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CONTENTS AuslandsGesch ftsAbsicherung der Bundesrepublik

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CONTENTS AuslandsGesch ftsAbsicherung der Bundesrepublik Powered By Docstoc
					                                     CONTENTS
                                                                                      Pages
1. INTRODUCTION                                                                       1
1.1 OBJECTIVE OF THE REPORT                                                           1
1.2 OVERVIEW OF CA MAU POWER PLANT PROJECT                                            1
1.3 DATA AND INFORMATION SOURCES                                                      2
1.4 METHODS AND PROCESSES IN THE PREPARATION OF EIA REPORT                            3
1.5 VIETNAMESE REGULATIONS, GUIDELINES AND ENVIRONMENTAL
                                                                                      4
    STANDARDS APPLIED FOR THE PROJECT
    1.5.1 Regulations and guidelines                                                  4
    1.5.2 Environmental standards applied for Ca Mau 2 power plant                    4
    1.5.3 Vietnamese standards applied for leaking, burning and exploding accidents   8
2. PROJECT DESCRIPTION                                                                9
2.1 PLANT LAYOUT                                                                      9
2.2 THE POWER PLANT                                                                   9
    2.2.1 Overview                                                                    9
    2.2.2 Power Generation Process                                                    9
    2.2.3 Plant Auxiliary System                                                      14
          2.2.3.1 Share facilities for CM1 and CM2 Power plant                        14
          2.2.3.2 Cooling water System                                                14
          2.2.3.3 Gas supply system for power plant                                   17
          2.2.3.4 Fuel Diesel Oil System                                              19
          2.2.3.5 Potable Water System                                                20
          2.2.3.6 Demineralized Water Supply System                                   21
          2.2.3.7 Wastewater Treatment System                                         21
          2.2.3.8 Electricity System                                                  21
          2.2.3.9 List of used Chemicals in power plant                               22
          2.2.3.10 Fire and Explosion Fighting System                                 23
          2.2.3.11 Communication System                                               24
2.3 CONSTRUCTION PHASE                                                                24
    2.3.1 Site Preparatory Works                                                      24
    2.3.2 Plant Construction                                                          24
          2.3.2.1 Main Plant                                                          24
          2.3.2.2 Wastewater Treatment System                                         25
          2.3.2.3 Cooling Water System                                                25
          2.3.2.4 Switchyard                                                          26
          2.3.2.5 Road system                                                         26
2.4 PROJECT DISCHARGE SOURCES                                                         26
    2.4.1 Emissions                                                                   26
    2.4.2 Effluents                                                                   26
    2.4.3 Solid wastes                                                                26
2.5 INVESTMENT FOR ENVIRONMENTAL PROTECTION                                           27
2.6 PROJECT SCHEDULE                                                                  28
3. EXISTING ENVIRONMENT OF THE PROJECT AREA AND ITS VICINITY                          29
3.1 SCOPE OF PROJECT AREA                                                             29
3.2 PHYSICAL ENVIRONMENT CHARACTERISTICS                                              29
    3.2.1 Climate characteristic                                                      29
    3.2.2 Air quality in the project area                                             33
    3.2.3 Hydrology Regime and Surface Water Quality                                  35
          3.2.3.1 Hydrology regime at Cai Tau Confluence Area                         35
          3.2.3.2 Water quality                                                       38
    3.2.4 Sediment quality                                                            40
    3.2.5 Hydrogeology and groundwater quality                                        41

                                             i
    3.2.6 Characteristics of Topography and Geology                               42
    3.2.7 Seismic, earthquake and erosion situation                               44
3.3 BIOLOGICAL CHARACTERISTICS                                                    44
    3.3.1 Terrestrial ecosystem                                                   44
    3.3.2 Aquatic ecosystem                                                       46
    3.3.3 Natural Ecological Conservations at the project area and the vicinity   48
3.4 SOCIO-ECONOMIC CONDITION                                                      48
    3.4.1 Population                                                              48
    3.4.2 Administrative boundary and future planning orientation                 49
    3.4.3 Agricultural activities                                                 49
    3.4.4 Industrial production activities                                        50
    3.4.5 Infrastructure and transportation                                       50
          3.4.5.1 Infrastructure                                                  50
          3.4.5.2 Transportation                                                  51
    3.4.6 Aquaculture                                                             52
    3.4.7 Health and Education                                                    52
    3.4.8 Cultural relics, archaeology and tourism                                52
    3.4.9 Existing pollution sources before having project                        53
4. POTENTIAL ENVIRONMENTAL IMPACT ASSESSMENT                                      55
4.1 CONSTRUCTION, INSTALLATION AND COMMISSION PHASES                              55
    4.1.1 Main sources of environmental impacts                                   55
    4.1.2 Impact on physical environment                                          56
          4.1.2.1 Air quality                                                     56
          4.1.2.2 Noise and vibration                                             58
          4.1.2.3 Impacts on water quality                                        58
          4.1.2.4 Impacts on soil quality                                         59
    4.1.3 Impacts on biological environment                                       60
    4.1.4 Interactions                                                            60
4.2 OPERATION PHASE                                                               61
    4.2.1 Main source of environmental impacts                                    61
    4.2.2 Impacts on physical environment                                         61
          4.2.2.1 Air quality                                                     61
          4.2.2.2 Impact on water quality                                         67
          4.2.2.3 Impacts on soil quality                                         82
    4.2.3 Impacts on Biological environment                                       83
4.3 DECOMMISSION PHASE                                                            83
    4.3.1 Impact on physical environment                                          84
    4.3.2 Impact on the biological environment                                    85
4.4 IMPACT ON THE SOCIO-ECONOMIC ENVIRONMENT                                      85
    4.4.1 Impact on popualation and labour force distributtion                    85
    4.4.2 Impact on Agricultural development                                      86
    4.4.3 Impact on industrial development                                        86
    4.4.4 Impacts on transportation and infrastructure                            86
    4.4.5 Impact on aquaculture and fishery                                       87
    4.4.6 Impact on public health                                                 88
    4.4.7 Impact on culture and landscape                                         88
    4.4.8 Impact on economy                                                       88
5. PRELIMINARY ENVIRONMENTAL RISK ASSESSMENT                                      89
5.1 SOME HAZARDOUS PROPERTIES OF FUELS USED IN THE PLANT                          89
5.2 RESOURCE SENSITIVITY ASSESSMENT                                               91
    5.2.1 Identify affected area                                                  91
    5.2.2 Sensitivity assessment of affected areas                                92
5.3 DAMAGE ASSESSMENT OF ACCIDENTS                                                92
    5.3.1 Gas leakage in the plant                                                92

                                              ii
          5.3.1.1 Possibility of gas leakage                                 92
          5.3.1.2 Environmental damages                                      93
    5.3.2 Fire/ explosion accident                                           94
          5.3.2.1 Risk of fire/ explosion accident                           94
          5.3.2.2 Environmental damage                                       95
    5.3.3. Oil and chemical spills                                           97
          5.3.3.1 Chemical spills                                            97
          5.3.3.2 Oil spills                                                 98
6. MITIGATING MEASURES FOR ENVIRONMENTAL IMPACTS                             99
6.1 MITIGATING MEASURES DURING CONSTRUCTING INSTALLING,
                                                                             99
    COMMISSIONING PHASES
    6.1.1 Soil quality                                                       99
    6.1.2 Air quality                                                        100
    6.1.3 Water quality                                                      100
    6.1.4 Minimize negative impacts to Economic – Social                     101
6.2 MITIGATION MEASURES FOR THE OPERATION PHASE                              102
    6.2.1 Air pollution treatment                                            102
    6.2.2 Noise                                                              103
    6.2.3 Waste water treatment and discharge                                103
    6.2.4 Collection and treatment system for solid waste                    105
    6.2.5 Prevent incidents                                                  106
6.3 DECOMMISSIONING PHASE                                                    107
7. ENVIRONMENTAL MANAGEMENT PLAN                                             109
7.1 ENVIRONMENTAL MANAGEMENT PLAN FOR THE PROJECT                            109
    7.1.1 Environment Management Program                                     110
    7.1.2 Checking and auditing environment management system                110
7.2 ENVIRONMENTAL MEASURING AND MONITORING PROGRAM                           110
    7.2.1 Monitoring Program for the Discharge Sources                       111
    7.2.2 Environment monitoring program in the vicinity                     112
7.3 ENVIRONMENTAL MANAGEMENT TRAINING PROGRAM                                115
7.4 EMERGENCY RESPONSE PLAN                                                  115
8. CONCLUSIONS                                                               117

LIST OF TABLES
            MAXIMUM ALLOWANCE LIMIT OF NOx, SO2 AND DUST IN AIR EMISSION OF THE
Table 1.1   THERMAL-POWER PLANT (TCVN 7440:2005) WITH CAPACITY > 600 MW, CONSTANT
            Kp = 0.7 FOR COMBINED CYCLE AND Kv = 1.2 FOR RURAL AREAS
            MAXIMUM LIMITS OF BASIC PARAMETERS IN THE AMBIENT AIR QUALITY (TCVN
Table 1.2
            5937:1995)
Table 1.3   MAXIMUM NOISE LIMIT IN PUBLIC AND RESIDENTIAL AREAS TCVN 5949:1995 (dB)
            ALLOWABLE VIBRATION LIMITS IN CONSTRUCTIVE AND INDUSTRIAL PRODUCTION
Table 1.4
            TCVN 6962:2001 FOR SURROUNDING ENVIRONMENT
            THE LIMIT VALUE OF POLLUTANT PARAMETERS AND THEIR CONTENTS IN
Table 1.5   INDUSTRIAL WASTEWATER WHEN DISCHARGING INTO THE AQUATIC
            PROTECTION AREA - TCVN 6984-2001
Table 1.6   SUMMARY OF VIETNAMESE STANDARDS APPLIED FOR CA MAU 2 POWER PLANT
Table 2.1   EMISSION DATA OF HEAT RECOVERY STEAM GENERATOR
Table 2.2   DESIGN PARAMETERS OF ADDITIONAL COOLING WATER SYSTEM
Table 2.3   ESTIMATION OF GAS DEMAND OF THE PLANT
Table 2.4   INPUT GAS CHARACTERISTICS OF THE POWER PLANT
Table 2.5   CHARACTERISTICS OF DIESEL OIL (DO) USED FOR CA MAU 2 POWER PLANT
Table 2.6   ESTIMATED DIESEL OIL DEMAND OF THE PLANT
Table 2.7   POTABLE WATER DEMAND OF CA MAU 2 POWER PLANT


                                        iii
Table 2.8    LISTS OF USED CHEMICALS OF THE POWER PLANT
Table 2.9    ENVIRONMENTAL PROTECTION FACILITIES OF CA MAU 2 POWER PLANT
Table 2.10   SCHEDULE OF CA MAU 1 & 2 POWER PLANTS
Table 3.1    STATISTICAL MONTHLY AVERAGE METEOROLOGICAL DATA AT CA MAU STATION
             (1980 - 2004)
Table 3.2    COMPARISON BETWEEN THE AVERAGE EVAPORATION AND RAINFALL IN THE
             DRY SEASON (1980-2004)
Table 3.3    ANNUAL AND SEASONAL RAINFALL IN CA MAU
Table 3.4    THE MAXIMUM MONTHLY RAINFALL (MM) IN CA MAU IN COMPARISON WITH THE
             STATISTICAL MEAN VALUES (1960-2004)
Table 3.5    THE AVERAGE RAINFALL (MM) IN CA MAU STATION
Table 3.6    ANALYTICAL RESULTS OF AIR QUALITY (day average) AT PROJECT AREA AND CAI
             TAU RESIDENTIAL AREA IN 2005
Table 3.7    PARAMETERS OF NOISE AND VIBRATION
Table 3.8    SUMMARY OF CURRENT CHARACTERISTIC AT TAC THU STATION
Table 3.9    HYDROLOGICAL CHARACTERISTICS IN THE CA MAU GAS-POWER-FERTILIZER
             COMPLEX IN BOTH DRY AND RAINY SEASONS, 2002
Table 3.10   PHYSIO-CHEMICAL PARAMETERS OF SURFACE WATER AT CA MAU POWER
             PLANT IN 2005
Table 3.11   ANALYSED RESULTS OF CHEMICAL PARAMETERS OF SURFACE WATER
Table 3.12   HEAVY METAL CONTENT IN SURFACE WATER (mg/l)
Table 3.13   HEAVY METAL CONTENTS IN SEDIMENT
Table 3.14   ANALYTICAL RESULTS OF GROUNDWATER QUALITY AT THE PROJECT AREA
Table 3.15   RESULT OF HEAVY METAL CONTENTS IN GROUNDWATER AT THE PROJECT AREA
Table 3.16   ANALYTICAL RESULT OF METAL CONTENT IN SOIL SAMPLES (µg/g)
Table 3.17   THE ANALYTICAL RESULTS OF PHYTOPLANKTON AT THE PROJECT AREA
Table 3.18   THE ANALYTICAL RESULTS OF ZOOPLANKTON AT THE PROJECT AREA
Table 3.19   ANALYTICAL RESULTS OF BENTHOS AT THE PROJECT AREA
Table 3.20   POPULATION AND LABOUR DISTRIBUTION AT HAMLETS 1, 3 AND 6
Table 3.21   THE DAILY NUMBER OF PASSENGER BOATS IN CAI TAU CONFLUENCE – KHANH
             AN VILLAGE COMMUNE
Table 3.22   AREA AND YIELD OF FISHERY AQUACULTURE IN U MINH DISTRICT
Table 3.23   FIRE FOREST ACCIDENTS AT THE BEGINNING OF 2005
Table 4.1    MAIN SOURCES OF ENVIRONMENTAL IMPACTS DURING CONSTRUCTION/
             INSTALLATION AND COMMISSIONING PHASES
Table 4.2    ESTIMATION EMISSION VOLUME FROM OPERATION OF CONSTRUCTION
             EQUIPMENT IN CONSTRUCTION AND INSTALLATION PHASE
Table 4.3    COMPONENTS AND EMISSION VOLUME IN TESTING PROCESS FOR CA MAU 2
             POWER PLANT
Table 4.4    LOADS AND CONTENT OF REGULAR EMISSION GASES THROUGH THE STACK OF
             CA MAU 2 POWER PLANT
Table 4.5    THE HEIGHT AND DISTANCE OF AMBIENT BUILDINGS TO THE MAIN STACK OF CA
             MAU 2 POWER PLANT
Table 4.6    MAXIMUM AVERAGE GROUND CONCENTRATION OF POLLUTANTS WHEN
             RUNNING FOR CA MAU 2 POWER PLANT FOLLOW OPTION 1&2 – WITH OBSTACLE
Table 4.7    MAXIMUM AVERAGE GROUND CONCENTRATION OF POLLUTANTS WHEN
             RUNNING FOR THE BOTH PLANT 1&2 FOLLOWING OPTION 3&4 – WITH OBSTACLE
Table 4.8    OPTIONS FOR COOLING WATER INTAKE AND DISCHARGE FOR CM1 AND CM2
             POWER PLANTS
Table 4.9    AVERAGE FLOW OF CAI TAU – ONG DOC RIVER (m3/s) IN THE DRY SEASON WHEN
             THE POWER PLANTS COME INTO OPERATION (In case of opening Tac Thu sluice )
Table 4.10   AVERAGE FLOW RATE OF CAI TAU – ONG DOC RIVER (m3/s) IN THE DRY SEASON
             WHEN POWER PLANT COMES INTO OPERATION (In case of Tac Thu sluice is closed)
Table 4.11   AVERAGE AND MAXIMUM TEMPERATURE INCREASE ALONG CAI TAU – ONG DOC
             RIVER BY 2 DISCHARGED OPTIONS IN 6 MONTHS OF DRY SEASON- DISCHARGED
             TEMPERATURE OF 35oC

                                           iv
Table 4.12    AVERAGE AND MAXIMUM TEMPERATURE INCREASES ALONG CAI TAU-ONG DOC
              RIVER - DISCHARGED TEMPERATURE OF 40oC
Table
              INDUSTRIAL WASTEWATER TYPES OF THE CM2 POWER PLANT
4.13
Table 4.14    THE AVERAGE BOD (mg/l) ALONG CAI TAU – ONG DOC RIVER WHEN BOTH POWER
              PLANTS DISCHARGE INTO CAI TAU RIVER
Table 5.1     LIMITS OF FLAMMABLE MIXTURE FORMING OF SOME ALKANES
Table 5.2     CO2 CONTENT IN THE AIR AND CORRELATIVE CONSEQUENCES
Table 5.3     POSSIBILITY OF GAS LEAKAGE IN THE CA MAU 2 POWER PLANT
Table 5.4     GAS DISPERSION RESULT BY SAFETI MODEL
Table 5.5     SUMMARY OF FIRE AND EXPLOSION ACCIDENTS IN THE POWER PLANT
Table 5.6     EFFECTS FROM THERMAL RADIATION
Table 5.7     OVERPRESSURE EFFECTS
Table 5.8     AFFECTED SCALE OF FIRE/ EXPLOSION BY SAFETI MODEL
Table 5.9     POTENTIAL OIL SPILLS IN THE POWER PLANT AND THE DO IMPORTING JETTY
              AREA
Table 7.1     REGULAR MONITORED PARAMETERS IN CA MAU 2 POWER PLANT
Table 7.2     ENVIRONMENTAL SAMPLING LOCATIONS AT CA MAU POWER PLANT (In December,
              2005)
Table 7.3     PERIOD MONITORING PARAMETERS AND LOCATIONS AT SURROUNDING AREA OF
              POWER PLANT
Table 7.4     MONITORING FREQUENCY OF SURROUNDING ENVIRONMENT OF THE POWER
              PLANT

LIST OF FIGURES
Figure 2.1    DIAGRAM LAYOUT OF CA MAU 2 POWER PLANT
Figure 2.2    MODEL OF COMBINED CYCLE POWER PLANT
Figure 2.3    POWER GENERATION PROCESS DIAGRAM OF THE PLANT
Figure 2.4    DIAGRAM OF COOLING WATER SYSTEM OF CA MAU 2 POWER PLANT
Figure 2.5    SYSTEM TO PROVIDE FUEL GAS
Figure 2.6    LAYOUT DISTRIBUTION OF CA MAU 2 POWER PLANT
Figure 3.1    WIND ROSE AT CA MAU STATION
Figure 3.2    LOCATION OF ENVIRONMENTAL SAMPLING STATIONS IN CA MAU POWER PLANT
Figure 3.3    LOCATION OF HYDROLOGY MEASURING STATIONS IN PROJECT AREA
Figure 3.3a   MAP OF MAXIMUM FLOODING IN 2000
              GENERAL PLANNED LAYOUT OF RESETTLEMENT AREA SERVING FOR
Figure 3.4
              INDUSTRIAL ZONES AND CENTER OF KHANH AN TOWN IN FUTURE
Figure 3.5    THE MAIN WATERWAY ROUTES TO PROJECT AREA
              DIAGRAME OF COOLING WATER INTAKE SITE, DISCHARGE SITES IN OPTIONS AND
Figure 4.1
              TRANSECT SITES DESCRIBING MODELING RESULTS
              AVERAGE FLOW ALONG CAI TAU – ONG DOC RIVER IN CASE OF WITHOUT AND
Figure 4.2
              WITH TWO POWER PLANTS – AS OPENING TAC THU SLUICE
              AVERAGE FLOW RATE ALONG CAI TAU – ONG DOC RIVER WITHOUT AND WITH
Figure 4.3
              TWO POWER PLANTS (Case of Tac Thu closing)
              HIGHEST TEMPERATURE INCREASE BY TWO DISCHARGE OPTIONS DURING 6
Figure 4.4
              DRY MONTHS (DISCHARGED TEMPERATURE OF 35OC)
              AVERAGE TEMPERATURE INCREASE BY TWO DISCHARGE OPTIONS DURING 6
Figure 4.5
              DRY MONTHS (DISCHARGED TEMPERATURE OF 35OC)
              AVERAGE TEMPERATURE INCREASES ALONG THE RIVER BY TWO DISCHARGED
Figure 4.6
              OPTIONS IN SIX DRY MONTHS – DISCHARGED TEMPERATURE OF 40oC
Figure 4. 7   MAXIMUM TEMPERATURE INCREASES ALONG RIVER BY TWO DISCHARGED
              OPTIONS IN SIX DRY MONTHS – DISCHARGED TEMPERATURE OF 40oC
Figure 6.1    WASTEWATER TREATMENT FLOWCHART OF CA MAU 2 POWER PLANT
Figure 7.1    SAMPLING SITES OF WATER ENVIRONMENT MONITORING FOR CA MAU 1 AND CA
              MAU 2 POWER PLANTS

                                         v
vi
                        ABBREVIATION
ANSI      : American national standards institute
BLEVE     : Boiling liquid expanding vapor explosion
BOD       : Biological oxygen demand
CCP       : Cycle power plant
CM1       : Ca Mau 1
CM2       : Ca Mau 2
CPMB      : Ca Mau Gas – Power – Fertilizer Project Management Board
CW        : Cooling Water
DC        : Drill Collar
DEIA      : Detail Environmental Impact Assessment
DO        : Diesel Oil
DTS       : Total oil content
EIA       : Environmental Impact Assessment
EPC       : Engineering Procurement Construction
E-SE      : East-South East
EVN       : Electricity Vietnam
FEED      : Front End Engine Design
GT        : Gas turbine
HP        : High pressure
HRSG      : Heat recovery steam generators
HSE       : Health, Safety and Environment
IGPF      : Integrated Gas – Power – Fertilizer
IP        : Intermediate pressure
ISC-ST3   : The Industrial Source Complex Short-Term
LFL       : Low flammable limit
LP        : Low pressure
LPG       : Liquid Petroleum Gas
MONRE:    : Ministry of Natural Resource and Environment
MoSTE     : Ministry of Science, Technology and Environment
NFPA      : National Fire Prevention Association
ODA       : Organization Development Assistance
OREDA     : Offshore Reliability Data
PP        : Power plant
RDCPSE    : Research and Development Center for Petroleum Safety and Environment
RO        : Reverse Osmosis
SE        : South East
S-SE      : South-South East
ST        : Steam turbine
TCVN      : Vietnamese standards
THC:      : Total hydrocarbon content
ULF       : Upper flammable limit
UPS       : Uninterruptible Power Supply
USEPA     : United State of Environmental Protection Agency
UVCE:     : Unconfined vapor cloud explosion
VCE       : Vapor cloud explosion
VND       : Vietnamese Dong
VOC       : Volatile Organic Compound
WHO       : World Health Organisation
W-SW      : West-South West
WTS       : Wastewater treatment system
                               REFERENCES
[1]    PETROVIETNAM - NĐ-2005-07 PROJECT, DECEMBER, 2005
       Investment Project of Ca Mau 2 Combined Cycle Power Plant - Volume 1:
       General explanation.

[2]    SOUTHERN HYDRO METEOROLOGICAL CENTER, 2005.
       Hydro Meteorological Report of Ca Mau, during 1980 – 2004.

[3]    DEPARTMENT OF NATURAL RESOURCE AND ENVIRONMENT OF CA MAU,
       2005
       Existing Environmental Report of Ca Mau province, 2005

[4]    RESEARCH & DEVELOPMENT CENTER FOR PETROLEUM SAFETY AND
       ENVIRONMENT (RDCPSE), DECEMBER, 2005.
       Supplemental Environmental Baseline Study Report for Ca Mau Power Plant

[5]    RESEARCH & DEVELOPMENT CENTER FOR PETROLEUM SAFETY AND
       ENVIRONMENT (RDCPSE), JANUARY, 2004.
       Detail EIA Report for Ca Mau Power Plant Project

[6]    LUU VAN THUAN-2005
       Hydrology Report of Cai Tau, Trem and Ong Doc Rivers.

[7]    PEOPLE'S COMMITTEE OF CA MAU PROVINCE, JULY, 2002
       Existing Environmental Assessment Survey for predicting potential reserve,
       quality and production planning of underground water in Ca Mau province.

[8]    INFORMATIC REMOTE SENSING DEPARTMENT - HO CHI MINH PHYSICAL
       SUBINSTITUTE, DECEMBER, 2002.
       Study on Shoreline Erosion and Variation for the Southwest Coastal Area from
       Ca Mau cape to Cambodian border using Satellite images

[9]    DEPARTMENT OF SCIENCE, TECHNOLOGY AND ENVIRONMENT OF CA MAU
       PROVINCE
       Report on Existing Erosion along rivers in Ca Mau province.

[10]   GOVERNMENTAL SCIENTIFIC COMMITTEE
       General Basic Surveying Program for the Mekong Delta 60-02

[11]   PEOPLE COMMITTEE OF KHANH AN COMMUNE, 2005
       Statistic data of social - economic situation of Khanh An Commune

[12]   CONSTRUCTIONAL CONSULTING COMPANY, MINISTRY OF CONSTRUCTION,
       2000
       Existing and protection and development Planning for Coastal Mangrove
       Forest in the Mekong Delta

[13]   MANAGEMENT BOARD OF WHARF A, WARD 1, CA MAU CITY, 2002
       Number of Daily boats/barges back and forth within six initial months of 2002

[14]   NGO CHI HUNG, DEPARTMENT OF SCIENCE, TECHNOLOGY AND
       ENVIRONMENT OF CA MAU PROVINCE, 2002
       EIA Report for forest fire and its impacts on social- economic condition



                                           i
[15]   WORLD HEALTH ORGANIZATION, GENEVA, 1993
       Assessment of sources of Air, Water, and Land Pollution – A Guide to
       Rapid Source Inventory Techniques and Their Use in Formulating
       Environmental Control Strategies Part one: Rapid Inventory techniques
       in Environmental Pollution by Alexander P. Economopoulos –
       Democritor University of Thrace

[16]   PROF. Ph.D PHAM NGOC ĐANG, HA NOI SCIENTIFIC AND
       TECHNOLOGICAL PUBLISHER, 1992.
       Air Pollution in Urban and Industrial Area.

[17]   ASSOC. PROF. Ph.D. HOANG VAN BINH (NOVEMBER, 1996),
       HO CHI MINH CITY INSTITUTE OF HYGENE AND PUBLIC HEALTH
       Professional Document - Industrial Toxicity and Prevention of infecting
       poisons in producing process (Volume 1),

[18]   RDCPSE & DNV TECHNICA, APRIL, 2002
       Quantitative Risk Assessment for Dinh Co - Thi Vai pipeline

[19]   AKIRA WADA ET ALL. JAPAN - AUGUST, 1975
       Study on adaptability of prediction method of simulation analysis for
       diffusion of discharged warm water in the sea

[20]   ENVIRONMENTAL BUREAU - MINISTRY OF SCIENCE, TECHNOLOGY
       AND ENVIRONMENT, 1999
       Guidelines for preparation and appraisal of Environmental Impact
       Assessment Reports of thermal power plant project.




                                   ii
Revised report on DEIA for Ca Mau Power Plant Project (Part of DEIA for Ca Mau 2 Power Plant)          1




Section       1.                                          INTRODUCTION


1.1     OBJECTIVE OF THE REPORT
Ca Mau Power Plant sited into Ca Mau – Gas – Power – Fertilizer Project was approved to
build at Khanh An commune, U Minh district, Ca Mau province by the Government in
October, 2001. The project is invested by Petrovietnam and is directly managed by Ca Mau
Gas – Power – Fertilizer Project Management Board (CPMB).

According to the conclusion of the Head of State Guidance for the key Petroleum projects,
Vice Prime Minister Nguyen Tan Dung, in the conference dated 1st September 2005, noticed
that Ca Mau 2 power plant will be built to satisfy the deficient power of the country and
effectively utilizes the natural gas resource at the Southwest continential shelf.

This environmental impact assessment (EIA) report is complied according to the
requirements of Petrovietnam and Ministry of Natural Resource and Environment (MONRE).
Objectives of this report include:
−     To update the existing environmental conditions at the project area for revised Ca Mau
      power plant project and its vicinity;
−     To assess supplementary potential environmental impacts caused by Ca Mau 2 power
      plant implementation and propose mitigation measures to minimise the negative
      environemntal impacts and satisfy the Vietnamese law requirements;
−     To provide the scientific basis for the Ministry of Natural Resource and Environment
      and Department of Natural Resource and Environment of Ca Mau to assess the
      compliance of the project owner 's requirement proposed in the EIA report.


1.2      OVERVIEW OF CA MAU POWER PLANT PROJECT
The revised Ca Mau power plant project includes two (02) plants: Ca Mau 1 power plant and
Ca Mau 2 power plant. The development process of two plants is summarized as follows:

    Ca Mau 1 power plant approved in October 2001 is located in the Gas – Power –
    Fertilizer complex at hamlet 1, Khanh An commune, U Minh district, Ca Mau province.
    This is a Combined Cycle Gas Turbine Power Plant with design capacity of 750 MW
    which can use both natural gas or DO fuel. According to the technical design approved
    by the Minister of Industry No 299/QĐ-NLDK on 25th February 2004, the plant’s
    configuration is multi–structure one including two gas turbine generators, two heat
    recovery steam generators (HRSG), 1 condensing steam turbines generator and
    accompanied power generators. The detailed environmental impact assessment report
    of Ca Mau 1 power plant was carried out in 2003 and approved on 23rd April 2004 by
    Decision No 460/QĐ-BTNMT of the Ministry of Natural Resource and Environment
    (Appendix 1).


CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau Power Plant Project (Part of DEIA for Ca Mau 2 Power Plant)          2


    To overcome the electricity deficiency in the dry season of 2007-2008, the Government
    requests that Ca Mau 1 power plant will be run with two stages: i) put the Single Cycle
    Power plant to generate power in March 2007 and ii) then, complete and change into the
    Combined Cycle Power plant at the designed capacity 750MW.

    After calculation in detail design, emission gas content at the discharge sources is
    different with the mentioned emission gas in the approved detail EIA report for Ca Mau 1
    power plant. However, when comparing with the current Vietnamese standards, the
    emission gas content at the top of stack is still lower than TCVN 7440-2005. So, the
    plant's main stack height is considered to reduce to 40m and the bypass-stack height is
    considered to reduce to 30m and it still satisfies Vietnamese standards for emission gas.

    About wastewater of Ca Mau 1 power plant, according to the approved design, the
    cooling water of Ca Mau 1 power plant will be discharged into Cai Tau river, and the
    industrial effluents discharged from plant will be treated by the plant's treatment system,
    then routed to biological test pond together with the treated wastewater of Ca Mau
    fertilizer plant and finally discharged into Ong Doc river. But now, the fertilizer plant has
    not yet built and the biological pond is proposed to build in complex constructions of the
    fertilizer plant. So, the discharge site of treated industrial wastewater of Ca Mau 1 power
    plant is changed to discharge into Cai Tau river. The supplemented EIA for the above-
    mentioned changes was conducted in November 2005 and approved by the Ministry of
    Natural Resource and Environment according to Decision No 297/QĐ-BTNMT of March
               R




    23, 2006 (Appendix 1).

    Ca Mau 2 power plant project is approved by the Petrovietnam Management Board
    according to the Decision No 1459/QĐ-HĐQT of February 15, 2006 for revised Ca Mau
    power plant project. Ca Mau 2 power plant has designed capacity of 750 MW and
    similar configuration to Ca Mau 1 power plant. It is planned to be built on the area of Ca
    Mau fertilizer plant in Ca Mau gas-power-fertilizer complex. The main fuel for Ca Mau 2
    power plant 's operation is natural gas from PM3 - CAA block and Cai Nuoc block
    provided by gas distribution station sited in the gas-power-fertilizer complex. Ca Mau 2
    power plant will also be built at the same time with the Ca Mau 1 power plant which is
    planned to complete in 2008. The detail description of Ca Mau 2 power plant will be
    presented in chapter 2 of this report.

    The name of this report is taken according to the approved project name by the
    Government: “Revised Ca Mau Power Plant Project”. Part of EIA is newly made for Ca
    Mau 2 Power Plant. Therefore, this report is named “Revised report on DEIA for Ca Mau
    Power Plant Project (Part of DEIA for Ca Mau 2 Power Plant)”.

1.3      DATA AND INFORMATION SOURCES
The technical data used in this report is supplied mainly by Ca Mau CPMB and the design
consultant. The environmental data is carried out, measured, analysed and assessed by
RDCPSE. Specially, the economic and social data is collected from the local authorities and
related departments. Detail main used document are summarized as follows:
    The general design document of Ca Mau 1 power plant project is provided by Ca Mau
    CPMB in November, 2005.
    General explanation for investment project of Ca Mau 2 power plant - volume 1,
    December, 2005 together with technical drawings is provided by Ca Mau CPMB.
    Supplementary meteorological data in 2003 - 2004 is provided by Southern
    Meteorological Station.
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    The data of supplementary baseline environmental survey at the Ca Mau power plant
    area was conducted by RDCPSE in the sampling, measuring, vegetation field survey
    and meeting with local authorities from 19 –24th December, 2005.
    The revised environmental protection law and the current environmental standards .

1.4     METHODS AND PROCESSES IN THE PREPARATION OF EIA
        REPORT
This detail EIA report is prepared in accordance with the Guidelines for preparation of the
EIA report for investment projects (Circular No. 490/1998/TT-MoSTE) issued by MoSTE in
1998.
The main methods used in the preparation of this EIA report are as follows:
1. Statistical method: is used to treat the environmental analytical data, and the meteo-
   hydrological and socio-economic data;
2. Modeling method: is used to calculate and stimulate the air emission processes, the
   wastewater and the thermal dispersion caused by project activities. Some mathematic
   models are used for preparing this report including:
        Air dispersion modeling ISCST3 - version 3.2 is used to assess the level of air
        dispersion in operational process of Ca Mau power plant. This model is established
        and developed by United State of Environmental Protection Agency (USEPA) and is
        accredited by international organizations to use as a calculating and forecasting tool
        of impacts to air quality by industrial air emission;
        Hydraulic modeling SAL: is used to calculate the variation of hydraulic regime due to
        the cooling water intake activities of the project. This model was established by
        Assoc.Prof.Dr. Nguyen Tat Dac and is applied in calculating the hydraulic regime
        and the drainage ability of the whole Mekong Delta.
        Wastewater dispersion modeling is used to calculate and to stimulate the organic
        wastewater dispersion and thermal dispersion process on the river/ canal system
        affected by the tides under different uses.
 3. Field survey and measurement method: is used to take samples, field measure and
    analyse in the laboratories (air, water, soil, sediment and biology samples) at the project
    area. Moreover, this method is used to survey the vegetation cover, take the
    photographs and interview in the field trips for collecting the existing environment and
    socio-economic situation;
4. Social investigation method: is used to interview the authorities, departments and local
   residents at the project area.
5. Comparative method: is used to evaluate environmental quality of air, soil, water,
   sediment and biology in comparison with existing current Vietnamese and International
   environmental standards;
During prepation process this report, the project owner has co-operated closely with
RDCPSE and the design consultant (Power Engineering Consulting Company No.2 and
Electrowatt-Econo Consultant Company), general LILAMA contractor and Petrovietnam
Health, Safety and Environment Division in order to ensure the accuracy and consistency
from the used information. Furthermore, the project owner has co-operated closely with the
local authorities, especially Department of Natural Resource and Environmet, Fishery
Department, Agricultural and Rural Development Department and Construction Department
in assessing and secllecting of wastewater discharge sites of the revised power plant
project.
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1.5 VIETNAMESE REGULATIONS, GUIDELINES AND
    ENVIRONMENTAL STANDARDS APPLIED FOR THE PROJECT
1.5.1 Regulations and guidelines

The current laws, regulations and guidelines are used to refer in the report including:
    Revised Law on Environmental Protection, 2006.
    Government Decree No.175-CP dated on October 18,1994 providing guidane for
    implement of the Law on Environmental Protection;
    Government Decree No.143/2004/NĐ-CP dated July 12, 2004 revising and
    supplementing article 14 of Decree No.175-CP dated on October 18,1994 providing
    guidane for implement of the Law on Environmental Protection;
    Approved Decision of Feasibilities Study report No.1333/QD-TTg dated October 8th,
    2001 issued by Prime Minister;
    Approved Decision of Bidding plan No.444/QD-TTg dated June 6th, 2002 issued by
    Prime Minister;
    Approved Decision of Front End Engine Design (FEED) No.299/QĐ-NLDK dated
    February 25th, 2004 issued by Minister of Industrial Ministry;
    Governmental Decree No.121/2004/NĐ-CP dated May 12 th, 2004 providing the
    administrative purnishment, and environmental prtection.
    Approved Decision No.1195/QĐ-TTg dated November 11, 2005 on providing instructive,
    specific policies for constructive investment of urgent power projects during 2006-2010.
    Governmental Decision No.155/1999/QD-TTg dated July 16th, 1999 providing the
    regulations on hazadous waste management;
    Circular No.490/1998/TT-KHCN&MT dated January 29th, 1998 issued by Ministry of
    Science, Technology and Environment on guidelines for preparartion and appraisal of
    Environmental Impact Assessment Reports of Investment Project;
    Circular No.2262 market-Mtg of December 26th, 1995 issued by Ministry of Science,
    Technology and Environment on guiding of oil spills recovery;
    Petroleum law dated July 6th, 1993 and Governmental Decree 84/CP dated December
    17th, 1996 regulating details of the implementation of the petroleum law;
    Governmental Decision No.41/1999/QD-TTG dated March 8th, 1999 providing the
    regulations of safety management for the petroleum activities;
    Decision No.395/1998/QD-KHCN&MT of April 10th, 1998 issued by MoSTE about
    Regulations for Environmental Protection in searching, exploring, developing mines and
    exploiting, storing, transporting, processing oil and related services;
    Vietnamese standards issued by Ministry of Science, Technology and Environment in
    1995, 2001 and 2005.

1.5.2 Environmental standards applied for Ca Mau 2 power plant

1. Vietnamese standards about air emission limits
In 2005, Ministry of Science, Technology and Environment issued "Air emission standards
for thermo-power industry plant TCVN 7440:2005" providing the allowance maximum
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This standard is applied to assess and appraise environmental requirements for the thermo-
new power plants or operating thermo-power plants that is improved bigger and widen. The
maximum allowance limit of pollutants (NOx, SO2 and dust) in air emission source of thermo-
power plant is given in Table 1.1.

Table 1.1 MAXIMUM ALLOWANCE LIMIT OF NOx, SO2 AND DUST IN AIR EMISSION OF
    THE THERMAL-POWER PLANT (TCVN 7440:2005) WITH CAPACITY > 600 MW,
   CONSTANT Kp = 0.7 FOR COMBINED CYCLE AND Kv = 1.2 FOR RURAL AREAS
                                                                                                Unit: mg/Nm3
                                                           Used fuel
 Parameters
                            Coal Burning                   Oil Burning                 Gas Burning
               3
 NOx (mg/Nm )                 840 (1000)                     504 (600)                   210 (250)
               3
 SOx (mg/Nm )                  420 (500)
                                                             420 (500)                   252 (300)

 Dust (mg/Nm3)                168 (200)                    126 (150)                  42 (50)
Notes: the value in the brackets () is the value in TCVN 7440:2005 which haven't revised by the
project constant Kp & Kv.

Owing to standard of TCVN 7440:2005 doesn't stipulate for CO content, so, the maximum
allowance limit of CO in air emission will comply with the standard TCVN 6993:2001 with A
technology (KCN = 0.6), constant Karea = 1.2 and discharge flow Q3 > 20,000 m3/h is 180
mg/Nm3.

For the ambient air environment, Ca Mau 2 power plant will comply with the maximum
allowance limits on ground according to TCVN 5937:1995 (Table 1.2).
                     Table 1.2 MAXIMUM LIMITS OF BASIC PARAMETERS
                      IN THE AMBIENT AIR QUALITY (TCVN 5937:1995)

        Parameters            Average of 1 hour        Average of 8 hours         Average of 24 hours
    CO (mg/m3)                      40                        10                           5
    NO2 (mg/m3)                     0.4                        -                          0.1
    SO2 (mg/m3)                     0.5                        -                          0.3
    Pb (mg/m3)                       -                         -                        0.005
    O3 (mg/m3)                      0.2                        -                         0.06
    Suspended dust                  0.3                        -                         0.2
    (mg/m3)
Source: 31 compulsory Vietnamese Standards – Hanoi, 2002
Note: (-) : undefined


2. Vietnamese standards about noise and vibration

−    Noise limits for surrounding environment

Noise caused by project implementation for commercial and service area and factories
intermingling in residential area will be applied to TCVN 5949:1995 (Table 1.3).


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       Table 1.3 MAXIMUM NOISE LIMIT IN PUBLIC AND RESIDENTIAL AREAS TCVN
                                   5949:1995 (dB)

 No. Area                                                                            Time
                                                                                     From 6h           From18h From
                                                                                     to 18h            to 22h  22h to
                                                                                                               6h
 1       Quiet areas: Hospital, library, sanatoria,                                  50                45      40
         kindergarten, schools
 2       Residential, hotels, houses, administrative office                          60                55        45
 3       Commercial and service areas                                                70                70        50
 4       Small industrial factories intermingling in residential                     75                70        50
         areas
Source: 31 compulsory Vietnamese Standards – Hanoi, 2002

−    Vibration limits for surrounding environment

Vibration caused by project constructive and industrial production activities for surrounding
environment will be applied to TCVN 6962:2001 (Table1.4).

     Table 1.4 ALLOWABLE VIBRATION LIMITS IN CONSTRUCTIVE AND INDUSTRIAL
          PRODUCTION TCVN 6962:2001 FOR SURROUNDING ENVIRONMENT

 No      Area                                                   Vibration limits in                  Vibration limits in
 .                                                           construction activity (dB)           production activity (dB)

                                                              7h-19h            19h-7h                6h-18h     18h-6h
 1       Quiet areas                                             75          Basic level*              60          55

 2       Residential, hotels, houses,                            75          Basic level*              65          60
         administrative office
 3       Small industrial factories                              75          Basic level*              70          65
         intermingling in residential areas
Source: 31 compulsory Vietnamese Standards – Hanoi, 2002
Note * Basic level is vibration level measured when without facilities working in the assessed area


3. Vietnamese environmental standard of wastewater
−    Discharging cooling water:
According to the design, Ca Mau 2 power plant will take cooling water from Cai Tau river
through the cooling water canal that is used together with Ca Mau 1 power plant. In the
operational phase, the cooling water system doesn't take part in the technological process,
but is used for indirect thermal exchange. So, the cooling water can be considered as non-
pollution discharged water, so it hasn't to comply the Vietnamese Environmental standards
of wastewater. As for the temperature of cooling water, Ca Mau 2 power plant will strictly
comply the Vietnamese standard TCVN 5945:1995 with cooling water temperature ≤ 40oC
into the received environment that used for the purposes of water traffic, irrigation, swimming
and fishery aquaculture.

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−        Discharging industrial wastewater

Industrial wastewater considered as the discharge water from production process will be
treated to meet the Vietnamese standard before discharging into environment. According to
the discharged quantity and river flow, the limit value of pollutant parameters and content in
the treated industrial wastewater of Ca Mau 2 power plant when discharging into the river will
not be exceed the limit value in column B of TCVN 6984:2001 (Table 1.5) applied for the
aquatic protection area.

    Table 1.5 THE LIMIT VALUE OF POLLUTANT PARAMETERS AND THEIR CONTENTS
         IN INDUSTRIAL WASTEWATER WHEN DISCHARGING INTO THE AQUATIC
                          PROTECTION AREA - TCVN 6984-2001
                                                                   3                           3                              3
    No.    Parameters                                 Q>200 m /s                 Q= 50 - 200 m /s                  Q<50 m /s
                                               F1           F2          F3      F1      F2          F3      F1          F2         F3
    1      Color, Co-Pt at pH=7                50          50           50      50      50         50       50          50         50
    2      Smell, Sensibility                 light        light       light   light   light       light   light     light        light
    3      TSS mg/l                           100          100         100      90      80         80       80          80         80
    4      PH                                 6-8.5      6-8.5         6-8.5   6-8.5   6-8.5   6-8.5       6-8.5    6-8.5         6-8.5
                        o
    5      BOD5 (20 C) mg/l                    50          45           40      40      35         30       30          20         20
    6      COD (mg/l)                         100          90           80      80      70         60       60          50         50
    7      As (mg/l)                           0.1         0.1         0.1     0.08    0.08    0.08        0.05      0.05         0.05
    8      Cd (mg/l)                          0.02         0.02        0.02    0.01    0.01    0.01        0.01      0.01         0.01
    9      Pb (mg/l)                           0.5         0.5         0.5     0.5     0.5         0.5     0.5          0.5       0.5
    10     Fe (mg/l)                            5           5           5       4       4           4       3           3          3
                 -
    11     CN (mg/l)                           0.1         0.1         0.1     0.05    0.05    0.05        0.05      0.05         0.05
    12     Oil & Mineral petrol (mg/l)         10           5           5       10      5           5       5           5          5
    13     Fat (mg/l)                          20          20           20      20      10         10       10          10         10
    14     Organic Phosphor (mg/l) l            1           1          0.8     0.8     0.5         0.5     0.5          0.5       0.5
    15     Total Phosphor (mg/l)               10           8           8       6       6           6       5       5              5
             -
    16     Cl (mg/l)                          1000       1000          1000    800     800         800     750       750          750
    17     Surfactant (mg/l)                   10          10           10      5       5           5       5           5          5
    18     Coliform MPN/100ml                 5000       5000          5000    5000    5000    5000        5000     5000          5000
    19     PCB (mg/l)                         0.02         0.02        0.02    0.01    0.01    0.01        0.01      0.01         0.01
Source: 31 compulsory Vietnamese Standards – Hanoi, 2002
                               3
Notes:      -Q: river flow, m /s
                                       3
    −       F: discharged capacity , m /day (24 hours)
                            3                     3
    −       F1: from 50 m /day to lower than 500m /day
                              3                      3
    −       F2: from 500 m /day to lower than 5000m /day
                                     3
    −       F3: equal or over 5000m /day


The project owner has responsibilities to control emission gas, liquid effluents, and solid
wastes generated from the project operation as well as monitoring the ambient environment
surrounding project area in accordance with the environmental criteria listed in above tables
during the project operation life.

In general, Vietnamese standards applied for Ca Mau 2 power plant are listed in Table 1.6.




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                Table1.6 SUMMARY OF VIETNAMESE STANDARDS APPLIED
                             FOR CA MAU 2 POWER PLANT
 No. Parameters                                                                Standards
 1   NOx, SOx and dust at discharge sources                                    TCVN 7440:2005
     CO at discharge sources                                                   TCVN 6993:2001
 2   CO, NOx, Sox and dust in surrounding environment                          TCVN 5937:1995
 3   Noise in surrounding environment                                          TCVN 5949:1995
 4   Vibration in surrounding environment                                      TCVN 6962:2001
 5   Temperature of cooling water                                              TCVN 5945:1995
 6   Industrial wastewater                                                     TCVN 6984:2001

1.5.3 Vietnamese standards applied for leaking, burning and exploding
accidents

The gas leakage and fire detection and protection system will be designed, installed and
operated and met the Vietnam standards (TCVN). The Vietnamese Standards applied to fire
and gas leakage are listed as follows:
−   TCVN 3254-89:                 Fire protection, general safety and requirements;
−   TCVN 35738-93:                Fire detection and alarm system, technical requirements;
−   TCVN 4090-85:                 Main oil and oil products pipelines – design principle.
−   TCVN 5307-91:                 Oil and oil product storage tank;
−   TCVN 5739-1993:               Fire fighting equipment – coupling heads;
−   TCVN 6379-1998:               Fire fighting equipment. Fire fighting water pipe. Technical
    Requirements;
−   TCVN 2622-1995:               Fire Protection for Buildings. Design Requirements;
− TCVN 5760- 1993:              Fire extinguishing systems. General Requirements for project
design, installation and utilization. Vietnam Construction standards, volumes 1, 2 & 3.

Particularly about fire fighting and preventing, the project owner had submited a separate
report on project general design fire fighting and preventing plan to Agency on Fire
Protection and Fire Fighting - Ministry of Security.




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Section        2.             PROJECT DESCRIPTION

2.1     PLANT LAYOUT [1]

The Ca Mau 2 Power Plant is located in the Integrated Gas – Power – Fertilizer (IGPF) in
Khanh An commune, U Minh District, Ca Mau province, which is 9 kilometer far from Ca Mau
City to the Northwest.

The Ca Mau Power Plant 2 is a combined cycle power plant (CPP), which uses natural gas
for input fuel and has a capacity of 750 MW.

In combined cycle power plant, all major facilities are standardized and manufactured in
separate modules in order to minimise the on-site construction and fabrication costs.
Therefore, the arrangement of these facilities of the plant is also based on a number of
standard designs and module configurations. The plant overall layout arrangement is
designed in accordance with these following factors:
    • Standardized technology of the CPP
    • Design, technique and safety criteria and standards
    • Geological and topographical characteristics
    • Tie-in with the power network
    • Internal traffic
    • Fire and Explosion Prevention
    • Good management of shared facilities in the IGPF
    • Good management of the working environment in the IGPF

The diagram of plant layout arrangement of Ca Mau 2 power plant is presented in Figure
2.1.


2.2     THE POWER PLANT

2.2.1 Overview

The Ca Mau 2 power plant has a capacity of 750 MW with the total area of ~ 10 hectares.

The main fuel for the plant is natural gas produced at Block PM3 in Southwest Vietnam Sea.
The stand-by fuel (will be used if there is emergency in gas supply) is Diesel Oil (DO), which
are stored in two (2 oil tanks with capacity of) 5,000m3/tank.

2.2.2   Power Generation Process




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The CPP is a multi-saft configuration comprising of 2 gas turbines (GT) of F generation, 2
heat recovery steam generators (HRSG), 1 steam turbine (ST) and following generators.




                                                                      Input
                                                                      System
           HRSG

           Diffuser


  Gas Turbine




                                                                                                Electric and
                                                                                                Control
                                                                                                Container

                                                 Generator
                                                                                   Generator Lead


                Figure 2.2        MODEL OF COMBINED CYCLE POWER PLANT
The principal power generation process of the CPP is summarised as follow (Figure 2.3):
Natural gas from distribution centre is heated (or DO from storage tanks) and fed into the
combustion chambers of 2 gas turbines. In these chambers, thermal energy resulted from
gas firing is converted into electrical energy. Exhaust from 2 gas turbines is subsequently
routed to 2 HRSG. High-pressure steam from HRSG is directed to steam turbine (ST) and
generator to produce electricity.

                                                      ST x 1
                                 HRSG                 260 MW x 1


                                              Steam

                                                                                   Condensation
        Exhaust from GT




GT x 2                    Fuel
250 MW x 2

        Figure 2.3        POWER GENERATION PROCESS DIAGRAM OF THE PLANT


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a) Gas Turbine – Generator Unit

The CPP will utilize the gas turbines of F-Generation, model V94.3A, which is manufactured
by Siemens (Germany). The gas turbine V94.3A has a nominal rating of 260 MW (ISO
Standard). The following generator is 165-350 MVA, 50 Hz, and designed in compliance with
ANSI and IEC standards.

The operating principle of the GT unit is summarised below:

Compressors via intake air filter feed air for combustion in. After compressed, air is supplied
to the combustion chamber where the gas or oil fuel is burned. Heat generated from fuel
combustion process is converted into force rotating gas turbine compressors and
generators.

Each gas turbine unit comprises of compressor, gas turbine, cooling system and auxiliaries.

    •   The compressor consists of 15 blade stages with a pressure ratio of 17, and provide
        compressed air for fuel combustion process and turbine cooling;
    •   The gas turbine has 4 stationaries and having blades made of high temperature
        alloy. Blades of the first three rows are specially coated for protection against high
        temperature corrosion. The combustion chamber is annular type and has 24 HR3
        burners, which is capable to fire both gaseous and liquid fuels. The HR3 burner is
        also low-NOx generation and minimizes the CO emission on account of the pre-mix
        and the stable and ultra-high efficient firing process.
    •   The cooling system use compressed air to cool the rotor and blades, without the
        need for other external cooling. The cooling air for the turbine is extracted from
        appropriate compressor stages, as each blade row requires cooling air at different
        pressure;
    •   Auxiliary systems: control and measurement system (monitoring rotation speed,
        temperature,..), mechanical protection system (safety blow off, hydraulic valve), liquid
        fuel auxiliary system (diffuser, premix, purging water,...), lube oil system, air-filter
        house, silencer, fire fighting system (detector, alarm, fire fighting,...), and etc.



b) Heat Recovery Steam Generator

The HRSG is the important faction of the power plant, which is responsible for transferring
heat from gas cycle to steam cycle. In HRSG, heat of exhaust gas from gas turbine is
recovered to produce superheated steam from feeding water. HRSGs of Ca Mau 2 power
plant have a design of 3 pressure stages: the high (HP), the intermediate (IP) and the low
(LP) pressures. Steams from them are supplied to the appropriate stages of the Steam
Turbine (ST) to generate electricity.




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High-pressure Heat Recovery System




Feed water from HP feed pump is conducted to the HP section of HRSG. Exhaust gas from
GT is fed into the system beginning from the superheated. Superheated steam from the
super heater is directed to the HP Turbine. Exhaust from HP economizer is then delivered to
the inlet of IP super heater of the IP Heat Recovery system.

Intermediate-pressure Heat Recovery System




Similar to the HP process, feed water is heated in the IP economizer and steam is generated
in the IP evaporator. Subsequently, the saturated IP steam is routed via the IP super heater
and mixed with the exhaust steam “cool reheated steam” of HP Turbine. The mixed steam is
the entering the reheat section for being reheated up to saturated state. This mixed steam,
called “hot reheated steam”, is then supplied to the IP Turbine.

Low-pressure Heat Recovery System

Feed water, extracted from intermediate stage of IP feed water pump, will be heated in the
LP economizer before entering the LP drum. Similar to the HP and IP process, steam is
generated in the LP evaporator and may be superheated in superheated LP set subjecting to
the design requirements of ST manufacturer. LP superheated steam is supplied to the LP
Turbine together with exhaust from IP Turbine.


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Exhaust in each HRSG after passing through heat exchangers will be emitted to the
atmosphere via separate stacks with minimum height of 40 meters.
Data on emissions of each HRSG is presented in Table 2.1.
       Table 2.1         EMISSION DATA OF HEAT RECOVERY STEAM GENERATOR

             Description                        Unit           Gas Firing                 DO Firing
Number of Stack                                             1 Stack / 1 HRSG          1 Stack / 1 HRSG
Stack diameter                                   m                 6.5                       6.5
Stack height                                     m                  40                       40
Exhaust velocity                                m/s                 20                        21
Exhaust flow                                    m3/s               674                       736
Temperature at stack outlet                      ºC                 97                       138
Emission rate (approximate):
N2                                              %                  72.86                     69.86
O2                                              %                  11.57                     10.21
CO2 and SO2                                     %                  4.015                     5.717
H2O                                             %                  10.86                     13.37
NOx                                           mg/Nm3                51.3                     149.8
SOx                                           mg/Nm3                0.83                    180-277*

Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005
Note: * according to the Sulfur content of 0.3-0.5% wt.

c) Steam Turbine – Generator Unit
The steam turbine has three stationaries: high pressure (HP), intermediate pressure (IP) and
low pressure (LP). Auxiliary systems are: auxiliary steam system, lube oil system, hydraulic
control system, and steam valves. The generator is designed following IEC and ANSI
standards, rating of 165-350 MVA and frequency of 50Hz.
HP steam from HRSG is supplied to the HP stationary of steam turbine via the main stop
valve and control valve. From the outlet of HP Turbine, the cold reheated steam is mixed
with IP steam and then being superheated in IP super heater. The hot reheated steam is
entering the IP Turbine via a stop valve and control valve. In LP Turbine, LP steam from LP
section of HRSG is fed through a stop valve and control valve. The steam will depressurize
among blade rows and rotate the generator. After the turbine, the steam is routed to the
condenser surface-cooled by water.
Separate HP, IP and LP steam by-pass stations will be equipped to accomplish high
operational flexibility in start-up, halt and other abnormal operation. The by-pass system is
designed with 100% of maximum steam capacity.
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2.2.3 Plant Auxiliary System
2.2.3.1 Share facilities for CM1 and CM2 Power plant
Share facilities for CM1 and CM2 Power plant are listed below:
1. Supplementary Cooling water (CW): CW intake canal is enough for 2 power plants.
   2X100% CW supply pumps for each plant.
2. Water supply:
    Demineral water treatment: Treatment process is located at CM1 power plant with
    capacity of 3X50% for 2 plants (standby equipment) and treated water is stored in 02
    tanks with capacity of 800m3 at CM1 power plant and in 01 tank of 800m3 capacity at
    CM2 power plant;
    Domestic water: Domestic water for both plants is treated at CM1 power plant, treated
    water is stored in tank of 150m3 and then pump to storage tank at CM1 power plant and
    is used for both plants;
    Service water: is pumped from CM1 power plant to upper storage tank of CM2 power
    plant;
    Fire fighting water supply: is supplied from fire fighting system of CM1 power plant.
3. Wastewater treatment: capacity of CM1 wastewater treatment system (WTS) is
   increased for both plants, wastewater of CM2 power plant is pumped to WTS of CM1
   power plant to treat and discharge together with CM1 power plant.
4. Cl, HCl system: located at CM1 power plant and supply for both plants
5. pH control system for supplementary cooling water: located at CM1 power plant.
6. DO fuel supply: install two oil storage tanks of 2x5000 m3 at CM2 power plant, two of
   which have pipeline to oil jetty and connect with 2 oil storage tanks of CM1 power plant.
7. Warehouse: is shared for both plants and located at CM1 power plant.
8. Repair workshop: is built at CM1 power plant.
9. Specialized tool: big specialized tool is shared for both plants.

2.2.3.2 Cooling water System
Similar to the CM1 Power Plant, the cooling system of Ca Mau 2 power plant is closed
circulation type. Excess heat from the main condenser and the auxiliary cooling system will
be transferred into the cooling water, which will be cooled at cooling towers. The
recirculation process of cooling water is maintained by the main cooling pumps.
Any water loss in the closed circuit system – mainly due to evaporation and tower blowing down-
will be compensated by the additional water supply system with maximum flow rate
Vmax=3.600m3/h. The cooling water system is presented in Figure 2.4.
a) Main Cooling Water System
The main cooling water system of Ca Mau 2 power plant consists of:
   • The main cooling water pump station
   • The main cooling water pipelines
The main cooling water pump station is installed at water storage tank of the cooling water
tower. Water is pumped from storage tank to the condenser and heat exchangers of the
additional cooling system via two main cooling pumps. Upstream of the condenser, a
pipeline cleaning system is provided in order to protect against block-ups and loss of heat
conductivity.
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Main cooling water pumps have the following design parameters:

    •    Total nominal flow rate: 10 m3/s
    •    Cooling water pump configurations: 2 x 50%
    •    Flow rate of each pump: 5 m3/s
    •    Water pipeline diameter: 2,200 mm

Forced cooling water towers (equipped with blowers), with shared chamber configuration,
are selected for the Ca Mau 2 power plant.

Design data of the cooling tower:
   • Number of chamber: 8
   • Circulation flow: 35,835 m3/h
   • Hot water temperature (intake): 45°C
   • Cool water temperature (outlet): 35°C
   • Wet bulb temperature: 25°C
   • Relative humidity: 85.17 % (according to wet chamber temperature)
   • Drift loss (% of circulation): 0.0005 %
   • Evaporation loss (designed) 1.61 %
   • Design wind pressure (for construction): 1.00 kN/m²
   • Atmospheric pressure: 1,013 mbar

The operating principle of forced cooling tower is summarized as follows: Air flow generated
from blower will be entering from the tower bottom, traveling upward and passing through
heat exchanging panels. Water will be sprayed from the tower top, moving downward and
exchanging heat with air flow, mainly due to the evaporation process. Heat exchanging
panels installed at tower middle will improve the heat transfer efficiency between the water
and the air flow. Resulting from the heat exchange with wind, water entering the tower
having a temperature of 45oC will be cooled down to 35oC at the tower outlet in normal
operation. When tail gas incident occurs, inlet temperature is 52.3oC and outlet one of about
40oC.

b) Additional Cooling Water Supply System

Additional supply water for the main cooling water system is taken from the Cai Tau River
through a canal system and pumping station shared with Ca Mau 1 power plant. The intake
canal and storage basin of the additional water pumping station is designed with the criteria
presented in Table 2.2.

        Table 2.2   DESIGN PARAMETERS OF ADDITIONAL COOLING WATER SYSTEM

                         Parameters                                                    Value
Design flow (m3/s)                                                                        2
Water velocity in canal/pumping basin (m/s)                                          0.3 – 0.5
Bottom canal elevation (m)                                                             - 3.40
Canal area (m2)                                                                         > 6
Canal width (m)                                                                           4
Minimum water level/canal depth in low tide (m)                                    - 0.90 / 2.50
Minimum depth/ intake width (m)                                                       - 4.0 / 6
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005

In order to prevent debris coming along with water, screenings will be provided at the
transition place at the intake gates of the canal and the pumping basin. In front of the
screenings, there are installed with blocking panel to isolate the canal during maintenance.
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In order to prevent oil penetrating from the river and/or the adjacent fuel import jetty, these
blocking panels will be positioned in such the way that the fixed upper part of the panel will
block the oil.

At the additional water supply pumping station at the end of the canal, screenings will retain
debris before water is pumped to the cooling water basin (circulation).

Because the water quality of the Cai Tau River is acidified in the rainy season, it is required
to treat the cooling water used for supplying and cooling by:

    •   Injection of NaOH solution to control pH
    •   Injection of H2SO4 solution and anti-scaling agent
    •   Clorination


c) River Water pH Control System

The river water pH control system comprises of 2 dosing pumps, 2 caustic soda (NaOH)
tanks, connecting pipes, valves and control equipment.

During the rainy season (from end of May to September), when Cai Tau River water has a
pH lower than 5.5 (about 3.0 – 4.0), the intake water will be injected with NaOH solution
(caustic soda) to raise the pH to the safety level of 5.5-8.0.

The caustic soda solution (30% or 50%, or similar to water treatment solution) will be stored
in 2 (or 3) tanks. The capacity of these tanks will adequately supply the NaOH 50% solution
in two weeks. The tanks will be constructed beside the clorination facility (outdoor) and the
dosing pumps are roofed.

The NaOH solution will be injected into the supply pipeline by the dosing pump, in which the
solution will be diluted by water to yield the final diluted solution. At the cooling water intake
gate, this solution will be dispersed via diffusers in order to create a good dispersion in the
canal.

With the water velocity in the canal of the addition cooling water system is 0.3-0.5 m/s (and
the canal length of 200m), there is more than 6 minutes for the NaOH solution to mix with
water before the cooling water flows to the pumping basin.

d) Sulfuric Acid and Anti-Scaling Injection System

The system consists of 2 acid dosing pumps. 1 sulfuric acid storage tank, 2 anti-scaling
agent dosing pump, 1 anti-scaling agent storage tank, connecting pipes, valves and control
equipment.

Sulfuric acid will be injected/sprayed into the cooling water basin to protect against scaling
and maintain the pH of water below 8.0, usage dose varies in range of 40 – 100 g of sulfuric
acid per a cubic metre of supply water. The sulfuric acid injection process will be monitored
by a pH meter. Sulfuric acid with concentration of 98% will be used.

The anti-scaling agent will be injected into cooling water for prevention of scaling/corrosion
at surface of heat exchangers.



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e) Chlorination System

The chlorination station will protect the cooling water systems of the power plant against the
development of aquatic organisms such as algae, mollusks, and etc. which can block heat
exchanging surfaces and reduce the operating efficiency of relevant systems and
equipment.

Active chlorine can be provided as free chlorine (Cl2) or hypochlorite solution. Available free
chlorine in the market has the liquidified gas form and is stored in high pressure tank.
Chlorine will be fed to the spraying system from storage tanks each has a capacity of 1
tonne.

The chlorination system includes 4 chlorination chambers, 4 chlorinators, 2 evaporator, 4
storage tanks, 1 chlorine-leak detector, connecting valves, control equipment, and protective
gears such as gas masks and compress air inhalation equipment.

f) Cooling Water Monitoring

At the water basin of the cooling tower, pH and conductivity will be continuously monitored.
Monitoring equipment will be installed in the on-site sampling panel.

In monitoring of the blow down water from cooling tower, the remaining chlorine will be
analyzed to control the chlorine content in discharged water.

2.2.3.3 Gas supply system for power plant

Fuel of the power plant is natural gas. Natural gas is routed via the pipeline from PM3 gas
field to the gas distribution station. At the gas distribution station, natural gas is pre-treated,
dried from water and other liquids, dust filtering, and pressurizing to 40-60 bar as technical
requirement of the power plant.

From the gas distribution station, natural gas is distributed by separate pipeline to the Ca
Mau 1 power plant 1 and Ca Mau 2 power plant. The gas received at the plant front-end is
dry and clean gas. Estimation of gas demand for the power plant is presented Table 2.3 and
gas characteristics are presented in Table 2.4.

               Table 2.3         ESTIMATION OF GAS DEMAND OF THE PLANT

        Operation time                     Unit           Gas from PM3 Field         Gas from Block B
  1-hour maximum                       Thousand m3              132.84                    146.32
 1-day average (20 hours)              Thousand m3             2,656.75                 2,926.45
 1-day maximum (24 hours)              Thousand m3             3,188.10                 3,511.74
 1-year
                  5000 hours           Thousand m3             664,186.86                731,612.18
                  5500 hours           Thousand m3             730,605.54                804,773.40
                  6000 hours           Thousand m3             797,024.23                877,934.62
                  6500 hours           Thousand m3             863,442.91                951,095.84
                  7000 hours           Thousand m3             929,861.60               1,024,257.06
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005




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          Table 2.4         INPUT GAS CHARACTERISTICS OF THE POWER PLANT

 No.             Characteristic                     Unit                Value                      Note
  1    Gas fraction                                                     1.000
                                                     o
  2    Temperature                                   C           20 above dew point              At 40 bar
  3    Pressure                                    Kpag             4000 – 6000                 40 – 60 bar
  4    Molar flow                                 Kmol/h              0 – 6206
  5    Mass flow                                   Kg/h              0 – 134630
  6    Z factor                                                   0.8162 – 0.8724
  7    Viscosity                                     cP           0.0127 – 0.0136
  8    Cp/Cv                                                        1.439 – 1.568
  9    Molar weight                                                    21.693
 10    Density                                     kg/m3            40.46 – 64.33
 11    Standard volume flow                        m3/h                 0.000
 12    Standard gas flow                           Nm3/h             0 – 146738
                                                    o
 13    Dew point temperature                         C               -8.8 ÷ -5.77
                                                    o
 14    Dew point temperature of                      C               9.47 – 9.86
       Hydrocarbon
  15   Water                                       mg/m3                 76.97
  16   C6 hydro                                    % mol                 0.0020
  17   Methane                                     % mol                 0.7795
  18   Ethane                                      % mol                 0.0678
  19   Propane                                     % mol                 0.0403
  20   i-Butane                                    % mol                 0.0118
  21   n-Butane                                    % mol                 0.0091
  22   i-Pentane                                   % mol                 0.0039
  23   n-Pentane                                   % mol                 0.0023
  24   H2O                                         % mol                 0.0001
  25   CO2                                         % mol                 0.0753
  26   N2                                          % mol                 0.0079
  27   High calorific value                        MJ/m3                  41.6
  28   Low calorific value                         MJ/m3                  37.7
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005

After the gas receiving point, an emergency stop valve will be installed. The fuel gas
distribution system includes dust and liquid separators, collectors, condensate collector,
metering equipment and the pre-heating system (if required).
a) Stop Valve (Emergency Valve)
Stop valve is installed behind the gas receiving point, which must be able to isolate the
whole gas distribution system of GTs in an emergency case. Stop valve must be remotely
operated with close and open functions are activated manually from the Center Control
Room.
b) Dust-Liquids Separator
Two dust-liquids separators (2x100%) will remove dust and liquids in the natural gas. Dust
and liquids will be separated by cyclones.
c) Gas Venting
It is not required to install a flare for the power plant because the excess gas will be flared at
the gas distribution station located at the South of the plant. The plant will be equipped with

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gas venting pipelines for the gas distribution system. These vents will be positioned safely
above the ground in order disperse emissions into the atmosphere.

d) Metering Station

The metering station will measure and log the gas quantity used by the power plant. The
pipeline metering system will measure the temperature and pressure independently, which
are used to convert the quantity of gas from actual pressure to standard pressure.

e) Dust filter

After each dust-liquids separator, 2 dust filters (2 x 100%) will be installed. The dust filter is
applied modern technology to remove dust, rust, and other solid contaminates from dry gas.

f) Pre-heating System

In case the gas turbine manufacturer requires gas temperature above 20oC greater than the
dew point, the use of pre-heating system is also required. The pre-heat of gas will prevent
the hydration, which can affect negatively to gas firing equipment.

When operating the combined cycle process, the pre-heating is indirectly undertaken by hot
water extracted from the IP economizer. The minimum gas temperature must be 20oC higher
than the dew point of water or hydrocarbons.

The gas distribution system is presented in Figure 2.5.

2.2.3.4 Fuel Diesel Oil System

When there is an interruption in gas supply, the plant will have to use fuel. However, the
plant will use DO having low sulfur content to reduce the SOx and dust emissions. Besides,
when operating, the plant will use DO for a few days only throughout the year.

The DO utilized for the power plant is the distillate oil meeting technical criteria of ASTM
No.2 standard.

 Table 2.5        CHARACTERISTICS OF DIESEL OIL (DO) USED FOR CAMAU 2 POWER
                                      PLANT

                                                              Value
 No.                 Properties                                                       Unit         Note
                                                      Min              Max
  1     Colour                                                                         -
  2     Density @ 15 °C                                                 876          kg/m3
  3     90% distillation temperature                                    338           °C
  4     Flash point                                    38                             °C
  5                                                                                              Maximum
                                                                                                allowable of
        Sulfur content                                                  0.5           %wt       TCVN 5689-
                                                                                                   2005 is
                                                                                                  0.25%kl
   6    Nitrogen                                                                      ppm
   7    Corrosion 3 h / @ 10°C                                         No.1             -
   8    Viscosity @ 40 °C                              1.9              4.1           cSt
   9    Freeze point                                                   - 6.0           °C
  10    Carbon residue of 10% distillate                               0.35           %wt
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                                                              Value
  11    Ash                                                            0.01            %
  12    Na + K                                                          0.5           ppm
  13    Total heavy metal
        -V                                                              0.5
                                                                                      ppm
        - Pb                                                            2.0
        - Ca                                                            10
  14    Water and residue                                               15           %vol
  15    Low calorific value                                            42.5          MJ/kg
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005

According to the calculated data for the maximum sulfur content of 0.5%, the concentration
of SO2 at stack top is about 277 mg/Nm3, still lower than the discharge standard for power
industry TCVN 7440-2005. However, when operating with DO, the Ca Mau 2 power plant will
still use DO having sulfur content lower than 0.5%.
The DO storage and distribution system of CM2 power plant consists of 2 storage tanks,
each of which has capacity of 5.000 m3, oil recovery basin, main oil pump system, auxiliary
pump system and oil pipelines. The two oil storage tanks are connected with the oil storage
facility of CM1 power plant. The estimated DO demand of the plant is presented in Table 2.6.
              Table 2.6         ESTIMATED DIESEL OIL DEMAND OF THE PLANT

           Operation time                              Unit                       Fuel quantity
 1-hour maximum                                       Tonne                          108.52
 1-day average (20 hours)                             Tonne                         2,170.48
 1-day maximum (24 hours)                             Tonne                         2,604.58
 7-day average                                        Tonne                        15,193.38
 7-day maximum                                        Tonne                        18,232.05
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005

Oil from storage tanks is delivered to gas turbines via the oil pumping system including
pumps; double filters, isolating valves, 1-way valves, pressure gauges, and pressure
switches behind and in front of the pump.

2.2.3.5 Potable Water System
For every demand of technical water of the plant, potable water will be supplied from the Ca
Mau Water Supply and Drainage Company to the plant front-end, and then directed to the
potable water tank. The Ca Mau 2 power plant will be water-connected with the Ca Mau 1
Power Plant. Potable water is supplied for following systems:
   • Dematerialized water
   • Domestic water/ service
   • Water for other purposes

List of potable water demand of the Ca Mau 2 power plant is presented in Table 2.7.

         Table 2.7         POTABLE WATER DEMAND OF CA MAU 2 POWER PLANT

                Description                            Unit                 Average demand
    Demineralized water                               m3/day                    665.98
    Domestic water                                    m3/day                     51.84
    Other purpose water                               m3/day                     51.84
    Total                                             M3/day                    769.66
Source: General Report of investment project for Ca Mau 2 Power Plant- volume 1- December, 2005

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2.2.3.6 Demineralized Water Supply System

The demineralized water system will be shared with the Ca Mau1 Power Plant. The
demineralization station will produce and supply demineralinized water to:

    •   Additional water for the condenser of steam turbine
    •   Additional water for closed circuit cooling facilities of the auxiliary cooling system
    •   Water for heat recovery systems
    •   Water for cleaning compressors
    •   Water for injection combustion chamber of gas turbine (for low-NOx burners when
        using DO)
    •   Water for chemical injection systems
    •   Water for filling up the HRSG

Capacity of the additional demineralized water system for Ca Mau 2 power plant is 25 m3/h,
the treatment process of system includes 2 stages: Reverse Osmosis (RO) and Ion
Exchange.

Water before entering the RO will be added anti-scaling agent and dechlorination to avoid
membrane scaling and oxidizing.

2.2.3.7 Wastewater Treatment System

In order to share facilities for 2 power plants for economizing investment expenditure,
industrial wastewater treatment system will be used for both plants and located at Ca Mau 1
power plant – with enough capacity for both CM1 and CM2 power plant. The share
wastewater treatment system consists of storage basins made of waterproof concrete.

    •   1 oil-water separating basin
    •   1 wastewater storage basin
    •   1 neutralization basin
    •   Pumps, pipelines, valves and control equipment.
Industrial wastewater of the CM2 power plant will be pumped to the share wastewater
treatment system located in the CM1 power plant through separated pipeline system.
Treated water met environmental standards will be discharged at the same industrial
discharged location of CM1 power plant to the Cai Tau river. Detailed descriptions of the
wastewater treatment system will be presented in Section 6 of this report.

2.2.3.8 Electricity System

a) 220 kV Switchyard
The voltage of 220 kV is selected for Ca Mau 2 Power Plant to tie-in with the power network
of EVN. The outdoor 200 kV switchyard is designed with 1-breaker configuration. The layout
of the switchyard is presented in Figure 2.6.
Ca Mau 2 Power Plant will be connected with the national grid at 200kV-voltage via the
220kV transformer of Ca Mau 1 Power Plant. Additional transmission lines for Ca Mau 2
Power Plant are:
   • A single 220 kV line Ca Mau – Bac Lieu
   • A double 220 kV line Ca Mau - Rach Gia
   • A single 220 kV line to Ca Mau Transformer Station
   • A single 220 kV line Ca Mau – Soc Trang
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b) Self-Power System

The power for the whole plant own usage is rooted from 2 self-transformers installed at the
breaker between two gas turbines. The self-power consumption rate makes up of 2-3% of
the generation capacity, equivalent 22.5 MW.

The self-power system of the plants includes:
      •   The AC system which comprises a mid-voltage (6.6kV supplied for engine and
          machine > 200kW such as pumps) and a low-voltage system (0.4 kV supplied for
          machine and engine < 200 kW and control center);
      •   Main self-transformers (2 x 23 MVA), magnetic-activated transformers of gas turbines
          and steam turbine and unit-self usage (3 x 1.6 MVA), HRSG transformers (2 x 2
          MVA), and plant-shared transformers (2 x 2 MVA);
      •   The emergency diesel generator of 400 kV with capacity of 750 kW;
      •   The DC system for control and supervision and supplied for DC engines. Tentatively,
          there are 2 voltage levels which are 220V (supplied for engines, controls, emergency
          lightning, and protection switches) and 48 V (supplied for communication system,
          electronics, fire alarms and computers); and
      •   The Uninterruptible Power Supply (UPS) system

2.2.3.9 List of used Chemicals in power plant

Major chemicals listed in Table 2.8 will be used for the whole operation phase of the power
plant.
               Table 2.8 LISTS OF USED CHEMICALS OF THE POWER PLANT

  No               Description                        Purpose                Storage              Rate
                                                                             Volume
                                               For Boiler
 1         Phosphate (5% solution)                  Boiler                   1.0 m3               30l/h
 2         Hydrazin (1-2% solution)                 Boiler                   0.75 m3              16l/h
 3         Ammonia (1-2% solution)                  Boiler                   0.75 m3
                                          For Cooling System
                                                                                1
 4         Chlorine                          Treating cooling water         ton/contai      4 times/day
                                                                               ner
                                                                                            40-100g/m3
 5         Sulfuric acid (98%)               pH control                      1x50m3
                                                                                             add 70l/h.
                                             Protecting against
 6         Anti-scaling agent                                                 1x5m3               10l/h
                                             scaling and corrosion
                                                                                     3
                                                                             3x60m
 7         Sodium hydroxide, 30-50%          pH control                                         5-8.5m3/h
                                                                             2x60m3
                                             Demineralizing &
 8         Hydro Chloride acid                                              2 X 25m3             8m3/h
                                             Neutralizing
                                             Demineralizing &
 9         Caustic soda                                                     2 X 15m3             12m3/h
                                             Neutralizing
 10        Chloride iron                     Neutralizing                   2 X 15m3             6m3/h




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2.2.3.10 Fire and Explosion Fighting System
The plant is designed for operating safely to people and equipment. In order to achieve this
target, equipments are arranged properly so that the risks of fire and explosion are
minimized. The system is designed in compliance with American National Fire Fighting
Association (NFPA) standards.
Areas having risks in the plant are gas distribution station, storage tanks area, transformer
area, lube oil tank, gas turbine combustion chamber and machine house
The plant will be equipped with the following fight fighting systems:
   • Fire detector and alarm
   • Automatic Sprinkler
   • Stationary Foam System
   • Mobile Foam System
   • Tank water-cooler
   • Firewater posts
   • Fire extinguishers
The fire and explosion fighting system is designed in compliance with Vietnamese standards
and NFFA as following:

    •   Maximum water pressure: 14 bar
    •   Fire water flow: 12.0 litres/m2/min
    •   Deluging rate: 10.0 litres/m2/min
    •   Foam rate is 4.1 litres/m2/min to protect for DO storage tank
    •   Outside of the dyke surrounding oil storage area, there will be installed foam hoses
        with flow rate about190 liters/min.
The Ca Mau 2 power plant will share the fire-water pumping station with the Ca Mau 1
Power Plant. Water supply for the fire water system is from potable water storage tanks of 2
x 2000m3. Only the foam system will be newly built.

Firewater posts are equipped along the distribution system with the interval of 80m. Tools and
accessories are provided in box at each post, Portable fire extinguishers are properly placed
inside machine houses and buildings of the plant for fire preventing and fighting demand.
    •   Indoor fire-water posts are placed at turbine house, cooling water pumping station,
        water treatment station, and control room, gas distribution station and oil pumping
        station.
    •   Deluging systems are placed at hydraulic oil/lube oil system area, transformer area
        and lube oil storage area
    •   Outdoor fire fighting water posts are placed at gas turbine area, HRSG area .
    •   CO2 systems are placed at electric instrument room and central control room.
    •   Foam systems are placed at oil tank area and oil pumping station

Smoke detectors are equipped in electrical machine rooms. Heat detectors are installed in
the lube oil system, the transformer area, and the tank area. Gas leaking detectors are
installed at the gas distribution station and the gas turbine area.




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2.2.3.11 Communication System

The plant communication system has the following functions:
   • Communicate among the plant, the national and the regional control centers
   • Communicate among controls and supervisions of the plant

The communication system of Ca Mau 2 Power Plant includes:

    •   The internal PABX directory system
    •   Optic cables for data transferring between CM1 and CM2 Power Plant
    •   Direct telephone line to the National Power Control Centre (A0), the Southern Power
        Control Centre, O Mon Power Plant and 220KV transformer stations of Rach Gia,
        Bac Lieu and Ca Mau.
    •   Data channel for connecting the computer network of the plant to the computer
        network of EVN.

According to the project schedule, the Ca Mau 1 Power Plant will come into operation firstly.
Therefore, the Ca Mau 1 Power Plant will host the communication and data transferring for
both the plants.

2.3     CONSTRUCTION PHASE
2.3.1 Site Preparatory Works

The construction site is prepared and leveled to +1.97m (at the boundary) and +2.84m (at
centre) by geotextiling/vacuum pumping and geotextiling/consolidating. The site has surface
loads of 2 – 8 tonne/m2 (depending on technical facilities) and a slope of 0.5 – 1.1% for
drainage.

2.3.2 Plant Construction

As designed, the Ca Mau 2 power plant will share some constructions with the Ca Mau 1
power plant such as the administration office, reparation house, storage house; … Major
constructions of the Ca Mau 2 power plant will be newly built as follow.

2.3.2.1 Main Plant

The main plant consists of gas turbine and steam turbine houses. The turbine houses are
designed as 1-level with steel frame.

The drainage basin and the submersible drain pump are installed at the lowest point of the
house. The main plant is constructed on the reinforced concrete base, pile supported.
Another reinforced concrete base will be used for installation of turbines and generators.

Ventilation for the main machine house will be natural ventilation via openings on the roof
and wall. The venting fan at the top roof is equipped with the automatic gas detector for
detecting gas leakage inside the building. Fire fighting equipment includes indoor firewater
hose, automatic CO2 deluge system, CO2 and chemical fire extinguishers and emergency
exits.

a) Main Transformer




CPMB– RDCPSE-Final report                                                                       June, 2006
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b) Transformers, HRSG and Main Stack

These facilities are constructed on outdoor reinforced concretes supported with piles. Oil
collection basins are designed below transformers and pumps will be provided to pump out
the oil in emergency case. Discharged water is directed to the oil separation basin of the
wastewater treatment system. The supporting frame of the stack is steel and 40 meters high
for the main stack.

c) Control Unit

The central control unit comprises of main control room, server room, working room, DCS
room, staff room, toilets, switch room and battery room.

The control unit is also equipped with the fire fighting equipment, which are firewater hose,
automatic CO2 deluge system, CO2 fire extinguishers and emergency exit and staircase.

d) Fuel Storage
The fuel storage includes 2 x 5.000 m3 oil tanks made by steel plates. All solders are
inspected by sonic waves. Surrounding the oil tanks, earth embankment covered by
waterproof concrete is constructed to avoid oil spill. The tank site is steeped and equipped
with storm water/oily water channel directing to the oil separation basin before conduct to
discharged system.

2.3.2.2 Wastewater Treatment System
The Wastewater treatment unit comprises of these following facilities/areas:
   • Demineralized water
   • Potable water
   • Chemical storage
   • Wastewater treatment
   • Electricity
   • Toilets
   • Labs
   • Working quarter
   • Basin and tank area

Besides water treatment unit, tank area, the Wastewater treatment works include:
   • Wastewater basin
   • Neutralization basin
   • Treated water basin
   • Oil separation basin

2.3.2.3 Cooling Water System

New-built system will be:
  • The main cooling water pump station
  • The main chlorination system for cooling water

The main cooling water pump station has steel frame design with area of 14 x 17 m,
comprising pumps, pipelines and accessories. All buildings above the base (floor and wall)
are waterproof concrete and pile supported. The whole construction is protected against
corrosion and has a metal roof without heat resistance cover.
2.3.2.4 Switchyard
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The 200kV switchyard of Ca Mau 2 Power Plant is tied-in with the extension of Ca Mau 1
Power Plant switchyard in order to connect to the power grid easily. Gates, bars and carriers
are made of steel coated with zinc by the hot dipping method, which are manufactured in the
warehouse and fabricated on site. These structures will be joined by bolts, which are
produced in compliance with Vietnamese Standard TCVN 102–73 and TCVN 62–73, and
tested before exported. All incoming and outgoing lines of the switchyard will be installed
inside the concrete canal. A safety mesh fence with the height of 1.8m will be implemented
around the switchyard.

2.3.2.5 Road system

The road system consists of domestic roads and interconnecting roads to traffic way outside
the plant. The domestic roads are designed so that the transportation among facilities is the
most convenient and shortest. Traffic ways outside the plant are expected to be incorporated
into the Ca Mau integrated gas- power – fertilizer area.

    •   Road for heavy machine transportation, 9 – 10m width;
    •   Road for 40-tonne lorry, 8m width;
    •   Road for light transportation, 4m width;
    •   Road for pedestrian, 1.5m width;
    •   Parking area
Buildings and areas are arranged in an appropriate distance, and tree lanes are provided
among them to minimize dust and noise and to enhance shadowness. Roads will be
constructed properly to each area type and made of reinforced concrete, configured to
include 3 layers: rocks at the bottom, macadam in the middle, and concrete/asphalt layer on
the top.

2.4     PROJECT DISCHARGE SOURCES
2.4.1 Emissions
In normal operation, the power plant will use gas as fuel source. This is a clean fuel and the
pollutants are only CO and NOx; SOx is almost none. When the plant uses DO for fuel,
major pollutants are CO, NOx, SOx and dust. Load (calculated for 1 stack) is 674m3/s (with
natural gas) and 736 m3/s (with DO). The EPC contractor will ensure emission rates always
complying Vietnamese discharge standards.

2.4.2 Effluents
Effluents of the plant are categorized as regular and non-regular effluents. Loads of these
effluents are detailed in Section 4.

2.4.3 Solid wastes
Solid wastes of the plant can be separated as industrial and domestic wastes:
    •   Industrial waste: Solid industrial wastes include packaging, oily rags, and sludge from
        water treatment. These waters are categorized for reuses. Disposal fraction will be
        collected and transferred to the landfill, or contracted with the provincial water supply
        and urban sanitation company for disposal.
    •   Domestic waste: Domestic wastes include garbage from living quarters, public areas,
        canteens and sludge from septic basins.
2.5     INVESTMENT FOR ENVIRONMENTAL PROTECTION
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During implementation, project owner always estimates a part of budget for environmental
protection works including:
    - During the construction, installation and commissioning phases of the plant: budget for
       the environmental protection works includes in EPC contract of the power plant. All
       treatment system will be completed in the commissioning phase.
    - In the operation phase: expenditure for the environmental protection works includes
       into operation cost of the power plant.

In practical, project owner has paid much attention to environmental protection issues even
from feasibility study phase and technical design. All necessary equipment to mitigate
environmental impacts have been invested such as safety system; Fire fighting and
prevention equipments, wastewater treatment system, and solid waste collection and
treatment system…

Due to CM2 power plant is one part of Ca Mau Power plant complex, so some facilities in
which environmental protection ones will also be shared for both plants such as: Fire fighting
and prevention system, laboratory…Environmental protection facilities separately installed
for CM2 power plant are shown in Table 2.9.

  Table 2.9 ENVIRONMENTAL PROTECTION FACILITIES OF CAMAU 2 POWER PLANT


  No                       Facilities                                           Note
   1     Waste water collection and treatment Belongs to invest budget of WTS for
         system (WTS)                         both CM1 & CM2 PP
   2     Valves and spare parts supplied fire Belongs to budget for share Fire fighting
         fighting water for CM2 PP.           and prevention system of both plants.
   3     Equipments for air emission monitoring Belongs to budget for stack complex
         at top of main stack.
   4     Solid waste collection and treatment              Will sign contract with Ca Mau Water
                                                           supply and urban sanitation following by
                                                           current price.

In the operation phase, the plant will have HSE staff. Especially, to ensure safety for plant
operation activities, all employees working in the plant will be trained in safety and
environmental protection issues. These training courses will concentrate on individual
responsibilities for each worker during safety and environmental protection maintain process
at working place of labours and its vicinity area.

Environmental protection works include expenditures for planting green tree and
establishment green belt at the plant boundary. This expenditure is included in budget of
EPC contract.

During the operation phase, project owner will strictly comply with the Government Decree
No 67/2003/NĐ-CP on the environmental protection fee for wastewater.




2.6     PROJECT SCHEDULE
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 Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)           28



 Major milestones of the project/power plant schedule are presented in Table 2.10.

                 TABLE 2.10        SCHEDULE OF CA MAU 1 & 2 POWER PLANTS

                                             CM1 Power Plant                        CM2 Power Plant
No
                Work                Duration                                Duration
 .                                                  Start        End                       Start       End
                                    (month)                                 (month)
     Tender and Bidding for
1                                                                                        01/2006
     EPC Contractor
2    Award EPC Contract                 <1        11/2005      11/2005         <1        02/2006     02/2006
     Implement EPC
                                        25        11/2005      12/2007         25        02/2006     03/2008
     Contract
     Site Preparation                   24        03/2005      03/2007          6        12/2006     06/2007
     Construction
                                        17        03/2006      08/2007         19        04/2006     11/2007
     Equipment installation
3    Open cycle operation               4        03/2007       07/2007
     Combine cycle
                                        4         08/2007      12/2007          3        11/2007     02/2008
     Commissioning
     Plant temporary
                                        1         12/2007      12/2007          1        03/2008     03/2008
     Licensing
     Plant Transfer                     1         12/2007      12/2007          1        03/2008     03/2008




 CPMB– RDCPSE-Final report                                                                         June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      29



                                           EXISTING
Section         3.                         ENVIRONMENT
                                           OF THE PROJECT
                                           AREA AND ITS
                                           VICINITY
The main content of this section is to describe the environmental characteristics of the
project area and its vicinity. The information will provide the basis for assessing potential
environmental impacts caused by project implementation as well as a basic reference for
future monitoring program.

Due to Ca Mau 2 power plant is located on the planned land for fertilizer plant, where the
Southern part is adjoined to Ca Mau 1 power plant at Khanh An Commune. The description
of existing environment is based on the field monitoring results and analysis samples
collected from 19 - 24/12/2005 and compared with the results in the EIA (Environmental
Impact Assessment) report of Ca Mau 1 power plant in 2002.

3.1 SCOPE OF PROJECT AREA
The Ca Mau 2 power plant is located in ward 3 & ward 1 of Khanh An Commune, U Minh
District. Its Northern part is bordered on Ca Mau 1 power plant, the Eastern one is closed to
Cai Tau confluence and the Western part is bordered on the Cai Tau K1 prison land (Figure
3.2). The project 's vicinity area in the space of 10km radius includes Tac Thu sluice, Cai
Tau residential area, K1 Prison, Khanh An's resettlement area, Vo Doi Specific Forest, U
Minh III and Tran Van Thoi forestry farms.

3.2     PHYSICAL ENVIRONMENT CHARACTERISTICS
3.2.1 Climate characteristic [2]

Meteorological data of the project area is referred to the survey data in many years at Ca
Mau Meteorological Station, located about 12.5 km far from the project area in the
Southwest direction.

1. Temperature

According to the statistical data during 1980 - 2004 at Ca Mau Meteorological Station, the
annual average temperature is high (27.2oC). The variation ranges from 25.6 to 28.5oC. In
the hottest month (April), the average temperature is from 27.7 to 29.8oC, and the variation
is from 24.8 - 27.2oC in the coldest month (January). The temperature difference among
months within a year is about 2.9 - 3.4oC. The daily highest different in the dry season is
about 7-8oC, and the lowest in the rainy season is about 6 - 7oC. The absolute highest
temperature is 37.8oC; the absolute lowest one is 16.20C and this remains in a short period
of day. The monthly average temperature in the duration of 1980 - 2002 is showed in Table
3.1.

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         Table 3.1 STATISTICAL MONTHLY AVERAGE METEOROLOGICAL DATA
                          AT CA MAU STATION (1980 - 2004)
Month                I      II    III    IV      V     VI     VII    VIII    IX     X       XI     XII     Year
               o
Temperature ( C) 25.6     26.1   27.4   28.5   28.3   27.7   27.5   27.3    27.1   26.9    26.8    25.9    27.2

Humidity (%)       78.6   78.1   76.5   77.1   82.1   85.0   85.1   86.4    86.8   87.0    83.7    80.2    82.2

Pressure (mb)      1012.2 1011.6 1010.5 1009.1 1008.7 1008.1 1008.2 1008.4 1009.0 1009.5 1010.2 1011.6 1009.8

Sunshine hours   226.1 212.7 253.2 226.4 168.8 145.5 152.5 137.9 140.5             137.8   169.9   197.4 2168.6
*
Solar radiation
          2
(Kcalo/cm ) **
                  452 470 530 459 388 364 372 362 370                              359     375     373     406
Source: Southern Region Hydrometeorological center, 2005
Note:    (*)    from 1996 – 2004;                (**)    from 1996 – 2001

The statistical data shows that the monthly average temperature in the duration of 1980 -
2004 at Ca Mau is relatively high and stable.
2. Humidity
Humidity of the study area is closely related to rain and wind regime. The average relative
humidity is quite high (82.2%). The relative humidity peaks at 87% in October (rainy season)
and the lowest one is at 76.5% in March (dry season). The observed absolute lowest
humidity is 40% in 1958. In the rainny season lasting from May to November, average
humidity is about 82 - 87%. In the dry season, except December has, average humidity more
than 80%, almost other months (from January to April), average humidity is lower than 80%
(Table 3.1). The difference of humidity between the wettest month and the driest month is
ranged from 9% to 11%.
The highest relative humidity in the duration of 1980 - 2004 is 90% (October, 1980), the
lowest one is 71% (March, 1998), the annual average one is 82.2%.
3. Air Pressure
Based on the statistical data from 1980 to 2004, the annual average pressure was 1,009.8
mbar (Table 3.1), the variation is not much between months. The differences of air pressure
among regions are not much. Therefore, it makes the balance and stability of the
meteorological conditions in this area.
4. Sunshine
Ca Mau is located in the area where the average sunshine hours are quite high, the total
annual average sunshine hours are 2,168.8 with about 6.8 - 7.5 hours/day. In the dry
season, the average sunshine hours are 7-8 hours/day, equivalent to 219 hours/month.
March usually has the highest average sunshine hours of about 253 hours/month, whereas
October has the lowest one (137.8 hours/month) (Table 3.1).
5. Solar radiation
Solar radiation in the project area is rather high and stable with the average annual value of
406 Kcalo/cm2.
6. Evaporation
The annual average evaporation in Ca Mau is rather high about 973 mm (Piche). In dry
season, due to high sunshine and low humidity, the evaporation is high and reaches the
peak in March (124 mm). The deficiency of rainfall in comparison with maximum evaporation
occurs in February (11 times higher than one in Ca Mau Station) (Table 3.2). In rainy
season, the evaporation significantly decreases in comparison with the dry season. The
lowest evaporation is only 52mm in October.

CPMB– RDCPSE-Final report                                                                           June, 2006
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  Table 3.2 COMPARISION BETWEEN THE AVERAGE EVAPORATION AND RAINFALL
                       IN THE DRY SEASON (1980-2004)
                                                               Month                                    Deficiency
Location       Characteristic                                                                  Total
                                       I            II           III      IV           XII                (mm)
            Evaporation (mm)         100           99           124      105           87       614
Ca Mau                                                                                                       383
            Rainfall (mm)             18            9            32       97           88       231
Source: Southern Region Hydro Meteorological Center, 2005

7. Rainfall
Annual rainfall
The study area has a very high annual rainfall (2,484 mm in Ca Mau). The average number
of rainy days in this area is quite high, approximately 163 - 171 days at Thoi Binh, 171 days
at U Minh and 167 days at Ca Mau. Annually, there is about 1 rainy day per 2 days.
Seasonal and monthly rainfall
Monsoon regime has brought 2 distinguished seasons: rainy season and dry season. In
general, the rainy season lasts 7 months from May to the end of November, which is the
same time with Southwest monsoon season. In this period, the percentage is about 82 -
91% in comparison with the annual rainfall. Dry season begins in December and ends in
April in next year. This period simultaneously occurs with Northeast monsoon season, which
has only 9 - 18% of total annual rainfall (Table 3.3). Especially, sometimes, rainy season
comes quite soon (1999), or very late (1998).
                  Table 3.3 ANNUAL AND SEASONAL RAINFALLS IN CA MAU

                   Annual Rainfall         Rainy season (V-XI)          Dry season (XII-IV)
   Station                                                                                              Notes
                       (mm)                X(mm)               (%)      X(mm)            (%)
   Ca Mau               2,484              2,222               89.5       262           10.5          1980-2004
   U Minh               2,471              2,025               82         446            18           1984-2001
   Thoi Binh            2,330              2,078               89         252            11           1984-2001
Source: Southern Region Hydro Meteorological Center, 2005

In the rainy season, the monthly average rainfall gradually increases from May (above
250mm and rainy days are higher than 11 - 15 days). The highest rainfall is observed from
July to October (higher than 300mm of rainfall and 19 - 23 rainy days). In November, the
average rainfall is decreased, in general it is only about 150mm with 10 - 12 rainy days.
Variation of monthly rainfall is very high, particularly at the beginning and at the end of rainy
season. There are about 10-25% of the observed years in which the annual rainfall was 1.5
times higher than ones in the same period (Table 3.4).
   Table 3.4 THE MAXIMUM MONTHLY RAINFALL (MM) IN CA MAU IN COMPARISON
                 WITH THE STATISTICAL MEAN VALUES (1960-2004)
Characteristic                                                       Month
                      I     II       III     IV           V       VI    VII     VIII    IX      X       XI        XII
     Max             116    81       173     446         556     594 601        589    702     749     374        309
   Average           18      9       32      97          290     306 330        343    337     332     170        88
    P(%)             13     10       26      10          10       3      3      13       3      3      16         10
Source: Southern Region Hydro Meteorological Center, 2005
 Notes: Max     : highest monthly rainfall (mm)
        Average : average monthly rainfall over the years (mm)
        P%      : percentage (%) of year number having higher value of monthly rainfall in comparison with the
average ones



CPMB– RDCPSE-Final report                                                                                June, 2006
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In the dry season, except the first and the last months (December and April), the rainfall is
about 50 mm with 5 - 10 rainy days. The monthly rainfall in the middle of this period is
approximately 10 mm with 1 - 2 rainy days (Table 3.5). Significant deficiency of fresh water
usually happens in this period.
               Table 3.5 THE AVERAGE RAINFALL (MM) IN CA MAU STATION

              Year                                   Month (mm)
   Station    (mm)
                                                                                                        Notes
                       I     II    III   IV     V     VI    VII   VIII   IX     X     XI        XII
 Ca Mau        2352   18     9     32    97    290   306    330   343    337   332    170       88    1960-2004
 Thoi Binh     2330   14    27     31    133   272   335    328   331    322   323    167       46    1984-2001
 U Minh      2471   20    25   64    167    236   286    355      348    340   304    156       45    1984-2001
Source: Southern Region Hydro Meteorological Center, 2005

In general, the project site is located in the area where the annual average rainfall is very
high. However, the rain distribution is unequal within a year, therefore it causes water
redundancy in the rainy season and water deficiency in the dry season. With the long dry
season, it causes serious drought situation, which is a potential risk of forest fire, for
example at U Minh Ha Melaleuca forest fired in March and April 2002.

8. Wind
There are 2 monsoon seasons per year: Northeast monsoon season often occurs from
November to April, and Southwest monsoon season is from May to October.
Northeast monsoon season including mainly Eastern wind occupies 50-70% of frequency
within a month with the average wind velocity of 3.3 m/s (in February), the maximum wind
velocity was 28.0 m/s (East direction, occurred in November, 1997 in Ca Mau).
Southwest monsoon season is mainly generated by West direction (about 40 - 50% in
monthly frequency) with the highest average wind velocity of 1.8 m/s. In this period, the
highest wind velocity was 28 m/s. Wind roses of Ca Mau area is presented in Figure 3.1.

9. Special Climatic Phenomena
Generally, storms and tropical low pressures scarcely land directly to the coastline of the
Mekong Delta area. Because local people do not have the custom of storm prevention and
protection, moreover, due to low and flat terrain, so the storms landing often cause great
damages in a large area.
In the period of 1997 - 1999, there were some typical storms such as storm No.5
(LINDA, 1997), tropical low pressures or the storm No.7 (1998), the storm No.10 (1999)
landed to the inland or to the coast then be weaken. The damage caused by storms is
severely, for example, the storm No.5 landed to the coastal zone of the Mekong Delta in
November 5th, 1997. It landed directly to Ca Mau with rainfall of 278 mm in 10 days (from
November 1st to November 9th) and it is 2 times higher than the usual average rainfall in
November.
In 1999, rainfall in Ca Mau is unusual, precipitation in April is at a high level (447mm, 4 times
higher than the average value at the same time in many years). In June, rainfall is highest in
a year (496mm) that higher than the average one in many years at the same time (324mm)
is 172 mm. In October, the second rainfall peak of the year, rainfall in October, 1999 is
476mm, in which rainfall in the last 10 days of October is 264mm. These special climatic
phenomenons are main reasons caused storms, heavy rain, great damages to properties
and human living in the Mekong Delta.



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The storm No.4 at the end of 2004 caused some damages to properties. There were 180
damaged houses and 03 damaged classes in Ca Mau City, 03 roofs - blow up houses in
Nam Can, and 71 families were influenced due to unsteady irrigational embankment which
made water flooding the agricultural land and lost farm products, fruits and cattles with total
damaged value of 250 millions VND [3].
At the beginning months of 2005, prolonged drought caused droughts at some places in the
area affected to agriculture production (fruits, farm products...) and fishery aquaculture
(shrimps were infected by diseases and died by salinity increasing in a large area) [3].

3.2.2 Air quality in the project area [4]
To assess air quality at the CM2 power plant area and its vicinity, RDCPSE had conducted
measurement and analysis of air quality and microclimate at 3 sites (Figure 3.2). The
measurement was carried out during the period of 19-24th December, 2005. The analytical
results of air quality at the project area and Cai Tau residential area are given in Table 3.6.
               Table 3.6 ANALYTICAL RESULTS OF AIR QUALITY (day average)
               AT PROJECT AREA AND CAI TAU RESIDENTIAL AREA IN 2005

                                                          Parameters (mg/m3)
     Sampling site
                           H2S       CO          NO2      SO2          O3      NH3      Pb      VOC        Dust
                                             CM 2 Power Plant area

CM2 power plant           0.0012    2.1356      0.0140   0.0199      0.0417   0.0281   <0.01    <0.05     0.238
(KK1)
1600m far from CM1
power plant 's stack to   0.0015    2.1835      0.0118   0.0191      0.0437   0.0283   <0.01    <0.05     0.216
Southern direction
(KK2)
CM2 power plant –
measured in rainy         0.002      1.096      0.016    0.023        0.028    0.048   <0.01    <0.05          -
season-2002
                                           Cai Tau residential area
Cai Tau residential       0.0021      1.938     0.0148   0.0248       0.048    0.052   <0.01    <0.05     0.234
area (KK3)
Cai Tau residential
area – measured in        0.002      1.055      0.014    0.019        0.029    0.047   <0.01    <0.05          -
2002
TCVN 5937-1995
(average 24 hrs)             -         5         0.1      0.3         0.06       -     0.005      -           0.2
Source: RDCPSE, 2005

Because the air quality measurement were carried out at the beginning of the dry season
(December, 2005) but the rainy season in 2005 ended lately, So the analytical results will be
compared with the ones of air quality and microclimate at project's vicinity areas in the rainy
season, 2002 which are shown in Table 3.6. Generally, the measured pollutants in the air
increased, particularly carbon oxide (CO) and Ozon (O3) are high at all sampling sites. The
reasons are due to the CM1 power plant is in the hastily construction period and the number
of vehicles at Cai Tau residential area, Khanh An Commune is higher than that in 2002.
However, the measured air pollutants were still lower than the ambient air standards of
Vietnam except dust, which spreads from the construction area of CM1 power plant to CM2
power plant and Cai Tau residential area. It is noted that the sampling and measurement
carried out at the strong wind time due to tropical low pressures occurred at that time.


Noise and Vibration
CPMB– RDCPSE-Final report                                                                             June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)           34


The measured results of noise and vibration in the period of December, 2005 are shown in
Table 3.7.
                      Table 3.7 PARAMETERS OF NOISE AND VIBRATION
  No.          Measuring site               Date         Measured           Microclimate parameters
                                                           Time
                                                                           Noise (dB)       Vibration (dB)
   1          CM 2 Power Plant           20/12/2005         9h30              68.4               76.4
                   (KK1)
   2                                                        12h00             57.6               70.2
   3                                                        14h10             57.7               89.3
   4                                                        16h20             57.7               67.2
   5                                     21/12/2005         8h00              65.7               85.6
   6                                                        9h45              63.9               72.4
   7                                                        13h00             63.3               74.2
   8                                                        16h30             62.0               70.2
   9                                     22/12/2005         8h00              63.0               86.5
  10                                                        10h15             63.7               67.4
  11                                                        13h15             57.9               65.4
  12                                                        16h30             61.4               64.4
  13      Distance of 1600m far from     20/12/2005         9h10              56.8               69.2
           power plant 1's stack in
  14                                                        12h10             56.2               65.4
           Southern direction (KK2)
  15                                                        14h30             56.3               68.4
  16                                                        16h50             65.5               69.6
  17                                     21/12/2005         8h00              56.3               75.6
  18                                                        10h10             67.3               89.7
  19                                                        13h10             54.4               72.1
  20                                                        16h45             56.4               68.7
  21                                     22/12/2005         7h45              56.9               69.5
  22                                                        10h00             56.3               72.5
  23                                                        13h00             56.7               70.2
  24                                                        16h20             55.8               69.9
  25       Cai Tau residential area      20/12/2005         8h00              66.8               72.3
                    (KK3)
  26                                                        11h15             67.2               76.7
  27                                                        14h00             57.5               69.1
  28                                                        16h40             56.5               65.7
  29                                     21/12/2005         8h10              55.7               62.4
  30                                                        11h10             54.6               65.4
  31                                                        14h00             62.2               82.3
  32                                                        16h40             66.8               75.6
  33                                     22/12/2005         8h15              66.9               72.4
  34                                                        11h00             63.6               76.9
  35                                                        14h05             63.6               69.8
  36                                                        16h45             62.4               68.9
                       Vietnamese Standards                                  75 (*)              75**
Source: RDCPSE, 2005
        (*) TCVN 5949:1995 Applied for production area intermixed with residential area, from 6-18 hours.
        (**) TCVN 6962:2001 Applied for production area intermixed with residential area, from 7-19 hours.
The measured results of noise and vibration [4] at the project area in December, 2005 are
lower than allowance limits. However, at some measuring sites at the CM2 power plant and

CPMB– RDCPSE-Final report                                                                           June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      35


its vicinity, the measured results are higher than allowance limits because of the operation of
constructive machines at the CM1 power plant.

3.2.3 Hydrology Regime and Surface Water Quality

3.2.3.1 Hydrology regime at Cai Tau Confluence Area

The project area is a confluence of 3 main rivers including Ong Doc, Cai Tau and Trem
rivers. Like other confluences, this area is affected by tide of southwestern sea, of Cai Tau
River from U Minh Ha upstream and Trem River from Rach Gia estuary. Furthermore, West
sea tide from Ong Doc estuary as well as East sea tide from Ganh Hao river through Tac
Thu canal and other canals in southern of Chac Bang Canal also influences this area.
Moreover, it is affected indirectly by Hau River. The tidal regime at Ong Doc rivermouth and
Rach Gia is not phase-synchronization. Therefore, the variation of the current is very
complex.

Direct effects of West sea tides to the project area are as follows:

-   At the spring- tide, the main tidal direction is from Ong Doc river leading to strong effect
    on Tac Thu confluence. At the Tac Thu confluence area, one tidal direction goes into Tac
    Thu river and another goes reverse up to Cai Tau confluence. Then, the tide continues
    going in by two directions: one to Cai Tau rivulet and another to Tieu Dua rivulet.
    Therefore, Tac Thu river is conjunction between East and West tides. The main water
    interface between East and West tides is slanting toward the Ong Doc river.

-   At ebb-tide, the area from Cai Tau conjunction to Tac Thu conjunction, there are two
    supplementary sources such as: from Trem, Cai Tau rivers and from Tac Thu river. As
    the result, tidal foot rises. Rising water phenomenon is mostly clear during heavy rain
    period, especially in October coincided with spring-tidal period (water level amplitude
    measured in October 1989 varied from 15 - 20cm), which not only limits drainage ability
    via the area but also limits that one of the U Minh Ha area generally.

-   The tidal amplitude in this area is quite small. In the rainy season/ flood season, the
    variation of tidal amplitude is from 20-30 cm. In the dry season/ ebb season, the tidal
    amplitude varies from 45-60 cm. The lowest tidal foot varies from -15 cm to -30 cm while
    the crest of tide drops down. In the flood season, the crest of tide varies from 50-60 cm.

Variation of water level and current after having Tac Thu dock:

-   When Tac Thu dock exists, some issues will be solved as: preventing salinity intrusion
    from Ong Doc river to upstream, drainaging out acid water in June and flood water in
    October as well as keeping water for U Minh area and its vicinity.

-   For upstream of Tac Thu dock: Average water level will be lower about 8-10cm in the dry
    season (due to high water consumption), so west tide through Cai Lon rivermouth will
    intrude furthermore into Chac Bang canal, salinity water will intrude to Vinh Thuan area.

-   For downstream area of Tac Thu dock: as high tide, water level at downstream of Tac
    Thu dock is about 25 - 28cm higher than the one at upstream. Current passing through
    dock is one-way current and depends on operation of dock. Current characteristic at Tac
    Thu station is summarized in Table 3.8.

      Table 3.8 SUMMARY OF CURRENT CHARACTERISTIC AT TAC THU STATION
            Characteristics                              Flow rate Measurement period
CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)               36


                                          09-23/X/1989     08-23/VI/1990     08-23/II/1990      21/II-08/III/2002
  Hmax (cm)                                    65               52                50                   40
  Hmin (cm)                                    28              -15               -30                  -13
  Hbq (cm)                                     56               19                14                   13
  Amplitude (cm)                               20               50                57                   44
  Q+max (m3/s)                               120.2             61.5             54.9                  95.3
  Q-max (m3/s)                               -67.5              0.0             -47.6               -103.2
  Qbq (m3/s)                                  36.3             31.4              15.6                  7.2
  Number of hour for down flow            14-16 hrs         20-22 hrs        14-16 hrs           12-14 hrs
  Number of hour for back flow              4-5 hrs           0 hrs            4-6 hrs             7-8 hrs
  Number of hour for stand water            2-3 hrs          1-2 hrs           1-2 hrs             1-2 hrs
Source: Sub-Institute of Water Resources Planning, 2002
Note:   - Amplitude: amplitude of highest daily water level;
        - Q (+)max: the highest down flow (flow out toward West sea)
        - Q(-)max: the highest back flow (flow in from West sea)
        - Qbq:       average flow rate at measurement period
        - Tac Thu station on Ong Doc river, about 1km far from Tac Thu-Ong Doc confluence toward Ong Doc
        rivermouth.

According to the requirement of the detail design For Ca Mau Gas - Power - Fertilizer
Complex project, Southern Institute of Water Resources Research had undertaken the
measurement of hydraulic regime at 5 stations (Figure 3.3) at Cai Tau confluence including
Ong Doc, Trem, Cai Tau rivers and Minh Ha canal in both dry and rainy season: the first
period (dry season) lasted from 24th to 29th April, 2002 and the second one (rainy season)
lasted from 22nd to 27th July, 2002. The detail assessment report on hydrological regime at
the Ca Mau Gas – Power- Fertilizer Complex is presented in 3 specific separated reports.
Some results of this survey are summarized in Table 3.9 [5].
     Table 3.9 HYDROLOGICAL CHARACTERISTICS IN THE CA MAU GAS-POWER-
           FERTILIZER COMPLEX IN BOTH DRY AND RAINY SEASONS, 2002
         Characteristics             Season       TV.1         TV.2          TV.3         TV.4       TV.5
                                        I         0.26          0.26         0.25         0.26           0.32
           Hmax (m)
                                       II         0.31          0.29         0.29         0.30           0.35
                                        I         0.13          0.15         0.14         0.13           0.17
            Hmin (m)
                                       II         0.22          0.20         0.19         0.21           0.18
                                        I         0.21          0.20         0.20         0.19           0.25
             Hbq (m)
                                       II         0.26          0.25         0.23         0.25           0.25
                                        I         0.13          0.11         0.11         0.13           0.15
         Amplitude (m)
                                       II         0.09          0.09         0.10         0.09           0.17
                                        I         0.12          0.08         0.06         0.13           0.06
         Vmax(+) (m/s)
                                       II         0.14          0.11         0.18         0.18           0.08
                                        I         0.15          0.16         0.13         0.18           0.10
         Vmax(-) (m/s)
                                       II         0.12          0.14         0.13         0.15           0.11
                      3                 I         23.08         8.33         6.46        33.82           3.96
         Qmax(+) (m /s)
                                       II         28.48         3.07        19.58        46.35           5.07
                                        I         30.82        17.76        14.25        45.81           5.94
         Qmax(-) (m3/s)
                                       II         24.68         4.02        14.35        39.95           7.27
                    3                   I         4.31          1.34         0.88         4.55           0.16
         Qbq(+) (m /s)
                                       II         15.39         1.46        10.06        25.49           2.43
                                        I         6.69          2.93         2.21         8.38           1.25
          Qbq(-) (m3/s)
                                       II         12.44         1.88         8.19        28.49           3.39
                                        I        284.82       164.35       159.27        459.90         130.99
        Total volume (m3)
                                       II         2.256        0.103        1.327        3.731           0.604
Source: Southern Institute of Water Resource Research, 2002.
Notes: TV.1      Trem river - 1,500m far from Cai Tau confluence
         TV.2    Cai Tau confluence (Period I) and Trai Giam canal (Period II)
        TV.3     Cai Tau river - 1,500m far from Cai Tau confluence

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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)             37

        TV.4      Ong Đoc river - 1,500m far from Cai Tau confluence
        TV.5       Minh Ha canal
        Period I: Hydrological period in dry season (24-29 April, 02)
        Period II: Hydrological period in rainy season (22-27 July,02)
        Q(+)max: the highest down flow; Q(-)max: the highest back flow
        Convention of flow directions: Flow out to the West sea (+), down flow; Flow in from the West sea (-),
        back flow

The results from above table show that, the hydraulic regime in the Ca Mau gas-fertilizer-
power complex is summarized as follows:
- In general, water level of the area has variation though it is not directly affected from the
   western of Hau river but due to rainfall, the main source caused flooding in the area and
   river morphology so the drainage capacity is limited.
- Because of the small oscillation in tidal amplitude, drainage capacity in this area is very
   limited and difficult, especially when having heavy rains simultaneously with flooding
   from Hau river caused inundation in large area.
- In the drought months in dry season, the current regime in the rivers depends mainly on
   tidal currents and the tidal effects from Ong Doc river. However, in the flooding period,
   besides the direct influence of tidal current, this area is also partly influenced by flood
   flowing from upstream of the Mekong river. This makes current circulation more
   complicated and the water velocity decreases. Therefore, the weak dispersion ability and
   weak transportation of suspended sediment cause alluvia deposition phenomenon in the
   canal system.
- Based on collected data from many years as well as site measurement results, it can be
   said that drainage ability in this area is suitable with long lasted ebb-tide, but it has a
   significant disadvantage with high tidal foot and small amplitude which makes much
   decrease of drainage capacity. The main drainage direction in Cai Tau confluence is
   running towards Ong Doc River.
Inundation situation
Inundation phenomenon in the area is not only caused by raining but also by tide. The area
is usually flooded in rainy season with flooding time lasts from 2 - 3 months (end of August to
end of October) with general flooding depth of 0.3 - 0.5m, particularly of over 0.6m in some
areas (Figure 3.3a). Besides, low riverside lands of the area are also inundated during spring
tidal period of the year (December - January).
Existing main hydraulic constructions in the project area [6]
-   Along Ong Doc river, from estuary to Tac Thu confluence, there is an embankment with
    38.5 km long and 500 m far from river on which is used as a road of 6m wide. High level
    of embankment is +2.0 to + 2.2m. Below it, there are some small sluices with 1 - 5m in
    width, from -0.5 to -1.5m in height.
-   Along Cai Tau river, there are embankments in both riversides with 6m wide and 1.5-
    2.2m high.
-   Along Trem river, there is embankment in western riverbank with 41km long, 6m wide
    and +1.5m to +2.2m high, without sluice below. At eastern riverbank, there is
    embankment with 24km long, 6m wide and + 1.5m to + 2.2m high. Below it, there is
    sluice with 1.8m wide and 1m high.
-   Now, the construction of the Tac Thu sluice and dock and Bien Nhi sluice finished at the
    end of 2005 and they will be used in March, 2006. The operation of Tac Thu and Bien Nhi
    sluices can intake the seawater into the aquacultural ponds at the suitable time for shrimp
    aquacultural activities at some areas along Cai Tau and Trem riverbanks. Besides, they
    can also supply freshwater to prevent forest fire and to produce double rice crops.

CPMB– RDCPSE-Final report                                                                             June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)             38


Proposed operation of Tac Thu sluice

Tac Thu sluice will be closed to the end of January for keeping freshwater. In December and
January, freshwater will be pumped up and stored in order to supply water for trees and
forest fire-fighting in the dry season.
In February, after pumping enough water for forest-storage and other demands, Tac Thu and
Bien Nhi sluices are operated to take seawater for shrimp aquacultural activities until the end
of May. The sluice will be opened to get seawater at spring tide and will be closed at ebb-
tide. The purpose is to reduce of expenditure of pumping seawater for shrimp aquacultural
activities. The operation (open/close) of the sluice depends on the shrimp's growing periods.
When the period of producing shrimps finishes (from June to October), the sluice will be
operated one-way in order to prevent salinity intrusion, drainage acid water (alum water) and
flood water. So, the shrimp aquacultural areas will be changed to growing rice.

3.2.3.2 Water quality
Basing on the options of wastewater and cooling water discharge in CM1 & CM2 power
plants, RDCPSE had conducted the measurement and analysis of water quality at 4 sites in
Cai Tau and Ong Doc river systems (downstream of Tac Thu dock) in December, 2005
(Figure 3.2). The measured and analysed results are shown in Table 3.10.
    Table 3.10 PHYSIO-CHEMICAL PARAMETERS OF SURFACE WATER AT CA MAU
                                POWER PLANT IN 2005

              Site                   pH            T0C        EC (mS/cm)       Salinity (‰)     DO (mg/l)
           RW-1.1                   6.95          25.7            15.3             8.6             5.87
           RW-1.2                   6.93          27.3            15.2             8.4             6.20
           RW-2.1                   7.12          23.6            15.6             8.7             5.90
           RW-2.2                   7.10          26.4            19.6             11.1            5.90
           RW-3.1                   7.15          26.5            21.8             12.7            4.85
           RW-3.2                   7.25          28.1            19.9             11.3            6.10
           RW-4.1                   7.21          26.8            22.1             12.7            4.68
           RW-4.2                   7.21          27.0            21.1             12.2            5.70
        Average-in dry
                                    7.53          31.8            50.2             31.5            7.08
       season – 5/2002
       Average-in rainy
                                    4.07          31.6            10.3             5.7             7.43
       season – 7/2002
       TCVN 5942-1995              5.5-9            -               -                -              ≥2
Source: RDCPSE, 2005
Notes:
    -   RW 1.1: Cai Tau river, discharge site is 1.5-2 km upstream far from power plant at high tide; and RW 1.2
        at ebb-tide.
    -   RW 2.1: Cai Tau river (where to take cooling-water for both power plants): high-tide; RW 2.2: ebb-tide.
    -   RW 3.1: Ong Doc River (500m downstream far from Tac Thu dock): high-tide; RW 3.2: ebb-tide.
    -   RW 4.1: Ong Doc river (1000m downstream far from Tac Thu dock): high-tide, RW 4.2: ebb-tide.

To compare with analytical results on Cai Tau and Ong Doc rivers in 2002 and 2005, it is
summarized as follows:
 - Because the rainy season in 2005 (December, 2005) lasted longer with heavy rainfall, so
   pH was increased, and the salinity was distinctly lower in 2005 in comparison with
   average one measured in dry season of 2002;
 - The river's temperature in 2005 (23.6 - 28.1oC) was lower than in 2002 (31.6 - 31.8oC).
The analytical results on chemical components of the surface water quality at the project
area in December 2005 are given in Table 3.11.

CPMB– RDCPSE-Final report                                                                           June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                                             39


    Table 3.11 ANALYSED RESULTS OF CHEMICAL PARAMETERS OF SURFACE WATER

          Site                                                    Parameters (mg/l)
                      Phenol                           Total       Total
                                   DTS       TSS                                 NH4+         NO3-         NO2-           SO42-          BOD5
                      (μg/l)                            N           P
        RW - 1.1        <5        0.062      84.29     3.587       0.025         0.723        0.190        0.072      1378.42            3.28
        RW – 1.2        <5        0.067      40.00     3.259       0.022         0.508        0.237        0.071      1349.09            3.47
     RW – 2.1           <5        0.072      42.06     2.762       0.033         0.664        0.190        0.112       792.83            2.93
     RW – 2.2           <5        0.071      46.00     3.205       0.042         0.508        0.172        0.144       996.17            1.56
     RW – 3.1           <5        0.070      53.12     3.244       0.083         0.773        0.175        0.074       977.60            2.77
     RW – 3.2           <5        0.066      78.37     2.604       0.064         0.561        0.182        0.090       990.31            2.44
     RW – 4.1           <5        0.067      43.33     2.766       0.080         0.724        0.180        0.071      1148.68            3.55
     RW – 4.2           <5        0.057      41.88     2.516       0055          0.753        0.193        0.062      1196.58            2.37
  Average 2002          <5        0.026        -        1.50       0.083          0.56         0.07         0.05        3400             3.30
    TCVN 5942-
                       20       0.3               -         -        1       15       0.05       -         <25
       1995
Source: RDCPSE, 2005
Notes:
- RW 1.1: Cai Tau River, the cooling water discharge position is 1.5 -2 km upstream far from the Power Plant :
   high-tide; RW 1.2: ebb-tide.
- RW 2.1: Cai Tau river (where to take cooling- water for both Power Plants): high-tide, RW 2.2: ebb-tide.
- RW 3.1: Ong Doc river (500 m downstream far from the Tac Thu dock): high-tide; RW 3.2: ebb-tide.
- RW 4.1: Ong Doc river (1000 m downstream far from Tac Thu dock): high-tide; RW 4.2: ebb-tide.

Comparison the baseline survey results in 2002 and 2005 in all sampling sites with
Vietnamese Standard TCVN 5942 - 1995, show as follows:
-       The total oil content (DTS), total N, NH4+, NO3-, NO2- in 2005 is higher than in 2002 but
        still lower than allowable limits.
    - Especially, at station R2 , NO2- concentration was exceeded the allowance standard. It
      means that water on Cai Tau river where cooling water intakes has signal for pollution.
                   Table 3.12 HEAVY METAL CONTENT IN SURFACE WATER (mg/l)

No.       Sample     Zn          Cu        Ba         Pb         Cd         Fe           Ni           Cr           Mn             Hg        As

                                                                      ppm                                                                  ppb
    1    RW-1.1-KL < 0.005     < 0.005    < 0.25     0.010     < 0.005      3.69     < 0.08       < 0.08           0.65      < 0.001       0.70
    2    RW-1.2-KL < 0.005     < 0.005    < 0.25     0.004     < 0.005      2.13     < 0.08       < 0.08           0.59      < 0.001       0.70
    3    RW-2.1-KL < 0.005     < 0.005    < 0.25     0.002     < 0.005      1.53     < 0.08       < 0.08           0.33      < 0.001       0.40
    4    RW-2.2-KL < 0.005     < 0.005    < 0.25     0.002     < 0.005      1.64     < 0.08       < 0.08           0.31      < 0.001       0.60
    5    RW-3.1-KL < 0.005     < 0.005    < 0.25     0.002     < 0.005      1.21     < 0.08       < 0.08           0.24      < 0.001       0.70
    6    RW-3.2-KL < 0.005     < 0.005    < 0.25     0.005     < 0.005      1.30     < 0.08       < 0.08           0.23      < 0.001       0.50
    7    RW-4.1-KL < 0.005     < 0.005    < 0.25     0.003     < 0.005      2.47     < 0.08       < 0.08           0.27      < 0.001       1.00
    8   RW-4.2–KL < 0.005      < 0.005    <0.25      0.002     < 0.005      0.95     < 0.08       < 0.08           0.20      < 0.001       0.70
Average 2002 < 0.005           < 0.005    <0.25      0.001     < 0.005      0.62     < 0.08       < 0.08           0.63      < 0.001       0.87
TCVN 5942-1995   2               1          4        0.1        0.02         2           1            1            0.8       0.002             -
Source: RDCPSE, 2005
The analytical result of heavy metal content in surface water at the project area and its
vicinity in 2005 shows that:
- Most of the metal contents in surface water are below the allowance limit.
-       The iron (Fe) content in 2005 is much higher than in 2002 but is still within the allowance
        limits of TCVN 5942 - 1995 (column B).
3.2.4 Sediment quality

        Grain size distribution [4]
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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                                                                   40



The analytical results on grain size of sediment samples at Cai Tau and Ong Doc rivers are
shown in the below diagram:


                                                           Total OM                   AVE 2002          Sidement                 AVE 2002
                                                                                                                                                                          Formatted: Font: Bold
                                        150
            Total OM (microgram/gram)




                                                                                                               TB 2002 = 128                                              Formatted: Font: 10 pt
                                                                           117
                                        100
                                                     83
                                                                                             77               79
                                                                                                                           70

                                        50
                                                                                                    AVE 2002 = 29.2

                                                                                                                                                  1.5
                                          0
                                                     R1               R2                R3               R4                ? 1              ? 2

                                                                                              Station

Source: RDCPSE, 2005

According to the analytical results, the sediments at 4 sampling sites are quite homogenous
and fine silt. The comparision with analytical results in 2002 shows that the sediment from
the upstream to the confluence of Cai Tau river and Ong Doc river (downstream of Tac Thu
dock) is fine silt and has not much variation.

      Hydrocarbon content

The analytical results of hydrocarbon in sediment in 2005 at 4 sites varied from 77-177 µg/g.
Among them, highest value is at station R2, the place to take cooling water for two power
plants. The high hydrocarbon content is due to this site locates closely Cai Tau residential
area and the river confluence. So, it is received the waste discharges from human activities.

      Metals in sediment
The analytical results of metal content in sediment on Cai Tau and Ong Doc rivers in 2005
are shown in the table 3.13.
                                                   Table 3.13 HEAVY METAL CONTENTS IN SEDIMENT
                                              Cu          Pb      Zn             Cd          Ba         Ni          Cr       Mn         Hg              As        Fe
No.
       Samples
                                                                                               (µg/g)                                                            (%)
 1    S - 1.1 - KL                        30.68      21.44       89.38       <1              214   29.78           64.86     267       0.32             6.80     4.03
 2    S - 1.2 - KL                        30.03      20.81       88.90       <1              196   31.49           61.29     273       0.05             6.30     4.00
 3    S - 2.1 - KL                        28.94      23.79      101.82       <1              187   28.31           57.68     190       0.95             5.10     7.07
 4    S - 2.2 - KL                        27.69      15.18       80.23       <1              173   24.58           55.65     148       0.08             3.10     8.52
 5    S -3.1 - KL                         36.93      21.06      108.51       <1              224   35.13           67.96     330       0.21             5.60     3.45
 6    S - 3.2 - KL                        31.77      21.67      110.33       <1              202   34.33           62.32     300       0.07             5.30     3.61
 7    S - 4.1 - KL                        34.88      20.35      112.26       <1              185   33.86           57.25     273       0.09             6.60     4.33
 8    S - 4.2 - KL                        30.88      22.50       97.17       <1              201   31.42           60.37     465       0.23             6.40     3.26
 Average 2002                                 34          19      91         <1              190    26              58       320      0.068             16        3.1
Source: RDCPSE - 2005
The above results show that the iron (Fe) content is high on Cai Tau river (where to take
cooling water). This can be due to washing out of acid sulfate soil process. The acid sulfate
soil contains a lot of pyrites (FeS2) which causes increasing iron ion in river bottom sediment.
CPMB– RDCPSE-Final report                                                                                                                                    June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      41



However, to compare with the analytical results in the dry season on Cai Tau river (N3), in
2002, the iron content in sediment obviously increases in the rainy season in 2005. Other
parameters such as Ba, Mn, etc. in the rainy season of 2005 are higher than in 2002; but Hg
and Cd are still low.

3.2.5 Hydrogeology and groundwater quality

Refer to the document of "Existing investigation, evaluation and forecasting variation of
groundwater capacity, quality and exploitation planning in Ca Mau province" shows that
hydrogeology in Ca Mau can be divided into 6 main aquifer strata as below [7]:

    Stratum 1 – Holocene aquifer stratum (QIV): distributes in the whole province, two per
    three (2/3) area is often submerged. The bottom depth is from 30 to 42 m. The
    composition mainly consists of clay silt, sand, fine sand clay, humus, having ash-grey,
    brown-grey colour with the thickness of 30 - 50 m. Groundwater is completely brackish
    water due to the interaction with the river/ canal surface water (affected by tide).
    Characteristic of this aquifer is hard water, pH = 7.7-8.3, carbonic corrosion and nitrite
    pollution (NO2- = 0.53-21 mg/l).

    Stratum 2 - middle Pleistocene - late aquifer stratum (QII-III): is located under QIV layer
    and covers in the whole province. Depth of the bottom layer is in the range of 98-136m.
    The isolated layer with QIV stratum is clay and mixing clay; the below is gravel sand
    layer containing water. Water in this layer is generally fresh water.

    Stratum 3 - early Pleistocene (QI) aquifer stratum: is located under the QII-III layer and
    cover in the whole province. Depth of the bottom layer is 160-200m. The isolated layer
    with QII-III stratum is the clay and mixing clay; the below is gravel sand layer containing
    water. At the present, water in this aquifer is generally fresh, soft and contaminated by
    nitrite, nitrate. It is possible to get brackish water at the depth of 170m (Tan An Dong
    village).

    Stratum 4 - Pliocene aquifer stratum (N2): located under QI stratum and extend to the
    whole province. Water in this layer is generally fresh, soft and contaminated by nitrite,
    nitrate and a lot of residue.

    Stratum 5 - N13: this stratum is located under N21 stratum and not covered in the whole
    province.

    Stratum 6: fissure water in base stones before Kainozoi period: it is exposed at the Hon
    Khoai, Hon Chuoi islets, At Nam Can Town, fissure water can be found at 372m depth
    (granite).

The analytical results of ground-water quality at a drilling-well at Power Plant 2 in 2005 and
the comparison with the analytical results of groundwater in 2002 in this area [5] are shown
in the table 3.14.




              Table 3.14 ANALYTICAL RESULTS OF GROUNDWATER QUALITY
                                 AT THE PROJECT AREA

CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                   42


 Parameters                                      Results in             Average results in             TCVN
                                                  12/2005                    2002                    5944:1995
 pH                                                 7.55                      7.36                    6.5 - 8.5
 Temperature (0C)                                    30                         -                         -
 Conductivity (mS/cm)                               1.48                      0.85                        -
 Salinity (‰)                                        0.8                       0.5                        -
 Hardness (mg CaCO3/l)                             200.5                      153                    300 - 500
 TDS (mg/l)                                         540                       371                         -
 Cl- (mg/l)                                        109.9                       87                    200 - 600
 TSS (mg/l)                                         2.67                       49                    750 - 1500
 NO3- (mg/l)                                       0.016                     0.243                       45
 NO2- (mg/l)                                       0.002                     0.078                        -
 SO4-2 (mg/l)                                       0.49                      2.3                       200
 Phenol (μg/l)                                       <5                        <5                         1
 Feacal coliform (MPN/100ml)                          8                       140                         -
 Coliform (MPN/100ml)                                23                      4593                         3
Source: RDCPSE - 2005

    Table 3.15 RESULTS OF HEAVY METAL CONTENTS IN GROUNDWATER AT THE
                               PROJECT AREA
                                                                                                       Hg       As
  Parameters      Zn        Cu       Ba        Pb        Cd      Fe                Cr       Mn
                                                                           Ni                         ppm       ppb


     2005       < 0.005   < 0.005   < 0.25   < 0.001   < 0.005   0.57    < 0.08   < 0.08   < 0.03    < 0.001   <0.20

 Average 2002   0.098     < 0.005   < 0.25   < 0.001   < 0.005   1.01    < 0.08   < 0.08   < 0.03    < 0.001   <0.20
  TCVN 5944-
                  5         1.0       -       0.05      0.01     1-5       -      0.05     0.1-0.5   0.001      0.05
  1995 (mg/l)
Source: RDCPSE - 2005

The analytical result of groundwater quality at the project area in 2002 and in 2005 shows
that all of the water quality parameters are below the allowance limits of Vietnamese
Standards TCVN 5944-1995, except the Coliform.

3.2.6 Characteristics of Topography and Geology [7]
    Topography
Ca Mau is annual alluvial deposit ground and in general, the geographical structure is weak.
Topography in Ca Mau is divided into five zones of ecological topography as follows:
1. Topography of triangular delta sediment: Ca Mau City is ecological region with the
   highest altitude. Average elevation of Ca Mau City is from 0.9-1.3m and the elevation of
   the surrounding fields is about 0.5-0.7m (the altitude system of Mui Nai Cape, Ha Tien).
2. Topography of alluvial deposit cape: it includes almost districts belonging to the province
   such as Ngoc Hien, Dam Doi, Cai Nuoc, U Minh, Tran Van Thoi and one part of Ca Mau
   City. The region is covered by mangrove absolutely affected by tidal regime with a lot of
   complex water transition areas, high rainfall; therefore, aquatic-forest products are
   abundant and a place of the special one rice-crop.
3. Topography of Hollow rain water submerged region: the typical region is in Thoi Binh, U
   Minh districts. This is covered by Melaleuca forest on low area and due to high rainfall
   here, it is difficult to drain.
4. Topography of central suspended edge region: It is located in Thoi Binh district and is a
   sub-region with favourable soil condition, high rainfall, rare submergence.

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5. Topography of central hollow at Co estuary: belonging to U Minh, Thoi Binh districts.
   This area is submerged and salinity and acid sulphate contaminated.
       Geology

Based on the geological survey report at Ca Mau Gas-Power-Fertilizer Complex undertaken
by Power Engineering Consulting Company No.2 in October, 2003, the total 6 soil layers and
2 sub-layers are identified as follows:
-      Layer 1: melt clay silt with average thickness of 16 m, low intensity of cutting and
       compressive resistance, high sensitivity;
-      Layer 2: Flexible hard clay to semi-hard with relative high intensity of cutting and
       compressive resistance, but thin thickness (lower than 11 m).
-      Layer 3: Flexible soft clay to flexible hard clay containing humus and poor homogenous.
-      Layer 4: sandy clay alternating clay layers with intensity of high cutting and compressive
       resistance, but thin thickness (average 3.6 m) and poor homogenous.
-      Layer 5: semi-hard clay alternating fine sand layer at the depth of 40-45 m. Although
       intensity of cutting and compressive resistance is at mean level but the result of
       horizontal compressive resistance shows that compressive module and the thickness are
       very high (more than 30 m).
-      Layer 6 and sub-layer 5a: these layers have rather high intensity of cutting and
       compressive resistance, higher than upper layers.

Analysis result of each soil layer shows that the depth foundation solution is suitable. The
5.5a and 6 layers may be made as base for pile foundation feet. For works having small
concentrative loading capacity, piles may be driven through thick and soft layer 1, thin clay
layer 2 and inhomogeneous layers 3 & 4.
The analytical result of metal content in soil samples at the project area in 2005 [4] is given
in Table 3.16.

        Table 3.16 ANALYTICAL RESULT OF METAL CONTENT IN SOIL SAMPLES (µg/g)

     Samples         Cu      Pb      Zn      Cd       Ba        Ni       Cr      Mn       Hg       As    Fe (%)

    S - Đ1.1 - KL   27.38   16.05   74.65    <1       186     26.50    63.73     297      0.05    5.20    3.06

    S - Đ1.2 - KL   30.41   22.21   76.60    <1       203     28.57    70.10     280      0.12    6.20    3.29

    S - Đ2.1 - KL   19.12   18.25   48.96    <1       308     15.66    35.39     269      0.03    6.80    2.14

    S - Đ2.2 - KL   17.69   19.77   45.09    <1       265     14.24    29.60     257      0.03    4.70    1.76
   TCVN
                 100      300     300     10         -        -        -         -        -         12        -
7209:2002 (*)
Source: RDCPSE, 2005.
Notes: Đ1: closed to Power Plant 1
        Đ2: gate of Power Plant 2
        TCVN 7209:2002 (*): Maximum limits of total As, Cd, Pb, and Zn - applied for industrial land.

The analytical result of metal content at the CM2 power plant (in the proposed area of
Fertilizer Plant) in two years (2002 & 2005) shows that the contents of Arsenic (As), Cadimi
(Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) are much lower than the Vietnamese Standards
TCVN 7209:2002 which are applied for industrial land.

3.2.7 Seismic, earthquake and erosion situation

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    Seismic and earthquake

The project area is not situated in pronounced earthquake epicenter area. According to MSK
scale, the earthquake intensity of 6 for the Ca Mau area is confirmed equivalent to ground
surface acceleration basic coefficient of 0.05 g.

    Erosion
Refer to the Report "Study on the shoreline erosion and variation along Southwest coastal
area from Ca Mau cape to Cambodian border" [8] undertaken by Ho Chi Minh City Physics
Sub-institute and the Report "Existing of riverside erosion in Ca Mau Province" prepared by
DoSTE of Ca Mau [9] show that the eroded areas often concentrate at the following areas:
• The coastal zone: the Eastern coastline was eroded much stronger than the Western
  coastline. Toward to the western sea, in the coastal area of Thailand gulf belonging to U
  Minh, Tran Van Thoi districts during 1992 - 2001 was eroded about 100-335m. In addition,
  the coastal zone, from Ganh Hao estuary to Ho Gui River mouth (Dam Doi district), was
  strongly eroded with the rate of more than 10m/year.
• The riverside area: there are 3 strong eroded areas (erosion rate is more than 10 m/year)
  such as: Tan Tien market (Dam Doi district), Nam Can townlet, Nam Can port, Cai Nai
  hamlet (Ngoc Hien district), Ca Nay market (Ngoc Hien district). The result shows that the
  eroded areas often occur at the bendy sections, the river-confluence with the high tide
  amplitude and crowded inhabitants, constructive works and high density of boats
  anchoring at large flow rivers.
• In addition, at present, the usual and important eroded routes have high density of boats
  such as: Bay Hap river from Ca Mau to Dam Cung, Ong Doc river from Ca Mau city to
  Ong Doc river mouth. The main reason is due to waves generating from waterway
  transport means (mainly is heavy loading and high-speed ships)

Period of erosion occurrences are often in three months from May to August, especially in
May and June. This period coincides with the duration of lowest tidal peak corresponding to
the lowest average water level on the rivers/canals and also in the beginning of the rainy
season. Most erosion cases happened in heavy rains, at the lowest ebb-tide and at night
time.

3.3     BIOLOGICAL CHARACTERISTICS
3.3.1 Terrestrial ecosystem

    Flora system

Based on the vegetation field surveys in 2002, 2003 and 2005 conducted by RDCPSE,
there are two main flora groups in the project area and its vicinity as follows: semi-natural
melaleuca forest, planting melaleuca forest and seasonal flooded grassland and crop plants.
At Ca Mau Gas-Power-Fertilizer Complex, vegetation is mainly rice-field, Eleocharis
grassland, hodgepodge plants, Melaleuca, Eucalyptus, coconut, Melastoma, Annona... In
the vicinity, Vo Doi specific forest is located 8.5 km far from the project area with following
characteristics:

♦ The structure of semi-natural melaleuca forest is separated to 2 distinguished layers.
  The wooden tree layer consists of melaleuca with density of 1 - 2 trees/m2. Other
  wooden trees are available with small quantity such as Ilex simosa and Alstonia
  spathulata. Regional liana ecosystem is especially well growth with Stenochlaena
  palustris, Flagellaria indica, Sumatra Scleria sumatrensis and Dioscorea glabra. On the

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    banks along the forest boundary, Stenochlaena palustris and Sumatra make thick
    brushes with the presence of Cayratia trifolia, Ageratum conyzoides, Thespis divaricata,
    Vigna luteola and Hygrophila salicifolia.

−   The planted melaleuca forest depending on varied ages distributes almost half of eastern
    region. In mature forest, it is often thinly and exists well growth vegetation closing on the
    ground. In addition, there are still grassplots with the natural regeneration of young
    melaleuca.
−   The grassplot community is predominant with Eleocharis dulcis, in addition, there are
    some grass plants exist: Cyperus halpan, Cyperus polystachyos, Fuirena umbellata,
    Philidrum lanuginosum and Phragmites vallatoria. There are occasionally Cyperus elatus
    and Cyperus digitatus mingling with Eleocharis grassplot and Phragmites. On the upper
    layer, Phragmites vallatoria is predominant. Moreover, there are other popular plants
    such as: Cayratia trifolia, Vigna luteola, Panicum repens and Melastoma affine.
    Phragmites vallatoria forms thick brush layer of 3m high.
−   The internal canals in Vo Doi special-use melaleuca forest have a diversity floral
    community with floating and submerged species like water-hyacinth (Eichornia
    crassipes), Pistia stratiotes, Salvinia cucullata, Ipomoea aquatica, Azolla pinnata,
    Spirodela polyrrhiza, Lemna aequinoxialis and rare wolffia is acute water-fern Lemna
    tenera (Tran Triet pers.comm).
−   Agriculture plants: the major agriculture plant is rice combined with forest planting and
    some other fruit trees such as: banana, papaya, coconut, etc. and other farm products.
    Moreover, Ca Mau province has planned 215 ha sugar cane at Thoi Binh and U Minh
    districts consisted of 127ha along Trem River, 88 ha at Khanh An resettlement area [10].

    Fauna
U Minh melaleuca forest is a favourable habitat for a lot of animals. At the beginning of the
rainy season, fish from rivers swimming into rice-fields and canals in malaleuca forest for
breeding and growing. Flooding water brings more alluvial and organic matter accompanied
with decayed compositions in the melaleuca forest to form a rich food source for plankton
and fresh-water small fish and shrimp. These organisms feed on carnivorous fish such as;
snake-head (Ophiocephalus striatus), Ophiocephalus micropeltes, Ophiocephalus lucius, to
make them growing well. Prawn, fish, amphibians are also a food source of otter, water-
snakes (Enhydric enhydris, Homalopsis buccata, Enhydris bocourti and green dendrophis
Trimeresurus popeorum).
The abundance of shrimps and fish in the melaleuca forest has attracted a lot of birds for
feeding such as: stork, heron, night heron, ibis, Phalacrocorax niger, Galinular chloropus. In
addition, there is also the presence of Ibis leucocephalus, Xenorynchus asiaticus. Cionia
episcopus, Pelecanus philippensis, Leptoptilos dubius. Besides, there are insectivorous
birds such as: Merops viridis, Lonchura punctulata, Ploceus philippensis burmanicus, Passer
montanus, Fringilla montifrigilla. Additionally, seasonal inundated condition has created
favourable habitat for deer, wild pig, weasel, wildcat, varan, pangolin, python. On the
melaleuca branch, there are bats, monkeys, squirrels, etc. (Phung Trung Ngan, 1987).
Insects in the melaleuca forest are rather abundant including 45 species belonging to 7
orders, in which bee species is dominant with honey-bee, wasp ... (Phung Trung Ngan,
1987).
According to previous surveys, at Vo Doi special-use forest, Tran Van Thoi, U Minh III
forestry farms, there are 12 amphibian species, 32 reptilian species, 100 species of birds, 18
mammalian species. Up to now, animals in melaleuca forest are reducing considerable.


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Tiger, panther, deer... cannot be found, the valuable rare birds are also reducing, the
remained amount remains not much [10].

The latest surveys of Birdlife Vietnam (2000) had recorded 82 bird species at Vo Doi special-
use forest, Tran Van Thoi, U Minh III forestry farms, where the quantity of bird species is the
third grade in comparison with other wetlands in the region. Birds are really abundant with
Chinese little bittern (Ixobrychus sinesis), Bronze-winged Jacana (Metopidius indicus) and
warbler (Porphyrio porphyrio). However, there are no recorded "threaten species" in this
area. According to Vo Doi forestry officers, woolly-necked stork (Cionia episcopus) is often
observed at the buffering zone. The environmental disturbance and destruction, especially
forest fire, are reasons caused disappearance of big water birds [9]. Forestry birds such as:
scarlet minivet (Pericrocotus brevirostris) and indochinese cuckoo shrike (Coracina
polioptera) are found in mature forest.

Besides, red squirrels (Calloscirius sp.) are often observed along the canal banks. Large
flying fox (Pteropus sp.) used to be famous before, they lived concentrated in a large area at
Vo Doi, but there are few at present. On the field survey along the gas pipeline conducted by
RDCPSE within 3 – 7th January, 2003, a flock of bats flying from Vo Doi special-use forest to
U Minh III forest was observed.

3.3.2 Aquatic ecosystem

      Phytoplankton [4]
The analytical results of phytoplankton in 2005 at the project area are summarized in the
Table 3.17.
                Table 3.17 THE ANALYTICAL RESULTS OF PHYTOPLANKTON
                                 AT THE PROJECT AREA

                                     Number of species                      Density (x1000 TB/m3)
         Phylum                        (/site(0,04m3)
                              R1        R2        R3        R4       R1            R2     R3       R4
 Bacillariophyta               19       12        22        25       842           460   1380     1148
 Chlorophyta                    1        1         0         1        20            16     0       14
 Chrysophyta                   0         1         0        0         0              4     0        0
 Cyanophyta                    3        2          2        6        396           184   1040      875
 Dinophyta                      1        0         1         1        14             0    28       11
 Euglenophyta                  6         2         2        1         66            20    28        4
 Total                         30       18        27        34      1,338          684   2,476    2,051
 Diversity (Hs)               3.21     3.26      2.71      3.60
Source: RDCPSE-2005
Notes: R1: Cai Tau river, at cooling water discharge site, upstream of the plant
        R2: Cai Tau river, cooling water intake site
        R3: Ong Doc river, 500m downstream far from Tac Thu dock
        R4: Ong Doc river, 1000m downstream far from Tac Thu dock.




The above result shows that:
  -    There are about 18-24 species found at 4 surveyed sites in 2005.

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  -    The founded species belong to 6 different algal phyla: Bacillariophyta, Cyanophyta,
       Euglenophyta, Chlorophyta, Dinophyta and Chrysophyta. Bacillariophyta is most
       dominant, occupying 71.6% total recorded species. Next are Cyanophyta,
       Euglenophyta, Chlorophyta, Dinophyta and Chrysophyta.
  -    Although density of phytoplankton in Cai Tau river (R1&R2) is lower than the one in
       Ong Doc river (R3&R4), the number of species is quite equal in both rivers. With the
       high number of species and density, the typical diversity parameters of community
       varied not much among the sites. Particularly, at R3 site, the diversity is low due to
       high density but low number of species. This is because the R3 site located on Ong
       Doc river, downstream of Tac Thu dock where there are a lot of fishery aquaculture
       activities. So at this site, the water is turbid because of discharged water from
       aquacultural ponds (the TSS equals 66, higher than three other sites). The
       development of phytoplankton community depends on the light. At the R2 site, the
       number of species and the density of community decrease significantly while the
       diversity is still high. This site is located next to Cai Tau residential area so, it is
       polluted by organic matters (the NO2- in the surface water is 0.13 mg/l, exceed the
       permitted limits 0.05 mg/l - TCVN).

       Zooplankton

The analytical parameters of zooplankton in 2005 [4] at the project area are shown in the
Table 3.18.

 Table 3.18 THE ANALYTICAL RESULTS OF ZOOPLANKTON AT THE PROJECT AREA

                    Number of species (/ site( #5m3)
                                                                       Density (individual /m3)
      Group
                     R1         R2         R3         R4        R1          R2           R3         R4
Amphipoda            0           0          1          1           0            0             1      1.3
Chaetognata          3          2           3         3          6.7          1.6           1.9      4.0
Cladocera            1          1          0          1          6.7          1.6             -      2.0
Copepoda             5          7          11         14       326.2        979.2          614     1229
Decapoda             2          1           2         1          6.5          1.1           2.2      3.1
Larvae                                                        4296.8        514.6         432.3    714.5
Medusae                                                          3.8          3.2           4.1      5.1
Total                11         11         17         20      4646.8       1501.2        1055.6   1959.1
Diversity (Hs)      1.65       0.67       1.65       1.92
Source: RDCPSE, 2005

Above analytical results show that the diversity is lowest at the R2 site on Cai Tau river
where is planned for taking cooling water, because this area is polluted. It is clearly to
identify in the above analytical results (the NO2- is higher than allowable limit).
      Benthos [4]

The analytical results of benthos in December, 2005 are shown in Table 3.19.


        Table 3.19 ANALYTICAL RESULTS OF BENTHOS AT THE PROJECT AREA

                                      Number of species                   Density (individual /m2)

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          Group                        (/ site( 0,15m2)
                               R1        R2        R3        R4        R1        R2       R3      R4
  Crustacea                    1          0         2         2        27         0        20      13
  Polychaeta                   0          0         2         3        0         0        87      167
  Total                        1          0         4         5        27         0       107     180
  Diversity (Hs)                0         0       1.65      1.34
Source: RDCPSE, 2005

The above analytical result of benthos shows that at R1&R2 sites on Cai Tau River, the
benthic community is very poor. Especially, at the R2 site, where is planned to intake the
cooling water, the benthic community disappeared completely. The sediment of this area
(R2) has the high content of hydrocarbon. This may be this area is affected by the
wastewater from the residential area and Ngoc Sinh Fishery Processing Factory on canal
21.

    Aquacultural resources

According to the result from meeting between RDCPSE and Ca Mau Fishery Department
(June, 2002 and January, 2003), the aquacultural resource at canals/ rivers around the
project area (Ong Doc river, Trem river and Cai Tau river) is insignificant because of the
poor aquatic communities. As for Vo Doi specific forest, freshwater fish and shrimp are
rather abundant owing to the decayed cover in the melaleuca forest is a rich food source for
aquatic species.

3.3.3 Natural Ecological Conservations at the project area and the vicinity

At the Ca Mau Gas-Power-Fertilizer Complex, there is no any bird sanctuary or ecological
conservation area. However, in the radius of 10km, there is Vo Doi specific forest about 8.5-
9 km far from the project area.
Total area of Vo Doi specific forest (9o15'N, 104o55'E) is about 3,724 ha belonging to U Minh
Ha, Ca Mau province. This is the remained oldest melaleuca forest. Flora is mainly
Melaleuca cajuputi, Phramites karka, Saccharum arundinaceum... Animals are rather
abundant such as: wild pig (Sus scrofa), deer (Cervus unicolor), weasel, squirrel, python,
snake, turtle and other wild animals.


3.4     SOCIO-ECONOMIC CONDITION
3.4.1 Population [11]
Population of Khanh An commune accounting to 2005 was about 18,000 (Khanh An
People's Committee) consisting of mainly Kinh, Khmer and Chinese. Due to topography
condition, production activities and infrastructure, Ca Mau inhabitants concentrate at the
town, townlet, river confluence and along the canal banks. At the project area, inhabitants
concentrate at Cai Tau residential area (opposite to Gas-Power-Fertilizer Complex). Since
2001, inhabitants in the Gas-Power-Fertilizer Complex (hamlets 1, 3 and 6) had to move to
temporary resettlement area belonging to the K1 Cai Tau Prison area. Integrated situation of
population and labor distribution at hamlets 1, 3 and 6 is given in Table 3.20.



  Table 3.20        POPULATION AND LABOUR DISTRIBUTION AT HAMLETS 1, 3 AND 6

 No.                      Population situation                       Hamlet 1      Hamlet 3     Hamlet 6
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 No.                    Population situation                          Hamlet 1     Hamlet 3     Hamlet 6
  1      Number of people                                              1548         458         1156
  2      Number of people at labor-age                                 1049         281          694
  3      Total household                                                291          81          256
  4      Agriculture-forestry-fishing household                        260          79           214
  5      Industry-construction household                                 5            -           3
  6      Service household                                               11           -           34
  7      Other service activities                                       13           2            5
Source: People Committee of Khanh An village, U Minh District, 2001


3.4.2 Administrative boundary and future planning orientation

The Ca Mau Gas-Power-Fertilizer Complex is located at Khanh An commune, U Minh
district. Khanh An natural area is 5,065 ha, in which productive land area are 3,352 ha.
Khanh An commune has 10 hamlets ordered from 1 to 10. The power and fertilizer plants
are located at hamlets 1,3 and 6 next to residential area of hamlet 4.

According to information of Ca Mau Construction Department in December, 2005, the
scheme orientations of Khanh An commune are mainly Khanh An residential area, traffic
systems and Ca Mau Industrial Gas-Power-Fertilizer Complex. In present, Ca Mau province
has constructed road of 14 km length from Ca Mau city to Ca Mau Industrial Gas-Power-
Fertilizer Complex.

The new resettlement area is 1,080 ha that is planned to build at U Minh III farm-land far
away from the project area (Figure 3.4). This new resettlement area is divided into 918
separately portions for households with the model of city house, garden house, agricultural
land, school, entertainment area, etc. In fact, this area is still wild land where has not yet
construction activities.
In general, Ca Mau is undeveloped industrial province. So, the Ca Mau Gas-Power-Fertilizer
complex is the first and the largest heavy industrial area in the province's development
planning orientation from 2001 to 2010.

3.4.3 Agricultural activities

At the project area, yield of rice is very low (25-30 bushels/0.1 ha) where there are only
double rice crops. At the present time, due to taking sea water for aquaculture, there is only
one crop of autumn-summer). The spring-winter crop is changed to shrimp cultivation. At
present, one rice-crop and one shrimp-crop pattern is enlarging quickly, and the area of rice
cultivation curtails gradually. Since 2001, most of the rice area along Cai Tau river and Minh
Ha canal had changed to ecological shrimp development. Accounting to 2005, total shrimp-
crop area of Khanh An commune is 2,846 ha and the shrimp cultivated area is 557 ha. There
are 1,384 households feeding shrimps alternating with sea-perch, pointed-tailed goby
(Pseudapocryptes elongates), crab, etc. The area for double rice crops in the province
remains only 116 ha [11].

The area of fruit-trees, vegetables and crops highly increases because many households
used their house's pond edge and their boundary for cultivating. Due to the price of sugar-
cane in 2005 is higher than in the former years, household's difficulty is reduced by the
profit from sugar-cane.

Because of the bird flu at the beginning of 2005, a large number of infected poultries were
destroyed. This makes the proposed plan uncompleted.
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Achievements in 2005 of the people in Khanh An commune are as follows [11]:
-   The area of autumn-summer crop occupied 116 ha which concentrates at hamlet 6, 7
    and 8. The harvest was completed in September, 2005 with productivity of 6 tons/ ha.

-   The area of shrimp aquaculture occupied 2,846 ha. The plan of 2005 was completed.
    The average productivity is 60-80 kg/ha. The estimated productivity is 227 tons,
    equivalent with 70% of the plan.

-   There are 21 households with model of 30 millions/ha/year production and 6 households
    with shrimp-rice-fish model.

-   The organisation of producing at the resettlement area has not yet carried out, but the
    main remaining matters of land in the commune area were solved.

-   About the bird flu epidemic, two inoculations were conducted against the epidemic for
    7,847 poultries, gaining 100% compared with the surveyed data. The protection and
    prevention plan of bird-flu disease is available for the next period.

3.4.4 Industrial production activities

Ca Mau Gas-Power-Fertilizer complex is the biggest high technical industrial zone of Ca
Mau province that is constructed in Khanh An commune. It includes power plant, fertilizer
plant, gas distribution station and PM3 - Ca Mau gas pipeline system. In 2005, a processing
fishery factory named Ngoc Sinh has operated in the commune.

3.4.5 Infrastructure and transportation

3.4.5.1 Infrastructure
    Power supply

At present, the average quantity of electricity is 100 kwh/person.year, equivalent with 30%
the national level. It is estimated that electric capacity demand of Ca Mau province in 2005 is
about 59 MW and the 110kV stations of Ca Mau province will be supplied by 220 kV stations
arrived from Bac Lieu province in 2010 in order to supply stable electricity for Ca Mau.
Besides, in order to synchronize with the gas turbine thermo-electricity plant, a 220 kV
station will be built in Ca Mau in the period 2006 - 2010.
A transformer station at hamlet 10 was built by Management Board of the Southern grid A,
Khanh An commune with the power from 220 kW to 110 kW which is supplied for province's
activities. The area of transformer station is about 31,000 m2.
Ca Mau Power Department had completed pulling the low voltage power wire (1000m) from
T13 sluice to the new canal at hamlet 10 which is supplied for inhabitants of this area (over
25 households).

    Telecommunication
At present, Vinaphone, Mobiphone and Viettel waves are available at the project area. At
Khanh An, there are 483 telephones with average of 3.5 telephones/100 persons. The
telecommunication system serves well and provides much more information for commune
people [11].
    Water supply


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At present, Ca Mau Water Supply Company is studying for enlarging and upgrading the
water supply system of Ca Mau city. It is estimated that output capacity is 35,000 m3/day
(15,000 m3/day at present) from ODA fund of Italian government and contribute capital.

3.4.5.2 Transportation

      Road transportation

Before 2002, it seems to have no road transportation system from Ca Mau city to Khanh An
commune and waterway transportation is the main mean of the local people in this region.
However, since the site clearance and local people removal for Ca Mau gas-power-fertilizer
complex project (2001) is implemented, the People Committee of Ca Mau province has
carried out to construct a road of 6m in width along Minh Ha canal, connecting from Ca Mau
to U Minh district. In addition, Petrovietnam has cooperated with Ca Mau province to build a
new road of 14.5 km length from Ca Mau city to gas-power-fertilizer complex at Khanh An.
This project was approved in October 10th, 2005 and named "transportation system from Ca
Mau city to gas-power-fertilizer complex". The beginning of construction was announced in
December 10th, 2005 and it is planned to complete in 14 months.

      Waterway transportation [12]

Ca Mau has closed waterway system that is quite convenient for inter-provincial, inter-district
and internal transportations. However, during the exploitation, many banks along rivers and
canals have been eroded. Following are main internal waterway routes passing through
project area:
         Ca Mau city - Ong Doc river: 40 km length
         Ca Mau city - Ganh Hao - Bay Hap: 31.5 km length
         Ca Mau city - Dam Doi - Tam Giang - Nam Can: 71 km length
         Ca Mau city - Cai Tau - Tieu Dua: 51 km length

Diagram of main waterway systems from the project area to the nearby provinces is shown
in Figure 3.5.

At Khanh An commune, ferry boats arriving and leaving Khanh An commune are very
crowded. The number of boats passing Cai Tau confluence is given in Table 3.21 [13]

 Table 3.21 THE DAILY NUMBER OF PASSENGER BOATS IN CAI TAU CONFLUENCE -
                         KHANH AN VILLAGE COMMUNE

 No            Waterway route                 Quantity of return boat              Passengers/boat
  .                                                /day (boat)                       (passenger)
  1     Ca Mau – U Minh                                 30                               25
  2     Ca Mau – Thoi Binh                                30                               25
  3     Ca Mau – Thoi Binh                                 2                               35
  4     Ca Mau – Thoi Binh                                 2                               45
  5     Transport boat – other boats                      40                                -
Source: Management office of Wharf A, Ward I, Ca Mau city (2002)




3.4.6 Aquaculture

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According to statistical data of Ca Mau Fishery Department in 2005, the area and the yield of
fishery and shrimp aquaculture in U Minh district from 2000 to 2005 are shown in Table 3.22.
    Table 3.22 AREA AND YIELD OF FISHERY AQUACULTURE IN U MINH DISTRICT

 Parameter                        Unit      2000       2001        2002       2003       2004      2005
 Surface-water area for           ha       15,524     23,271      22,458     22,628     22,203    22,200
 fishery aquaculture
 Surface-water area for            ha       2,294      9,410      12,235     11,791     10,955    11,360
 shrimp aquaculture
 Yield of fishery                  ton     15,496     12,885      4,228       4,604      5,612    6,546
 aquaculture
 Yield of breeding fish            ton     15,300     11,692      2,129       2,256      3,500    3,910
 Yield of breeding shrimps         ton      196       1,193       2,100       2,348      2,112    2,636
Source: Ca Mau Fishery Department, 2005

The above statistical data shows that the conversion into fishery aquaculture structure most
popular occurred in 2001 & 2002. However, in 2005, the surface-water area for fishery and
shrimp aquaculture was reduced.
Project area is located in freshen-water zone, it is not the key aquacultural development area
of the Ca Mau province. The aquaculture area from Ong Doc estuary to Khanh An commune
(project area) is about 25,000 ha, occupying 10% in the total area of the commune [Ca Mau
Fishery Department]. Since 2001, Khanh An village has implemented agricultural structure
changes from double rice crops to one shrimp and one rice crops in large area. This got
supports from local people. Until now, the progress of structural conversion is quite fast and
the economic effect is quite good. To 2001, there are 2,391ha converted in the whole village,
occupying 71.33% in the total cultivated area of the commune. The productivity of shrimp
farming in 2001 was 430.38 tons and the average productivity was 180 kg/ha/year.
According to the report of Ca Mau Fishery Department in 2005, in Khanh An commune the
aquacultural yield is not high, estimated only about 60-80 kg/ha in 2,800 ha of cultivated
area.

3.4.7 Health and Education [11]
    Health: At Khanh An commune, there are one medical station with 1 doctor, 3
    physicians, 1 pharmacist and 3 nurses (1 midwife nurse) with 20 patient beds. According
    to Department of Health of Ca Mau, existing diseases at the project area are mainly
    bronchitis, pneumonia, diarrhea, petechial fever and typhoid.
    Education: Khanh An commune has 9 schools with 39 rooms and 106 teachers. The
    total pupils are 2,258 in the year 2005-2006 [People Committee of Khanh An commune]
    including:
        + Secondary school: 882 pupils (reduce 190 pupils than last year)
        + Primary school: 1,113 pupils (reduce 168 pupils than last year)
        + Garden school: 263 pupils (increase 33 pupils than last year)

3.4.8 Cultural relics, archaeology and tourism
Ca Mau has many natural conservation areas with many beauty landscapes, bird
sanctuaries, melaleuca and mangrove forests... attracting ecological tourists. However, due
to the disadvantage of transportation, Ca Mau tourism hasn't developed yet. At the project
area, there is CaoDaism pagoda - Cuu Linh Chau, which is situated very close to Cai Tau
confluence. It was removed before constructing gas-power-fertilizer complex.
3.4.9 Existing pollution sources before having project

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▪   Domestic waste

At the project area, the hygiene situation of Cai Tau residential area is very poor. There is a
lot of garbage along the canal banks. Rubbish is discharged directly into the canals where a
lot of nylon bags and fruit peels are drifted. Along Ong Doc river-banks, there are some
existing temporary domestic waste landfills caused pollution to water source.

Existing waste treatment of Ca Mau province:
    -   At present, the waste treatment system is unavailable in the province. The solid
        domestic wastes from the fishery processing factories are discharged directly into
        river.
    -   In province, there is only one domestic waste landfill located in Hamlet 1, An Xuyen
        commune and on national highway No. 63 in the suburb of Ca Mau city, where all
        domestic wastes are collected and transported by road transportation.
    Industrial production activities

In Khanh An commune, Ngoc Sinh Processing Fishery Factory is operating. Its wastewater
is discharged directly to the canal 21 of Cai Tau river. This has caused water pollution for
this canal and Cai Tau river in May, 2005. Khanh An commune People Committee and
Department of Natural Resource and Environment had warned and administrative finned.
Ngoc Sinh factory promised to make good and a waste treatment system has been built .

    Boats/ships activities

Boat/ship density in Ca Mau province is very high. Moreover, the means (barge, passenger
boat, transportation boat, wooden barge, high speed canoe and motorized sampan, etc.)
and boat's capacities are quite difference, especially steersmen were trained in a short
training course or without any course. So, the potential risk of boat/ship collision is very high.
In addition, a significant amount of lubricant, residue oil are discharged from dense boats
activities to the rivers/canals that causes water pollution and destroys aquatic environment.

    Aquacultural activities
Wastewater and disposal mud from shrimp ponds are pollution sources to water quality of
surrounding areas. Especially, at the shrimp industrial cultural areas along Ong Doc river
where has no disposal mud treatment system, but were discharged directly into the river. In
addition, the utilization of food and preventive and protection medicine for aquacultural
development had partly caused water pollution. At Ong Doc estuary, wastewater from fish
powder processing factories, sea product processing factories, fish source processing
factories... were discharged directly into Ong Doc river causing serious pollution to the
aquatic enviroment.
It is noted that before having presence of Ca Mau gas-power-fertilizer complex (2000-2003),
there are some existing diseases causing shrimp-death at aquacultural areas along the river
banks of Ong Doc, Minh Ha, Trem and Cai Tau river/canals. This originates from the
unprompted pattern changed from rice field to shrimp pond, the polluted water or the
disease. Therefore, this phenomenon will continue happening after Gas-power-fertilizer
complex coming into operation. It is necessary to have cooperation between Department of
Natural Resource and Environment, Department of Fisheries and Project Management
Board in order to verify clearly causes/ reasons, not accuse from power plant operation.
Wastewater generated from power plants is always treated and managed according to
discharge permits, which are issued by Ministry of Natural Resource and Environment.


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    U Minh melaleuca forest fire [14]

In the dry season 2002, several serious forest fire accidents were happened at U Minh
melaleuca forest. Forest fire had caused great damages to U Minh old malaleuca forest. In
which more than 4,600 ha U Minh Ha forest area was fired and 3,800 ha was completely
destroyed. More than 4,000 ha primary U Minh Thuong melaleuca forest was fired.

In the recent years, dry climate, long lasting hot sunshine, forest area is drought sooner,
water in canal system is not adequate for transportation and fire fighting in time. In the
melaleuca forest, there is a thick vegetation layer, so fire is easy to spread out a large area
and causes big fire. On the other hand, the custom of getting honey, illegal hunting birds and
fish in the melaleuca forest and careless fire use is always a threaten in the dry season. At
present, measures of fighting protection and prevention are not secure that forest fire will not
happen in the coming years.

In recent years, local authorities paid attention to the forest fire fighting and prevention works
together with the favourable climate (heavy rain), the forest fires occurred not so many. In
2002, in the whole province, there are 66 forest fires which fired area are about 4,423 ha. In
the dry season in 2003-2004, there are 3 forest fires that damage 3,200 m2 forest.

The happening of fire forest in Ca Mau province in 2005 [3] is shown in Table 3.23.

            Table 3.23 FIRE FOREST ACCIDENTS AT THE BEGINNING OF 2005

                                            Area of                                             Reasons
     Time              Location            damaged                Solution
                                          forest (ha)                                           (if defined)

                 Tran Van Thoi                           -Forest-fighting means:
                                                                                        Careless smoking
                 forest fire, sub-                       high capacity pumps
 14/03/2005                                  0.16                                       while tidying up
                 area 051
                                                         -Fire-fighting force: 50
                                                         persons
                  Tran Van Thoi                          Means and fire-fighting
                  forest fire, sub-            9         forces at site                 -
                  area 50
 15/04/2005
                  Vo Doi Forestry                        Means and fire-fighting
                  Station of                             forces on the spot
                                              10                                        -
                  special-use
                  forest
Source: Existing environment of Ca Mau province, 2005




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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)        55




Section        4.
POTENTIAL ENVIRONMENTAL
IMPACT ASSESSMENT
As mentioned in chapter 2, Ca Mau 2 power plant is carried out on basic of two times
multiple of the Ca Mau 1 power plant. It was constructed in area of 10ha, belonging to the
land of proposed fertilizer plant. Due to capacity and configuration of Ca Mau 2 power plant
is similar to Ca Mau 1 power plant, therefore the environmental assessment for the Ca Mau
2 power plant will similar to Ca Mau 1 power plant.

4.1 CONSTRUCTION, INSTALLATION AND COMMISSION PHASES
4.1.1 Main sources of environmental impacts
Due to area of the Ca Mau 2 power plant had been cleared, vegetation cover was removed
and it was filled up to 1.5m since 2002, so in present, the site foundation needs to
consolidate and treat only. The activities related to construct temporary port for transporting
super size and super weight equipment and imported DO jetty for the two power plants were
mentioned in EIA report of Ca Mau 1. So the main polluted sources in construction and
installation/commission processes of Ca Mau 2 power plant are summarized in table 4.1.
 Table 4.1 MAIN SOURCES OF ENVIRONMENTAL IMPACTS DURING COSTRUCTION/
                  ISTALLATION AND COMMISSIONING PHASES

Environment                     Polluted source                                Pollutants            Level
Air               -Filling up and consolidating foundation;
                                                                       -Dust, CO, NOx, SOx,
                  -Equipment installation
                                                                       VOC, CH4,
                  -Operation of constructive equipment;
                                                                       Hydrocarbon
                  -Painting exposed surface
                  -Equipment commissioning and Testing
Water             - Piling                                             -Sludge
                  -Embankment building around the plant                -Liquid wastes
                  -Transportation of construction material             -Solid wastes
                  and equipment                                        -Alum water: Fe2+, Al3+.
                  -Boat/ship activities
Soil              -Filling up and consolidating foundation             -Construction wastes
                  -Dredged sludge disposal                             -Domestic sewage
                  -Construction wastes disposal                        -Hazardous wastes
                  -Domestic sewage disposal
Biology           -Piling                                  -Sludge
                  -Embankment building around the plant    -Liquid wastes
                  -Transportation of construction material -Solid wastes
                  and equipment
                  -Boat/ship activities
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4.1.2 Impact on physical environment

4.1.2.1 Air quality
Dust
Due to urgent demand about construction progress of the both plants 1&2, so many works
will be deployed at the same time. The process to conduct with works: excavating, filling up,
sand pump, consolidating foundation, building works used brick, stone, steel, etc… will
generate a significant quantity of dust. According to the analyzed results of dust content at
the project area in December 2005, the dust content at project area is higher than allowable
standard due to consolidating foundation activities for the Ca Mau 1 power plant.

Above construction activities together with the operations of vehicles transporting sand from
sand unload sites to filling up sites will generate large dust at construction area and maybe
affect to Cai Tau residential and resettlement area. Effect duration from above activities will
last appropriately 16 months.

Dust also generates from polishing, welding and painting activities during installation of gas
turbine units, fuel gas supplying pipeline, cooling tower and storage tanks. The fine dusts
and paint vapor might affect to respiratory organs of labors working directly in the
construction site and cause asthma, pneumonia and bronchitis disease.

In brief, dust generated from the power plant construction and installation activities will cause
direct impacts on the labor force in project area and indirect affects on 300 households in the
resettlement area and Cai Tau residential area. Impact level is considered as moderate in
the first year and then reduces gradually to minor level in the following years of construction
and installation phase.

Emissions

Emission from construction equipment

Operation of construction equipment will discharge a significant quantity of different emission
gases into environment depending on the transportation ways and operation of each
equipment, including:

    Activities of sand backfill and construction material transportation: Due to the project
    area can not satisfy construction material demand, so materials such as: sand, cement,
    and stone will be transported from An Giang, Kien Giang and Can Tho provinces. As
    calculation, backfill sand is transported to unload site by barge and then it will be
    transported to the consolidating foundation area by trucks of 10 – 12 tons (7m3).
    Depending on the operating capacity of construction equipment, used fuel is estimated of
    60 litters DO/shift for dredgers and trucks and 80 – 90 litters DO/shift for heavy machines
    such as rammer, grader, digger and pile driver. This work is completed in 16 months.

    Transportation and installation activities: installation process of equipment units and
    utility system has to use heavy cranes, equipment installing machines, lorries for the
    power plant. It is estimated that 5 cranes, 10 trucks, 2 air compressors will be used for
    transportation. Period for equipment installation is about 18 months.

According to the quick assessment method of World Health Organization WHO 1993 [15],
estimation emission volume of diesel engines used in the construction period is summarized
in table 4.2.

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  Table 4.2 ESTIMATION EMISSION VOLUME FROM OPERATION OF CONSTRUCTION
             EQUIPMENT IN CONSTRUCTION AND INSTALLATION PHASE

Operation              Amount       Used       TSPb      COc                               SO2a       NOxd      VOCe
                       (piece)    DO (ton)     (Ton)    (Ton)                              (Ton)      (Ton)     (Ton)
1. Operation of consolidating foundation (16 months)
Dredger                   14           565      2.43     7.91                              0.034     39.55      2.26
Pile driver               10           538      2.31     7.53                              0.032     37.66      2.15
End dump lorry            70         2.822    12.11     39.51                              0.170     197.54     11.29
Bulldozer                 10           538      2.31     7.53                              0.032     37.66      2.15
All kind of rammers        7           376      1.62     5.26                              0.023     26.32      1.50
KOBE digger               11           591      2.54     8.27                              0.036     41.37      2.36
              Total 1                         23.32     76.01                              0.327     380.10     21.71
2. Transportation and installation power plant (18 months)
Air compressor             2           151       0.65     2.11                             0.009      10.57     0.60
Crane                      5           302       1.30     4.23                             0.018      21.14     1.21
Truck                     10           454       1.95     6.36                             0.027      31.78     1.82
              Total 2                            3.25    10.59                             0.045      52.92     3.03

According to above data shows emission in the filling up and consolidation period is the most
considerable. However, because the construction equipment operating at ventilated rural
plain area so the emission will be dispersed quickly and impact level is considered as small
and only limited within the project area.

Emission from commissioning phase
In commissioning phase, Ca Mau 2 power plant will be tested by combined cycle in about 40
days by natural gas and DO fuel under loading regime of 100%. Emission volume and
component of exhausted gas from stacks are presented in table 4.3.

   Table 4.3 COMPONENTS AND EMISSION VOLUME IN TESTING PROCESS FOR CA
                           MAU 2 POWER PLANT

   Testing regime*           Flow rate           Time            ToC                       Pollutant content
                               (m3/s)            (Day)                                          (mg/m3)
                                                                                CO                NOx             SOx
  Testing by natural gas
  Full loading 100%      674       30                             97            12.5               51.3            -
                    TCVN 7440-2005                                              180*               210            252
  Testing by DO fuel
  Full loading 100%      736       10                            138            12.5               149.8          277
                    TCVN 7440-2005                                              180*                504           420
Note:   * Apply: TCVN 6993:2001 with KCN=0.6 (A level technology)
         Karea=1.2 (industrial zone in pure rural area)
                                                                                     3
         Q3 corresponding to discharge sources with released flow rate > or = 20,000m /h

In the first test, a significant black smoke will generate including dust and undesirable
products such as lubricants adhered to surface of heatproof equipment. In case of testing by
natural gas, volume of CO and NOx in emission gas is much lower (4.1 to 14.4 times) than
Vietnamese standard TCVN 7440:2005.
In case of testing by DO fuel, volume of SOx, NOx in emission gas are still lower 1.5 to 3.4
times than TCVN 7440:2005. Moreover, as planning, the commissioning and testing duration


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run mainly by natural gas, DO testing duration is only 10 days. So impact level in this case is
considered as small level.

4.1.2.2 Noise and vibration
The same with construction and installation equipment of the Ca Mau 1 power plant, the
operation of heavy machines (Pile driver, compressor, crane and concrete mixer. etc.) will
generate noise which will directly affect to workers working in project area and adjacent
areas. Especially, the noise generated from pile driver (75dB) is not great in comparison with
the noise generated from bulldozer but stretched, so it makes uncomfortable for local
people, especially at night time.
Moreover, the direct driving a great quantity of concrete pile for foundation consolidating to
the depth of 60 meters not only generated noise but also cause strong vibrating within radius
of 200 meters in the project area.
Thus, noise generated from construction equipment ranging within 75 – 93 dB will directly
affect to health of construction workers and residents living in Cai Tau area within radius of
200 meters, especially at night. Impacts level is assessed as small but uninterrupted during
working process.

4.1.2.3 Impacts on water quality

Ca Mau 1 & 2 power plant project is located next to Cai Tau confluence area of three rivers
(Cai Tau, Trem and Doc river). Due to the road system in the project area is not developed,
therefore all transportation activities of construction material and equipment units of the
power plan must be transported by waterway system. Therefore many construction activities
of the project may affect to water quality including:
    Transportation activities for construction material and super size, super weight
    equipment;
    Dredge activities and expanding port area;
    Piling for consolidating foundation.
    Domestic wastewater from camps of construction workers.

Above activities will affect to environment as follows:
    Make changes local current regime due to dredging and expanding the port area. The
    excavating port too deep will make the current from Trem River increased toward the
    port.
    Increase alum washing out process at the beginning of rainy season due to piling and
    excavating activities. Moreover, during foundation consolidation process, vacuum pump
    of alum water to the adjacent river/canal will make decreasing pH of Cai Tau, Trem and
    Doc rivers (pH value in the range of 3.81 to 4.25) and increased toxicants content such
    as H+, Al+3, Fe+2, SO4-2.
    Disturb water environment due to activities of expanding port and boat activities for
    equipment and material transporting and increase suspend solid (TSS) and pollutants in
    the sediment at Cai Tau confluence area. The affected area within distance of 1 to 3
    kilometers from dredging site with the impact level is considered as medium during
    construction phase.
    Hydrotest water: hydrotesting process of pipeline system will be carried out at each
    section so the process will be simply so much and save a lot of testing water. As planed,
    pipeline hydrotesting process will use mineral water and tank hydrotesting will use
    portable water supplied by Ca Mau Water Supply Company and no chemical will be
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    used. Maximum water used for hydrotest is about 5,000m3 for oil storage tank. After
    testing, all hydrotested water will be discharged to rainy drainage system of the plant to
    the Cai Tau river and impact on surrounding environment is insignificant.
    Domestic wastewater generated from construction area will be discharged through the
    hygienic septic tanks system. During the plant construction phase, there are about 1500
    to 2000 persons working within 28 months. Estimated domestic wastewater quantity in
    the construction/installation phases is about 189,000 to 252,000 tons. However,
    wastewater from the camp area of construction workers located outside the plant area
    must be discharged through the temporary toilet system next to cannel/rivers. So it can
    cause organic pollution and water-born diseases such as: cholera, typhoid, dysentery.

Therefore when undertaking all construction activities of the CM1 and CM2 power plants at
the same time will reduce significant pH value of Cai Tau, Ong Doc, Trem rivers. The alum
pollution level due to construction activities of the power plant to water environment at Cai
Tau confluence is considered as medium in rainy season (from May to October) in the two
first years of construction phase and as small in the following year for the adjacent areas of
project in the range of 5 to 7 kilometers on the downstream of Cai Tau and Ong Doc rivers.

4.1.2.4 Impacts on soil quality

    Change of soil structure
Due to geological characteristics at the plant area, there is a weak soil layer with a thickness
of 17 – 20 meters, therefore all the power plant area must be filled up and consolidated to
the elevation of +1.97 to +2.84 meters by pre-loading combined to vacuum compressing
method. In the area where super weight equipment will be installed such as transformer
units, gas turbines, cooling tower and storage tanks, it must be piled the concrete piles to
the depth of 60meters. Total of the concrete piles must be piled about 329 concrete piles
with 100m in length and 49,000m of cram concrete piles. Above construction activities
cause strong disturbance to the soil environment, direct affect to 10 ha of agricultural area
and change of soil structure from wetland (high porosity, high compressibility, high melt
ability) to construction soil (low porosity, low compressibility,…).

    Soil pollution due to solid wastes disposal
Non-hazardous solid wastes generated during construction and installation phase include:
metal, plastic, small amount of other materials from construction phase and used packaging
from installation and commissioning process.
Hazardous wastes are paints, solvent, welding rods, engine and waste oil are estimated as
very low. It is noted that in the rainy season, the heavy rain may wash out contaminants on
surface to water source and the construction in rainy season will be more complicated and
the incident risk may be increased at different levels.
According to the criteria of Viet Nam Hygiene and Public Health, quantity of domestic solid
waste generated during construction phase (28 months) is estimated in range from 1,071 to
1,428 tons. All of them will be collected and treated by Ca Mau Urban Hygiene Company to
limit soil pollution.
Briefly, the project activities during the site preparation, construction and installation phase
will lose surface organic soil, decrease considerably agricultural land area (10 ha), change
of land-use, soil structure and enhance alum leakage ability. However, the land-use purpose
of project area is converted from agricultural land to industrial land. Therefore, impact level
on soil environment is assessed as moderate during construction phase.

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4.1.3 Impacts on biological environment

Due to the plant ground was cleared and surface soil layer was removed since 2002, so at
present, the Ca Mau 2 Power plant site has filled up by sand and the vegetation cover near
the plant area is not diversity. Therefore, the plant constructive activities are not affected to
the terrestrial ecosystem.
Expanding port activities to serve for the both CM1 and CM2 plants will cause sediment
disturbance at Cai Tau river area, that cause affect on aquatic ecosystem especially affect
to bottom fauna species. However, according to the analyzed results in environmental
baseline report, which was carried out at the project area in 2002 showed that the aquatic
species is very poor. Thus, impact level on the aquatic ecosystem during construction phase
is assessed as low to moderate.

4.1.4 Interactions
    Coordination between investor and constructors
The progress rate of Ca Mau 2 power plant is very urgent. Beside, the constructor of the Ca
Mau 1 power plant is also the constructor of the CM2 power plant, therefore at the same
time, both CM1 and CM2 power plant are constructed so the reasonable arrangement of
execution equipment and coordinate the work between the both plants are necessary.

The management of constructional works at the same time in the same industrial units will
not avoid the difficulties about manpower and material power sources. Therefore, if there is
not synchronous coordination between construction units as well as constructors and sub-
constructors, that will generate of complicated problems. Beside, the presence of large
labors coming from different areas will cause disturbance living condition of local people
such as increasing cost of living, as well as raising some conflicts between workers and
local residents.

    Activities of local boat
The project area is surrounded by large rivers as Cai Tau, Trem and Ong Doc, so before
having the gas-power-fertilizer complex, the boat density was busy including high speed
passenger boats, barges, oil and petrol transportation ships. According to statistical of A
wharf management board of Ca Mau city, everyday the quantity of passenger boats (25 – 45
persons/boat) and constructive material, oil and petrol transportation ships is about 104
boats. In which the passenger boats are 66 boats/day with berthing frequency of 30
minutes. Furthermore, due to high quantity of local residential boats from Cai Tau area and
inland areas to Cai Tau market trading (at least, each household has one boat); therefore
boat density in this area increase highly. Moreover, due to road traffic system has not yet
developed, so all transportation of agricultural products and constructive material and traffic
of local residents are by waterway means. It is noted that, almost owners of traffic means do
not obey strictly waterway traffic regulations, especially speedy boats and boats, so potential
boat/ship collision risk is relatively high.
As development the revised Ca Mau power plant project, above boat/ship operations will
cause an interactive effect with barges/boats back and forth the port area. And their
presence as well as ships for supply and constructive material transportation of the project
will also cause increasing boat density, which is already crowded at this area. Constructive
activities will obstruct partly the living of local resident and make increasing of potential risk
of ship collision between transportation boats and big passenger boats, speed – canoes and
constructive barges or between ships with port works, if lacking cooperation of project
management board and local authorities as well as ship owners don’t obey the signal buoy
system.
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4.2     OPERATION PHASE

4.2.1 Main source of environmental impacts

In operation phase of the power plant, main activities can effect to environment including:
- Operation of gas turbine using natural gas or DO;
- Operation of cooling tower;
- Cooling water intake and discharge;
- Waste disposal.

Above activities will generate emission gases, wastewater and solid waste including:
−   Emission gases from HRSG contain NOx, CO and in case of using DO fuel, it contains
    more SOx. Emission gases emit to environment through the main stack of 40m height;
−   Wastewaters including: regular discharge cooling water with highest temperature is
    about 35oC and in case of tail gas incident (rarely occur) the highest temperature is 40oC;
    discharge water from boiler is demineralization one containing small content of
    phosphate, ammoniac and hydrazine which are regular routed into temperature
    exchange tower and then together discharge with cooling water; and other industrial
    wastewaters;
−   Other solid wastes including: industrial waste, mud waste from wastewater treatment
    system, oil sludge waste and domestic waste.
If there are not reasonable management or unreasonable disposal for these pollutants, that
will cause affect to environment quality.


4.2.2 Impacts on physical environment

4.2.2.1Air quality

Ambient air quality of the power plant may be affected by emission gases from operation of
turbine in the plant and dust, steam from operation of cooling tower. Besides, noise
generated from the plant also affects to workers working in the plant and local residents
living near the plant.

1. Impacts of regular emision gases from turbines

Similar to the configuration of Ca Mau 1 power plant, Ca Mau 2 power plant includes two
gas turbines and one steam turbine that designed to burn both natural gas and DO fuel. The
main fuel for operation of the power plant is natural gas from PM3-CAA and Cai Nuoc
blocks. When the gas supply source is interrupted, the power plant will use imported DO
fuel with highest content of sulphure of 0.5%wt and using quantity of about 108.5 tons/hour.

    Load and content of regular emission gases from gas turbines

Emission gases generated from operation of the plant will discharge to the environment
through two main stacks of 40m height. Emission gases generated from natural gas burning
is mainly NOx, CO and a small quantity of unburned hydrocarbon. In case of DO burning,
the mainly emission gases consist of NOx, SO2, CO and dust (ash). Estimating load and
content of regular emission gases from the combine cycle power plant through main stack
are ssummarized in table 4.4.


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 Table 4.4      LOADS AND CONTENT OF REGULAR EMISSION GASES THROUGH THE
                         STACK OF CA MAU 2 POWER PLANT

                Parameter                         Unit            Emission gases                  TCVN
                                                              Gas burning    Do burning         7440:2005
Stack coordinate                                              X=1021746,52; Y=396813
                                                              X=1021746,52; Y=396853
Stack height                                   m                          40
Stack diameter                                 m                         6,5
Emission gas flow rate                         Nm3/s             674            736
                                               o
Emission gases temperature                      C                 97            138
Emission gas velocity                          m/s                20             21
Emission gas component
SOx                                            mg/Nm3              0.85            277            252a
                                                                                                  420b
NOx                                            mg/Nm3              51.3           149.8           210a
                                                                                                  504b
CO                                             mg/Nm3              12.5            12.5           180c
Dust                                           mg/Nm3              5.0             10.0           42a
                                                                                                  126b
Note:            DO with sulfur content of 0.5%kl.
                 a- Discharge standard in case of using gas fuel
                 b- Discharge standard in case of using oil fuel
                 c- Comply TCVN 6993-2001

In both cases, natural and DO burning, emission gas components at stack outlet are lower
than dicharge standard of thermo-electric industrial branch TCVN 7440:2005 (for NOx, SOx
and dust) and TCVN 6993:2001 (for CO).

Besides, to assess the environmental combinative impacts of both plants 1&2, quantity of
regular emission gases from stacks of the Power plant 1 will be also calculated in emission
gas dispersion modeling.

   Selected options for calculating dispersion ability of air emission

Ca Mau 2 power plant is located next to Ca Mau 1 power plant, so following options are
selected for calculating dispersion ability of air emission:
    Option 1: Calculation of dispersion ability of air emission from Ca Mau 2 combined cycle
    power plant through two main stacks of 40m height in case of 100% natural gas burning;
    Option 2: Caculation of dispersion ability of air emission from Ca Mau 2 combined cycle
    power plant through two main stacks of 40m height in case of using 100% DO fuel with
    maximum sulphur content of 0.5%wt
    Option 3: Combined calculation of dispersion ability of air emission from CM2 combined
    cycle power plant through two main stacks of 40m in height and CM1 combined cycle
    power plant through two main stacks of 40m height in case of using 100% natural gas;
    Option 4: Combined calculation of dispersion ability of air emission from CM2 combined
    cycle power plant through two main stacks of 40m height and CM1 combined cycle
    power plant through two main stacks of 40m height in case of using 100% DO fuel with
    maximum sulphur content of about 0.5%wt.




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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)       63


   Modeling for calculating of regular air emission dispersion ability
Air emission dispersion modeling ISC- ST3 – version 3.2 (The Industrial Source Complex
Short-Term) is used as calculating dispersion ability of regular air emissions in the plant.
This modeling established by United State Environment Protection Association (USEPA) is
used to determine pollutant contents from regular emission source, stacks, area and
uncovered tanks.ect. It was established basing on the co-ordination of different dispersion
modeling algorithms to assess impacts on air quality of emission gases. The basic principal
of modeling is Gaussian equation (Appendix 2).
ISCST3 modeling uses meteorological data for each hour to calculate the raising, moving,
dispersion and accumulation of air column in a specific area. The modeling will calculate
content or accumulation for each discharge source or receive source for each input
meteorological data for each hour and average meteorological data for short-term or all of
stage.
Before running specific options, this modeling has always been tested with specific sample
case (same input data running same discharged modeling) to determine modeling accuracy.
In case output result of testing running is in accordance with the sample result, this proves
that air dispersion modeling has high accuracy. In practical, ISC-ST3 modeling version 3.2
using in RDCPSE is American commerce one with high accuracy. This is acknowledged by
all over the world and using it to calculate air emission dispersion for discharge sources and
area. In Vietnam, this modeling is used for calculation air emission dispersion for most of key
projects such as Dung Quat petroleum refinery plant, Phu My Fertilizer plant & Power plant
complex, Dinh Co Gas processing plant, Ba Ria power plant, Dinh Co – Ba Ria - Phu My
gas distribution plant, Thi Vai LPG Terminal, CM1 Power plant...
To compare with air emission dispersion results at the power plant which was modelised in
detail EIA report for Ca Mau power plant (approved on april/2005), in this report has used
meteorological data (temperature, wind velocity, wind direction, cover level, sunshine)
recorded at Ca Mau meteorological station in 4 times/day within 1998-2000 but these data
were imitative calculated for 24 hours/day by the Southern meteorological station.
Especially, solar radiation data used for calculating atmospheric stability and disturbance is
based on the data recorded at Can Tho meteorological station (which was chosen for
calculating the solar radiation for all of Cuu Long river delta area by the Southern
meterological station)
In calculation process, topography factor and elevation of neighboring buildings have been
considered . But due to the specific charateristics of the power plant area is a plain region,
there are not obstacles here (building, mountain, hill .ect.). therefore, the modeling
calculation is only considered to elevation of ambient building of the plant. The height and
distance of ambient buildings of Ca Mau 2 power plant to the main stacks are calculated in
air emission dispersion modeling are shown in table 4.5:

Table 4.5 THE HEIGHT AND DISTANCE OF AMBIENT BUILDINGS TO THE MAIN STACK
                         OF CA MAU 2 POWER PLANT

 No.          Ambient building                 coordinate          Height (m)      Distance to the main
                                                                                        stack (m)
  2     Cooling tower                       X=1021772.29              15.18               18.70
                                            Y= 3966777.61
  3     Fuel tank 1                         X=1021799.79               17                   53.18
                                             Y=396959.10
        Fuel tank 2                         X=1021741.79               17                   53.18
                                            Y= 396959.10
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Ground air emission content was forcasted for a range of wind velocity that corresponds to
each asmopheric stability and a real set of mixing height. All of wind direction was modeled
to calculate variation of air emission plume corresponding to different wind directions.

   Modeling results

The result of air emission dispersion modeling of the CM 2 power plant and combination
with the emisson gas of the CM 1 plant will be assessed based on TCVN 5937-1995 –
maximum allowable concentration of some pollutants in ambient atmosphere is summarized
in tables 4.6 & 4.7.

 Table 4.6 MAXIMUM AVERAGE GROUND CONCENTRATION OF POLLUTANTS WHEN
  RUNNING FOR CA MAU 2 POWER PLANT FOLLOW OPTION 1&2 – WITH OBSTACLE
    Stack              Average 1 hour                     Average 24 hours                      Average year
                 Maximum Distance Main           Maximum Distance          Main       Maximum Distance        Main
                  content     (m)     directio    content       (m)       direction    content        (m)    direction
                        3
                  (μg/m )                n              3
                                                  (μg/m )
                                                                                             3
                                                                                        (μg/m )
Option 1: CM 2 power plant using 100% natural gas
SO2
1                   0.234    1616.9      SE         0.083      3179.4     W - SW           0.009    4278.6     E-NE
2                   0.233    1593.1      SE         0.084      3219.4     W - SW           0.009    4250.3     E-NE
Both                0.467    1604.9      SE         0.167      3199.4     W - SW           0.018    4264.4     E-NE
TCVN 5937:1995        500                             300
NOx
1                  14.936    1616.9      SE         5.288      3179.4     W - SW           0.588    4278.6     E-NE
2                  14.907    1593.1      SE         5.363      3219.4     W - SW           0.587    4250.3     E-NE
Both               29.844    1604.9      SE        10.651      3199.4     W - SW           1.175    4264.4     E-NE
TCVN 5937:1995        400                             100
CO
1                   3.639    1616.9      SE         1.288      3179.4     W - SW           0.143    4278.6     E-NE
2                   3.632    1593.1      SE         1.306      3219.4     W - SW           0.143    4250.3     E-NE
The both            7.270    1604.9      SE         2.595      3199.4     W - SW           0.286    4264.4     E-NE
TCVN 5937:1995     40.000                           5.000                                      -
Suspended dust
1                   1.459    1616.9      SE         0.517      3179.4     W - SW          0.0575    4278.6     E-NE
2                   1.457    1593.1      SE         0.524      3219.4     W - SW          0.0574    4250.3     E-NE
The both            2.917    1604.9      SE         1.041      3199.4     W - SW           0.114    4264.4     E-NE
TCVN 5937:1995        300                             200                                      -
Option 2: CM2 power plant using 100% DO as fuel
SO2
1                  75.158    1958.7    South       18.090      3558.6        South         2.041    4278.6     E-NE
2                  74.759    1959.6    South       17.865      4358.2        South         2.032    4250.3     E-NE
The both          149.917    1959.0    South       35.565      3558.8        South         4.072    4264.4     E-NE
TCVN 5937:1995        500                             300
NOx
1                  40.070    1958.7    South        9.644      3558.6        North         1.088    4278.6     E-NE
2                  39.856    1959.6    South        9.524      4358.2        North         1.083    4250.3     E-NE
The both           79.926    1959.0    South       18.961      3558.8        North         2.171    4264.4     E-NE
TCVN 5937:1995        400                             100
CO
1                   3.344    1958.7    South        0.805      3558.6        South         0.091    4278.6     E-NE
2                   3.326    1959.6    South        0.795      4358.2        South         0.090    4250.3     E-NE
The both            6.670    1959.0    South        1.582      3558.8        South         0.181    4264.4     E-NE
TCVN 5937:1995     40.000                           5.000                             -
Dust
1                   2.713    1958.7   South         0.653      3558.6        South         5.412    4278.6   E-NE
2                   2.699    1959.6   South         0.645      4358.2        South         0.073    4250.3   E-NE
The both            5.412    1959.0   South         1.284      3558.8        South         0.147    4264,4   E-NE
TCVN 5937:1995        300                             200                                      -
Note:       - SE: South East        W-SW: West- South West
            - E-SE: East-South East
            - Using DO, Sulfur concentration: 0,5%wt



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    Table 4.7 MAXIMUM AVERAGE GROUND CONCENTRATION OF POLLUTANTS WHEN
    RUNNING FOR THE BOTH PLANT 1&2 FOLLOWING OPTION 3&4 – WITH OBSTACLE

     Stack            Average 1 hour                    Average 24 hours                         Average year
                 Maximum    Distance     Main      Maximum    Distance      Main      Maximum       Distance        Main
                  content      (m)     direction    content      (m)     dispersion    content         (m)        direction
                 (μg/m3)                                                  direction   (μg/m3)
                                                   (μg/m3)
Option 3: CM2 & CM1 power plants using 100% natural gas
SO2              0.911 1775.8 S-SE        0.331 3774.6      South                       0.030       4020.2         West
TCVN 5937:1995     500                      300
NOx             58.180 1775.8 S-SE 21.110 3774.6            South                       1.924       4020.2         West
TCVN 5937:1995     400                      100
CO              14.174 1775.8 S-SE        5.389 3774.6      South                      0.469        4020.2         West
TCVN 5937:1995 40.000                     5.000                                            -
Dust             5.686 1775.8 S-SE        2.063 3774.6      South                      0.188       4020.2          West
TCVN 5937:1995     300                      200
Option 4: CM2 & CM1 power plants using 100% DO as fuel
SO2            288.587  1774.6 South 74.266 3774.6          South                      6.825       4020.2          West
TCVN 5937:1995     500                      300
NOx            153.856  1774.6 South 39.594 3774.6          South                      3.639       4020.2          West
TCVN 5937:1995     400                      100
CO             12.839 1774.6 South        3.304 3774.6      South                      0.304       4020.2          West
TCVN 5937:1995 40.000                     5.000                                         -
           Dus 10.418   1774.6 South      2.681 3774.6      South                      0.246       4020.2          West
TCVN 5937:1995     300                      200
Note: - S-SE: South-South East
       - Burning by DO, Highest sulphur concentration: 0,5%wt

     Environmental impacts of regular emission gases

Impacts of air emission from stacks of Ca Mau 2 power plant as well as the both CM1 and
CM2 power plants are assessed basing on the worst situation due to using maximum
ground concentration as forcast for above pollutants to compare with air quality standard.
This concentration is found at specific sites. The concentration at other places is lower.
When the plant uses DO fuel, the emission gases in this case are calculated in the worse
case with sulphur content of 0.5%. Diagram of pollutants dispersion: SOx, NOx and CO in
four selected options are showed in Appendix 2.

     Maximum ground average concentration of pollutants from particular stack and both
     stacks in the plant 2 as options 1 & 2 are summarized as follows:
-    SO2 concentration on the ground
     Maximum average daily ground concentration of SO2 from particular stacks as well as
     the both stacks in case of using DO (sulfur content of 0.5%wt) is higher than case of
     using natural gas, but it is still much lower than allowable ambient air concentration of
     TCVN 5937:1995. Maximum hourly and daily average ground concentration of NO2 is
     within 1.6 to 3.2 kilometers from foot of stacks towards Southeast and West-South West
     in case of using gas or South in case of using DO fuel.
-    NOx ground concentration
     Maximum average hourly and daily ground concentration of NOx from stacks in Ca Mau
     2 power plant using DO fuel is also higher 2.7 times than using natural gas. Maximum 1
     hour and 24 hours average ground concentrations of NOx from two stacks using DO fuel
     are 79.93μg/m3 and 18.96 μg/m3 respectively (far about 2km from stack toward the
     South or 3.6km toward the East – Northeast) are much lower than allowable standard of
     400μg/m3 for average 1 hour and 100 μg/m3 for average 24 hours.
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-   CO ground concentration
    Maximum average hourly ground concentration of CO from stacks of the CM2 power
    plant in both cases using natural gas and DO fuel is 6.67 – 7.27 μg/m3, at place far about
    1.6 - 2km from foot of stack toward the Southeast or the South. This concentration is
    much lower than ambient air environment standard (40,000 μg/m3).

-   Dust concentration on the ground
    Maximum 1 hour and 24 hours average ground concentration of dust in case of using
    DO as fuel (5.411μg/m3 and 1.28μg/m3 respectively) is 2 times higher than case of using
    natural gas (2.917μg/m3 and 1.041μg/m3 respectively) and are much lower than Vietnam
    standard (TCVN 5937:1995).

Thus, pollutants generate due to operation of Ca Mau 2 power plant are very smaller and
lower than ambient air environment standard.

    Maximum average ground concentrations of pollutants dispersed from four stacks of
    both plant 1&2 following options 3 & 4 are summarized as follows:

When Ca Mau 2 power plant comes into operation in March, 2008, Ca Mau 1 power plant
has been stabilized operation. So environmental impact from regular emission gases of Ca
Mau 2 power plant will be assessed in combining with air emission impact of Ca Mau 1
power plant. Result of air emission dispersion modeling from four stacks of both CM1 and
CM2 power plants is summarized as below:
-   In worst case, when the both plants are using DO with sulfur content 0.5 % wt, maximum
    average daily ground concentration of SO2 is 74.266μg/m3. This concentration is lower
    than ambient air environment standard of 300 μg/m3 (TCVN 5937:1995).
-   NOx ground concentration is highest when both plants using DO fuel. Maximum hourly
    and daily average ground concentrations are 153.856 and 39.59 μg/m3 respectively.
    Those concentrations are also lower than allowable limit of ambient air environmental
    standard.
-   CO ground concentrations in case of using natural gas as well as in case of using DO
    fuel are almost the same and are very small comparing with Vietnamese standard
    (TCVN 5937:1995).
-   When Ca Mau 1 and Ca Mau 2 power plants using DO as fuel, maximum daily average
    ground dust concentration is about 2.68μg/m3 that is very small comparing with allowable
    standard.

According to the result of environmental baseline survey at Ca Mau 2 power plant area on
December 2005, contents of pollutants are as follows:
    -
        SO2:        38 μg/m3
    -   NOx:        27 μg/m3
    -
        CO:      3500 μg/m3

Regular air emission dispersion from the operation of Ca Mau 2 power plant in both cases of
using 100% natural gas and 100% DO as fuel with maximum sulfur content of 0,5%wt
adding to existing environment concentration is still lower than allowable limit of ambient air
environmental standard (TCVN 5937:1995). So, air emission of Ca Mau 2 power plant in the
both case of using natural gas and DO as fuel will not cause significant impact on air
environment of the area.

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Due to CM2 power plant is gas turbine combined cycle power plant, emission temperature at
stack outlet is not high (97oC). Furthermore, Ca Mau power plant is built on agricultural area
and it is not obstructed by any building. So air emission from stack of 40m height will not
cause heat pollution for ambient air environment.

2. Impacts of dust and steam from cooling tower system.

Operation process of the cooling tower system follows the obligatory cooling principal. Cycle
water sprays down through tap that will be continuously knocked against net bar and wind
will be sucked from underneath to make very small water drops. These drops contact air
causing maximum increasing heat exchange surface. Process of wind inverse blowing from
underneath will take away considerable water and dust (containing water) to the
atmosphere, causing local increasing the dust concentration at the adjacent area of cooling
tower. Furthermore, the continuous operation process of cooling tower will cause
sedimentation on the surface of heat exchange system and net box. That will cause increase
dust content in water sweeping to the atmosphere. However, scale of dust dispersion only
limited in plant area and impact level is assessed as minor and long-term during the plant
operation.

3. Impacts of noise

In the operation phase of the power plant, the noise mainly generates from gas and steam
turbines, fans of cooling tower system and main pumps (supply water, condensed water,
cooling water.)

These equipment continuously operating and make noises during 24 hours in day. Similarly
with Ca Mau 1 power plant equipment, Ca Mau 2 power plant equipment are designed with
purpose to limit and reduce noise to ensure the allowable standards for workers and noise
standards for resident living around the plant, such as:
    In the plant area, noise from the normal operating of equipment and turbine will be
    limited under 85dB in distance of 1m and height of 1.5m above the surface of the noisy
    equipment. In case of incidents happening at exhausted pipe that has limited noise of
    100dB in the distance of under 1m from noise equipment (anti-noise coverage) and
    related pipeline. In general, noise generated from the plant operation will effect directly
    on labor force, cause tense, headache and may reduce working productivity. The noise
    impact on the labor force inside the plant is assessed as moderate during the plant
    operation.
    For outside of the plant area: installing the soundproof wall at the gas and steam turbine
    apartment as well as other equipment generating noise will limit much noise to outside.
    At the plant boundary, the project will obey noise standards for industrial plants built in
    the resident area (75dB in daytime and 70dB in nighttime and 50dB in mid-night to
    morning). Therefore, the noise impact level on the resident area surrounding the plant is
    assessed as insignificant.

4.2.2.2 Impact on water quality

The sources impact on water quality due to operation of Ca Mau 2 power plant as follows:
−  Cooling water intake for both CM1 and CM2 power plants
−  Cooling water discharge
−  Industrial wastewater discharge
−  Domestic wastewater discharge



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To set up discharge site and assess impact level of above affected sources, RDCPSE has
used the model of “Calculation of current regime and dispersion of wastewater and cooling
water” designed by Associate Professor Dr. Nguyen Tat Dac. This model was built basing on
theoretical basis of Japanese wastewater dispersion model 1975 using dispersion
calculation of cooling water for Japanese power plant as well as other plants in the world.
This model has used hydraulic field from SAL hydraulic model to calculate the water velocity
and water level. This model was also used by Netherlands company NEDECO to make the
Master plan of the Mekong delta and HASKONING company (Netherland) and used for
calculating current regime of waterway route from Ho Chi Minh City - Kien Luong – Ca Mau
and utilised to assess the environmental impacts for many projects such as: Phu My power
plant, O Mon power plant, projects in Thi Vai – Vung Tau, Saigon – Dong Nai and Mekong
delta. The basic calculation of this model is showed at the appendix 3.
Input data of current velocity, water level and using capacity to calculation for modeling is
taken from hydrographic measure during December 2000 to July 2001. The scale of
calculation basing on hydraulic model to calculate for the whole Ca Mau peninsula is limited
from Hau River inward and from Cai San to the sea. This model is used for planning projects
in Ca Mau peninsula and it was applied to calculate the variation of current regime, water
level, temperature and pollutant dispersion ability (ToC, BOD, DO, NH4+, NO2-, NO3-, total
N...) on the river system controlled by the tide at different using water conditions.
The continuous intake of cooling water (2m3/s) and continuous discharge (0.4m3/s) into Cai
Tau River also affect to the current variation and pollutant dispersion in treated industrial
wastewater into Cai Tau river. Moreover, Ca Mau 2 power plant comes into operation in
March-2008, the CM1 power plant are operating regularly and also discharge cooling water
and industrial wastewater into Cai Tau river. So when calculating the modeling, all
discharges and intakes of both plants (CM1 and CM2 power plants) are also considered to
assess combined impacts from their activities:
      1.   Cooling water intake is 2m3/s for CM1 & CM2 plants;
      2.   Cooling water discharge is 0.4m3/s of CM 2;
      3.   Cooling water discharge is 0.4m3/s of CM 1;
      4.   Industrial wastewater discharge is 0.008m3/s of both plants
On the other hand, the existing of Tac Thu dock and the closing of Tac Thu sluice in dry
season for preventing salinity intrusion are selected period for running model of current
variation and wastewater dispersion. Options of cooling water intake and wastewater
discharge for both CM1 and CM2 power plants are summarized in Table 4.8 and Figure 4.1
(vertical section).

            Table 4.8 OPTIONS FOR COOLING WATER INTAKE AND DISCHARGE
                          FOR CM1 AND CM2 POWER PLANTS
Opt          Discharge condition           Q (m3/s)Intake/dischar      Coordinate           Note
 .                                                     ge site
P.0    Current option: present of Tac Thu sluice, but without power plant for comparing
P.1    Intake cooling water for both       2      Cai Tau river    X=1022138.062 - Running in
       CM1 and CM2 power plants                   (VT0)            Y=397125.328        6 months of
       Discharging cooling water of       0.4     Cai Tau river    X=1022595.920 dry season
       the CM1 power plant                        (VT1)            Y=396887.920        (Nov.–Apr.)
       Discharging industrial           0.008 Cai Tau river        X=1022311.527 -The Tac Thu
       wastewater of CM1 & CM2                    (VT 2)           Y=397024.993        sluice is
                                                                                       closed to
       power plants
                                                                                       keep fresh
       Discharging cooling water of       0.4     Cai Tau          X=1021946.000
                                                                                       water.
       CM2 power plant                            confluence       Y=397733.000
                                                  (VT4)
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P2    Intake water for both CM1 and           2      Cai Tau river       X=1022138.062
      CM2 power plants                               (VT0)               Y=397125.328
      Discharging cooling water of           0.4     Cai Tau river       X=1022595.920
      the Ca Mau power plant 1                       (VT1)               Y=396887.920
      Discharging industrial               0.008     Cai Tau river       X=1022311.527
      wastewater of CM 1&CM2                         (site VT 2)         Y=397024.993
      Power plants
      Discharging cooling water of           0.4     Cai Tau river       X=1021964.009
      the Ca Mau 2 power plant                       (site VT 3)         Y=397256.066

Due to two power plants located at area influenced by tide of East Sea and West Sea, it’s
heavy rainfall in the rainy season but it seems to have no rain in the dry season. So surplus
water occurs in the rainy season and water lacking in the dry season. Therefore, in thermal
dispersion modeling of cooling water and pollutant dispersion modeling will only consider
and run for six dry months with the worst case of Tac Thu sluice closing to keep water.

It’s noted that all sites of cooling water intake (VT0), cooling water discharge of the CM1
power plant (VT1), discharging industrial wastewater of the CM1 and CM2 power plants
(VT2) and discharging cooling water of CM2 power plant (VT3 or VT4) are all on the left
bank of Cai Tau river (see from Cai Tau confluence) within 1500m in length (from cooling
water discharge site of CM1 power plant (VT1) to Cai Tau confluence (VT4). The existing of
the water intake and discharge area can be summarized as follows:

     The Cai Tau river’s width is about 60m, in the future it will be enlarged for a port of 160m.
     The river water is saline intruded in the dry season, the values of pH, salinity, and
     turbidity vary clearly depending season. Basing on analysis result of water quality in
     December, 2005 and comparing to analytical data of 2002, the water section of Cai Tau
     river at the power plant has signal of organic pollution due to the wastewater of Ngoc
     Sinh seafood processing plant and Cai Tau residential area.

     Riverbed topography of Cai Tau river is rather flat, sediment is fine silt, black-brown
     mixing with decayed leaves and roots. Before dredging, depth of this river is about 2.5-
     3m and after dredging to expand port area, the depth of this section will be 4m.

     At present, left bank of Cai Tau River section is no vegetation because of clearance and
     consolidation process at two power plants. In the future, this river bank will be concreted
     for anti-erosion;

     Right bank of the Cai Tau river section is the Cai Tau residence center with a lot of
     boats. All of domestic waste water discharge directly into Cai tau river causing bad smell;

     300m far from Cai Tau confluence towards Ong Doc river, Tac Thu ship dock has
     already finished and being testing process.




CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                      70




                          W est sea direction
                          T ransect   D istance
                           nam e        (km )
                           3335
                                         0.7
                            3336
                                         0.7
           S ite 1          3337
                            1725
                                         0.1
   Ca                       1726
                                                                              NOTE
                                         0.1
   M au                     1727
                                         0.1                                   W ater intake site
   pow er                   1728
           S ite 2
   plant 1                  3341                                         W astew ater discharge site
                                         0.1
   area                     3342                                   3343 Transect nam e infront of w ater
                                         0.1                       3365 Transect nam e rearw ards of w ater taking site
           S ite 0          3343                                    0.25 D istance betw een tw o transects (km )
                            3365
            Intake 2m 3
                                        0.25
                            3366
                                        0.25
           S ite 3          3367
                            3368
                                        0.25                   To Thoi B inh
                            3369
                                        0.25
                            3370
                            1729          Cai Tau Confluence
                                         0.3
                            1730        Tac Thu Sluice
                            3344
                                         0.4
                            3345
                                         0.4
           S ite 4          3346
                            3347
                                         0.6
                            3348
                                         0.6
                            3349
                            1731
                                         0.7
                            1732
                                         0.7
                            1733
                                         0.7
                            1734
                            1735
                                        0.35                   Ca M au city
                            1736
                                        0.35



     Fig 4.1 DIAGRAME OF COOLING WATER INTAKE SITE, DISCHARGE SITES IN
                        OPTIONS AND TRANSECT SITES

Note:

To distinguish current regime or concentration before and after discharged site as well as
intake site, in calculation schema prior and behind section will be named. At Cai Tau
confluence or Tac Thu confluence to Ca Mau will also such section to distinguish dividing of
current.

In data tables, these points are marked by red circle ( ), section name is recorded by
ordinal number as Figure 4.1. Tac Thu sluice is symbolized as blue cross ( ). Location of
intake and discharge sites is symbolized as follows:


CPMB– RDCPSE-Final report                                                                                     June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)          71


−   VT0: Cooling water intake site for both CM1 & CM2 power plants
-   VT 1: Cooling water discharge site of CM1 power plant
-   VT 2: Industrial discharge site of both CM1 & CM2 power plants
-   VT 3: Cooling water discharge site of CM2 power plant at Fertilizer port - option 2
-   VT4: Cooling water discharge site of CM2 power plant at Cai Tau confluence - option 1

Modeling Results
1. Variation of water current of Cai Tau river and Ong Doc river due to cooling water
   intake and wastewater discharge

The project area is controlled by two tidal regimes, semi-diurnal tidal regime from East Sea
with amplitude of 3m from Ganh Hao, My Thanh rivers, and diurnal tidal regime of West sea
with amplitude of 1-1.5m from Ong Doc and Cai Lon river. Current direction often changes
one or two times within 30 minutes/time during a day. When tidal turning, current is almost
zero (stand current). This characteristic will make discharged effluents not yet diluted then
turned oppositely.

    In case of Tac Thu sluice is opened

When existing both CM and CM2 power plants at this area, the regular intake of cooling
water with flow rate of 2m3/s from Cai Tau river and discharge cooling water as well as
treated industrial wastewater into Cai Tau river will change the current on this river system.
When both power plants come into operation, average flow rate of Cai Tau – Ong Doc river
as opening Tac Thu sluice, is given in Table 4.9 and Figure 4.2.

    Table 4.9   AVERAGE FLOW OF CAI TAU – ONG DOC RIVER (m3/s) IN THE DRY
             SEASON WHEN THE POWER PLANTS COME INTO OPERATION
                        (in case of opening Tac Thu sluice)

    Transect’s           Qaver. P0             Qaver. P1             Qaver. P2              Position
      name
      3335                   21                  23.2                  24.5
      3336                   21                  23.2                  24.5
      3337                   21                  23.2                  24.5                     VT1
      1725                   21                  23.6                  24.5
      1726                   21                  23.6                  24.5
      1727                   21                  23.6                  24.5
      1728                   21                  23.6                  24.5                     VT2
      3341                   21                  23.6                  24.5
      3342                   21                  23.6                  24.5
      3343                   21                  23.6                  24.5           Taking 2m3/s VT0
      3365                   21                  21.6                  22.5
      3366                   21                  21.6                  22.5
      3367                   21                  21.6                  22.5                     VT3
      3368                   21                   22                   22.5
      3369                   21                   22                   22.5
      3370                   21                   22                   22.5               Cai Tau
      1729                  13.2                 14.4                  14.7            confluence VT4
      1730                  13.2                 14.4                  14.7            Tac Thu sluice
      3344                  13.2                 14.4                  14.7
      3345                  13.2                 14.4                  14.7
      3346                  13.2                 14.4                  14.7
      3347                  13.2                 14.4                  14.7

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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                                                           72


                    3348                          13.2                          14.4                             15.5
                    3349                          13.2                          14.4                             15.5
                    1731                          13.2                          14.4                             15.5
                    1732                          13.2                          14.4                             15.5
                    1733                          13.2                          14.4                             15.5
                    1734                          13.2                          14.4                             15.5                  T-junction to Ca
                    1735                          25.7                          26.2                             27.1                      Mau city
                    1736                          25.7                          26.2                             27.1
                    1737                          25.7                          26.2                             27.1
                    3350                          25.7                          26.2                             27.1
                    3351                          25.7                          26.2                             27.1
                    3352                          25.7                          26.2                             27.1


               28

               26

               24

                                                                 Taking 2m3/s
               22
    Q (m3/s)




               20

               18
                                                                                       Tac Thu river section
                                  Cai Tau river section
               16

               14

               12
                                                                                                                        1733

                                                                                                                                1735

                                                                                                                                       1737

                                                                                                                                              3351
                                                                                                                 1731
                                                                 3367

                                                                         3369

                                                                                1729

                                                                                            3344

                                                                                                   3346

                                                                                                          3348
                                                  3342

                                                          3365
                    3335

                           3337

                                    1726

                                           1728




                                                                        Transection's name
                                             P0                                        P1                                      P2



               Figure 4.2 AVERAGE FLOW ALONG CAI TAU – ONG DOC RIVER IN CASE OF
               WITHOUT AND WITH TWO POWER PLANTS – AS OPENING TAC THU SLUICE

Calculation results in the dry season (from November to April) in Table 4.9 and Figure 4.2,
in the case of Tac Thu opening show that:
-         Regular cooling water intake of 2m3/s for both CM1 and CM2 power plants will increase
          the water volume from Cai Tau river toward Ong Doc river which makes increasing flow.
          For example, at cooling water intake site VT0, average flow increases from 0.6 to1.5
          m3/s and at cooling water discharge (VT1) and industrial wastewater discharge (VT2) of
          the CM1 and CM2 power plants increases from 2.2 to 3.5m3/s.
-         Current velocity of the Cai Tau river section from cooling water discharge site of CM1
          power plant (VT1) to Cai Tau confluence is higher than the current velocity from Cai Tau
          confluence to Ong Doc – Tac Thu confluence.
-         The tendency of average flow is from Ca Mau flowing to Ong Doc river and from Cai Tau
          confluence flowing to the sea via Ong Doc river.



CPMB– RDCPSE-Final report                                                                                                                            June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)       73


    In case of Tac Thu sluice is closed

Average flow of Cai Tau – Ong Doc river is given in Table 4.10 and Figure 4.3.

 Table 4.10 AVERAGE FLOW RATE OF CAI TAU – ONG DOC RIVER (m3/s) IN THE DRY
              SEASON WHEN POWER PLANTS COME INTO OPERATION
                       (In case of Tac Thu sluice is closed)

  Transect’s name           Qaver.P0        Qaver.P1           Qaver.P2               Position

         3335                 23.3            20.6               20.2
         3336                 23.3            20.6               20.2
         3337                 23.3            20.6               20.2                   VT1
         1725                 23.3             21                20.6
         1726                 23.3             21                20.6
         1727                 23.3             21                20.6
         1728                 23.3             21                20.6                   VT2
         3341                 23.3             21                20.6
         3342                 23.3             21                20.6
         3343                 23.3             21                20.6           taking 2m3/s VT0
         3365                 23.3             19                18.6
         3366                 23.3             19                18.6
         3367                 23.3             19                18.6                   VT3
         3368                 23.3             19                 19
         3369                 23.3             19                 19
         3370                 23.3             19                 19                Cai Tau
         1729                  0               0                   0             confluence VT4
         1730                  0                0                  0             Tac Thu Sluice
         3344                  0                0                  0
         3345                  0                0                  0
         3346                  0                0                  0
         3347                  0                0                  0
         3348                  0                0                  0
         3349                  0                0                  0
         1731                  0                0                  0
         1732                  0                0                  0
         1733                  0                0                  0
         1734                  0                0                  0            Confluence to Ca
         1735                 20.6            19.9               19.8               Mau city
         1736                 20.6            19.9               19.8
         1737                 20.6            19.9               19.8
         3350                 20.6            19.9               19.8
         3351                 20.6            19.9               19.8
         3352                 20.6            19.9               19.8




CPMB– RDCPSE-Final report                                                                        June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                                                74



                 24

                                                                                          (Q>0 from Cai Tau-Tac Thu-Ong Doc river
                 22
                                                                                                         to the sea)

                 20
      Q (m3/s)




                 18
                                                         Taking 2m3/s

                 16                                                                    Tac Thu river section
                                Cai Tau river section

                 14


                 12
                      3335

                             3337

                                    1726

                                           1728

                                                  3342

                                                         3365

                                                                  3367

                                                                         3369

                                                                                1729

                                                                                        3344

                                                                                               3346

                                                                                                      3348

                                                                                                             1731

                                                                                                                    1733

                                                                                                                            1735

                                                                                                                                   1737

                                                                                                                                           3351
                                                                Transect's name along the river

                                            P0                                     P1                                      P2


    Fig.4.3 AVERAGE FLOW RATE ALONG CAI TAU – ONG DOC RIVER WITHOUT AND
              WITH TWO POWER PLANTS (in case of closing Tac Thu sluice)
From above results in case of closing Tac Thu sluice, it can be drawn as follows:
−    When Tac Thu sluice is closed, maximum down flow and back flow current on the Cai
     Tau river much decrease in comparing as sluice opening. Immediate current in Ong Doc
     river section from Cai Tau confluence to Tac Thu confluence is very small and average
     current is mostly zero.
−    At the cooling water intake site (VT0), average flow reduces from 2.3 to 2.7m3/s. At the
     cooling water discharge site of CM1 power plant (VT1) and the CM2 power plant (VT3),
     the average flow decreases from 4.3 – 4.7m3/s.
−    The continuous cooling water intake of 2m3/s for both CM1 and CM2 power plants will
     make the water level reduced from 1 to 6cm.
−    Although the current on Cai Tau and Ong Doc rivers decreases in comparing with case
     of opening sluice but it is still higher than flow on the downstream river from Tac Thu
     sluice.

2. Heat pollution on Cai Tau river due to the cooling water discharge

After the heat exchanging process at cooling tower, the used cooling water (CW) will be
regularly discharged into Cai Tau river with flow rate of 0.4m3/s (1,440m3/h) with the
discharged temperature in normal operation condition at 35oC. In case of gas tail incident
(rarely happen), cooling water discharge temperature is highest of 40oC. Because the
cooling water is not taken place to technological process, but it only used for heat exchange,
so it is classified as a clean wastewater (not polluted by pollutants and plant’s chemical).

In practical, cooling water at the discharge end in CM2 power plant will be routed via
discharged pipeline with 1,038m length to Cai Tau river, in which 250m is closed pipeline
and 788m open pipeline. Therefore the temperature at the outlet to Cai Tau river will reduce
considerably and completely meet Vietnamese Standard TCVN 5945:1995. However, due to
high quantity of regular cooling water discharged into the river that is controlled by both East
and West sea tide, so heat impact on environment has to be also assessed in detail.

CPMB– RDCPSE-Final report                                                                                                                 June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)           75


In order to assess the heat impact of cooling water on the Cai Tau’s aquatic environment
and its vicinity, RDCPSE has used cooling water dispersion model running for two following
options in normal case (35oC) and in emergency one (40oC).
        -     Option 1 (P1): cooling water discharged to Cai Tau confluence (VT4)
        -     Option 2 (P2): cooling water discharged to Port area (VT3)

Input data of Modeling

During calculating, it is necessary to consider all of the accumulative effects between CM1 &
CM2 power plants as mentioned in Table 4.8 including intake and discharged cooling water
effluents and Tac Thu sluice are shut down in the dry season. Input data of cooling water
dispersion modeling is listed as follows:
     - Average temperature of river at the discharge site is 28oC
     - Cooling water temperature at outlet is 35oC in normal operation
     - Cooling water temperature at outlet is 40oC in tail gas incident
     - Discharge flow rate of 0.4m3/s
     - Average atmosphere temperature in Ca Mau area is 30oC
     - Average wind speed in Ca Mau area is 1.5m/s
     - Relative humidity in Ca Mau area is 80%
     - Temperature’s diffusion coefficient is 30m2/s
     −  Heat exchange coefficient depending on Hydro meteorological condition and referred
        from Wada chart: Qo=530cal/m2/s and Q1=17cal/m2/s.oC [19]
     - Calories at heat source to the river are calculated by formula: W=ρ.Cρ.q.Ts with q
        (discharged flow rate), ρ (water density), Ts (discharged temperature), Cρ (heat
        capacity of water) [Appendix 3].
     - Discharge mode: horizontal discharge to the surface layer through discharged outlet
        far about 15m from riverbank.

Modeling results

    In case of discharged cooling water temperature of 35oC

The detail result of average and maximum temperature increase along Cai Tau - Ong Doc
river in two discharged options with discharged temperature of 35oC is shown in Table 4.11
and Figures 4.4 & 4.5.
         Table 4.11 AVERAGE AND MAXIMUM TEMPERATURE INCREASE
  ALONG CAI TAU - ONG DOC RIVER BY 2 DISCHARGED OPTIONS IN 6 MONTHS OF
              DRY SEASON - DISCHARGED TEMPERATURE OF 35oC

   Transect        TmaxP1        TmaxP2        Taver,P1        Taver,P2     Distance (km)            Site
    name
     3335           2.96          3.03           0.65           0.66               0
     3336           3.14          3.17           0.87           0.86             0.7
     3337           3.50          3.50           1.09           1.07             1.4                 VT1
     1725           3.50          3.50           1.11           1.10             1.4
     1726           3.44          3.44           1.04           1.04              1.5
     1727           3.37          3.37           0.98           0.98              1.6
     1728           3.31          3.36           0.90           0.92              1.7                VT2
     3341           3.31          3.36           0.91           0.92              1.7
     3342           3.28          3.34           0.89           0.92              1.8
     3343           3.28          3.34           0.87           0.92              1.9           Take 2m3/s VT0
     3365           3.28          3.34           0.87           0.91              1.9
     3366           3.18          3.42           0.87           0.91             2.15
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     3367                   3.16                   3.50                    0.88                      0.98                      2.40                      VT3
     3368                   3.16                   3.50                    0.88                      1.05                      2.40
     3369                   3.33                   3.29                    1.01                      1.05                      2.65
     3370                   3.50                   3.26                    1.10                      0.46                       2.9                 Cai Tau
     1729                   3.50                   3.26                    1.10                      0.44                       2.9              confluence VT4
     1730                   0.01                     0                       0                         0                        3.2              Tac Thu sluice
     3344                   0.07                   0.08                    0.05                      0.06                       3.2
     3345                   0.07                   0.08                    0.05                      0.06                       3.6
     3346                   0.07                   0.08                    0.05                      0.06                        4
     3347                   0.07                   0.08                    0.05                      0.06                        4
     3348                   0.08                   0.09                    0.06                      0.06                       4.6
     3349                   0.14                   0.13                    0.06                      0.06                       5.2
     1731                   0.14                   0.13                    0.06                      0.06                       5.2
     1732                   0.27                   0.26                    0.06                      0.06                       5.9
     1733                   0.42                   0.41                    0.07                      0.07                       6.3
     1734                   0.66                   0.65                    0.07                      0.07                        7                Confluence to
     1735                   0.66                   0.65                    0.07                      0.07                        7                  Ca Mau
     1736                   0.64                   0.63                    0.07                      0.07                        -
     1737                   0.64                   0.63                    0.07                      0.07                        -
     3350                   0.64                   0.63                    0.07                      0.07                        -
     3351                   0.62                   0.61                    0.07                      0.07                        -
Note: Distance (km) is calculated from transect 3335 to Tac Thu confluence to Ca Mau. At discharge site will
have closed prior and behind transects so distance at this site is considered as zero. When current is conversed
(v=0), temperature reaches maximum value.


                        Fig 4.4 HIGHEST TEMPERATURE INCREASE BY DISCHARGED
                      OPTION DURING 6 DRY MONTHS (DISCHARGED TEMPERATURE OF
                                                35oC)
                CW discharge site-CM1                     CW discharged site CM2(P2)                                   CW discharged site CM2 (P1)
          4

         3.5

          3

         2.5
   ToC




          2

         1.5

          1

         0.5

          0
               0Km




                                                                                                                 2.9
                                                                                                                       3.2
                                                                                                                             3.2
                                                                                                                                   3.6




                                                                                                                                                                   5.9
                                                                                                           2.9




                                                                                                                                         4
                                                                                                                                             4
                                                                                                                                                 4.6
                                                                                                                                                       5.2
                                                                                                                                                             5.2


                                                                                                                                                                         6.3
                                                                                                                                                                               7
                     0.7
                           1.4
                                 1.4
                                       1.5
                                             1.6
                                                   1.7
                                                         1.7
                                                               1.8
                                                                     1.9
                                                                           1.9


                                                                                        2.4
                                                                                              2.4
                                                                                 2.15




                                                                                                    2.65




                                                                                         Distance (Km)


                                                                                        Tmax P1                   Tmax P3




CPMB– RDCPSE-Final report                                                                                                                                June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                              77



                     Fig. 4.5 AVERAGE TEMPERATURE INCREASE BY DISCHARGED OPTION DURING 6
                                  DRY MONTHS (DISCHARGED TEMPERATURE OF 35oC)
                CW discharge site-CM1           CW discharge site- CM2 (P2)         CW discharge site- CM2 (P1)
         1.2


          1


         0.8
   ToC




         0.6


         0.4


         0.2


          0
               0Km


                        1.4


                              1.5


                                        1.7


                                              1.8


                                                     1.9


                                                             2.4


                                                                      2.65


                                                                              2.9


                                                                                      3.2


                                                                                               4


                                                                                                       4.6


                                                                                                                  5.2


                                                                                                                         6.3
                                                             Distance (Km )

                                                              TbqP1           TbqP3



The above results show that:
    Regular cooling water discharge of the two power plants into Cai Tau river will cause
    light increase of water environment’s temperature on Cai Tau river section from cooling
    water discharge site of CM1 power plant (VT1) to Cai Tau confluence (VT4) in the
    distance of about 1.5km. This will cause insignificant impact on water quality of Cai Tau
    and Ong Doc rivers.

    At the discharge site, the average temperature’s increases of both discharge option 1
    and 2 are similar at 1.1oC. At cooling water intake site, the temperature difference
    decreases about 0.87 - 0.91oC. From downstream of Tac Thu sluice following to Ong
    Doc river, temperature difference according to two options is only 0.05oC – 0.07oC.
    At the stand tide (v=0), the maximum temperature increase at the discharge sites vary in
    the range of 3.26-3.5oC. At the cooling water intake site (VT0), far from cooling water
    discharge of CM1 (VT1) and CM2 (VT3) is about 500m, maximum temperature increase
    is about 3.28oC for option 1 and 3.34oC for option 2. Because Cai Tau river is controlled
    by west sea and east sea tide, so in a day, there are at least one tidal change (diurnal
    tide) and maximum 2 tidal changes (semi-diurnal tide), each tidal changing time lasts
    only in 30 minutes. Thus, the time of high temperature lasts in the range of 30 minute to
    1 hour/day. Furthermore, highest temperature increase at stand tide is still within in
    seasonal variation so it will cause insignificant impact on cooling water intake for two
    plants and water supply for aquaculture along the Cai Tau river.
    Comparing the two options, temperature increase between them is similar.




CPMB– RDCPSE-Final report                                                                                               June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)            78


    In case of discharged cooling water temperature of 40oC
In case of gas tail incident, calculation result of average and maximum temperature increase
along Cai Tau - Ong Doc river in two cooling water discharge options with discharged
temperature of 40oC in six dry months are summarized in Table 4.12 and Figure 4.6 &4.7.
              Table 4.12 AVERAGE AND MAXIMUM TEMPERATURE INCREASE
                            ALONG CAI TAU-ONG DOC RIVER

  Section name     Taver,P1      Taver,P2       TmaxP1         TmaxP2        Distance (km)            Site
      3335          1.64          1.42           7.61            7.8               0
      3336          2.13          1.86           8.08           8.16              0.7
      3337          2.66          2.34             9              9               1.4                 VT1
     1725           2.73          2.42             9              9               1.4
     1726           2.56          2.29           8.85           8.86             1.5
     1727           2.38          2.16           8.66           8.59             1.6
     1728           2.21          2.03           8.52           8.47             1.7                  VT2
     3341           2.21          2.03            8.5           8.46              1.7
     3342           2.17          2.02           8.44           8.41             1.8
     3343           2.13          2.01           8.43           8.46             1.9            intake 2m3/s VT0
     3365           2.13          2.01           8.43           8.46             1.9
     3366           2.13          2.16           8.15            8.7             2.15
     3367           2.13          2.32           8.11             9              2.40                 VT3
     3368           2.14          2.35           8.11             9              2.40
     3369           2.46          1.57           8.55           8.45             2.65
     3370           2.67          1.06             9            8.37              2.9              Cai Tau
     1729           2.66          1.03             9            8.36              2.9           confluence VT4
     1730           0.01            0            0.02           0.01              3.2            Tac Thu sluice
     3344           0.13          0.13           0.18           0.18             3.2
     3345           0.13          0.13           0.18           0.18             3.6
     3346           0.13          0.13           0.19           0.19               4
     3347           0.13          0.13           0.19           0.19               4
     3348           0.14          0.14           0.22           0.21             4.6
     3349           0.15          0.14           0.33           0.32             5.2
     1731           0.15          0.14           0.33           0.32             5.2
     1732           0.16          0.15           0.66           0.64             5.9
     1733           0.17          0.15           1.04           1.02             6.3
     1734           0.17          0.16           1.62           1.60               7            Confluence to Ca
     1735           0.18          0.16           1.62            1.6               7                  Mau
     1736           0.18          0.16           1.59           1.56               -
     1737           0.18          0.16           1.58           1.54               -
     3350           0.18          0.16           1.58           1.54               -
     3351           0.18          0.17           1.53            1.5               -




CPMB– RDCPSE-Final report                                                                            June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)                                                                     79



                               3
 temperature increase ToC
                              2.5

                               2

                              1.5

                               1

                              0.5
                                                  Cai Tau river                                                      Tac Thu - Song Doc river

                               0




                                    3352
                                    1733
                                    1734
                                    1735
                                    1736
                                    1737
                                    3350
                                    3351
                                    3337

                                    1726
                                    1727
                                    1728

                                    3342
                                    3343
                                    3365
                                    3366
                                    3367
                                    3368
                                    3369
                                    3370
                                    1729
                                    1730
                                    3344
                                    3345
                                    3346
                                    3347
                                    3348
                                    3349
                                    1731
                                    1732
                                    3335
                                    3336

                                    1725




                                    3341




                                                                                           Location along river
                                                                                                    P2              P1

Fig. 4.6 AVERAGE TEMPERATURE INCREASE ALONG THE RIVER IN TWO OPTIONS
           IN SIX DRY MONTHS – DISCHARGED TEMPERATURE OF 40oC


                              10
                                9
   Temperature increase ToC




                                8
                                7
                                6
                                5                        Cai Tau River
                                                                                                                      Ong Doc River
                                4
                                3
                                2
                                1
                                0
                                    3335

                                           3337

                                                      1726

                                                              1728

                                                                      3342

                                                                             3365

                                                                                    3367

                                                                                             3369

                                                                                                     1729

                                                                                                            3344

                                                                                                                   3346

                                                                                                                          3348

                                                                                                                                  1731

                                                                                                                                         1733

                                                                                                                                                1735

                                                                                                                                                       1737

                                                                                                                                                               3351



                                                                                           Location along river
                                              P2                     P1

Fig. 4.7                               MAXIMUM TEMPERATURE INCREASE ALONG THE RIVER IN TWO OPTIONS
                                        IN SIX DRY MONTHS – DISCHARGED TEMPERATURE OF 40oC
Above results show that:
                    In case of tail gas incident, cooling water discharge of CM1 & CM2 power plants to Cai
                    Tau river will increase significantly temperature of water environment on Cai Tau river
                    section from cooling water discharged point of CM1 power plant to Cai Tau confluence
                    (1.5km). However, cooling water temperature at outlet still meets Vietnamese
                    environmental standard of ≤40oC.
                    At discharge site, average temperature increases about 2.6oC in option 1 (VT4) and
                    2.3oC in option 2 (VT3). At cooling water intake, temperature difference is about 2.1oC
                    following option 1 and 2.0oC in option 2. From downstream of Tac Thu sluice via Ong
                    Doc river, temperature increase of two discharged options are only about 0.13-0.19oC.


CPMB– RDCPSE-Final report                                                                                                                                     June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)       80


    At the stand tide (v=0), maximum temperature increase are rather highly (8-9oC) due to
    discharge water is almost no diluted. At this time, highest temperature increase at
    cooling water intake is about 8.4oC that cause directly impact on cooling water intake for
    2 plants. However, in case of tail gas incident occured, the plant only operates at this
    regime within very short period. Furthermore, period for high temperature increase lasts
    no longer only about 30 minutes to 1 hour per day.

3. Impact of industrial wastewater
Industrial wastewater created during the the CM2 power plant’s operation, as well as the
CM1 power plant, includes:

−   Water from heat recovery steam generator: continuous discharge with regular average
    flow is about 4.6m3/hour at 100oC. Blow down water from the heat recovery steam
    generator is demineralizing water containing following components:
    + Phosphate:              6 mg/l
    + Ammoniac:               5 mg/l
    + Hydrazine:              2 mg/l
    + EC:                     3 - 5 μS
    The released water from blow down boiler with flow rate of 4.6m3/h is routed to cooling
    water tower to mixed with cooling water (1200m3/h) and then discharged to Cai Tau river.
    Basing on calculation, concentration of ion phosphate in boiler blow down is < 3mg/l and
    concentration of ion phosphate in cooling water discharge after mixing is < 0.012mg/l.
    According to the Industrial wastewater standard as discharge to the river that used for
    aqua-product protection purpose (TCVN 6984:2001), allowable limit for total phosphor
    content is 5mg/l. Thus, concentration of ion phosphate in cooling water discharged to Cai
    Tau river is very small and it will not cause any impacts on water quality of Cai Tau river.
−   Other wastewaters: including regular and irregular industrial wastewater. Flow rate of
    these effluents are summarized in Table 4.13.

     Table 4.13      INDUSTRIAL WASTEWATER TYPES OF THE CM2 POWER PLANT

                          Sources                                   Discharged flow rate (m3/h)
                                                                      Normal          Maximum
Regular wastewater
− Wastewater from RO of demineralization system                           10                   10
− Condensing water from gas supplying unit                               0.01                  001
− Wastewater from area of generator of GT                                  0                    2
− Wastewater from area of generator of ST                                  0                   72
− Wastewater from boiler                                                   0                    2
− Wastewater from transformer station                                      0                   36
− Wastewater from DO storage tanker                                        0                   10
− Wastewater from gas compressor                                         0.1                   0.1
− Wastewater from septic tank                                            1.7                    3
Total                                                                   11.81                135.11
                                                                   (# 0.0033 m3/s)       (# 0.0375m3/s)

The plant’s operation also generates an irregular wastewater (3-5 years/time) mainly from
de-mineralizing water system, wastewater from the heat recovery boiler, transformer area,
generator and diesel tank area. Estimated irregular wastewater is about 374m3/h. Other
regular and irregular industrial wastewaters containing a large quantity of suspended solid,
lubricant oil, and low pH will be routed to share treatment system located in CM1 Power
plant. Oily wastewater will be separated oil; others will be leaded to preliminary
sedimentation tank. Pre-treated wastewater will be directed into common tank and treated
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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)               81


(neutralizing, separating, etc.). Treated wastewater met Vietnamese Standard TCVN
6984:2001 will be discharged together with industrial wastewater of CM1 power plant to Cai
Tau river with discharged flow rate of 0.008m3/s at VT2 (coordinate X= 102231.527;
Y= 397024.993).
To evaluate effluence of industrial wastewater discharge of both CM1 & CM2 power plants
by organic pollution dispersion modeling on river/canal system during 6 months of the dry
season and in case of closing TacThu sluice, input data include:

−    Cai Tau river water is considered as rather clean with BOD of about 5mg/l;
−    Industrial wastewater after treatment met Vietnamese standard is considered as light
     pollution with discharged BOD of about 15mg/l;
−    Discharged wastewater flow rate of 0.008m3/s;
−    Discharge mode: horizontal discharge to the drainage closing to riverbank.

According to modeling results, average and maximum BOD content along Cai Tau –
Ong Doc river following location and transect is summarized in Table 4.14.
    Table 4.14     THE AVERAGE BOD (mg/l) ALONG CAI TAU – ONG DOC RIVER WHEN
                  BOTH POWER PLANTS DISCHARGE INTO CAI TAU RIVER
     Transect’s   BOD (baseline)     Average BOD          BOD max          Distance (km)             Site
       name          (mg/l)             (mg/l)             (mg/l)
       3335             5                5.07               5.74                 0
       3336             5                5.07               6.19                0.7
       3337             5                5.06               6.95                1.4                  VT1
       1725             5                5.07               7.04                1.4
       1726             5                5.15               9.30                1.5
       1727             5                5.23              14.73                1.6
       1728             5                5.30                15                 1.7                  VT2
       3341             5                5.30                15                 1.7
       3342             5                5.22              12.89                1.8
       3343             5                5.15               9.48                1.9         intake 2m3/s VT0
       3365             5                5.13               9.48                1.9
       3366             5                5.09              7.54                2.15
       3367             5                5.05               6.60               2.40                  VT3
       3368             5                5.04               6.35               2.40
       3369             5                5.04               5.86               2.65
       3370             5                5.03               5.77                2.9                Cai Tau
       1729             5                5.03               5.77                2.9             confluence VT4
       1730             5                  5                5.01                3.2             Tac Thu sluice
       3344             5                  5                5.01                3.2
       3345             5                  5                5.01                3.6
       3346             5                 5                 5.01                 4
       3347             5                 5                 5.01                 4
       3348             5                  5                5.01                4.6
       3349             5                  5                5.01                5.2
       1731             5                  5                5.01                5.2
       1732             5                  5                5.03                5.9
       1733             5                5.01               5.04                6.3
       1734             5                5.01               5.06                 7          Confluence to Ca
       1735             5                5.01               5.06                 7                Mau
       1736             5                5.01               5.06                 -
       1737             5                5.01               5.06                 -
       3350             5                5.01               5.06                 -
       3351             5                5.01               5.06                 -



CPMB– RDCPSE-Final report                                                                            June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      82


The dispersion modeling result of wastewater shows that, the average BOD at discharge site
(VT2) of two power plants only differs with baseline BOD of river of 0.3mg/l. The maximum
BOD content at discharge site is 15mg/l due to stand tide (v=0) it is not diluted. From Cai
Tau confluence down to Ong Doc river, BOD content is approximate baseline BOD of river is
about 5 mg/l. At water intake site, average BOD (5.15mg/l) increases insignificantly in
comparison with baseline BOD of Cai Tau river of 5 mg/l. Generally, the discharge treated
industrial wastewater of CM1 and CM2 power plants will cause insignificant on the water
quality of Cai Tau - Ong Doc river due to very small discharged volume.

4. Domestic wastewater
During the operation phase, number of the working staff at the Ca Mau 2 power plant is
about 150 persons. According to the discharge criteria from Vietnam Institute of Hygiene
Public health, the daily domestic wastewater volume is about 25m3. Domestic wastewater
will be treated in septic tank system and then routed to share treatment system of both
plants before discharging to Cai Tau river. Due to very small amount of wastewater so it is
almost no impact on water quality of Cai Tau river.

5. Run-off water
The run-off water from different areas will be also collected in floor water drainage system.
Run off water through oil tank area, outdoor transformer, equipment washing water, rainy
water drainage in initial rain (about 5 minutes to heavy rain) can be oily. That will be treated
at oily separation system and then routed to common treatment tank of the plant. In case
heavy rain, run off water is supposed clean and discharge into Cai Tau river. Rain water
discharge system in the plant is devided into many areas. Generally, runoff water will not
cause any affect to surface water quality.

4.2.2.3 Impacts on soil quality
The operation of the Ca Mau 2 power plant will impact to soil quality and sediment due to oil
spill or oil/chemical leak and other solidwaste.

1. Effects due to DO and chemical storage in the plant
For the productive demand, the plant has to store a big quantity of chemicals for operation,
and maintainance for 12 months.
Similar to CM1 ower plant 1, CM2 power plant 2 will use some normal inorganic substances
belonging to list of non-toxic or less toxic chemicals. Almost subtances (H2SO4, HCl, NaOH,
NaCl, Na2CO3, Na2SO3, Al2(SO4)3, FeSO4, …) are available in Vietnam and transported from
Ho Chi Minh City. At the plant, acid H2SO4 is stored with volume of 50m3 and other
chemicals is about 5 m3. The regular use of strong acid or alkaline as well as a big quatity of
chemicals in the plant’s area might cause spillage or leakage due to mistake or fault of the
workers. For these spillages, unless managed or suitably collected, they will pollute the
groundwater and the run-off water. Although the plant surface has been cemented, chemical
tanks in the area wilth embankment and anti-absorbent ground, but the soil environment
might be polluted by strong alkaline or acid leakage.
In case of the natural gas supplying is interrupted, the plant will have to use alternative DO
fuel. Diesel oil is stored in two tanks with volume of 5,000m3/tank. These are specific tanks
(double hulls) located on the concrete foundation and having bunded around, that can
contain 110% tank volume. Run-off water or leakage oil in the bund will be directed to oil
treatment system. Therefore, the spillage effect in the plant is considered as minor level. It is
necessary to minimise the oil spilll risk while unloading from ship to the plant’s tanks,
because the plant is located closed to T21 Canal, connecting to Cai Tau Confluence, so the
environmental risk is rather high.
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Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      83


2. Effect of solid waste

The CM2 power plant operation will generate a quantity of solid waste from some following
sources:
−  Industrial waste: including packing, oily rag, and little oil, chemical from normal activities
   and maintenance of the plant. The estimated quantity of industrial is about 0.5 –
   1tone/day;
−  Sludge from the wastewater treatment: including residual sludge from the wastewater
   treatment, as well as from the cooling tower;
−  Residue oily waste: generated from the oily separation system;
−  Domestic waste: in operation phase, about 150 employees will work in the Ca Mau
   Power plant 2. Estimated domestic waste is about 0.85kg/person/day and food-waste of
   0.58kg/person/day. Therefore, the waste quantity of the power plant is about 200 kg/day.
Unless the waste is well managed or discharged at the right place, they will cause significant
effects to soil/groundwater quality. Project owner will sign contract with the Ca Mau
Environment and Urban Company in order to collect and treat this waste. In general, the
solid waste from power plant activity is minor and less toxic, so the effect on the soil
environment and ground water is insignificant.

4.2.3 Impacts on Biological environment
Like the CM1 power plant, normal operation of the CM2 Power plant will not cause
considerable effect on the terrestrial environment. The normal operation will not cause
significant effects to the surrounding vegetation where is mainly rice field. The Vo Doi
specific forest is considered as the nearest place from the project area with distance of 8 –10
km. Therefore, the operation might only reduce the number of the birds, coming here for
food.
The considerable impact on the biological environment from the plant operation is on the
aquatic environment due to the cooling water intake. The added cooling water for the CM2
power plant is 1,440 m3/hour, will impact on the aquatic ecosystem as follows:
−   Effect of cooling water intake: Although the mouth of cooling water suction pipe is
    installed a bar-screen system with different hole sizes from 20cm, fixed net hole of 2cm
    and spin net with hole size less than 1cm. But the cooling water suction with velocity of
    0.3m/s could also entrain a number of organisms including zooplankton, phytoplankton,
    fish egg, larvae and young fish/prawn. It is impossible to forecast the exact influence of
    the cooling system to pulled organisms, but dead rate will be high, especially fish eggs;
−   Effect of cooling wastewater discharge: according to cooling water dispersion modeling
    result in the case of normal operation with cooling water discharge temperature of 35oC,
    the average temperature at discharge point will increase about 1.1oC. The slight
    temperature increase will not cause directly impact on aquatic ecosystem. In case of tail
    gas incident, the increment of average temperature will be about 2.2 – 2.4oC and
    maximum temperature will be about 8 - 9oC. The temperature increment will cause local
    thermal pollution around discharge points and increase the metabolism, the fast growing
    of some algae (for example green alga at 30 – 35oC and blue alga at 35 – 40oC) and
    cause effects on aquatic organism because the blue alga is a poor food.

4.3     DECOMMISSION PHASE
According to the basic design, the CM2 power plant will operate in 25 years. At the point of
the report reparation, there isn’t any detailed plan for the decommission phase. There are
two options might apply in the decommission phase:

CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      84


1. Partly removal: only some equipment units will be dismounted and moved away, other
   works can be preserved to reused for other purposes;
2. Wholy removal: equipment units will be dismounted and moved away.
Main environmental impact sources mainly concern with the commissioning and transporting
the plant and utilities. These activities will disturb the project area and obstruct other
activities at its vicinities. In addition, the decommissining of the Plant’s productive workshops
will generate a quantity of hazardous and non-hazardous waste including fuel oil, lubricant
scrap from used equipment, etc. Moreover, there are also domestic waste, wastewater
generated from the plant area.

Option 1: In case of partly removal, some following impacts can happen:
- Disturb the soil environment at the project area;
- Disturb the natural condition and environment at the plant area;
- Impact on the surrounding areas due to noise, dust, shining,.etc.
- Disturb all roads due to transportation..etc.
- Discharge debris of tanks, pipes, bricks..etc.
- Transporting filling material for gully before covering.
- Polluting soil and sediment in and around the project area depending on the future used
   purpose.
Option 2: In case of wholy transfer, environmental impact is similar to the above case,
however the impact level will be higher.
In general, environmental impact in this phase is similar to the one in the
construction/commissining phase but it occurs in a short time and slighter. Main
environmental impacts from two options like above mention as follows:

4.3.1 Impact on physical environment
1. Air quality
Decommission process of heat and electric mechanism equipment, gas pipeline system and
ultility equipment will generate a considerable quantity of residual hydrocarbon and chemical
fume in the equipment units and dust will pollute the atmospheric environment. However, the
decommission activities only occur in a short time (approximate 6 months) so the
environment impact is considered as temporary moderate level.
2. Water quality
The decomission of equipment units and chemical, fuel storage tanks can leak chemicals
and other pollutants into the adjacent river (new canal and Cai Tau river). Leakage of strong
acid or alkaline chemicals will cause suddend reduction of increment of pH in the water
column. In case of fuel oil leakage to water environment,the impact level is considered as
from minor to major depending on the leaked fuel volume.
Futhermore, domestic waste genrated in this phase may cause pollution on water
environment due to increasing of organic matter content.
3. Soil quaity
A few waste will be remained after commission. If not well managed, it will pollute the soil
from minor to major level in the project area. In case of removing and disconnecting the fuel
and acid/alkaline storage tanks, that will pollute the soil due to leakage or spillage. If the fuel
pipeline is left, it can longterm pollute the soil environment because of metal erosion and
decomposition.

CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      85


4.3.2 Impact on the biological environment
Decommission activities will impact on the aquatic and terrestrial biological environment.
Normally, the impact during the decommission phase on the biological is lower than one
during the construction/commission phase.

4.4     IMPACT ON THE SOCIO-ECONOMIC ENVIRONMENT
The Ca Mau Power plant construction will cause positive and negative impact on socio-
economical environment of Khanh An cummune in particular and Ca Mau Province in
general.

4.4.1 Impact on popualation and labour force distributtion
Movement and resettlement
All works for people migration and site clearance of Ca Mau Integrated Gas – Power -
Fertilizer area had been completed in 2001 by Ca Mau People Committee. Petrovietnam had
paid satisfactorily compensation for local people and finished since 2001. However, in order
to stabilize the living condition for local people in initial years, Petrovietnam had supported
the People Committee of Ca Mau Province and Khanh An Commune to build a temporary
resettlement area with 300 fourth level houses at Cai Tau K1 prison land, about 300m from
the power plant. Recently, ADB (capital loan bank for the project) inspected and interviewed
local people who satisfy with compensation.
The construction of new resettlement area is responsibility of Ca Mau People Committee.
Until now, new resettlement area was planned (Fig. 3.4) and divided into plots, dug
surrounding canal and built sluice to prevent fresh water for U Minh 3 farm.
Job and Training
During the site filling up process (2002), the project had used 100% local manpower. The
CM2 power plant implementation will need 1,500-2,000 workers in construction phase and
about 258 workers experts in the operation phase. The training program for local workers
also improves their knowledge/skill for the local labor force.
However, the current educational background of workforce in Ca Mau is not high, about
21.7% of population had already learned/graduated from high school and only 7 - 8% of the
population is skilled workforce. To meet a part of manpower demand of the plant, young
labor force of the province could be employed and joined short or long-term trained to
upgrade their skills to serve for the plant in the future. However, according to the complaint
of Khanh An People Committee (Secretary of Khanh An commune, 22/12/2005) the priority
norm of labor training for the Khanh An commune is not correspondent with the whole local
current labor force.
Thus, the execution of the power plant will cause the change of labor and occupation
structure in long-term at the area and form a more skilled workforce. Besides, construction
and development of the Ca Mau gas – power – fertilizer complex in general and the power
plant in particular will push the development of other industrial branches such as
transportation, services, commerce and industry. The project implementation will also
impulse development of the local economy, enhance living standard and educational
background of the local inhabitants.

Increase of population density
During the project implementation of the CM1 and CM2 power plants, there will be a number
of immigrating labors coming from other provinces. That will increase the population density
CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      86


in the area. The Khanh An population at 12/2005 is about 18,000 persons and according to
site survey result, the existing population density in the project area is not high, they only
concentrate along Cai Tau river. Therefore, construction of workforce camps during
construction phase will not affect to local land fund.
During construction phase, immigrating labors may cause some disturbances on the local
life. These effect may be positive, enhance the diversity and plentifulness for the local
culture. But, unless the local authority has a suitable management measure, the social evils
may occur and that will disturb strongly on the local living due to the different lifestyle, habit
and custom between the local residents and the project’s workforce. Several differences
between the immigrant and the resident may happen in the construction phase. However,
when the project comes into the operation phase, the project workforce will decrease (60%)
and most technical staff will stay in the project’s building at Ca Mau city. Therefore, the effect
of population increase is considered as minor level.

4.4.2 Impact on Agricultural development
The power plant construction will permanently lose 10ha of agriculture land of Khanh An
commune leading to the completely change of land use structure of hamlet 1 and effect
directly on all moved households. But if it is generally considered the project area had
already been changed land use purpose from agricultural to industrial land and land fund of
Ca Mau is large, therefore, when the plant comes into the operation phase, impact level on
the agricultural production is insignificant in comparison to benefits of the project for Ca Mau
province in the future.

4.4.3 Impact on industrial development
Up to now, Ca Mau province has several industrial branches such as aquatic product
processing for export, rice grinding, medium and small mechanisms, ship building and
repairing, foodstuff processing. The power plant execution will develop some industrial
branches such as mechanism, construction, commercial service, etc. That contributes an
important role in development of industrial production value in the area. The construction
and development of the adjusting Ca Mau power plant will contribute in renewing and
upgrading the whole infrastructure system of the area such as road system, enhancing
power supplier, building wastewater drainage system, communication, commercial and
service development, pushing up local industrial development and creating conditions for
development of other projects in the area.
The power plant 1 & 2 construction has used natural gas, pushing the development process
of petroleum and energy industry. In addition, the development and activities of main
industrial branches such power plant and other projects in Ca Mau industrial zone will create
job for other small industrial branches to serve plant’s maintenance and operation. That has
created many jobs and business investment chances for the local.

4.4.4 Impacts on transportation and infrastructure
    Waterway traffic
Ca Mau province has density waterway system cresting convenient condition for
construction material and agricultural good transportation from Ca Mau to other provinces
and vice versa. At present, Ca Mau has 4 interprovincial and 4 internal waterways. Those
main waterways play key role of the strategy for economic construction and development of
the province.
During the site filling and consolidation for the project area, most sand and constructive
material will be transported from Can Tho City to the plant (198km) by barge of 100 –
200tones/barge or large-barge of 80 tones/boat. Thus, estimated time for sand
CPMB– RDCPSE-Final report                                                                       June, 2006
Revised report on DEIA for Ca Mau power plant project (Part of DEIA for Ca Mau 2 power plant)      87


transportation is about 16 months, the estimated number of boat/barges transporting over
the waterway Can Tho – Trem river – Cai Tau river is about 100 barges/day and about 90-
100 barges/day back and forth the Cai Tau area.
During the construction and installation phase, cement will be transported from Kien Giang
through Kien Luong – Xeo Ro – Trem – Cai Tau. Steel, super-weigh and super-size will be
transported by barge of 300 tones following Can Tho – Ca Mau or Ho Chi Minh – Can Tho –
Ca Mau. The estimated number of barges passing temporary port is about 15 – 20
barges/day during 18 – 24 months. The transporting of these materials will increase
waterway traffic density over the main route (Trem River) and Cai Tau confluence, leading to
the waterway and increment of collision risk on the canal/river system. The impact level is
assessed at moderate level during the plant construction phase.
During the operation phase, normal boat density is low at the DO unloading jetty (the highest
is once per day) but that also lead to the increment of boat density and collision risk at port
area.

    Road traffic and infrastructure
Beside the plant construction, PetroVietnam has cooperated with Ca Mau People Committee
to construct infrastructure system for project activities and local resident such as the road
system 14.5km long from Ca Mau city to the gas-power-fertilizer complex; installation of
power supplied network, wastewater drainage and communication system etc. These
activities will make the completely change of the area’s infrastructure from no internal road to
interprovincial roads that give good condition to enhance living standard of local resident and
create favorable condition for national and foreign investors into Ca Mau as well as pushing
the industrialization and modernization of Ca Mau province in the future.

4.4.5 Impact on aquaculture and fishery
According to the site survey result about the fishery existing status along Cai Tau river in Jan
2003 and Dec 2005 showed that almost agricultural households living along Cai Tau river (1-
3km far from the plant) changed into ecological spawn 1 crop (in the dry season) since 2003
over their rice fields with low prawn productivity.
Due to the cooling water from the revised power plant project (CM1 and CM2 power plants)
is evaluated as clean wastewater, so the regular water intake of 2m3/s supplemented cooling
water and discharge 0.8 m3/s directly into Cai Tau river of the two plants will not cause
significant effects to Cai Tau river aquatic ecosystem, it just locally affects at discharge site
(average temperature increasing of 1.1oC and maximum temperature of 3.5oC in comparison
with the river’s current temperature (28oC)). Therefore, discharge cooling water will not
cause any significant impact on the aquacultural activities along Cai Tau river.
According to diluting wastewater model had showed at section 4.2.2.2, the discharging a
treated wastewater (0.008m3/s) of both plants into Cai Tau river will cause insignificant
impact on the aquacultural area due to the small wastewater and located out of the
aquacultural area (Ong Doc river downstream) and ecological prawn area (Cai Tau river
downstream).
According to the evaluation of Ca Mau Fishery Department (June,2002 and December,
2005), catching fish activities on the river/canal surrounding the project (Ong Doc, Trem, Cai
Tau rivers) is insignificant, about 6 fixed bottom nets at Ong Doc river and no net on Cai Tau
and Trem river up to June, 2002. Therefore, the project operation will not cause any impact
to fishing activities of local people.
It is noted that before having presence of CM1 and CM2 power plants, the Cai Tau river’s
water quality at the water intake point (VT0) in two measuring times: dry season 2002 and
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dry season 2005 has tendency decreased due to discharging wastes from Cai Tau
residential area and Ngoc Sinh aquatic product processing company on the K21 canal.

4.4.6 Impact on public health
During the construction and installation phase, noise generated from operation of vehicles,
and other construction equipment will cause noise that can affect to human health at
construction site and adjacent area.
The considerable emission of natural gas during the commission or commission will directly
effect on the workers who work on site project area such as headache and dizzy. However,
the gas venting is only carried out when the system is over-pressure and volume of venting
gas is very small, so affected level on the workers who operate the plant is assessed as
minor.
Health care
During the construction phase, temporary camp areas are supplied clean water and hygiene
equipment. If wastewater is not adequately treated and directly discharged into the river, it
will cause waterborne diseases such as cholera, dysentery, and typhoid. According to the
project plan, there is a public health station for taking care the project’s employees and
assisting in checking up health sickness for local resident in necessary.

4.4.7   Impact on culture and landscape
Accompanying to the activities of Ca Mau 1 power plant, the activities of the power plant 2 at
Cai Tau confluence - Khanh An commune will change the area’s landscape (view
obstruction, noise, etc). The landscape will completely be changed from rural area to modern
industrial zone. Light system from work units on the night that irritates to the local people and
destroys the harmonious landscape of the pure rural countryside.

Although Ca Mau province has a lot of protected areas with beautiful natural landscape,
ecological tourist areas attracting visitors but project area is pure rural one and there is not
any protected area or bird ground. Vo Doi specific forest is considered as the nearest place
from the project area, but it is 8.5km far from the plant. All plant’s activities will not only
cause effect on the special-use forest but also impulse the service activities for tourist
development.
In summary, construction and development of Ca Mau adjusting power plant will change the
landscape because the plant’s activities and impact level is assessed as moderate during
the project’s life times.

4.4.8   Impact on economy
The revised Ca Mau power plant project is one of Vietnamese strategic projects with high
efficiently natural gas utilization from southwest gas fields to produce and satisfy additional
charge power demand in the future. The plant’s development has pushed up the area’s
economic development and enhancing industrialization and modernization process of the
country as well as increasing attraction of foreign investment at Ca Mau province.

The project’s development is strongly pushing up, stimulating and exchange economic
structure. It contributes an important socio-economic living enhance and securely keeping
the politics-security for fatherland’s southwest area.




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Section        5.
PRELIMINARY ENVIRONMENTAL
RISK ASSESSMENT

Environmental risks generated during implementation of the Ca Mau 1 power plant have
been assessed primarily in the DEIA report for the Ca Mau 1 power plant. The additional
construction of Ca Mau 2 power plant in the planned land for Ca Mau fertilizer plant of the
Ca Mau gas - power fertilizer complex will increase risks of accident occurrence in the area
as well as change environmental impacts when the accident occurs. Purpose of this section
is to identify potential dangers and risks, which may occur during the implementation of the
Ca Mau 2 power plant project, to qualitatively and quantitatively calculate risk possibility
(with available data) as well as to identify effects on people, equipment and environment
upon accident occurs in the Ca Mau 2 power plant. Here, changes in the environmental risks
during the operation of the Ca Mau 1 power plant when the Ca Mau 2 power plant exists will
also be considered. These assessments will help to have overall view on the project security
in order to get appropriate mitigating measures in the project design and operation. More
detail risk analysis and assessment about the project equipment and operation manual will
be mentioned in separated reports during the project detail designing.

5.1     SOME HAZARDOUS PROPERTIES OF FUELS USED IN THE PLANT
The main fuel of Ca Mau 2 power plant is natural gas exploited from Southwestern gas fields
including from block PM3 in period 2003 - 2015 and then supplemented from Cai Nuoc field.
The natural gases are composed mainly of alkanes from C1 to C5 with methane content of
approximately 77.95% wt. Besides, the natural gases also contain 7.53% mol. of CO2 and
almost no hydrogen sulfide. In case the natural gas supply is interrupted, the power plant will
use stand-by fuel as imported diesel oil (DO) with maximum sulfur content of 0.5%wt.

1. Natural gas

Some concerned hazardous properties of natural gas are:
-   Natural gas exists in equipment under high pressure, so when leakage occurs, gas will
    be quickly escaped out and be difficult to control;
-   Natural gas is flammable and form flammable mixture with oxygen when they are leaked
    into atmosphere. Limits of flammable mixture forming in the air of some alkanes are
    shown in Table 5.1.
    When the flammable mixture is formed (flammable gas content in the air is in the range
    between low flammable limit (LFL) and upper flammable limit (ULF)), it may fire even
    with very little ignition (e.g. a electric spark). If firing process occurs inside a closed
    system, gas mixture will be heated and strongly expanded, inside pressure will be
    increased suddenly and lead to explosion, which is very dangerous for people and
    equipment in the affected area.
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        Table 5.1    LIMITS OF FLAMMABLE MIXTURE FORMING OF SOME ALKANES

                                  Low flammable level (LFL)                 Upper flammable level
          Alkanes
                                         (% in the air)                         (% in the air)
    Methane (CH4)                             5.0                                    15.0
    Ethane (C2H6)                             3.1                                    15.0
    Propane (C3H8)                            2.1                                     9.5
    Butane (C4H10)                            1.6                                     8.5
    n-Hexane (C6H14)                          1.2                                     7.4
Source: [16]

-     Due to natural gases are heavier than the air, therefore once released, natural gases
      always drifts downwind and accumulates at lowest areas;
-     Natural gas density is only about half of the water density, so it always floats on the
      water surface.

      Methane

Methane is very flammable and creates colorless flame, secondary pollutants such as COx,
THC and soot when be burned. Methane is assessed as low toxicity to creatures. However,
people and animal will be dizzy or unconscious when respires a lot of methane. Very high
concentration of methane in the air will lead to reduce oxygen content under respirable
threshold and cause human and animal death. Methane content in the air of over 4.5% will
cause suffocation due to lack of oxygen. Poison symptoms like convulsion, suffocation,
pneumonia, lung abscess. When methane content in the air very high (over 40,000 mg/m3
equivalent to 5.6%) will decrease oxygen content to under respirable threshold and at
content of over 60,000 mg/m3 (equivalent to 8.4%) will cause convulsion, respiratory and
heart disorders, even lead to deaths of human and animals [17].

      Carbon dioxide (CO2)

Carbon dioxide is a colorless, odorless gas with a faint acid taste. CO2 is existed in the
normal atmosphere at concentration varying from 0.03% to 0.06%. At concentration of 5%,
CO2 in the atmosphere may cause shortness of breath and headache. CO2 with
concentration of 10% in the air can produce unconsciousness for exposed people and lead
to death from oxygen deficiency. CO2 does not give a warning of its present in an
asphyxiating concentration and a person may unwittingly enter a confined space or descend
into tank or vessel and be overcome before he becomes aware of the danger and can not
make his escape.
Concentration of CO2 in the air and correlative consequences are summarized in Table 5.2:
       Table 5.2     CO2 CONTENT IN THE AIR AND CORRELATIVE CONSEQUENCES

        Concentration of CO2 in the air (%)                            Consequence
                       0.15                              May cause shortness of breath
                    0.3 - 0.6                            Unable to work
                       3-6                               Fatality danger
                      8 - 10                             Headache, visual trouble, Asphyxiated
                     10 - 30                             Immediate asphyxiated
                        35                               Dead
Source: [17]




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2. DO

Diesel oil (DO) is a petroleum distillate belonging to medium fraction, light color and its main
components include paraffin, olefin, naphthalene and hydrocarbons. DO has flash point over
60oC and boiling point in the range of 163 – 371oC. Aromatic hydrocarbon content is quite
high, occupied 20 – 30% volume. That is one of the oil features causing toxic to the
environment. Besides aromatic hydrocarbon, sulfur (0.1 – 0.5% wt.) and nitrogen are high
toxic compounds, which need to be paid attention during environmental impact assessment
and overcoming the accidental consequences.

DO can be expected to spread on the water surface, evaporate, disperse, dissolve and dilute
in first hours released into environment. DO is highly biodegradable (Hinchee et al, 1995a
and 1995b). The water-soluble fraction is more readily available to microorganisms and it
can be expected to degrade relatively rapidly following spillage into environment. Various
environmental factors including temperature, oxygen concentration, nutrient availability and
salinity of water environment will influence of the rate of degradation.

DO is high toxic. Results of toxicity test on Artemia and Penaeus monodon (larvae) of
commercial DO in Vietnamese market shown that, even at the oil concentration of 10 ppm,
some responses showing the toxic effects of diesel oil on Penaeus monodon were recorded:
decrease in swimming, 10% lethality. At the oil concentration of 80ppm, approximate 96% of
Penaeus monodon died after 4 days exposing in polluted oil.

5.2     RESOURCE SENSITIVITY ASSESSMENT
5.2.1 Identify affected area

The configuration of the CM2 power plant is the same as that one of the CM1 power plant, of
which some equipment systems are used for both plants such as cooling water intake and
discharge system, DO loading port. Therefore, in the operation of the Ca Mau 2 power plant,
the most severe accidents that might occur include gas leakage (natural gas), fire/ explosion
accidents if fire source exists, and DO spillage from DO tanks inside the plant. These
accidents, especially fire/ explosion will cause severely effects to human, equipment and
environments.

Affected area when accident occurs depends on nature of each accident, environmental
conditions, etc. Summary of affected areas are as follows:
♦   Gas leakage: Leaked gases will disperse into the atmosphere and will affect mostly the
    plant area. Their effect may reach to the CM1 power plant area, Cai Tau prison area and
    surrounding residential areas within radius of 1000m toward to wind direction;
♦   Fire and explosion: affected area mainly is the plant area. The affected area may be
    larger in terms of covered area of smoke and dust when accidents occurs (within radius
    of 1000m);
♦   Oil spill: spilled oil from DO tanks in the CM2 power plant will generally affect
    insignificantly the environment due to the DO tanks are laid in the area surrounded by
    bunds. However, if oil spills during DO loading/ unloading, K21 canal and Cai Tau river
    may be affected.

Generally, in case that an accident happens, the Ca Mau 2 power plant area will be mostly
affected and the area of Ca Mau 1 plant will also more or less be affected.




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5.2.2 Sensitivity assessment of affected areas

Environmental sensitivity can be determined by assessing biological resources, topography,
geomorphology and socio – economical activities in the area.

The CM2 power plant construction area is located in Northwestern corner of the land
planned for Ca Mau fertilizer plant construction. The North of the plant is bordered with CM1
power plant, the West - with Cai Tau jail, the East and South will be bordered with Ca Mau
fertilizer plant. According to Ca Mau province planning, the Ca Mau gas - power - fertilizer
complex will be located within Khanh An industrial zone of the province in future.

Residential areas are quite closed to the plant: Northern of the power plant No. 1 is
residential area of hamlet 1 – consisting mainly of residential houses, orchards (coconut)
and ornamental plant. Vegetation cover in left bank of Cai Tau river is mainly water coconut
(Nipa). Residential area of hamlet 10, resettlement area and a part of U Minh 3 farm land
consisting mainly of agricultural land and small replanted Eucalyptus forests locate
adjacently to the Cai Tau jail in the west of the plant. Residential area of hamlet 4 and
resettlement area locate in the Cai Tau confluence in the northeast of the plant. Residential
area of hamlet 6 is adjacent to the South fence of the fertilizer plant. Further are residential
areas spreading along two banks of Minh Ha canal. Here are about 1000 ha of 1 shrimp
crop, which is transferred from rice fields by local residents. The environmental sensitivity
indexes are assessed from medium to high.

5.3     DAMAGE ASSESSMENT OF ACCIDENTS
During operation of the Ca Mau 2 power plant, dangers and risks including gas leakage, fire/
explosion and oil spill may occur.

5.3.1 Gas leakage in the plant

5.3.1.1 Possibility of gas leakage
Gas fuel using for the plant will be supplied to the plant's fence by pipeline. As planned,
natural gas volume using for the power plant is about 2.1 ÷ 2.4 million m3/day. From the
plant's fence, gas will be directed to the turbines via the gas supplying system consisting of
emergency shutdown valves, liquid separator, cold vents, measurers, filters and heaters.
Gas may be leaked from valves, flanges, and gas treatment equipment as well as from gas
pipeline in both operation and maintenance processes by many reasons as follows:
- Internal corrosion: If water presents inside the pipeline, corrosion will occur due to the
    reaction between carbon dioxide and water, which may still present in the gas flow,
    forming acid leading to corrosion;
- External corrosion;
- Corrosion caused by pipeline unstable structure or mechanical damages including the
    damage of material, weld, connection, etc.;
- Abnormal situation such as the overpressure inside the pipeline, equipment, etc.;
- Outside effects caused by sabotage, gas theft and other construction activities along the
    pipeline;
- Natural calamity: séisme, depression, etc...
At the time of the report preparation, detail design of the gas supplying system is not yet
available, therefore, possibility of gas leakage could not be calculated exactly. Estimated
possibility of gas leakage occurrence from the main equipment of the gas supplying
system and the gas turbines are summarized in following table:
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       Table 5.3     POSSIBILITY OF GAS LEAKAGE IN THE CA MAU 2 POWER PLANT
                                                Frequency                       Frequency
                                                                                                 Source
                   Equipment                       of gas        Quantity         of gas
                                               leakage/ unit                     leakage
    Leakage from gas pipeline                    4.9 x 10-5        150m         7.35 x 10-3
    Leakage from ESV                             7.3 x 10-4          1          0.73 x 10-3
    Leakage from liquid separator                1.9 x 10-3          2          3.80 x 10-3
    Leakage from measuring equipment             2.3 x 10-4          2          0.46 x 10-3
    Leakage from filter                          3.6 x 10-3          2          7.20 x 10-3
    Leakage from gas heater                      3.0 x 10-3          1          3.00 x 10-3
                                                                                                OREDA-
    Leakage from gas turbine                     4.6 x 10-4           2         0.92 x 10-3
                                                                                                97
                                       Total                                   23.46 x 10-3
Notes: OREDA: Offshore Reliability Data

Therefore, probability of gas leakage during the operation of Ca Mau 2 power plant is
approximately 0.023 times/year.
After the gas leakage exists, leaked gas/ vapor may mix with air to form flammable mixture,
which will lead to fire/explosion accident only in case that flame source exists. Therefore,
probability of changing one gas leakage to fire/explosion accident practically is very low.

5.3.1.2 Environmental damages
Dispersion of leaked gas will be identified by SAFETI Micro Version 5.31 model. Here, only
the worst gas leakage case as gas pipeline broken is modeled. Gas dispersion results of the
SAFETI model running are summarized in Table 5.4.
                Table 5.4         GAS DISPERSION RESULT BY SAFETI MODEL

      Distance from          Natural gas content           Concentration of            Concentration of
       leaked point               (% mol)                   CH4 in the air              CO2 in the air
           (m)                                                 (% mol)                     (% mol)
            10                       50.60                      39.44                       3.81
            20                       34.23                      26.68                       2.58
            25                       28.03                      21.85                       2.11
           38.3                      20.00                      15.59                       1.51
           51.1                      15.70                      12.24                       1.18
           128                        6.76                       5.27                       0.51
          157.8                      5.51                        4.30                       0.41

Concentration of CH4 within upper (UFL) and low (LFL) flammable levels of 15% and 5%
respectively, which may potentially cause fire/ explosion, are found within radius 40 ÷ 200m
from leaked point. And CO2 concentration that may be dangerous for human life are within
radius of 10m from leakage point. Therefore:
−     If accident occurs in the gas pipeline section from connect point between the power plant
      and gas supply next to the plant western fence, leaked gas will affect the plant
      administration area and may reach to Cai Tau jail area located next to the plant fence.
−     In case that the gas pipeline is broken at other section, at gas treatment and distribution
      station or at two gas turbines, released gas will only affect to the CM2 power plant area.
Generally, leaked gas will cause direct effects on project workers working in the plant.
Environmental impact caused by gas leakage is considered as minor. With probability of gas
leakage occurrence at medium level, environmental risk of gas leakage accident is assessed
as minor and acceptable.
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5.3.2 Fire/ explosion accident
5.3.2.1 Risk of fire/ explosion accident
During operation of CM2 combined cycle power plant,following typical accidents may
happen:
-   Fire/ explosion accidents generated by short circuit in main electrical equipment such as
    power generators, transformer, electrical lines. etc.
-   Fire/ explosion accident caused by gas or fuel leakage: usually occurs at gas received/
    delivered place, turbine covers, combustion chamber, gas filters, fresh and waste fuel
    tanks, etc.
Probability of fire/ explosion caused by short-circuit is actually very small. Up to now, there is
almost no fire/ explosion caused by short-circuit in power plants. Therefore, only fire/
explosions caused by gas or fuel leakage are discussed hereinafter.

1. Fire accident
The main fire accidents are classified as follows:
Flash fire: Flash fire occurs with rapid rate of gas mass. It usually is fatal for anyone within
or near to the flame. It occurs rapidly, so it will not damage to facilities presented in the
incident area;
Jet fire: Jet fire is a high intensity fire with flare type caused by gas or gas/fluid stream
leakage under high pressure, released gas has spurt type and flame up. It is usually fatal for
anyone within it and major damage to facilities within the flame.
There is one special case of jet fire - impinged jet fire. Impinged jet fire occurs when leaked
gas stream clashes into obstacles and forms a whirled vapor cloud. The formed whirled
vapor cloud trends to disperse and quickly mix with air by the leaked gas stream dynamic. If
the vapor cloud is fired, it will form high intensive fire.
Pool fire: Pool fire is a fire on the surface of a pool of flammable liquid, which may occur
either from a large rapid release or following a continuous liquid release. As with the jet fire,
it may be fatal for anyone within or near to the flame, and may damage or destroy any
properties within the flame.

2. Explosion accident
Explosion is a process related to pressure wave formation generated from very quick energy
freeing. Explosion accident type are described as follows:

Vapor cloud explosion (VCE)
Vapor cloud explosion can occur because of the combustion of a gas cloud, which is whirly
distributed in the air. Whirled vapor cloud will accelerate the combustion process until the
expanding cloud of combustion gases generates an appreciable overpressure and
explosion. There are two types of vapor cloud explosion as follows:
-   Unconfined vapor cloud explosion (UVCE) – this is a vapor cloud explosion occurred in
    open area. Normally, all UVCEs would not cause significant shaken effects due to vapor
    clouds will be combusted as eddy flame with high heat radiation.
-   Confined vapor cloud explosion (CVCE) – this is vapor cloud explosion generated within
    small or closed space such as in tanks, drums, and pipeline or in closed building. This
    type of explosion usually creates strong shaken effects, which may destroy surrounding
    projects.
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Two unconfined vapor cloud explosion and confined vapor cloud explosion explosions may
be fatal to anyone within it and cause significant damage both within and beyond the region
of the cloud.

Boiling Liquid-Expanding Vapor Explosion (BLEVE)

Boiling liquid-expanding vapor explosions most likely occur in fluid tanks under pressure.
These accidents start with a fire outside the tank and the flame heat the fuel tank. At that
time, liquid inside the tank will be boiled, evaporated and expanded leading to increasing
vapor pressure inside the tank. When pressure exceeds the acceptable limit, the tank will be
ruined and cause explosion. Besides, liquid fuel is flammable compound, its vapor releases
out at high temperature and pressure, which will easily form a fire ball and continuously be
burned by existing flame in the tank surrounding area. In case of the power plant, BLEVE
accident may occur in the DO tank.
Fire and explosion accidents. which may occur in the power plant are given in Table 5.5.
                 Table 5.5 SUMMARY OF FIRE AND EXPLOSION ACCIDENTS
                                 IN THE POWER PLANT

           Accident type                    Cause                    Accident occurred place
                                      CH4 (natural gas).        In gas pipeline to turbines, gas filter
 Fire
                                      DO                        station, DO storage tank area
 Vapor cloud explosion (VCE)          CH4 (natural gas).        In gas pipeline to turbines, gas filter
                                      DO                        station, DO storage tank area
 Boiling liquid expanding
                          DO                                    DO tanks
 vapor explosion (BLEVE)

Generally, leaked gases are easier to be fired than leaked DO because they spread more
quickly and consists of many compositions with lower flash point. Most serious fire/
explosion accident, which may happen in the power plant, is the gas pipeline broken to the
turbines. In this case, gas released volume is biggest.

5.3.2.2 Environmental damage
Fire/ explosion accident will cause severe impacts on human, environment and damage
equipment, and facilities.
1. Impacts on personnel
The main effect mechanisms on human caused by fires/ explosion accidents includes:
−  Thermal impacts include thermal radiation and convective heat. The degree of damage
   caused by thermal radiation is related to both the intensity of incident radiation flux and
   the time for which a person is exposed. Thermal radiation of greater than 37.5 kW/m2 will
   cause instant lethality (Table 5.6). However, such level threshold is quite high and
   unlikely to reach (only exceptional catastrophes).

                 Table 5.6        EFFECTS FROM THERMAL RADIATION [18]
        Thermal radiation
                                                                 Effects
          criterion level
          37.5 kW/m2           Immediate fatality
          12.5 kW/m2           Extreme pain within 20 seconds
           4.7 kW/m2           Can bear for 15 – 20 seconds. harmful after 30 seconds contact
           2.1 kW/m2           Can be exposed for 1 minute
           1.2 kW/m2           The same as sun shinning effect in summer noon
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−   Impacts of smoke: smoke comprising of toxic gases such as CO (main content) NOx and
    SO2 depends on the materials burnt, and leading to oxygen depletion and impaired
    visibility. CO is usually the main cause of death in fires. The effects of CO2 on the human
    body are two levels. Firstly CO2 will cause toxic effects when present in concentrations
    greater than 3%. Secondly CO2, when absorbed into the blood stream acts as a trigger
    to the brain to increase the breathing rate in order to draw more oxygen into the lungs.
−   Overpressure explosion: an overpressure of 0.2bar (2.9psi) is adopted as the limit for
    causing fatality, i.e. all personnel inside the overpressure region of 0.2bar will die
    whereas no fatalities outside this region will occur. For those personnel trapped within a
    combustion cloud, regardless of the overpressure a 100% fatality rate is adopted as
    personnel will be caught in the flame.

2. Failures to Equipment

Times to failure for an unprotected steel beam are 5 minutes under jet flame (250 kW/m2).
10 minutes under pool fire (150 kW/m2) and 30 minutes under thermal value of 37.5 kW/m2
while times to failure for pipeline and vessel are 5,10 and 60 minutes respectively [18].

If steel pipeline contains liquid under pressure, are heated in the fire, the pipeline and liquid
temperatures increase. These impacts will reduce the pipeline durability, thermal stretching
of pipeline section between two connected points make pipeline bend down, lessen pipe
rack durability and damage flanges (Table 5.7).

                         Table 5.7         OVERPRESSURE EFFECTS [18]

    Overpressure
                                                               Effect
        level
      0.35 Bar          Heavy damage to factory, building and technological equipment
                        Cause repairable damage for factory, building and technological
       0.1 Bar
                        equipment
      0.05 Bar          Cause window glasses broken and human injure
      0.02 Bar          10% window glasses broken

Here, only the worst case as fire/ explosion occurring due to gas pipeline from gas filter
station to turbines broken is modeled. Results of the SAFETI Micro model running in this
case are as follows:

         Table 5.8      AFFECTED SCALE OF FIRE/ EXPLOSION BY SAFETI MODEL

       Fire/ explosion type                    Effect level and extend
 Jet fire
 - Thermal radiation (kW/m2)           10               20                                  37.5
 - Distance (m)                      261.5            241.0                                224.4
 Flash fire                                        Extend 444 m
 Boiling liquid expanding vapor explosion (BLEVE)
 - Thermal radiation (kW/m2)          4.0              12.5                                 37.5
 - Distance (m)                      195.8            112.5                                63.44
 Explosion with early ignition
 - Overpressure (bar)                 0.02             0.14                                 0.21
 - Distance (m)                      342.3            183.4                                170.9
 Explosion with late ignition
 - Overpressure (bar)                 0.02             0.14                                 0.21
 - Distance (m)                      339.8            182.9                                170.4

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According to model results in case of fire occurrence:
-   If jet fire accident occurs in gas pipeline section from the plant fence to gas treatment
    and distribution station, it will cause critical harm to people presented in the whole plant
    area, especially in administration area. Overpressure effect also reaches to Cai Tau jail
    and the power plant administration areas;
-   If jet fire accident occurs near the gas treatment and distribution station or in pipeline
    section from the station to the turbines, the main affected area will limit within the CM2
    power plant. The Cai Tau jail and the CM1 power plant areas will also be affected in
    lower level. The most serious is effect of thermal radiation on DO tanks, which may lead
    to BLEVE accident;
-   In case of flash fire, the flame may spread to the Cai Tau jail, CM1 power plant and
    Fertilizer plant.

Explosion accidents will affect mainly the power plant area due to thermal radiation and
overpressure intensities usually quickly reduce by distances. Overpressure effect may occur
in the CM1 power plant (at administration building and DO tank areas) in case of explosion
with late ignition in gas pipeline running next to the plant fence. The power plant is
constructed far from residential area (these residential areas themselves are thin
population). Thus, occurred fire/ explosion would not affect adjacent residents. However,
thermal radiation may affect crop productivity of some rice fields adjacent to the power plant.

In case of fire/ explosion accident, a big volume of unburned CH4 and combustion products
such as CO, NOx, organic peroxide and dust will disperse into atmosphere. These are main
pollutants, which diminish air quality and may affect to human and fauna health. However,
when accident happens, high concentration of these air pollutants in the atmosphere will
only exist locally within the plant and in short period of time. These air pollutants will disperse
quickly by wind effect and their concentration in the air will reduce under toxicity level. Thus,
impacts on environment caused by fire/ explosion are only as minor and short-term.

Thus, consequence of fire/ explosion accidents in the CM2 power plant is assessed as
significant. However, possibility of fire/ explosion accident occurrence during the Ca Mau
power plant operation is only at minor level. Therefore, environmental risk caused by fire /
explosion accidents during the operation of CM2 power plant will only be at moderate level,
but already reached the limit and should have risk monitoring and mitigating measures.

5.3.3 Oil and chemical spills
5.3.3.1 Chemical spills
During the power plant operation phase, following main chemicals will be used: caustic soda
(NaOH 30 or 50%), sulfuric acid (H2SO4 98%), hydrochloric acid (HCl 33%). These
chemicals will be delivered to the plant by tank trucks. Chemical loading from the trucks to
storage tanks may cause chemical spillage into environment. In addition, chemicals may
also be leaked from storage tanks, pumps, pipelines, etc. However, there are impoundment
dyke around chemical storage tanks in the plant and under tank bottoms are waterproof
layers. Spilled chemicals will be collected and would not be released into environment.
Therefore, chemical spill accident would not cause significant impact on environment.
Although, chemical spill may threaten people due to these are toxic chemicals, which may
cause skin burn, raspy throat, etc. The plant operators have to be equipped with protective
clothing and to grasp thoroughly first aid action when being chemical adhesion.




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5.3.3.2 Oil spills
♦   Risk of oil spills

Oil spill causes during the power plant implementation include:

                   Table 5.9 POTENTIAL OIL SPILLS IN THE POWER PLANT
                            AND THE DO IMPORTING JETTY AREA

                                                                                    Spilled oil Quantity
    No.                                    Causes
                                                                                     to environment
    1       DO tanks leaked/ broken                                                        Little (*)
    2       Leakage upon DO transferring from the DO jetty to the                       Insignificant
            storage tank area
Note: (*) DO storage tanks are placed inside impoundment dyke which can contain 110% tank capacity, so that
           spilled DO will be kept inside and release probability into the environment is very little

Generally, spilled oil volume into environment at oil spill accident in the power plant No. 2 is
small, but the storage tanks located next to the canal K21 and the project area has dense
river/ canal system, therefore, oil spilling into the river/canal environment will cause
significant impact.
♦   Environmental damage
Spilled oil into environment will evaporate, dissolve into water column, settle down into
sediment surface and oil film spread on water surface. During the oil weathering process,
the oil toxicity is reduced due to evaporating of the toxic compounds, particularly the
aromatics with low boiling points (benzene, toluene, xylen, and ethylbenzene). If the
evaporation is obstructed by natural dispersion, the dissolved amount of toxic components in
water will increase. Low energy shoreline and sheltered areas are most likely at risk. Also
possibility of accumulating higher concentrations of oil components will increase the risk for
sheltered and shallow water.
Because of the project area is confluence of 3 main rivers such as Ong Doc river, Cai Tau
river and Trem river, it will be influenced by both Western tide from Ong Doc river mouth and
Eastern tide from Ganh Hao river via Tac Thu canal. Eastern tide is semi- dual regime, and
Western tide is dual one. Furthermore, tidal regime in Ong Doc river mouth and Rach Gia
are not phasing synchronic. Current regime in the project area is very complicate. Oil spilled
into the water environment will affect planktons, benthos, fishes and larva. Spilled oil also
severely affects mangrove trees along the Cai Tau riverbank and aquacultural activities in
the area. Impacts of oil spill into water environment have already assessed detail in DEIA
report for the Ca Mau 1 power plant.

Besides, when spilling into the environment, DO quickly evaporate. There are aromatic
compounds in the DO vapor, which are very toxic. Light molecules with higher toxicity will be
evaporated quicker. Constituents with boiling - point of under 200oC can evaporate entirely
within 24 hours. DO vapor released into the environment will cause very strong and
unpleasant odor leading to eye smarts and tearing. Evaporated organic substances cause
eye smarts, respiratory trouble and may cause skin diseases for human at high
concentration, forming photochemical oxygen, which thin ozone layer of stratosphere. Thus,
in case that DO spill occurs at the DO tank area inside the Ca Mau 2 power plant, it will
directly affect the plant workers, administration area of Ca Mau 1 power plant and fertilizer
plant (if being constructed here). However, impacts on air quality will occur only in short
period of time.

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Chapter        6.
MITIGATING MEASURES FOR
ENVIRONMENTAL IMPACTS
Mitigating measures for adverse environmental impacts created during constructing and
operating processing of Ca Mau 2 Power plant will be promoted in this chapter to ensure
clean environment as well as sustainable development process. These mitigation measures
base on improvements and adjustments of technology, management process and/or actual
activities. They will be mentioned below, following development phases of the project and
adverse environment impacts which need to be mitigated.

6.1     MITIGATING MEASURES DURING CONSTRUCTING
        INSTALLING, COMMISSIONING PHASES
Mitigation measures during construction, installation, commission phases are promoted as
follow:

6.1.1 Soil quality
The main purposes of mitigation measures on soil quality impact in construction area are:
- Prevent soil erosion.
- Prevent soil pollution from fuel assembling zone.
- Reduce impact of solid waste.

No      Object/ Aim      Mitigation measures                                           Remain
                                                                                       impacts
A1      Prevent          Planning for surface leveling and consolidation in dry None
        erosion          season, limiting consolidate time.
A2      Prevent          Gravel, construction materials and stone will be None
        erosion          spreaded on the roads where construction materials and
                         super heavy equipment are transported.
A3      Soil             Setting water-proof material layer below tanks to prevent None
        pollution        pollutions.
A4      None             Contract with Ca Mau Water Supply and Urban Facilities None
        hazardous        Company for daily collecting and transporting to landfill,
        solid waste      9km far from project zone.
A5      Hazardous        Contract with Ca Mau Water Supply and Urban Facilities Local
        solid waste      Company for periodic collecting (paint, solvents, oil filter, impact in
                         engine oil, wasted oil, weld stick, etc.) into safety tanks landfill only
                         which marked clearly before transporting to the landfill
                         stipulated by DONRE of Ca Mau.


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6.1.2 Air quality

The main purposes of mitigation measures on ambient air quality impact in constructing
zone are:

-    Minimize emission factors such as dust, SO2, and VOC to atmosphere from means and
     equipments served for construction.
-    Minimize impacts of noise to residential zone.
-    Prevent respiratory diseases.

No      Objects /          Mitigation measures                                      Remain impact
        Purpose
                                                                                    Insignificant
B1      Exhaust from       Only use transportation means registered to
        means of road      meet legislative standards (TCVN 5947:1996)
        transportation
                                                                                    Insignificant,
B2      Dust               Maintain spraying water frequently on
                                                                                    met TCVN 5937:1995
                           constructing site, assembling material zone
                           and center of transportation (especially in dry
                           season).
                                                                          Insignificant,
B3      Dust               Using cover material on transportation means
                                                                          met TCVN 5937:1995
                           to transport construction equipment.
                                                                          Insignificant,
B4      Noise              Arranging working time logically to avoid rest
                                                                          met TCVN 5949:1998
                           time of residential zone, restraining of
                           transportation in rush hour. Stipulate
                           transportation speed for vehicles (<30km/h)
                           to minimize noise generated, especially as
                           passing through residential area or rest hours
                           of residents.
                                                                          Insignificant,
B5      Dust, noise        Maintaining frequently vehicles and
                                                                          met TCVN 5949:1998,
                           constructive equipment to minimize noise,
                                                                          TCVN 3985:1999,
                           vibration and exhaust.
                                                                          TCVN 5937:1995
                                                                          Insignificant,
B6      SO2                Using low sulfur fuel (<0.25%) for vehicles
                                                                          met TCVN 5937:1995
                           and equipments.
B7      Prevent from       Well ventilation for working areas created               None
        respiratory        dust and exhausted gas such as welding,
        diseases for       paint spraying, warehouse and supply safety
        labour             individual equipment suitable for workers as
        workers            hamlets, masks, protective clothes…


6.1.3 Water quality
The main purposes of mitigation measures on water quality impact surrounding the
constructing zone of the plant are:
-    Prevent groundwater pollution at material assembling zone supported construction
     works.
-    Minimize adverse impacts to surface water.


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                                                                                         Remained
No      Object / Aim       Mitigation measures
                                                                                         impacts
                                                                                         Insignificant,
C1      Ground water, Using impoundment bunds for fuel tankers to
        surface water avoid fuel leakage and spillage to adjacent canal.
                                                                                         Insignificant,
C2      Surface water      Keeping safety in waterway material
                           transportation.
                                                                                         Insignificant,
C3      Surface water           Using freshwater to hydro-test and
                                hydrotesting will be carried out following each
                                phase (reuse and recycle) to save water.
                                In case of using chemicals, non-toxic or low
                                toxic chemicals should be used and will not
                                discharge directly to canal around project
                                zone.
                                                                                         Insignificant,
C4      Surface water      Install mobile toilets at camps during
                           construction, not discharge domestic wastewater
                           directly to adjacent canals.
C5      Surface water      Collecting solid waste completely in construction             None
                           area, absolutely avoid discharging solid waste to
                           canals.


6.1.4     Minimize negative impacts to Economic – Social
Main purporses of mitigating measures on socio-economic impacts are:
- Guarantee security
- Protect laborer/worker health
- Making active and helpful relationship with local population.

No      Object / Aim       Mitigating measure                                               Remain impacts
D1      Local labour Cooperate with the local authority to have a Negligible after
        structure    management plan of employee source in order to construction
                     balance work-force and avoid adverse impacts to phase.
                     the local labour structure.
D2      Community          Keep closely relationship with the local inhabitants             Positive impacts
        relationship       and authority in order to be informed and
                           coordinated to solve problems generated during the
                           project implementation.
D3      Labour force       Comply with the stipulations/regulations of Viet                 Positive impacts
                           Nam Government in hiring the professional and
                           manual labors. Make the convenient condition to
                           enhance skill level for worker to be suitable with the
                           plant development requirements.
D4      Public order       Keep order and security at the project zone                      None
        and security
D5      Labor health       Support safety and health protection equipment to None
                           the labours such as safety helmets, safety-working
                           clothes, ears protective equipment and ensure the
                           sanitary conditional working place.

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No         Object / Aim     Mitigating measure                                              Remain impacts
                            - Develop the Health and Safety Program aiming
                            identification, assessment and inspection of the
                            safety and health risk for the employees in order to
                            have health protection plan during the project
                            implementation.
                            The medical equipment of the plant may also be
                            used for the local people in necessary case.

6.2        MITIGATION MEASURES FOR THE OPERATION PHASE
As mentioned in environmental impact assessment chapter (chapter 4), main adverse
environment impacts in operation phase are air emission, noise, wastewater, solid waste
and incidents. Thus, mitigation measures focus as follows:
     1.    Air pollution treatment
     2.    Noise treatment
     3.    Waste water collection and treatment
     4.    Solid waste collection and treatment
     5.    Prevent incidents

6.2.1 Air pollution treatment
During operation, main fuel used for the turbines is natural gas. In case of temporary
interrupted of gas source, diesel oil will be replaced. The operation of gas turbines will
regularly discharge NOx and CO to the environment through stacks. Mitigation measures for
air emissions from stacks of gas turbines will be applied as follows:

No        Object/ Aim     Mitigation measures                                           Remain impacts
                                                                                        Insignificant,
E1        Exhaust gas     Use the F generation gas turbine with dry
                                                                                        met TCVN
          from turbines   combustion chamber system to reduce NOx
                                                                                        7440:2005
                          emission.
                                                                                        Insignificant,
E2        Exhaust gas     Regular monitor during plant operation to ensure
                                                                                        met TCVN
          from turbines   that turbine operation complying with the design.
                                                                                        7440:2005
                                                                                        Insignificant,
E3        Exhaust gas     Comply strictly the maintenance schedule
                                                                                        met TCVN
          from turbines   according to regulations of manufacturer
                                                                                        7440:2005
                                                                                        Insignificant,
E4        Exhaust gas     Install the main stack of 40m minimum height,
                                                                                        met TCVN
          from turbines   stack diameter is about 6,5 meters so that
                                                                                        7440:2005
                          pollutants in exhaust gas will be dispersed rapidly
                          and ensure that NOX, CO concentration are
                          always lower than TCVN 7440:2005 standard.
                                                                                        Insignificant,
E5        Exhaust gas     Install automatic monitor equipment at the top of
                                                                                        met TCVN
          from turbines   the stacks.
                                                                                        7440:2005
                                                                                        Insignificant,
E6        Exhaust gas     Using high quality fuel with low sulfur (<0.25%) and
                                                                                        met TCVN
          from turbines   create less dust.
                                                                                        7440:2005
          & urgent
          diesel
          generator
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6.2.2 Noise

Noise will significantly generate due to operation of the plant and auxiliary-equipment such
as gas turbine, steam turbine, pumps, compressor, fans, water treatment plant, cooling
water pump, demineralization plant. So, the above equipment needs to be designed
complying with noise standard applied for rural area in the boundary of the plant at every
time:

No      Object/Aim         Mitigation measures                                     Remain impacts

                                                                                   Insignificant,
F1      Noise in plant     Select and install the low noise equipment
                                                                                   met TCVN 3985:1999
        zone               and accessories.
                                                                                   Insignificant,
F2      Noise in plant     Install soundproofed wall or construct
                                                                                   met TCVN 3985:1999
        zone               soundproofed house around the equipment
                           such as gas turbine, steam turbine, air
                           compressor, etc. to reduce noise.
                           Air pipelines of gas turbines, cooling towers,          Insignificant,
F3      Noise in plant
                           safety valves, and diesel engine of fire-               met TCVN 3985:1999
        zone
                           fighting pumps are also soundproofed; and
                           parts of small equipment are sound-proofed
                           in separated hull.
                                                                                   Insignificant,
F4      Noise in plant     Install the noise and vibration sensor system
                                                                                   met TCVN 3985:1999
        zone               at highly noise and highly vibration zone
                           such as air compressor, turbines, etc.
                                                                                   Insignificant,
F5      Noise in plant     Equipment in plant zone and port zone will
                                                                                   met TCVN 3985:1999
        zone               be designed according to industrial standard
                           to ensure that the maximum value of noise
                           is 85 dBA at 1m far from noisy equipment.
                                                                                   Insignificant,
F6      Noise in plant     Making period maintenance plan for
                                                                                   met TCVN 3985:1999
        zone               equipment to minimize noise and vibration.
                                                                                   Insignificant,
F7      Noise in plant     Equip anti-noise equipment for the workers
                                                                                   met TCVN 3985:1999
        zone               working in the plant especially at the high
                           noisy areas.
                                                                                   Insignificant,
F8      Noise to           Establish a green-tree buffer zone between
                                                                                   met TCVN 5949:1998
        residential        the project area and resident area by newly
        zone               planting green-tree corridor around the
                           plant.

6.2.3 Waste water treatment and discharge

During operation phase of the plant, wastewater generated from many sources will be
treated to ensure that it meets the standard before discharging to environment. It may be
classified as follows.
- Cooling water collected from cooling tower.
- Waste water containing oil and lubricant is collected from production zone such as pump
    station, transformer station, DO tanker, and workshop.
- Waste water from sanitary toilet.


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-    Rainy runoff water directly discharge from non-production area of the plant such as
     transportation road, administrative area…

Specific treatment measures for each kind of wastewater will be shown as below:

No      Object/ Aim        Mitigation measures                                        Remain impacts
                                                                                      Insignificant,
G1      Cooling water      Cooling water should take into open gully
                                                                                      met TCVN 5945:1995
        discharge          system to minimize the temperature (<40oC)
                           before discharge to the environment, mitigate
                           heat pollution.
                                                                                      Insignificant,
G2      Cooling water Limit cooling water discharge at stand tide
                                                                                      met TCVN 5945:1995
        discharge     (v=0) to reduce heat pollution.
                                                                                      Insignificant,
G3      Chemicals          Collect to the neutralize tank of wastewater
                                                                                      met TCVN 6984-2001
        contaminated       treatment system. Treat until meeting
        wastewater         Vietnamese standard TCVN 6984-2001 before
                           discharge to Cai Tau river.
                                                                                      Insignificant,
G4      Oily               Collect to oil separator tank and conduct to
                                                                                      met TCVN 6984-2001
        wastewater         neutralize tank of wastewater treatment
                           system. Treat until meeting TCVN 6984-2001
                           before discharge to Cai Tau river.
                                                                                      Insignificant,
G5      Domestic           Collect into the septic tanks and then to the
                                                                                      met TCVN 6984-2001
        wastewater         neutralize tank of wastewater treatment
                           system. Treat until meeting TCVN 6984-2001
                           before discharge to Cai Tau river.

Detail of wastewater collection and treatment system of the whole plant is shown in Figure
6.1. Function of main equipment in share wastewater treatment system of both CM1 & CM2
power plants is summarized as below.

Septic tank
Septic tank is domestic wastewater collection site. Inside of the septic tank, BOD of domestic
wastewater will be decomposed by anaerobic microorganisms.

Oil separate tank
Oil separator tank will separate the oil from water by effect of gravity. It will be designed to
ensure that oil concentration in water equal to or less than 5 ppm according to TCVN
6984:2001.

Neutral tank
Neutral tank is a place that receives effluents treated from septic tank and oil separator tank
as well as cooling tower. Neutral tank is equipped with pH and temperature sensor. NaOH or
H2SO4 solution will be added to adjust pH complying with Vietnam standard. The
temperature of output water from this tank will be adjusted to ensure the maximum variation
is 5oC to compare with the water’s temperature of Cai Tau River. The output water of neutral
tank will meet the Vietnam standard TCVN 6984:2001 and then lead to treated water storage
tank.




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Storage tank for treated water
Function of storage tank for treated water is to maintain a stable discharging output as
discharge treated wastewater to Cai Tau river. Discharging output will be tested by
wastewater dispersion model to mitigate adverse impacts on surface water quality as well as
disturbance impact on sediment of riverbed.


6.2.4 Collection and treatment system for solid waste

Activities in construction and operation phases of Ca Mau power plant will generate solid
waste and hazardous waste that is undesirable and unavoidable secondary products . The
aim of mitigating measures is to limit generating rate of solid waste and to manage
discharging activities. Basing on that, mitigation measures will be proposed as below:


No      Object/ Aim        Mitigation measures                                              Remain impacts
                                                                                            Insignificant,
H1      Solid waste        -    Contract with Ca Mau Water Supply and Urban
                                Facilities Company for collecting and separating
                                solid waste from discharged sources before
                                treating and discharging to the environment.
                           -    Strictly monitor and control wastes collection
                                and treatment

                                                                                            Insignificant,
H2      Non-               Limit or recycle non-hazardous solid waste at
        hazardous          realizable phases to mitigate quantity of solid
        solid waste        waste.

                                                                                            Insignificant,
H3      Collecting of      Contract with Ca Mau Water Supply and Urban
        hazardous          Facilities Company for collecting, transporting,
        solid waste        treating and discharging hazardous solid waste
                           according to Ca Mau DONRE regulations.
                           Setting solid waste containers accompany with
                           guideline board at proper sites to limit scatter of
                           hazardous solid waste in plant zone.
                           Building the temporary landfill in plant to storage
                           hazardous solid waste before transporting for
                           treatment.

                                                                                            Insignificant,
H5      Hazardous          Used chemicals and lubricants will be stored
        waste              separately and suitably before reusing or
                           transporting for treatment.


H6      Other wastes       Other wastes will be collected and discharged to                 Impact in landfill
                           local landfill                                                   only




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6.2.5 Prevent incidents
To ensure safety for all activities of the project, during general design phase of the Ca Mau
power plant, the project owner had contacted and submitted a specific report about design of
fire preventation and fighting system to Agency on Fire Protection and Fire Fighting -
Ministry of Security. Preventing and protection measures will be developed and strictly
implemented to avoid leaking or spillage of chemical and fuel. These measures are applied
as follows:

No       Objects/                                     Mitigation measures
          Aim
I1    Leaking,           Closely controlling liquid product export/import processing to minimize
      spillage           leaking and spillage incidents.
      incident

I2    Leaking,           Install flow meter, overflowing pipes, and safety shutdown valves to
      spillage           prevent overflowing due to supply amount exceeds the maximum
      incident           capacity of equipment.


I3    Leaking,           Equip anti-corrosion layers for collective equipment, storage tanks and
      spillage           wastewater treatment facilities to prevent chemicals in wastewater
      incident           eroded equipment and leaked out.


I4    Fire and           Design and install fuel tanks complying to design standard of API 650,
      explosion          fire preventing and fighting standard agency of US and Vietnamese
      incident           standard:
                         -   Fuel will be stored at temperature below flashing point. Oil
                             temperature will be controlled frequently. Setting cooling water tap
                             at shell and bottom of oil tanks to prevent the increasing of oil
                             temperature. Speed of cooling water spraying               is about
                             30liters/second/meter in perimeter (TCVN 5307-1991). Cooling
                             water will be taken from fire fighting water system.
                         -   Arrange fuel storage tanks separately in safety embankment and
                             they are put on waterproof hard ground to prevent spillage,
                             leaking. Minimize distance between tanks and other
                             equipment/construct is 30 meters (TCVN 2622-1995)
                         -   Equipping oil storage tank that is painted by 3 rust-proof layers and
                             using ventilated-ducts that limit operational pressure of storage
                             tank is not over 0.15 bar.
                         -   Install leaking detector, spillage control equipments and
                             emergency shut-off valves at closing magnetic type to prevent
                             leakage/spillage at fuel storage tank area.
                         -    Install the automatic fire detector and automatic fire fighting
                             equipment system at fuel tank areas and fuel pump station.


I5    Fire and           -   Install the automatic fire detector, automatic fire alarm and auto fire
      explosion              fighting system at gas turbine and generator. When fire occurs,
      incident               system will automatically control and transmit signals to

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No       Objects/                                     Mitigation measures
          Aim
                             emergency stop the turbines, turn off ventilation fans, alarm and
                             start the CO2 fire fighting system to extinguish a fire.


I6    Fire and           -   Checking periodic the pump system, duct pipeline, fuel tanks,
      explosion              chemicals, fuel storage tanks and wastewater tanks in order to
      incident               repair or timely replace damaged pieces of equipment, avoid
                             causing spill incident.


I7    Fire and           -   Establish the network of fire preventing and fighting system with
      explosion              safety exits and staircase at logical place and establish fire-fighting
      incident               system according to technical requirement of industrial factory.


I8    All incidents      -   Establish emergency response plan for each kind of potential
                             incident.
I9    All incidents      -   Equip and supply equipment and system to ensure safety for
                             transportation, using and storing chemicals.
                         -   Working places will be supplied with eye clearer, safety cleaning
                             water taps, individual labour safety equipments such as: mask,
                             safety glasses, gloves, etc.
                         -   All factory members will be frequently exercised for fire preventing
                             and fighting, oil spill response, especially members who working at
                             storage area.



6.3     DECOMMISSIONING PHASE
Adverse environmental impacts from stopping, moving and dismounting equipment of the
plant are also similar to the ones generated from constructing/ installing phases. Thus,
mitigating measures for adverse environmental impacts in this phase are similar as applied
in construction phase. Besides, the plant will apply some specific mitigating measures for
decommissioning phase as follows:

K1.     Establish logical plan for stopping activities and dismounting as well as pay attention
        to interaction with other constructions located in the area;

K2.     Inform decommissioning plan to authorities, related institutions and individuals to
        avoid generating interaction adverse impacts that causes disadvantage for them.

K3.     Dismounting time will be limited at minimum level and suitable dismount technique
        will be used to avoid adverse impacts on adjacent environment and residents.

K4.     Collect and timely classify all dismounted materials to suitable reuse and discharging

K5.     All decommissioning activities will be monitored to avoid incidents causing
        environmental impacts.


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K6.     Set a suitable zone for assembling dismounted materials and choose appropriate
        partners for liquidation equipments in order to quickly clean up the ground.

K7.     Restoring plant area as original status by replanting vegetation cover in order to
        support for land-use purpose of Vietnamese authorities and Project Management
        Board showing at that time.

K8.     Cooperate with local authorities before dismounting in order to provide a specific plan
        that helps the labour forces of the plant aim to minimize potential unemployment
        situation after plant stops its activities.

Decommissioning activities could be carried out after 25 operational years. At that time,
Vietnamese and International environmental policies and laws could be much changed.
Mitigating measures for environments impacts in decommissioning phase mentioned in this
report could be changed to in accordance with future real situation.




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Section       7.
ENVIRONMENTAL
MANAGEMENT PLAN

Environmental management plan for Ca Mau 1 power plant had been mentioned and
approved in detail envieronmental impacts assessment (DEIA) report for Ca Mau power
plant project. In fact, the Ca Mau 2 power plant is enlarged part of the revised project. Thus,
environment management plan should be corrected to enlarge for the Ca Mau 2 power plant.

Environment management plan is established according to Vietnam environmental
standards basing on continuos process: “Planning, implementation, monitoring and
assessment”. Environmental monitoring program has been established from design phase
and carried out throughout project implementation.


7.1     ENVIRONMENTAL MANAGEMENT PLAN FOR THE PROJECT
The project will establish, maintain objectives and devolve tasks for each rank and
department related to environment. Environmental objectives and tasks of the project are
identified based on environment requirement as follows:
    Satisfy environment, safety and health standards established for the project;
    Control and restrict all environment impacts to equal or less than the levels as mentioned
    in EIA report for the project;
    Comply with commitments of environment management proposed by the Project
    Management Board and maintain technical parameters in order to meet environmental,
    safety and health related legal requirements as mentioned in this report;
    Continuously upgrade            safety    and     environment       management         during     project
    implementation.

To implement objectives as above-mentioned, organization and direction for program
implementation is an important factor and include as follows:
    Establish a Safety and Environment Unit and in cooperation with other departments such
    as technical, security departments... to monitor safety and environment matters;
    Provide information related to organization, regulations and necessary guideline for
    implementing environment practices;
    Establish and implement checking, monitoring, review and audit to ensure that
    environment management plan is appropriate;
    Improve and complete environment management system.

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7.1.1 Environment Management Program
Environment management program will include following activities:
   Monitor discharge sources and discharge sites;
   Waste management;
   Establish environment management plan;
   Establish emergency response plan;
   Train staff on safety and environment;
   Monitor, keep result of operations related to safety and environment of the project.

Regularly review and effectively audit environment management plan and correct the plan if
necessary.

7.1.2 Checking and auditing environment management system

Checking and auditing environment management system for Ca Mau 2 power plant as well
as the Ca Mau 1 power plant include:

    Consider environment management system. This checking process will provide following
    issues:
        − Existing environment and identifying potential environmental pollution
        − Introduce technical solutions and advanced technology as well as improve
            environment management and monitoring programs so that they are suitable for
            reality situation.

    Consider environment: periodically inspect on special subjects as follows:
       − Hygiene condition at the project area
       − Wastewater system, wastewater quality
       − Waste management
       − Equipment and measure for accident response

    Auditing environment: auditing environment management and technology issues that
    may be implemented “separately” or in coordination with safety audit.

Results of auditing, assessing, conclusions and recommendations will be documented to
establish a concrete implementation plan and considering, correction and improve factors in
environment management system so that they are suitable for reality situation.

7.2     ENVIRONMENTAL MEASURING AND MONITORING PROGRAM
Main objectives of environment monitoring plan include:
- Identify all environment changes which may cause adverse effects on environment by
   the project implementation;
- Monitor discharge sources (gas emission, waste water and solid waste) and operation of
   environmental protection equipments in order to ensure that these activities will comply
   to legislative requirements;
- Check monitoring process and inspect installation system and equipments in respect of
   pollution prevention and control;
- Prevent potential incidents;
- Propose appropriate environment protection measures based on results of
   environmental monitoring;
- Overcome and repair all weak-points based on results of environment monitoring
   program.
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Environment monitoring for the project is divided into 2 following types:
- Regular monitoring gas emission quality, waste water generated by project operation;
- Periodical monitoring surrounding environment of the project area.
Environment monitoring program will be carried throughout all project implementation
phases, from pre – construction, post – construction and during operation phase.

7.2.1 Monitoring Program for the Discharge Sources

Purpose of regular monitoring discharge source is to ensure that waste sources must be
treated to meet discharge standards before discharging into environment to mitigate
environment impacts generated and have timely measures for preventing and correcting. .
Monitoring program for the discharge sources of the CM2 power plant is similar as the one
for CM1 power plant including regularly monitoring all discharge sources in plant (gas
emission, waste water and solid waste). Monitoring will be implemented regularly by directly
automatic measuring at discharge source or sampling to analyze regularly. Results of
sample measuring and analyzing will be recorded in files to monitor and audit. Refer to
environmental survey and monitoring programs for the thermal power plant projects
promulgated by Agency of Environment - Ministry of Science, Technology & Environment in
1999 [20], monitoring program of discharge sources includes:

-     Monitor strictly collecting and discharging solid waste in construction, operation and
      decommissioning phases of the project;

-     Daily monitor the discharge sources of wastewater, gas emission, checking operation
      process of wastewater treatment system to timely repair if wastewater quality not meet
      the Vietnamese standards ;

-     Monitoring results will be documented to report to higher authorities to have timely
      solvable measures in order to prevent environment impacts.

     Table 7.1      REGULAR MONITORED PARAMETERS IN CA MAU 2 POWER PLANT

     Discharge              Parameter              Frequency                     Sampling site
      source
    Gas emission    Dust, SO2, NOx, CO,            Weekly          3 sampling sites at following location:
                    CO2                                            − 2 sites at two stacks
                                                                   − 1 site at cooling tower
    Noise           Noise, Vibration               Monthly         4 sampling sites at following location:
                                                                   − gas turbine,
                                                                   − steam turbine
                                                                   − gas compressor
                                                                   − Cooling tower
    Cooling         Discharge flow, pH,            Weekly          1 site at discharge point in the plant
    water           temperature, TSS, Cl-                          before flowing to the discharge canal
                                                                   to Cai Tau river
    Industrial      pH, temperature,               Daily           - 1 site at input of wastewater
    wastewater      turbidity, TSS, BOD5,                              treatment system
                    total oil content                              - 1 site at output of wastewater
                                                                       treatment system



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Continuous gas emission monitoring system of gas turbine

Beside above-mentioned monitoring system, project owner has provided a set of continuous
gas emission monitoring system of two gas turbines of CM2 power plant. This is an
automatic system used for monitoring gas emissions from two gas turbines. This system will
monitor CO, CO2 and SO2 content from each gas turbine and continuous monitor O2 and
opaque of discharged gas.

Equipment of continuous air emission monitoring system will be calibrated to ensure that
emission gas limits must be complied with Vietnam standard requirements.

The continuous air emission monitoring system will be placed in air conditioner roof cover,
air samples will be taken from discharged gas pipe of each gas turbine. Sampling pipes will
be provided an electric heater to prevent condensation and absorption discharge gases.
Another function of this system is to keep sample for each channel and is used in the case of
transferring it to take gas samples of other turbine.

7.2.2 Environment monitoring program in the vicinity

Characteristic of the power plant is situated on wetland area, environment diversity and
sensitive including canals, rivers, agriculture soil, residential area and mangrove, so
surrounding environmental monitoring program will be undertaken throughout project
execution to immediately identify environmental pollution source and propose treatment
measures. To identify environment changes, environmental measuring and monitoring
program will be implemented before starting construction works and throughout operating
phase until finishing decommissioning activities.

Environment measuring and monitoring program will be implemented according to each
phase as follows:

1. Pre – construction phase

Environmental measuring and monitoring program will be implemented before starting
plant’s construction, which is considered as environmental baseline study. Environmental
baseline study had carried out as a part of EIA report. Collected data from environmental
baseline study will be used as basic for environment management and next monitoring
activities.

Environmental baseline study for Ca Mau power plant project area had been supplemented
surveyed in period from December 19th to 24th, 2005 by RDCPSE. Analytical results of
Environmental baseline are shown in section 3 of this report. Information and database in
survey program include:

-   Biological environment: terrestrial and aquatic ecosystem;
-   Socio – economic condition in the project area;
-   Sampling and analyzing physio-chemical and biological parameters will identify the
    environment quality of the project area including air, water, soil, and sediment quality.
    Sampling locations are shown in table 7.2.




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    Table 7.2 ENVIRONMENTAL SAMPLING LOCATIONS AT CA MAU POWER PLANT
                             IN DECEMBER, 2005

                                                                                            Co-ordinate
 Sample
               Station                  Sampling location                            Latitude       Longitude
  type
                                                                                     (North)         (South)
                 R1       Cai Tau river – discharge point of
                                                                                    09o14.993'    105o03.555'
                          cooling water CM1
 Surface         R2       Cai Tau river – intake point of cooling
                                                                                    09o14.544'    105o03.938'
  water                   water
                 R3       Ong Doc river – far from downstream
                                                                                    09o13.857'    105o04.512’
                          of Tac Thu sluice of 500m
                 R4       Ong Doc river – far from downstream
                                                                                    09o13.586'    105o04.736'
                          of Tac Thu sluice of 1000m
   Soil          Đ1       In the plant area – bordered on the
                                                                                    09o14.333'    105o03.637'
                          Power plant 1
                Đ2        At surface sluice of Power plant 2                        09o14.262'    105o03.658'
 Ground         G1        Site of drilling well of Lilama Project
                                                                                    09o14.320'    105o03.582'
  water                   Management Board
  Gas            K1       Power plant 2 area                                        09o14.529     105o03.910'
                 K2       Far from south of main stack base of
                                                                                    09o13.963'    105o03.541'
                          Power plant 1 of 1600m
                 K3       Cai Tau residential area                                  09o14.456'    105o04.456'
Note:
-    R1÷ R4:     sampling sites of surface water, sediment, benthos and plankton;
-    Đ1÷Đ2:      soil sampling sites
-    G1:         ground water sampling sites
-    K1 ÷ K3     air sampling sites


2. Construction phase

During construction phase, construction activities must ensure to properly implement
technology requirements and appropriate to mitigation measures of environmental impacts
as mentioned in this report. EPC constructors must take responsibility for dust, noise
monitoring at the project execution area and discharge flow from wastewater treatment
system in order to ensure that pollution parameters are within allowable standards.

After finishing construction and commissioning, the project will carry out one more survey
and sampling in order to identify natural environment changes in construction phase.
Monitoring parameters and frequency are shown in Table 7.3 and 7.4.

Results of environmental monitoring in pre – construction phase and construction phase will
be baseline data for environment monitoring of the next phase.

3. Operation phase

Due to the surrounding area is influenced by combined impacts from project life-time
operation, it is necessary to have period monitoring plan, equipment maintenance plan in
order to immediately detect and prevent potential impacts on economics as well as natural
environment during operation phase of the plant. Result of environmetal monitoring,
equipment system maintenance as well as breakdowns and incidents in operation phase
must be monitored, recorded in files and reported in detail. Monitoring program of ambient
environment of the power plant is undertaken 2 times/year in the dry and rainy season.
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Monitoring program of ambient environment will be enlarged for Ca Mau 2 power plant.
Supplementation sampling location, analytical parameters and monitoring frequency at
surrounding of Ca Mau 2 power plant are shown in table 7.3 and Figure 7.1.
               Table 7.3 PERIOD MONITORING PARAMETERS AND LOCATIONS
                       AT SURROUNDING AREA OF THE POWER PLANT

    Environment                     Parameter                                Sampling site
  Air                      Dust, temperature, humidity,       2 sites, in which:
                           SO2, NOx, CO, CO2                  − 1 site at 1,775m far from CM 2
                                                                  Power plant’s stack’s foot toward
                                                                  South-Southeast
                                                              − 1 site at temporary resettlement area
                             o
  Surface water            T C, pH, TSS, COD, BOD5, 2 sites, in which:
                           DO, Cl-, total N, total P, SO42- − 1 site at discharge point of cooling
                           , total oil, total coliform, heavy     water of the CM 2 power plant to Cai
                           metals.                                Tau river
                                                              − 1 site far from downstream of Ong
                                                                  Doc river of 500 - 1000m
                                                    -
  Ground water             Colour, pH, TSS, Cl ,              1 site, in which:
                           hardness, NO3-, NO2-, SO42-,       − Cai Tau jail area
                           Coliform.
  Sediment                 Hydrocarbon,                       2 sites at surface water sampling
                           Heavy metals                       location
  Biology                  Zooplankton, phytoplankton,                2 sites at surface water sampling
                           benthos                                    location

Besides, in Ca Mau Integrated Gas – Power – Fertilizer (IGPF) area, an automatic
monitoring station for ambient air environment will be equipped.

4. Decommissioning phase
During decommissioning phase, dismantling works must be strictly monitored on-site. After
finishing all dismantling works, an environmental survey program will be carried out in the
surrounding project area to ensure that residual impacts are significant and acceptable.
Sampling locations as well as monitoring parameters in environmental monitoring program in
this phase are the same as periodically monitoring for surrounding environment quality and
are shown in Table 7.4.

        Table 7.4        MONITORING FREQUENCY OF SURROUNDING ENVIRONMENT
                                    OF THE POWER PLANT

              Phase                                                Monitoring Frequency
Pre-construction                         1 time in rainy season and 1 time in dry season for
                                         environmental baseline study
Construction                             1 time after finishing plant construction and installation
Operation                                2 times/year
Decommissioning                          1 time survey
Note: Monitoring frequency may be changed when particularly legal regulations are promulgated in the future.

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Results of environmental measuring and monitoring program will be kept on records and
submitted to competent authorities of environment such as Ministry of Natural Resources
and Environment and Department of Natural Resources and Environment in Ca Mau
province.


7.3     ENVIRONMENTAL MANAGEMENT TRAINNING PROGRAM
Safety and environmental management training program is an important part in environment
management program.

During construction and installation phase, Project Management Board will coordinate with
constructors in order to ensure that project staffs are trained on labor safety and
environment protection.

In operation phase, all staffs of power plant will be trained on environment safety throughout
training courses, operation processes and guidelines, fire fighting exercises and practices,
ect.

Project Management Board will establish and maintain training programs that regularly
updated to help staff at all levels and related functional departments are aware of their
responsibility on environment protection.

Environment training programs will be implemented appropriately for groups selected in the
project and include as follows:
    Environment Management system;
    Environment guidelines and procedures;
    Vietnam Environment law;
    Existing environment problems and detailed environment problems for the project;
    Mitigation measures on organization and technique;
    Environment protection in production;
    Regularly audit and assess environmental protection implementation;
    Periodically training courses on incident response, first aid, fire and explosion, ect.

Beside, project staff will be also trained on special subject. Project Management Board takes
responsibility for ensuring information quality and monitoring overall environment
management function.

7.4     EMERGENCY RESPONSE PLAN
Emergency incident response plan of Ca Mau 1 power plant has been established and
approved to mitigate harms on humans and environment in the project area and its vicinity in
case of incident. This plan will define necessary activities when incident happens, in order to
minimize human, property, equipment and environment damages. This plan must be also
corrected and enlarged for Power plant 2.

Emergency response plan includes:
    Classify and determine all potential incidents due to equipment operation such as fire
    and explosion caused by external cause or pipeline itself and equipment;
    List of internal and external notices;
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    Schema on emergency responsibility organization and information notification sequence;
    Identify role, responsibility of organizations and personals in incident response;
    Necessary equipments for directions and on-site response;
    Periodically training and on emergency response:
    -   Study and practice emergency response exercises, basic first aid, safety and fire-
        explosion courses …
    -   Study on operation, guideline of plant safety and protection regulation for local
        people;
    -   Continuously draw experience from real practice and throughout emergency
        response exercises
    Regularly update new information for emergency response plan.
    Particular implementation steps in case of emergency response:
    -   Isolate whole system or pipeline equipment.
    -   Communicate to emergency direction board, emergency assistance board and other
        response organizations.
    -   First aid and move victims away from incident area.
    -   Response the system from emergency situation.

Beside, prevention and fire fighting plan for the CM2 Power plant is also particularly edited
and approved by related competent organization.

Briefly, during operation, safety objectives in production process will always be paid attention
and so, mitigation measures as above mentioned will be strictly complied to reduce as much
as possible potential risk of the abnormal accidents affected the Plant operation.




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Section        8.                  CONCLUSIONS
The revised project of Ca Mau Power Plant is one of the strategic projects of Vietnam in
order to use most effectively the natural gas from Southwest gas fields and meet the power
shortage demand in the future. The project development will impulse the local economic
development and promote the national industrialization and modernization. It is the strong
motive force to stimulate the development and the change of economic structure in the
province, to improve the province's economics and society and keep the security and politics
at the border of Southwest area .
The Ca Mau 2 power plant has the designed capacity of 750 MW which is undertaken on
the basis of multiplying two times with the Ca Mau 1 power plant's capacity, so it has similar
configuration as CM 1 power plant. The Ca Mau 2 plant will be constructed simultaneously
with the Ca Mau 1 plant on the proposed fertilizer plant's land and is planned to complete in
2008.
Similar to Ca Mau 1 power plant, the construction and installation process of Ca Mau 2
power plant will disturb the soil structure, increase the alum creating ability and soil erosion,
especially at the beginning of rainy season period. The dredge activities to widen port and
the equipment transportation will change the local water current regime and disturb the
water environment. It makes increasing the suspended solid and pollutants content in river-
bed (mud) at the area near Cai Tau confluence. The impact level is assessed as medium
during the construction process.
In the operational phase, the content of pollutants in emission gas at the two main stacks of
the plant in both cases using natural gas and diesel is lower than the emission gas
standards TCVN 7440:2005 applied for thermo-electric industry. In the field of gas emission
in both cases of the two power plants (Ca Mau 1&2) using total natural gas and using total
(100%) diesel with maximum sulphuric content of 0.5% weight, the maximum hourly and
daily content on ground of the emission gas (NOx,CO,SOx) is lower many times than the
Ambient Air Standards of Vietnam TCVN 5937:1995. It shows that the emission gas of Ca
Mau 2 power plant in both cases using natural gas and diesel affects the local ambient air
environment insignficantly.
The continuous intake of supplementary cooling water with the volume of 2 m3/s from Cai
Tau river and the frequent discharge of cooling water or treated industrial wastewater into
Cai Tau river will change the local current of this river system. In dry season (November to
April), when Tac Thu sluice is opened, the continuos intake of cooling water for both power
plants (1&2) will increase the water volume from Cai Tau river toward Ong Doc river, and
increase the current velocity, but not affect the volume of irrigational water for local
agriculture.
When the Tac Thu sluice is closed, the maximum current upstream and downstream of Cai
Tau river is decreased much in comparison with the one in the case of opening Tac Thu
sluice. The continuos intake of 2 m3/s cooling water for both power plants (1&2) makes the
water level of Cai Tau river decrease from 1 to 6 cm. At cooling water intake site, the flow
decreases about 2.3 to 2.7 m3/s. At cooling water discharge site of two power plants (1&2),
the flow decreases about 4.3 - 4.7 m3/s.

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The continuos cooling water discharge of Ca Mau 2 power plant into Cai Tau river (option 2)
will be more optimal than the discharge into Cai Tau confluence (option 1). In the normal
operation condition, with the temperature of cooling water discharge of 35oC, the continuos
cooling water discharge of two power plants will only slightly increase (average one of 1.1oC
and highest one of 3.5oC at calm tide) temperature of the river. This will impact insignificantly
on water quality of Cai Tau river and Ong Doc river. In case of tail gas incident, with the
cooling water discharge temperature of 40oC, cooling water discharge of two power plants
will cause increasing the temperature significantly for section of Cai Tau river from cooling
water discharge site from the CM 1 power plant to Cai Tau confluence (average increase
temperature of 2.3oC and highest one of 9oC at calm tide). However, Cai Tau river section is
affected by East and West sea tide, so the high temperature increase only lasts from 30
minutes to 1 hour a day.

Because the treated industrial wastewater volume of two power plants (1&2) is very small,
the discharge of the treated industrial wastewater volume of the two power plants (1&2)
insignificantly affects the Cai Tau and Ong Doc rivers' water quality.

In order to conduct environmental protection better, the project will develop environmental
management plan combined with environmental monitoring plan. The environmental
management plan will control and implement the mitigation measures, simultaneously guide
employees to obey strictly the environmental standards in order to ensure all of the
pollutants created in operational period will be strictly controlled within allowable limit.

Recognize the importance of environmental protection, the project owner commits that they
will strictly obey the Vietnamese standards, the advanced technical solutions, the mitigation
measures for environmental pollution and the suitable environmental management plans as
mentioned in this report including:
1. Emission gas SOx, NOx and dust at the discharge sites meet TCVN 7440:2005, other
   emissions will comply Vietnam current environmental standard;
2. Pollutant content of the ambient air quality will meet the Vietnam current environmental
   standard;
3. Temperature of cooling water discharge will comply the Vietnam current environmental
   standard (<40oC)
4. Treated industrial wastewater will comply the Vietnam current environmental standard

In the project implementation period, the project owner always anticipates a part of budget
for environmental protection including:
1. In the construction, installation and commissioning phases: the expenditure for
   environmental protection (including construction and installation of wastewater treatment
   system; waste collection and treatment, etc.) is in the EPC package of the power plant.
   Whole of the treatment system will be completed at the plant’s commissioning phase.
2. In operational phase: the expenditure for environmental protection will be in the plant's
   operational fund.

Furthermore, the project owner will closely coordinate with the state organizations and
the local authorities to implement the project safely and to get the high economic and social
effect. The project owner commits to strictly implement the measures mentioned in the EIA
report in order to implement the project safely, effectively; less affect the environment and
will be legally responsible if the project breaks the Vietnamese environmental regulations
and standards and if the environmental pollution accident occurs.


CPMB– RDCPSE-Final report                                                                       June, 2006
                       APPENDIX 1

 APPROVAL DECISION OF ENVIRONMENTAL
     IMPACT ASSESSMENT REPORT

1. Approval Decision No.460/QĐ-BTNMT of MONRE on April
   23, 2004 for DEIA report of Ca Mau power plant.

2. Approval Decision No.297/QĐ-BTNMT of MONRE on March
   23, 2006 on approval of supplemental EIA report for Ca Mau
   power plant.
                   APPENDIX 2

BASIC THEORY AND RESULTS OF AIR
        EMISSION MODEL

1. CA MAU 2 COMBINED CYCLE POWER PLANT – USING 100%
   NATURAL GAS FUEL

2. CA MAU 2 COMBINED CYCLE POWER PLANT – USING 100%
   DIESEL OIL FUEL

3. CA MAU 1&2 COMBINED CYCLE POWER PLANTS – USING 100%
   NATURAL GAS FUEL

4. CA MAU 1&2 COMBINED CYCLE POWER PLANTS – USING 100%
   DIESEL OIL FUEL
          APPENDIX 3

 BASIC THEORY AND RESULTS OF
COOLING WATER DILUTION MODEL
                EMISSION GASES DISPERSION MODELING
To determine the dispersion of emission gases from stacks in the Ca Mau power
plant, a refined dispersion modeling program ISC- ST3 (The Industrial Source
Complex Short-Term) have been used. This model was developed by the US
Environment Protection Agency and is used to predict pollutant concentrations from
continuous point, flare, area, line, volume and open pit sources. The ISC dispersion
model combines various dispersion modelling algorithms to assess the air quality
impact of emissions. The basis of the model is the straight – line, steady state
Gaussian plume equation.

The concentration of one site far from stack a distance x, from central line of plume
horizontally a distance y, from ground a distance z; is calculated by basic equation:


                 Q             - y2             - (z – H)2             - (z+H)2
  C(x,y,z) =             exp          exp                     + exp
               2πσyσzu         2σy2                 2σz2                    2σz2

Where:
     C(x,y,z):       Concentration at co-ordinate of (x,y,z), (g/m3)
     u :             Wind velocity at the top of stack (m/s)
     Q:              Loading of polluted substances (g/s)
     H:              Stack height (m)
     σy ,σz :        Vertical and horizontal deviation of gas plume (m)

Neccessary input data for the emission dispersion model running are as follows:

             Neccessary data                                    Unit
 Type of emission source                                     Point; Area
 Number of emission source                                       1..n
 Stack height                                                     m
 Stack diameter                                                   m
 Stack position                                                (x,y) m
                                                             o
 Exit gas temperature                                         C or Kelvin
 Gas exit velocity                                               m/s
 Elevation of emission area in                                    m
 comparison with general foundation
 Pollutants (gas / particulate)                        NOx, COx, SOx; dust....
 Pollutant rate                                                g/s
 Pollutant's concentration                               mg/Ncm (mg/m3)
 Length of emission area                                        m
 Hourly meteorological data :
 - Year; month; day; hour                             (1997; 1..12; 1..31; 1..24)
 - Wind direction                                              0..360o
 - Wind speed                                                    m/s
                                                                  o
 - Ambient temperature                                             C
 - Atmosphere stability                                          A..G
 Type of emission area                                      Urban, rural
 Emission flowrate of each source                              kg/ min.




                                            i
ISCST3 requires hourly meteorological data records to define the plume rise,
transport, diffusion and deposition conditions in a given area. The model estimates
the concentration or deposition value for each source and receptor combination for
each hour of input meteorology, and calculates selected short – term or the entire
period of input meteorology averages.

To calculate the distance (meter) from a stack to an impacted areas, the UTM
Coordinate System is used. For example, the coordinate of a stack at (7 43400m E,
11 56600m N) is briefly written (43400, 56600).




                                         ii
         CALCULATION METHOD FOR DISPERSION
     OF ORGANIC POLLUTION IN RIVER/CANAL SYSTEM
Present, domestic wastewater occupies up to 90% of total wastewater volume
causing water source pollution, of which mainly are organic wastes. In self- cleaning
process, organic wastes are mainly biochemical decomposed and dilluted by current.
Required oxygen volume for microorganisms to decompose organic wastes in one
volume unit of wastewater sample is called Biochemical Oxygen Demand and
counted by mg of oxygen per litre. Natural water has dissolved a certain oxygen
volume called Dissolved Oxygen. Oxygen content in water changes by many
reasons as follows:
-   Oxygen dissolution from the air into the water.
-   Oxygen generation in the water caused by photosynthesis of phytoplankton
-   Oxygen loss for oxidation to decompose organic compounds in the water and
    sediments in the bottom.
-   Part of oxygen is neccessary for plankton respiration.

Imitating DO, BOD changes in the water is great part of water quality researching
projects. On the one hand, DO is general parameter for life in water environment and
almost wastes interact with oxygen. On other hand, BOD is main reason for DO
content reduce in the water. Therefore, BOD imatating model always associates with
DO.

In recent years, due to quick development of Personal Computer and perfection of
digital methods, mathematic model for water quality imitating proves as a strong,
rapid and economic tool for designers and managers, especially in water resource
sector.

    Basic equations and solved algorithms

When examining water quality problems in river/ canal system, one-way model is
often used and hydraulic components (field of velocity) are drawn from measuring or
from hydraulic model through solving following set of Saint-Venant one-way
equations:
                                          ∂Z       ∂Q
                                       W       +          = q          (1)
                                          ∂t        ∂x
                ∂Q       ∂ ⎛ Q2 ⎞      ∂Z       gQQ
                    +      ⎜ ⎟ + gA          +           = 0           (2)
                ∂t      ∂x ⎜ A ⎟
                           ⎝ ⎠         ∂x       ARC 2

where :      W - width of water surface; A - area of horizontal tangent surface; Z -
water level in comparison with standard altitude; Q - flowrate through horizontal
section; g - gravitation acceleration; C - resistance coefficient; R - hydraulic
radius; q - entering flowrate such as pump, discharge; t - time ; x - coordinate along
the river.

After solving (1)-(2) by digital method with appropriate begining and edge conditions,
water level Z, flowrate Q and field of velocity are found.



                                           iii
BOD and DO changes in the river/ canal are described by following one-way
dispersion equation:

a) For BOD with concentration B :

∂B       Q ∂B         ∂2B         q                             q
     +          = E           −     B − ( K1     + K 3 ).B +      Bq    (3)
∂t       A ∂x         ∂x 2        A                             A

b) For DO with concentration D :

∂D       Q ∂D          ∂2D q                              q
     +           = E        − D + ( Ds − D) K 2 − K 1 .B + Dq           (4)
∂t       A ∂x          ∂x 2
                             A                            A

where : Bq, Dq are BOD and DO contents in entering flow. Ds is oxygen saturation.
K1 is constant for BOD change. K2 là gas penetration constant. K3 is constant for
BOD change by sedimentation. U=Q/A is average current speed. E is dispersion
coefficient. Generally Ds is a function of temperature.

Gas penetration constant K2 usually is function of current speed and depth. One of
the practical formulars for K2 is Bennett and Rathbun formular as follows:
                                          U 0.674
                           K2 = 2.33 ⎯⎯⎯⎯
                                          h 1.865
where : U - average current speed ( m/s) ; h - average depth (m) ; K2 measured
by unit/day.

Wrigh and McDonnel [1] have recomended following formular for K1:

                             K1 = 99.3 Q -0.49      ( 1/day )

both K1 and K2 are functions of temperature. Q (m3/h) is flowrate.

To examine self- cleaning ability of each river, self- cleaning constant f is advanced
and defined by following formular:     f = K2 / K1. It is noted that although K2 and K1
depend on temperature, their ratio, f, almost not depends on temperature.

Equations (3)-(4) have the same form:
             ∂S         ∂S       ∂2S
                   + U      = E 2 − aS              + b           (5)
              ∂t        ∂x       ∂x

where a > 0 and b is known constant; S is BOD or DO contents. Equation (5) is
solved digitally by decomposition method, of which the loading equation is solved
purely in first time step:

                    ∂S           ∂S
                         + U         = − aS + b                 ( 6)
                    ∂t           ∂x
 but along the set of specific lines dx/dt = U, its root is:
                S = ( S 0 − ) exp(− at ) +
                              b             b
                              a             a
where S0 is concentration at the specific line root.

                                            iv
Following is to solve diffusion equation:
                       ∂S          ∂2S
                               = E 2
                       ∂t          ∂x

After the solving process, we have root of (5) equation within one time step. This
process is repeated for next step.

    Calculation program for BOD and DO contents in complicated river/ canal
    system WQ

Based on the above mentioned algorithms, a computer program has been
developed named WQ (Water Quality). Calculated results are as follows:
-   Water level, flowrate, speed, BOD and DO contents at all concerned points in the
    river system.
-   Maximum, minimum and average values of the above mentioned parameters.
-   Self- cleaning constant at concerned points.
-   It is available to imitate complicated system with water storaging areas, water
    supplying and using projects, tidal affected river/ canal systems.

Reference
1. WHO, Assessment of sources of Air, Water, and Land Pollution, Part II. Geneva,
   1993.




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