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S ti
<br /> - San Joaquin County
<br /> i Q u.l my c EnvironDIRECTOR
<br /> mental H
<br /> PHealth Department Donna Heran,RENS
<br /> �o oL 600 East Main Street, PROGRAM COORDINATORS
<br /> Stockton, California 95202-3029 Margaret ragor;o,REHS
<br /> NkT
<br /> 4t _ ` ` _ • Robert McCallon-,REHS
<br /> -� Jeff Carruesco,REHS,RDI
<br /> c --y - �P Website: www.sjgov.org/ehd Kasey Foley,REHS
<br /> i 4�rF0Ra `: 'Phone::(209) 468-3420
<br /> Fax: (209)464-0138
<br /> October 8, 2009
<br /> 1
<br /> Ms. Jennifer Sedlachek Mr. Kevin Meeks
<br /> ExxonMobil Environmental Services Company Mr. Pat and Ms. Kathleen Meeks
<br /> 4096 Piedmont Avenue #194` 25355 Highway 99
<br /> Oakland, California 94611 Acampo, California 95220
<br /> Subject: Meeks RV (former Pacific Auto Center)
<br /> 25355 North Highway 99 .
<br /> Acampo, California 95220
<br /> The San Joaquin County Environmental Health Department (EHD) has reviewed Work
<br /> i Plan for Soil Vapor Assessment (soil vapor work plan), dated June 25, 2009, and Work
<br /> ' Plan for Well Installation (well installation work plan), dated September 11, 2009, prepared
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<br /> by Environmental Resolutions, Inc. (ERI) for the above•referenced site on your behalf.
<br /> The work plans were submitted in response 'to EHD's letter dated March 27, 2009,
<br /> recommending you address the threat posed by soil vapor.intrusion inside buildings
<br /> ` located onsite, and install additional monitoring• wells to define the 1,2-dichloroethane
<br /> _ (1,2-DCA) plume.
<br /> In the soil vapor work plan; ERI .proposes to advance six dual-completion soil vapor
<br /> sampling (SVS) wells at locations illustrated on Plate 2 of the work plan. The dual-
<br /> completion wells will be screened usinga three-inch probe diffuser at approximately four-
<br /> and-three-quarters feet and fourteen-and-three-quarters feet below surface grade (bsg).
<br /> The EHD approves the SVS wells advanced to approximately five feet bsg, but does not
<br /> approve the SVS wells advanced to total depth of approximately fifteen feet bsg. If
<br /> I technical justification can be provided to support collecting- soil gas samples at
<br /> t approximately fifteen feet bsg, the EHD may reconsider this decision. Of the six proposed
<br /> five-foot SVS wells, the EHD approves the locations for SV1, SV2, and'SV3. The EHD
<br /> recommends that you relocate SV4 between B4 and P2. The EHD does not approve
<br /> installation of SV5 and SV6 since these two proposed borings are distant from the source
<br /> area.
<br /> ERI proposes to analyze select soil samples for total petroleum hydrocarbons (TPH)
<br /> quantified as diesel (TPH-d);TPH quantified as.gasoline (TPH-g); benzene, toluene, ethyl
<br /> benzene, and total xylenes (BTEX); methyl tertiary-butyl ether (MTBE), ethyl tertiary-butyl,
<br /> 1 ether (ETBE), tertiary-amyl methyl ether (TAME), di-isopropyl ether (DIPE), tertiary butyl
<br /> j alcohol (TBA), 1,2-DCA, 1,2-dibr6moethane (EDB); and physical properties: moisture f
<br /> I content, dry bulk density, grain density, total porosity, air-filled porosity, water-filled
<br /> porosity, effective and specific permeability to air, effective porosity, specific permeability
<br /> to water, hydraulic conductivity, intrinsic permeability,. particle size distribution, and total
<br /> organic carbon and fraction organic carbon.
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