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PG&E Hinkley Chromium Cleanup

Hinkley Compressor Station Chromium Contamination Cleanup

PG&E's natural gas Compressor Station is located approximately two miles southeast of the town of Hinkley and a dozen miles west of Barstow in the Mojave Desert of San Bernardino County. Between 1952 and 1966, PG&E used hexavalent chromium, also known as chromium 6, to fight corrosion in cooling tower water. 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.  Chromium plume maps through time are listed on the bottom of this webpage.

The First Quarter 2014 Monitoring Report shows that chromium has been detected in groundwater in the northern Hinkley Valley and in theHarper Dry Lake Valley out to the Grasshopper Road area.  The chromium plume is undefined in some areas to the maximum background levels of 3.1 ppb hexavalent chromium and 3.2 ppb total chromium. The Water Board has required PG&E to submit workplans to further delineate the plume in groundwater. PG&E has compiled with these requirements and Water Board staff is evaluating the most recent workplan.

The next monitoring report and chromium plume map is due at the end of July 2014.

PG&E is under orders from the Lahontan Water Board to stop plume expansion and clean up the chromium plume. Monthly monitoring reports by PG&E demonstrate that the chromium plume is currently being contained south of Thompson Road.  Plume containment north of Thompson Road will be required once the Water Board adopts a new cleanup and abatement order later in 2014.

Below are certain documents related to some of these corrective actions. All documents associated with the project are available at the Lahontan Water Board office in Victorville and on the State Water Board’s database called Geotracker at http://geotracker.waterboards.ca.gov/.

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  • New! Water Board's staff presentation of the February 26, 2015 Cleanup and Abatement Order Public Meeting

  • New! Proposed Cleanup and Abatement Order - available for review, including references (added 2/5/15)
    • Request for Comments
      • How to submit comments by eMail, U.S.Postal, or FAX:
        • eMail: RB6enfproceed@waterboards.ca.gov
        • US Mail:
          Lahontan Water Board - Attn: Sue Genera
          2501 Lake Tahoe Blvd.
          South Lake Tahoe, CA 96150
        • FAX: (530) 544-2271 - Attn: Sue Genera
        • NOTE: Please include in the subject line of all submittals: "Pacific Gas and Electric Company CAO Hearing"
  • Notice of Applicability to Conduct Bioreactor Pilot Test, dated Dec 05, 2014

  • The grid book format of the First Quarter 2015 chromium plume map is now available for viewing and comment. The new format is a PDF that contains close-ups of the third quarter 2014 chromium plume map, arranged in a grid format. The index to the grids is on page 1 of the PDF.

    See below for information on navigating the maps:

    • The new format is a PDF that contains close-ups of the first quarter 2015 chromium plume map, arranged in a grid format. The index to the grids is on page 1 of the PDF. 
    • To view a close-up map of the plume, click on the map number in your grid of interest (for example, click on “MAP 01” to view the farthest north plume map close-up).  To return to the map grid index (page 1 of the PDF), you may either:
      • Use the scroll bar on the right side of the page to scroll back up to the page 1.
      • Enter page 1 in the tool bar at the top of the page and hit return/enter on your computer keyboard.
      • Use the arrows at the top of the page to go back up to page 1.
    We are interested to hear your feedback on the new format.  This format will not replace the plume maps we currently post at the bottom of this webpage (sized for printing on typical household printers), but would be an additional way to view the map. Email any comments or suggestions to Anne.Holden@waterboards.ca.gov

  • Executive Officer's response to public request to not use new Cr6 MCL for replacement water.

  • On April 15, 2014, the California Department of Public Health (CDPH) announced it has submitted a first-in-the-nation drinking water standard for hexavalent chromium (chromium-6) to the Office of Administrative Law (OAL). The proposed hexavalent chromium drinking water standard, also called a Maximum Contaminant Level, is 10 parts per billion. The final proposed regulation will take effect after it has been reviewed and approved by OAL in compliance with the Administrative Procedures Act. This review can take up to 30 working days to complete. Once approved, the regulation is then filed with the Secretary of State and will become effective the first day of the following quarter.
    • For more information, please go to the CDPH webpage with the news release (dated April 15, 2014).
  • Final EIR for Groundwater Cleanup

  • Public Health Information for Hinkley

Water Board Orders

Investigative Orders

Cleanup Orders

Discharge Permits

Public Health Information

Other Documents

Chromium Background Study

PG&E Feasibility Study

Map of Chromium Plume

Questions or Comments about the Hinkley Project?