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C L E A kWA'T-E R ' G R O U P • Env;ranra[nlal SeFWcis site Initial inquiries suggested, and it was latter confirmed, that there is an existing fuel transport ' line in the area of the site, and that it is currently filled with nitrogen gas Based on this information, Clearwater recommended additional investigation along South Fresno Avenue to ' better understand the distribution of contamination and possible contribution from potential off- site sources The results of this phase of investigation were presented in Clearwater's Well ' Installation and Groundwater Monitoring Report-First Quarter 1999 On March 8, 2000, Clearwater supervised the completion of one hydropunch, six soil borings, ' the destruction of MW-5, and built three additional wells MW-5B, MW-7, and MW-8 (Figure 2) All three wells were placed on the downgradient portion of the plume to help determine the ' downgradient extent of contaminants The hydropunch was performed in the former UST location to assess the vertical extent of hydrocarbons Three soil borings were performed to ' define the lateral extent of soil and groundwater contamination on the northeastern portion of the site and assess possible off-site sources The results of this phase of investigation confirmed the verticle and horizontal extent of both sorbed- and disolved-phase contamination at the subject site The results of this phase of investigation were submitted in Clearwater's Additional Assessment and Quarterly Groundwater Monitoring First Quarter 2000 Based on the significant sorbed- and dissolved-phase contaminant concentrations beneath the ' site, Clearwater recommended the testing of engineered in-situ remedial technologies at the site In order to effectively test these technologies, on February 22, 2002, Clearwater supervised the ' installation of one 4-inch dual-phase extraction well and one 2-inch air sparge well at the core of the contaminant plume ' On March 12, 13 and 14, 2002 Clearwater performed groundwater extraction (GWE) feasibility testing, combined GWE and soil vapor extraction (SVE) feasibility testing, and GWE/SVE with ' air sparge (AS) feasibility testing, respectively Details on methods and results can be found in Clearwater's Well Installation and Feasibility Testing Report dated May 9, 2002 1 I ' ZB178C CAP 3 November 20,2002