Under the Water Pollution Control Ordinance, effluents discharged from construction activities are subject to control. Licence for water discharge from site has to be applied from the Environment Protection Department with the affiliated terms and conditions being complied with.

Common means against the waste water impacts may include:

1. Installation of waste water treatment plant to collect and treat waste water before discharge
   
   
   Waste water treatment plant

1. Regular testing on wastewater quality after treatment
   
   
   Checking water sample taken from waste water treatment plant

1. Recycling the treated waste water for wheel washing, flushing or other dust suppression systems
   
   
   Use of recycle waste water for wheel washing

1. Clearing away stagnant water to avoid mosquito breeding e.g. trapped water in excavation and other containers
   
   
   Use of light duty sump pump to clear stagnant water on the floor
   
   
   Bamboo poles are cut close to the node or their ends are wrapped up

1. Regular inspections to identify and prevent standing water
   
   
   Materials are fully and smoothly covered with tarpaulin sheets