## Department ofToxic Substances Control

MatthewRodrIquez 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 EdmundG. 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 CORPSAIR STATION ELTORO, IRVINE, ORANGE COUNTY

Dear Mr. Montgomery:

The Department ofToxic Substances Control (DTSC) received an undated letteron November 15, 2012 from your office, requesting state concurrence to partially delist portions ofthe**form~r** Marine CorpsAirStation 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 directfinal deletion process setforth in 40 CFR 300.425(e) and 60 FR 55465to partially de-list 1,958.6 acres atthe former EI Toro Base.

U.S. EPA, Region 9 has determined thatthe NCP criteria have been satisfied for a significant and contiguous portion ofthe EI Toro Base. Pursuantto the National Contingency Plan (NCP), U.S. EPA may delete sitesfrom the NPLwhen it determines with state concurrencethat (1) responsible parties have implemented "all appropriate response actions required," or (2) remedial investigations have shown that "the release of hazardous substances pose no significantthreatto public health orthe environment, and therefore, takingof remedial measures is not appropriate." (40 CFR 

### § 300.425(e). Additionally, U.S. EPA may partially delete areas from the NPLwhere aportion ofthe site meetsthestandards'setforth in 40 CFR 300.425(e). (60 FR 55465, November 1, 1995).

As you know, since 2004, the Departmentofthe Navy has issued seven Finding of SuitabilitytoTransfer (FOST) documentsfor EI Toro Base. In each case, U.S. EPA and DTSC concurred with remedial findings and the suitability oftransfer determination.Mr. Michael Montgomery February 1, 2013 Page 2

Information enclosed with your letter included AttachmentA, 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 mapthat identifiesthe areas investigated and remediated as setforth in the FOST documents and areas that still require furtherwork.

DTSC has reviewed.the information provided and concurs with the requestto delist 1,958.6 acres within theformer EI Toro Base from the NPL. DTSC agreesthat all appropriate and required actions underthe Comprehensive Environmental Response, Compensation, and LiabilityAct (CERCLA) have been implemented and no further investigation or cleanup is required forthe 1,958.6 acres within the former EI Toro Base.

However, within the proposed area are several carve-out parcelsto 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 particularfor Carve-out I-F, ongoing supplemental investigationsto delineate the groundwaterplume at Installation Restoration Program (IRP) Site 16 is occurring and the downgradient extent ofcontaminated groundwater at IRP Site 16 is unknown. DTSC understands thatthe Department ofthe Navywill 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 groundwatercontamination at IRP Site 16. DTSC will reevaluate IRP Site 16 and the associated area, Carve-out I-F, depending on whatthe pending sampling and monitoring reveals on the extent ofcontaminated groundwaterat IRP 16.

DTSC understands thatportions ofthe EI Toro Base proposed for delisting from the NPL may require**five~year** reviews to assess protectiveness. A site can be deleted from the NPLeven**thoughfive~year** reviews are required.

Ifyou have anyquestionsregarding 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

ContentArnold 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

RobertWoodings 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.govMr. 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