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Department of Toxic Substances Control 

Maziar Movassaghi Linda S. Adams Arnold Schwarzenegger Acting Director Secretary for Governor 

700 Heinz Avenue Environmental Protection 

Berkeley, California 94710-2721 

May 13, 2010 

Michael M. Montgomery 


Assistant Director; Superfund Division 


U. S. EPA (SFD-8) 


75 Hawthorne Street 


San Francisco, California 94105 


Dear Mr. Montgomery: 

This letter is in regard to the GBF Dump Site (Site) in Antioch, California. DTSC 

requests that the U.S. EPA de-propose the site from the National Priorities List (NPL) 

and remove it from consideration as an NPL site. The site was proposed for the NPL in 

1988 and subsequently de-proposed in 1989 after it was re-scored and the score 

dropped below the scoring threshhold. The US EPA prepared another Hazard Ranking 

Package and re-proposed the site to the NPL in 1992. 

Before the second proposed listing, DTSC sent a letter to EPA requesting that the GBF 

site not be listed on the NPL. EPA's policy at that time was to list sites regardless of 

other agency involvement with the cleanup, so EPA proceeded with the proposed 

listing. This policy changed soon after and now EPA can defer listing if it is being 

cleaned up under State authority. 

DTSC has worked on the site cleanup for many years with the responsible party, GBF 

Holdings, LLC. In 1988 the California Department of Health Services, a predecessor to 

DTSC, issued Remedial Action Order No. HSA 87/88-012 to the current and historic site 

operators, owners, and hazardous waste generators in order to initiate site 

characterization and remediation efforts. In 1997, following several years of soil, 

groundwater, and landfill gas investigations, DTSC developed a Remedial Action Plan 

(RAP) for the site identifying groundwater pump-and-treat remedy at the landfill source 

area and the plume leading edge. The current owners of the site (and the liability), GBF 

Holdings LLC, entered into a consent order (HSC-CO 01/02-007) with DTSC and have 

been operating under this consent order for the past nine years. At that time, DTSC 

and GBF decided to divide the remedial efforts into two phases: landfill source 

remediation (Phase I) and down-gradient groundwater plume remediation (Phase II). 
Michael M. Montgomery 

May 13, 2010 

Page 2 

In 2001 and 2002, a landfill cap was installed and the landfill was certified closed by the 

Sacramento Regional Water Quality Control Board in 2002. The landfill is maintained 

and a landfill gas collection and treatment system is currently operating. In 2002 and 

2003, the Phase I groundwater extraction and treatment system (GWETS) was installed 

along the northern boundary of the landfill (downgradient edge of landfill). The GWETS 

consists of 30 extraction wells and a treatment system (activated carbon). Treated 

groundwater is currently discharged, under permit, to the Delta Diablo Sanitation District 

(DDSD). 

DTSC is currently in the process of preparing the Five Year Review for the Phase I 

GWETS and working with GBF Holdings, LLC to identify measures to increase the 

efficiency of the system. DTSC is also currently in the process of working with GBF 

Holdings, LLC to re-evaluate potential remedial alternatives to address the distal portion 

of the groundwater plume. As part of the re-evaluation, DTSC has required soil vapor 

sampling to be conducted in areas of historic high chlorinated solvent concentrations in 

groundwater. Semi-annual groundwater monitoring and site inspections are currently 

ongoing. 

DTSC believes that Superfund involvement at this site is not warranted, as the cleanup 

has progressed successfully and GBF Holdings is working cooperatively with the State. 

DTSC requests that EPA de-propose the GBF Dump from the NPL and allow the State 

to continue with the site cleanup. 

If you have any questions, please contact Jonathan Largent of my staff at (510) 540­

3826 or JLargent@dtsc.ca.gov. 


Sincerely, 

b~l'<v~/~ {J~ Barbara J. coU.E. 

Acting Assistant Deputy Director 

California Department of Toxic Substances Control