4/1/20 – 16/1/20: Omeo (Victoria) – Boil Water Notice
During the East Gippsland bushfires, fires strongly challenged the corporation’s ability to continue supplying water safe for drinking because of the direct impact on some key assets and the unprecedented demand on the water treatment and supply systems. Despite this, supply was maintained with precautionary boil water and do not drink notices only issued where quality could not be guaranteed.
Three Section 22 notifications were issued during the bushfires. The first was issued on 31 December 2019, as a result of the need to bypass secondary chlorination and issue a Boil Water Notice for Mallacoota. The bypass was required to keep up with the unprecedented demand for water. The second was on 3 January 2020, as a result of losing secondary disinfection at Buchan, which required a Do Not Drink Tap Water Advisory Notice to be issued for the township. The third section 22 notification came on 4 January, because of the need to bypass the Omeo Water Treatment Plant and issue a Do Not Drink Tap Water Advisory Notice for the Omeo township to keep up with the extreme level of water demand.
All the notices were successfully lifted in consultation with DHHS, once actions to reinstate each of the water supply system were completed and the delivery of safe drinking water had been restored. Notices were lifted on 1st January 2020 for Mallacoota, 14th January 2020 for Buchan and 16th January 2020 for Omeo.
East Gippsland Water 2019/20 Drinking Water Quality Report
Omeo (Victoria) – Aluminium
According to the ADWG, no health guideline has been adopted for Aluminium, but that the issue is still open to review. Aluminium can come from natural geological sources or from the use of aluminium salts as coagulants in water treatment plants. According to the ADWG “A well-operated water filtration plant (even using aluminium as a flocculant) can achieve aluminium concentrations in the finished water of less than 0.1 mg/L.
The most common form of aluminium in water treatment plants is Aluminium Sulfate (Alum). Alum can be supplied as a bulk liquid or in granular form. It is used at water treatment plants as a coagulant to remove turbidity, microorganisms, organic matter and inorganic chemicals. If water is particularly dirty an Alum dose of as high as 500mg/L could occur. There is also concern that other metals may also exist in refined alum.
While the ADWG mentions that there is considerable evidence that Aluminium is neurotoxic and can pass the gut barrier to accumulate in the blood, leading to a condition called encephalopathy (dialysis dementia) and that Aluminium has been associated with Parkinsonism dementia and amyotrophic lateral sclerosis, the NHMRC, whilst also acknowledging studies which have linked Aluminium with Alzheimer disease, has not granted Aluminium a NOEL (No Observable Effect Level) due to insufficient and contradictory data. Without a NOEL, a health guideline cannot be established. The NHMRC has also stated that if new information comes to hand, a health guideline may be established in the future.
In communication with Aluminium expert Dr Chris Exley (Professor in Bioinorganic Chemistry
The Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire UK) in March 2013 regarding high levels of Aluminium detected in the South Western Victorian town of Hamilton
“It is my opinion that any value above 0.5 mg/L is totally unacceptable and a potential health risk. Where such values are maintained over days, weeks or even months, as indeed is indicated by the data you sent to me, these represent a significant health risk to all consumers. While consumers may not experience any short term health effects the result of longer term exposure to elevated levels of aluminium in potable waters may be a significant increase in the body burden of aluminium in these individuals. This artificially increased body burden will not return to ‘normal’ levels when the Al content of the potable water returns to normal but will act as a new platform level from which the Al body burden will continue to increase with age.
Omeo – Victoria – Iron
2010/11: Omeo (Victoria) – Iron 1.1mg/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