2007/18 – Bremer Bay (Western Australia) – Hardness, Total Dissolved Solids, Sodium

Bremer Bay – Western Australia – Hardness

2007/08: Bremer Bay (Western Australia) – Hardness 216mg/L (Highest Detection Only)


“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

Bremer Bay – Western Australia – Total Dissolved Solids

2007/08: Bremer Bay (Western Australia) – Total Dissolved Solids 924 mg/L (max)

2008/09: Bremer Bay (Western Australia) – Total Dissolved Solids 932 mg/L (max), 922 mg/L (mean)

2010/11 Bremer Bay (Western Australia) Total Dissolved Solids 909mg/L (max), 867mg/L (av)

2011/12 Bremer Bay (Western Australia) Total Dissolved Solids  996mg/L (max), 925mg/L (av)

2013/14 Bremer Bay (Western Australia) Total Dissolved Solids  904mg/L (max), 902mg/L (av)

2014/15 Bremer Bay (Western Australia) Total Dissolved Solids 930mg/L (max), 895mg/L (av)

2015/16 Bremer Bay (Western Australia) Total Dissolved Solids 895mg/L (max), 880mg/L (av)

2016/17 Bremer Bay (Western Australia) Total Dissolved Solids 879mg/L (max), 872mg/L (av)

2017/18 Bremer Bay (Western Australia) Total Dissolved Solids 687mg/L (max), 685mg/L (av)


“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

2013/14: Bremer Bay (Western Australia) – Sodium

2013/14 Bremer Bay (Western Australia) Sodium 200mg/L (max), 189mg/L (av)

2014/15 Bremer Bay (Western Australia) Sodium 195mg/L (max), 181mg/L (av)

2015/16 Bremer Bay (Western Australia) Sodium 195mg/L (max), 186mg/L (av)

2016/17 Bremer Bay (Western Australia) Sodium 180mg/L (max), 178mg/L (av)

2017/18 Bremer Bay (Western Australia) Sodium 190mg/L (max), 185mg/L (av)

“Based on aesthetic considerations (taste), the concentration of sodium in drinking water
should not exceed 180 mg/L….The sodium ion is widespread in water due to the high solubility of sodium salts and the abundance of mineral deposits. Near coastal areas, windborne sea spray can make an important contribution either by fallout onto land surfaces where it can drain to drinking water sources, or from washout by rain. Apart from saline intrusion and natural contamination, water treatment chemicals, domestic water softeners and
sewage effluent can contribute to the sodium content of drinking water.” ADWG 2011

Bremer Bay (Western Australia) – Silica

2017/18 Bremer Bay (Western Australia) Silica 190mg/L (max), 185mg/L (mean) (listed as Silcon in Water Corporation Water Quality Report 2017-18)

To minimise an undesirable scale build up on surfaces, silica (SiO2) within drinking waters should not exceed 80 mg/L.
Silica present in water is usually referred to as amorphous silica (i.e. lacking any crystalline structure). When silica is dissolved within water it forms monosilicic acid:
SiO2 + 2H2O à Si(OH)4
When the concentrations of monosilicic acid increase, polymerisation of the silica occurs, forming polysilicic acids followed by formation of colloidal silica. Monosilicic acid and polysilicic acids are the forms of silica analysed when determining dissolved silica content.
The deposition of silica from solutions can occur via various mechanisms. The deposition of silica that can cause the most problems for the water industry is via silica’s ability to deposit on solid surfaces that have hydroxyl (OH) groups present. Surfaces that commonly have hydroxyl groups present are glass and metallic surfaces. For example, dissolved silica will react with the surfaces of glass and begin to form a white precipitate. The silica forms silicates on the surface, resulting in silica build-up. In cases where customer complaints occur due to scale build-up, water hardness and silica concentrations should be investigated to determine the cause.
Silica can be a problem in water treatment due to its ability to cause fouling of reverse osmosis (RO) membranes (Sheikholeslami and Tan, 1999, Ning 2002, Sahachaiyunta and Sheikholeslami 2002). This occurs when the dissolved silica of the concentrate becomes super-saturated, causing silicates to form in the presence of metals, and these deposit on the membrane surface. The silicate then dehydrates, forming hard layers on the membrane that reduce the effectiveness of the process… 2011 ADWG