Third-generation Melbourne market gardener David Wallace is one of dozens of landholders who have been told to stop using water from the Maribyrnong River after toxic chemicals from firefighting foam were detected in runoff from Melbourne Airport.
Mr Wallace’s family has been farming in the Keilor Valley, 15 kilometres north of Melbourne, for 113 years. He spends around $5000 a year on a diversionary licence from Melbourne Water, giving him access to water from the Maribyrnong River.
Now he has been told to stop, after an EPA alert was issued on September 20, following tests for per- and poly-fluoroalkyl chemicals – known as PFAS – at Melbourne Airport and in nearby waterways.
The Department of Health maintains there is no consistent evidence the toxins cause “important” health effects, in contrast to the US EPA, which has concluded they are a human health hazard that – at high-enough levels – can cause immune dysfunction, hormonal interference and certain types of cancer.
Thirty-nine landholders with Melbourne Water diversion licences have been advised to stop using water from the Maribyrnong River as a precautionary measure until further testing could be done.
The EPA has warned people to avoid fishing in the Maribyrnong River upstream of the Calder Freeway to Deep Creek at Bulla, and within all of Arundel Creek. People have been advised not to swim in the waterways and to keep their pets away from the water until further tests were completed.
Testing on water, soil, plants and aquatic life by government authorities will assess any risk to the public posed by chemicals in the waterways.
Until 2010, PFAS were contained in foams used at the airport for firefighting and emergency training.
Aqueous film-forming foams (AFFF) have also been stored in aircraft hangars for deluge systems. The airport is working with tenants to phase out remaining PFAS products.
“I can remember in the ’70s or ’80s there was a lot of foam that did come down the stream,” Mr Wallace said. “We asked ourselves ‘Where is the foam coming from? What is it?’.”
Mr Wallace and his son have abandoned plans to plant pumpkins in their paddocks next year for fear of contamination.
He said it was “frightening,” to think that the chemicals may have been in the water he has used for decades, without his knowledge, and could have persisted in the soil over that time. He is now paying for soil on his property to be tested for PFAS.
Mr Wallace has reduced the amout of Maribyrnong water he used in recent years and was reluctant to grow anything in soil outside his greenhouses.
“Melbourne Water still want to charge for our irrigation entitlement. I think it’s something that should be looked into. I think Melbourne Airport should be held accountable. They should have facilities there to stop any run-off.”
Melbourne Water said the airport had provided an overview of its PFAS investigation on July 30, and briefed Melbourne Water’s chief scientist on the matter a month later.
Diversion customers were notified on September 7 that PFAS had been found in soil and water at the airport, a spokesman said, and then again on September 17, after receiving further information from the airport and preliminary advice from the EPA.
Melbourne Water said it had reminded customers that water sourced under their diversion entitlement was not fit for human consumption, directly or indirectly, without being properly treated.
There is no suggestion that PFAS from the airport has entered drinking water catchments.
Melbourne Airport said it was “really pleased” that the EPA and Melbourne Water were investigating the presence of PFAS in nearby waterways.
Last year the airport tested surface water and groundwater, as well as more than 800 soil samples, for PFAS, a spokesman said.
“These investigations found that PFAS contamination is concentrated in a few locations associated with the historical use of PFAS-containing fire-fighting foams.
“In those locations, concentrations of PFAS in soil were found to exceed current Australian Government Guidelines. These foams were used by aviation fire fighting services, which are provided by Airservices Australia.”
The airport had taken steps to address the presence of PFAS at the airport, the spokesman said, including stockpiling and containing contaminated soil.