Laserfiche WebLink
During the third quarter, the highest groundwater elevation was 3.00 feet relative to <br /> mean sea level (ft MSL) measured in well MW-10, and the lowest groundwater elevation <br /> was -1.41 ft MSL measured in well MW-28. Hydraulic gradients were variable. The <br /> predominant groundwater flow direction was southwesterly. <br /> During the fourth quarter, the highest groundwater elevation was 2.90 ft MSL measured <br /> in well MW-10, and the lowest groundwater elevation was -1.51 ft MSL measured in <br /> well MW-28. Hydraulic gradients were variable. The predominant groundwater flow <br /> direction was southwesterly. <br /> 3.2 VERTICAL GRADIENTS <br /> CRA calculated vertical gradients using groundwater elevation data collected from well <br /> pair MW-26, screened from 5 to 29.5 feet below grade (fbg), and DW-2, screened from 55 <br /> to 60 fbg. The gradient calculations are presented in Table 6. The vertical hydraulic <br /> gradients were upward during both sampling events. <br /> 3.3 SPHS <br /> SPHs have historically been measured in nine wells: MW-1, MW-10, MW-11, MW-13, <br /> MW-15, MW-16, MW-17, MW-22, and MW-24. No SPHs were observed in the <br /> monitoring wells during the second half of 2011. Historical measurable SPH values are <br /> presented in Table 3. <br /> 3.4 ISOCONCENTRATION MAPS <br /> Because most of the wells were sampled during the third quarter 2011, CRA used those <br /> groundwater monitoring data to prepare the isoconcentration maps. The following <br /> constituents of concern were contoured and are shown on Figures 4 through 8, <br /> respectively: total petroleum hydrocarbons as diesel (TPHd), total petroleum <br /> hydrocarbons as gasoline (TPHg), benzene, methyl tertiary-butyl ether (MTBE), and <br /> tertiary-butyl alcohol (TBA). <br /> 241729(32) 3 CONESTOGA-ROVERS B ASSOCIATES <br />