Laserfiche WebLink
i <br /> Harding Lawson Associates <br /> 91 PIS iR - pH - <br /> March 1, 1999 <br /> 38737 004 �• <br /> Mr. Michael J. Infurna,Jr., REHS - <br /> a � <br /> San Joaquin County Public Health Services - <br /> Environmental Health Division <br /> 304 East Weber Avenue,Third Floor <br /> Stockton, California 9520.2, <br /> Revised Work Plan Addendum Number 3-and <br /> Scheduling of.Field Work <br /> Supplemental Site Investigation <br /> Tri Valley Growers Plant T <br /> 26200 North Galt Road <br /> Thornton, California <br /> Site Code: 1920 <br /> Dear Mr. Infurna: <br /> On behalf of Tri Valley Growers(TVG),Harding Lawson Associates (HLA) submits to San Joaquin County <br /> Public Health Services,,Environmental Health Division(PHS/EHD),Revised Work Plan Addendum <br /> Number 3 for the supplemental site investigation being performed at the above.referenced Underground <br /> Storage Tank (UST) site. On February 17?, 1999, a meeting was held at PHS/EHD offices attended by <br /> yourself and Ms. Margaret Lagorio of the PHS/EHD,.Mr. Mark List of the.Regional Water Quality Control <br /> Board (RWQCB), Mr. Chris Savage of Tri Valley Growers(TVG),and Mssrs. Michael J. Leacox and Gary.D. <br /> Haeck of Harding Lawson Associates (HLA). The purpose of meeting.was to discuss recent fieldwork <br /> findings that suggest a deeper plume of impacted groundwater may be present at the Site and the <br /> implications of these findings on completing site characterization and submission of a no-further-action <br /> request. The purpose of this Revised Work Plan Addendum Number 3 is to present a scope of work l <br /> proposed by TVG to confirm or refute the Hydropunch analytical data (or the suggested presence of a <br /> deeper groundwater phnue). <br /> BACKGROUND <br /> As described in HLA's Work Plan Addendum.;dated January 14, 1998, and Work Plan Addendum Number <br /> 2, dated March 19, 1998, She objective of the Supplemental Site Investigation was to collect the additional <br /> data required to submit a site closure-request as a "low risk"groundwater site. As discussed during the <br /> recent meeting, the field work performed-on March 26 and 27, 1998, included drilling three soil borings <br /> (HP-1, HP-2, and HP-3) to depths of 21.0, 56.0, and 25.5 feet below the ground surface (bgs) at the former <br /> UST location. Soil and groundwater samples were collected from the borings and analyzed for petroleum <br /> hydrocarbons. Some of the objectives of the work have been achieved. The vertical and lateral extent of <br /> impacted soil has been determined. However, analytical results from the groundwater samples indicate <br /> that dissolved petroleum hydrocarbons are present in the groundwater at depths below where previously <br /> identified. ; <br /> Analytical results on Hydropunch groundwater samples collected at depths of 22 to 28 feet bgs detected <br /> total petroleum hydrocarbons as gasoline(TPHg) and benzene concentrations ranging from 0.6 to 2.3 <br /> Engineering and <br /> Environmental Services 10265 Rockingham Drive,Suite 150,Sacramento,CA 95827 916/364-0793 Fax:916/364-5633 <br />