Laserfiche WebLink
TABLE 3 <br /> Historical TPH-G Concentration Summary (µg/L) <br />' San Joaquin County Human Services Building Site <br />' Sample Date <br /> Well <br /> August 1991' Apni 1993 2nd Quarter 1993 3rd Quarter 1993 4th Quarter 1993 <br />' MW4 520 82 TBAZ TBA TBA <br /> MW-5 ND ND TBA TBA TBA <br />' MW-6 ND ND TBA TBA TBA <br /> MW-7 1700 ND TBA TBA TBA <br /> MW-8 ND 2300 t TBA TBA TBA <br /> I August 1991 data is from the Phase II Groundwater Investigation <br />' 2 TBA - To be added after future sampling events <br /> Based on an interpretation of Figure 3, groundwater beneath the site flows toward a groundwater <br /> surface trough which is aligned southwest-northeast across the site <br />' 4.0 TIDAL STUDY <br /> A tidal influence is present in aquifers in some parts of Stockton where the unconfined water <br /> table aquifer is in hydrologic communication with tidally influenced water bodies such as the <br /> Stockton Deep Water Channel A tidal influence study was conducted on the subject site to <br />' evaluate the possible impact of daily tides on groundwater beneath the site <br /> Groundwater elevation measurements were collected from the five site wells, MW-4 through <br /> MW-8, at 4 55 am and again at 10 30 am on April 15, 1993 The measurement times were <br /> selected based on tidal stage data which showed a maximum difference in tidal stage at those two <br /> times in the Stockton Deep Water Channel Results of the measurements are shown in Table 4 <br />' TABLE 4 <br /> Tidal Study <br />' Groundwater Elevation Measurements <br /> Elevation (MSL) <br /> Well ID <br /> 4 55 am 10 30 am Difference {ft } <br /> MW-4 -3704 -3704 0 <br /> MW-5 -35 80 -35 80 0 <br /> MW-6 -36 56 -36 58 002 <br /> MW-7 -38 36 -38 36 0 <br /> MW-8 -38 11 -38 11 0 <br /> ' WK%RP'rSVcJC IST WP 7 051!8193 <br />