Pictured: Santa Susana Field Lab. 

by Kimberly Rivers

A peer-reviewed study (1) published in the December 2021 issue of Journal of Environmental Radioactivity (JER) has found that radioactive contaminated particles were spread during the 2018 Woolsey Fire from Santa Susana Field Lab (SSFL) to offsite locations. 

This finding is contrary to state reports released in 2020.

SSFL, located between Simi Valley and Agoura Hills, is the former site of extensive rocket fuel testing and where a partial nuclear meltdown occurred in 1959. The event and the resulting radioactive contamination was covered up for decades. Local residents continue to fight for a full clean up of the site today. 

LOCAL CLEAN UP EFFORT HIGHLIGHTED IN DOCUMENTARY | In the Dark of the Valley (acquired by MSNBC) follows the story of Simi Valley resident Melissa Bumstead and other local mothers whose children have been diagnosed with rare cancers and are fighting for the Santa Susana Field Lab to be fully cleaned up. The film has won numerous awards on the festival circuit, including Best Documentary at the Phoenix and Catalina film festivals. The film aired nationwide on Nov. 14 and will air again on MSNBC Sunday, Nov. 21, 5 p.m., and is streaming on MSNBC. Pictured: Still from In the Dark of the Valley, showing the incidents of rare childhood cancers documented in the communities surrounding Santa Susana Field Lab. 

The JER study found radioactive particles associated with the fire at SSFL as high as 19 times background (normal) as much as nine miles away from SSFL, demonstrating contamination did leave the laboratory site. The study did note that widespread contamination from SSFL did not occur outside the perimeter of the lab property, where there were certain clustered areas of confirmed contamination from the lab. Those areas were in Simi Valley and Thousand Oaks. 

The study summary noted that one sample labeled as 180 A, “collected 15 km from the SSFL perimeter (in Thousand Oaks, CA) had the highest alpha count rate of the entire sample set.” 

Seventy mph winds were reported when the Woolsey Fire was burning in November of 2018 and concerns were quickly raised about the spread of radioactive contamination from the SSFL. The state monitored and took samples, and issued a report in 2020, but this new study, based on a much larger sample set, made different findings. 

The newly released study is based on 360 samples of “house dust, surficial soils and ash,” with collection beginning in December 2018 and concluding February 2019. Samples came from private residences, with permission, public areas, and public areas along the SSFL fence line. According to the study summary, “community-volunteer citizen-scientists” were trained in “sample collection and safety protocols before collecting samples.” The areas sampled were from a 16 km radius around the perimeter of the SSFL property, including rural, urban, suburban and mountainous open space areas. 

Map showing locations of contamination found in the JER report and proximity to the Santa Susana Field Lab.

The report found that while 97% of the samples collected matched the expected “normal” background levels of various compounds, samples taken from “offsite” SSFL close to the property perimeter “had the highest alpha-emitting radionuclides radium, thorium, and uranium activities, indicating site-related radioactive material has escaped the confines of the laboratory.” 

The study did not find and does not claim “widespread deposition of radioactive particles. However, two radioactive deposition hotspots and significant offsite contamination were detected near the site perimeter.”

The JER study also cites climate change as a factor in changing the impacts of fires that occur over soil containing contamination. 

“The potential impact of climate change on radionuclide transport is two-fold, as increasing drought, fire frequency, and increased precipitation intensity result in greater post-fire stormwater transport of contaminated sediments. This increase is over and above the typical increase in runoff and sediment yield after wildfires.”

Sampling of ash by trained citizen scientists. Dec. 2, 2018. Photo submitted. 

 This new study’s finding are contrary to what the California Environmental Protection Agency (CalEPA) reported in 2020 (2), which was that no contamination left the laboratory area as a result of the Woolsey Fire. 

The Woolsey Fire began at the SSFL site on Nov. 8, 2018 and concerns were quickly raised about the high winds and smoke carrying contamination offsite. The California Department of Toxic Substances Control (DTSC) set up air monitoring equipment on Nov. 10, 2018 to determine whether contamination spread and released a report of the results in December 2020. The state took samples of air, ash and soil from 22 locations. The findings of that state research “did not identify a release of contaminants from SSFL. Like the interim report, this final report also finds the risk from exposure to smoke during the Woolsey Fire was not higher than what is normally associated with wildfire.”

DTSC is one of the state agencies responsible for overseeing the clean up of the site. Local residents and scientists say the cleanup has been delayed, and the community is being harmed due to the state’s failure to ensure proper and full cleanup of the contamination. 

  1. Radioactive microparticles related to the Woolsey Fire in Simi Valley, CAhttps://www.sciencedirect.com/science/article/pii/S0265931X21002277?dgcid=author
  2. https://dtsc.ca.gov/wp content/uploads/sites/31/SSFL/DTSC_Final_Summary_Report_of_Woolsey_Fire.pdf