A Nambeelup piggery and neighbouring composting plant have been issued with environmental protection notices after being formally identified as sources of ongoing odours affecting residents in Mandurah’s north and Rockingham’s south.
The Department of Water and Environmental Regulation found organic carbon recycling company C-Wise and intensive piggery CM Farms, operated by Derby Industries Pty Ltd, were the sources of the odour, which has drawn more than 1000 complaints from residents in surrounding suburbs since the start of the year.
Its investigation came after residents lodged 343 complaints to DWER in January. More than 750 have been received this month.
The department said it conducted “extensive field odour surveys” during the day and at night in affected areas — including about 20km away from the businesses in Secret Harbour, Golden Bay and Singleton, as well as Lakelands and nearby Mandurah suburbs, at the end of last week.
It resulted in DWER issuing environmental protection notices to both businesses requiring them to investigate the odour and fix issues causing it “as quickly as possible”.
C-Wise has been ordered to take action to control and reduce the risk of odour emissions from its liquid waste storage and treatment ponds and have an odour expert analyse all types of waste received for processing, while CM Farms is required to have an independent wastewater expert investigate the performance of its wastewater treatment ponds.
DWER is also investigating whether C-Wise and CM Farms have committed any offences through emitting the unpleasant odours.
The businesses have 14 days from being given the notice to provide preliminary investigation results to the department.
CM Farms declined to take responsibility for the stench, with a spokesperson saying the business was “reviewing the requirements of the notice and will undertake all necessary investigations to ascertain whether its activities are contributing to the recent odour emissions in the community”.
“CM Farms seeks to be a good neighbour in every area that it operates and is committed to working with the department to investigate this issue,” the spokesperson said.
C-Wise chief executive Greg Watts said they were “acutely aware” of community concerns about odour and “keen to ensure that we do not cause a nuisance to our neighbours”.
“While organic composting is a business that can create odours, C-Wise handles over 100,000 tonnes of organic waste year-round and every step is taken to minimise odours and it will continue to do so,” Mr Watts said.
“In the last four months, C-Wise has undergone two compliance inspection visits. One in January was specifically targeting odour.
“Both inspections showed that C-Wise complied with its licence.”
According to Mr Watts, DWER’s pollution response team had visited C-Wise six times in the past three months and had “failed to find any significant odours on C-Wise premises”.
“C-Wise has been in discussions with DWER and will continue to work constructively with the department to minimise potential odour emissions,” he said.
Earlier this month, C-Wise lodged a development application with the Shire of Murray to expand the capacity of its 25-year-old facility and eventually replace it with a $42 million upgraded facility.
The company said the new, bigger facility in Keralup would be designed to reduce wafting odours and is expected to process up to 200,000 tonnes of solid organic waste and up to 60,000 tonnes of liquid organic waste into compost each year.
The new facility’s design would include a tank farm, which Mr Watts said would mean less ponds were required and it would “significantly reduce potential odour from the facility”.
He said “every step” of the new facility would be guided by requirements detailed by DWER guidelines to reduce odour emissions.
But the proposal has worried those living nearby, with Stake Hill resident Matthew Richards telling the Mandurah Times earlier this month he and his family would “seriously contemplate selling up and moving” if the plan was approved because of smells that plague his home several times a week.
At the time, DWER said its most recent investigations could not identify the Nambeelup businesses as the source of the odours and findings suggested “natural sources” could be to blame, including Black Swan Lake, Goegrup Lake and sections of the Serpentine River, due to reduced water inflow after a dry winter and hot summer.
The latest announcement from DWER came after Mandurah MLA David Templeman said he had escalated residents’ concerns with Environment Minister Reece Whitby.
Mr Whitby said the department would “get to the bottom of whatever is causing” the odour, which he described as “foul”.
“Complaints about bad odours are always taken seriously and I urge anyone in the Rockingham and Mandurah area who has been affected to make a report to Pollution Watch,” he said.
Last September, CM Farms was fined $10,000 in Mandurah Magistrates Court for contravening its licence conditions under the Environmental Protection Act.
DWER officers visited the site in August 2021 and saw sludge stockpiles from two decommissioned wastewater ponds being stored with no visible hardstand or liner under them, with CM Farms required to store the sludge in an area constructed to minimise emissions into the surrounding environment.