Hardness is caused predominantly by Calcium and Magnesium salts in the water. The presence of these salts is generally naturally occurring. Hard water may cause scaling issues, problems such as soap not lathering, blocked shower roses, blackened aluminium cooking utensils and/or white deposits on your sink or inside your dishwasher.

Problems experienced due to new cement lined water mains occur mainly in new subdivisions where mains have been recently laid. Under these circumstances, the problem is generally only temporary until the pipes stabilise.

Most water supplied to Western Water customers has very low hardness. Some customers, such as those supplied by bore water or receivng water from new cement- lined water mains may have hard water.

Sometimes we receive enquiries from customers about the hardness of their water supply, when they purchase a new dishwasher. Instruction manuals provided with new dishwashers usually highlight water hardness as an issue requiring attention. However, user manuals may express hardness levels in units other than milligrams per litre (mg/L), such as millimoles (mmol) or parts per million (ppm).

Note, the unit milligrams per litre (mg/L) is equivalent to parts per million (ppm).

For conversion of Total Hardness (as Calcium Carbonate) from milligrams per litre (mg/L) to millimoles per liter (mmol/L), divide (÷) mg/L value by 100 to give Total Hardness in mmol/L.

For conversion from milligrams per liter (mg/L) to degree of German Hardness (°dH), multiply (×) mg/L value by 0.056.

Water Quality 07/08 Total Hardness Results:

 Water Hardness Results 2007/08

For more information about water hardness please contact Western Water's
Water Quality Team on (03) 9218 5400, during normal business hours.