Laserfiche WebLink
� i <br /> MONITORING WELL INSTALLATION WORKPLAN <br /> WESTERN LIFT <br /> 3430 S. E1 Dorado Street <br /> BACKGROUND <br /> The site is located in a flat industrial area south of Stockton <br /> (Figure 1 - Location Map, 7. 5 Minute Stockton West Quadrangle, USGS <br /> Topographic Map Series, 1976) . The facility consists of a large <br /> warehouse and adjoining office and exterior fenced parking/delivery <br /> area (Figure 2 - Site Plan) . <br /> Three underground tanks were removed from the delivery area in June <br /> of 1991. Gasoline contamination was detected in three of the seven <br /> soil samples collected from the excavation, indicating that an <br /> unauthorized release of hydrocarbons had occurred and that an <br /> assessment of the site was r-aquired. Sample results were summarized <br /> in the Site Contamination Workplan submitted by Geological Audit <br /> Services to San Joaquin county Environmental Health Division on <br /> July 24 , 1991. <br /> The assessment of the site was performed in two phases. Each phase <br /> • consisted of overexcavation followed by the collection and analysis <br /> of soil samples from the walls and floor of the excavation. The <br /> excavation phases and sampling are described in the Preliminary <br /> Investigation and Evaluation Report (PIER) submitted to the SJEHD <br /> on 11 December 1991. <br /> On 1 May 1992, backfilling of the excavation was completed. The <br /> excavation was backfilled to grade with pea gravel and will be <br /> covered with asphalt to match the surrounding surface. <br /> PROPOSED WELL LOCATIONS <br /> On 1 June 1992 , a single monitoring well was installed immediately <br /> north of the former tank excavation. On 4 June 1992 a water sample <br /> was collected from the well and analyzed for total petroleum <br /> hydrocarbons (TPH as gasoline and diesel) and purgeable aromatics <br /> (BTE&X) . TPH contamination was detected in the water sample and the <br /> SJ PHS/EHD required that two additional monitoring wells be <br /> installed to determine the lateral extent of the water <br /> contamination. The results of the initial monitoring well <br /> installation and sampling were detailed in a report submitted the <br /> SJ PHS/EHD dated 26 June 1992 . <br /> . To define the groundwater contamination plume, GeoAudit proposes to <br /> install two additional monitoring wells on the referenced property. <br /> one well will be installed south of the warehouse, near the <br /> southern boundary of the property (near the Manna Pro facility) . <br />