Katherine Waste Management Facility
Reporting Period July 1 2020 – June 30 2021
Prepared for Katherine Town Council
EcOz Environmental Consultants
P32: “ In general, PFAS concentrations were higher in the downgradient bores compared to the upgradient bores…”
Groundwater Bores
GWA
May 2017: PFHxS 0.04mg/L, PFOS 0.09mg/L, PFOA 0.06mg/L,
Aug 2020: PFBA 0.03mg/L, PFPeA 0.05mg/L, PFHxA 0.03mg/L, PFHpA 0.01mg/L, TOTAL PFAS 0.12mg/L
26/10/20: PFBA 0.03mg/L, PFPeA 0.05mg/L, PFHxA 0.02mg/L, PFHpA 0.01mg/L, TOTAL PFAS 0.11mg/L
29/4/21: PFPeA 0.04mg/L, TOTAL PFAS 0.04mg/L
GWE
Aug 2020: PFHxS 0.03mg/L, PFOS 0.06mg/L, PFOA 0.01mg/L, Total PFOS+PFHxS 0.09, TOTAL PFAS 0.1mg/L
26/10/20: PFHxS 0.04mg/L, PFOS 0.06mg/L, Total PFOS+PFHxS 0.1, TOTAL PFAS 0.1mg/L
GWBO1
14/9/20: PFBS 0.05mg/L, PFPpS 0.01mg/L, PFPeS 0.04mg/L, PFHxS 0.19mg/L, PFOS 0.24mg/L, PFOA 0.06mg/L, PFBA 0.05mg/L, PFPeA 0.04mg/L, PFHxA 0.06mg/L, PFHpA 0.03mg/L, Total PFOS+PFHxS 0.43, TOTAL PFAS 0.77mg/L
26/10/20: PFBS 0.04mg/L, PFHpS 0.01mg/L, PFPeS 0.03mg/L, PFHxS 0.17mg/L, PFOS 0.23mg/L, PFOA 0.06mg/L, PFBA 0.05mg/L, PFPeA 0.03mg/L, PFHxA 0.06mg/L, PFHpA 0.03mg/L, Total PFOS+PFHxS 0.4mg/L, TOTAL PFAS 0.71mg/L
29/4/21 PFBS 0.01mg/L, PFHpS 0.04mg/L, PFPeS 0.07mg/L, PFHxS 0.58mg/L, PFOS 1.2mg/L, PFOA 0.16mg/L, PFBA 0.06mg/L, PFPeA 0.07mg/L, PFHxA 0.14mg/L, PFHpA 0.07mg/L, Total PFOS+PFHxS 1.8mg/L, TOTAL PFAS 2.5mg/L
GWBO2
14/9/20: PFHxS 0.04mg/L, PFOS 0.04mg/L, PFHxA 0.02mg/L
26/10/20: PFBS 0.02mg/L, PFPeS 0.02mg/L, PFHxS 0.06mg/L, PFOS 0.04mg/L, PFOA 0.02mg/L, PFBA 0.02mg/L, PFHxA 0.04mg/L, PFHpA 0.01mg/L, Total PFOS+PFHxS 0.1, TOTAL PFAS 0.23mg/L
18/5/21: PFBS 0.18mg/L, PFHpS 0.07mg/L, PFPeS 0.14mg/L, PFHxS 0.57mg/L, PFOS 0.69mg/L, PFOA 0.24mg/L, PFBA 0.1mg/L, PFPeA 0.2mg/L, PFHxA 0.36mg/L, PFHpA 0.13mg/L, Total PFOS+PFHxS 1.3, TOTAL PFAS 2.7mg/L
GWB03
18/5/24: PFHxS 0.02mg/L, PFOS 0.03mg/L, Total PFOS+PFHxS 0.05, TOTAL PFAS 0.05mg/L
P37 “Groundwater monitoring results clearly indicate impacts of landfill leachate on groundwater quality. Contaminants elevated in the two downgradient bores (GWB01 and GWB02), compared to the upgradient bores were the major ions (K, Na, Cl and SO4), nitrogen (NH4, NH3), dissolved metals (Mn, Ni and Zn) and a wide mixture of PFAS types.
PFAS concentrations were also recorded in the upgradient bores GWA and GWE, which are drilled deeper into the underlying Tindal Limestone Aquifer. These are likely derived from the regional-scale PFAS contamination from the RAAF Base Tindall, which is dominated by the fire-fighting foam PFAS ingredients PFOS, PFHxS and PFOA (see Figure 31a of the Supplementary Detailed Site Investigation Report, DoD 2018b). The wide mixture of PFAS types seen in the bores downgradient of the landfill are indicative of a landfill-source.”