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ADDITIONAL GROUNDWATER INVESTIGATION,
<br /> MONITORING WELL DESTRUCTION AND INSTALLATION,AND
<br /> INTERIM REMEDIATION PUMP TEST REPORT
<br /> Boyett Petroleum
<br /> 419 S. Main Street, Manteca, CA
<br /> 1.0 INTRODUCTION
<br /> Groundwater' investigation activities were conducted on October 20 through 23, 2003, at the Bdyett Petroleum facility (site) located at 419 S. Main Street in Manteca, California (Figures L and 2, Appendix
<br /> A). Monitoring well destruction, installation, survey, and development activities were conducted between
<br /> October 29 and November 14, 2003. A 72-hour continuous pump test was conducted from November 18
<br /> through 21, 2003. The work was directed by Mr. Nuel Henderson, Jr. and Mr. Jeffrey Wong of the San
<br /> Joaquin County Environmental Health Department (SJCEHD) in a letter dated May 29, 2003, and
<br /> performed in general accordance with the Additional Groundwater Investigation Work Plan, dated June
<br /> ' 25, 2003, and Interim Remediation Work Plan, dated June 25, 2003. This report was prepared by Condor
<br /> Earth Technologies, Inc. (Condor) at the request of Mr. Dale Boyett of Boyett Petroleum(owner).
<br /> The purpose of the additional groundwater investigation was to evaluate the lateral and vertical extent of
<br /> ' the methyl tertiary-butyl ether (MTBE) contaminant plume in groundwater up-gradient and down-
<br /> gradient of the underground storage tanks (USTs) at the site using direct push boring methods [cone
<br /> penetrometer testing (CPT) and hydropunch]. The work included advancement of four deep CPT/direct
<br /> ' push boring pairs and Eve shallow direct push borings (Figure 3, Appendix A). Well destruction and
<br /> installation activities included the destruction of monitoring wells (MW-1, MW-4, and MW-5) and the
<br /> installation, survey, and development of four on-site, monitoring wells (MW-4R, MW-10, MW-11, and
<br />' EW-l). Monitoring well graphics are included on the geologic logs in Appendix B. The purpose of the
<br /> aquifer pump test was to characterize the aquifer and to determine aquifer response to groundwater
<br /> extraction as a possible remediation method. The results of the pump test will be used to size system
<br />' components for containment of the contaminant plume, and treatment and discharge of the groundwater.
<br /> Charts reflecting pump test activities are provided in Appendix C.
<br />' All work conducted by Condor was performed under the supervision of a California Registered Geologist.
<br /> The fieldwork and reporting were conducted in accordance with SJCEHD and California Regional Water
<br /> Quality Control Board(CRWQCB) guidelines and requirements. This report includes project background
<br /> information, a description of the fieldwork and laboratory procedures and analytical results, a discussion
<br />' of the results of the investigation, and recommendations.
<br /> 2.0 PROJECT BACKGROUND
<br />' On November 20 and 21, 1996, soil sampling was conducted at the site by WHF,-Inc., (WHF) under the
<br /> direction of Mr. Robert McClellon of the SJCEHD, One soil sample was collected from beneath each of
<br /> the site's three existing fiiel dispensers at a depth of approximately two feet below the dispenser piping
<br />' and four discrete soil samples were collected to characterize approximately 44 cubic yards of soil
<br /> stockpiled at the site. The stockpiled soil was from demolition and retrofit activities at the site. The soil
<br /> samples were analyzed for total petroleum hydrocarbons quantified as gasoline (TPH-G), for benzene,
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<br />, . Cihyl E)C[ILCIIC, ioiuene, iotai xylenes (B T EX), and for M'1'.BE.
<br /> On October 5, 1998, WHF completed two soil borings to a maximum depth of 18 feet below ground
<br />' surface (bgs) next to the fuel dispenser island. Three soil samples were collected from each boring at
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<br />' �� CONDOR
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