2015/20 – Carnarvon (Western Australia). Hardness, Total Dissolved Solids, Chloride

Carnarvon – (Western Australia) – Hardness

2015/16 Carnarvon (Western Australia) Hardness 200mg/L (max), 200mg/L (mean)

2017/18 Carnarvon (Western Australia) Hardness 230mg/L (max), 200mg/L (mean)

2019/20: Carnarvon (Western Australia) Hardness 200mg/L (max), 195mg/L (mean)


“To minimise undesirable build‑up of scale in hot water systems, total hardness (as calcium
carbonate) in drinking water should not exceed 200 mg/L.

Hard water requires more soap than soft water to obtain a lather. It can also cause scale to form on hot water pipes and fittings. Hardness is caused primarily by the presence of calcium and magnesium ions, although other cations such as strontium, iron, manganese and barium can also contribute.”

Australian Drinking Water Guidelines 2011

Carnarvon – (Western Australia) – Total Dissolved Solids

2016/17 Carnarvon (Western Australia) Total Dissolved Solids 603mg/L (max), 599mg/L (mean)

2017/18 Carnarvon (Western Australia) Total Dissolved Solids 647mg/L (max), 586mg/L (mean)


“No specific health guideline value is provided for total dissolved solids (TDS), as there are no
health effects directly attributable to TDS. However for good palatability total dissolved solids
in drinking water should not exceed 600 mg/L.

Total dissolved solids (TDS) consist of inorganic salts and small amounts of organic matter that are dissolved in water. Clay particles, colloidal iron and manganese oxides and silica, fine enough to pass through a 0.45 micron filter membrane can also contribute to total dissolved solids.

Total dissolved solids comprise: sodium, potassium, calcium, magnesium, chloride, sulfate, bicarbonate, carbonate, silica, organic matter, fluoride, iron, manganese, nitrate, nitrite and phosphates…” Australian Drinking Water Guidelines 2011

Carnarvon (Western Australia) – Chloride

2018/19: Carnarvon Chloride 440mg/L (max), 435mg/L (mean)

“Chloride is present in natural waters from the dissolution of salt deposits, and contamination from effluent disposal. Sodium chloride is widely used in the production of industrial chemicals such as caustic soda, chlorine, and sodium chlorite and hypochlorite. Potassium chloride is used in the production of fertilisers.

The taste threshold of chloride in water is dependent on the associated cation but is in the range 200–300 mg/L. The chloride content of water can affect corrosion of pipes and fittings. It can also affect the solubility of metal ions.

In surface water, the concentration of chloride is usually less than 100 mg/L and frequently below 10 mg/L. Groundwater can have higher concentrations, particularly if there is salt water intrusion.

Based on aesthetic considerations, the chloride concentration in drinking water should not exceed 250 mg/L.

No health-based guideline value is proposed for chloride.” 2011 Australian Drinking Water Guidelines