Laserfiche WebLink
3 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS <br /> ' Between May 21 and August 22, 2002, the groundwater surface beneath the site dropped an <br /> average of 4 62 feet The groundwater gradient configured using the shallow-constructed wells <br /> ' increased from 0 0012 to 0 0018 foot/foot, and the flow direction shifted approximately 10 degrees <br /> to the north The groundwater gradient configured using the deep-constructed wells also increased <br /> from 0 0015 to 0 0041 foot/foot, and the flow direction shifted approximately 35 degrees to the <br /> ' north Currently, groundwater is at the lowest level since February 1998 Since May 1992, the <br /> groundwater surface has risen approximately 22 0 feet <br /> ' Groundwater from Irrigation Well #2 did not contain detectable concentrations of any of the <br /> gasoline constituent compounds analyzed This represents 10 consecutive quarters of no gasoline <br /> ' compounds in groundwater from Irrigation Well #2 <br /> Between May 21 and August 22, 2002, the concentrations of gasoline compounds in the <br /> groundwater monitoring wells have remained relatively consistent MTBE in groundwater appears <br /> to be limited to the groundwater table to the northeast (downgradient) of the former UST As shown <br /> on an isoconcentration map (Figure 6), the plume of groundwater impacted by MTBE is defined to <br /> the east at MW-4, to the south at MW-2 and VW-1, and to the northeast at MW-8A and MW-813 <br /> Concentrations of MTBE in the wells nearest the former UST source area MW-1 MW-2 MW-3 <br /> VW-1D and VW-2D) have declined significantly Concentrations of MTBE in the wells <br /> downgradient of the source area (MW-5, MW-6 and MW-7) increased initially and appear to have <br /> stabilized <br /> Based on these conclusions, Ramage Environmental recommends that the monitoring well network <br /> continue to be monitored and sampled on a quarterly basis to further monitor plume concentration <br /> and stability At the site, the sources of impacted groundwater have been removed and/or <br /> remediated, the plume of impacted groundwater has been delineated and appears to be stable, <br /> ' and nearby sensitive receptors do not appear to be threatened If concentrations of gasoline <br /> compounds remain stable for one more quarter, the case should be considered for regulatory <br /> closure <br /> The next quarterly groundwater monitoring event is scheduled for November 2002 <br /> 1 <br /> 7 <br />