Laserfiche WebLink
caused when the well was installed. <br /> There is considerable amount of <br /> additional parking apart from the well. <br /> Trend analysis shows MTBE will not be Trend analysis is based on data collected <br /> detected in MW-20A water samples by during GWE, and may not be applicable <br /> February2011, to natural conditions,without GWE. <br /> Nearby extraction well EW-10A was ND for The wells had two pairs of <br /> MTBE when it was last sampled; therefore contemporaneous sampling results as <br /> MW-20A is probably ND, shown below. Concentrations are in <br /> micrograms per liter: <br /> EW-10A I MW-20A <br /> 11/19/2009 <1(ND) 150 <br /> 12/28/2010 <1 22 <br /> Extraction well EW-10A is approximately <br /> 82 feet obliquely down gradient of <br /> monitoring well MW-20A,and the table <br /> above shows that there is no correlation <br /> between an "ND" in EW-10A and the <br /> contemporaneous contaminant <br /> concentration in MW-20A. <br /> MW-20B Groundwater monitored by the well is ND <br /> for MTBE,this deeper screened well <br /> passes through the contaminated water <br /> monitored by MW-20A; therefore,the <br /> evaluation of issues related to MW-20A <br /> apply to well MW-20B. <br /> Interval through impacted zone has a grout The Nebraska Well Grout Study found <br /> seal between casing and impacted portland cement grouts do not adhere to <br /> groundwater. PVC plastic and a micro-annulus develops <br /> between the cement grout and the well <br /> casing, creating a vertical migration <br /> pathway for groundwater and any <br /> contaminants in the groundwater. <br /> Page 9 of 9 <br />