2017 – Perry Lakes (Western Australia) – PFOS, PFHxS

2017 Perry Lakes (Western Australia)

Investigations carried out at Perry Lakes and Lake Claremont in 2017 found no PFAS impacts in soil, soil leachate (a measure of potential risk to surface water or groundwater quality) or groundwater up‑gradient of the lakes, or in the surface water of the lakes. However, low‑level PFAS impacts were detected in soil leachate and groundwater at locations immediately downgradient of Perry Lakes. Results for PFOS and PFHxS combined at these locations ranged between 0.01 to 0.12 micrograms per litre in soil leachate (a measure of how much PFOS and PFHxS can leach from the soil in laboratory test conditions) and from 0.01 to 0.03 micrograms per litre1in groundwater. The levels in groundwater were well below the health based guideline value for recreational and non‑potable use (0.7 micrograms per litre). The results indicate that lake sediments may act as a ‘sink’ for diffuse low‑level PFAS in the urban setting, which may

be transported through stormwater run‑off.