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Mr.Harlin Knoll April 4,2001 USA Service Station No. 65 Page 2 On May 4 and 5, 2000, Stratus supervised the installation of two groundwater monitoring wells (MW-9 and MW-10) to assess the lateral extent of petroleum hydrocarbon impact southwest of the site. These monitoring wells were developed on May 16, 2000. Stratus also supervised the installation of one air sparge well (AS-1) in the vicinity of the active pump islands. Monitoring well MW-5, located in the shoulder of Lower Sacramento Road, was abandoned on May 5, 2000, at the request of City of Lodi due to a proposed widening of Lower Sacramento Road. All existing monitoring wells (with the exception of MW-7) and the newly installed MW-9 and MW-10 were surveyed on August 4, 2000 by Morrow Surveying, Inc. The location of the wells is shown on Figure 2. Stratus oversaw the construction and installation of a SVES in July and August 2000. A system startup and source test were conducted on August 15, 2000. The results of the startup and source test were reported to San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) on October 19, 2000. SCOPE OF WORK The SVE system on site is connected (via 2-inch laterals) to monitoring wells S-1, S-2 and MW-8. A cumulative mass of approximately 185.6 pounds of TPHG has been extracted and abated by the SVE system. The system is operating as designed. Depth to groundwater on site has varied between 36 and 40 feet bgs. Screen intervals in wells S-1, S-2 and MW-8 begin at 26, 26 and 28 feet bgs respectively. The available screen interval above the groundwater table in these three wells ranges between 8 and 12 feet. Review of the local geology (Pinnacle RAP, January 26, 1999) indicates a silty clay layer exists approximately between 32 and 40 feet bgs. Sand and gravel lies both above and below this silty clay layer. Evaluation of soil samples collected during the UST replacement activity indicates that petroleum hydrocarbon impact to soil exists beneath the UST complex (15 to 30 feet bgs). Petroleum hydrocarbon impact to soil away from the tank complex was predominantly detected in the capillary fringe. The existing vapor extraction wells address the petroleum hydrocarbon impact to the capillary fringe. The proposed SVE well will target this vadose zone in the sand and gravel unit above the first encountered groundwater and below the UST complex. Stratus proposes to drill and install one 4-inch diameter SVE well with 20 feet of screen within the vadose zone. The scope of work has been subdivided into Tasks 1 through 4. C:Troject Files%USA Gasoline%00651Workplans165-workplan.doc 5TRATU5