Water Quality

Keeping Our Water Clean

Singapore is a country with limited water resources, and it is essential for its water quality to be carefully regulated. The National Environment Agency (NEA) regulates water pollution and quality in Singapore's sewerage system, as well as inland water bodies and coastal areas.

To keep Singapore’s water clean, soil pollution must also be controlled, as pollutants in the soil can enter the water system as run-off or groundwater. Soil pollution control in Singapore focuses mainly on the proper use of approved pesticides to control termites.

Our sewerage system

Singapore's public sewerage system serves all industrial estates and almost all residences. The Public Utilities Board (PUB) regulates the sewerage system, as well as the treatment and discharge of industrial wastewater into public sewers.

All wastewater must be discharged into the public sewerage system. The discharge of wastewater into open drains, canals and rivers is regulated by the Environmental Protection and Management Act (EPMA) and the Environmental Protection and Management (Trade Effluent) Regulations. The EPMA and its regulations are administered by NEA’s Pollution Control Department (PCD).

Industrial wastewater must be treated to specified standards before being discharged into a sewer or watercourse if a public sewer is not available. More information on the required standards can be found here.

Additionally, industries which generate large quantities of acidic effluent are required to install a pH-monitoring and shut-off control system to prevent acidic effluent from being discharged into public sewers.

Industries may apply to PUB for permission to directly discharge trade effluent containing biodegradable pollutants into public sewers, with a tariff payment.The tariff will be determined by how much their biochemical oxygen demand (BOD) and total suspended solids (TSS) loading exceeds allowable standards.

Inland and coastal waters

The water quality of both inland water bodies and coastal areas is regularly monitored. For inland water bodies, the parameters monitored include pH, dissolved oxygen, biochemical oxygen demand, total suspended solids, ammonia and sulphide. Coastal water samples are analysed for metals, total organic carbon, and other physical, chemical and bacteriological parameters.

Click below to read more about the NEA’s recreational water quality guidelines and monitoring programme:

Regulation of water quality

NEA regulates the quality of water in public swimming pools, cooling towers and water fountains.

 Click below to read more about regulation of water quality in the above-mentioned areas: