Investigations and findings

In October 2018, Defence completed investigations into per- and poly- fluoroalkyl substances (PFAS) contamination on and around RAAF Base Williamtown. Defence recognises that PFAS contamination from RAAF Base Williamtown is a significant issue for the local community. Defence is working with the New South Wales (NSW) Government to manage, remediate and monitor PFAS contamination in the area.

The investigations found that PFAS are mostly concentrated in areas where firefighting foams were previously used, stored or disposed. These are called source areas. PFAS in these locations can be found in soil and in water flowing through the source areas. PFAS moves in surface water flowing through drains and creeks or groundwater that flows underground through soil and rock.

Six source areas were found on the base where PFAS concentrations required further study or action:

• Former fire training area
• Lake Cochran
• Sewage treatment plant and associated water ponds
• Trade waste treatment plant
• Fire station and fire training pad / foam testing facility
• Vehicle refuelling facility transport yard.

The demolition of explosive munitions site landfill and north eastern landfill are no longer considered to be a significant source of PFAS.