Site Mitigation & Restoration Program

We protect and maintain California’s land and places
by setting strict standards for land restoration and cleanup

Santa Susana Field Laboratory NASA Groundwater CMS & SB Phase 1

Santa Susana Field Laboratory

The California Department of Toxic Substances Control (DTSC) invites public comments on the NASA Phase 1 Groundwater Corrective Measures Study (GW CMS) and Statement of Basis (SB) for groundwater cleanup at the Santa Susana Field Laboratory (SSFL) in Ventura County, California. Under the Resource Conservation and Recovery Act (RCRA), the SB explains the rationale behind the proposed corrective actions based on the findings in the CMS. Public input throughout the corrective action process, including commenting on the CMS and the SB, is crucial for DTSC to select the most appropriate cleanup remedy. The public comment period will run from April 29, 2025, to June 10, 2025, including a public meeting to discuss these preliminary documents.

Purpose of GW CMS and SB

The NASA Phase 1 GW CMS evaluates potential cleanup methods to address NASA areas of SSFL with the highest groundwater and bedrock concentrations of trichloroethylene (TCE). It aims to identify effective cleanup methods to protect human health and the environment. The SB outlines DTSC’s proposed remedy, and the key information used in the decision-making process.

The corrective action process is divided into two phases:

Phase 1 (this public comment period): Focuses on areas with high concentrations of TCE in groundwater and soil vapor, and seep areas.
Phase 2 (planned for 2027): Evaluates and identifies remedies for all remaining NASA groundwater and soil vapor contamination.

Key Documents

The following documents will be available for public review during the public comment period:

NASA Draft Phase 1 Groundwater Corrective Measures Study (submitted January 2024)
DTSC Draft NASA Groundwater Phase 1 Statement of Basis (submitted April 2025)

Public Participation

DTSC encourages the public to review the documents, attend the public meeting, and provide comments. Comments can be submitted from April 29, 2025 through June 10, 2025, through the following channels:

Verbally at the public meeting on May 13
Online: Submit Public Comment Tool
Email: DTSC_SSFLPublicComments@dtsc.ca.gov
Mail (Postmarked by June 10): DTSC, Attn: Paul Carpenter, SSFL NASA GW CMS SB Phase 1 Public Comment, 8800 Cal Cal Center Drive, Sacramento, CA 95826

Public Meeting

The public meeting scheduled for Tuesday, May 13, 2025, from 6:00-8:00pm, will cover the NASA Phase 1 GW CMS and the SB.
Register here: https://bit.ly/NASAGWCMSSBPH1

Important Dates

April 29. Release of documents for public comment.
April 29 to June 10. Public Comment Period.
May 13. Public meeting.
June 10. Deadline to submit public comments.
June 10 to Fall 2025. DTSC will evaluate comments received during the public comment period and summarize them in a Response to Comments (RTC) document.
Fall 2025. DTSC releases the final NASA Phase 1 GW remedy decision and RTC document.