Ampilawatja – Northern Territory – Hardness
2007/08: Ampilawatja Hardness 512mg/L
2008/09: Ampilawatja Hardness 492mg/L
2009/10: Ampilawatja Hardness 398mg/L
2010/11: Ampilawatja Hardness 446mg/L
2013/14: Ampilawatja Hardness 446mg/L
2015/16: Ampilawatja Hardness 456mg/L
2016/17: Ampilatwatja Hardness 502mg/L
2020/21: Ampilatwatja Hardness 500mg/L
“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
Ampilawatja – Northern Territory – Total Dissolved Solids
2007/08: Ampilawatja Total Dissolved Solids 1000mg/L
2010/11: Ampilawatja Total Dissolved Solids 993mg/L
2013/14: Ampilawatja Total Dissolved Solids 987mg/L
2015/16: Ampilawatja Total Dissolved Solids 958mg/L
2016/17: Ampilatwatja Total Dissolved Solids 992mg/L
2020/21: Ampilatwatja Total Dissolved Solids 900mg/L (max), 900mg/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
Ampilawatja – (Northern Territory) – Iodine
2007/08: Ampilawatja Iodine 0.23mg/L
2008/09: Ampilawatja Iodine 0.18mg/L
2009/10: Ampilawatja Iodine 0.17mg/L
2010/11: Ampilawatja Iodine 0.18mg/L
2013/14: Ampilawatja Iodine 0.17mg/L
Iodide: Based on health considerations, the concentration of iodide in drinking water should
not exceed 0.5 mg/L.
Iodine: No guideline value has been set for molecular iodine.
The element iodine is present naturally in seawater, nitrate minerals and seaweed, mostly in the form of iodide salts. It may be present in water due to leaching from salt and mineral deposits. Iodide can be oxidised to molecular iodine with strong disinfectants such as chlorine.
Molecular iodine solutions are used as antiseptics and as sanitising agents in hospitals and laboratories.
Iodine is occasionally used for the emergency disinfection of water for ﬁeld use but is not used for disinfecting larger drinking water supplies. Iodide is used in pharmaceutical and photographic materials. Iodine has a taste threshold in water of about 0.15 mg/L.
Iodide occurs in cows’ milk and seafood. Some countries add iodide to table salt to compensate for iodide-deﬁcient diets.