Santa Susana Field Laboratory (SSFL)

Description and History

Background. The Santa Susana Field Laboratory (SSFL) is a 2,850 acre site located in Ventura County, California, approximately 2 miles south of the City of Simi Valley and 30 miles northwest of downtown Los Angeles. The site is divided into four areas which are under different ownership. Boeing owns Areas I, III and IV. The National Aeronautics and Space Administration (NASA) owns and administers Area II and owns 42 acres of Area I. Since 1948, the principal activities in Areas I, II, and III of the SSFL have been large rocket engine research, assembly, and testing by Rocketdyne and NASA. From 1956 to 1988, the Energy Technology and Engineering Center (ETEC), which is located in Area IV was used by Rocketdyne and the Department of Energy (DOE) for nuclear energy research and development. All these past site operations have resulted in soil and groundwater contamination. Primary chemical contaminants include a variety of radionuclides, trichloroethylene (TCE), perchloroethylene (PCE), metals, and petroleum hydrocarbons.

Site Cleanup Status. Cleanup actions of chemical contamination are being conducted by DOE, Boeing and NASA under the direction and oversight of the State of California Department of Toxic Substances Control (DTSC). DTSC is using the Resource Conservation and Recovery Act (RCRA) as its regulatory authority. The extent of chemical contamination has not been fully characterized, but it is estimated that more than 500,000 gallons of TCE is beneath the Site. Radionuclides associated with ETEC nuclear operations include tritium, plutonium-238, plutonium-239, iodine-131, strontium-90, cesium-137, cobalt-60, thorium-228, and uranium-235. Decommission and demolition of ETEC buildings has been conducted by DOE pursuant to the Atomic Energy Act. In accordance with a court order in 2007, DOE stopped its cleanup work in Area IV and is now working on an Environmental Impact Statement (EIS) under the National Environmental Policy Act (NEPA).

EPA’s Role. The 2008 Federal Appropriations Law (HR2764) directed DOE to use a portion of DOE funding for the SSFL site to enter into an interagency agreement with the EPA to conduct a joint comprehensive radioactive site characterization of Area IV of the SSFL in accordance with the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). This has resulted in EPA taking on the following two studies at SSFL:

1. Radiological Background Study. In July 2008, an Inter-Agency Agreement was signed whereby DOE gave EPA $1.5 million to commence a radiological background study for the SSFL site. The purpose of the background study is to determine “ambient or background” levels radiation found in soils not affected by the SSFL site operations. The October 2011 EPA Background Study Report is available for review in the "Investigation and Cleanup" section below and at the SSFL public information repositories listed below.

2. Radiological Study at SSFL Area IV. In June 2009, EPA and DOE amended the Inter-Agency Agreement to provide EPA an additional $40 million to fully fund a radiological study of Area IV and the adjacent northern buffer zone. The majority of the funds ($38.3 million) originate from funding allocated to DOE under the American Recovery and Reinvestment Act of 2009. A map indicating the boundaries of EPA radiological study is provided in a PDF file attached at the top of this website page. EPA's Area IV radiological study consists of the following projects:

Historical Site Assessment. This project consists of EPA's independent review of documents concerning past radiological operations and past spills and releases of radiological materials at SSFL. The goal of this project to is identify the full and complete universe of potential radiological contaminants and locations of where radiological contaminants remaining in Area IV and the northern buffer zone may be located.

Gamma Radiation Scan. This project consists of scanning the accessible areas of the Area IV and the northern buffer zone to identify locations of elevated gamma radiation. A gamma scanning vehicle will be specially designed by EPA and constructed for this project. Any gamma radiation "hot spots" identified by the gamma scan vehicle and other scanning equipment will then be sampled by EPA for full range of potential radiological contaminants.

Testing of Soil, Groundwater and Surface Water. Based on information collected during the Historical Site Assessment and Gamma Scanning, this project consists of testing the soil, groundwater and surface water (i.e. seep water) for a broad range of potential radiological contaminants.

Radiological Technical Advisor during Cleanup of Area IV and the Northern Buffer Zone. Pursuant to administrative order on consent (AOC) between DTSC and DOE, EPA will provide technical assistance on the radiological issues during cleanup in Area IV and the Northern Buffer Zone. Under the AOC, EPA will conduct post cleanup confirmatory radiation assessment in areas where cleanup was performed to verify completion of cleanup. In addition, EPA will verify that backfill/replacement soils do not exceed local background for radioactive components.

National Priorities List and the SSFL site. SSFL is not on EPA’s National Priority List (NPL) and therefore it is not considered a federal “Superfund site”. In November 2007, EPA issued a CERCLA Preliminary Assessment/Site Investigation (PA/SI) report. This report along with other information indicated that SSFL may be eligible for placement on the NPL. In December 2007, EPA sent a letter to the State of California requesting its position in this matter and in January 2009 the State decided to not support to listing SSFL on the NPL. Therefore, the California DTSC will continue in its role as lead regulatory agency at the SSFL site. As lead regulator, DTSC's role includes oversight and approval of risk assessment, clean-up levels, and clean-up actions at the SSFL site. EPA's role shall be limited to providing technical assistance on radiological issues in Area IV and the northern buffer zone as described above.

Contaminants and Risks

Please see http://www.dtsc.ca.gov/SiteCleanup/Santa_Susana_Field_Lab/ for information on chemical contamination at the site.

Please see http://www.etec.energy.gov/char_cleanup/cleanup_index.html for information on radiological contamination at the site.

Who is Involved

As described in the "Description and History" section of this website, this site is being addressed by both State and Federal actions.

The state of California agencies involved at this site include the DTSC and the Regional Water Quality Control Board (RWQCB). DTSC is the overall regulatory lead for the SSFL site. RWQCB is overseeing cleanups of soil contamination in and near site drainages that are regulated under the Clean Water Act.

Boeing, NASA and DOE are conducting investigation and cleanup work under DTSC direction and oversight.

EPA is providing technical assistance on radiological issues in Area IV and the adjacent northern buffer zone.

Cleanup Results to Date

Please see the Investigation and Cleanup Activities section above.

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.

To date, EPA has not officially identified any PRPs at this site.

Community Involvement

Public Meetings: During 2012, U. S. EPA transitioned its Community Involvement program to California’s Department of Toxic Substances Control (DTSC), which will conduct future public engagement activities for the SSFL site. For additional information about DTSC’s community involvement program at the site, please contact Marina Perez, Public Participation Specialist, at (818) 717-6569 or e-mail her at Marina.Perez@dtsc.ca.gov. EPA has placed project documents and reports in the Information Repositories and on EPA’s web site or the DTSC web site: http://www.dtsc.ca.gov/sitecleanup/Santa_Susana_Field_Lab.

Additional Links