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k'q KLEINFELD-ER 5 MONITORING RESULTS The depth to groundwater was measured in each monitoring well included in this event. The depth to groundwater data was converted to elevation in reference to mean sea level for the calculation of groundwater flow direction and gradient. EThe seven groundwater samples were submitted under chain-of-custody procedures to Sequoia Analytical Laboratories of Sacramento, California. Table 2 is a summary of the analytical results for groundwater. For a complete report of the analytical results please refer to the chain-of- custody forms and laboratory analytical reports included in Appendix C. f 5.1 WATER LEVELS On September. 9, 2004, all twenty monitoring wells and three piezometers were sounded for depth to groundwater. The depth to groundwater ranged from 46.74 feet below the top of the well casing(MW-DIS-1 ls)to 55.97 feet below the top of the well casing (MW-DIS-4). The groundwater elevations ranged from —36.00 feet msl to —36.24 feet msl at the site. The groundwater gradient was calculated to be 0.0002 feet/foot, with a general direction of flow towards the east to southeast. A groundwater mound is noted to occur near the central portion of the site where remedial activities are taking place. Plate 3 shows the interpreted groundwater contours. The reported groundwater flow direction has been consistent with the historical data collected at the site Please refer to Table 1 for the recorded groundwater elevations on September 9, 2004 and past monitoring events. 5.2 ANALYTICAL METHODS AND REPORTED RANGES A total of 13 groundwater samples were collected and submitted for analysis. The following is a list of the requested analyses and the reported ranges for groundwater samples obtained from the monitoring wells sampled this quarter; 0 Total Petroleum Hydrocarbons as gasoline by EPA Method 8015M/8021B [non-detect< 50 µg/1 to 160,000 µg/1]; • Benzene by EPA Method 8015NV8021B [non-detect<0.50 µg/1 to 29,000 µg/1]; • Toluene by EPA Method 8015M/802IB [non-detect<0.50 µg/1 to 45,000 µg/1]; • Ethylbenzene by EPA Method 8015M/8021B [non-detect<0.50 µg/1 to 3,600 µg/1]; • Xylene by EPA Method 8015M/802 1B [non-detect<0.50 µg/1 to 23,000 µg/1]; • 1,2-DCA by EPA Method 8260B [non-detect-<0.50 µg/1 to 2,300 µg/l]; << • EDB by EPA Method 8260B [non-detect<0.50 gg/1 to 1,300 gg/1]; • TBA by EPA Method 826013 [non-detect<5.0 µg/1]; _- 12280.M0N/ST04R1610/JZ:1v Page 9 of 13 0 2004,Kleinfelder,Inc. December 10,2004