2007/8 Tooborac E.coli 1orgs/100ml 96.2% samples no e.coli (2 positive)
2009/10 Tooborac E.coli 4orgs/100ml 98.1% samples no e.coli (1 positive)
13/12/11 Toobarac E.coli 1/100mL
2013/14 Tooborac E.coli 1/100mL (98.1% samples no e.coli ) (1 positive)
12/1/23: Tooborac • A routine sample collected from the Tooborac contact point was positive for the presence of E. coli (1 cfu/100mL).
• There was no source of contamination identified.
Corrective actions:
• The chlorine residual was verified.
• Operational data for the Heathcote WTP (which supplies the Tooborac WSL) was reviewed to ensure there had been no issues at the WTP.
• The break tank (located between Heathcote and Tooborac) and the Tooborac tanks were inspected for any signs of contamination, with none being found.
• Tooborac’s water mains were flushed, and sampling undertaken.
• All samples collected verified safe drinking water was being supplied.
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
2005/06 – Tooborac (Victoria) – Trichloroacetic Acid/Dichloroacetic Acid
2005/06 – Tooborac (Victoria) – Trichloroacectic Acid 0.220mg/L
2010/11 Tooborac Dichloroacetic Acid 0.12mg/L
2010/11 Tooborac Trichloroacetic Acid 0.15mg/L
Australian Guidelines Trichloroacetic Acid 0.100mg/L
“Chloroacetic acids are produced in drinking water as by-products of the reaction between chlorine and naturally occurring humic and fulvic acids. Concentrations reported overseas range up to 0.16mg/L and are typically about half the chloroform concentration. The chloroacetic acids are used commercially as reagents or intermediates in the preparation of a wide variety of chemicals. Monochloroacetic acid can be used as a pre-emergent herbicide, dichloroacetic acid as an ingredient in some pharmaceutical products, and trichloroacetic acid as a herbicide, soil sterilant and antiseptic.” Australian Drinking Water Guidelines – National Health and Medical Research Council…
There are no epidemiological studies of TCA carcinogenicity in humans. Most of the human health data for chlorinated acetic acids concern components of complex mixtures of water disinfectant by-products. These complex mixtures of disinfectant by-products have been associated with increased potential for bladder, rectal, and colon cancer in humans [reviewed by Boorman et al. (1999); Mills et al. (1998)].” Ref: tmp/Trichloroacetic acid (TCA) CASRN 76-03-9 IRIS US EPA.htm
Tooborac (Victoria) – Trihalomethanes
2005/06: Tooborac (Victoria) – Trihalomethanes 350μg/L (maximum during year)
2006/07: Tooborac (Victoria) – Trihalomethanes 320μg/L (maximum during year)
Trihalomethanes Australian Guideline Level 250μg/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”. US EPA
Tooborac (Victoria) Lead
2013/14 Tooborac Lead 0.023mg/L
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
Tooborac (Victoria) – Hardness
2006/07: Tooborac (Victoria) Hardness 270mg/L (max)
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.”
Tooborac (Victoria) Total Dissolved Solids
2006/07: Tooborac (Victoria) – Total Dissolved Solids 1300 EC Units
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.
Tooborac (Victoria) – Colour
2010/11 Tooborac Colour 20HU
Based on aesthetic considerations, true colour in drinking water should not exceed 15 HU.
“… Colour is generally related to organic content, and while colour derived from natural sources such as humic and fulvic acids is not a health consideration, chlorination of such water can produce a variety of chlorinated organic compounds as by-products (see Section 6.3.2 on disinfection by-products). If the colour is high at the time of disinfection, then the water should be checked for disinfection by-products. It should be noted, however, that low colour at the time of disinfection does not necessarily mean that the concentration of disinfection by-products will be low…
Tooborac – Victoria – Iron
2007/8 Tooborac Iron 0.42mg/L
2010/11 Tooborac Iron 0.6mg/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
Tooborac (Victoria) – Turbidity
2009/10 Tooborac Turbidity 7.8 NTU
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
22/2/18: Tooborac (Victoria) – Nickel
A sample, collected from the distribution system as part of Coliban Water’s sampling
program, had an elevated level of nickel (0.140 mg/L), exceeding the health-based guideline value for nickel (0.02mg/L) in the ADWG. The investigation undertaken has concluded that the nickel exceedance appears to be an unexplainable anomaly. It was an isolated incident and not an ongoing issue, and the probable cause of the elevated nickel result was contamination during sampling procedures.
Nickel: ADWG Health Guideline 0.02mg/L. A chemical element and silvery white corrosion resistant metal with a golden tinge. 60% of nickel production is used in nickel steel (particularly stainless steel). In water, mainly a problem with nickel plated fittings. Main releases to the environment are from the burning of fossil fuels and in waste discharges from electroplating industries.