Water Pollution in HK _stream and marine_

Water Pollution in H.K (stream and marine) Water pollution occurs when a body of water is adversely affected due to the addition of large amounts of materials to the water. When it is unfit for its intended use, water is considered polluted. Main sources of stream pollution and their adverse effects Factories – e.g. dyeing and tanneries factories(漂染廠), leather tanning(皮革廠), electroplating (電鍍廠),power station Adverse effects (chemical pollution) - discharge chemical wastes(some are toxic) and heavy metal salts into the river - poisonous to fish - poisonous to man(through the food chain) Adverse effects - (thermal pollution) - Water withdrawn from the river to cool some industrial process such as that in power station and the hot effluent will raise the water temperature - high temperature decrease the oxygen solubility in water and resulting deoxygenation - upset the aquatic ecosystem Livestock farms – e.g. pig and poultry farms Adverse effects - large amount of manure is disposed into the streams with little treatment. - Unpleasant smelling gases: methane(甲烷), ammonia(氨) produced *affect the living condition of the nearby resident - absence of oxygen causes aquatic organisms to die Pesticides (chemical pollution) Adverse effects - pesticides from farmland discharge into the river - poisonous chemicals sprayed to kill aquatic organism - poisonous to man Sources of marine pollution and its adverse effects Factories (chemical and thermal pollution) *same as the stream pollution domestic sources - everyday about 2 million tonnes of domestic sewage(e.g. human sewage is produced - 90% is untreated * serious in the Victoria Harbour Adverse effects - coastal water which heavy loaded with organic wastes maybe cause eutrophication(營養化) and give rise to red tides - some red tides are toxic and the toxin may accumulates in the shellfish and threaten the health of people when being eaten - dissolved oxygen content in the water will reduce and fish will be suffocated to death - polluted water gives out unpleasant odour - many beaches are polluted ,Bacteria, nutrients and other pollutants can make swimmers sick Transport - oil spillage from ships occasionally contaminates the sea - caused by wreck of oil tankers, cleaning of the tanks and seeping from shipping and shipyards. - The spilled oil covering the seashores kill seaweeds(海藻), crustaceans(甲殼類) - The spilled oil kill sea birds because of the following reasons: i.The sea birds can’t fly when their feathers become soaked with oil. ii.When the sea birds clean their feathers, they ingest sufficient oil to poison themselves. - The oil contaminates beaches and thus spoils a valuable recreational resource - It is flammable(易燃) - Oil layer prevent oxygen dissolve into the water - Detergent(清潔劑) used can cause another serious pollution. Reclamation and excavation Adverse effects - reduce the rate of flow across the habour. - pollutants easily accumulated in the Victoria Habour - reduces the dissolved oxygen for the aquatic organism Affected areas Discuss in the cases study The remedial measures and their effectiveness 3 directions: 1)controlling at sources(legislation) The EPD controls waste water discharges through the Water Pollution Control Ordinance <<水污染管制條例>>. Operators are required to ensure their discharges meet standards specified by the EPD, and these specifications are contained in licenses allowing them to discharge their waste water into receiving water bodies. The EPD regularly inspects operators, responds to complaints and will prosecute offenders. 2) Providing Sewers All sewage should be discharged into sewers (污水管道)not Storm water drains(排疏雨水的雨水渠) which are only meant to carry rainwater into the sea. The EPD is trying to ensure everybody is connected to a sewer or,in remote areas, to a properly working septic tank system(化糞池).The department prepares sewerage master plans(污水收集整體計劃) which required to collect the sewage on a catchment-by-catchment basis and direct it to the treatment facilities. The entire territory has been divided into 16 areas, and SMPs have been produced for all of them. The recommendations of these SMPs are being implemented progressively to cater for the present and future development needs of Hong Kong and the work is carried out by the Drainage Services Department. The plans are currently being revised to take into account a projected population increase of about two million by 2016. 3)Collecting and Treating Sewage The Harbour Area Treatment Scheme (HATS)(淨化海港計劃) is a strategy for collecting and treating sewage from around Victoria Harbour. So far, Kowloon and parts of Hong Kong Island have been linked to the Stonecutters Island sewage Treatment works(昂船洲污水處理廠), which was commissioned in 2001. Further stages of the scheme are undergoing trial and studies, as recommended by a panel of international experts in 2000. These should be completed by the end of 2003. ** a collection and treatment system in Tolo Harbour has resulted in a drop in red tides from 43 in 1988 to 16 in 2000. Stonecutters Island Sewage Treatment Works Additional measure A Beach Pollution Response Plan ( 泳灘污染應變計劃 ) Pollution incidents such as breakdown of sewage pumping or treatment facilities, illegal discharge of high-strength commercial or industrial wastewater, etc., may result in a sudden discharge of a large quantity of raw or partially treated sewage in the catchment area of a beach. Depending on the circumstances, the discharged sewage may cause serious pollution to the receiving beach water body, rendering it unsuitable for swimming. A Beach Pollution Response Plan has been formulated by the government in summer 1997 to tackle beach pollution incident effectively. The plan sets out the required emergency responses and actions to be followed by concerned departments and parties such as Environmental Protection Department, Drainage Services Department,Leisure and Cultural Service Department,etc.to tackle the pollution incident and to make a quick decision on whether the beach should be closed temporarily to protect public health Beach Water Quality Improvement Works Sewage pollution of local coastal water becomes an unfortunate byproduct of such growth that the antiquated sewerage system cannot cope with. Beaches with highly populated but inadequately sewered hinterlands are particularly susceptible to pollution. To tackle these pollution problems, comprehensive Sewerage Master Plans (SMPs) covering 16 areas of the whole territory have been proposed for improving the sewerage network of Hong Kong. After the commissioning of all relevant improvement facilities recommended in the SMPs, better beach water quality can be achieved and maintained. Legislation:The livestock waste control scheme(禽畜廢物管制計劃 ) The Livestock Waste Control Scheme (LWCS) was first promulgated in 1987 to control livestock waste pollution (i.e. from the keeping of pigs, chickens, ducks,geese, pigeons or quail). The scheme is revised in 1994 after extensive consultation with the livestock keeping trade.The LWCS makes reference to the following three areas: Control Area - livestock keeping in this area must be licensed by the Director of Agriculture, Fisheries and Conservation (DAFC) and must comply with the Waste Disposal(Livestock Waste)Regulations廢物處置(禽舍)規例 e.g Tolo harbour and part of Tolo channel areas, Part of Sai Kung, Tuen Mun areas,etc. Prohibition Area - livestock keeping is banned in this area e.g All new town areas,Urban areas, Part of Lantau Island, Part of outlying Islands,etc. Restriction Area - no new livestock keeping is allowed in this area; only existing livestock keeping activities either licensed by the DAFC or authorized by the Director of Environmental Protection (DEP) and complying with the Waste Disposal (Livestock Waste) Regulations are allowed. e.g Part of Mui Wo ,Tolo channel ,Tuen Mun ,Sai Kung areas, etc. Effectiveness The EPD has an extensive programme for cleaning up Hong Kong's water which has had good results. The number of Beaches with poor or very poor water quality dropped to seven by 2001,compared with 17 in 1995. The number of rivers and streams with bad or very bad water quality dropped to 10 per cent in 2000, from 52 per cent in 1988. In fact, in 2000, for the first time no river was classified as "very bad". Toxic metal discharges have been reduced from 7,000 kilogrammes per day in 1993 to 2,000 kilogrammes per day in 2000. In Victoria Harbour, the first stage of the Harbour Area Treatment Scheme (HATS) to collect, treat and discharge the sewage generated around the harbour was completed at the end of 2001. Now, 70 per cent of sewage around the Victoria Harbour receives treatment. • Although our water quality has improved within some parameters in recent years, but it is not enough for a clean bill of health, particularly in areas like Inner Deep Bay and Victoria Harbour. An expected growth in population will put added pressure on water quality. • Thus, Individual operators, such as restaurants and factories, can help to make a difference by ensuring they follow anti-pollution laws. • Residents should co-operate with efforts to connect their buildings to sewers. They can also try to reduce their consumption of water, there by reducing the amount of sewage that needs treatment. Reference http://www.epd.gov.hk/epd/ The End