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In May 2003, SECOR, Inc. submitted a report on the former p Chevron station, entitled Conceptual • .bite Model. That report attempted to show that a plume of contaminated groundwater originating at the Kwikee Foods site has co-mingled with a plume of contaminated groundwater that originated at the Chevron site. EHD is currently reviewing both site models. 3.0 MONITORING PROCEDURES Groundwater monitoring took place on May 22, 2003. Gettler-Ryan Inc. monitored the neighboring Chevron site on the same date and provided water-depth measurements but not laboratory data. After the wells were opened and allowed to equalize with atmospheric pressure, the depth to groundwater was measured with a water level meter and recorded on the Well Monitor Report (Appendix A). A battery-operated purge pump was then used to purge the wells of standing water. Six to 8 gallons of water were purged from the four wells that were to be sampled (KF-1, 2, 3, and 5). The purged water was stored in a 55-gallon drum on site. After purging, water samples were collected with a disposable plastic bailer and placed in 40-m1 vials. The bottles were labeled and logged and placed in a cooled ice chest for Iater transport to Sequoia Analytical Laboratory. The laboratory report and chain of custody form are in Appendix B. 4.0 RES U19TS S 1 rr• �.h ,r. . GJ.1 'X��:l" 4flT'G` :��1a.Q� a G _y�''i. ?6` The static water level on May 22 was nearly identical to the depth on February 20. The depth differed by only a few hundredths of a foot, rising slightly in some wells and falling slightly in others (Table 1). The data in Table 1 and the data from Gettler-Ryan were used to contour the liiezometric surface and interpret the groundwater flow direction, which are illustrated in Figure 3. The piezometric surface was unusually irregular on May 22, with numerous bends in the contours and a variety of hydraulic gradients and groundwater flow directions. The groundwater"trough"that was mapped in the central part of the Kwikee site in February appears to have moved slightly to the east, and a slight "ridge" has formed in the center of the site between KF-2 and KF-3. A second ridge is evident in the southeastern corner of the Chevron site, forming troughs on either side of it. The piezometric surface slopes steeply eastward, northward, and westward from this ridge, and the cone of depression in the vicinity of MW-1 has disappeared. The steep eastward gradient away froze MW-1 may account for the increase in the TPH-gasoline concentrations in MW-6 and KF-3 this quarter, and the steep northward gradient could explain the presence of TPH-g in MW-2, which had been below the detection limit when it was upgradient of MW-1 during most of 2002 (see below). 4