2009/15 + 2019/23: Purnim (Victoria) – Chloral Hydrate, Iron, Colour, Turbidity, Total Dissolved Solids

Purnim (Victoria) – Chloral Hydrate

2009/10: Purnim (Victoria) 0.03mg/L [mean 0.03mg/L] [5 samples at 0.03mg/L] Chloral Hydrate

2010/11: Purnim (Victoria) 0.040mg/L Chloral Hydrate (Highest Detection)

2014/15: Purnim (Victoria) 0.029mg/L Chloral Hydrate (Highest Detection)

2004 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.02mg/L

2011 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.1mg/L

Based on health considerations, the concentration of chloral hydrate in drinking water
should not exceed 0.1 mg/L. Action to reduce chloral hydrate is encouraged, but must not compromise disinfection, as non-disinfected water poses significantly greater risk than chloral hydrate. (2011 ADWG)

“Chloral hydrate is a disinfection by-product, arising from chlorination of water containing naturally occurring organic material (NOM). Chloral hydrate has only been detected by Goulburn Valley Water since changing to a new contract testing laboratory in November 2007. The Department of Health is currently conducting a study into the detection of chloral hydrate across Victoria.”

“Trichloroacetaldehyde, cyanogen chloride, chlorophenols were monitored at customer taps (and following disinfection) on a quarterly basis. Trichloroacetaldehyde was also monitored on a weekly basis in Cavendish and Purnim at the request of the Department of Health, as part of a research project on the prevalence of trichloroacetaldehyde in Victorian drinking water supplies. Of the 276 trichloroacetaldehyde samples collected for the year the only locality to exceed the 0.02 mg/L health related guideline value in the 2004 Australian Drinking Water
Guidelines was Purnim. Four of the sixteen samples collected during 2009/10 exceeded 0.02 mg/L. Epichlorohydrin, chlorinated furanonex, chloroketones (chloropropones), chloropicrin were monitored on an annual basis following disinfection at each of Wannon Water’s treatment / disinfection plants.” Wannon Water Water Quality Report 2010

Purnim – Victoria – Iron

2011/12: Purnim (Victoria)  – Iron 0.4mg/L (Highest level only)

2012/13: Purnim (Victoria)  – Iron 0.41mg/L (Highest level only)

2013/14: Purnim (Victoria)  – Iron 0.54mg/L (Highest level only)

2014/15: Purnim (Victoria)  – Iron 0.6mg/L (Highest level only)

2018/19: Purnim (Victoria)  – Iron 0.309mg/L (max), 0.200mg/L (av.)

2019/20: Purnim (Victoria)  – Iron 0.395mg/L (max), 0.247mg/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

Purnim  (Victoria) – Colour

2012/13: Purnim (Victoria) – Colour Apparent 60 HU (Highest Level Only)

2014/15: Purnim (Victoria) – Colour Apparent 62 HU (Highest Level Only)

2020/21: Purnim (Victoria) – Colour 15 HU (max), 8 HU (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…

Purnim – Victoria – Turbidity

2014/15: Purnim (Victoria) – Turbidity 5.7 NTU (Maximum detection during year)

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.

Purnim – Victoria – Total Dissolved Solids

2019/20: Purnim (Victoria) – Total Dissolved Solids 1060mg/L

2022/23: Purnim (Victoria) – Total Dissolved Solids 700mg/L

GUIDELINE

“No specific health guideline value is provided for total dissolved solids (TDS), as there are no
health effects directly attributable to TDS. However for good palatability total dissolved solids
in drinking water should not exceed 600 mg/L.