Environmental Engineering and Remediation
Site Inspections and Investigations

Site Inspections of Perfluorinated Compounds or Per- and Polyfluoroalkyl Substances (PFAS) Sites

Various U.S. Navy Base Realignment and Closure (BRAC) Installations

GCE was subcontracted to conduct a Site Inspections (SI) to evaluate the presence of perfluorinated compounds (PFCs), or per- and polyfluoroalkyl substances (PFAS) in various environmental media at several Navy BRAC installations. These SIs were performed in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Installation Restoration Program (IRP). All work was conducted following applicable and appropriate Department of Defense (DoD) and/or Department of Navy (DON) guidance and policy for the IRP.

The BRAC Installations included under this subcontract to GCE were:

  • Naval Air Station (NAS) Alameda, CA
  • Naval Station (NS) Treasure Island, CA
  • Mare Island Naval Shipyard (MINS), CA
  • Hunter's Point Naval Shipyard (NSY), CA
  • Naval Air Warfare Center (NAWC) Indianapolis, IN

The objective was to develop and conduct base-wide SIs for known or suspected releases of PFAS at areas of interest (AOIs) recommended for further investigation in the Preliminary Assessments (PAs). The SIs required sampling a variety of media to support an evaluation for the presence of complete exposure pathways to human/ecological receptors via soil, groundwater, or surface water, as needed. The data quality objectives (DQOs) supported the evaluation of PFAS impacts exceeding DoD screening levels, U.S. Environmental Protection Agency (U.S. EPA) Lifetime Health Advisory levels, and/or other promulgated State screening levels, as appropriate. The primary contaminants of potential concern included only perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorobutanesulfonic acid (PFBS) as they were the only analytes with vetted toxicity values at the time the contract was awarded.

The SIs were not intended to detail the vertical and lateral extent of contamination. The performance objective was to obtain regulatory agency and/or Navy approval, as applicable, for SIs and other submitted deliverables. Work elements included: Project Management Support, Scoping, and Meetings; Program Sampling and Analysis Plan (SAP) and Quality Assurance Project Plan (QAPP); Accident Prevention Plan (APP) and Site-Specific Safety and Health Plan (SSHP); Field Activities; and Reporting.

GCE performed the necessary site preparation to adequately support the field investigation methodology outlined in the SAP/QAPP. Field activities were performed at each installation for applicable AOIs as required in the SAP/QAPP/APP/SSHP. Specific field tasks included, but were not limited to:

  • Performed subsurface clearances for intrusive activities.
  • Drilling and installation of temporary wells with pre-pack stainless steel screens as required for each site (where too few or no monitoring wells existed) that included development, lithologic logging, and abandonment after purging and sampling.
  • Collection and analysis of soil, groundwater, and/or surface water samples, as wells as Quality Assurance/Quality Control (QA/QC) samples (e.g., equipment blanks, trip blanks, source water blanks, duplicates, etc.).
  • Recorded all sampling locations using a sub-meter global positioning system (GPS) and/or by tape/compass from known landmarks, streets, benchmarks, and buildings.
  • Determined direction of groundwater flow and measured the depth to water in all wells.
  • Waste characterization sampling and management/disposal of all investigation derived waste (IDW).