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I I7-Eleven/Stockton 6 March 1991 I ' During this reporting period, ten groundwater-monitoring wells could not be monitored or sampled A prolonged decline in water level has caused monitoring wells MW-2, MW-3, MW--4, MW-5, I MW-10, MW-12, and pumping wells PW2 and PW3 to go dry Monitoring well MW-6 is also no longer in service It was abandoned in September 1986 due to the reconstruction of Thornton Road Monitoring wells MW-11 and MW-14 were not monitored or sampled at Southland's direction The well completion ' data and current status of the monitoring wells at the site are summarized on Table 1 ' The Groundwater Gradient Maps for October, November and December 1990 (Figures 4, 5, and 6) represent the interpreted groundwater-table elevations beneath the site for each of the three ' months of this reporting period The regional groundwater-gradient direction remains to the east as previously reported The gradient magnitude was found to range from about 0 0047 foot-per-foot (ft/ft) ' to 0 0038 ft/ft During this reporting period, no petroleum product odors or separate-phase hydrocarbons were ' found in any of the monitoring wells or pumping wells ' GROUNDWATER SAMPLING AND ANALYSES Sampling of the operational groundwater monitoring wells and nearby domestic wells was performed once during this reporting period Samples were collected in accordance with Groundwater ' Technology's SOPS 9, 10, 11, and 12 (Appendix 8) Groundwater sampling was conducted by first purging water from each well using a clean polyvinyl chloride (PVC) bailer Each well was purged of a minimum of four well volumes of water by hand bailing, unless the wells could be purged dry The ' groundwater was then allowed to recover to at least 80 percent of the original static water level prior to sampling The groundwater samples were obtained using a U S Environmental Protection Agency ' (EPA)-approved Teflon R sampler ' Water samples were collected from selected domestic wells on a monthly basis The domestic wells which were sampled are listed in Table 2 No samples were collected from domestic well number ' 9160 during this quarter, as directed by Southland • GR0UNDX%ATER TECHNOLOG), INC 1