An innovative project to open a waste to energy facility which converts liquid waste from local businesses into biogas for renewable energy has been finalised.

The new Melton Recycled Water Plant facility operated by Greater Western Water, makes clever use of the plant’s existing digester tank that normally converts sewage to biosolids but now also treats liquid food waste, processing up to 5,000 litres of waste each year. It is a clever use of technology that is good for the environment and reduces plant operating costs.

Renewable energy from both the facility and a recently constructed 500-kilowatt solar array will provide up to 100% of the Melton plant’s energy needs during peak periods. It will also reduce greenhouse gas emissions by 900 tonnes annually – the equivalent of taking 430 vehicles off the road each year.

For Greater Western Water Project Manager Luke Wilson, the opening of the new facility is the culmination of several years of careful project planning, from conception to scope, design and finally construction.

“Part of my role at Greater Western Water involves maximising the use of our assets and how we can reduce impacts to the environment, while maintaining affordable services for our customers.

“The Melton Recycled Water Plant is a major asset, treating sewage from a fast-growing population in Melbourne’s outer west.”

Greater Western Water Project Manager Luke Wilson

“We were considering how we could leverage the plant to help reduce our environmental impact in the community. We thought ‘is there anything we can do to reduce carbon emissions and extract more value from the resources inherent in organic waste, especially liquid food waste?’”

Planning the project

The water industry has been trialling adding organic waste into anaerobic digesters to generate more renewable energy for some time now. It made sense that Greater Western Water investigate it as well, considering there was digester capacity at the recycled water plant.

A project control group was established to oversee development of the business case. This ensured there was oversight and rigor throughout the planning phase. A range of service offerings were then considered before landing on an innovative solution that allowed the integration of a new waste to energy facility into existing site operations. While ambitious, this made sense from an operational perspective as Greater Western Water’s experienced treatment staff could manage the new facility daily.

Securing funding was the next goal. Part of the $3.3 million project cost was funded with an $800,000 contribution via Sustainability Victoria’s Waste to Energy Infrastructure Fund. This is a Victorian Government initiative that supports investment in waste to energy technologies to assist Victoria in achieving the transition to a low carbon economy.

Design and construction

Waste to energy production is a niche industry. Anaerobic digesters have traditionally only been used to manage sewerage – it is only recently that they have been utilised to manage food waste. For that reason, finding a preferred contractor was critical. The project team knew the project was complex and required close cooperation with the contractor to deliver the facility. A decision was made to go with a design and construct contract. This approach worked well, as the team were able to clearly define the scope from the outset and communicate effectively throughout construction. The team was also fortunate that the contractor was very receptive to the suggested approach and worked collaboratively.

“It was seven years in the making, from 2014 when it was first conceived until March 2021 when the facility was opened to customers. We are so pleased with how the project has gone that we are exploring how the facility can be expanded to receive and process other forms of waste beyond just liquid food waste,” says Luke Wilson.

This article appeared in the Summer 2021 edition of Paradigm Shift magazine. Find out more about the AIPM digital magazine and take a look at the full edition.