SITE INFORMATION AND CORRESPONDENCE

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CLEARWATER G a o u r, i N C. Environmental Services 4.0 RESULTS 4.1 Water Level Monitoring Data Groundwater elevations ranged from -12.94 to -13.35 feet mean sea level (MSL) on March 14, 1996, indicating that groundwater has risen 3.6 to 3.7 feet since the December 1995 monitoring event. The depth to water in each well was measured from the top of the well casing, which had been surveyed relative to MSL. Water level data are presented in Table 1, and groundwater elevation contours are presented on Figure 3. The local groundwater flow is estimated to be to the east and northeast at,an approximate gradient of 0.8% (0.008 ft/ft), which is consistent with the gradient estimated during previous monitoring events. 4.2 Groundwater Analytical Results TPHg and BTEX were not detected at or above laboratory reporting ,limits in the groundwater samples collected from monitoring wells MW-1 or MW-2. MTBE was not detected in samples from any of the five monitoring wells. Although the sample from MW-5 contained 100 parts per billion (ppb) TPHg, BTEX was not detected. It should be noted that TPHg was also detected in MW-5 samples during the third and fourth quarter sampling events in 1995. Prior to then, TPHg „ .had not been detected.in.groundwater samples from MW-5. TPHg concentrations were 80 ppb and 100 ppb in samples collected from monitoring wells MW-3 and MW-4, respectively. Benzene concentrations were 11 ppb in the sample from monitoring well MW-3, as well as in the sample from MW-4. Recent analytical results indicate that benzene concentrations in samples from MW-3 and MW-4 have decreased over the past year. A summary of analytical results is presented on Table 1 and on Figure 4. The laboratory report and chain-of-custody form are attached as Appendix B. D-103 IQ96 3 April 4, 1996 i ii I