Rocky Gully – Western Australia – Hardness
2010/11 Rocky Gully (Western Australia) Hardness 250mg/L (max), 132mg/L (av)
2011/12 Rocky Gully (Western Australia) Hardness 260mg/L (max), 260mg/L (av)
2013/14 Rocky Gully (Western Australia) Hardness 260mg/L (max), 253mg/L (av)
“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.”
Rocky Gully (Western Australia) Iron
2011/12 Rocky Gully (Western Australia) Iron 1mg/L (max), 0.404mg/L (av)
2013/14 Rocky Gully (Western Australia) Iron 0.6mg/L (max), 0.24mg/L (av)
Based on aesthetic considerations (precipitation of iron from solution and taste),
the concentration of iron in drinking water should not exceed 0.3 mg/L.
No health-based guideline value has been set for iron.
Iron has a taste threshold of about 0.3 mg/L in water, and becomes objectionable above 3 mg/L. High iron concentrations give water an undesirable rust-brown appearance and can cause staining of laundry and plumbing fittings, fouling of ion-exchange softeners, and blockages in irrigation systems. Growths of iron bacteria, which concentrate iron, may cause taste and odour problems and lead to pipe restrictions, blockages and corrosion. ADWG 2011