SECTION 3_17_ PREVENTING LEGIONNAIRES DISEASE by hjkuiw354

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									      SECTION 3(17)





PREVENTING LEGIONNAIRES

        DISEASE

Section 3(17): Preventing Legionnaires Disease


                                          PREAMBLE

In order to comply with the Council’s Health, Safety and Welfare Policy and statutory
obligations, the guidance in this section sets down the steps, which must be taken for the
prevention of Legionnaires Disease.

It is very important that all managers who have a responsibility for "at risk" premises understand
what is required and take appropriate action. If there is any doubt about the meaning or
application of this guidance, or further information or training is needed, please contact the
Environmental Health Section in the Public and Environmental Services Department.




                                          CONTENTS

                                                                                        Page No

Policy requirement                                                                        1

Introduction                                                                              1

Design and construction at systems                                                        2

Operation and maintenance procedures                                                      6

Inspection, testing and sampling procedures                                               7

Personnel                                                                                 10

Record Keeping                                                                            11

References                                                                                12

Appendix

Water Services Register*                                                                  13


*Originals of checklists and other documents suitable for photocopying and use or distribution
are given in Section 5


(Total numbered pages in this section: 16)




Health, Safety and Welfare Manual                November 2003
Section 3(17): Preventing Legionnaires Disease

PREVENTING LEGIONNAIRES DISEASE

Policy requirement
The Council’s Health, Safety and Welfare Policy necessitates that managers take all reasonable
steps to minimise the risk of Legionellosis occurring as a result of the operation of premises
under the Council’s control.

Introduction
Legionnaires disease is a pneumonia that principally affects those who are susceptible due to
age, illness, immunosuppression, smoking etc., and may be fatal. It is commonly caused by the
bacteria Legionella pneumophila.

This and other related bacteria can cause a number of other less serious illnesses which are not
fatal or permanently debilitating but which can affect all people. The term legionellosis is used
to describe all of these infections. The legionellae bacteria are widely distributed in nature and
are commonly found in surface water and wet soil. However, they can only cause infection if
inhaled in a contaminated aerosol (fine water droplets). Whilst these bacteria are not normally
found in mains water, given the right conditions they can become established within the water
systems of buildings.

Once present in the water system infection can result if contaminated aerosols are created
which can then be inhaled either by the occupants of the building or persons in the close vicinity
of the building. Aerosols are released from certain types of water cooling plant (usually
associated with air conditioning systems), spa pools, showers, spray taps etc. Most outbreaks
have been associated with water cooling plant, a few with spa pools and some with showers.

Whilst plumbing systems within buildings are relatively sate it is prudent for rules of good
practice to be applied to these installations.

This guidance is concerned with the normal piped systems, including showers etc., within
buildings and is intended to achieve high standards of hygiene and to minimise the risk to public
health. The aim of this document is to provide practical guidance for:

(a)	   minimising the risk of water systems becoming contaminated; and

(b)	   ensuring that conditions favourable to colonisation of water systems are eliminated so far
       as possible.

DESIGN AND CONSTRUCTION

General

A Water Services Register must be maintained at each site. The Water Services Register must
contain:

(a)	   a schematic diagram of all water services updated to show any alteration or modification
       subsequently carried out. This should be produced and attached on site.

(b)	   a record of monthly inspections including full details of the corrective action including
       cleaning and disinfection procedures completed.

(c)	   a copy of annual inspection records.

(d)	   a description of any maintenance, repairs and alterations carded out. Information to be
       produced and attached on site.


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Section 3(17): Preventing Legionnaires Disease

(e)	   a copy of the results of any water samples taken.

New systems shall be designed and constructed in accordance with BS6700 and the current
edition of the Model Water Bylaws.

All new systems shall be thoroughly cleaned and disinfected in accordance with BS 6700. Such
procedure to be completed not more than 7 days prior to occupation of building.

Only materials and fittings specified in the current edition of the Water Research Council's
'Water Fittings and Materials Directory' may be used when carrying out works of repair,
replacement or alteration to existing systems.

Before re-entering service those parts of any system to which repairs, replacement or alterations
have been carried out must be thoroughly cleansed and disinfected in accordance with BS
6700.

All storage tanks must be clearly labelled to indicate the system served.

Hot and cold services must be clearly identified by means of permanent labels at suitable and
sufficient locations.

Before installing aerosol producing fittings (e.g. showers, hose type showers operated via taps
etc.) a careful assessment of the actual need must be carried out. Complex systems should
only be installed where:

(a)	   showers are essential; and

(b)	   showers will be used regularly (i.e. daily)

If they are desirable rather than essential and the usage is less than weekly, alternative facilities
should be considered, e.g. baths or an instantaneous type of unit.

Storage Tanks

(a)	   All storage tanks must be provided with tight fitting and removable lid(s) or fixed covers
       with removable access hatches.

(b)	   Any overflows/vents should be protected by insect/bird proof screens.

(c)	   The tanks shall be provided with insulation to all exposed surfaces.

(d)	   Multiple storage tanks serving one system must be connected in series, so as to ensure
       the maximum through flow and elimination of static areas.

(e)	   Storage tanks must be located in an enclosed room (or area) proofed against the entry
       of birds and vermin, and so protected, and constructed as to minimise the effect of solar
       heat gain on the tanks.

The storage tank shall be so sited that adequate access is provided to all pipework, valves, and
top to enable works of inspection, maintenance and repair to be carried out effectively and
efficiently.

Pipework

(a)	   All pipework shall be insulated in accordance with BS 6700.


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(b)	     Suitable and sufficient drain points shall be provided to ensure that all parts of the
         system can be drained down.

(c)	     All deadlegs on new live hot water systems should not exceed 450mm. All redundant
         pipework and fittings on both hot and cold systems shall be cut back and removed to a
         point not exceeding 150mm from its point of source.

NOTE: 150mm is impractical in some situations due to physical restrictions/ access.	 300mm will
      be accepted in these situations.

(d)	     Hot and cold service pipes should be spatially separate whenever possible and when run
         horizontally hot should be located above cold pipes.

(e)	     Cold pipes should be routed clear of heat sources and/or given additional
         shielding/lagging to prevent temperature gain.

Calorifiers
                                                                                                 o
(a)	     To allow for pasteurisation, each calorifier shall be capable of being heated to 70 C and
         of maintaining this temperature for a minimum period of three hours.

(b)	     A pumped return circuit shall be provided to each calorifier and connected into the lowest
         point of the calorifier to help prevent temperature stratification. The pump shall be sized
                                                          o
         to ensure that a return water temperature of 50 C is maintained.

(c)	     Temperature gauges shall be fitted to indicate the temperature of both flow and return
         water.

(d)	     If two of more Calorifiers are required for duty or standby they shall be connected and
         run in series. Each calorifier shall be maintained at 60oC or above.

(e)	     If at any time one or more Calorifiers are taken out of service, those Calorifiers should be
         isolated, drained and ventilated to atmosphere by removal of one or more inspection or
         access covers.

(f)	     A drain down point (minimum size 20mm) shall be located at the lowest point on each
         calorifier.

(g)	     Each calorifier shall be provided with suitable removable inspection and access covers to
         allow scale and rust to be removed.

Showers and Mixing Valves

  (a)	   All mixing valves are to be thermostatically operated and of the fall safe type.

 (b)	    All mixing valves to be complete with the following fittings on both hot and cold water
         service connections:

         Isolating Valves - lockshield pattern in schools, and if in exposed positions in public
         areas;

         Strainers; and

         Non-return Check Valves - (most mixing valves are provided with built in non-return
         valves as standard).


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(c)	   All mixing valves serving showers shall be provided with an automatic drain valve fitted
       directly to the bottom outlet connection of the mixing valve.

       If the mixing valve is serving a shower outlet fitted with a push button timer, the push
       button must be fixed directly to the mixing valves top outlet and the automatic drain valve
       fitted directly above the push buttons on the service pipe.

(d)	   AlI service pipes from the mixing valves to the shower outlets shall rise vertically and
       only drop below this position where feeding the shower outlet.

(e)	   When a push button is required the mixing valve shall serve ONE shower unit head only.

(f)	   All service pipes from mixing valves to outlet positions (shower nozzles or taps) to be run
       NO MORE than 2.0m in any one direction.

(g)	   AlI shower outlets to be of the nozzle type and be able to be fully disassembled for
       cleaning.

OPERATION AND MAINTENANCE

Operation

Cold water must be stored and distributed at temperatures of less than 20 degrees
Centigrade.

Water stored in the calorifier must be 60 degrees Centigrade or greater throughout the
calorifier.

Water returned to the calorifier must be 50 degrees Centigrade or greater.

The temperature of hot water (undiluted) at the outlets must be 50 degrees Centigrade or
greater within one minute of running.

At temperatures above 50 degrees Centigrade the danger of scalding increases.

Where these temperatures cannot be maintained then thermal disinfection must be completed
weekly by the responsible person.

If a system, or part thereof is not to be used for more than seven days it should be isolated and
drained down if possible, or subjected to thermal disinfection (see below).

Before carrying out thermal disinfection the temperature of the calorifier contents must be
raised, sufficient to achieve a temperature of 60 degrees Centigrade at each outlet. The water
must then be circulated throughout the system or part thereof which is to be disinfected. Each
tap and appliance must be run sequentially for five minutes at full temperature (i.e. not less than
60 degrees Centigrade). The temperature of the water must be monitored.

Maintenance

Only materials and fittings listed in the current edition of the Water Research Council 'Materials
and Fittings Directory' should be used for repairs renewals and alterations.

All lagging must be replaced and secured in position.




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Section 3(17): Preventing Legionnaires Disease


Dismantle, de-scale and thoroughly clean all shower head fittings at suitable intervals to prevent

the build up of visible scale.


Pipework and fittings etc. must be effectively cleansed and disinfected in accordance with BS

6700 before being taken into use.


All leaks must be stopped as soon as possible.

Replace and secure in position all storage tank covers.

INSPECTION, TESTING AND SAMPLING PROCEDURES

General

To ensure the effective implementation of this guidance a documented system of inspection and
testing is required. Sampling however should not be undertaken as a matter of routine. It is to
be used only to verify the effectiveness of the other procedures and to assist in the investigation
of suspected disease.

A system of monthly and annual inspection and testing is required as detailed below. Details of
the monthly checks and annual survey should be recorded in the Water Services Register. The
Survey Form (L3) should be used for the annual inspection and copies passed to:

•     Appropriate Director
•     Director of Environment

INSPECTION AND TESTING PROCEDURES

Monthly
                                                                                        o
1.	      Check that the calorifier thermostat indicates temperature of not less than 60 C.

2.       Check that temperature of return water to calorifier is not less than 50oC.

Note: Temperatures should be checked in the morning before water is drawn from the system.

3.	      Check that all showerheads are clean and free from visible scaling.

4.	      Check that the hot water at the outlets closest to, and furthest from, the calorifier
         reaches 50oC after running for one minute.

5.	      Check that the cold water at the outlets closest to, and furthest from, the calorifier does
         not exceed 20oC after running for one minute. Where fail safe thermostatic valves are
                                                     o
         fitted it will not be possible to achieve 50 C at the outlet. A surface temperature probe
         should be used to ascertain the temperature of the water in the hot water supply pipe
         immediately before the valve.

Annually

1.	      Ensure that the tank room is free from infestation by birds with no evidence of feathers
         or nesting material. If found locate and proof entry points and clean area to remove all
         such remains.

2.	      Ensure that storage tanks are labelled, to indicate the system (s) supplied.


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Section 3(17): Preventing Legionnaires Disease


3.	    Ensure that tank covers are in good repair, free from defects, close fitting and correctly
       and securely positioned.

4.	    Visually inspect the inside of the storage tanks and ensure that they are free from dirt,
       dust, debris, algae, rust and other foreign bodies.

5.	    Ensure that lagging material to tank and pipework is of the correct type and thickness, is
       complete and correctly positioned.

6.	    Ensure that drain valves are flushed through to remove loose scale rust etc.

7.	    Check that hot water at all outlets reaches 50oC after running for one minute. Where fail
                                                                                o
       safe thermostatic valves are fitted it will not be possible to achieve 50 C at the outlet. A
       surface temperature probe should therefore be used to ascertain the temperature of the
       water in the hot water supply pipe immediately before the valve.

8.	    Check that cold water does not exceed 20oC at all outlets.

9.	    Ensure that all redundant fittings and pipework have been removed. Where a deadleg
       remains it should not exceed 150mm.

10.	   Isolate and drain each calorifier. Remove all inspection and access covers and remove
       ALL scale and rust from within the calorifier. If manual removal of scale is unsuccessful
       chemical cleaning should be used. This work should be carried out by a specialist in that
       field to ensure correct and safe procedures are followed. On completion the calorifier
       shall be thoroughly flushed through and should be thermally disinfected prior to being put
       back into operation.

11.	   Ensure that the Water Services Register is updated regularly.

12.	   Instigate any remedial action identified by the annual inspection.

13.	   Enter a copy of the completed Annual Water System Survey Form in the Water Services
       Register and send copies to appropriate Director and the Director of Environment.

14.	   All thermostatically controlled mixing valves shall be serviced descaled and disinfected.

Water Sampling

This should only be undertaken by staff of the Environmental Health Section, or specialist
consultants.

The interpretation of bacteriological results is difficult and is likely to vary according to the
laboratory undertaking the bacteriological examination. Therefore the following scheme should
be used to interpret results and determine an appropriate response.




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Section 3(17): Preventing Legionnaires Disease

No. of Legionella

       Level             Bacteria                                    Action

 1. Low               <102 c.f.u/ml         Review operation and maintenance procedures.
                                            Pasteurise or disinfect system.

 2. Medium           102 - 104 c.f.u/ml     Immediate closure of all aerosols (e.g. showers)
                                            served by same system. Then as 1 above

 3. High              > 104 c.f.u/ml        Complete close down of system and immediate
                                            investigation by the Environmental Health Section.

PERSONNEL

Appointed Persons

Personnel must be appointed at each location to which this guidance applies:

(a)	      to act as ‘responsible manager’ and supervise the implementation of this guidance; and

(b)	      to be responsible for the day to day operation, maintenance and inspection of the
          system.

These personnel will be identified in the organisation and arrangements section of the safety
policy document. This should include arrangements for staff absence due to leave, sickness
etc.

Training

Appointed personnel should know and understand:

(1)	      the potential sources of infection and the risks they present;

(2)	      the requirements of this guidance, and the significance of the various requirements; and

(3)	      the methods to be used to implement this guidance including the procedures for
          inspections and testing.

RECORD KEEPING

Water Services Register

The Responsible Manager must ensure that the Water Services Register is updated monthly.
Where adverse observations are recorded and corrective action is required the responsible
manager must ensure:

1.	       That timely corrective action is completed and recorded in the Water Services Register.

2.	       Where it is not possible to complete the corrective action within a reasonable period the
          appropriate system or part thereof is taken out of service. This should include the
          isolation and draining of the affected part.

3.	       Before taking a system or part thereof back into service after closure that the appropriate
          disinfection procedure has been satisfactorily completed.

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Section 3(17): Preventing Legionnaires Disease


Retention of Records

Records required to be kept as part of the Water Services Register must be updated regularly
and all records must then be retained, available for inspection at the location of the water
system for a period of not less than two years.

REFERENCES

1.	    The control of legionella in Health Care Premises (HMSO).

2.	    TWS Guidance Notes on Maintenance of Plumbing Systems.

3.	    TWS Water Quality Survey Sampling Protocol.

4.	    TWS Disinfection of an installation.

5.	    Technical Memorandum TMB, "Minimising the risk of Legionnaires Disease" - Chartered
       Institute of Building Services Engineers.

6.	    BRE Information Paper.

7.	    The Control of Legionellosis including Legionnaires Disease. HS(G)70 (HMSO).

8.	    The prevention or control of Legionellosis (including Legionnaires Disease) - Approved
       Code of Practice (HMSO).

9.	    Water Fittings and Materials Directory - Water Research Council.

10.	   BS 6700 "Specification for design, installation, testing and maintenance of services
       supplying water for domestic use within buildings and their curtilages" - British Standards
       Institute.

11.	   Model Water Bylaws.

12.	   L8 Legionnaires Disease – The Control of Legionella Bacteria in Water Systems – ACOP
       and Guidance.

13.	   IND(G)253L - Controlling Legionella in Nursing and Residential Care Homes.




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Section 3(17): Preventing Legionnaires Disease

                                                                                                                                  APPENDIX 1


                                                  WATER SERVICES REGISTER

                                                                         for

.....................................................................................................................................................

.....................................................................................................................................................

.....................................................................................................................................................

(Insert name and full address of premises)




                                                        Responsible Manager:

.....................................................................................................................................................


.....................................................................................................................................................


.....................................................................................................................................................


(Insert name and title of person responsible for overall health and safety within the premises)




Date: ...................................





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Section 3(17): Preventing Legionnaires Disease


                          INDEX TO WATER SERVICES REGISTER

1.0    Schematic diagram of water services. To be produced and attached on site.


2.0    Record of monthly Inspections - Form (L1).


3.0    Record of corrective action - Form (L2).


4.0    Record of annual inspection survey - Form (L3).


5.0    Summary of annual inspection survey - Form (L4).


6.0    Details of any maintenance, repairs and alterations - Form (L5).


7.0    Results of any water sampling. To be attached on site.



Note: All records must be kept for a period of not less than two years.




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Section 3(17): Preventing Legionnaires Disease


                                           MONTHLY INSPECTION RECORD (L1)



Premises: ....................................................................................................................................


.....................................................................................................................................................





Date of inspection: ................................


                                                                        Recorded
   Item                          Check                                 Temperature                                      Target

      1          Calorifier                                                                             Not LESS than 60oC

      2          Return water                                                                           Not LESS than 50oC

      3          Hot water

                 (a) *nearest outlet                                                                    Not LESS than 50oC

                 (b) *furthest outlet                                                                   Not LESS than 5 0oC

      4          Cold water

                 *nearest outlet                                                                        Not MORE than 20oC

                 *furthest outlet                                                                       Not MORE than 20oC

      5          Are showerheads clean                                                                  Clean and free from visible
                 and free from visible                                                                  scale.
                 scale?


Signed: ..................................................              Date: ..........................



NB	        If the recorded temperature does not agree with the target, or if the showerheads are
           scaled, corrective action is required.

           Details of the corrective action together with the steps to verify the effectiveness of those
           actions must be recorded on the corrective action Form (L2). Upon completion of the
           corrective action the item must be re-inspected and the results recorded and certified as
           correct.




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Section 3(17): Preventing Legionnaires Disease




                                                      CORRECTIVE ACTION FORM (L2)


                                                                                    Premises: ...................................................................



                                                                          Date              Result of
     No.          Details of action required (inclusive of timetable)   completed         re-inspection




                                                                               Date of monthly or annual inspection:................................





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Section 3(17): Preventing Legionnaires Disease




                       ANNUAL WATER SYSTEM SURVEY FORM (L3)


No.                  Question                      Yes / No   Action required if answer is No

1     Is the tank room free from infestation                  Locate and proof the entry points.
      by birds and from feathers and nesting                  Clean tank room and remove all
      material?                                               such evidence of infestation.
2     Are storage tanks identified by labels?                 Identify tanks and label.
3     Are tanks lids / covers in good order                   Repair or replace within one
      and free from defects?                                  week.
4     Are tank lids / covers secured in the                   Immediately secure in position.
      correct position?                                       Ascertain the cause and report to
                                                              the appropriate manager and
                                                              take steps to ensure this is not
                                                              repeated.
5     Is the inside of the tank visually free                 Implement cleaning and
      from accumulation of dirt, debris, dust,                disinfection procedure as per the
      algae, rust and foreign bodies?                         Code of Practice.
6     Is lagging of tanks and pipework in god                 Re-secure loose material.
      condition, complete and securely
                                                              Replace missing and defective
      positioned?
                                                              lagging.
                                                              If missing or damaged ascertain
                                                              and record reason.
7     Have drain down valves been flushed                     Immediately arrange to flush
      through with clean water?                               through.
8     At al outlets, test hot water temperature               Ascertain cause. See Code of
      after allowing water to run to waste for                Practice.
      1 minute. Does the hot water reach
         o
      50 C?
9     At all outlets, test the cold water                     Ascertain cause. See Code of
      temperature after allowing water to run                 Practice.
      to waste for 1 minute. Does the cold
                                o
      water remain below 20 C?
10    Have all fittings and pipework been                     Identify fittings and pipework for
      removed to leave deadlegs for not                       removal.
      more 150mm in length?
11    Has rust scale etc. been flushed out of                 Implement descaling as
      the calorifier(s), and the calorifier                   recommended by the guidance.
      thermally disinfected?
12    Has the Water Service Register been                     Detail omissions and update the
      kept up to date?                                        record.
13    Have all shower mixer valves and                        Implement servicing, descaling
      shower fittings been serviced, descaled                 and disinfection as per the
      and disinfected?                                        guidance.




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Section 3(17): Preventing Legionnaires Disease


Recommendations

(*Delete as appropriate)

*1	    The survey has identified a number of items ( ) where action is required. This action is
       detailed on the attached Corrective Action Form (L2).

*2	    There no items requiring action and therefore the system is compliant with the Code of
       Practice for preventing Legionnaires Disease.

The works identified by this annual inspection must be implemented to ensure compliance with
Bracknell Forest Borough Council’s guidance for preventing Legionnaires Disease.




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Section 3(17): Preventing Legionnaires Disease



                                ANNUAL WATER SYSTEM SURVEY SUMMARY (L4)

Name and address of premises: .................................................................................................


.....................................................................................................................................................


.....................................................................................................................................................



Review of conditions




Summary of any action taken to remedy any defects:




Survey completed by: ................................................................


           (Signed)..........................................................................


           (Print name) ..................................................................


           (Title) .............................................................................


           Date:...............................................................................


NB:        Copies of this survey form should be sent to the appropriate Director of Environment.




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Section 3(17): Preventing Legionnaires Disease


                     MAINTENANCE, REPAIRS AND ALTERATIONS (L5)

                                           Premises: ................................................................



  Date           Details of work             Details of subsequent                             Authorised
                  undertaken              disinfection (including date)                         signature




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