ENG-2003 — Page 348

THE ENVIRONMENT

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permits for general construction work and percussive piling were issued. There were 90 prosecutions for working without permits or violating permit conditions.

In addition, the Government has also phased out the use of noisy diesel, steam and pneumatic piling hammers. The law also requires hand-held percussive breakers and air compressors for construction to meet strict noise standards and to have a 'green' noise emission label before use. In 2003, about 800 labels were issued.

To deter repeated violations of industrial/commercial and construction noise. offences, the Noise Control Ordinance was amended in 2002 to include explicit provisions to hold the top management of a body corporate liable for repeated offences committed by it.

Intruder Alarm and Neighbourhood Noise

The Police Force handles complaints on intruder alarm and neighbourhood noise from domestic premises and public places. In 2003, the police dealt with some 3 600 complaints and 17 offenders were convicted.

Water and Sewerage

Water pollution has increased with urban development and population growth, and Hong Kong now produces more than two million tonnes of sewage every day. The lack of proper treatment for most of the sewage from the generally older urban areas around Victoria Harbour in the past had resulted in poor water quality there. But starting from 2002, following the full commissioning of the first stage of the Harbour Area Treatment Scheme (HATS) at the end of 2001, there has been a marked improvement.

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 34 per cent in 1986 to 76 per cent in 2003, and the percentage in the 'bad' and 'very bad' categories fell from 45 per cent in 1986 to 15 per cent in 2003.

Sewage Treatment and Disposal

To treat wastewater from the main urban area, sewage collected by the local sewerage network on both sides of Victoria Harbour will be directed to the HATS system for treatment and disposal. The HATS, previously known as the Strategic Sewage Disposal Scheme, is a huge project that was originally divided into four stages.

The first stage, which collects sewage from the urban areas of Kowloon, Tsuen Wan, Kwai Tsing, Tseung Kwan O and the north-eastern part of Hong Kong Island for treatment at a sewage treatment plant at Stonecutters Island, was brought into full operation at the end of 2001. In addition to the treatment plant, which some experts considered as one of the most efficient of its kind in the world, the first stage comprises a number of preliminary treatment works at collection nodes, 23.6 kilometres of transfer tunnels up to 150 metres deep, and a tunnelled outfall which disperses the treated effluent into the western anchorage area away from core Victoria Harbour.

Since commissioning, the system has performed well. The Stonecutters Island Sewage Treatment Works, which employs a chemical treatment process, has been consistently removing about 70 per cent of the organic pollutants and 80 per cent of the solids from the sewage prior to discharge. Since the first stage actually treats about