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k'q KLE1 N FELDER • Petroleum constituents detected in groundwater from the three onsite monitoring wells have decreased from previous sampling events(Table 1) The contaminant plume appears be on the shape of an oval in the vicinity of the former UST and measures approximately 220 feet by I60-feet The plume appears to be contained within the boundaries of the subject site Although the northern extent appears in close proxuruty to the northern property boundary near Industrial Drive Kleinfelder has been conducting on-going semi-annual groundwater sampling since the above- referenced report The following summary details Kleinfelders field activities, findings and conclusions /recommendations for the 1St semi-annual 2002 groundwater sampling event 2.0 FIELD ACTIVITIES On July 3, 2002, Kleinfelder collected groundwater samples from three monitoring wells (MW-1, MW-2, and MW-3) at the project site (Plate 2) 2.1 Measurement of Groundwater Levels During this sampling event, three onsite monitoring wells were opened and allowed to equilibrate After approximately 30 minutes, the depth to groundwater was measured in the three wells using a conductivity-based water level indicator The water level indicator was cleaned prior to use in each well to reduce the potential for cross-contamination Measurements were made to the surveyed mark on the north rim of each PVC monitoring well casing The water level measurements, groundwater elevation and gradient from October 1998 to July 2002 are summarized on the attached Table 2 2.2 Collection of Groundwater Samples After obtaining groundwater depth measurements, Kleinfelder purged and sampled the three monitoring wells MW-1, MW-2 and MW-3 During the purging of the wells, field parameters including temperature, pH, and conductivity were monitored Monitoring wells were purged and sampled according to the protocol described in Attachment A, Section A-4 2 A moderate to strong petroleum-like odor was noted from purge water collected from MW-1 during the sampling event No floating product or sheen was noted during the July 2002 sampling event Copies of the Purge Characterization and Sample Log Sheets are presented in Attachment B 23 Laboratory Analysis The three groundwater samples were transported dunng the sampling event under chain-of- custody control to Agricultural & Priority Pollutants Laboratories, Inc (APPL) of Fresno, California APPL is certified by the California State Department of Health Services (DHS) for the chemical analyses requested The groundwater samples were submitted for the following analyses • • Benzene, Toluene, Ethylbenzene, Xylenes (BTEX) by Method 8015/8021B 20-4439-01 E04/ST02R397 Page 3 of 6 Copyright 2002,KleLnfelder, Inc August 22,2002