The “vile” stink that has plagued Mandurah residents for months has left scientists from the environmental regulator scratching their heads after an investigation failed to pin down its cause.
Scientists had investigated a piggery and two composting businesses in Nambeelup last year after residents from Madora Bay to Mandurah complained about the smell, describing it as “intolerable” and a “foul smell, like sewerage”.
The spokesperson for the Department of Environment Regulation (DER) said the investigation had widened to include 11 sites with environmental licences including wastewater treatment plants, waste transfer stations, landfills, composting operations and piggeries.
In March, DER undertook three weeks of early morning odour patrols in Lakelands, Stake Hill and Parklands, to gain a better understanding of where the smell could be coming from and impacting weather conditions in real time.
A spokesperson said the department had also launched a six-week scientific odour source identification survey in the Mandurah area, which would conclude in late May.
Last year, Eric Anderson, an 84-year-old Silver Sands resident, said he and his neighbours had been regularly disturbed by the stink.
“It’s a foul smell, like sewerage, and normally comes in about 9pm,” he said.
Mr Anderson said the smell had been so bad at night it had woken him early in the morning.
“I thought our sewerage was broken,” he said.
“It’s not only annoying, it’s unhealthy and it’s just not good enough.”
A DER spokesperson said the department was working with the City of Mandurah, Shire of Murray, industry and the community as the investigation into the odour continues.
Any person wishing to report unreasonable odours should contact DER’s 24-hour Pollution Watch Hotline on 1300 784 782, email pollutionwatch@der.wa.gov.au or submit a report online.
DER has also set up a website to inform residents as the investigation continues.