A plan to remediate the Rural Fire Service site at West Nowra, contaminated by the historical use of fire-fighting foams, or PFAS, is being prepared.
The site, off Albatross Road, is one of six RFS locations across the state identified with contamination.
RFS Executive Director of Infrastructure Bruce McDonald said detailed investigations had found the contamination onsite in the dam and soils but had not spread to neighbouring properties or nearby waterways.
He said soil, groundwater, surface water, drain sediment and surrounding creeks were sampled during a Detailed Site Investigation (DSI) and Human Health and Ecological Risk Assessment (HHERA) on the site.
“Those assessments have been completed, finding none of the samples exceeded the applicable guideline values detailed in the National Environmental Management Plan (NEMP, 2018), with the exception of a water sample taken from the training centre wash water collection dam,” he said.
“The concentrations of PFAS detected pose a low risk to human health, but still need to be cleaned up.”
The dam is on the lowest point of the property, near on the eastern edge of the site, with Mr McDonald indicating if any contamination was to be found on the site it was expected to be at that location.
A total of 69 samples were collected at the site, with Mr McDonald saying the dam’s water level was maintained below the overflow level by evaporation and was not used for any purpose.
“A Dam Management Plan is being developed for the site and is expected to available in the fourth quarter,” Mr McDonald dsaid.
“This plan, in conjunction with the NSW EPA and Shoalhaven City Council will identify practical and sustainable measures to reduce the PFAS in the dam water.”
He said the dam improvement plan included removing all the water from the dam and running it through a series of filters to remove the PFAS.
“With the dam empty we will take more soil samples from the dam itself and determine if the soil has also been contaminated and needs to be removed,” he said.
“It is envisaged, if that is the case, it would only be in the top part of the soil.”
That soil would be removed and under an agreement with the EPA taken to local landfill, where by being widely distributed it would dissipate quite quickly.
“The then filtered and clean water could be replaced,” Mr McDonald said.
RFS discontinued the use of PFAS in firefighting foams in 2007.
“We did not use a lot of foams containing PFAS, especially in training, simply because they were too expensive. They were mainly for fuel fires and we used a different type of foam on bushfires that didn’t contain PFAS,” Mr McDonald said.
It is expected the detailed report will be available in coming months, but starting the actual work might take longer as RFS has to go through the process of engaging specialist decontamination and rehabilitation contractors.