Top of Page (AccessKey T)


Site History

What is the history and background of the Santa Susana Field Laboratory (SSFL)?

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 Simi Hills are bordered on the east by the San Fernando Valley and to the north by Simi Valley. 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. The site is divided into four Administrative Areas — Area I, II, II and IV. Most of Area I and 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 and a small portion of Area I are owned by the U.S. Government and administered by NASA. NASA acquired Area II, consisting of 409.5 acres, from the U.S. Air Force in 1973 and a 41.7-acre parcel in Area I was acquired in 1976.

What did NASA do at SSFL?

SSFL played a significant role in our country’s space program. NASA used Area II to research, develop and test rocket engines associated with the Apollo and Space Shuttle Programs through the 1980s. Some of the historic operations resulted in the release of chemicals into the environment. Currently NASA’s involvement with the SSFL site consists of environmental investigation and remediation activities.

What chemicals have been found in the soil and groundwater how did they get there?

The research, development and testing of rocket engines in NASA-administered areas at SSFL resulted in releases of chemicals into the environment. The most frequently used chemicals in NASA areas were various fuels, oils, liquid oxygen, propellants, Freon and cleaning solvents such as trichloroethylene (TCE). TCE is part of a group of chemicals known as Volatile Organic Compounds (VOCs). Also found at SSFL are items such as paint and transformers containing polychlorinated biphenyls (PCBs). These chemicals made their way into the groundwater located below the ground and into the soil in Area II and the portion of Area I administered by NASA. NASA has been rigorously investigating and conducting remediation activities where possible, since contamination was found in the late 1980s.

What is going to happen to the site after cleanup?

NASA is committed to completing the long-term cleanup of the NASA administered SSFL property and is legally required to complete the cleanup regardless of what happens to the site. Following consideration and review of its current and future needs, NASA concluded it had no further need for the SSFL property. In September 2009, NASA submitted to the General Services Administration (GSA) a "report of excess" regarding the property administered by NASA at SSFL. GSA has conditionally accepted that report pending NASA’s completion of cleanup. Title to the NASA property at SSFL is held by the United States. NASA retains custody and control after the report of excess is delivered to the GSA and until such time as the property is transferred either to another Federal entity or outside the U.S. Government. The final use of the NASA portion is not known at this time but many in the community are hoping the site will ultimately be preserved as open space for public use and remain a vital wildlife corridor in Southern California.

Investigation and Cleanup

What is NASA’s responsibility for cleanup at SSFL?

In August 2007, NASA, Boeing, and DOE signed a Consent Order with the Department of Toxic Substances Control (DTSC) that addressed the cleanup of soils and groundwater at SSFL. Subsequently, on December 6, 2010, NASA and DTSC signed an Administrative Order on Consent for Remedial Action, known as the "2010 AOC," which outlines specific requirements to complete the characterization and cleanup of soils on the NASA-administered areas of SSFL. The 2007 Consent Order requires a risk-based cleanup of groundwater. Determining risk-based cleanup levels involves an extensive characterization process and evaluating actual and potential risks posted by contamination via a risk assessment. Results provide conservative cleanup levels that are protective of human health and the environment. The AOC requires NASA to clean up soils to Look-up Table (LUT) values, also known as a "background" cleanup. The LUT cleanup values required in the AOC are estimated levels of chemicals that were in the soil before any industrial activities took place at SSFL. A cleanup to background levels is one of the most stringent cleanup standards, making SSFL one of the strictest and most comprehensive environmental cleanups in the nation.

How does the AOC cleanup standard compare to a risk-based cleanup standard?

The 2010 AOC requires that the soils on the site be cleaned up to Look up Table (LUT), also known as "background" values. While both the risk-based standard and AOC cleanup requirement would be protective of human health and the environment, the LUT cleanup values required in the AOC are estimated levels of chemicals that were in the soil before any industrial activities took place at SSFL. In contrast, risk-based cleanup levels, are based on human health and ecological risk assessments that evaluate whether and to what extent hazardous chemicals in the environment may pose harm to humans, wildlife, or vegetation. Once a risk assessment is complete, cleanup is done only on the chemicals that pose unacceptable risk. This risk-based approach is one used by EPA and states nationwide and one followed by NASA for other remediation sites. For more information, a white paper analyzing background versus risk-based cleanup scenarios was written in an effort to address public concerns and questions about the difference in the two cleanup standards.

White Paper: Comparative Analysis of Background versus Risk-based Cleanup Scenarios for the Soils at Santa Susana Field Laboratory, Ventura County, California

What is the status of your soil investigation?

NASA has conducted a series of soil investigations including sampling, laboratory analyses, treatability studies and pilot testing in preparation for conducting a comprehensive soil cleanup. The investigation phase, which included 15 areas within Area II and the former LOX plant, as described in the field sampling plans, was completed in early 2016. NASA summarized the results of its investigation in a Final Data Summary Report. NASA’s Final Data Summary Report was submitted in February 2017 and it is currently awaiting finalization by DTSC.

What is the status of your groundwater investigation?

NASA completed its groundwater investigation in 2016. The investigation consisted of extensive sampling groundwater and field work to characterize the nature and extent of the groundwater contamination, understand the groundwater flow direction and rate, and study the impact of bedrock faults and fractures on groundwater flow. Information gathered through the investigation is helping NASA identify the most effective remediation technologies and develop a final cleanup plan for groundwater. A site-wide Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) report, has been developed by the three responsible parties (NASA, Boeing, and DOE). A draft RFI report was submitted to DTSC in May 2017 and is awaiting DTSC comments.

What are NASA’s next steps in the cleanup process?

NASA is eager to move forward with cleanup activities at SSFL. The next immediate milestones are the approval of the Final Data Summary Report (for soils) by DTSC and the completion of the Draft NASA Area RCRA Facility Investigation RFI (for groundwater). NASA is also working with Boeing and DOE to develop a site-wide RFI summary. NASA will issue a Record of Decision (ROD) for cleanup, and then finalize groundwater and soils remedy plans and designs. DTSC has released their Draft Programmatic Environmental Impact Report (PEIR), which examines the cumulative impacts of cleanup by all responsible parties (NASA, DOE, and Boeing). Once a Final PEIR has been certified, DTSC will issue decision documents outlining cleanup remedies and actions they have selected, and NASA will initiate the cleanup phase.

What is NASA doing about stormwater runoff?

NASA has been taking proactive steps to address stormwater, working 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 on surface and storm water issues. NASA has completed three initiatives to enhance Boeing’s efforts to meet National Pollution Discharge Elimination System (NPDES) permit limits at SSFL outfalls: (1) rehabilitating a drainage channel, (2) constructing a stormwater filtration system, and (3) an Interim Source Removal Action (ISRA) removing a total of 11,759 cubic yards of contaminated soil. In addition, NASA has ongoing measures in place, including the strategic placement of straw wattles, riprap, and sandbags, as well as a hydroseeding, to reduce the potential for soil and erosion and enhance revegetation. All of these are designed to reduce sediment discharges and prevent stormwater runoff. NASA continues to conduct sampling to ensure stormwater quality meets strict permit requirements.

Why is the investigation and cleanup taking so long?

The cleanup at SSFL is one of the strictest and most comprehensive environmental cleanups in the nation. In addition to technical challenges associated with geology, it is a complex site that involves multiple parties and extensive oversight as well as community involvement. Every step of investigation and cleanup involves oversight by DTSC and in some instances, other regulatory agencies. Each investigation, work plan, report, and field study requires review and comment by DTSC and, often, by the public before the next step can be taken. NASA continues to cooperate with DTSC to meet the requirements outlined in the 2007 Consent Order and the 2010 AOC and we remain eager to move ahead with final cleanup activities as soon as the regulatory process is complete and the state issues its decision document.

Will NASA use onsite soil treatment options to reduce truck traffic?

The goal is to complete as much onsite soil treatment as possible to reduce the volume of excavated soil requiring offsite disposal and decrease truck traffic. NASA has conducted treatability studies and pilot testing to determine if and what remedial technologies could treat contaminated soil onsite. Based on soil characterization efforts, NASA determined that some chemicals of concern can be treated onsite and some cannot. Most surface soils (the top 2 feet of soil in cleanup areas) are not treatable onsite and will require excavation and offsite disposal. The remaining soils can likely be treated onsite using various in-situ remediation technologies.

How much is this cleanup costing and who is paying?

Although the final cleanup remedies have not yet been determined, NASA currently estimates the total cost of cleaning up the NASA-administered portion of the SSFL site, including a risk-based groundwater cleanup, a soil cleanup to background levels, cultural resources management, and demolition activities, to be more than $400 million. As custodian, NASA is responsible for the cost of cleaning up the portion of the property owned by the U.S. government.


Is there off-site contamination and what is the risk of health effects to nearby residents and visitors?

NASA recognizes concerns by community members regarding public health. Years of investigative work on NASA-administered property at SSFL indicates that the areas with the highest concentrations of chemicals are limited to groundwater located beneath the ground surface and to soil located within the site boundaries. The California Department of Toxic Substances Control (DTSC) conducted extensive reviews of SSFL environmental data, and reviewed and summarized the findings of several health studies and data assessments performed on communities surrounding SSFL. DTSC has found no scientific evidence of offsite contamination from SSFL that would be harmful to human health and the environment, as documented in their Summary of Health Studies related to the Santa Susana Field Lab (Rocketdyne) site.


What are your demolition plans and schedule?

NASA’s overall goal for demolition is to remove obsolete structures in a manner that is safe to onsite workers and the community, and minimizes impacts to the environment. Demolition is occurring in a phased approach and began with the Service Area in 2015. Phase 2, which began in early 2016, included the removal of all remaining structures, pipelines, power lines and other infrastructure outside of the historic districts. A third phase, which began in spring 2017, includes the removal of ancillary and support buildings within the Alfa, Bravo and Coca Test Areas.

Is NASA going to demolish the historic test stands?

Although NASA’s top priority at SSFL is cleanup, we share with many in the community a desire to protect important cultural and historical resources at SSFL. In 2014, NASA entered into a Programmatic Agreement with the California State Historic Preservation Officer, the Federal Advisory Council on Historic Preservation, and the Santa Ynez Band of Chumash Indians. NASA agreed to preserve at least one test stand for historic preservation, provided the AOC cleanup goals could be met. In 2015, NASA received a letter from the Santa Ynez Band of Chumash Indians requesting that NASA defer the demolition of the test stands. In 2017, NASA received a bipartisan letter from Representative Steve Knight signed by several members of the California congressional delegation urging NASA to protect the historic test stands. NASA made the decision to defer demolition of all of the test stands and their associated control houses, unless they pose a risk to safety, human health, or the environment.

How many trucks will be going on and off the site during demolition activities?

NASA understands public concerns about truck traffic to and from the SSFL site and has plans in place to stagger traffic flow during demolition activities. During high-volume traffic hours between 7-9 a.m. and 4-5 p.m., truck departures will be staggered at a minimum of 15-minute intervals. Outside of those times the interval between truck departures could be as low as five minutes, if necessary. During demolition activities, work crews are operating under a work plan that includes dust control and other safety measures, including requiring that all trucks be covered and undergo inspection before leaving the site. Overall, based on previous experience with ISRA and other activities, NASA expects to send off no more than 35 trucks per day during demolition.

How is NASA controlling dust during demolition?

Demolition contractors are required to follow an approved Dust Control Plan to reduce the potential for dust to travel offsite. Some of the dust control measures include enclosing material in barriers, applying water at a sufficient quantity and frequency to prevent wind-driven dust, and not performing loading during high winds or storms. Hydroseeding after work is completed also reduces dust and soil erosion and promotes revegetation. Regular air monitoring is performed via air monitors stationed throughout the worksite. If dust were to reach a certain level in the area, the monitor would sound an alarm to notify workers and demolition activities would be discontinued until levels are reduced.

What happens to hazardous material from demolition activities?

Hazardous materials and wastes from demolition is handled in compliance with the applicable federal, state, and local laws and regulations, including licensing, training of personnel, accumulation limits and times, prevention and response to spills and releases, and reporting and record keeping. Any waste material deemed to be hazardous waste will be loaded directly into secure bins and placed on trucks or trailers for transport to an approved offsite waste facility. All trucks must be covered and undergo inspection before leaving the site, regardless of contents.

How is NASA protecting archaeological resources and the sacred site?

NASA takes seriously its role as a cultural steward and is committed to managing and protecting the resources found at the site. NASA has conducted multiple investigations and surveys of the archaeological resources located in NASA areas at SSFL. NASA is in close communication with tribal authorities through the Sacred Sites Council and the intention is to avoid a disruptive cleanup within archaeological sites. The AOC process provides in the underlying "Agreement in Principle" that Native American artifacts that are formally recognized as cultural resources are exceptions to the background cleanup requirement. If any excavation is required within an archaeological site, NASA will consult with the State Historic Preservation Officer and Native American Tribes to develop and execute a mitigation plan. Professional archaeologists will complete any necessary data recovery, with Native American monitors overseeing all activities.

How is NASA protecting wildlife?

The Santa Susana Field Laboratory contains one of the last remaining wildlife habitat corridors in the Southern California region and NASA is committed to protecting the valuable natural resources found on the site. As part of this effort, NASA has collected and compiled field data, providing a comprehensive account of the varied landscape and biological resources on the property it administers at SSFL. This information is used in the planning and implementation of demolition and other cleanup activities. Before any fieldwork can begin, a certified biologist must conduct a formal biological survey to look for sensitive plant and animal species. In addition, workers are trained to identify federal- and state-listed species. If one of the listed species is observed during operations, activity will halt and a qualified wildlife biologist will be called to the site. If the species is validated as a listed species, the U.S. Fish and Wildlife Service or California Department of Fish and Wildlife will be consulted and additional mitigation measures will be developed.

Community Involvement

How can I stay informed about NASA activities at SSFL?

NASA prioritizes communicating with the public about the ongoing environmental investigations and cleanup at SSFL. One of the primary methods NASA uses to keep the community informed is its NASA SSFL Communications E-List. E-List subscribers receive real-time updates about NASA cleanup activities at SSFL. Updates include notifications about project events and updates to the NASA SSFL website, including news and the posting of new documents. Subscribe now and stay connected.

Can I have a tour of SSFL?

NASA personnel occasionally host community tours of the SSFL site. Tours of NASA areas are limited during demolition and cleanup for the safety of the public and for workers. For more information, please contact Lori Manes with NASA SSFL Community Outreach at (818) 806-8834 or

Can I have a NASA representative present at our group?

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 presenter, and at other times to listen and to answer questions. NASA attends meetings of environmental, community and other interest groups where possible given staffing constraints. For more information please contact Lori Manes with NASA SSFL Community Outreach at (818) 806-8834 or via email at