Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
Western Pacific Railroad Co.
EPA #: CAD980894679
Congressional District: 02
Other Names: Western Pacific Railroad Roundhouse Facility and Yard
The Third Five-Year Review is scheduled to be completed by September 2013.
On this page
Description and History
NPL Listing History
NPL Status: Deleted
Proposed Date: 10/26/89
Final Date: 08/30/90
Deleted Date: 08/29/01
The 90-acre Western Pacific Railroad Co. site located near Oroville operated as a rail yard from 1920 until 1982. On the eastern portion of the site, in the Fueling Area, the railroad company fueled, repaired, serviced, and cleaned rail cars. Specific activities included sandblasting, welding, cutting, and fabricating. As a result of these activities, waste solvents, oils, grease, and wastewaters containing heavy metals were discharged from the fueling area to an unlined surface impoundment until 1987. This impoundment, which is on the western portion of the site, was cleaned up by the current owner, Union Pacific Railroad Co., in 1989 in response to an order issued by the California Regional Water Quality Control Board (CRWQCB). A concrete tank containing an unknown, oily-like substance also was located on site. Fuel-contaminated soil is located on the site. Four California Water Service Company (CWS) wells are located within three miles of the site. Water from the wells is blended with water from the Feather River to serve the company's 10,000 customers. One of the wells is located on the site and is leased by Union Pacific RR to CWS. The Feather River is located one mile from the site in the direction of surface water runoff and is used for recreational activities.
Contaminants and Risks
- Soil and Sludges
Groundwater on site was contaminated with various volatile organic compounds (VOCs). The surface impoundment was contaminated with heavy metals including arsenic, lead, and chromium. Potential health threats to people included drinking contaminated groundwater or accidentally ingesting contaminated soil. Surface soil in the Fueling Area is contaminated with low levels of polycyclic aromatic hydrocarbons (PAHs).
Who is Involved
This site is being addressed through Federal and potentially responsible parties' actions.
Investigation and Cleanup Activities
The site was addressed in two stages: immediate actions and a long-term remedial phase focusing on cleanup of the entire site.
Immediate Actions: Under State supervision, soils and sludges associated with the surface impoundment were removed and transported to Utah, where they were recycled into asphalt road base. The two 30-gallon concrete sumps were closed; soil samples collected from the surrounding area at the sumps revealed no contamination. The underground oil/waste separator was emptied and backfilled with clean soil. The underground storage tank was removed. An extraction system is pumping and treating a plume of contaminated groundwater near the former underground storage tank.
Entire Site: The site soils in the Fueling Area are contaminated with low levels of polycyclic aromatic hydrocarbons (PAHs), which are chemicals found in fuels, and arsenic. The levels fall within EPA's risk range for industrial land use.
EPA issued a Record of Decision (ROD) in 1997; the selected remedy is excavation and off-site disposal of surface soils in a one acre area. The remedy also includes institutional controls to ensure that future land use remains industrial. EPA issued a Remedial Action Order on June 17, 1998, requiring Union Pacific Railroad Company (UPRR) to implement the selected remedy. In 2001 UPRR negotiated the long-term institutional controls with the State of California Department of Toxic Substances Control.
UPRR installed a groundwater pump-and-treat system in 1994 in order to prevent groundwater contamination from spreading. In early 1997 UPRR installed a second groundwater extraction well with a soil vapor extraction (SVE) unit to remove 1,1-DCE from the groundwater and soil. By the fall of 1997 contaminants in the groundwater dropped below cleanup levels. The groundwater extraction system was turned off in 1999 and the SVE system was turned off in November 2000.
In July 1998 UPRR removed contaminated soil from the fueling area and backfilled the area with clean fill. The contaminated soil was shipped by rail to a landfill in Utah. In March 2001 UPRR filed a deed restriction with the Butte County Recorder which restricts future use of the property to industrial uses only.
Deletion from the National Priorities List: EPA has determined, and the state concurs, that no further response action is appropriate under CERCLA. The site was deleted from the National Priorities List (NPL) on August 29, 2001.
To review the Administrative Record file for the Western Pacific Railroad Co. site, please feel free to call the Superfund Records Center at (415) 536-2000 or check with the site repositories listed below. The Administrative Record is EPA's official collection of data, reports and other information that the EPA considered or relied on in making its decision on the selection of a removal or remedial action for cleaning up the site.
EPA will conduct five-year reviews at the site to ensure that the property is used for commercial and industrial purposes only, as the contamination on site was not cleaned up to allow for residential use. The first five-year review report was released in 2003. The second five-year review report was released in 2008.
In 1989, the State issued a Cleanup and Abatement Order to Union Pacific and Solano Railcar, the potentially responsible parties, requiring them to sample abandoned water supply wells to determine the best way to seal them, to install a water separator to collect runoff from locomotives, and to install equipment to prevent runoff. In 1993, Union Pacific signed an agreement with the EPA to clean up the VOC-contaminated water. In 1994, Union Pacific signed an agreement with the EPA to complete the soil analysis and baseline risk assessment. In 1997 EPA issued a ROD; the selected remedy is excavation of contaminated soil in the Fueling Area in conjunction with long-term institutional controls limiting the use of the property to industrial use only. In 1998 EPA issued a Remedial Action Order requiring Union Pacific Railroad to excavate the contaminated soil and to put some land use restrictions in place.
Cleanup Results to Date
The removal of soils and sludges has virtually eliminated the sources of contamination from the impoundment. The groundwater treatment system cleaned up the VOC plume. The RI/FS indicates that the only other potential threat to human health and the environment is the Fueling Area soil that is contaminated with PAHs. In 1998 contaminated soil was removed from the Fueling Area. That area is now clean enough for commercial and industrial activities to take place. It is not clean enough for residential use.
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
The responsible party at this site was, and continues to be, Union Pacific Railroad.
Documents and Reports
Public Information Repositories
The public information repositories for the site are at the following locations:
Butte County Public Library,
1820 Mitchell Avenue
EPA Site Manager
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
9451 Atkinson Street
Roseville, CA 95747
After Hours (Emergency Response)