Cudgewa (Victoria) – Clostridium
During the routine collection of compliance samples, the external contracted laboratory identified a dead animal in the Cudgewa CWS Basin on 28 January 2020. The animal was removed, and the basin was batch dosed with chlorine to increase the chlorine residual above 0.5 mg/L.
A Boil Water Advisory was issued and all residents were made aware via SMS notification, social media posts, door knock and letter drop. The CWS basin was super chlorinated and the reticulation was flushed to draw water throughout the system. Microbiological and pathogen (Clostridium, Giardia and Cryptosporidium) testing was conducted with no detections of E. coli, coliforms, Giardia or Cryptosporidium reported. A single spore of Clostridium was identified on 28 January in the sample collected prior to batch chlorination. Additional testing was carried out with no detections of Clostridium. The Boil Water Advisory was lifted on 3 February. North East Water 2019/20 Drinking Water Quality Report
“No guideline value has been set for Clostridium perfringens in drinking water. If used as
an indicator and detected in drinking water, immediate action should be taken, including
investigation of potential sources of faecal contamination.
GENERAL DESCRIPTION
Clostridium spp are anaerobic, sulfite-reducing, spore-forming bacilli. There are a number of species, of which C. perfringens is uniquely of faecal origin. Largely because it is anaerobic, C. perfringens rarely multiplies in water environments.
The spores are smaller than protozoan cysts and oocysts. They are exceptionally resistant to unfavourable conditions in water environments, including temperature and pH extremes, and are also resistant to disinfection processes such as chlorination.
SOURCE AND OCCURRENCE C. perfringens is a member of the normal intestinal flora of 13-35% of humans, and is relatively common in dogs but less so in other warm-blooded animals (Leeming et al. 1998). The numbers excreted in faeces are normally substantially lower than those of Escherichia coli. C. perfringens and its spores are commonly present in sewage.” ADWG 2011
Cudgewa (Victoria) – Trichloroacetic Acid
2010/11: Cudgewa 0.110mg/L Trichloroacetic Acid
(Australian Guideline Trichloroacetic Acid 0.1mg/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
Cudgewa – Victoria – Iron
2007/08: Cudgewa (Victoria) – Iron 0.31mg/L
2012/13: Cudgewa Iron 0.42mg/L
2014/15: Cudgewa Iron 0.9mg/L
2015/16: Cudgewa Iron 0.31mg/L
2016/17 Cudgewa Iron 0.32mg/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
Cudgewa (Victoria) – Turbidity
2009/10: Cudgewa Turbidity 7.7NTU
2010/11: Cudgewa Turbidity 27NTU
2011/12: Cudgewa Turbidity 12NTU
2012/13: Cudgewa Turbidity 5.5NTU
2013/14: Cudgewa Turbidity 13NTU
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
Cudgewa (Victoria) – Aluminium
2016/17: Cudgewa Aluminium 1.5mg/L
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.