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Problem Assessment wade Plan MUS=Multi-Carnpus Regici al Center + January 23,2003 Page-3- additional groundwater investigation portion of the recommendations, but requested the evaluation'of the feasibility of at least two remedial options for the site. 4 Ei r 73.0 DIRECT PUSH BORING FIELD PROCEDURES This section includes a description of the site preparation and direct push boring procedures. j • 3.1 SITE PREPARATION Condor will complete boring permit applications and obtain the required permits prior to the fieldwork. Condor will schedule and coordinate all field activities through CSUS. The proposed boring locations will :be marked with white paint and Underground Service Alert (USA) will be notified at least 72 hours in :advance of the fieldwork to locate and identify underground utilities in and near the:work area. Because ` companiescontacted by USA may not identify utilities past private property lines and into the site, :'however, it is the responsibility of CSUS to identify any site utilities. 3.2 DIRECT PUSH BORING PROCEDURES f 'Prior to commencement of fieldwork, a tailgate safety meeting will be held and a site-specific Health and E :Safety Plan will be discussed with, and presented to, all field personnel for their signatures. Five pairs of k 'direct push borings will be installed at the site. One pair wi11 be installed on the downgradient side of the source area. Three pairs will be installed downgradient of the source area. One pair will be installed tupgradient of the source area. Condor anticipates that additional borings may be necessary based on field �i E,observations of the proposed borings. Field observations for the borings will include inspection'of an r ,.. .aliquot of the water sample for odor and organic vapor with a photoionization detector(PID). The proposed Nboring pair locations are shown in Figure 2, Appendix A. Laboratory analytical data for soil and groundwater samples collected during previous investigations are presented in Table A and Table B, i "Appendix B. The first boring of each pair will be a CPT boring that will be used to log the subsurface geology,at the 'location of each pair. The CPT borings will be advanced to an approximate depth of 100 feet below ground 'surface (bgs). It is possible that the borings will be terminated at refusal before reaching a depth'of 100 11 feet. An electric piezocone will be pushed downward into the subsurface by the CPT rig. Measurements of cone bearing, sleeve friction, and dynamic pore water pressure will be measured at approximately two-inch intervals to provide a nearly continuous hydrogeologic log of the subsurface. Ile 'After all of the first borings of each pair are completed, additional direct push borings will be ins td at 4 each pair location. The additional borings, located within two feet of the first, will be used to'collect discrete interval groundwater samples. One groundwater sample will be collected from the first groundwater encountered in each boring. Condor anticipates that two or three .other discrete depth groundwater samples will be collected at each boring pair location based on the information in the five geologic logs. _ r • .: Groundwater samples will be collected using a push type groundwater sampler. The sample has a'seale d, retrievable stainless steel screen. The sampler will be pushed in a closed position to ilie desired sampling interval. The sampler push rod will then be retracted exposing the inlet screen. Groundwater will flow hydrostatically from the formation into the inlet screen. The groundwater sample°will be collected by lowering a stainless steel bailer through the hollow push rods and into the sample screen. The groundwater �a CONDOR