2016/17 – Epping Forest (Tasmania) – Chloroacetic Acids, Colour, Turbidity

Epping Forest (Tasmania) – Trichloroacetic Acid, Dichloroacetic Acid

2016/17: Epping Forrest Dichloroacetic Acid 127ug/L (max), 93.75ug/L (mean)

2016/17: Epping Forrest Trichloroacetic Acid 169ug/L (max), 106ug/L (mean)

1/9/17: Epping Forest – Dichloroacetic acid exceedance at 108 ug/L

1/9/17: Epping Forest – Trichloroacetic acid exceedance at 169 ug/L

15/8/17: Epping Forest – Trichloroacetic acid exceedance at 115 ug/L

Australian Guideline Level: Dichloroacetic Acid 0.100mg/L, Trichloroacetic Acid 0.100mg/L

“Chloroacetic acids are produced in drinking water as by-products of the reaction between chlorine and naturally occurring humic and fulvic acids. Concentrations reported overseas range up to 0.16mg/L and are typically about half the chloroform concentration. The chloroacetic acids are used commercially as reagents or intermediates in the preparation of a wide variety of chemicals. Monochloroacetic acid can be used as a pre-emergent herbicide, dichloroacetic acid as an ingredient in some pharmaceutical products, and trichloroacetic acid as a herbicide, soil sterilant and antiseptic.” Australian Drinking Water Guidelines – National Health and Medical Research Council

Epping Forest (Tasmania) – Turbidity

2016/17: Epping Forrest (Tasmania) – Turbidity 14.6 NTU (max), 4.51 NTU (mean)

2017/18: Epping Forest (Tasmania) – Turbidity 9.39 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

Epping Forest (Tasmania) – Colour

2016/17: Epping Forrest (Tasmania) – Colour 18 HU (max), 12.7 HU (mean)

2017/18: Epping Forest (Tasmania) – Colour 32 HU (Highest Level Only)

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…