ENG-2013 — Page 300

14

The Environment

Water Quality and Sewerage

Water pollution, if left unchecked, tends to increase with urban development and population growth. The lack of proper treatment for most of the sewage from older urban areas around Victoria Harbour resulted in poor water quality there but since the Harbour Area Treatment Scheme (HATS) Stage 1 went into operation at the end of 2001, there has been a marked improvement. The government is now implementing HATS Stage 2A which will collect and properly treat the remaining 25 per cent of sewage around the harbour.

In addition, pollution control at source has yielded positive results, and river quality has also improved. The percentage of rivers in the 'good' and 'excellent categories increased from 34 per cent in 1986 to 87 per cent in 2013, and the percentage in the 'bad' and 'very bad' categories fell from 45 per cent in 1986 to 6 per cent, with no river falling into the 'very bad' category in 2013.

Marine water quality objectives were introduced under the Water Pollution Control Ordinance and gradually applied to the 10 water control zones from 1982 to 1996. The government commissioned a study in 2008 to review the existing water quality objectives in light of local conditions, overseas best practices and scientific advances; and to examine the technical attainability and potential socio-economic implications of any proposed changes to the water quality objectives. Views from the public and stakeholders on the issues to be addressed and the review approaches were sought in 2009 and a second stage public engagement will be held after any proposed changes to the water quality objectives are formulated.

Sewage Treatment and Disposal

At present, the public sewerage system serves 93 per cent of the population and collects about 2.8 million cubic metres of waste water every day. About 70 per cent of the collected sewage receives chemical or higher levels of treatment before being discharged.

HATS Stage 1 collects sewage from the urban areas of Kowloon, Tsuen Wan, Kwai Tsing, Tseung Kwan O and the north-eastern part of Hong Kong Island and transports it through a network of deep tunnels to Stonecutters Island for treatment. HATS Stage 2A involves extending the deep tunnel system to take the untreated sewage from the remaining parts of Hong Kong Island to the Stonecutters Island Sewage Treatment Works, which will be expanded to provide centralised chemical treatment to sewage from the entire HATS catchment. HATS Stage 2A works commenced in 2009 and the major works will be completed in 2014. Since commissioning in 2010, the Advance Disinfection Facilities have improved water quality in the Western Harbour and at Tsuen Wan beaches. Together with the completion of a local sewerage network and progressive connection to local residents' houses in the vicinity of the Tsuen Wan beaches, this has improved the waters at seven closed beaches so that they now comply with the Water Quality Objective for bathing beaches and are suitable for bathing. The government is studying the measures needed to further improve the water quality of the harbour.

Details of HATS are available on the 'A Clean Harbour for Hong Kong' website, www.cleanharbour.gov.hk.

Apart from HATS, the government has spent a further $25 billion on other sewerage schemes since 1991 and will spend another $17 billion on schemes over the next five years, including

248

Page 300Page 301