2010/19 – Coolamon (New South Wales) – Colour

Coolamon (New South Wales) – Colour


Anyone connected to a water supply system can be affected by discoloured water. Historically, Goldenfields Water experiences an increase in reports of discoloured water in the Oura and Mount Arthur water supply schemes covering areas such as Junee, West Wyalong, Temora, Coolamon and Ganmain. This is mainly due to the groundwater source having high and fluctuating levels of iron and manganese.

In these areas, service disruptions due to discoloured water can be an isolated issue with most affected customers located at the ‘dead end’ water main or downstream from a water mains failure where discoloured water travels to the customer. These locations may require regular flushing which is varied based on seasonal water demand, age of infrastructure and varying levels of iron and manganese in the groundwater source water.

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…