Since the biofilter installation was completed in December 2025, we’ve been conducting regular odour inspections and actively monitoring the biofilter.

The mulch biofilter, made from locally sourced organic woodchip and plant waste, acts as an odour barrier over the stockpile. It works through both physical absorption and biological processes, providing a surface for microorganisms to break down odours.

The biofilter continues to operate efficiently, with very low to no odour being detected in the immediate area of the sludge stockpile. In January 2026, testing by a specialist odour consultant has confirmed odour removal levels of over 99 per cent.

We’re committed to ongoing operation and maintenance of the biofilter, regularly reviewing its performance. Our monitoring activities include odour sweeps, biofilter checks, and tracking the progress of sludge stabilisation.

Results from sludge stabilisation tracking will help determine when biosolids are ready for beneficial reuse offsite. We expect to remove biosolids in 2027, once the sludge is stabilised.

How to report odour issues to Barwon Water?

If you notice increased odour near your property, please call 1300 656 007 and press 2 for ‘service fault’ (available 24/7). Your feedback is invaluable in helping us respond quickly and coordinate with regulators. While the odour poses no physical risk to human or animal health, we recognise its impact and appreciate your patience and understanding as we continue to address these issues.

Learn more via our previous updates.

If you notice any unusual odours, please let us know so we can investigate promptly.