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SECOND QUARTER 2002 REPORT KWIKEE FOODS 2081 Country Club Boulevard Stockton, California July 5,2002 EXECUTIVE SUMMARY Groundwater monitoring took place on May 24. The depth to groundwater was measured with a water level meter and water samples were collected from all seven monitoring wells. A battery- operated purge pump was used to purge the wells of standing water, which was stored in DOT- approved drums on site. As directed by San Joaquin County Environmental Health Division in its January 15 letter to the Responsible Party, samples were analyzed for Total Petroleum Hydrocarbons as gasoline, volatile aromatic hydrocarbons (BTEX), six gasoline oxygenates, 1,2- dichlorethane, ethylene dibromide, and total lead. Due to remediation activities at the Chevron site at 2103 Country Club Boulevard in the early part of 2002, a groundwater "sink" developed there during the first quarter. This reversed the local groundwater flow direction, and flow was radial toward that site. Remediation activities were suspended during the latter part of the first quarter and the first half of the second quarter, and groundwater again began flowing eastward beneath the Kwikee Foods site. The water table remained somewhat depressed beneath the Chevron site, however, maintaining radial flow at that site. As a result, a very low groundwater "divide" was present beneath Franklin Street when water depths were measured in May. Concurrent with the return to eastward groundwater-flow beneath Kwikee Foods, hydrocarbon concentrations rose in three wells (KF-3, KF-5, and KF-2). Total Petroleum Hydrocarbons as gasoline increased from 280 to 620 ppb in KF-3 and from 190 to 410 ppb in KF-5. Benzene concentrations increased from 39 to 120 ppb and from 41 to 66 ppb, and MTBE increased from 66 to 150 ppb and 7.6 to 24 ppb. The xylene concentration increased above the detection limit in KF-I and KF-2, and MTBE also rose slightly in KF-2. Combined, the laboratory data imply, that the dissolved-phase gasoline plume migrated eastward slightly during the quarter in response to the return to eastward groundwater flow. During the last three years, we have repeatedly concluded that hydrocarbons in the groundwater beneath Kwikee Foods migrated there from the former Chevron site as a result of the prevailing eastward hydraulic gradient. The February 2002 laboratory data substantiated this conclusion, by showing that concentrations decline when remediation at the former Chevron site causes reversal of the hydraulic gradient and leads to westward groundwater flow. The May 2002 laboratory I