Western Water’s water treatment processes are determined by a range of factors including the catchment area, the chemistry and biology of the raw water and mandatory requirements such as disinfection and fluoridation.
Drinking water sourced from unprotected catchments (i.e. all local raw water storages available to Western Water) requires filtration and disinfection due to the surrounding agricultural and urban activity. Water sourced from the Melbourne Water Bulk Entitlement is from protected catchments so only requires disinfection.
How do we treat your water supply?
Disinfection is important in order to destroy potentially harmful micro-organisms in the water supply to maintain public health. This process kills any bacteria or viruses in the water and provides a residual disinfection effect to protect the water from recontamination as it travels through the distribution system to customer taps. Chlorine or chloramines are used to disinfect the water supply.
Chlorination is the addition of chlorine as a gas or hypochlorite solution to the water supply and requires minimal contact time to destroy micro-organisms. The water supply in smaller towns responds most effectively to chlorine because the pipe network is smaller.
Chloramination is the addition of ammonia to chlorine, to form chloramines. Chloramines are less reactive than chlorine alone which enables them to travel further into the distribution system to safely maintain disinfection of the water supply. Chloramines are also less likely to generate taste and odour issues, compared to chlorine alone.
The water’s acidity is corrected to provide a neutral pH, by adding small quantities of lime or soda ash. This ensures the water does not corrode our water mains and also maintains disinfection throughout the system.
Your water supply system
To ensure a safe water supply, water authorities including Western Water apply treatment and/or disinfection to water before supplying it to their customers.
In addition to filtration of the water to remove naturally occurring inert particles, Western Water adds measured doses of chemicals to provide you with safe and healthy drinking water. Different supply systems have different treatment requirements.
The type of treatment provided to our various water supply sources are described below. More information can be found in the Water Quality Annual Report.
Water treatment process
Sedimentation, pH correction, filtration, fluoridation and disinfection (chlorination)
Coagulation, pH correction, dissolved air flotation, filtration and disinfection (chlorination)
|Greenvale Reservoir (via Hillside Pump Station)
Melbourne Water bulk entitlement. Pre-fluoridation, pre-chlorination followed by additional secondary disinfection (chlorination)
|Greenvale Reservoir (via Loemans Road Pump Station)
||Melbourne Water bulk entitlement. Pre-Fluoridation, pre-chlorination followed by secondary disinfection (chloramination)|
|Campaspe Reservoir & Reservoir C
||Coagulation, pH correction, dissolved air flotation, filtration and disinfection (chlorination) |
||Microfiltration, pH correction, and disinfection (chloramination)|
|Garden Hut Reservoir
||Coagulation, pH correction, dissolved air flotation, filtration, disinfection (chlorination)|
|Pykes Creek Reservoir
||Coagulation, pH correction, dissolved air flotation, filtration, and disinfection (chlorination)|
In accordance with the requirements set by the Victorian Department of Health, some water supplies have fluoride added for dental health benefits.
The table below highlights the towns within Western Water’s region which receive a fluoridated and non-fluoridated supply.
* These towns 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 brought in from other sources. The levels of fluoride during these times are below what is expected from a normal fluoridated water supply.
More information on fluoridation is available on the Department of Health website.
Most water supplied to Western Water customers has very low hardness. However, some customers receive hard water when supplied with water predominantly sourced from groundwater or from reservoirs with extremely low water storage levels due to drought.
For more information on treatment of your drinking water, contact our Water Quality Team on 1300 650 425 or email email@example.com.