BOIL WATER ALERT
Lady Baron (Tasmania) – E.coli
August 6 2015: Lady Baron (Tasmania) – E.coli 1 MPN100/mL
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
Lady Baron (Tas) – Trihalomethanes
2021/22: Lady Baron (Tas) Trihalomethanes – 270 µg/L (max)
Trihalomethanes Australian Guideline Level 250μg/L (0.25mg/L)
Why and how are THMs formed?
“When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, THMs are formed. Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds, THMs. They are tasteless and odourless, but harmful and potentially toxic. The quantity of by-products formed is determined by several factors, such as the amount and type of organic material present in water, temperature, pH, chlorine dosage, contact time available for chlorine, and bromide concentration in the water. The organic matter in water mainly consists of a) humic substance, which is the organic portion of soil that remains after prolonged microbial decomposition formed by the decay of leaves, wood, and other vegetable matter; and b) fulvic acid, which is a water soluble substance of low molecular weight that is derived from humus”. Source: https://water.epa.gov/drink/contaminant
Lady Barron (Tasmania) – Aluminium
November 25 2015: Lady Barron (Tasmania) – Aluminium 0.953 mg/L
November 25 2015: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.583 mg/L
December 2 2015: Lady Barron (Tasmania) – Aluminium 0.838 mg/L
December 2 2015: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.595 mg/L
March 2 2016: Lady Barron (Tasmania) – Aluminium 0.705 mg/L
March 2 2016: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.596 mg/L
April 27 2016: Lady Barron (Tasmania) – Aluminium 0.710 mg/L
April 27 2016: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.596 mg/L
May 11 2016: Lady Barron (Tasmania) – Aluminium 0.713 mg/L
May 11 2016: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.679 mg/L
June 1 2016: Lady Barron (Tasmania) – Aluminium 0.704 mg/L
June 1 2016: Lady Barron (Tasmania) – Aluminium (Dissolved) 0.592 mg/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.
Lady Barron (Tasmania) – Colour
March 2 2016: Lady Barron (Tasmania) – Colour Apparent 151 PCU
April 27 2016: Lady Barron (Tasmania) – Colour Apparent 161 PCU
May 11 2016: Lady Barron (Tasmania) – Colour Apparent 146 PCU
June 1 2016: Lady Barron (Tasmania) – Colour Apparent 138 PCU
2016/17: Lady Barron (Tasmania) – Colour 31 HU (max), 14.84 (mean)
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…
Lady Barron – Tasmania – Iron
November 25 2015: Lady Barron (Tasmania) – Iron 5330ug/L
November 25 2015: Lady Barron (Tasmania) – Iron (Dissolved) 2410ug/L
December 2 2015: Lady Barron (Tasmania) – Iron 4740ug/L
December 2 2015: Lady Barron (Tasmania) – Iron (Dissolved) 2440ug/L
March 2 2016: Lady Barron (Tasmania) – Iron 3270ug/L
March 2 2016: Lady Barron (Tasmania) – Iron (Dissolved) 2400ug/L
April 27 2016: Lady Barron (Tasmania) – Iron 3200ug/L
April 27 2016: Lady Barron (Tasmania) – Iron (Dissolved) 2410ug/L
May 11 2016: Lady Barron (Tasmania) – Iron 3080ug/L
May 11 2016: Lady Barron (Tasmania) – Iron (Dissolved) 2580ug/L
June 1 2016: Lady Barron (Tasmania) – Iron 2970ug/L
June 1 2016: Lady Barron (Tasmania) – Iron (Dissolved) 2110ug/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
Lady Barron (Tasmania) – pH (acidic)
Average pH: 2015 July-2016 June: 5.89 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.
Lady Barron – Tasmania – Temperature
February 3 2016: Lady Barron (Tasmania) – Temperature 21.9C
March 2 2016: Lady Barron (Tasmania) – Temperature 22.1C
GUIDELINE
“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
complaints.
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).
Lady Barron (Tasmania) – Chloride
March 2 2016 Lady Barron (Tasmania) Total Chlorides as NaCl 336mg/L
April 27 2016 Lady Barron (Tasmania) Total Chlorides as NaCl 323mg/L
May 11 2016 Lady Barron (Tasmania) Total Chlorides as NaCl 324mg/L
June 1 2016 Lady Barron (Tasmania) Total Chlorides as NaCl 322mg/L
“Chloride is present in natural waters from the dissolution of salt deposits, and contamination from effluent disposal. Sodium chloride is widely used in the production of industrial chemicals such as caustic soda, chlorine, and sodium chlorite and hypochlorite. Potassium chloride is used in the production of fertilisers.
The taste threshold of chloride in water is dependent on the associated cation but is in the range 200–300 mg/L. The chloride content of water can affect corrosion of pipes and fittings. It can also affect the solubility of metal ions.
In surface water, the concentration of chloride is usually less than 100 mg/L and frequently below 10 mg/L. Groundwater can have higher concentrations, particularly if there is salt water intrusion.
Based on aesthetic considerations, the chloride concentration in drinking water should not exceed 250 mg/L.
No health-based guideline value is proposed for chloride.” 2011 Australian Drinking Water Guidelines
Lady Barron – Tasmania – Turbidity
December 16 2015: Lady Barron (Tasmania) – Turbidity 8.91 NTU
February 3 2016: Lady Barron (Tasmania) – Turbidity 6.67 NTU
March 2 2016: Lady Barron (Tasmania) – Turbidity 6.57 NTU
April 6 2016: Lady Barron (Tasmania) – Turbidity 5.31 NTU
April 20 2016: Lady Barron (Tasmania) – Turbidity 14.4 NTU
April 27 2016: Lady Barron (Tasmania) – Turbidity 7.09 NTU
May 4 2016: Lady Barron (Tasmania) – Turbidity 7.08 NTU
June 1 2016: Lady Barron (Tasmania) – Turbidity 5.13 NTU
June 8 2016: Lady Barron (Tasmania) – Turbidity 6.79 NTU
2016/17: Lady Barron (Tasmania) – Turbidity 46.6 NTU (max), 0.86 NTU (mean)
2017/18: Lady Barron (Tasmania) – Turbidity 58 NTU (max) (0.93 NTU (mean)
Lady Barron – Tasmania – Chlorine
25/11/19: Lady Barron (Tasmania) – Chlorine 13.14mg/L
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.
GENERAL DESCRIPTION
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