Glenn Innes (New South Wales) – E.coli
From a total of 508 samples, 14 detections occurred from 2003 to 2013. The majority of detections occurred in 2004, including the highest detection of 19 cfu/100 ml on 25 Feb. Since 2008, one E.coli was detected on 22 May 2012. Detection dates: 25/02/04, 24/03/04, 21/04/04, 19/05/04, 16/06/04, 01/12/04, 30/11/2005, 08/03/06, 04/10/06, 01/11/06, 28/03/07, 08/10/08, 05/11/08, 22/05/12It is noted that prior to 2008, there were at least 2 exceedances per year. After 2008, only one exceedance occurred in May 2012.
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
Glen Innes (New South Wales) – Turbidity
2003-13: Glenn Innes (New South Wales) – Turbidity. 29.6NTU (max), 0.7NTU (mean)
From a total of 115 samples, two exceedances of turbidity have occurred from 2003 to 2013. The exceedances of 29.6 and 6 NTU occurred on 21 Jan 2004 and 8 Jul 2009, respectively.
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
Glenn Innes (New South Wales) – Colour
2003-13: Glenn Innes (New South Wales) – Colour. 68HU (max), 3HU (mean)
“At times colour is above the ADWG guideline criteria….Generally the colour of treated water at GISC is below the ADWG value, however, large spikes were observed in January 2013 due to an increase in the concentration of manganese in the source water.”
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…
Glenn Innes (New South Wales) – Fluoride
2003-13: Glenn Innes (New South Wales) – Fluoride 1.93mg/L (max), 0.95mg/L (mean)
From a total of 116 samples, there was one exceedance occurring 7 Feb 2012, with a fluoride concentration of 1.93 mg/L. Weekly fluoride monitoring performed by Council has detected 2 fluoride exceedances out of 680 samples.
“Fluoride occurs naturally in seawater (1.4 mg/L), soil (up to 300 parts per million) and air (from volcanic gases and industrial pollution). Naturally occurring fluoride concentrations in drinking water depend on the type of soil and rock through which the water drains. Generally, concentrations in surface water are relatively low (<0.1–0.5 mg/L), while water from deeper wells may have quite high concentrations (1–10 mg/L) if the rock formations are fluoride-rich.” 2011 ADWG. Health Guideline: 1.5mg/L
Glenn Innes (New South Wales) – Iron
2003-13: Glenn Innes (New South Wales) – Iron 1.65mg/L (max), 0.04mg/L (mean)
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
Glenn Innes (New South Wales) – Aluminium
2003-13: Glenn Innes (New South Wales) – Aluminium 1.17mg/L (max), 0.09mg/L (mean)
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.