During the construction phase, potential impacts on water quality could result from contaminated runoff from the project site and sewage produced by on-site work force. Runoff could be contaminated with sediment, cement material, and accidently discharged fuel and lubricants.

Most of the modification works will be carried out within the existing buildings, and the foundation works for the new buildings are related small scale and will last for a few months. New building works will not increase the suspended solids concentration significantly.

Approximately 30 m³/day of sewage will be generated onsite, the sewage will be collected within existing CSPC facilities and disposed to the public sewer.