2009 + 2015/18: Whitemark (Tasmania). E.coli, Lead, Iron, pH, Temperature, Chlorine


Whitemark – (Tasmania) – E.coli

March 17 2016: Whitemark (Tasmania) – 3.1 MPN100/mL

April 6 2016: Whitemark (Tasmania) – 1 MPN100/mL

April 27 2016: Whitemark (Tasmania) – 3.1 MPN100/mL

June 8 2016: Whitemark (Tasmania) – 16.6 MPN100/mL

June 21 2016: Whitemark (Tasmania) – 3.1 MPN100/mL

2016/17: Whitemark (Tasmania). 1 E.coli exceedence. E.coli detection of 2 MPN/100mL on 10/04/2017 at WMW51W08 Whitemark / CWS. Site was closely examined and resampled. No indication of compromised water quality. The inappropriate sampling point was relocated.
Resample taken on 12/04/2017 and results all clear

Escherichia coli should not be detected in any 100 mL sample of drinking water. If detected
in drinking water, immediate action should be taken including investigation of potential
sources of faecal contamination.

“Coliforms are Gram-negative, non-spore-forming, rod-shaped bacteria that are capable of aerobic and facultative anaerobic growth in the presence of bile salts or other surface active agents with similar growth-inhibiting properties. They are found in large numbers in the faeces of humans and other warm-blooded animals, but many species also occur in the environment.

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 2011

Whitemark (Tasmania) – Lead

Lead has also breached ADWG’s at Queenstown and Gormanston in south west Tasmania. Breaches occurred three times in Gormanston in 2011 (highest reading 0.0295mg/L) and twice in Queenstown (highest reading 0.0.0118mg/L). In 2009-11, the following Tasmanian communities also had lead readings above the ADWG, Whitemark 0.017mg/L, Pioneer 0.015mg/L & 0.0109mg/L and Avoca 0.0106mg/L.

Whitemark – Tasmania – Iron

March 2 2016: Whitemark (Tasmania) – Iron 502ug/L

April 27 2016: Whitemark (Tasmania) – Iron 458ug/L

May 11 2016: Whitemark (Tasmania) – Iron 409ug/L

June 1 2016: Whitemark (Tasmania) – Iron 357ug/L

March 2 2016: Whitemark (Tasmania) – Iron (Dissolved) 419ug/L

April 27 2016: Whitemark (Tasmania) – Iron (Dissolved) 367ug/L

May 11 2016: Whitemark (Tasmania) – Iron (Dissolved) 338ug/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

Whitemark (Tasmania) – pH (acidic)

Average pH: 2015 December-2016 June: 5.929 pH units

Based on the need to reduce corrosion and encrustation in pipes and fittings, the pH of
drinking water should be between 6.5 and 8.5.

New concrete tanks and cement-mortar lined pipes can significantly increase pH and
a value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in
microbiological quality.

pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

One of the major objectives in controlling pH is to minimise corrosion and encrustation in pipes and fittings. Corrosion can be reduced by the formation of a protective layer of calcium carbonate on the inside of the pipe or fitting, and the formation of this layer is affected by pH, temperature, the availability of calcium (hardness) and carbon dioxide. If the water is too alkaline (above pH 8.5), the rapid deposition and build-up of calcium carbonate that can result may eventually block the pipe.

Whitemark – Tasmania – Temperature

December 16 2015: Whitemark (Tasmania) – Temperature 21C

February 3 2016: Whitemark (Tasmania) – Temperature 21.2C

March 2 2016: Whitemark (Tasmania) – Temperature 22.7C


“No guideline is set due to the impracticality of controlling water temperature.
Drinking water temperatures above 20°C may result in an increase in the number of

Temperature is primarily an aesthetic criterion for drinking water. Generally, cool water is more palatable than warm or cold water. In general, consumers will react to a change in water temperature. Complaints are most frequent when the temperature suddenly increases.

The turbidity and colour of filtered water may be indirectly affected by temperature, as low water temperatures tend to decrease the efficiency of water treatment processes by, for instance, affecting floc formation rates and sedimentation efficiency.

Chemical reaction rates increase with temperature, and this can lead to greater corrosion of pipes and fittings in closed systems. Scale formation in hard waters will also be greater at higher temperatures…

Water temperatures in major Australian reticulated supplies range from 10°C to 30°C. In some long, above-ground pipelines, water temperatures up to 45°C may be experienced…

The effectiveness of chlorine as a disinfectant is influenced by the temperature of the water being dosed. Generally higher temperatures result in more effective disinfection at a particular chlorine dose, but this may be counterbalanced by a more rapid loss of chlorine to the atmosphere (AWWA 1990).

Whitemark – Tasmania – Turbidity

June 8 2016: Whitemark (Tasmania) – Turbidity 16.7 NTU

2016/17: Whitemark (Tasmania) – Turbidity 13.3 NTU (max), 0.51 NTU (mean)

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.

Whitemark (Tasmania) – Chlorine
2017/18: Whitemark (Tasmania) – Chlorine Free Residual 12.23mg/L

Based on health considerations, the guideline value for total chlorine in drinking water is 5 mg/L.

Chlorine dissociates in water to form free chlorine, which consists of aqueous molecular chlorine, hypochlorous acid and hypochlorite ion. Chlorine and hypochlorites are toxic to microorganisms and are used extensively as disinfectants for drinking water supplies. Chlorine is also used to disinfect sewage and wastewater, swimming pool water, in-plant supplies, and industrial cooling water.

Chlorine has an odour threshold in drinking water of about 0.6 mg/L, but some people are particularly sensitive and can detect amounts as low as 0.2 mg/L. Water authorities may need to exceed the odour threshold value of 0.6 mg/L in order to maintain an effective disinfectant residual.

In the food industry, chlorine and hypochlorites are used for general sanitation and for odour control. Large amounts of chlorine are used in the production of industrial and domestic disinfectants and bleaches, and it is used in the synthesis of a large range of chemical compounds.

Free chlorine reacts with ammonia and certain nitrogen compounds to form combined chlorine. With ammonia, chlorine forms chloramines (monochloramine, dichloramine and nitrogen trichloride or trichloramine) (APHA 2012). Chloramines are used for disinfection but are weaker oxidising agents than free chlorine.

Free chlorine and combined chlorine may be present simultaneously (APHA 2012). The term totalchlorine refers to the sum of free chlorine and combined chlorine present in a sample.

Chlorine (Free) ADWG Guideline: 5mg/L (Chlorine in chloraminated supplies 4.1mg/L). Chlorine dissociates in water to form free chlorine, which consists of aqueous molecular chlorine, hypochlorous acid and hypochlorite ion.

Chlorine (Total) ADWG Guideline 5mg/L (chloraminated supplies 4.1mg/L): The term total chlorine refers to the sum of free chlorine and combined chlorine present in a sample