Recycled water release at Melton Recycled Water Plant
Melton recycled water release, 4 September 2024
The Environment Protection Authority (EPA) has approved our application to extend the discharge of Class C recycled water into the Werribee River under our operating license (OL000070316) until 1 July 2029.
This extension will help us manage excess storage levels of recycled water at the Melton Recycled Water Plant.
The water we release is fully treated and meets Class C recycled water standards.
To minimise any potential impacts to the Werribee River, we’ve set up a comprehensive testing program conducted by an independent laboratory.
Class C recycled water is safe for agricultural use and livestock drinking, except pigs. It’s not safe for human consumption, swimming or fishing.
Solutions for wastewater management
We’ve pursued many short-term practical solutions for managing excess wastewater, including:
- Maximising on-site and off-site use of recycled water.
- Expanding our storage capacity at the facility and off-site.
- Fast tracking works to divert sewage to the Melbourne Water system, expected to be in operation by November 2024.
- Adding 2 large diesel pumps to transfer recycled water from Melton to Bacchus Marsh. Bacchus Marsh is now at capacity.
We’re also committed to long-term solutions, including:
- Constructing a new bioreactor and implementing several upgrades to further improve our recycled water quality and treatment capacity.
- Investing in the Western Irrigation Network (WIN), which will benefit farmers in the Parwan-Balliang area by supplying significant amounts of recycled water for agricultural use. WIN is a major solution to help manage the increasing volumes of recycled water being produced by the growing population of Melton and Bacchus Marsh.
Releasing recycled water into the Werribee River is a necessary measure to gain time for implementing these upgrades and solutions.
By releasing water in a safe and controlled way, we can also prevent uncontrolled spills that could cause safety issues and damage to our infrastructure.
Why is this happening?
- Bacchus Marsh, Melton and Sunbury are among the fastest growing areas in Victoria, leading to increased volumes of recycled water being produced.
- To manage these increasing volumes of recycled water, we've invested in the Western Irrigation Network (WIN), which uses large quantities of recycled water for agricultural purposes. WIN benefits farmers by supplying a reliable, year-round supply of water for irrigation while reducing recycled water storage levels at the plant.
- However, unforeseen construction delays have prevented WIN from becoming fully operational within the expected timeframe. These delays have resulted in excess unused recycled water at the plant.
- One factor contributing to this delay was the unforeseen discovery of the earless lizard, previously thought to be extinct.
- This rare finding is considered significant, and we're working with the relevant authorities to ensure its protection.
Previous updates
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We’ve started releasing Class C recycled water into the Werribee River under our existing discharge licence (OL000070316) to help manage excess storage levels at the Melton Recycled Water Plant.
This water has been fully treated and exceeds the Environment Protection Authority’s (EPA’s) standards for Class C recycled water.
Our current licence allows for 1100ML per annum. The EPA has also approved a Section 157 which will allow for additional temporary releases of up to 700ML per annum.
This controlled release is necessary to prevent the risk of an uncontrolled spill.
The plant has reached capacity due to construction delays that have impeded our efforts to manage the excess water supply.
During the release, an independent laboratory contractor will take daily samples at nine monitoring points along the waterway to ensure the water quality continues to meet our licence requirements. These points include locations upstream, downstream, and at the discharge point.
The release is expected to last around 90 days, but it won’t occur daily.
While releasing recycled water can sometimes increase the risk of algal blooms it's considered unlikely in this case, due to the cool temperatures.
Class C recycled water is safe for livestock grazing and agricultural use, however it is not safe for human consumption including drinking, swimming and fishing.
We’re extending our release of Class C recycled water into the Werribee River to help manage excess storage levels at the Melton Recycled Water Plant.
This water has been fully treated and meets the Environment Protection Authority’s (EPA’s) standards for Class C recycled water.
Our condition to discharge under our operating license (OL000070316) expired 1 July 2024. We’ve applied to extend this licence condition until 1 July 2030 and this application process is still ongoing.
In May, we shared that the EPA granted approval of an authorisation to temporarily discharge an additional volume under Section 157 of the Environment Protection Act 2017 (see update below).
Due to continued excess water at the plant, we’re currently engaging with the EPA to manage the emergency release volumes.
Extending the release will have minimal impact on Werribee River and will not increase the risk of environmental or human health impacts, as the recycled water quality is compliant with EPA licence requirements.
We’ve pursued many practical, short-term solutions for managing excess wastewater at the plant, including additional storage options, transporting water to other sites, and using the water for local irrigation. No viable options remain, necessitating a controlled release to Werribee River.
This controlled release is a final option and necessary to prevent the risk of an uncontrolled spill which could result in safety issues at our plant and damage to our infrastructure.
During the release, an independent laboratory contractor will take daily samples at nine monitoring points along the waterway to ensure the water quality continues to meet our license requirements. These points include locations upstream, downstream, and at the discharge point.
While releasing recycled water can sometimes increase the risk of algal blooms it's considered unlikely in this case, due to the cool temperatures.
Class C recycled water is safe for livestock grazing and agricultural use, however it is not safe for human consumption including drinking, swimming and fishing.
