A Western Australian town, Kalgoorlie-Boulder, has taken significant steps to address a mysterious and persistent odour that has plagued its residents since 2023. The local council, in collaboration with odour expert Philippe Najean, has identified the city’s wastewater treatment plant as a primary source of the smell and is now using lime to combat the issue.
Kalgoorlie-Boulder residents have long complained about the strong odour, prompting the city council to engage Najean, director of OPAM Consulting, to investigate. His report pinpointed several odour sources south of Boulder, notably the wastewater treatment facility. Despite initial denials from the council regarding the plant’s role, the findings have led to new measures aimed at mitigating the smell.
Implementing Lime Treatment
With the arrival of winter, the council has begun adding lime to the lagoons at the treatment plant to stabilize pH levels and reduce odour emissions. According to City of Kalgoorlie-Boulder Chief Executive Andrew Brien, colder temperatures and less sunlight can cause pH levels to drop, increasing the risk of odour release.
“Lime is administered to the primary lagoons as needed, based on the city’s proactive daily monitoring of pH levels. When levels fall outside the optimal range, lime is added to rebalance the system and mitigate odour emissions,” Brien explained.
Brien noted a noticeable improvement in odour control this winter compared to the previous year, attributing it to more consistent pH levels and reduced lime dosing frequency.
Additional Measures and Community Involvement
Beyond lime treatment, the council is experimenting with mechanical aeration to enhance oxygen levels in the lagoons. Plans are also underway to replace the decades-old Intermittent Decanted Extended Aeration plant with a new one, further aiming to curb odour emissions.
Local industries and businesses identified in Najean’s report as additional odour sources have been provided with relevant information to develop their own mitigation strategies. This collaborative approach is expected to yield broader improvements in the town’s air quality.
The Expertise Behind the Solution
Philippe Najean, who has nearly 24 years of experience in the odour industry, played a crucial role in diagnosing the problem. Known for his unique approach, Najean relies on his finely tuned sense of smell, which he calibrates every six to 12 months at an olfactometry laboratory.
“My main equipment is my nose because that’s the best equipment you have to measure odours,” Najean told 9news.com.au last year.
Looking Forward
The steps taken by the Kalgoorlie-Boulder council represent a proactive approach to environmental management and community well-being. As the town continues to implement these measures, residents are hopeful for a future with fresher air and a more pleasant living environment.
The council’s efforts, combined with the cooperation of local businesses, highlight a community-driven response to environmental challenges, setting a precedent for other towns facing similar issues. As these initiatives progress, the town will continue to monitor and adjust its strategies to ensure long-term success in odour management.
