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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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  • 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 here (dated April 15, 2014).
  • Final EIR for groundwater cleanup available.
  • Public health information for Hinkley available here.
  • 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?