Question On Notice No. 2421 asked in the Legislative Council on 22 August 2019 by Hon Dr Steve Thomas
Question Directed to the: Minister for Environment
Parliament: 40 Session: 1
Tabled Paper No: 3108-
View tabled paper
Question
I refer to the potential contamination of soil and water by chemicals known as per and poly fluoro alkyl substances (PFAS) found in fire retardant foam, and I ask:
(a) have these substances been discovered in soil or water in Western Australia in any additional locations since the response given to my question on notice No. 1312 asked on 15 May 2018;
(b) if yes to (a), where has it been found and in what concentrations;
(c) have any of these locations been added to the contaminates sites register;
(d) if yes to (c), which sites;
(e) have any sites on which PFAS contamination been recorded had soil removed for processing, reuse or as waste; and
(f) if yes to (e), will the Minister please list each site from which PFAS contaminated soil has been extracted, how much was extracted, and where it was taken?
Answered on 24 September 2019
(a)–(d) Yes. Since my response to Question on Notice No. 1312 on 14 August 2018, per- and polyfluoroalkyl substances (PFAS) have been found in soil, surface water and/or groundwater at a number of additional locations. These locations are grouped into two categories:
1) sites within State jurisdiction being regulated under the Contaminated Sites Act 2003 (CS Act); and
2) locations where PFAS have been identified through ambient monitoring programs.
Sites within State jurisdiction regulated under the CS Act
The attached table [see tabled paper no.#] lists the additional locations regulated under the CS Act and recorded on the contaminated sites electronic register . The table provides the minimum and maximum detected concentrations for the three most commonly tested PFAS [perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS)]. Similar to my previous responses, a brief summary of the management actions required under the CS Act is included. At several of these sites, other contaminants are also present; the classification and management actions consider all types of contaminants at the site.
PFAS identified through ambient monitoring programs
In autumn 2019 the Department of Water and Environmental Regulation (DWER) commenced an investigation of background concentrations of PFAS compounds in surface water and groundwater across the Perth metropolitan area. This has involved testing of 38 surface water bodies (lakes and ponds) and 38 groundwater monitoring bores located on state-owned land.
Results from the autumn 2019 sampling indicate that PFAS are routinely detected at low concentrations in both surface water and groundwater across Perth (PFAS compounds were detected at all of the surface water sampling locations, and at 35 of the groundwater sampling locations). Concentrations of PFOS in surface water ranged from non-detection to 0.044 micrograms per litre, and concentrations of PFOS in groundwater ranged from non-detection to 0.5 micrograms per litre. All concentrations were below the health-based guidance values for non-potable and recreational water uses.
In early 2019, very low levels of PFAS, well below the Australian Drinking Water Guidelines (ADWG) were detected in three Water Corporation production bores located in the western portion of the Esperance town-site. A fourth bore had PFAS detected at a level closer to the ADWG health value (0.07 micrograms per litre), and was taken offline as a precaution Additional sampling of the offline bore identified a maximum concentration of PFOS of 0.13 micrograms per litre. This bore continues to remain offline.
In June and July 2019, DWER tested 20 private and 10 Shire of Esperance bores in the vicinity of the impacted Water Corporation bore, to assess the suitability of groundwater for use for irrigation of parks and private gardens. Concentrations of PFOS detected in private and Shire of Esperance irrigation bores ranged from non-detection to 0.066 micrograms per litre. PFOS and PFHxS concentrations combined in all bores tested by DWER were below the ADWG health value, and well below the health-based guidance value for non-potable use, indicating the water is safe to use for garden irrigation. DWER has informed each bore owner of their individual test results.
(e)–(f) Apart from soil excavated as part of the Forrestfield-Airport Link project (quantities and destinations provided in responses to Questions without Notice numbers 519, 738 and 920), DWER is not aware of any sites from which soil containing PFAS has been taken off-site for processing, reuse or disposal as waste.