First stage of WaterNSW investigation into Blue Mountains PFAS completed

The initial investigation identifies three potential sources of contamination: two separate motor vehicle accident sites on the Great Western Highway in 1992 and 2002 near the Medlow Bath township, and the Medlow Bath Rural Fire Brigade station.

Medlow Dam and Greaves Creek Dam, of which Adams Creek is a tributary, will remain disconnected from the Blue Mountains water supply system. The dams will only be returned to the raw water supply network once WaterNSW is confident appropriate permanent mitigation measures are in place.

With these disconnections in place and according to the most recent monitoring results, NSW Health and Sydney Water have advised drinking water in the Blue Mountains meets the existing Australian Drinking Water Guidelines and is safe to drink.

WaterNSW extends its gratitude to the Blue Mountains community who provided time and valuable local knowledge to assist the investigation.

WaterNSW enlisted independent specialist advice in the investigation which included an extensive sampling program, with more than 250 samples taken from 37 different locations.

All accessible tributaries and streams within the watershed of the Great Western Highway were tested. Sediment samples were collected from Medlow Dam and numerous creek beds.

An evaluation of sewerage and stormwater drainage pathways and a conceptual site model were also developed to understand how contaminants may move throughout the catchment.

An analysis of Rural Fire Service, Fire and Rescue NSW and Transport for NSW records and information related to historic activities in the area was also conducted.

The chemical compound signature identified from the sampling at the three identified locations is consistent with the historical use of in Aqueous Fire Fighting Foam (AFFF).

The findings indicate PFAS concentrations are higher in the upper Adams Creek catchment than further downstream in the Medlow/Greaves catchment. This suggests that any contamination may be moving downstream into the Medlow/Greaves catchment via rainfall and surface water runoff, and previous water transfers between dams.

The findings of the WaterNSW investigation have been reviewed by the NSW PFAS Technical Advisory Group and the EPA.

The EPA has recommended that a detailed site investigation should now be undertaken consistent with the National Environment Protection Measure 1999. The detailed investigation undertaken by WaterNSW and supported by the EPA will help inform potential remediation options.

Detailed investigations are likely to involve a number of agencies, with support from the NSW EPA.

To view the most recent PFAS testing results or raw, untreated water in the Blue Mountains visit waternsw.com.au/pfas

Background

While PFAS-based firefighting foams were historically used nationwide and internationally, Fire and Rescue NSW (FRNSW) and the Rural Fire Service (RFS) began phasing out the use of PFAS in 2000 and fully discontinued its use by 2007. Since then, both agencies have adopted alternative firefighting foams and implemented statewide PFAS management programs. FRNSW and RFS will continue to work collaboratively with the EPA, WaterNSW, and other relevant authorities to support ongoing investigations and address any historical contamination.