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Site Description and History
| Site Description and History |
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The Pacific Gas and Electric
Company (PG&E) Topock Compressor Station (Station) compresses natural gas
so it can be transported through pipelines to PG&E's customers in northern
and central California. The Station is located in eastern San Bernardino
County about 12 miles southeast of the city of Needles, California, south
of Interstate 40, and one-half mile west of the Colorado River. The Station
is surrounded by federal land, including the U.S. Fish and Wildlife Service's
Havasu National Wildlife Refuge (HNWR) and lands managed by the U.S. Bureau
of Land Management (BLM) (see the Site Location map to the right). The Topock
Project Site (Site) includes the Station property, as well as the area overlying
the plume, and the properties on which are located the Interim Measures
facilities.
Operations Summary:
- 1951: The Station began operation.
- 1951 - 1985: Hexavalent chromium was used at the Station as an anti-corrosion agent in its cooling towers.
- 1951 - 1968: Cooling tower wastewater was discharged into percolation beds in a dry wash area next to the Station (see Bat Cave Wash photo to the right).
- 1964: PG&E began treating the wastewater to remove hexavalent chromium prior to disposal.
- 1970: PG&E installed an underground injection well to receive treated wastewater.
- 1971: PG&E installed a series of lined evaporation ponds to receive treated wastewater.
- 1971 - 1974: PG&E alternated disposal of the treated wastewater between the injection well and the lined ponds.
- 1974: PG&E began disposal of all wastewater exclusively in the lined ponds.
- 1985: PG&E replaced the chromium-based anti-corrosion additive with a phosphate-based solution.
- 1989: PG&E replaced the original single-lined evaporation ponds with double-lined ponds at a new location, and the original ponds were removed and closed. PG&E's disposal of wastewater from ongoing operations is regulated by the Colorado River Basin Regional Water Quality Control Board (Water Board), a board of the California Environmental Protection Agency (Cal/EPA) (see Corrective Action Overview Timeline below).
- 1996: PG&E entered into a voluntary agreement with
the Department of Toxic Substances
Control (DTSC), a department of the California Environmental Protection
Agency, to investigate the nature and extent and to clean up any contamination
resulting from Station operations. This agreement, the Corrective
Action Consent Agreement (CACA), proscribes that PG&E follows an
investigation and cleanup process governed by a federal law known as
the Resource Conservation and
Recovery Act (RCRA). In compliance with the CACA, data collected
during environmental investigations will be summarized in a three-volume
Final RCRA Facility Investigation/Remedial
Investigation (RFI/RI) Report. The RFI/RI Volume 1 - Site Background
and History was completed in August 2007. A draft of Volume 2 - Groundwater
and Surface Water Characterization Results was submitted to DTSC in
August 2008 and the final version was completed in October 2008. An
addendum to the Volume 2 RFI/RI Report was completed in June 2009. The
final version of Volume 3 - Soil Characterization Results is anticipated
to be completed mid 2011.
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Site Location
map
Bat Cave Wash
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