2008/13 – Stuarts Point (New South Wales) – E.coli, Turbidity, Arsenic, Lead, Iron, Selenium

Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. While tests for thermotolerant coliforms can be simpler than for E. coli, E. coli is considered a superior indicator for detecting faecal contamination…” ADWG 2008/13 Stuarts Point (NSW) – Lead 2008/13 – Stuarts Point (NSW) – Lead 0.022mg/L (max) 0.0014mg/L (mean) Lead Australian Drinking Water Guideline 0.01mg/L “… Lead can be present in drinking water as a result of dissolution from natural sources, or from household plumbing systems containing lead. These may include lead in pipes, or in solder used to seal joints. The amount of lead dissolved will depend on a number of factors including pH, water hardness and the standing time of the water. Lead is the most common of the heavy metals and is mined widely throughout the world. It is used in the production of lead acid batteries, solder, alloys, cable sheathing, paint pigments, rust inhibitors, ammunition, glazes and plastic stabilisers. The organo-lead compounds tetramethyl and tetraethyl lead are used extensively as anti-knock and lubricating compounds in gasoline…ADWG 2011 2008/13 Stuarts Point (NSW) – Iron 2008/13 – Stuarts Point (NSW) – Iron 2.79mg/L (max), 0.21mg/L (mean) From a total of 246 samples, 5 exceedances occurred from 1 Jan 2004 to 31 Mar 2014. The ADWG value for iron based on aesthetic considerations is 0.3 mg/L. 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 2008/13 – Stuarts Point (New South Wales) – Arsenic 2008/13: Stuarts Point Arsenic 0.03mg/L (max), 0.0026mg/L (mean) Arsenic: Australian Drinking Water Guideline = 0.01mg/L Arsenic is bioaccumulative and symptoms may take 10-15 years to develop after expsoure at high levels. Drinking water can be contaminated with inorganic arsenic through wind blown dust, leaching or runoff from soil, rocks and sediment. Groundwater sources such as bores will usually have higher arsenic levels than surface water. In major Australian reticulated water supplies concentrations of arsenic range up to 0.015mg/L, with typical values less than 0.005mg/L. https://www.health.qld.gov.au/ph/documents/ehu/2676.pdf 2008/13 – Stuarts Point (New South Wales) – Turbidity 2008/13: Stuarts Point (New South Wales) Turbidity 9.73NTU (max), 0.63 NTU (mean) Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment process to address identified risks from Cryptosporidium and Giardia, it is essential that filtration is optimised and consequently the target for the turbidity of water leaving individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with chlorine unless a higher value can be validated in a specific context. Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the consumer’s tap. Stuarts Point (New South Wales) – Selenium 2008-2013: Stuarts Point Selenium 0.003mg/L (max), 0.0011mg/L (mean) Based on health considerations, the concentration of selenium in drinking water should not exceed 0.004 mg/L (2011-2025 guideline 0.01mg/L). “General description Selenium (Se) and selenium salts are widespread in the environment. Selenium is released from natural and human-made sources (such as the burning of coal). Selenium is also a by-product of the processing of sulfide ores, chiefly in the copper refining industry. The major use of selenium is in the manufacture of electronic components. It is used in several other industries, and selenium compounds are used in some insecticides, in hair shampoos as an antidandruff agent, and as a nutritional feed additive for poultry and livestock. Selenium copper alloys have also been identified as a potential replacement for lead copper alloys in plumbing products. Further information on lead replacements in plumbing products (such as selenium copper alloys) is available in Information Sheet 4.1 – Metal and metalloid chemicals leaching from plumbing products. Selenium concentrations in drinking water source waters are generally very low and depend on local geochemistry, climatic conditions (e.g. drought), pH and the presence of iron salts. Selenium in water is mainly present as inorganic compounds, predominantly selenate. Weathering of rocks and soil may result in low levels of selenium in water, which may be taken up by plants (SLR 2022). Food is the major source of intake for Australians. Cereal and grain products contribute most to intake, while fish and liver contain the highest selenium concentrations.” ADWG 2025