The 2,850-acre Santa Susana Field Laboratory straddles the remote Simi Hills at the border of Los Angeles and Ventura counties between Chatsworth and Simi Valley in the Santa Susana Mountains about 30 miles from downtown Los Angeles.

The Santa Susana Field Lab is located within a vital habitat linkage that connects the Santa Susana Mountains with the inland Sierra Madre Mountains to the Santa Monica Mountains to the Pacific Coast. It has many culturally-significant sites related to historic use by Native Americans, and a portion of the site is included in the National Register of Historic Places. The field lab was the proving ground for rocket engines that launched America into space and helped win the Cold War. The American Institute of Aeronautics and Astronautics identifies it as a historic aerospace site. It is a unique part of the cultural, environmental and technological fabric of Simi Valley, California and the United States.

The site was historically used to test rocket engines for NASA and the military, and to perform non-military nuclear energy research at Department of Energy’s (DOE) Energy Technology Engineering Center (ETEC), for example, leading-edge nuclear power, solar and energy-efficiency technology development.

The Santa Susana Field Lab’s 2,850 acres are divided into four administrative areas. Boeing acquired 2,398 acres from Rocketdyne in 1996 when it purchased Rockwell's aerospace and defense unit. The Department of Energy (DOE) owns several buildings on the 90 acres of Boeing property it leased and the U.S. Government owns 452 acres that are administered by the National Aeronautics and Space Administration (NASA).

Santa Susana, CA is a vast hilltop natural area dominated by sandstone cliffs featuring oak woodlands, scrub and meadows, with valley and mountain vistas. Plant and animal species thrive at the Santa Susana Field Lab, including deer, bobcats, coyotes, cougars and raptors. A few decommissioned rocket engine test stands and other buildings still dot the landscape. Nearly 90% of historical buildings have been removed as operational activity at the Department of Energy's Energy Technology Engineering Center was phased out in 1988 and rocket engine testing ended in 2006. Environmental and community groups and universities use the land for environmental research, restoration and recreation. Boeing hosts frequent bus tours and guided hikes to share the Santa Susana’s historical significance and cleanup progress.

The conservation easement ensures the preservation and protection of the unique and critical Simi Hills habitat, cultural resources and open space within nearly 2,400 acres of land that Boeing owns at Santa Susana. It is a legally enforceable property restriction that forever prohibits development or use of the land for residential or agricultural purposes. The land’s future as open space habitat will preserve the land as a wildlife corridor, will benefit local plants and animals (many of which are protected) and will preserve the many cultural resources. The conservation easement memorializes Boeing’s commitment for more than ten years to preserve the Boeing-owned property at the Santa Susana Field Laboratory as open space to protect vital wildlife habitat and honor the land's Native American history.

North American Land Trust (NALT) is a respected, longstanding, experienced land trust that has protected 120,000+ acres and completed over 500 projects in 20 states since 1992. For more information about NALT, visit their website here.

As the holder of the conservation easement, North American Land Trust (NALT) monitors activities at the Santa Susana Field Laboratory to ensure the prevention of development and preservation of natural and cultural resources. NALT also has the authority to enforce the land use restrictions in court.

The conservation easement does not affect the responsibility of Boeing, the Department of Energy or NASA to fulfill their respective cleanup requirements. It ensures there is no confusion about the future use of the Santa Susana Field Laboratory property. Future land use is critical in determining the level of cleanup necessary to protect human health and the environment. The conservation easement legally secures the future of the Simi Valley site as open space habitat. It ensures that, regardless of zoning or the desires of any future land owner, the site will never be used for residential or agricultural purposes. We remain committed to completing a cleanup that fully protects human health and the environment, consistent with the future use of the Santa Susana, CA property as open space habitat.

The conservation easement provides certainty that the only legally permitted future use of nearly 2,400 acres of the Santa Susana Field Lab, now and forever, is open space habitat. The Environmental Impact Report (EIR) should only consider cleanup scenarios consistent with that future use.

The Santa Susana Field Laboratory was at the center of nuclear energy research efforts after World War II to progress space exploration and protect the United States during the Cold War. In connection with these operations, chemicals were used and released into the soil and groundwater.

Boeing has conducted interim cleanup measures at Santa Susana while building the scientific basis for cleanup pending final regulatory approval. Boeing has removed or treated 45,000 cubic yards of soil; analyzed 38,000+ soil and groundwater samples; drilled 260 groundwater monitoring and extraction wells; and dismantled more than 300 structures. In addition, Boeing has:

• Installed a state-of-the-art groundwater treatment system;
• Built stormwater containment and filtration systems designed in consultation with a panel of stormwater experts to meet water quality standards that in many cases are stricter than drinking water standards (although there is no human water consumption)
• Restored 900 acres of land.

In 2007, Boeing, NASA and the DOE signed a comprehensive cleanup agreement (“2007 consent order”) with the Department of Toxic Substances Control (DTSC). Boeing is committed to completing a cleanup of the Santa Susana Field Laboratory that is fully protective of both human health and the environment, consistent with the field lab’s future as open space habitat. Boeing continues to meet all of its obligations to implement the 2007 consent order. Here are key steps in the process:

• The DTSC issues a certified, final site-wide Programmatic Environmental Impact Report (EIR)
• DTSC approves the investigation reports previously submitted by Boeing
• Boeing is preparing risk assessment reports for DTSC approval
• When risk assessment is approved, Boeing will prepare a corrective measure study for DTSC approval
• When corrective measure study is approved and finalized, DTSC will issue a statement of basis outlining the final cleanup plan
• Boeing continues long-term groundwater cleanup and monitoring.
• Boeing completes soil cleanup.

Boeing secured a conservation easement that permanently preserves nearly 2,400 acres of Boeing-owned land at Santa Susana as open space habitat. After the cleanup, Santa Susana, CA will continue to be a place where Santa Susana mountain lions roam free, cultural artifacts remain undisturbed and oak woodlands have the opportunity to thrive.

Yes. We remain committed to a cleanup of the Santa Susana Field Laboratory that is fully protective of human health and the environment, consistent with the land’s future use as open space habitat. Our cleanup will protect everyone who visits Santa Susana for recreational purposes and our neighbors in the surrounding community, as well as preserve unique wildlife habitat and protect important Native American cultural resources.

Boeing recorded a conservation easement that permanently preserves nearly 2,400 acres of Boeing-owned land at the Santa Susana Field Laboratory as open space habitat. This easement ensures there will never be residential or agricultural development of the Simi Hills site.

Based on extensive data collected over decades, there are no levels of contaminants from Santa Susana that would pose a risk for off-site gardens or for residents using those gardens now, and in the future. In an April 2013 letter to the Mayor of Simi Valley, the DTSC stated, "To date we have not found evidence of off-site contamination from SSFL that would pose a risk to human health or the environment."

The reference in Boeing’s report submitted to DTSC that included an estimate for a lifetime Simi Valley cancer risk of one in three is a hypothetical risk prior to cleanup and is primarily attributable to naturally occurring arsenic. The hypothetical risk following cleanup at this location will be 1 in 1 million or less, a point clearly described in Boeing’s report. This calculation is just one among many that are considered in assessing the site and setting the ultimate cleanup level, and it is misleading to focus just on this calculation. The most important fact for the public to understand is that Boeing remains committed to completing a cleanup that is fully protective of both human health and the environment, consistent with the land’s future use as open space habitat.

With regard to the risk calculation referenced above, there are two critical points that must be understood to properly interpret this calculation and comprehend what it means, and what it doesn’t mean.

Assumption #1: The calculation assumes that no cleanup will ever be done. Fact: Boeing will perform a cleanup that is fully protective of human health and the environment, consistent with the land’s future use as open space habitat.

Assumption #2: The calculation assumes that a person will live on the site and consume produce from a backyard garden. Fact: No one will ever live on Boeing’s portion of Santa Susana in the Simi Hills. North American Land Trust holds a conservation easement that permanently preserves nearly 2,400 acres of Boeing-owned land at Santa Susana as open space habitat.

Future land use at the Santa Susana Field Laboratory is controlled by the 2017 conservation easement, not zoning. Under the conservation easement, no agricultural use for human consumption will ever occur on the nearly 2,400 acres at Boeing Santa Susana.

The Environmental Protection Agency defines perchlorate as a chemical compound commonly used in solid rocket propellants, munitions, fireworks, vehicle airbags, matches, fertilizers and signal flares. It also occurs naturally in soil, particularly in arid regions like the southwestern United States found in the Santa Susana Mountains.

Yes. Perchlorate was used in solid rocket motor research in two locations onsite at the field lab; approximately 95% of the rocket engine testing performed at Santa Susana was on liquid-fueled rocket engines without perchlorate.

Perchlorate was discovered in soil and groundwater at the Santa Susana Field Laboratory, consistent with the controlled areas where small rockets were previously tested and a former hazardous waste disposal site. Perchlorate related to activities at Santa Susana was not detected in any of the groundwater, surface water, sediment or soil samples collected at the Simi Valley site.

A perchlorate remediation was performed between 2004 and 2007 at the field lab. Approximately 15,500 cubic yards of soil was excavated and treated onsite, using a treatment approach approved by California Department of Toxic Substances Control (DTSC) and the Los Angeles Regional Water Quality Control Board (Regional Board). Boeing is also pumping and treating groundwater from several areas onsite where groundwater was impacted by historical site operations, including where perchlorate is detected.

No. There is no evidence that the perchlorate detected in Simi Valley wells is related to past operations at Santa Susana. This conclusion is based on a comprehensive study completed by the Army Corps of Engineers in 2007 and numerous other investigation reports and studies.

In the early 2000s, perchlorate was detected in surface soil at the site of the proposed Dayton Canyon development located in West Hills. Although perchlorate was not detected again in that location, an investigation was conducted in connection with DTSC and the Regional Board regarding the potential for perchlorate to move from Santa Susana to the Dayton Canyon development site. Hundreds of soil, sediment, groundwater and surface water samples were collected adjacent to the known use areas at Santa Susana, including drainage areas leading from Santa Susana to the Dayton Canyon site. No evidence of perchlorate was found in any of the offsite sample locations and DTSC released the area for residential development in 2008.

No, the California wildfires did not affect air quality beyond typical smoke associated with fires of this nature. Data collected from Boeing air monitoring stations during the Simi Valley fire confirm that no man-made radionuclides were detected. The data, evaluated by an independent, State-certified laboratory, were consistent with any forest or brush fire where increased airborne particulate matter from smoke and fire is present. Only naturally-occurring radioactive material (NORM) was detected in the samples collected. The levels of NORM were well below regulatory standards for airborne radionuclides and well below general background levels in the United States, which are considered safe by the Nuclear Regulatory Commission (NRC). See “Boeing’s Radiological Air Monitoring Data Associated with the Woolsey Fire” here.

No, the Santa Susana Field Laboratory site does not have dangerous levels of radioactivity. The U.S. EPA completed a $42 million exhaustive radiological characterization survey of Area IV, the parcel of land where DOE operations took place and that is being cleaned up by DOE standards. The survey found that low levels of residual contamination from past civilian nuclear energy research affects approximately 40 acres of the 290 acres in Area IV. EPA’s measurements show that most of the radiation levels are lower than naturally occurring levels measured in nearby off-site locations. To read the EPA's study, visit EPA Radiological Characterization Study Results.

The U.S. EPA conducted an exhaustive radiological characterization survey of Area IV between 2009 and 2012. The EPA described the survey as, “one of the most robust technical investigations ever undertaken for low-level radioactive contamination.” The results of the survey will help guide remediation efforts in Area IV.

According to the EPA:

• “In general, EPA found elevated radiation levels in the areas where we expected to find them, isolated to a number of former process or disposal areas.”
• “Level of radiation throughout most of the Area IV study area was lower than the offsite background locations.”
• “This survey resulted in the discovery of several areas of elevated radiation levels, but none posed a health risk to personnel.”
• As part of the survey, the EPA took 3,735 soil samples and conducted over 128,000 separate analyses. In summary, the radiation levels found were limited and localized to certain former process and disposal areas. These results are in line with what would be expected for a facility of this type, which operated for many decades. No (0%) samples exceed the EPA acceptable risk range for open space land use.

EPA Radiological Characterization Study Results fact sheet

A 2007 study that compiled existing off-site data found no evidence of offsite radiological contamination. In an April 2013 letter to the Mayor of Simi Valley, the DTSC stated, “To date we have not found evidence of off-site contamination from SSFL that would pose a risk to human health or the environment.” in areas such as the Brandeis-Bardin Institute, Santa Susana Knolls, Moorpark and beyond. More recently, DTSC stated in the Biannual April 2018 public meeting that “DTSC has not found any evidence that contamination from [historical] operations at SSFL has posed or would pose a threat to human health or the environment outside the SSFL site boundaries.”

No. Since 1990, numerous studies conducted by government agencies, university researchers and others have examined cancer rates in the communities surrounding Santa Susana. It is not unusual for multiple studies to be conducted and come to different conclusions, which is why one must look at all of them. Taken together, the studies do not support a link between incidences of cancer and past operations at the Santa Susana Field Laboratory (SSFL).

The two most recent studies were performed by Professor Lewis Morgenstern of the University of Michigan and Professor Thomas Mack of the University of Southern California Keck School of Medicine.

A 2007 study by Professor Morgenstern concluded, “The results from this study suggest little or no association between residential distance from SSFL and the incidence of all cancers or the group of (radio-sensitive) malignancies thought to be affected by ionizing radiation. There was, however, a weak positive association during both follow-up periods between distance from SSFL and the group of (chemo-sensitive) malignancies thought to be affected by exposure to chemicals used at Rocketdyne.” The study further concluded, “Furthermore, we have no direct evidence that the associations we observed, even if they reflect real differences among the three regions, necessarily reflect the effects of environmental exposures originating at SSFL.”

A 2014 study by Professor Mack concluded, “No evidence of measurable offsite cancer causation occurring as a result of emissions from the SSFL was found. Further, no evidence of any cancer causation by any environmental factor was found.” Dr. Mack presented his findings at a DTSC public meeting in April 2014.

An overview of epidemiological and community health studies can be found here.

It is not true that 300 times permissible concentrations were released during the Sodium Reactor Experiment accident. Many people have made various statements about the 1959 Sodium Reactor Experiment incident using assumptions that are not supported by facts and data.

What we do know is the incident occurred at a time when the area around the Santa Susana Field Laboratory was still sparsely populated. Records were kept of the levels that were released and used to calculate potential exposure dose. The total radiation doses for the two month period following the SRE accident were 0.099 millirem for a hypothetical person at the Santa Susana site boundary, and 0.018 millirem for a hypothetical person at the location of the nearest resident in 1959 (1.33 miles away).

These doses are a fraction of the permissible exposure level in 1959, and today’s more restrictive federal limits, including the Nuclear Regulatory Commission and Department of Energy exposure limits for nuclear facilities (100 millirem/year) and the U.S. EPA limit for airborne emissions (10 millirem/year). Nuclear energy operations at Santa Susana ended decades ago. The SRE accident has been the subject of extensive study and commentary. Here is some additional information about the incident:

Energy Technology Engineering Center website
Department of Energy SRE Workshop
Annual Site Environmental Reports, 1955-present

No, there were no “secret releases of radiation” at the Santa Susana Field Laboratory. Radiation releases were monitored, measured and documented in compliance with federal regulations. The Santa Susana Field Laboratory continually monitored the site for potential releases and reported the results of its monitoring. The results of this sampling were documented in annual monitoring reports.

Copies of annual site environmental reports for Area IV of Santa Susana Field Laboratory from 1955 through 2014 are available on the Energy Technology Engineering Center website.

There have been two worker health studies at the Santa Susana Field Laboratory. A 1997-1999 study of Santa Susana Rocketdyne workers and simi valley cancer rates conducted by UCLA was extensively reviewed by a number of experts who questioned the study’s methodology. As a result, Boeing and the United Aerospace Workers Union (UAW) sponsored a second worker health study that was conducted by the International Epidemiology Institute and overseen by an independent Science Committee comprised of nationally renowned public health and epidemiological experts.

This study, which was completed in 2005 and updated in 2011, was peer reviewed and published in the Journal of Radiation Research. It stated, in reference to Simi Valley cancer rates, "The extended follow-up reinforces the findings in the previous study in failing to observe a detectable increase in cancer deaths associated with radiation, but strong conclusions still cannot be drawn because of small numbers and relatively low career doses.” The Science Committee likewise concluded that, “The Rocketdyne workforce had a much lower overall mortality than the rate observed in the California population. There is no evidence that working conditions caused increased mortality in the Rocketdyne workforce."

International Epidemiology Institute Worker Health Study Executive Summary
Information about UCLA Worker Health Study

No. The authors of the UCLA study did not conduct any soil, air or other environmental testing that would provide information about hazardous chemicals and radioactivity from the Santa Susana Field Laboratory that exist today, either on or offsite. The study is primarily a review of limited, historical information. In addition, the study was not subject to peer review and several experts have questioned its methodology.

Comments from Boeing and other experts on the UCLA study can be found here.
One study that did involve actual sampling was the onsite radiological characterization survey of Area IV of the Santa Susana Field Laboratory that the U.S. EPA conducted between 2009 and 2012. The EPA described the survey as, "one of the most robust technical investigations ever undertaken for low-level radioactive contamination." In summary, the radiation levels found onsite were limited and localized to certain former process and disposal areas. These results are in line with what would be expected for a facility of this type, which operated for many decades.

Final EPA Radiological Characterization Reports

Dr. Morgenstern's report states: “There is little or no association, for total cancers and radiosensitive cancers among adults.” For the few cancers for which higher rates were reported, the report concludes that "There is no direct evidence from this investigation, however, that these observed associations reflect the effects of environmental exposures originating at SSFL."

And in his April 2014 study of area cancer rates, Dr. Thomas Mack of USC Keck School of Medicine concluded: "no evidence of measurable offsite cancer causation occurring as a result of emissions from Santa Susana."

The stormwater discharge limits for the Santa Susana site in the National Pollutant Discharge Elimination System (NPDES) permit issued by the Los Angeles Regional Water Quality Control Board (Regional Board) are some of the country’s most stringent limits. Although stormwater is not used as drinking water, the numeric limits in the site’s permit, in many cases, are lower than the levels that the state of California deems safe for people to drink.

Boeing has completed the following types of projects at Santa Susana to meet the strict limits in the site’s NPDES permit:

• Designed and constructed two state-of-the-art storm water treatment systems that use processes and chemicals similar to those used by city and county municipalities to make clean drinking water;
• Installed a biofilter that was recognized by the California Stormwater Quality Association as a creative solution; and
• Removal of over 25,000 cubic yards of soil that may have been adversely affecting stormwater runoff.

Boeing works with an independent team of five internationally recognized experts who provide recommendations on how to best meet compliance objectives. Additional information on the Santa Susana Stormwater Expert Panel and their prior presentations is available here.
Over the past decade, Boeing has performed thousands of analyses on stormwater leaving the Santa Susana site to ensure compliance with the NPDES permit.  Even with the permit’s stringent limits, Boeing has maintained over 97% compliance for stormwater leaving the site. The exceedances that have occurred are generally associated with metals and inorganics at naturally-occurring levels.

No. In response to concerns expressed by community members, Boeing prepared a Human Health Risk Assessment (HHRA), an environmental risk assessment, under the direction of the Regional Board.

The HHRA evaluated potential exposure of individuals who may come into contact with stormwater from the Santa Susana Field Lab in drainage areas immediately downstream of the property boundary while hiking, rafting or other recreational uses.  The report considered possible ways recreational users could have direct exposure to the surface water, such as incidental ingestion, skin contact and inhalation.  The HHRA, which was reviewed and approved by the California Office of Environmental Health Hazard Assessment (OEHHA), concluded that:

Potential recreational exposures to Constituents of Potential Concern (COPCs) in surface water runoff exiting the Santa Susana site via Outfalls 001, 002, 008, 009, 011, 018, and 019 are below levels of concern as established by Cal-EPA and USEPA. This includes those COPCs that have had NPDES permit limit exceedances, such as lead and dioxins.

The final HHRA is located here.

No. People who live in the vicinity of the site are safe. Based on thousands of soil samples collected onsite and offsite, individuals who live near the site are not exposed to any ground contamination. The exceedances that have occurred over time in stormwater are generally caused by metals and inorganics in soil at naturally occurring levels.

Portions of our stormwater management and treatment systems were damaged in the Simi Valley fire, however, once it was safe for Boeing’s Santa Susana team to return to the site after the fire, the piping and most of the other components were fully restored to pre-fire capabilities. The majority of the repair work was completed by January 2019.

• After the Woolsey fire, Boeing collected surface water samples in response to 10 qualifying rain events and submitted the data to the Regional Board as part of the regular quarterly reports in accordance with the NPDES permit.
• While several exceedances were identified, additional laboratory analysis showed that only naturally occurring radionuclides were detected, and the Stormwater Expert Panel indicated that the other exceedances were likely the result of the wildfire and not from erosion of contaminated soil.  The Expert Panel is still evaluating the data and will include findings on the cause of the exceedances in their 2019 Annual Report, which will be available here.   

The California Water Code states that penalties do not apply when permit violations are caused by unanticipated, grave natural disasters like the Woolsey Fire. The Regional Board has determined that the exceedances detected at Santa Susana were due to the Woolsey Fire. The only penalties assessed against Boeing were for dioxin because they are excluded from the natural disaster exemption.

The Stormwater Expert Panel wrote a memorandum explaining why surface water doesn’t continually flow from the site into the Bell Canyon neighborhood. Flow in Bell Canyon in the dry season is from groundwater emerging in springs and through runoff from neighborhood activity. The spring water has been tested and there are no site-related ground contaminants present in the Bell Canyon drainage downstream of the Santa Susana Field Lab property boundary. There also has been extensive soil testing in drainages in Bell Canyon and there are no site-related ground contaminants in the drainages south of the Santa Susana property boundary.