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Limited Subsurface Site Investigation Results Report Moore Petroleum Bulk Plant,5491 F Street,Banta,San Joaquin County,California Page 4 groundwater monitoring well MW-17. August 16, 2004 - The SJCEHD directed in a letter that an addendum be made to the Workplan for a Limited Subsurface Site Investigation, dated January 14, 2004, in order to define the vertical extent of contamination. Apex submitted Workplan Addendum Letter for a Limited Subsurface Investigation, dated June 2, 2004. September 2004 - Apex installed and tested an SVE system with activated carbon adsorption as the control device. In addition, Apex installed an ozone generator system for eventual ozone sparging. Results from the SVE startup were reported to San Joaquin Valley Air Pollution Control District (SJVAPCD) in the letter Source Test Report, dated November 11, 2005, December 6-8, 2004 - Apex supervised the drilling of nine ozone sparge wells (OS-2 through OS-10). Results of the ozone well installations are reported by Apex in Interim Results Report for Ozone sparge wells, dated March 4, 2005. The ozone system began full time operation on February 17, 2005. MONITORING WELL INSTALLATION ACTIVITIES Prior to drilling, drilling permits were obtained from the SJCEHD. Underground Service Alert was contacted for identification of buried utilities at or entering the project site from the public right-of-way. For safety purposes, the first 5-feet of each boring was hand augered. On October 31, 2005, Apex supervised the installation of four groundwater monitoring wells (MW-13, MW-14, MW-16 and MW-17) (Figure 2). Drilling for well MW-15 has been postponed until the receipt of the Union Pacific Railroad Company's right-of-entry agreement. The wells were installed by Woodward Drilling Co., Inc., of Rio Vista, California using a hollow stem auger rig. The wells were installed in an attempt to delineate the vertical and horizontal extent of petroleum hydrocarbons in soil and groundwater at the site in the upgradient direction. Well Construction Details Groundwater monitoring wells MW-13, MW-14 and MW-16 were installed as 2-inch diameter Schedule-40 PVC monitoring wells to a total depth of 20-feet bgs. The well casings were screened with a 0.020-inch slotted screen from 5-feet below ground surface (bgs) to total depth. The groundwater monitoring wells were constructed with #3 Monterey sand filter pack to 1-foot above the screened interval followed by a foot and a half of bentonite seal and Portland cement to the surface. Well MW-17 was installed as a 2-inch diameter Schedule-40 PVC monitoring well to a total depth of 25-feet bgs and was screened from 10-feet bgs to total depth. Well MW-17 was constructed with#3 Monterey sand filter pack to 2-feet above the screened interval followed by 2-feet of bentonite seal and Portland cement to the surface. All wells are protected with locking expansion caps and flush-mounted traffic-rated vault boxes. All work was accomplished in accordance with the Apex standard operating procedures (SOP) included in Appendix B. A table of well construction details is presented in Table 1.