Key pollutants

Key pollutants

SCA officer looking at molecules on computer screen

The Pollution Source Assessment Tool informs us on where in our
drinking water catchments we may need to intervene.

One of the primary objectives of WaterNSW is managing our catchments to keep pollutants from reaching our waterways and water supply.

To help us achieve this we conduct ongoing research which incorporates the latest scientific techniques and knowledge.

Some pollutants are of greater risk to water quality than others - in particular pathogens, nitrogen, phosphorus and suspended solids:

  • Pathogens, such as Cryptosporidium and Giardia, can cause health concerns for water users and are costly to remove from drinking water
  • Nitrogen can lead to the formation of cyanobacteria (blue-green algae) blooms in water bodies
  • Phosphorus (like nitrogen) can lead to the formation of cyanobacteria (blue-green algae) blooms
  • Suspended solids (fine particles from soil and other sources suspended in the water) can clog up water treatment plants, help transport nitrogen and phosphorus, and reduce the effectiveness of UV treatment and natural sunlight in the removal of pathogens.

To assess the risks associated with these pollutants, we use a geographic information tool known as the Pollution Source Assessment Tool (PSAT). This tool informs us on where in our drinking water catchments we may need to intervene.

WaterNSW also monitors other pollutants - such as pesticides, heavy metals and salt - as part of a comprehensive water quality monitoring program. While these pollutants have not caused significant water quality problems in our storages to date, we need to be able to monitor them so that we can adapt our catchment management activities to respond in the future if necessary.


Tuesday 19 October
2,426,378 ML
2,581,850 ML
9,092 ML
1,299 ML
4,444 ML
Tuesday 19 October