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sorxi �. Environmental Technology enc _ All monitoring wells were allowed to recover to 95 percent or more of their static water level condition At the time of groundwater sampling, neither free ' product nor sheen was noticed in any of the monitoring wells. Dedicated bailers were used for sampling activities at each of the wells, in order to prevent possible cross contamination ' The six water samples collected were stored in an ice chest maintained at 4 degrees Celsius An appropriate chain of custody was prepared prior to transporting to a State certified laboratory Del Mar Analytical, Irvine, CA ' performed the laboratory analyses All water samples were analyzed for Total Petroleum Hydrocarbons (TPH) as gasoline (Volatile Fuel Hydrocarbons) and Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) following EPA Methods 8015/8020 The test data are presented in Table 2 ' All laboratory analytical results including QA/QC are enclosed with this letter report For the completeness the Table 2 includes the historical data for wells ' MW-1 through MW-6 The groundwater level observations (Table 1) indicated a decrease of ' approximately 4 76 to 5 10 feet during the reporting period (5/ 16/95 to 8/14/95) Regardless of decrease in ground water observed during the reporting period, the water depth in all six monitoring wells have been observed at above the screened intervals of the respective wells for the last two quarters In order to minimize the effects due to this situation, the purging was conducted at the maximum possible pumping rate using the 2-inch GRUNDFOS pump, which was about 4 to 4 5 gpm However, it should be noted that pumping was unable ' to depress the water table below the top of the screen, which was at about 68 to 70 feet BGS for the wells Figure 2 presents the groundwater contour map The general groundwater flow ' direction at the site is towards the north west The gradient for the monitoring event conducted on August 14, 1995 is (-44 65-(-44 90)) / 112 50 = 0 00222 feet/feet, which is consistent with previous quarterly reporting period During the reporting period 5/95 through 8/95, TPH (gasoline) concentrations in MW-1, MW-2, MW-4, MW-5, and MW-6 increased to 8,600, 1,800, 66,000, 540, and 3,500 ppb respectively However for MW-3, a decrease from 88 ppb to non detect was noted, which is consistent with the decrease observed from 2/95 to 5/95 Figure 2 shows the TPH-g concentration contour for the U-HAUL site as of 8/14/95 Likewise, the benzene concentrations for MW-1, MW-2, MW-4, MW-5, and MW- 6 show an overall increase at 1,800, 820, 18,000, 7 3, and 980 ppb ' respectively This is consistent with the increase of the TPH-g concentrations observed historically ' Overall, an increase in the six (6) monitoring wells is evidenced, with the exception of MW-3, during this reporting period MW-4 is found with a significant increase in TPH-g and BTEX observed to date Historically, concentrations were found to be generally fluctuating at the project site 1