Background
Through the first half of 2024, the Department of Water and Environmental Regulation (the department) received a significant increase in the number of odour complaints from the Secret Harbour and Mandurah areas, including Singleton, Lakelands and surrounding suburbs.
Field odour surveys were conducted by officers from the department which identified the activities of several companies in Nambeelup as having the potential to cause or contribute to odour emissions in the community.
Three premises in the Nambeelup area hold licences under Part V of the EP Act which specify operating conditions to be met to mitigate emissions, including odours. Information on the licences is publicly available.
- C-Wise (L8410/2009/2) liquid waste and compost manufacturing and soil blending facility.
- CM Farms (L6932/1988/11) intensive piggery, with a licence expiry date of 26 October 2029.
- Mushroom Exchange (L7210/1997/10), located adjacent to the C-Wise and CM Farms premises, carries out compost manufacturing and soil blending, with a licence expiry date of 27 April 2026.
On 22 February 2024, following departmental investigations, Environmental Protection Notices (EPNs) were issued to two companies in Nambeelup including WA Composts Pty Ltd trading as C-Wise (EPN 202401) and Derby Industries Pty Ltd trading as Craig Mostyn Farms Pty Ltd (CM Farms) (EPN 202402). Non-compliance with the requirements of an EPN is considered a serious offence under the Environmental Protection Act 1986 (EP Act).
C-Wise was directed to:
- take immediate action to reduce the risk of odour emissions from the liquid waste storage and treatment ponds
- conduct investigations into liquid waste storage and treatment ponds at the premises to ensure effective control of odour emissions from the ponds
- engage an odour expert to conduct an odour analysis considering all waste types received at the premises
- provide a report on investigations undertaken to the department including details of any improvements that can be made to operations on the premises to reduce unreasonable odour emissions.
View the C-Wise EPN.
CM Farms was directed to:
- engage a wastewater expert to undertake an investigation into the performance of the wastewater treatment ponds on the premises and provide details of factors that are likely to be contributing to the unreasonable odour emissions from the ponds
- identify any improvements to the wastewater treatment plant and wastewater treatment ponds necessary to reduce the potential for unreasonable odour emissions
- provide a report on investigations undertaken to the department including details of any improvements that can be made to operations on the premises to reduce unreasonable odour emissions.
View the CM Farms EPN.
The department engaged an odour expert to assist with field odour surveys and investigations of all sites in the Nambeelup precinct. The expert provided independent advice to the department on measures required or necessary to quickly mitigate odour emissions from any identified odour sources.
The department also engaged a wastewater expert to support in the identification of the issues and appropriate solutions.
Current situation
The department acknowledges the impacts on the community from odour and continues to take the issue very seriously.
On 25 October 2024, the department amended C-Wise’s licence to include new conditions to support better regulation of odour emissions and to require C-Wise to develop a sludge management plan for the storage, treatment and disposal of sludge from the liquid waste ponds on the premises. The objectives of the sludge management plan are to mitigate odour and leachate emissions associated with pond desludging and sludge use and disposal, while ensuring compliance with the per- and poly-fluoroalkyl substances (PFAS) National Environmental Management Plan (NEMP).
The licence amendment also extended the licence expiry date by 3.5 years to 22 April 2028.
The department is determining whether further regulatory actions are required to mitigate odour emissions from the Nambeelup premises and to resolve odour issues in the area. Odour issues can take some time to fully address, and the department is continuing to work to reduce any impacts being experienced by the community.
The department is grateful for the community reporting the ongoing odour impacts which greatly assists in the investigation and identification of odour sources.
Community members and residents are reminded that it is important to report odour impacts at the time odour is occurring by calling the Pollution Watch Hotline on 1300 784 782 or using the online reporting tool. Please be as specific as you can when describing the odour and the impact it is having on you.
This page will be updated as new information becomes available. If you have any questions relating to this issue, please email info@dwer.wa.gov.au.
