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i. 4 f REGAL 603 8/16/91 conduit. The product is pumped via this "plumbing" network to an above ground 1000 gallon "ConVault" tank. This "ConVault" tank was placed within the secured compound and has been approved by the Stockton City Fire Dept. An automatic shut off switch has been installed to prevent the "ConVault" tank from over spilling if the tarlk becomes nearly full. Approximately 40 gallons of gasoline was recovered. A site visit conducted by WEGE personnel on January 12, 1990 indicated that MW-1 and MW-3 had been depleted of gasoline product. The product recovery system vas removed in February, 1990, and the "ConVault" tank, until September, 1990, was being used for the storage of the purged well water. On May 25, 1990 a water sampled obtained from the "ConVault" indicated that the stored water was free of petroleum hydrocarbons (Table 1 Convault) and this water was later dumped to the sewer after permission was obtained by the Stockton Department if Municipal Utilities (approximately 250 gallons) . During the November 27, 1990 monitoring round, 0.08,' of a clear yellow floating product was again discovered in monitor well MW1. This well was purged until depletion of the product was noted; approximately 1 quart of gasoline was recovered and placed into the 55 gallon drum storing the water "purged" prior to sampling the wells. Product thickness measurements obtained on subsequent site visits have shown only a sheen of product remains in MW1, and also wells MW3 and MW10 have product sheens (showing up after the vapor extraction source test on MW10) . 3.2 SITE CONDITIONS A.a. GROUND WATER: March 29, 1991 The March, 1991 chemical results (sampled 3/29/91) indicate that dissolved benzene in monitor wells MW-2, MW-4, MW-6, MW-S, and MW- 9 substantially exceeds the action level for drinking water of 1.0 ppb, set by the DHS, see Figure 5A and Table 1. Monitor well MW-7 contains a lower benzene value of 5 ppb and monitor well MW5 is below the detection limit (<0.3) for benzene. Monitor wells MW1, MW3 and MW10 contained a sheen of floating product (<0.011 ) . EDB concentrations were below reporting limits for all wells sampled on 5/4/89 (MW-1, MW--2, MW-4, MW-5, MW--6, MW-7, MW-8, and MW-9) so this analysis was not carried on. Strong to moderate bio-odors were also noted along with a grey green coloration of the purged ground water from monitor well MW8. FECAL COLIFORM Monitor wells MW2, MW4, MW5, MW7 and MW8 were sampled r-'i April 8, 1991 for analysis of fecal coliform. These samples werc placed into 500 ml plastic containers and hand delivered that day to Chemtech Analytical Laboratories for Total Coliform and Fecal PAGE 6