2010/11 + 2020/21: Alexandra (Victoria) – Turbidity, Chloral Hydrate

2020/21 – Alexandra (Victoria) – Turbidity

2020/21: Alexandra (Victoria) – Turbidity 5.6NTU (max), 0.1NTU (95th percentile)

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

Alexandra (Victoria) – Chloral Hydrate

Highest Chloral Hydrate levels recorded 2010-2011: 0.048mg/L Alexandra 2010/11.

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

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

“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.” p55 Water Quality Annual Report Goulburn Valley Water.