Groundwater Analytical Results at Brymaroo
This section presents human health and ecological screening assessments for groundwater samples collected in April 2019 at Brymaroo. The groundwater laboratory analytical results are presented in Table T4 in Appendix B and on Figure F18 and Figure F19, Appendix A. The laboratory analytical reports are presented in Appendix F.A summary of PFAS results is presented below.
· Seven of the 13 groundwater samples from monitoring wells at Brymaroo exceeded the adopted human health guideline value for drinking water for sum of PFHxS and PFOS. The maximum sum of PFHxS and PFOS concentration was 16.1 μg/L at MW-G located to the west of the western refuelling pad in the infrastructure area.
· The adopted human health guideline value for drinking water for PFOA was exceeded in one of the groundwater samples. This was the sample from MW-G with a concentration of 0.8 μg/L .
· Three groundwater samples exceeded the adopted human health guideline value for recreational use for sum of PFHxS and PFOS (from MW-G, MW-R and MW-U). There were no exceedances of the adopted human health guideline value for recreational use for PFOA.
· The results have been screened against the 99% level for the protection of freshwater species for PFOS and PFOA due to the potential for these contaminants to bioaccumulate. The PFOS screening level is below the limit of reporting resulting in exceedance of this guideline value by all samples collected where PFOS was detected (total of eight PFOS detections). Since the guideline value is above the limit of reporting, it is not possible to ascertain if the other five groundwater samples exceeded the guideline value.