PG&E Hinkley Groundwater Remediation

Location Hinkley, CA Regulatory Jurisdiction Lahontan Regional Water Quality Control Board

Largest groundwater remediation project in California where PNL is providing management services

PNL Role
PNL performs in a critical and complex role as the Independent Technical Advisor with responsibilities for bridging the technical understanding (and trust/credibility) gap between PG&E and the local Hinkley Community.

Between 1952 and 1966, PG&E used hexavalent chromium, also known as chromium 6, to fight corrosion in its cooling tower waters. The wastewater from the cooling towers was discharged to unlined ponds at the site. Some of the wastewater percolated to the groundwater, resulting in hexavalent chromium pollution. The chromium affects an area of groundwater at least eight miles long and two miles wide. In 2011, the Lahontan Regional Water Quality Control Board ordered PG&E to provide the Hinkley community with an Independent third-party Technical Advisor. In 2012, PNL was selected by the Hinkley Community Advisory Committee to perform in the role of the Independent technical advisor.

In this advisory capacity, PNL has performed the following activities since February 2012:

  • Reviews and comments on all project documentation from PG&E and the Water Board
  • Participated in remediation Environmental Impact Report (EIR), development of the Final Water Board Cleanup and Abatement Order, and the development of USGS Cr(VI) Background Study
  • Hosted and facilitated 60 community meetings
  • Hosted and facilitated 6 community open houses
  • Managed and ran 120 weekly community advisory committee meetings
  • Reviewed and commented on more than 200 major reports
  • Made more than 10 major project presentations to the Water Board
  • Held 300 days of office hours in Hinkley to answer community questions in an informal setting
  • Created and maintained a website with information regarding the Hinkley Remediation project at