ARCHIVED REPORTS XR0001735 - Laserfiche WebLink

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.4pp/!ed Ge�Systern.� 4191•E Power Ian Road, Sacramento, CA 95826 f9161 452-2901 • FREMONT • IRVINE • HOUSTON • BOSTON • SACRAMENTO e CULVER CITY o SAN JOSE December 20, 1990 1015gdem AGS 86091-8 Mr. Glenn Dembroff Ultramar Inc. 525 West Third Street Hanford. California 93230 Subject: Third Quarter 1990 Sampling of Ground-Water Monitoring Wells at Beacon Service Station No. 502, 35 North Cherokee bane, Ladi, California. Mr. Dembroff: This report presents the results of the third quarter 1990 groundwater sampling that Applied GeoSystems conducted at Ultramar's request at the subject site (see the Site � + Vicinity Map, Plate P-I). The purpose of this sampling program is to monitor the concentration of dissolved hydrocarbons in ground water at the site. Work included measuring depths to water, sampling ground water for subjective and laboratory analyses of hydrocarbons, and evaluating the ground-water gradient beneath the site. The locations of the monitoring wells are shown on the Generalized Site Plan, Plate P-2. Present Ground-Water ,SaIgpling On September 25, 1990,a geologist from Applied GeoSystems measured water levels in the monitoring wells (see Table 1). These water levels were used to construct the Potentiometric Map, Plate P-3. The measurement from monitoring well MW-1 indicated that the ground-water surface has dropped below the total depth of the well. The direction of ground-water flow beneath the site on September 25, ?990, was evaluated to be to the southwest; the gradient was evaluated to be 0.0037. We collected ground-water samples from each monitoring well except well MW-1 and examined the samples for floating product, sheen, and other subjective evidence of hydrocarbons. No subjective evidence of hydrocarbons was observed in any of the monitoring wells. The geologist then collected ground-water samples from eachmonitor ing well for laboratory analysis. Water purged from the wells was placed in 55-gallon drums approved for this use by the Department of Transportation and stored temporarily at the site pending removal by Ultramar.