Water testing

Water is tested to ensure that drinking water is safe to drink and meets established water quality standards. It is also tested to enable the adjustment of treatment processes, to monitor catchment conditions (including during heavy rainfall events), maintain the health of the dams, determine the effectiveness of improvement programs, or for research and development.

Quality control testing is carried out by a NATA-accredited laboratory and NSW Health. The purpose of this testing is to ensure drinking water meets the guidelines set out in our Water Quality Management System.

Process control testing is carried out daily at the water treatment plants by trained operators. This allows us to fine tune the operation of the plants depending on the incoming raw water quality and monitor dosages of treatment chemicals. In addition, there is continuous real-time monitoring of key parameters such as pH, turbidity and chlorine. These analysers can shut the plant down and raise an alarm if values go outside pre-set limits to help ensure the quality of the water leaving the plants.

Where do we test?

Samples are taken from more than 50 different sites at every stage of the supply system. These include:

• Rocky Creek Dam and Emigrant Creek Dam, the Wilsons River and the creeks that enter them.
• Water extraction sites.
• At different stages of treatment and as the water leaves the plant.
• As the water travels through the distribution system in pipelines and reservoirs.
• Consumer sites such as customer taps, parks and community centres.

In addition, our constituent councils also test the water delivered to their customers, which we supply in bulk to reservoirs across the distribution network.

What do we test for?

There are more than 70 physical, chemical, microbiological and radiological parameters that we test for. Some of these parameters include:

• Colour.
• Chlorine.
• Escherichia coli (E.coli).
• Hardness.
• Ammonia, nitrates and nitrites.
• Algae and cyanobacteria (blue-green algae).
• Pesticides and herbicides.
• Metals such as iron, manganese, aluminium, copper, chromium, lead and zinc.
• Disinfection by-products.

Operational target levels for all parameters are set well inside of the published guideline values, so that if the concentration or level of any of the parameters in the water starts to change, action can be taken to address the issue before the guideline value is reached.

Overall, the results of these tests can be used to change the treatment process accordingly to ensure that all water supplied is in accordance with the Australian Drinking Water Guidelines, and to ensure the best water quality possible.