California regulators have approved the first phase of NASA’s groundwater cleanup plan for the Santa Susana Field Laboratory, marking an important step at the former rocket-engine testing complex overlooking the western San Fernando Valley.
The California Department of Toxic Substances Control approved NASA’s Phase 1 Groundwater Corrective Measures Study on January 16, 2026. NASA highlighted the decision in its Summer 2026 FieldNOTE newsletter.
The approval does not mean the cleanup is complete. NASA must still prepare a detailed implementation plan and receive additional state approval before full-scale treatment begins.
Treating the Most Contaminated Areas
The first phase targets four areas within NASA’s approximately 450-acre portion of the former Rocketdyne property where trichloroethylene, or TCE, and related chemicals have been detected at their highest concentrations.
TCE was widely used to clean rocket engines and other equipment during the site’s decades of aerospace testing. The chemical later entered groundwater and fractured bedrock beneath the property.
The approved cleanup combines several methods, including pumping and treating contaminated groundwater, extracting chemical vapors from bedrock and stimulating microorganisms that can break down contaminants underground.
NASA estimates that approximately 10 years of active treatment could reduce the highest concentrations in the Phase 1 areas by about 90 percent. However, DTSC says groundwater treatment and monitoring are expected to continue for several decades.
NASA reports that its existing interim systems and pilot programs have already treated nearly 540 million gallons of groundwater and removed approximately 6,000 pounds of TCE and other volatile organic compounds.
Only the First Phase
Phase 1 does not address all groundwater contamination beneath NASA’s property. Remaining areas and additional chemicals are expected to be evaluated through a separate Phase 2 study, which NASA currently expects to submit to DTSC in early 2028.
The limited scope has drawn concerns from local governments and environmental groups about how the remaining contamination will be addressed and whether the groundwater can ultimately be restored to required standards.
NASA expects to complete its Phase 1 implementation plan in early 2027. Treatment would begin after DTSC reviews and approves that plan.
Rocket-Test Structures Continue to Disappear
The newsletter also reports that NASA completed another demolition phase in the former Coca Test Area.
Coca Test Stand 4, which once stood more than 200 feet tall, was dismantled in December 2025. NASA plans a future phase to remove remaining foundations, concrete pads, asphalt and the Coca Control House, depending on federal funding.
The Coca test stands supported engines associated with the Apollo and Space Shuttle programs. Selected artifacts were transferred to the California Science Center and Smithsonian National Air and Space Museum for possible future display.
A Milestone, Not the Finish Line
Approval of the Phase 1 remedy is a meaningful milestone after decades of investigations, pilot programs and disputes over the cleanup. It establishes a path toward treating some of the most heavily contaminated groundwater beneath NASA’s property.
Physical implementation remains ahead, Phase 2 is still being developed and the separate soil cleanup continues to face major logistical and regulatory questions.
For nearby communities including Chatsworth, West Hills, Bell Canyon and Simi Valley, the next measure of progress will be when full-scale treatment begins—and how contamination outside the first-phase areas will ultimately be addressed.
The SFV Blog has documented Rocketdyne and the Santa Susana Field Laboratory for more than 15 years, covering the site’s aerospace history, nuclear accident, contamination, cleanup disputes, demolition and eventual reuse.
More than a decade after the blog’s tours of the property, many of its historic test structures have disappeared. The much more difficult work of treating what remains underground is only now approaching its next major phase.
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