Beechworth (Victoria)
8/03/11 <24hr Beechworth (outlet basin) E.coli : 1org/100mL An individual detection. Investigations could not identify the source. Residual chlorine was present.
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
Beechworth (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.
Beechworth Victoria) – Turbidity
2015/16: Beechworth (low level) Turbidity 6.6NTU
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
Beechworth Reserve Raw Water Basin
2020/21: Beechworth Reserve Raw Water Basin Gross Alpha Activity 0.41 (Bq/L)
Radionuclides (Other beta- and gamma-emitting)
GUIDELINE
No specific guideline values are set for beta- or gamma-emitting radionuclides.
Specific beta- or gamma-emitting radionuclides should be identified and determined only
if gross beta radioactivity (after subtracting the contribution of potassium-40) exceeds 0.5 Bq/L (27.6 Bq of beta activity per gram of stable potassium).
GENERAL DESCRIPTION
Several radionuclides that are classified as beta-particle or gamma-ray emitters may occasionally be present in drinking water. The significant long-lived nuclides in this group are the naturally occurring isotopes potassium-40, lead-210 and radium-228, and artificial radionuclides caesium-137 and strontium-90. Tritium, another nuclide in this group, is present in the environment both from natural sources and as a result of nuclear fall-out and nuclear power generation.
Levels of strontium-90 and caesium-137 in the Australian environment have decreased substantially since atmospheric testing of nuclear weapons ceased, and these radionuclides are not detectable in drinking water. In the absence of a nuclear power industry in Australia, these nuclides are likely to be present in significant concentrations in drinking water only as a result of transient contamination following an event such as a nuclear accident.
Potassium‑40 occurs naturally in a fixed ratio to stable potassium. Potassium is an essential element for humans, and is absorbed mainly from ingested food. Potassium-40 does not accumulate in the body but is maintained at a constant level independent of intake. The average concentration of potassium in an adult male is about 2 g/kg of bodyweight, which gives an activity mass concentration of potassium-40 of 60 Bq per kg of bodyweight. The corresponding value for females is slightly less.
Lead-210, like radium-226, is a decay product of the uranium-238 series. Food is the most important route by which lead-210 enters the human body, and the annual intake depends on diet: highest concentrations are found in fish and other aquatic species. Generally, lead-210 concentrations in drinking water are considerably less than concentrations of either radium-226 or radium-228.
TYPICAL VALUES IN AUSTRALIAN DRINKING WATER
Concentrations of potassium-40 in Australian drinking water supplies vary widely, from below 0.05 Bq/L in surface water sources to more that 1 Bq/L in some supplies drawn from groundwater.
There are only limited data on concentrations of other beta- or gamma-emitting radionuclides such as lead-210, strontium-90 and caesium-137 in Australian drinking water supplies. Lead-210 concentrations are probably below 0.05 Bq/L and concentrations of artificial radionuclides are negligible.