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i <br /> b <br /> Geological rechnics liu. Page 3 <br /> Groundwater Monitoring Report <br /> Project No.750.2 <br /> July 22,2003 <br /> Figure 2 shows the location of the well cluster used for calculating vertical groundwater <br /> Lgradient in this report, MW-1 and MW-101. Table 1 shows a Summary of Water Level and <br /> Gradients Slope and Bearing and Table 3 shows the calculated vertical gradients. The <br /> information used in the calculations is shown below. <br /> Vertical gradient calculation formulas are as follows: <br /> • vertical correction for gradient: [(gw gradient slope) x (distance) = vertical correction] <br /> • vertical head: [(head of deep well) - (head of shallow+ correction) =vertical head] <br /> 1 •v vertical gradient: [(vertical head) / (vertical distance) =vertical gradient] <br /> For the June 5, 2003, groundwater measurement, the vertical adient was calculated for the <br /> g �' <br /> MW-1/MW-101 pair. The vertical gradient was positive (a upward direction). However, it <br /> I' was insignificant as head difference between MWA and MW-101 was only 0.03-feet. <br /> �+ Generally, the magnitude of the vertical gradient has progressively decreased since <br /> r February 2001. <br /> As required under AB2886, the depth to groundwater data was submitted electronically to <br /> GeoTracker on June 27, 2003, with confirmation number 1441853165. <br /> i <br /> 1.2 Groundwater Sampling Procedure <br /> On June 5, 2003, Don Light of Del-Tech mobilized to the site to conduct a groundwater- <br /> monitoring event. Del-Tech personnel opened the wells and measured the depth to water <br /> with an electrically actuated sounding tape. The water level reading was recorded to an <br /> accuracy of 0.01 foot. <br /> Stagnant water in the well casing was purged using a Waterra pump and dedicated tubing. <br /> The rate of well purging was monitored. The well was purged of at least three casing <br />� g g p g g <br /> volumes until the groundwater parameters (temperature, conductivity and pH) had stabilized <br /> (Appendix Q indicating that water representative of actual aquifer conditions was entering <br /> the well. Groundwater parameter stabilization was characterized by three successive <br /> readings within 10%. <br /> Before a sample was collected, the well's water level was allowed to recharge to at least <br />' 80% of its initial level. All water removed from the monitoring well and not used as a <br /> sample was placed in a 55 gallon DOT approved container that is properly labeled and <br /> temporarily stored on-site. <br />{ <br /> A Waterra pump and dedicated tubing were used to collect each sample. Extreme care was <br /> exercised while collecting samples to prevent agitation of the water contained in the <br /> j Waterra pump. With minimal sample aeration, water samples were transferred from the <br /> 1 <br /> Il.d <br />