ARCHIVED REPORTS XR0006857 - Laserfiche WebLink

Home Browse Search

Y A. Teichert & Son Mobile Equip Shop 103 N. 'E' St. Stockton, CA. SVE Pilot Test Work Plan Feb 1994 excavations indicated elevated concentrations of petroleum hydrocarbons. Prior to soil excavation from the former UST and piping areas, numerous soil borings were advanced and sampled to evaluate the horizontal and vertical extent of product release. Monitoring wells MW-1 through MW-13 were constructed and sampled. A drop in the water table beneath the site has resulted in five remaining wells 11 intersecting the water table. One of these wells is obstructed and sample collection is infeasible. Historical results of groundwater sampling from the four wells indicated that detectable concentrations of petroleum hydrocarbons have occurred in wells MW- 10, MW-11 and MW-13. Historical water level measurements from the five wells indicates that groundwater flow is to the northeast, east or southeast. The locations of existing and proposed wells is illustrated in the Site Map, Figure 1 . 3.0 Technical Approach 3.1 Vapor Extraction Well Construction and Sampling The vapor extraction well will be constructed at the location illustrated in Figure 1 . This location will allow the screened interval of the well to transect the inferred hydrocarbon--impacted zone. This hydrocarbon bearing zone is partially defined by previous work'. Evaluation and laboratory analysis of soil samples collected during DID well construction will provide additional information regarding hydrocarbon concentrations in this zone and in contact with the water table. 3. 1. 1 Soil Boring and Sampling Prior to drilling, the Underground Service Alert Network will be contacted for identification of underground utilities entering the site. These utilities are not expected to affect construction work as the boring will be completed in previously excavated and backfilled soils (Figure 2). The boring will be advanced by 10-inch outside diameter continuous-flight hollow stem augers. Samples will be collected at 5-foot intervals and additional zones of interest. Samples retained for chemical analysis will • be submitted to Sparger Technology, a State-Certified analytical laboratory located in Sacramento, California. We do not expect to collect samples within the former UST backfill, or beneath the water table. Sufficient information exists from previous work to preclude sampling beneath the water table, with it's attendant heaving sands and drilling delays. • 1 Emcon Associates, Report Dated December 15, 1992 2