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Y `.r Interim Remediation Work Plan 419 S.Main Street,Manteca,CA June 25,2003 and the first quarter of 2003, and to address concerns the SJCEHD had regarding the site. In a letter Page 3dated May 29, 2003, the SJCEHD directed the submittal of a work plan to install, test, and operate an interim remediation system and a work plan to adequately define the lateral and vertical extent of the contamination plume at the site. The SJCEHD also agreed with Condor's recommendation to destroy damaged monitor wells MW-4 and MW-5, and to install a monitor well to replace MW-4. This work plan addresses the installation of a groundwater pump and treat system for interim remediation, and the destruction of MW-4 and MW-5 and the installation of a replacement monitor well for MW-4. Detailed site background information is included in Appendix B. 3.0 EXTRACTION WELL INSTALLATION PROCEDURES r This section includes a description of the site preparation, the drilling procedures, and the extraction well installation. 3.1 SITE PREPARATION Condor will complete a well installation permit application and obtain the required permit from the SJCEHD prior to the commencement of fieldwork. Condor will schedule and coordinate all field activities through the property owner (Boyett) and the SJCEHD. The proposed drilling location will be marked with white paint and Underground Service Alert (USA) will be notified at least 48 hours in advance of the +.+ fieldwork to locate, identify, and mark underground utilities in and near the work area. However, because companies contacted by USA may not identify utilities past private property lines and into the site, it is the responsibility of Boyett to locate, identify, and mark any utilities on their property. V 3.2 DRILLING PROCEDURES Prior to commencement of fieldwork, a tailgate safety meeting will be held and a site-specific Health and `r Safety Plan will be discussed with, and presented to, all field personnel for their signatures. One groundwater extraction well will be installed at the site. Laboratory analytical results of groundwater samples collected from the site monitor wells indicate the highest concentrations of MTBE have been found in the samples collected from MW-1 and MW-7. To capture contaminants that have migrated off-site in the westerly downgradient direction, in addition to the contaminants remaining in groundwater at the site, Condor proposes to install the extraction well near the location of MW-7. The proposed location of the extraction well is shown on Figure 2 in Appendix A. The extraction well boring will be drilled using 10-inch outside diameter, continuous-flight, hollow-stem auger. The hollow-stem auger and other down-hole equipment will be decontaminated by steam cleaning prior to drilling. The extraction well boring will be drilled to approximately 20 feet below the water table. It is anticipated the total depth of the well boring will be approximately 40 feet bgs. All drilling activities will +•� be observed by a Condor geologist. Drill cuttings from the extraction well boring will be logged according to the Unified Soil Classification i► System (USCS). Descriptions of soil types encountered and any other pertinent field observations will be recorded on boring logs. Cuttings will be placed in a polyethylene bag and checked with a photoionization detector (PID) for the presence of volatile hydrocarbons. All visual observations and PID measurements will also be noted on the boring logs. L i� CONDOR L