Western Water supplies recycled water to both business and residential customers within the region. Each year Western Water transfers around 8,500 megalitres of sewage to our seven recycled water plants. After sewage is treated, most is reused as recycled water with the remaining waste turned into biosolids.
We produce over 7,992ML of recycled water annually. In 2010/11, 51% of recycled water was used by customers, saving 1,488ML of drinking water through substitution.
Recycled Water Plants
Western Water operates seven recycled water plants producing Class A, B and C recycled water. They service Melton, Sunbury, Gisborne, Woodend, Bacchus Marsh, Riddells Creek and Romsey through various methods of supply including farm leases, pipelines and standpipes.
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Recycled Water Treatment
At the recycled water plant, sewage is treated in three stages to obtain Class A, B or C recycled water. Depending on the process used, treatment can take anywhere from eight hours to 40 days. View more information about Recycled Water Classifications.
Primary Stage
The primary stage removes solids as water passes through a screen, preventing large objects such as bottles and plastic bags from entering the rest of the system. Water then passes into a tank where remaining solids sink to the bottom and are removed.
Secondary Stage
In the secondary stage, liquid moves into large aeration tanks where oxygen is pumped in to encourage the growth of micro-organisms. These break down organic matter into simple materials such as water and carbon dioxide. A floating sludge separates from the water during this process and is sent to a sludge digester where it breaks down. This takes about 15 days. The remaining liquid from the secondary tanks is moved to stabilising tanks, where remaining solids settle to the bottom.
Tertiary Stage
Phosphorous is removed during this stage. Phosphorous is a chemical which is often added to detergents. It is harmful to the environment.
Sewage is filtered one last time and remaining solids (biosolids) are removed. The remaining water is disinfected with chlorine. This purified water is then pumped into a shallow holding tank, where sunlight penetrates the water killing remaining bacteria.
Once this process is complete the water is recycled or discharged into the environment.
More Information
For more information on water recycling: