2008/21 – Raglan (Victoria) – E.coli, Turbidity, Colour, Iron

Raglan (Victoria): E.coli (Regulated Water Supply/Non Potable)
2008/9. Raglan E. coli – 96 orgs / 100 mL. (Max Result) – 23.1% samples no E.coli
2009/10. Raglan E. coli – 35 orgs / 100 mL. (Max Result) – 15.4% samples no E.coli
2010/11. Raglan E. coli – 28 orgs / 100 mL. (Max Result) – 23.1% samples no E.coli
2011/12 E.coli Raglan 72orgs / 100 mL max result 45.8% samples no E.coli
2012/13 Raglan * Ecoli   62orgs / 100 mL max 33.3% samples no E.coli

2013/14 Raglan * E.coli  280orgs / 100 mL max 29.2% samples no E.coli

2014/15 Raglan * Ecoli  110orgs / 100 mL max 25% samples no E.coli

2015/16 Raglan * E.coli 23orgs / 100 mL 69max 26.1%samples no E.coli

2016/17 E.coli Raglan 190orgs / 100 mL max 16.7% samples no E.coli

2018/19 E.coli Raglan 96orgs / 100 mL

2019/20 E.coli Raglan 120orgs/100 mL max

“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

Raglan – Victoria – Turbidity

2008/09: Raglan (Victoria) – Turbidity 18 NTU

2010/11: Raglan (Victoria) – Turbidity 17 NTU

2011/12: Raglan Turbidity 7.5NTU

2012/13: Raglan Turbidity 6.6NTU

2016/17Raglan Turbidity 5.1NTU

2017/18: Raglan (Victoria) – Turbidity 13 NTU (max)

2019/20: Raglan (Victoria) – Turbidity 7.9 NTU (max)

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.

Raglan  (Victoria) – Colour

2008/09: Raglan (Victoria) – Colour 180 HU

2009/10: Raglan (Victoria) – Colour 150 HU

2010/11: Raglan (Victoria) – Colour  190 HU

2011/12 Raglan Colour 140HU

2012/13 Raglan Colour 110HU

2013/14 Raglan Colour 190HU

2014/15 Raglan Colour 110HU

2015/16 Raglan Colour 180HU

2016/17Raglan Colour 190HU

2017/18: Raglan (Victoria) – Colour 140 HU

2018/19: Raglan (Victoria) – Colour 60 HU (max), 24 HU (mean)

2020/21: Raglan (Victoria) – Colour 85HU (max), 45HU (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…

Raglan –  Victoria – Iron

2008/09: Raglan (Victoria)  – Iron 0.62mg/L

2009/10: Raglan (Victoria)  – Iron 0.38mg/L

2010/11: Raglan (Victoria)  – Iron 1mg/L

2011/12 Raglan Iron 0.48mg/L

2014/15: Raglan Iron 0.76mg/L

2016/17: Raglan Iron 0.48mg/L

2017/18: Raglan (Victoria)  – Iron 0.57mg/L

2019/20: Raglan (Victoria) – Iron 0.58mg/L (max)

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