An update for our local communities about biosolid odours

We want to update our local communities about the odours some people have been noticing from our biosolids facilities.

Biosolids are an unavoidable component of treating sewage, and managing them safely is part of delivering essential sewerage services across our region. Our facilities are purpose‑built and operate under licences issued by the Environment Protection Authority (EPA).

Each year, we use the warmer months to process stored biosolids at our sites in Camperdown, Hamilton and Portland. At times, particularly when the weather is unsettled, this work can cause unpleasant smells.

We know this can be frustrating. Many of us live and work in these same communities, and we understand how odours can affect day‑to‑day life – whether that’s enjoying time at home, working outdoors, or hosting family and community events. We want to be clear that we take these impacts seriously and we don’t dismiss the inconvenience they cause.

Our teams are monitoring conditions closely and adjusting operations wherever we can to reduce odours. We also continue to work with and report to the EPA as required.

There isn’t a simple or quick fix. We know that’s not easy to hear, but we’re committed to doing what we can now, while also working toward long‑term solutions that are fair, sustainable and in the best interests of our region.

What we’re doing right now

We believe being upfront with the community is important.

At the moment, there’s no responsible short‑term option that completely eliminates odour while still meeting safety, environmental and regulatory requirements. That’s not an excuse – it’s a real constraint we’re working within.

To reduce odours as much as possible, we are:

• Adjusting operations based on wind and weather conditions.
• Using a misting system that sprays a natural deodoriser during deliveries and processing.
• Pausing processing during long weekends and major local events.
• Trialling soil capping to help limit odour emissions.

We can temporarily pause processing at one site, but without an alternative in place this would create safety, environmental and service risks elsewhere in the system. Simply shifting the problem from one community to another isn’t a solution.

What’s happening longer term?

In the coming months, the Warrnambool Sewage Treatment Plant upgrade will be operational. This will significantly improve how we manage increasing volumes of domestic and regional industrial waste.

Over time, this will also improve the quality of material processed across our biosolids facilities and help reduce odour impacts.

We’ve also completed detailed work looking at long‑term regional biosolids management options. Our preferred solution is a new regional biosolids processing facility, designed to significantly reduce impacts on communities near existing sites.

Finding the right location, completing planning and approvals, and building a new facility will take time, but this work is underway.

What are biosolids?

During sewage treatment, naturally occurring bacteria break down organic material and help remove harmful bacteria. The treated wastewater is then separated and discharged.

The remaining material, known as sludge, is removed and partially dried. It contains mostly dead micro‑organisms, a small number of active ones, and inert materials like sand.

This material is transported to our biosolids facilities, where it’s dried and composted over several years. Once fully treated, it becomes biosolids that can be safely reused as a soil conditioner, most commonly on agricultural land.