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
Korong Vale – Victoria – Iron (highest level only)
2007/8 Korong Vale Iron 0.3mg/L
2008/9 Korong Vale Iron 0.36mg/L
2016/17: Korong Vale (Victoria) – Iron 0.35mg/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
Korong Vale – Victoria – Total Dissolved Solids
2005/06: Korong Vale (Victoria) – Total Dissolved Solids 1500 μS/cm (max), 680μS/cm (min)
2006/07: Korong Vale (Victoria) – Total Dissolved Solids 1500 μS/cm (max)
2009/10 Korong Vale Total Dissolved Solids 2700mg/L
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
Korong Vale (Victoria) – Turbidity
2006/07- Korong Vale (Victoria) – Turbidity 7.7NTU (max)
2008/9 Korong Vale Turbidity 6.3NTU
2011/12 Korong Vale Turbidity 7.6NTU
2017/18 Korong Vale Turbidity 6.6NTU, 0.9NTU (av.)
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
Korong Vale (Victoria) – Hardness
2006/07: Korong Vale (Victoria) Hardness 230mg/L (max)
2008/9 Korong Vale Hardness 250mg/L
2009/10 Korong Vale Hardness 210mg/L
GUIDELINE
“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.”
Korong Vale (Victoria) – Chloride
2007/8 Korong Vale Chloride 290mg/L
2008/9 Korong Vale Chloride 300mg/L
2009/10 Korong Vale Chloride 330mg/L
“Chloride is present in natural waters from the dissolution of salt deposits, and contamination from effluent disposal. Sodium chloride is widely used in the production of industrial chemicals such as caustic soda, chlorine, and sodium chlorite and hypochlorite. Potassium chloride is used in the production of fertilisers.
The taste threshold of chloride in water is dependent on the associated cation but is in the range 200–300 mg/L. The chloride content of water can affect corrosion of pipes and fittings. It can also affect the solubility of metal ions.
In surface water, the concentration of chloride is usually less than 100 mg/L and frequently below 10 mg/L. Groundwater can have higher concentrations, particularly if there is salt water intrusion.
Based on aesthetic considerations, the chloride concentration in drinking water should not exceed 250 mg/L.
No health-based guideline value is proposed for chloride.” 2011 Australian Drinking Water Guidelines
2008/9 – Korong Vale – Sodium
2008/9 Korong Vale Sodium 180mg/L
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