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Site Background Information Eckert Cold Storage,Manteca,CA Page 7 of 8 No separate phase petroleum or sheen was noted in the wells during the July 8, 2005 monitoring event, but a moderate hydrocarbon odor was noted in the groundwater inspection sample collected from MW-8. Water levels were collected from all eight of the site monitoring wells on July 8, 2005. The average groundwater elevation was approximately 2.04 feet lower than the previous sampling event conducted on March 9, 2005. The groundwater gradient estimated with a three-point construction using wells MW-3, MW-4, and MW-6 was approximately 0.00 11 ft/ft toward the west. Historically, the groundwater gradient direction at the site has been variable but generally to the northwest. During the previous quarter (March 9, 2005), the groundwater gradient direction (northwest) was consistent with the predominant historic gradient direction.This represented a shift back from the two previous quarterly monitoring events which indicated a northerly flow (December 2004) and a northeasterly flow (September 2004). The gradient direction estimated during the second quarter monitoring event (west on July 8, 2005) was not consistent with recent historic gradient directions. The estimated gradient magnitude (0.0011 ft/ft), however, indicated a very gentle water table slope; consequently the flow direction may not be significant relative to transport of site groundwater contamination. The groundwater samples collected from the monitoring wells were analyzed for BTEX, TPH-G, and selected gasoline oxygenates/additives including MTBE. As mentioned above, prior to the December 2004 monitoring event, historic laboratory analytical results of groundwater samples collected from MW- 5 indicated generally very low contaminant concentrations. Laboratory analytical results of samples collected from MW-5 in December 2004, January 2005, and March 2005, however, indicated higher contaminant concentrations (but with a decreasing trend in contaminant concentrations). Laboratory analytical results collected from MW-5 during the July 8, 2005 monitoring event indicated that the trend was continuing -- contaminant concentrations had returned to very low levels. Conversely, prior to the December 2004 monitoring event, historic laboratory analytical results of groundwater samples collected from MW-8 indicated generally elevated contaminant concentrations. Laboratory analytical results of samples collected from MW-8 in December 2004, January 2005, and March 9, 2005 indicated lower contaminant concentrations relative to the historic results. The laboratory analytical results collected from MW-8 during the July 2005 monitoring event indicated that contaminants in MW-8 had returned to the relatively higher concentrations consistent with samples from the well collected prior to December 2004. Condor conducted third quarter 2005 groundwater monitoring activities on September 22, 2005. Monitoring wells MW-5 and MW-8 were sampled during the third quarter. As mentioned above, Condor had recommended quarterly monitoring of MW-5 along with MW-4 and MW-8 in the First Quarter Groundwater Monitoring Report. After reviewing Condor's recommendation, Mr. Harlin Knoll of the SJCEHD verbally requested quarterly monitoring of MW-5 and MW-8 provided that Site monitoring wells MW-1 and MW-4 are sampled on annual basis in the fourth quarter(December). No separate phase petroleum or sheen was noted in the inspection sample collected from wells during the third quarter monitoring event, but a moderate hydrocarbon odor was noted in the inspection samples collected from both. Water levels were collected from all eight of the site monitoring wells on September 22, 2005. The average groundwater elevation was approximately 0.34 foot lower than the previous sampling event conducted on July 8, 2005. The groundwater gradient estimated with a three-point construction using wells MW-3, MW-4, and MW-6 was approximately 0.00 14 ft/ft toward the northwest, which is generally consistent with historical groundwater gradient directions. The groundwater samples collected from the monitoring wells were analyzed for BTEX, TPH-G, and selected gasoline oxygenates/additives including MTBE. As mentioned above, prior to the December 2004 monitoring event, historic laboratory analytical results of groundwater samples collected from MW- 5 indicated generally very low contaminant concentrations. Laboratory analytical results of samples collected from MW-5 in December 2004, January 2005, and March 2005, however, indicated'higher contaminant concentrations (but with a decreasing trend in contaminant concentrations). Laboratory