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' First Quarter Monitoring and Sampling Report, 1993 May 19, 1993
<br /> Southland Site No 20680, 9110 Thornton Road, Stockton, CA 4
<br /> pumping wells PW-1, PW-2, and PW-3, and former recovery well RW-1 reported benzene and TPH-G
<br /> concentrations below method detection limits (MDLs) in all samples Analytical results of the
<br /> groundwater sample collected from monitoring well MW-1 on April 2, 1993, reported a total xylene
<br />' concentration of 0 7 parts per billion
<br />' Water samples were collected from domestic wells 8968, 9036, 1912, 9144, 9156, and 9172 on
<br /> January 22, February 26, and April 2, 1993 Analytical results of groundwater samples collected
<br /> from the domestic wells did not report TPH-G or BTEX concentrations above MDLs The analytical
<br />' results of groundwater samples collected during this quarter are summarized in Tables 3 and 5 The
<br /> addresses and owners of routinely sampled domestic wells are listed in Table 4 Copies of the
<br /> analytical laboratory reports are included in Attachment 4 The historical TPH-G laboratory results
<br />' for groundwater samples collected from the monitoring, pumping, and domestic wells are presented
<br /> in Attachments 5 and 6
<br />' CONCLUSIONS AND RECOMMENDATIONS
<br /> Groundwater monitoring data recorded on April 2, 1993, indicates that groundwater levels have
<br /> increased approximately 4 to 6 feet in the monitoring wells at the site The groundwater flow
<br /> beneath the site is generally to the east
<br /> Laboratory results of the samples collected on April 2, 1993, from monitoring wells MW-1, MW-5,
<br /> MW-7, MW-8, MW-9, MW-13, MW-15ABC, MW-16, MW-17ABC, MW-18 through MW-20, former
<br /> pumping wells PW-1, PW-2, and PW-3, and former recovery well RW-1 reported benzene and TPH-G
<br /> concentrations below MDLs in each sample tested Laboratory results of groundwater samples
<br /> collected from domestic wells 8968, 9036, 1912, 9140, 9156, and 9172 on January 22, February 26,
<br /> and April 2, 1993, also reported TPH-G or BTEX concentrations below MDLs
<br /> Based on the results of assessment and remediation activities conducted at the site to date and on
<br /> the results of the soil confirmation boring program conducted at the site in January and February
<br /> 1993, Groundwater Technology will submit a Closijrg Report, dated May 21, 1993, to the San
<br /> Joaquin County Public Health Environmental Division (SJCPHS) The Closure Re ort requests the
<br /> following
<br /> ■ Discontinue groundwater monitoring and sampling of all monitoring wells at the site
<br /> as of July 1, 1993,
<br /> ■ Discontinue groundwater sampling of the nearby domestic wells as of July 1, 1993,
<br /> ■ Conduct appropriate abandonment of all groundwater monitoring, vapor extraction,
<br /> pumping, and recovery wells at the site upon written approval of the SJCPHS and
<br /> the Regional Water Quality Control Board, Central Valley Region
<br /> 1211RO23
<br /> GROUNDWATER
<br /> TECHNOLOGY, INC
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