Water Quality

Westernport Water must provide drinking water that is safe to consume. Safe water is defined in the Safe Drinking Water Act, 2003. The Act, administered by the Department of Health and Human Services requires Westernport Water to meet prescribed public health requirements.

Further information on relevant legislation can be found here: Drinking water Legislation


We test water quality everyday at our sole water storage Candowie Reservoir, and furthermore, we test water quality throughout the distribution system to ensure the highest possible water quality at your tap.

An article published by Coast Magazine helps to explain how we test our water and why – Water Quality with Westernport Water (229 KB)


Monthly summaries of drinking water quality specific to your region are provided below.

Water Quality Monthly Results

Bass Locality – (incorporating Bass and Woolamai) (114 KB)

Cape Woolamai (incorporating Cape Woolamai, Smiths Beach, Sunderland Bay, Sunset Strip and Wimbledon Heights) (114 KB)

Corinella Locality – (incorporating Corniella, Coronet Bay and Tenby Point) (114 KB)

Cowes Locality – (incorporating Cowes, Red Rocks and Silverleaves) (114 KB)

Grantville Locality – (incorporating Grantville, Deep Creek Estate and Pioneer Bay) (114 KB)

Kilcunda Locality – (incorporating Kilcunda, Dalyston and Archies Creek) (114 KB)

Rhyll Locality – (114 KB)

San Remo Locality – (incorporating San Remo and Newhaven) (113 KB)

Ventnor – Locality (incorporating the Penguin Parade and Nobbies tourist atractions (114 KB)

Water Hardness

What is water hardness?

Hardness is the measure of calcium carbonate in water, measured in milligrams per litre (mg/L). Hardness levels depend on mineral deposits (i.e. rocks and soils) from the catchment that supply our water.

Difference between hard and soft water

Hard water is water that has a high mineral content. The quickest way to work out whether your water is hard is to try to lather soap. If it doesn’t lather up, your water is hard. If it lathers extremely easily, then it is soft. The Australian Drinking Water Guidelines (2011) have a scale (see below) of water hardness as it impacts on water quality.

Westernport Water’s supply ranges from 50-120 mg/L with a median result over the last 7 years of 93 mg/L – which is considered as ‘good quality’ under the Australian Drinking Water Guidelines

What does this mean for my tap water?

When hard water is heated, the minerals that cause hardness come out of the water and are deposited as scale. This can affect kettles, hot water services, pipes and fittings. Scale is harmless, but over time it builds up.

The most common way to reduce the build up of scale is keeping hot water systems below 60 degrees Celsius. Some uncommon methods are installing a water softener to bring to an unacceptable level. However results show that Westernport Water’s supply is in a good quality range therefore we do not recommend you drink softened water. Softeners can significantly increase the level of salt in your water.

Some dishwashers have settings that control the addition of salt, which acts like a water softener and decreases the build-up of scale. Generally dishwashers quote a quality range of water in mmol/L. To convert the measurement from mg/L to mmol/L for dishwasher references you simply divide by 100. Therefore the range of Westernport Water’s supply in mmol/L is 0.5-1.2 and for the median, 0.93 mmol/L

Household water quality issues

There are a number of common problems experienced by customers. These are most often associated with how water smells, tastes or looks. Common problems are listed here: Read More

Water Meter reading

Find the source of your issue

The first step to defining a potential WQ problem is finding the source of the issue. You can find steps on how to do this here… Read More