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i SCOPE OF WORK This section describes the proposed scope of work for this investigation. The investigation will include drilling'and sampling one groundwater monitoring well to determine if hydrocarbon impacted groundwater exists beneath the site. Appendix B describes Brown and Caldwell standard procedures for this work scope. Figure 2 presents the proposed location of monitoring well MW-1. The monitoring well will be constructed of 2-inch-diameter poly vinyl chloride (PVC) casing and is anticipated to be approximately 25 feet deep. Soil samples for lithologic identification and possible laboratory analysis will be collected at 5 foot intervals in the borehole. Up to 3 soil samples will be submitted to the laboratory for analysis of total petroleum hydrocarbons as gasoline (TPH-G), and benzene, ethylbenzene, toluene, and xylenes(BEM using U.S. Environmental Protection Agency(EPA) Method 5030/8020/8015 Modified. Upon installation, the well will be developed and a groundwater sample will be collected. The groundwater sample will be analyzed for TPH and BETX using EPA Method 503018020/8015. In addition, the groundwater sample will be analyzed for methyl-tertiary-butyl- either(MMT-).using EPA Method 5030/8020/8015 as requested in the May 6, 1996 County letter. This well will be sampled on a quarterly basis for a period of two quarters. At the end of two quarters,the future need for this well will be evaluated by the County based on the sampling data. The soil generated during the installation of this well will be stockpiled on site on and covered withF lastic. In addition to the borehole soil sampling analytes, stockpile samples will be analyzed for Soluble Threshold Limit Concentration for lead by EPA Method 6010/7000 series. If; based on field instrument readings, the hydrocarbon concentration of the soil stockpile sample exceeds 800 milligrams per kilogram, the stockpile sample will be analyzed for reactive sulfides and cyanides by EPA Method 9010, corrosivity (pH)by EPA Method 9045, Ignitability(flash point) by EPA Method 1010 for disposal characterization purposes. Groundwater(well development water and decontamination water) will be temporarily stored on site. The stored water will be transported off-site and properly disposed of by an ARCO subcontractor. PROJECT SCHEDULE The fieldwork will require one day to complete. This time frame includes drilling, installing, 4 development, and sampling the groundwater monitoring well. The starting date will depend on County approval of the work plan and on driller availability. A summary report in letter form will be completed within approximately 6 weeks after field work is complete. The report will include a description of field methods, results of laboratory analysis of soil samples, and conclusions. The report will be submitted to ARCO for review, and the final report will be �h provided to the County. Use or disclosure.,of data continued on this sheet is subject to the restriction specified at the beginning of this document. 24171REP0RTS\N;WLr1.D0C