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KEI-P91-0202 .QR4 J April 13 , 1993 Page 2 checked for the presence of a sheen. No free product or sheen was noted in any of the wells during the semi--annual period. The monitoring data collected in this semi-annual period are summarized in Table 1. Water samples were collected from all of the wells on March 26, 1993 . Prior to sampling, the wells were each purged of between 2 and 9 gallons of water by the use of a surface pump. During purging operations, the field parameters pH, temperature, and electrical conductivity were recorded and are presented in Table 2 . Once the field parameters were observed to stabilize and a minimum of approximately four casing volumes had been removed from each well (except for well MW5 , which de-watered after the purging two gallons) , samples were then collected by the use of a clean Teflon bailer. The samples were decanted into clean VOA vials that were then sealed with Teflon-lined screw caps and stored in a cooler, on ice, until delivery to a state-certified laboratory. HYDROLOGY The measured depth to ground water in the wells at the site on March 26, 1993 , ranged between 71. 49 and 72 . 91 feet below grade, except for well MW5, in which the depth to ground water was measured at 61. 71 feet below grade. Similar to previous quarters, the ground water elevation in well MW5 throughout the semi-annual period was significantly higher (approximately 10 feet) than the ground water elevation in all the other wells. This occurrence is considered to be a localized (perched) condition, and thus the data from well MW5 was not used in calculating ground water contours. The water levels in all of the wells have shown net increases ranging from 3 . 45 to 3 . 61 feet since October 12 , 1992 , except for well MW51 in which a net decrease of 0. 24 feet was observed. Based on the water level data gathered during the semi-annual period, the ground water flow direction appeared to be predominantly to the south (varying from the south-southwest to the south-southeast) , as shown on the attached Potentiometric Surface Maps, Figures 1, 2 , 3 , and 4 . The flow direction has been predominantly to the south (varying from the southwest to the southeast) since December of 1991 (four consecutive quarters) . The average hydraulic gradient across the site on March 26, 1993 , was approximately 0. 002 . ANALYTICAL RESULTS The ground water samples were analyzed at Sequoia Analytical Laboratory and were accompanied by properly executed Chain of Custody documentation. The samples were analyzed for total petroleum hydrocarbons (TPH) as gasoline by EPA method 5030/modi- fied 8015, and benzene, toluene, xylenes, and ethylbenzene by EPA