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Site Background Information Eckert Cold Storage,Manteca,CA July 26,2004 Page 4 of 5 The average groundwater elevation was approximately 0.26 feet lower on June 5, 2003, than the previous sampling event conducted on March 28, 2003. The groundwater elevation contours estimated with the depth to water measurements indicated the groundwater gradient was generally towards the northwest. The groundwater gradient estimated using MW-4, MW-6, and MW-7 was 0.0024 ft./ft, towards the northwest, and was generally consistent with historical groundwater gradients estimated for the site. Condor conducted the third quarter 2003 groundwater monitoring event at the site on September 2 and 3, 2003. Groundwater samples were collected and submitted for laboratory analyses from monitor wells MW-4,MW-8, and domestic well DW-1. No separate phase petroleum was noted in the wells, but a slight petroleum odor was noted in groundwater recovered from MW-8. The groundwater samples collected from the monitor wells and the domestic well were analyzed for BTEX, TPH-G, and selected gasoline oxygenates/additives including MTBE. Laboratory analytical results for the September 2 and 3, 2003, monitoring event were generally consistent with historical laboratory analytical results. The average groundwater elevation was approximately 2.37 feet lower on September 2, 2003, than the previous sampling event conducted on June 5, 2003. Water level data from monitor well MW-7 was not included in the September 2, 2003 figures. Water level measurement of monitor well MW-7 was obstructed by a root mass in the casing. The root mass in monitor well MW-7 was removed on September 3, 2003 by using a small diameter auger. The groundwater elevation contours estimated with the depth to water measurements indicated the groundwater gradient was generally towards the northwest. The groundwater gradient estimated using MW-4, MW-5, and MW-6 was 0.0020 ft./ft. towards the northwest, and was generally consistent with historical groundwater gradients estimated for the site. Condor conducted annual groundwater monitoring on December 12, 2003 during the fourth quarter 2003 groundwater monitoring event at the site. Groundwater samples were collected and submitted for laboratory analyses from annually monitored wells MW-5 and MW-7; as well as from quarterly monitored wells MW-4, MW-8, and domestic well DW-1. No separate phase petroleum, sheen, or odor was noted in the field inspection samples collected from the wells. Monitoring well MW-5 was observed to have a damaged monument, and the well casing appeared to be broken just below the ground surface. Groundwater samples collected from the monitoring wells and the domestic well were analyzed for BTEX, TPH-G, and selected gasoline oxygenates/additives, including MTBE. Laboratory analytical results for the December 12, 2003, monitoring event were generally consistent with historic laboratory analytical results. The average groundwater elevation was approximately 0.10 feet lower on December 17, 2003 than the previous sampling event conducted on September 2, 2003. The groundwater elevation contours estimated with the depth to water measurements indicated the groundwater gradient was variable but overall towards the northwest. The groundwater gradient estimated with a three-point construction using wells MW-3, MW-4, and MW-6 was 0.002 ft./ft. towards the northwest, and was generally consistent with historic groundwater gradients estimated for the site. Condor recommended that monitoring well MW-5 be repaired and resurveyed, or destroyed. s