ENG-1998 — Page 472

THE ENVIRONMENT

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by such severe noise, while only about 100 village houses are within the moderately affected area under more stringent planning controls.

Construction and Demolition

Noise from general construction work between 7 p.m. and 7 a.m., and on public holidays, is controlled through the construction noise permits. The permits restrict the use of equipment according to strict criteria and ban noisy manual activities in built-up areas. Percussive piling is prohibited at night and requires a permit even during daytime. Noisy piling machines may operate up to only three hours a day in urban areas but quieter ones can work up to 12 hours. In 1998, some 2 900 permits were issued. There were about 300 convictions for work without permits or violating permit conditions. Legislation to phase out the use of noisy percussive hammers (including diesel, steam and pneumatic hammers) in built-up areas came into force in April 1998.

To phase out old and noisy equipment, the law requires hand-held percussive breakers and air compressors for construction to meet strict noise standards and to have a 'green' noise emission label. In 1998, about 1 000 labels were issued and there were three prosecutions for operating these products without a label. Over 93 per cent of the labels are issued to newly imported, quiet models.

Hong Kong has strict controls on the use and handling of asbestos. The Air Pollution Control Ordinance bans the import and sale of the more dangerous types of asbestos, namely amosite and crocidolite, from May 1996. It also provides for the control of activities that might lead to asbestos dust emissions. From June 1997, anyone intending to remove asbestos must engage registered asbestos consultants, contractors, supervisors and laboratories, and must submit investigation reports and asbestos abatement plans to the EPD, before starting work. The department also carries out regular inspections to ensure material containing asbestos is handled and disposed of properly.

Marine Dumping

Hong Kong's development projects have generated a vast quantity of dredged mud that is unsuitable for reclamation and other uses (3.1 million cubic metres in 1998). It is dumped at sea in specified mud disposal areas under a permit system. Because of the serious impact illegal dumping has on the marine environment, the EPD maintains strict control over dumping operations under the Dumping at Sea Ordinance. The department also follows the international requirements of the London Convention on marine dumping. Marine dumping of surplus excavated material and construction waste is not permitted unless there is no other environmentally feasible disposal option and marine dumping has no undue adverse impact.

Only an operation carried out by a vessel equipped with an automatic self- monitoring device will be issued a marine dumping permit. This device tracks all marine dumping operations by recording the position and draught of the vessel, so that the authorities can trace any illegal dumping in a cost-effective manner. Moreover, the department's inspectors operate frequent patrols. They prosecute offenders, and repeated offenders may face having their permits revoked or applications for new ones refused.