- California regulators proposed a penalty of nearly $600,000.
- The case involves thirty-nine stormwater discharge violations.
- Contaminants included dioxin, heavy metals, sulfate and pH issues.
- A public hearing is tentatively scheduled for February 2026.
Wednesday, December 3, 2025 — The Los Angeles Regional Water Quality Control Board
announced yesterday a proposed penalty of nearly $600,000 against The Boeing Company for alleged stormwater discharge violations at the former Santa Susana Field Laboratory in Ventura County. The board reported thirty-nine violations between January 2023 and March 2025 involving discharges of 2,3,7,8-tetrachlorodibenzo-p-dioxin, lead, mercury, manganese, iron, sulfate, and pH.
The proposed action is structured as an administrative civil liability. Staff members outlined the violations after reviewing monitoring data from storm events that carried runoff from the site into nearby creeks. These waterways are not drinking water sources, but they remain vulnerable to contamination from historic industrial activities.
Russ Colby, the board’s assistant executive officer, stated that “the proposed penalty holds the company accountable for its actions and is a necessary step to protect the waterways that continue to receive runoff from the site.”
A Legacy of Contamination at a Historic Research Site.
The Santa Susana Field Laboratory is a 2,850-acre facility located about thirty miles from downtown Los Angeles. From 1947 through 2006, Boeing and its predecessors, along with the National Aeronautics and Space Administration and the Department of Energy, conducted research and testing that included rocket engines, small-scale nuclear reactors, and chemical laser development. After the facility shut down in 2006, agencies documented extensive contamination in both soil and groundwater.
Runoff remains a significant concern because stormwater can mobilize pollutants that have persisted in the landscape for decades. Monitoring data help regulators determine whether cleanup and maintenance activities are reducing the amount of contamination entering local waterways.
Relationship to California’s 2022 Cleanup Framework.
In 2022, the California Environmental Protection Agency announced a comprehensive cleanup framework designed to guide remediation at the Santa Susana site. That framework divides responsibilities between two CalEPA agencies. The Department of Toxic Substances Control oversees soil cleanup, while the Los Angeles Water Board monitors water quality.
The proposed penalty released on December 2 is not part of the 2022 framework. Instead, it is a separate enforcement action based on recent monitoring results.
Next Steps and Public Hearing.
The Los Angeles Water Board tentatively plans to hold a public hearing on February 26, 2026. The board will accept written comments before deciding whether to finalize the proposed penalty. If approved, the penalty would reinforce ongoing oversight of stormwater compliance at the site while cleanup work continues under state directives.
With nearly ten million residents, the Los Angeles region contains a wide mix of land uses, ranging from agricultural areas in Ventura County to dense residential and industrial districts in Los Angeles County. This diversity underscores the importance of managing runoff and water quality throughout the region, particularly in watersheds affected by legacy contamination.
Image: Aerial photograph of Area IV (4) of the Santa Susana Field Laboratory
, in the Simi Hills, Ventura County, Southern California. U.S. Department of Energy, August 2007.
