PFOS and PFOA PA/SI and Additional Monitoring Well Installation, Joint Base Lewis-McChord, WA

Brice, under a JV with AECOM, performed a Phase III of a three-phase Preliminary Assessment/Site Inspection (PA/SI) for Per- and polyfluoroalkyl substances (PFAS) impacts in soil, surface water, and groundwater (GW) at JBLM, a multi-site combined Army/Air Force installation and EPA-regulated site. We performed regulatory compliance, assessments, source investigations and site inspections, and data evaluations/analysis under CERCLA, RCRA, and Washington State Department of Ecology and Department of Health regulations and guidelines.

During Phase III, we installed and developed 12 deep monitoring wells (up to 400 feet below ground surface) using a sonic drilling technique. We used a telescoped, larger casing until reaching the first aquifer, then moved to smaller diameter casing to seal off the upper aquifer from lower aquifer and prevent cross contamination across formations. This process was repeated for the second aquifer to allow penetration into the third aquifer. To ensure that drilling equipment (casing and bits) was properly decontaminated between well locations, an equipment rinsate blank was collected following each installation. Rinsate blanks were analyzed and results documented for PFAS using EPA Method 537.

We also conducted two independent sampling events at the newly installed monitoring wells. Groundwater samples were collected and analyzed by EPA method 537 for PFAS.

Upon completion of fieldwork and analysis, we prepared a PFOS/PFOA Focused PA/SI report that included well logs, development data, and an installation summary; chemical data; chemical data evaluation/analysis; summary of activities; and a discussion of key findings including recommendations for follow-on investigations to characterize the nature and extent of PFAS in groundwater. We also developed an updated Conceptual Site Model as part of the report.

Performance Highlights

• Received “Exceptional” ratings for Management and “Very Good” for Quality, Schedule, Cost Control, and Regulatory Compliance in Final CPARS dated October 2020
• Commended by the client: “The Contractor’s work supported the PA/SI for PFAS at JBLM. Their expertise in the subject was an advantage to the Government. The Contractor did an exceptional job managing the complexities of the scope of work. The Contractor produced very good deliverables on time and on budget… coordinated well with other on-site contractors to mitigate any disruption to on-going activities. This was well done.”