ARCHIVED REPORTS_XR0012734 - Laserfiche WebLink

Home Browse Search

f X69. E'§ I I -nr "wr"; T�c'a r a a�� 1 �rn,5'' e u` 5 4. .� 1 1 ::a� [a..a�. �`• y li &fit E i SIERRA wells were identified in the well survey within one-half mile of the site(Figure 3,Appendix A), Well owners, well owners'addresses, well location and well use are shown in Table 1 (Appendix 13). i Two of the wells identified in the well survey, a domestic well and a municipal well are potentially downgradient of the site. These wells are both more than one-quarter mile southeast of the site. The closest wells are seven monitoring wells located on the Lincoln Center property,one well west of the Lincoln Center property. and three San Joaquin County wells located in Gettysburg Place northwest to southwest of the site (Pfigure 2, Appendix A). These wells are located upgradient, cross-gradient and downgradient of the site. e r 2.SUBSURFACE INVESTIGATION i On July 24, 25,27,29 and August 5, 1990, four soil borirgp-i were drilled at the site by Soils Exploration Services of Vacaville, California. The borings were drilled to determine the presence or absence of hydrocarbons in soil beneath the site, Monitoring wells were installed in the four borings to evaluate ground water quality, and to determine the ground water gradient beneath the site, Monitoring well MW-2 was installed south of the southern pump islands in the presumed downgradient direction. Monitoring well MW-3 was installed northeast of the former underground tank location(in the northeast comer of the site). Monitoring well MW-4 was installed southwest E, of the existing underground tanks and monitoring well MW-5 was drilled next to the existing waste oil tank. The boring/monitoring well locations are shown in Figure 4, (Appendix A). The monitoring wells were constructed using 4-inch diameter,flush-threaded schedule 40 ` PVC blank casing and 0.020 slotted well screen. Twenty(20)ft of well screen was used in each of the monitoring wells with the top of the well screen placed approximately six to seven feet above the static water level to allow for seasonal ground water fluctuation. Page 5