Hong Kong and Shenzhen may run into conflict over differing environmental protection standards during the construction of the Shenzhen Western Corridor. The environmental impact assessment report of the bridge project across Deep Bay, which is due to be completed in 2005-2006, was released for public inspection last week. Doubts have been raised by environmentalists on how the standards and mitigation measures mentioned in the report will be enforced, given that Hong Kong and Shenzhen are responsible for the sections of the bridge within their own jurisdictions. The report contains data and analysis on the environmental impact of the Hong Kong section, but only a brief summary on the Shenzhen section. World Wide Fund for Nature conservation manager Alex Yau Shuk-kau said the project would go ahead, even if one of the sides failed to meet environmental standards. 'If silting pollution drifts along the tidal current to the other side during construction and exceeds the standards, who should be held responsible? Could either side ask for the work to be stopped?' she said. Although the Highways Department intends to set up a liaison committee between the Hong Kong and mainland contractors, Ms Yau said the question of cross-border enforcement of environmental standards was unresolved. 'The bridge will be built separately by two governments, but there is only one Deep Bay with one ecological system,' she said. According to the assessment report, the flow of water in Deep Bay would slow down by four per cent, resulting in a higher rate of sedimentation. The report proposes clearing the oyster bed in Lau Fau Shan to increase flow.