Gibson (Western Australia) – pH (acidic)

Average pH: 2007 July-2008 June: 6.33 pH units

Based on the need to reduce corrosion and encrustation in pipes and fittings, the pH of
drinking water should be between 6.5 and 8.5.

New concrete tanks and cement-mortar lined pipes can significantly increase pH and
a value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in
microbiological quality.

pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

One of the major objectives in controlling pH is to minimise corrosion and encrustation in pipes and fittings. Corrosion can be reduced by the formation of a protective layer of calcium carbonate on the inside of the pipe or fitting, and the formation of this layer is affected by pH, temperature, the availability of calcium (hardness) and carbon dioxide. If the water is too alkaline (above pH 8.5), the rapid deposition and build-up of calcium carbonate that can result may eventually block the pipe.

Gibson – Western Australia – Total Dissolved Solids

2007/08: Gibson (Western Australia) – Total Dissolved Solids 655 mg/L (Maximum Level)

2008/09: Gibson (Western Australia) – Total Dissolved Solids 620 mg/L (max), 615 mg/L (mean)

2009/10: Gibson (Western Australia) – Total Dissolved Solids 640 mg/L (max)

2010/11 Gibson (Western Australia) Total Dissolved Solids 641mg/L (max), 631mg/L (mean)

2011/12 Gibson (Western Australia) Total Dissolved Solids 636mg/L (max), 631mg/L (mean)

2013/14 Gibson (Western Australia) Total Dissolved Solids 650mg/L (max), 636mg/L (mean)

2014/15 Gibson (Western Australia) Total Dissolved Solids 631mg/L (max), 623mg/L (mean)

2015/16 Gibson (Western Australia) Total Dissolved Solids 651mg/L (max), 634mg/L (mean)

2016/17 Gibson (Western Australia) Total Dissolved Solids 625mg/L (max), 622mg/L (mean)

2017/18 Gibson (Western Australia) Total Dissolved Solids 648mg/L (max), 639mg/L (mean)

2018/19: Gibson (Western Australia) Total Dissolved Solids 646mg/L (max), 635mg/L (mean)

2019/20: Gibson (Western Australia) Total Dissolved Solids 667mg/L (max), 645mg/L (mean)

2022/23: Gibson (Western Australia) Total Dissolved Solids 674mg/L (max), 643mg/L (mean)

GUIDELINE

“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