SITE INFORMATION AND CORRESPONDENCE

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Mr. James L.L. Barton V January 5, 2004 Page 2 of 3 November 18, 2003: Ground Zero notified by laboratory that the sample collected from EFF on November 17, 2003 contained 9.2 ppb MTBE, but no other detectable VOCs. The sample collected from Cl contained 5,900 ppb MTBE, 780 ppb benzene, and 140 ppb toluene. The treatment system was shut down immediately upon notification of the results. The flow totalizer indicated that 21,685 gallons of water had been treated through the carbon units. November 21, 2003: Pump removed from extraction well and replaced by passive skimmer to remove measurable free product during period of nonoperation. December 1, 2003: Carbon replaced in both units. Supplemental 200-pound carbon unit plumbed in to treatment system after the lag 2,000-pound carbon unit. December 3,2003: Passive skimmer removed from extraction well and pump re-installed and tested. December 4, 2003: Virgin carbon wetted and system pressure tested. System failed pressure test and new gaskets ordered from Carbon Resources. December 10, 2003: Gaskets replaced in both carbon units and system passed pressure test. December 11, 2003: Regional Board and San Joaquin County (EHD) notified and system restarted, witnessed by Regional Board and EHD staff. Bi-weekly sampling program established pursuant to Regional Board requirement. January 2, 2004: Treatment system has operated continuously since December 11, 2003, treating approximately 47,929 gallons of water since carbon replaced. Results of C l, C2, EFF ND for VOCs, including MTBE, for samples collected on December 11, December 15, December 18, December 22, December 26, and December 30, 2003, as well as January 2, 2004. Tables 1 and 2, attached, summarize treatment system flow and analytical data collected to date. ANALYSIS OF BREAKTHROUGH In a follow up letter (October 28, 2003) to the Report of Waste Discharge submitted for the site, Ground Zero stated that carbon usage in the treatment system was estimated at between 37 and 63 pounds per day, depending upon the type of carbon used. At this rate the primary carbon vessel would initially require change out every 31-54 days, based upon then current analytical results from well MW 1 (28,000 ppb MTBE). The carbon usage estimates were provided by several contractors. Carbon usage estimates are attached. Breakthrough of the carbon units actually occurred after approximately 5 days, which is an order of magnitude quicker than estimated. Ground Zero attributes this accelerated breakthrough to two primary factors: 1. Initial testing and start up of the treatment system included testing of the pump placed in the extraction well. Excessive drawdown of the well during initial testing and calibration of the