Minimal impact: The amount of contamination released from marine sediments during dredging for the Central Reclamation Phase III project should be minimal.

Measures to control the environmental impact of dredging and dumping mud for the Central Reclamation Phase III project have been implemented.

The Environmental Protection Department said today the project has gone through the statutory environmental impact assessment process, and the public and the Advisory Council on the Environment have been consulted.

The assessment concluded that with the implementation of the recommended mitigation measures, the amount of contamination released from marine sediments during dredging should be minimal and not result in any adverse impact on surrounding waters.

A monitoring and audit programme is in place to ensure that the environmental impact from the project is kept to within acceptable levels.

The measures include providing silt curtains around the dredging sites, controlling the dredging rate, and using closed-grab dredgers.

Contaminated mud will be disposed at special seabed pits at East Sha Chau using the confined aquatic disposal method.

As the recent court hearing did not grant an injunction, the department expects no problem in issuing permits under the Dumping At Sea Ordinance for the disposal of contaminated mud.

A long-term extensive environmental monitoring programme has been in place since the early 1990s. It consists of water quality, sediment and biota monitoring, together with a risk assessment on the impact on dolphins and humans. No unacceptable impact has been detected.

A Civil Engineering Department team is stationed at East Sha Chau to ensure strict disposal procedures and depth-filling levels are followed and observed.

The daily disposal rate is also regulated to ensure no impact from excessive dumping. Capping of the pit is practised to prevent dispersion of the contaminated mud.

Only specified vessels are allowed to carry out dumping. The barges are equipped with satellite-based Automatic Self-Monitoring Devices to prevent short dumping.