Laserfiche WebLink
Lou <br /> 7-ElcvenfStockton <br /> April, 1988 16 <br /> The results of the laboratory analyses performed on the <br /> water samples obtained from the monitoring and pumping wells <br /> indicate the highest dissolved contamination levels to be in the <br /> vicinity of the former pump island and extending north toward Mw- <br /> 11• The t,,-al petroleum hydrocarbon-as-gasoline plume decreased <br /> in areal extent throughout the reporting period and was present <br /> only near the former pump island on the last sample round on <br /> March 24, 1988. <br /> RECOVERY WELL INSTALLATION <br /> Due to the low efficiency of pumping well 3 (PW-3) , a new <br /> well was installed to increase hydraulic control on the contami- <br /> nant plume. Recovery well 1 (RW-1) was installed on February 1, <br /> Nes and was placed 'approximately 15-feet northeast of PW-3 <br /> (see <br /> Figure 2) . Prior to installing RW-1, a soil boring was drilled <br /> near the location of the new recovery well to more fully define <br /> the stratigraphy and to collect soil samples for sieve. analyses. <br /> The results of the sieve analyses were used to select the optimum <br /> slot-size and filter-pack for recovery well construction (Appen- <br /> dix III - Laboratory Results) . <br /> WThe boring for the new recovery well was drilled with a 24- <br /> inch-diameter bucket rig to a depth of 57-feet below grade. The <br /> recovery well is constructed with 30 feet of 12--inch-diameter, <br /> M.. low-carbon steel well screen (0.015--inch slot) and 25 feet of <br /> blank casing. A well pack was placed in the annulus consisting <br /> of Monterey F-105 filter sand from completion depth to 24--feet <br /> rr� ��L CROUNUIVATFR <br /> L...OJL TWINOWICY.INC <br />