Chapter 16: Water and Sewerage

Water pollution has increased with urban development. Hong Kong produces more than two million tonnes of sewage every day. The lack of proper treatment for most sewage from the urban area around Victoria Harbour has resulted in poor water quality there. However, the situation has shown improvement since the partial commissioning of the Stonecutters Island Sewage Treatment Works. The concentration of sewage bacteria (E. coli) in the central harbour in 2001 was about 6 400 per 100 millilitres.

Progress has been made at bathing beaches. A combination of effective control and the provision of new sewerage has reversed a recent declining trend in the water quality at beaches.

In addition, pollution control at source is now having a positive effect, and river quality is slowly improving. The percentage of rivers in the 'good' and 'excellent' categories increased from 39 per cent in 1991 to 73 per cent in 2001, and the percentage in the 'bad' and 'very bad' categories fell from 41 per cent in 1991 to 8 per cent in 2001.

To treat sewage from the main urban area, sewage collected by the local sewerage network on both sides of Victoria Harbour will be directed to a sewage disposal system called the Harbour Area Treatment Scheme (HATS) for treatment and disposal. The system is divided into Stage I, Stage II and Stage III/IV.

Stage I collects sewage from the urban areas of Kowloon, Tsuen Wan, Kwai Tsing, Tseung Kwan O and the north-eastern part of Hong Kong Island. The Stage I system, which includes 23.6 kilometres of collection tunnels up to 150 metres below the city, was fully completed in late 2001 and commissioning has commenced in phases. The Stonecutters Island Sewage Treatment Works began operation in 1997. It is the world's most efficient chemical enhanced primary treatment plant, removing pollutants almost as efficiently as a conventional secondary treatment plant. Upon full commissioning of the Stage I system in early 2002, the system will collect and treat some 70 per cent of the sewage that enters Victoria Harbour.

The original proposal for Stage II comprised construction of a deep tunnel from Stonecutters Island to discharge the treated effluent in oceanic waters to the south of Hong Kong.

Stage III/IV will collect sewage from the north and south-western part of Hong Kong Island and transfer the effluent to Stonecutters Island for treatment.

In the light of the experience gained during Stage I works, an International Review Panel was set up in April 2000 by the Government to examine whether the original plans remain the most cost-effective and environmentally friendly means for treating the sewage that enters Victoria Harbour. The panel members presented their report in November that year. They have recommended upgrading the treatment of sewage to tertiary level by compact sewage treatment technology. This would then allow treated sewage to be discharged within the harbour via an existing short outfall, thereby obviating the need to build the long outfall as proposed under Stage II. They have also given a number of options for Stage III/IV work for collecting sewage in Hong Kong Island, and recommended some further trials and assessments to verify their viability. In late 2001, the Government commissioned consultants to examine the environmental, engineering and financial feasibility of these proposals in detail. Trials of compact technology and a study on the procurement options are also planned. On the basis of consultants' recommendations, a list of feasible options will be drawn up and the public will be consulted on these feasible options around the end of 2003 or early 2004. Details are available at the Government's home page (http://info.gov.hk/cleanharbour/).

Hong Kong has been divided into 16 areas for which sewerage master plans have been drawn up. The plans identified works estimated at $13.2 billion to bring the sewers up to standard. These works are being carried out in a phased improvement programme. Construction work under the Chai Wan and Shau Kei Wan sewerage master plan was the first completed, in 1997. This was followed by the Tsuen Wan, Kwai Chung and Tsing Yi sewerage master plan in 1998 and the Hong Kong Island South sewerage master plan in 2000. The remaining plans would be implemented by 2009.

To meet needs arising from the revised population projections and the Government's housing programme, the EPD has been studying the sewerage master plans for various areas. Reviews for Central and East Kowloon, Tsing Yi, Tuen Mun, Outlying Islands, Hong Kong Island and North district and Tolo Harbour area are under way. These reviews aim to check the adequacy of the plans and to identify additional sewerage infrastructure to meet future housing needs.

Sewer connections to individual properties are still in progress. Improvements in several parts of Hong Kong Island, Kowloon and the New Territories are well under way. Under the Water Pollution Control (Sewerage) Regulation, the EPD may require house owners to connect their wastewater pipes to new public sewers. In 2001, wastewater from 5 000 people was directed to public sewers so as to avoid water pollution. Since the regulation came into force at the end of 1995, wastewater from 50 200 people has been connected to public sewers.

All water users who discharge their sewage to public sewers pay a basic sewage charge. In addition, 30 trades and industries whose effluent strength exceeds that of domestic sewage also pay a trade effluent surcharge to reflect the additional cost for treating their stronger effluent. These charges aim at recovering partially the operation and maintenance costs of sewage collection, treatment, and disposal facilities and the Government continues to provide funds for capital costs for these facilities from its Capital Works Reserve Fund. Household sewage charge is a modest $1.20 per cubic metre of water consumed with an exemption for the first 12 cubic metres consumed in a four-month billing period. Action is being taken to simplify and streamline the methods and procedures for reassessment of the level of the trade effluent surcharge.

Bathing beaches are an important recreational resource. To protect the health of swimmers, the Government has adopted strict standards for water quality control at bathing beaches. These standards relate to pollution measured as E. coli (the bacteria that can indicate the presence of sewage) and were devised after a thorough study of the health risk facing local bathers. The following table shows how beaches were classified in 2000 and 2001. Beaches in the 'good' and 'fair' categories meet the Government's water quality objective for bathing.

Since 1998, beach water quality gradings for beaches have been made available weekly during the bathing season through the mass media and the EPD's web site (http://www.gov.hk/epd/).

Indiscriminate disposal of waste from the livestock industry was formerly one of the main causes of pollution in streams and rivers in the New Territories. Before the livestock waste control scheme began in 1987, a pollution load from livestock waste equivalent to raw sewage from more than 1.6 million people ended up in Hong Kong's rivers and eventually the sea. Since 1988, the Waste Disposal Ordinance has banned livestock-keeping in new towns and environmentally sensitive areas. Where they are allowed, livestock farms must have proper waste treatment systems.

Under the control scheme, livestock farmers who choose to continue in business could apply for a grant and a loan to help pay for pollution-control facilities. Since the start of the scheme in 1987, about $63 million has been paid out in capital grants. Farmers who chose to cease business could apply for an allowance, and about $883 million has been paid. Livestock waste pollution has been reduced by 97 per cent since the inception of the control scheme.

To help farmers dispose of their livestock waste properly, a door-to-door livestock waste collection service began in 1996. A monthly average of about 5 300 tonnes of livestock waste was collected in 2001.