Per- and poly-fluorinated alkyl substances (PFAS) are a group of chemicals – long used in items such as food packaging, nonstick cookware and firefighting foam – which now find themselves under increasing concerns over environmental and potential health impacts.
In recent years, empirical evidence regarding the toxicity of PFAS chemicals has been brought to light, with human exposure linked to health problems such as immune dysfunction, particular cancers, and fetal developmental issues. A report published earlier this year by the Nordic Council places Europe’s collective health-related costs as a result of PFAS contamination at 50 billion Euros per annum.
In 2018, one of the most widely used PFAS-forming chemicals was listed for restriction and another recommended for a global ban by United Nations officials, under the Stockholm Convention. But, with its “high-persisting” properties the local environment and water supplies could remain contaminated for many years to come.
The Department of Defence began its National Program of PFAS Investigation and Management in 2016. For several decades, the Department has used PFAS chemicals in its firefighting foam, resulting in the widespread contamination of soil and groundwater supplies on its semi-rural training sites.
In accordance with the National Environmental Protection Measure for Site Contamination, the department’s first step was to conduct preliminary, followed by detailed, site investigations; and, where necessary, human health and ecological risk assessments to understand the nature and extent of the contamination.
“We began visualising a number of exposure scenarios, based on likely interactions between natural water systems, surface water creeks etc. to determine the possible migration pathway of the chemicals – and then set out to break those exposure pathways”, said Luke McLeod, Assistant Secretary PFAS Investigation and Management Branch within the Department of Defence, ahead of the PFAS Forum 2019.
“Where necessary we have excavated some sites and undertaken extensive clean-up operations in the local environment and, in particular, drainage systems which can be a source of migration. Our techniques are highly precautionary. We talk about concentration levels in terms of parts to a trillion. No more than 70 out of a trillion ‘parts’ could be contaminated before it exceeds the health based guidance value”.
As well as practical clean-up initiatives, the Department has engaged in extensive community consultation, publishing regular reports to notify and inform the general public of risk assessments and remediation measures; with a view to being “as open and transparent as possible”.
“We have educated local communities on the behaviours and measures they can take to minimise the likelihood of exposure as well as implementing a number of remediation measures to assist local residents”, said Mr. McLeod.
“As an initial temporary measure, we provided local communities with bottled water; but we have since ensured that where required residents are connected to long term solutions including connection to town-water supplies, which we are confident have not been exposed to the chemicals”.
Although the Department has made significant progress in its ongoing operation, the program has not been without challenges. “PFAS has been used since the 1970s and may still be in the environment, not necessarily localised to the area in which it was first deployed”, said Mr. Mcleod.
“It may have migrated from soil to groundwater, been consumed by small fish which are subsequently eaten by birds, which later biodegrade in the soil and leave traces of the chemicals behind. These are the types of scenarios we have had to contend with”.
“Our mission is to do everything we can to ensure that we are adequately fulfilling our role as responsible environmental managers on the commonwealth estate in which we work, and meet the expectations of the community”.
Luke McLeod will deliver a keynote presentation at the PFAS Forum 2019 – where he’ll outline the program and how the Department has effectively deployed funds to optimise the efficacy of its remediation program.