2011-2018: Winton (Queensland) – Copper, E.coli, Turbidity, Colour, Iron

2011-2018 – Winton (Queensland) – Copper

2011/18 – Winton – Copper 29mg/L (max), 0.11mg/L (av). (Australian Record high?)

Based on health considerations, the concentration of copper in drinking water should not
exceed 2 mg/L.
Based on aesthetic considerations, the concentration of copper in drinking water should
not exceed 1 mg/L.

Copper is widely distributed in rocks and soils as carbonate and sulfide minerals.

Copper is relatively resistant to corrosion and is used in domestic water supply pipes and fittings. It is also used in the electroplating and chemical industries, and in many household goods. Copper sulfate is used extensively to control the growth of algae in water storages.

Copper is present in uncontaminated surface waters at very low concentrations, usually less than 0.01 mg/L. The concentration can rise substantially when water with a low pH and hardness remains in stagnant contact with copper pipes and fittings. Under these conditions, the concentration of copper can reach 5 mg/L or higher. In one extreme case overseas, a concentration of 22 mg/L was reported.

2011-2018 – Winton (Queensland) – E.coli

2011-2018 Winton 23mpn/100ml (max), 0.17mpn/100ml (av). 7 exceedences
Incident Description: The non-compliance was a detection of E. coli from a routine sample taken on 27/09/2016 at 104 Elderslie Street. 1 cfu E. coli organisms per 100 mL was/were detected when testing was completed on the 28th September, with a disinfection residual of nil (no
disinfection used in Winton Shire Council water supply). Notification was given to Winton Shire Council on the 29th September.
Corrective and Preventative Actions: The reservoir was flushed, and shock dosed with chlorine. Further sampling of the reservoir was completed on the 4th October, testing on the 5th October with no trace of E Coli. All follow up samples were free of E. coli. Testing procedures were reviewed to detect whether the source of E.coli could have been from handling contamination. The same process was used at each of the 6 sites with no other recording of E Coli, handling was unlikely to be the cause. With only one site registering E Coli it is unlikely that it was within the reticulation system. The approach that was taken is to continue testing post
chlorine dosing to see if there were any further occurrences. The subsequent testing came back clear, no further action was taken other than to maintain water sampling and testing regime as per the DWQMP.

“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

2011/18 – Winton (Queensland) – Colour
2011/18: Winton (Queensland) – Colour 19 HU (max), 2.92HU (av.)

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…

2011/18 – Winton (Queensland) – Turbidity

2011/18: Winton – Turbidity 38NTU (max), 1.21NTU (av.)

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

2011/18: Winton (Queensland) Iron

2011/18: Winton  (Queensland) Iron 0.56mg/L (max), 0.08mg/L (av.)

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