COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Lii. Environmental Site Assessment Report 20 E.Lindsay Street,Stockton,CA June 24,2004 Page 3 dumping of wastes were noted. A concrete slab approximately 13 feet by 9 feet in size with two pipes filled with concrete is located at the rear of the site (Figure 2,Appendix A). 3.0 DIRECT PUSH BORING FIELD PROCEDURES A subsurface investigation program was designed and implemented to sample soil beneath the site for possible contaminants. 3.1 SITE PREPARATION A drilling permit application was prepared by Condor and submitted to the SJCEHD for six proposed direct push borings. Condor received the drilling permit prior to initiating any fieldwork. The proposed boring locations were marked with white paint and Underground Service Alert (USA) was notified 48 hours in advance of the fieldwork to locate and identify underground utilities in'and near the work area. The SJCEHD was notified of the fieldwork schedule 72 hours in advance. 3.2 DIRECT PUSH BORING PROCEDURES A Condor geologist was on site to supervise the work. Prior to commencement of fieldwork, a tailgate safety meeting was held and a site-specific Health and Safety Plan was discussed with, and presented to, all field personnel for their signatures. The investigation included the advancement of six direct push borings (GP-1, GP-2, GP-3, GP-4, GP-5, and GP-6) to collect soil samples on June 10, 2004, using a Geoprobe® boring and sampling system. Boring GP-3 was advanced immediately south of the oil/water separator located inside the building. Boring GP-5 was advanced southwest of the concrete slab located in the rear of the property. The boring locations are shown in Figure 2, Appendix A. The direct push borings were hydraulically advanced using a two-inch diameter conical bit. The bit and associated push rods were thoroughly cleaned before each borehole was advanced using laboratory-grade, non-phosphate detergent and deionized water and double-rinsed with deionized water. Upon completion of the drilling and sampling, the boreholes were backfilled with neat cement. Cuttings from the borings and equipment rinsates were placed in DOT-approved 5-gallon buckets, sealed, labeled, and left on site pending receipt of laboratory analytical results. 3.2.1 Soil Sampling Borings GP-1 through GP-6 were advanced to a depth of approximately 15 feet bgs. Soil samples were collected from each boring with a 1.75-inch diameter, 4-foot long core barrel fitted with a clean, single use, polyethylene liner. The soil sampling equipment was cleaned prior to collecting each sample using laboratory-grade,non-phosphate detergent and deionized water and double rinsed'with deionized water. During the sampling, the core barrel was driven in 4-foot intervals.The sample liners were extracted from the core barrel and used for geological logging and field observations. Portions of the soil samples were placed in polyethylene bags and screened with a photoionization detector (PID) for the presence of volatile hydrocarbon vapors. Soil samples collected from the borings were logged according to the Unified Soil Classification System (USCS). Geologic logs were prepared containing field observations including soil type, PID measurements, and the presence of staining or odor. The geologic logs are included in Appendix C. ia CONDOR