Shepparton (Victoria) – Aluminium
Estimated duration of incident: Isolated Incident
Location of incident: Shepparton
Nature of incident: Acid soluble Aluminium exceedance of 0.50mg/L. Fault at the DAFF plant with the coagulation sample line flow to the dosed pH monitoring instrument. The coagulation sample line rotamotor appears to have restricted the flow causing an incorrect measurement of pH. A pH of 6.7 was displayed on the meter & SCADA; however the actual pH was 5.3 (as confirmed with a hand held meter). The dosing pH was estimated to be out of specification for approximately one hour, which caused soluble aluminium to pass through the filters.
Drinking water supplies potentially effected: Shepparton, Mooroopna, Toolamba and Tallygaroopna
Action taken in response: Immediate action will be to replace the sample line rotamotor with a flow switch. This change is expected to avoid sample line restrictions in future.
Communication with customers: Not Required
DH notification: A Section 18 notification sent to the Department of Health on 31/08/2012.
Shepparton (Victoria) – Aluminium
Estimated duration of incident: Isolated incident
Location of incident: Shepparton
Nature of incident: An acid soluble aluminium result of 1.5 mg/L was detected in the reticulation of Shepparton
Drinking water supplies potentially effected: Shepparton, Mooroopna, Tallygaroopna and Toolamba
Action taken in response: The Clear Water Storage which was sampled at the same time had an aluminium result of 0.21 mg/L. Treatment processes at the plant were investigated and found to be correct. The high result was confirmed by another laboratory and there was no evidence of contamination in the sample bottles themselves
Communication with customers: Nil
DH notification: A Section 18 notification was sent to the Department of Health on 4/07/2014
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.
Shepparton (Victoria) Iron
2019/20: Shepparton (Victoria) Iron 0.85mg/L (max)
2020/21: Shepparton (Victoria) Iron 0.59mg/L (max)
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
Shepparton (Victoria) – Suspended Sediment
3/12/22 + 16/12/22: Increased demand due to warm weather has suspended sediment in sections of the reticulation system that is being detected by customers. Due to the increase in demand additional CWS have been called into service also changing the normal hydraulic flows of the retic that has contributed to the suspension of the sediment in sections
of the reticulation system