The Santa Susana Field Laboratory (SSFL) is located on approximately 2,850 acres in the Simi Hills in Ventura County, California, roughly 30 miles northwest of downtown Los Angeles. The SSFL facility opened in 1948 when North American Aviation (which later became NAA Rocketdyne Division, then Rockwell International, and, more recently, Boeing) began research, development, and testing of rocket engines, in cooperation with the U.S. Army Air Forces.
SSFL is divided into four Administrative Areas: Area I, II, III, and IV. Most of Area I, Areas III and IV, and two "undeveloped areas" are owned and operated by the Boeing Company. The Department of Energy (DOE) leased a portion of Area IV for energy research. Area II, consisting of 409.5 acres, and a 41.7-acre parcel within Area I are administered by NASA. Both areas were previously used for the development and testing of rocket engines and engine components. The last engine test took place at the Alfa Test Area in 2006.
Prior to rocket engine testing, part of the land was part of the Silvernale Ranch and was used to raise cattle. The property was also the setting for more than 40 movies between the late 1930s and the early 1950s.
During the prehistoric era, the land that constitutes SSFL was used by several Native American groups, including the Chumash, the Fernandeño, the Gabrieleño/Kizh, and the Tataviam. As a result, the SSFL contains significant Native American cultural and archeological resources, including the Burro Flats Site, which is listed on the National Register of Historic Places and the California Register of Historic Places.
NASA used Area II and the liquid oxygen (LOX) production portion of Area I for research and testing of rocket engines and components associated with the Apollo and Space Shuttle Programs. Prior to NASA acquiring the property in 1973, testing was conducted in cooperation with the U.S. Air Force on the Mercury and Gemini missions and for defense purposes.
NASA rocket engine testing took place in Area II at four "test areas" ¬ Alfa, Bravo, Coca, and Delta ¬ each having multiple test stands to static fire the rocket engines. All research and testing activities have ceased, and NASA is now focused on cleaning up chemicals that were released into the environment during testing operations
NASA never conducted nuclear research or used radioactive materials at SSFL. NASA conducted an extensive review of historical documents and completed surveys of all buildings, finding no radiological isotopes or contamination above background levels. A comprehensive radiological survey conducted by the Environmental Protection Agency (EPA) in 2012 found no radiological contamination extending into NASA areas.
Rocket engine testing and supporting activities, such as the production of liquid oxygen, storage of fuels, and engine assembly and cleaning, resulted in the release of chemicals into the environment. The primary contaminants in NASA's portion of SSFL include metals, petroleum products, and solvents such as trichloroethylene (TCE), which was used to clean rocket engines before and after each test.
NASA has been rigorously investigating and, where possible, conducting remediation activities since contamination was found in the late 1980s.
After completion of the Space Shuttle program, NASA concluded it had no further use for SSFL and submitted a "report of excess" to the General Services Administration (GSA) regarding the property in 2009. GSA has conditionally accepted that report pending the completion of NASA's cleanup. NASA will continue to administer the government's portion of SSFL until the property is transferred either to another federal entity or to an entity outside the U.S. government.
The final use of the NASA portion is not yet known, but NASA expects it will ultimately be preserved as open space.
In 2007, NASA, Boeing, DOE, and the Department of Toxic Substances Control (DTSC) signed a Consent Order for Corrective Action that addressed the cleanup of soils and groundwater at SSFL. The 2007 Consent Order requires a risk-based cleanup of groundwater. Risk-based cleanup methods focus cleanup resources on reducing risk and preventing harm, based on the intended future use of a property (such as residential, recreational, industrial, or commercial).
In 2010, NASA entered into an agreement with DTSC, known as the Administrative Order on Consent (AOC), which outlines specific requirements for completing the characterization and cleanup of soils in the NASA-administered areas of SSFL. The AOC requires that soils be cleaned up to “background.” Background refers to the levels of contaminants in the environment prior to releases that require cleanup. A background cleanup at SSFL is defined by the chemical Look-up Table values established by DTSC in 2013.
NASA has completed an extensive soil investigation to determine the nature and extent of soil contamination in NASA areas at SSFL. Through interim soil actions, NASA has already treated or disposed of more than 20,000 cubic yards of soil from those areas. In 2020, NASA released a Record of Decision for Soil Cleanup. NASA is currently working with DTSC to address and resolve the technical issues associated with implementing soil cleanup under the 2010 AOC and the 2013 Look-up Table (LUT values), to guide the path forward and establish a timeline for implementing our final, comprehensive soil cleanup at SSFL.
In the meantime, NASA is preparing for soil cleanup by demolishing obsolete structures on site. Since starting demolition in 2014, NASA has removed nearly 6,000 tons of hazardous waste and recycled over 75,000 tons of clean steel and asphalt, restoring more than 22 acres of land to its natural habitat. The completion of NASA's demolition activities will allow NASA to promptly begin final cleanup activities as soon as the AOC technical issues are resolved and DTSC releases soil decision documents.
After completing extensive groundwater investigations, NASA issued a Record of Decision in 2018 to address groundwater contamination. NASA plans to clean up the groundwater in two phases. Phase 1 focuses on areas with the highest concentrations of trichloroethylene (TCE), a chemical historically used at SSFL for cleaning rocket engines after testing. Phase 2 will address the remaining contamination beneath the NASA areas at SSFL. In January 2026, DTSC approved NASA’s Phase I Corrective Measures Study (CMS) and issued the Final Statement of Basis summarizing the corrective actions NASA will take for groundwater cleanup at SSFL. In coordination with DTSC, NASA is developing the Phase 1 Corrective Measures Implementation (CMI) Plan, which details how NASA will implement the chosen remedy. Once the CMI is approved, NASA can begin Phase 1 of the groundwater cleanup.
Through interim actions and pilot studies, NASA has already treated nearly 540 million gallons of groundwater and removed approximately 6,000 pounds of trichloroethylene (TCE) along with other volatile organic compounds (VOCs) from the underlying bedrock.
In 2014, NASA began demolition activities at SSFL to remove inactive structures and infrastructure, reducing NASA's footprint on the property and preparing the site for final cleanup. In 2024, NASA completed Phase 7 of its demolition with the removal of Coca Test Stand 4, and in 2026, completed Phase 6, the demolition of Coca Test Stand 1. NASA is now preparing for Phase 8, the final planned demolition phase in NASA areas before cleanup.
Phase 8 will involve removing the Coca Control House and the remaining concrete in the spillways and throughout the Coca Test Area. Since demolition started, NASA has removed nearly 6,000 tons of hazardous waste and recycled over 75,000 tons of clean steel and asphalt, restoring more than 22 acres of land to its natural habitat.
In 2020, NASA made the decision to keep the two remaining Alfa Test Stands and the related Alfa control house, and demolish the other structures in the Bravo and Coca Test Areas in accordance with NASA's 2014 Programmatic Agreement.
NASA has made considerable progress over the past decade at the site and is eager to begin final cleanup activities, including completing soil and groundwater investigations, conducting surveys of natural and cultural resources, completing the required environmental review processes, and demolishing obsolete structures.
The SSFL is a complex site that involves multiple parties, extensive regulatory oversight, and community involvement. NASA is working with DTSC under the Resource Conservation and Recovery Act (RCRA) process to develop cleanup plans that will undergo public review prior to DTSC approval.
NASA is taking proactive measures to address stormwater issues, collaborating closely with the Los Angeles Regional Water Quality Control Board and the SSFL Stormwater Expert Panel, an independent blue-ribbon panel that provides technical oversight of surface and stormwater matters. NASA operates a year-round stormwater compliance and management program to support Boeing's efforts to meet National Pollution Discharge Elimination System (NPDES) permit limits at SSFL outfalls.
NASA also develops and implements a stormwater pollution prevention plan (SWPPP) for each action (e.g., demolition, pilot studies) and conducts continuous sampling to ensure stormwater quality meets strict permit standards.
NASA's top priority at SSFL is to protect public health and the environment. The strongest scientific evidence, based on years of investigative work on NASA-administered property at SSFL, shows that the highest concentrations of chemicals are confined to groundwater and soil within the areas where historical operations occurred.
The California DTSC has thoroughly reviewed environmental data on SSFL, including measurements of air, soil, groundwater, surface water, and drinking water, along with 13 health studies, and concluded that there is no offsite contamination from SSFL that would pose a threat to human health or the environment, as documented in its Summary of Health Studies related to the Santa Susana Field Lab (Rocketdyne) site.
The DTSC, along with a team of federal, state, and local agencies, evaluated the impacts of the Woolsey Fire on conditions at the SSFL site and nearby communities by analyzing data from field inspections, physical samples, and air monitoring stations at the SSFL site and in surrounding areas. They concluded that no hazardous materials from SSFL were present in nearby communities after the fire. Their findings are summarized in the DTSC Final Summary Report on the Woolsey Fire. Additionally, the California Department of Public Health, CalEPA, the U.S. EPA, and numerous other federal, state, and local agencies have reviewed the data and confirmed that the fire posed no risks beyond those typically associated with wildfires.
Cultural resources are architectural resources, archaeological resources, objects, structures, districts, traditional cultural properties, cultural landscapes, and Indian Sacred Sites, among other cultural heritage properties.
Within the NASA-administered areas of SSFL, identified cultural resources include the Alfa Test Area Historic District; three individually eligible structures within the district; the Burro Flats Site, which is an archaeological site listed on the National Register; a Traditional Cultural Property; and an Indian Sacred Site.
Multiple laws govern cultural resources, including the National Environmental Policy Act, the National Historic Preservation Act, the Archaeological Protection Act, the American Indian Religious Freedom Act, and others. Additionally, Executive Order 13007 requires federal agencies to accommodate access to and ceremonial use of Indian Sacred Sites by religious practitioners and to avoid adversely affecting the physical integrity of those sites.
NASA takes seriously its role as a steward of the cultural resources within NASA areas and has been working closely with the State Historic Preservation Officer and the Native American community to ensure the protection and preservation of cultural resources located within NASA areas at SSFL.
In 2014, marking the conclusion of the Section 106 consultation process, NASA entered into a Programmatic Agreement (PA) with the California State Historic Preservation Officer (SHPO), the Advisory Council on Historic Preservation (ACHP), and the Santa Ynez Band of Chumash Indians that stipulates measures to be taken to address the adverse effects on cultural resources from NASA's demolition and cleanup activities at SSFL.
Measures include the recordation of the historic test stands, Native American monitoring and oversight during all ground-disturbing field work, an Ethnographic Study documenting the prehistoric and historic native uses of the areas in and around SSFL, and the production and submittal of a Traditional Cultural Property (TCP) nomination to the National Register of Historic Places, among other actions.
NASA continues to engage with Native American representatives and DTSC to develop plans to protect cultural resources during NASA's demolition and cleanup at SSFL.
NASA prioritizes communicating with the public about ongoing environmental investigations and cleanup at SSFL. One of NASA's primary ways to keep the community informed is the NASA SSFL Communications E-List. E-List subscribers receive real-time updates on NASA cleanup activities at SSFL. Updates include notifications of project events and changes to the NASA SSFL website, such as news and new document postings. Subscribe now and stay connected.
NASA personnel occasionally host visitors for tours of the SSFL site. For the safety of the public and for workers, tours of NASA areas are limited due to ongoing field activities. For more information, please contact Lori Manes with NASA SSFL Community Outreach at (818) 806-8834 or lori.manes@nasa.gov.
NASA personnel are involved in meetings with members of the community, regulators, elected officials, and with Boeing and DOE about the SSFL site. NASA attends these meetings, sometimes as a presenter, and at other times to listen and to answer questions. NASA attends meetings of environmental, community, and other interest groups when possible. For more information, please contact Lori Manes with NASA SSFL Community Outreach at (818) 806-8834 or via email at lori.manes@nasa.gov.
Get Acrobat Reader