Timor (Victoria) – Trihalomethanes
7 & 8 July 2008 Timor (Customer Tap) – Maryborough System – Trihalomethanes 0.380mg/L. Commissioning of chloramination plant in November 2008 for water quality improvements. Informed DHS. One Section 22 submitted for all THM non-compliances expected to occur
until 30 August 2009. (CHW Water Quality Report 2008/9)
7 October 2008 Timor (Customer Tap) – Maryborough System – Trihalomethanes 0.470mg/L. Commissioning of chloramination plant in November 2008. Informed DHS. One Section 22 submitted for all THM non-compliances expected to occur until 30 November 2008. (CHW Water Quality Report 2008/9)
11 November 2008 Timor (Customer Tap) – (Maryborough System) -Trihalomethanes 0.290mg/L Commissioning of chloramination plant in November 2008. Informed DHS. One Section 22 submitted for all THM non-compliances expected to occur until 31 December 2008. (CHW Water Quality Report 2008/9)
2007/8 Timor 0.560mg/L THM’s (Highest Level Only)
Trihalomethanes Australian Guideline Level 0.25mg/L
Why and how are THMs formed?
“When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, THMs are formed. Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds, THMs. They are tasteless and odourless, but harmful and potentially toxic. The quantity of by-products formed is determined by several factors, such as the amount and type of organic material present in water, temperature, pH, chlorine dosage, contact time available for chlorine, and bromide concentration in the water. The organic matter in water mainly consists of a) humic substance, which is the organic portion of soil that remains after prolonged microbial decomposition formed by the decay of leaves, wood, and other vegetable matter; and b) fulvic acid, which is a water soluble substance of low molecular weight that is derived from humus”. Source: http://water.epa.gov/drink/contaminants/index.cfm
Timor – Victoria – Total Dissolved Solids
2008/9: Timor (Victoria) – Total Dissolved Solids 1600 mg/L (Maximum Level)
2009/10: Timor (Victoria) – Total Dissolved Solids 850 mg/L (Maximum Level)
“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
Timor – Victoria – Hardness
2008/09: Timor (Victoria) – Hardness 840mg/L (Highest Detection Only)
2009/10: Timor (Victoria) – Hardness 370mg/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
Timor – Victoria – Iron
2008/09: Timor (Victoria) – Iron 0.41mg/L (Highest level only)
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