Department of Toxic Substances Control 

Matthew RodrIquez 

Secretary for 

Environmental Protection 

February 1, 2013 

Michael Montgomery 

Deborah O. Raphael, Director 

5796 Corporate Avenue 

Cypress, California 90630 

U.S. Environmental Protection Agency, Region IX 

75 Hawthorne Street, Mail Code SFD-6-2 

San Francisco, California 94105 

Edmund G. Brown Jr. 

Governor 

DTSC RESPONSE TO THE U.S. ENVIRONMENTAL PROTECTION AGENCY 

REQUEST FOR STATE CONCURRENCE FOR THE NATIONAL PRIORITY LIST 

PARTIAL DELISTING OF MARINE CORPS AIR STATION EL TORO, IRVINE, 

ORANGE COUNTY 

Dear Mr. Montgomery: 

The Department of Toxic Substances Control (DTSC) received an undated letter on 

November 15, 2012 from your office, requesting state concurrence to partially delist 

portions of the form~r Marine Corps Air Station EI Toro (EI Toro Base) from the National 

Priorities List (NPL). As outlined in your letter, U.S. Environmental Protection Agency, 

Region IX, (U.S. EPA, Region 9), proposes to initiate the streamlined direct final 

deletion process set forth in 40 CFR 300.425(e) and 60 FR 55465 to partially de-list 

1,958.6 acres at the former EI Toro Base. 

U.S. EPA, Region 9 has determined that the NCP criteria have been satisfied for a 

significant and contiguous portion of the EI Toro Base. Pursuant to the National 

Contingency Plan (NCP), U.S. EPA may delete sites from the NPL when it determines 

with state concurrence that (1) responsible parties have implemented "all appropriate 

response actions required," or (2) remedial investigations have shown that "the release 

of hazardous substances pose no significant threat to public health or the environment, 

and therefore, takingof remedial measures is not appropriate." (40 CFR § 300.425(e). 

Additionally, U.S. EPA may partially delete areas from the NPL where a portion of the 

site meets thestandards'set forth in 40 CFR 300.425(e). (60 FR 55465, November 1, 

1995). 

As you know, since 2004, the Department of the Navy has issued seven Finding of 

Suitability to Transfer (FOST) documents for EI Toro Base. In each case, U.S. EPA and 

DTSC concurred with remedial findings and the suitability of transfer determination. 
Mr. Michael Montgomery 

February 1, 2013 

Page 2 

Information enclosed with your letter included Attachment A, which showed the areas 

proposed for partial deletion, Attachment B -1 which provided a Summary of 

Investigation and Remedial Actions implemented at EI Toro Base organized by FOST, 

and Attachment B-2 which provided a map that identifies the areas investigated and 

remediated as set forth in the FOST documents and areas that still require further work. 

DTSC has reviewed. the information provided and concurs with the request to delist 

1,958.6 acres within the former EI Toro Base from the NPL. DTSC agrees that all 

appropriate and required actions under the Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA) have been implemented and no further 

investigation or cleanup is required for the 1,958.6 acres within the former EI Toro Base. 

However, within the proposed area are several carve-out parcels to remain on the NPL 

(III-B, II-C, II-D, II-H, and I-F). DTSC agrees those parcels should remain on the NPL. 

In particular for Carve-out I-F, ongoing supplemental investigations to delineate the 

groundwater plume at Installation Restoration Program (IRP) Site 16 is occurring and 

the downgradient extent of contaminated groundwater at IRP Site 16 is unknown. 

DTSC understands that the Department of the Navy will recommend new monitoring 

well locations and screening intervals to optimize the groundwater monitoring network at 

IRP Site 16. This optimization should provide information on the downgradient extent of 

the groundwater contamination at IRP Site 16. DTSC will reevaluate IRP Site 16 and 

the associated area, Carve-out I-F, depending on what the pending sampling and 

monitoring reveals on the extent of contaminated groundwater at IRP 16. 

DTSC understands that portions of the EI Toro Base proposed for delisting from the 

NPL may require five~year reviews to assess protectiveness. A site can be deleted from 

the NPL even thoughfive~year reviews are required. 

If you have any questions regarding this letter, please contact Eileen Mananian, Project 

Manager, at (714) 484~5349 or by email atEileen.Mananian@dtsc.ca.gov. 

Sincerely, 

Thomas M. Cota 

Branch Chief 

Brownfields and Environmental Restoration Program 

cc: See next page. 
Mr. Michael Montgomery 

February 1, 2013 

Page 3 

cc: James Callian PG, CEG, CHG 

BRAC Environmental Coordinator 

Marine Corps Air Station EI Toro 

Base Realignment and Closure 

7040 Trabuco Road 

Irvine, California 92618 

james.caliian@naVY.mil 

Content Arnold 

BRAC PMO West 

1455 Frazee Road, Suite 900 

San Diego, California 92108 

content.arnold@naVY.mil 

Mary Aycock 

U.S. Environmental Protection Agency, Region IX 

75 Hawthorne Street, Mail Code SFD-6-2 

San Francisco, California 94105 

Aycock.Marv@epamail.epa.gov 

John Broderick 

Regional Water Quality Control Board, Santa Ana Region 

3737 Main Street, Suite 500 

Riverside, California 92501-3339 

John.Broderick@waterboards.ca.gov 

Robert Woodings 

Restoration Advisory Board Co-chair 

11 Teal 

Irvine, California 92604 

Marcia Rudolph 

Restoration Advisory Board Subcommittee Chair 

24922 Muirlands, Suite 139 

Lake Forest, California 92630 

Thelma Estrada 

Environmental Protection Agency, Region 9 

Office of Regional Counsel 

Estrada.Thelma@epa.gov 

Loren Henning 

Air Force & DOE Section Chief 

Henning.Loren@epa.gov 
Mr. Michael Montgomery 

February 1, 2013 

Page 4 

Stewart w. Black, P.G. 

Deputy Director 

Brownfields and Environmental Restoration Program 

Dan T. Ward, P.E, 

Statewide DOD Cleanup Manager 

Cleanup Program 

Barbara J. Cook, P.E. 

Assistant Deputy Director 

Brownfields and Environmental Restoration Program