ARCHIVED REPORTS_XR0010342 - Laserfiche WebLink

Home Browse Search

i i 28 July 1995 AGE-NC-95-0134 Page 5 of 6 Iwas used for this site The model was rerun using the mass of TPH substituted for the mass of xylenes A third and fourth model were run using the data from runs one and two with ground water at a depth of 40 feet (bottom of impacted soil) I 4.0. FINDINGS ' 4 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT ' The relative elevation of the ground water in each well was calculated by subtracting the depth to water from the surveyed relative casing elevation(Table 1) Comparison of the measurements indicate that groundwater at the site rose an average of 4 04 feet between the December 1994 and May 1995 ' monitoring events The ground water gradient was calculated to be 0 0040 ft/ft directed N 56° E (Figure 3) The May 1995 gradient is steeper than previously calculated The flow direction is consistent with previous monitoring events ' 4 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES ' No petroleum hydrocarbons were detected in the samples collected during the May 1995 monitoring The analytical results are summarized in Table 2 The laboratory report and chain-of-custody are ' included in Appendix B ' 43 SESOIL MODELING When all parameters were entered using the best available data, SESOIL, predicted that no ' contaminants would impact ground water No contaminants were predicted to impact ground water for either the second, third or fourth models Appendix C includes SESOIL input data for all four models and output graphs for the first model Output graphs for the second, third and fourth models ' are identical to those of the first model (zero) and therefore were not included The AT 123D model predicts chemical concentrations in ground water at a down-gradient receptor ' well Since no hydrocarbons were predicted to reach ground water, this section of the modeling program was not used I