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3.4.1 Aquifer Characteristic Test Results Slug tests were performed on monitoring wells MW-4, MW-6 and MW-8 to assess the hydraulic properties of the aquifer at the site Since the static water levels in the wells were within the screened zones, only rising head slug test data was collected for analysis The data was analyzed using the "Agtesoly" computer software and the resulting values of hydraulic ' conductivity (K) are presented in Table 2 TABLE 2 ' Aquifer Characteristics Test Results (10130191) San Joaquin County Human Services Agency Building ' Stockton, California Well I D K - Feet/Min K - cm/sec ' MW-4 000147 7 47 x 104 ' MW-6 0001497 7 61 x 10' MW-8 000217 1 10 x 10-3 The K-values range from 7 47 x 10' centimeters per second (cm/sec) to 1 10 x 10-3 cm/sec According to a chart published in "Groundwater" (Freeze and Cherry, 1979), these values are within the range of K values for silty sand to silt in MW-4 and MW-6 and clean sand to silty sand in MW-8 These characteristics are consistent with the lithologic log descriptions of the ' aquifer zones recorded during the well boring These results will be useful in the future if groundwater extraction is required Slug test procedures are presented in Appendix C ' 3.4.2 Tidal Influence Study Results To study the possible influence of diurnal tidal effect on groundwater elevations at the site, WESTON measured groundwater levels during a 4 5 hour period on November 9, 1991 During this period, the tide was receding for 2 71 hours and was rising for 1 8 hours The results of the measurements indicate a total groundwater elevation decrease of 0 18 feet in MW-4 between thigh and low tide on November 9 The total decrease in tidal elevation at the Port of Stockton during the same time period was approximately 1 7 feet (based on tide tables for the Port of ' Stockton) These figures suggest a maximum fluctuation in groundwater levels at the site during the month of November 1991 of 0 22 feet ' Based on an interpretation of these results, hydraulic communication does exist between the unconfined aquifer being monitored at the site and nearby tidally influenced water bodies such as the Stockton deep water channel and the Mormon Slew These results also indicate the tidal ' effect on groundwater elevations at the site could have an impact the groundwater gradient direction at the site and may be a reason for the inconclusive groundwater flow direction data on the site WS/Sic WP 20 o6rozm