We treat our water before it is supplied to customers.
To ensure the safety of our water supply, we treat and sometimes disinfect the water. We do this because different supply systems have different treatment requirements; for example, according to the catchment area or the chemistry and biology of the water.
Due to the surrounding agricultural and urban activity, drinking water sourced from unprotected catchments requires filtration and disinfection.
Water sourced from Melbourne only requires disinfection, as it is drawn from protected catchments.
Disinfection is an important process that destroys potentially harmful micro-organisms in the water supply. It kills any bacteria or viruses and provides a residual effect to protect the water from recontamination as it travels through the distribution system.
Chlorination is the addition of chlorine as a gas or hypochlorite solution to the water supply to destroy micro-organisms. The water supply in smaller towns responds to chlorine because the pipe network is smaller.
Chloramination is the addition of ammonia to chlorine, which forms chloramines.
Chloramines are less reactive than chlorine alone. The process enables them to travel further into the distribution system, to help maintain disinfection of the water supply. Chloramines are less likely to generate taste and odour issues, compared to chlorine alone.
Acidity is corrected to provide a neutral pH by adding small quantities of lime or soda ash to the water. This ensures the water does not corrode our water mains and also maintains disinfection throughout the system.
Some towns only receive fluoridated water when supplied with water from outside their normal water source. For example, in times of drought, water may come from Melbourne or from other sources.