WASTE DISPOSAL PLAN FOR HONG KONG EXECUTIVE SUMMARY Waste Arisings Hong Kong's waste arisings currently amount to nearly 22,500 tonnes per day (t.p.d.) not including the 49,000 rrr of excavated and dredged materials which are dumped at sea. The main components of these arisings are household waste (approximately 4600 t.p.d.), industrial and commercial wastes (approximately l800 t.p.d.), construction waste (approximately 6500 t.p.d.), livestock waste (approximately 2000 t.p.d.), water works sludges (approximately 4000 t.p.d.) and pulverised fuel ash (approximately 2600 t.p.d.). Waste Collection Wastes are collected and delivered to disposal sites "by the statutory collection authorities (the Urban Council, the Regional Council and the Director of Environmental Protection), by numerous private waste collection contractors and, in the case of some industrial waste, by "in house" labour. The collection authorities collect and deliver for disposal most household, some commercial and most street wastes, some clinical waste and most excremental waste. The remainder is handled by the private sector. Environmental problems, which are generated by both the public and private sector waste collection systems, include odour, leachate spillage, dust, noise and littering. Existing controls over the operations of private sector waste collectors and transporters are fragmented and ineffective. Waste Disposal Most wastes are currently either incinerated at one of three government-operated incineration plants or disposed of at one of five government-operated landfills. The old composting plant at Chai Wan now functions as a temporary bulk transfer facility for the transport of publicly-collected waste to landfill. Incineration plants are reserved primarily for the destruction of publicly-collected household wastes. Privately-collected wastes are disposed of at landfills. Dredged and excavated materials are currently dumped at sea whilst most livestock and chemical wastes are hosed down into the nearest water course (livestock waste) or poured down the nearest drain (chemical wastes). Waterworks sludges are currently discharged either to sea or to inland watercourses. Pulverised fuel ash is either recycled as building materials or stored in specially constructed lagoons. Environmental problems at existing lan<±filtis * include inadequate gas and leachate control, and differential settlement. The main environmental caused by incinerators is air pollution* - II - Future Projections Based on past trends and future projections it is anticipated that daily waste arisings in Hong Kong will continue to increase such that by the year 2001 they will amount to approximately 30,000 t.p.d. This figure includes approximately 5&0 t.p.d. of sewage sludge which will result from planned expansion of the existing sewage treatment capacity and 6550 t.p.d. of waterworks sludge. It also includes 4500 t.p.d. of pulverised fuel ash and furnace bottom ash. However it does not include dredged and excavated materials intended for marine dumping, and wastes diverted for disposal at public dumps. The Strategy The different types of wastes arising in Hong Kong require different methods of treatment and disposal. These methods are : . (a) Dredged and excavated wastes should continue to be dumped at sea in a controlled fashion. .'•••• - - ^;f (b) Sewage and waterworks sludges arising in areas with easy access to deepwater frontage should be dumped at sea initially on an experimental basis with a view to further extension if this method is found environmentally satisfactory; sewage sludge should be stabilised before Such dumping proceeds; waterworks sludge will require thickening to effect economy of transportation. (c) Waterworks sludges not arising in areas with easy access to deepwater frontage should be discharged to coastal waters down long sea outfalls. This is subject to detailed assessment studies on a case by case basis to ensure that no long term damage to the marine ecosystem is caused. (d) Sewage sludge not arising in areas with easy access to deepwater frontage should be ^ewatered. and disposed of at landfill. (e) Excremental waste should be disposed of at sewage works or in limited quantities at landfill. (f ) Livestock waste collected by the government should be f stabilised and composted _grlor_t9 ^S2S2]^sS£ • As all wastes cannot be dealt with in this way," alternatives which require further consideration are: 1} disposal at landfill after stabilisation; ii) disposal at sea after stabilisation; and iii) disposal at sewage works by digestion with sewage sludge. - Ill - (g) Abattoir waste should be regrocessed as far as practicable, and the non-r*e^cTe"aSXe fraction should be disposed of at landfill. ( h ) Animal carcas ses should be _des trpyed .j^L—J-L cremator. r'T :l (i) Clinical waste should wherever possible be , .. iji.cinerat. o rs; to cater for the""was'te g^erated at hospitals, doctors f surgeries and clinics where incineration facilities are not available or cannot meet air emission standards a central incinerator should be constructed. (j) Chemical wastes should wherever possible be codisposed at landfill. Those wastes for which this is not possible should be disposed of at a 1 (k) Radioactive waste should be stored, returned to suppliers or otherwise disposed of in accordance with the directions of the Radiation Board. (1) Pulverised fuel ash and furnace bottom ash should be sold for re-use or lagooned; there is also a possibility, requiring further investigation, that the materials could be used for reclamation and land restoration. (m) All other wastes should be disposed of at landfills, if necessary after treatment at existing incinerators or at transfer stations which are being developed (see below). The Municipal Waste Disposal Strategy The municipal waste disposal strategy is designed to ensure the environmentally acceptable disposal of waste in the 'most cost efficient manner available. Landfills will always be required to dispose of various wastes and the residues from other waste treatment processes (such as Incinerator ash, unuseable construction waste and some chemical wastes) for which there are no acceptable alternative methods of disposal. _Three very large „ landfill __ ^ites__are being.. ^,. dey elopj" e d _ in _ remot QT^JBSSAs^. SJL JtJfcijLJi^^ The s e so a _network_of _ refusei .^ in_t^ r" '_ WasteTjfOT^ or dinary refu^^col .it ^"will^ then, be compacted , containerised and shipjged^ in, ^|)ul|c \\ tos f + the , lan^ril"§. """""TPKe^'ifrrsF ' t wo ' ' * t ransfer^" ¥lta*ibtis'' ' being ^^^^_,_( W^^«L be used principally td handle publicly-collected wastes, but as additional capacity is available, it is intended that transfer stations will also eventually be able to handle privately-coXlected wastes. - IV - Refuse transfer stations coupled with the new landfills will be a comparatively cheap and undoubtedly more environmentally acceptable disposal option than maintaining the existingr* municipal v> incinerators. Environmental problems caused by the incinerators are exacerbated by the fact that they are located in densely populated urban areas. As alternative treatment and disposal facilities become available, these incinerators will therefore be phased out. Any new incinerator that may in future be developed will have to incorporate highly sophisticated pollution control equipment allied to a waste segregation and recycling facility, and they would be located in remote areas. N NEW TERRITORIES UEN MUN TSUEN WAN ROAD TRANSFER BARGETRANSFER © LANDFILL TRANSFER STATION The strategy for the management of municipal waste - V - Livestock & Chemical Waste Control In order to treat livestock manure collected under the waste control programme a number of waste consolidation/composting plants are planned at various locations in the New Territories. A chemical waste treatment centre is also planned at Tsing Yi to tie in with a new regulatory programme for chemical waste disposal. Tentative Programme Working to a planning horizon of 2001 and subject to the availability of resources the programme for the development of new facilities and the closure of old ones is : Year Event 1989 • Lai Chi Kok incinerator Station B closed down upon recommissioning of Station A 1990 . Expansion of composting plant at Ngau Tarn Mel to 25 t.p.d* capacity Refuse transfer station commissioned in Kowloon Bay Lai Chi Kok incinerator Station A and Jordan Valley landfill closed when Kowloon Bay transfer station commissioned 1991 * Chai Wan pulverisation plant closed - 92 down Livestock waste consolidation site commissioned at Site A in north east New Territories Livestock waste consolidation site commissioned in south west New Territories Sludge disposal facility commissioned at Sha Tin for marine dumping Chemical waste treatment centre incorporating a Marpol reception facility commissioned at Tsing Yi WENT landfill commissioned Island East transfer station commissioned In Chai Wan -.-... Kennedy Town incinerator closed down Pillar Point Valley landfill closed VI - Year Event 1993 . Shuen Wan landfill closed upon - 94 commissioning of NENT landfill Island West transfer station commissioned in Western district Transfer station commissioned in Yuen Long/Tuen Mun Transfer station commissioned in Sha Tin Livestock waste consolidation site commissioned in north west New Territories Livestock waste consolidation site commissioned at Site B in north east New Territories Junk Bay landfill closed upon commissioning of SENT landfill Centralised incineration facility for