Laserfiche WebLink
Weston Solutions, Inc. <br /> Remedial Action Work Plan for the San Joaquin County Human Services Agency Site—Stockton, California <br /> NATURE AND EXTENT OF RESIDUAL CONTAMINATION <br /> collected from wells MW-2, MW-2A, and MW-7 during the last monitoring event(December <br /> 2020) were 12,000 µg/L, 0.9J µg/L, and 1.7 µg/L,respectively. <br /> Three water-bearing zones were identified while drilling the boring BH-14 with a deeper zone <br /> encountered at 110 feet and nearly 30 feet of clay between the deeper zone and intermediate <br /> zone above. Well MW-2 is the shallowest well and is constructed with 15 feet of well screen <br /> installed between 30 and 45 feet bgs; however, gravel,possibly from construction activities in <br /> the late 1980s, filled the bottom 7 feet of the well. Wells MW2A, MW3A, MW-6, and MW-7 <br /> have 20 feet of screen installed between various depths ranging from 35 to 63 feet bgs. The <br /> boring for MW-10 was drilled to a total depth of 110 feet bgs with at least 5 feet of clay at the <br /> bottom of the boring. The deeper groundwater is separated from the intermediate zone by at <br /> least 5 feet of clay at well MW-10, which is screened from 94 to 104 feet bgs. The benzene <br /> concentration in the groundwater sample collected from well MW-10 during the most recent <br /> monitoring event(December 2020) was 0.6 J gg/L. <br /> 4-3 February 2021 <br />