Odour Report Findings and Next Steps

Published on Tuesday, 21 January 2025 at 9:27:56 AM

In response to community feedback regarding odour concerns in Kalgoorlie-Boulder, the City of Kalgoorlie-Boulder proactively engaged an independent odour specialist to conduct an assessment in October 2024.

An odour report has been received, and the City acknowledges its findings. The report identified multiple contributing sources of the odour near each other, including the City’s South Boulder Wastewater Treatment Plant (SBWWTP). Other industries and businesses identified as contributors have been provided with relevant sections of the report to guide their own actions in addressing the issue.

The City works closely with the Department of Water and Environmental Regulation to investigate odour complaints and to ensure all City facilities meet regulatory requirements. Initial investigations, conducted over a period of time, identified multiple potential sources of odour, making it challenging to pinpoint a single cause in the community.

While other contributors have been identified, the City is committed to addressing issues within its own facilities, with new insights and key operational improvements identified at the Wastewater Treatment Plant.

Several proactive measures to improve the plant’s performance and mitigate impacts on the community have already been implemented. One of these includes improved management of our lagoons by adding lime during the colder months to enhance the pH levels and reduce odour. The City has also been experimenting with mechanical aeration in the lagoons to improve dissolved oxygen levels, further enhancing treatment and reducing odour.

Since July 2024, tanker waste entering the plant has been significantly reduced. While this change was externally initiated, it has positively contributed to reducing odour emissions. Looking ahead, the City will replace the ageing Intermittent Decanted Extended Aeration (IDEA) plant as part of this and the next financial years. The IDEA processing plant combines aeration and sediment in the same tank. The existing plant has been in operation for over two decades and is hindered by design limitations. The new plant, set to be operational within 12 months, will significantly enhance wastewater processing and reduce the potential for odour emissions.

The City thanks all residents who have reported their odour concerns and participated in providing information to the independent odour specialist to assist with his findings. The City acknowledges the impact odours have on residents and remains committed to taking actionable improvements while ensuring the continued reliability of wastewater processing.

A further follow-up report will be provided to Council once the new IDEA plant is operational at the SBWWTP. Residents may continue to report odours via the City’s website which the City will use as part of ongoing monitoring and improvement.

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