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Bank of Stockton-Western Lift <br /> Groundwater Monitoring Plan <br /> November 8,1995 <br /> Page 2 <br /> • November 1995 -Conduct Field Work <br /> • . December 1995- Prepare and Submit Monitoring Report <br /> PURGING AND SAMPLING METHODS <br /> The groundwater level will be measured in each well before any purging of that <br /> well occurs. An groundwater level measuring tape with an electronic sensor <br /> will be used. This tape has an accuracy to the nearest one-one hundredth of a <br /> foot. If floating product is suspected, then one other event must take place <br /> before the well is purged and that is to lower a bailer into the well to determine <br /> the product/water interface. The presence of floating product will affect water <br /> elevations and sampling protocol. <br /> The groundwater purging and sampling procedures are as follows. The well is <br /> unlocked and opened. <br /> Stagnant water in the well casing is purged using a stainless steel bailer belayed <br /> with a servo actuated electric reel. The rate of well purging will be monitored. <br /> Each well will be purged of at least three casing volumes and then purged until <br /> the groundwater parameters (temperature, conductivity, and pH) had stabilized <br /> (Table 1) indicating that water, representative of actual aquifer conditions, is <br /> entering the well. Groundwater parameter stabilization was characterized by <br /> three successive readings within 10%. <br /> Before a sample was collected, the well's water level was allowed to recharge to <br /> at least 80% of it's initial level. All water removed from each monitoring well <br /> and not used as a sample, was placed in a 55 gallon DOT (Department of <br /> Transportation 17-H) approved container that is properly labeled and <br /> temporally stored on-site. <br /> A bailer is then used to collect each sample. Bailer cleanliness is assured by <br /> collecting a bailer blank (pouring distilled water through the bailer and <br /> collecting it in a VOA vial) prior to collecting the analytical sample. Before and <br /> in between uses, all sampling .equipment was washed using a portable steam <br /> cleaner. <br /> The domestic water well on the adjacent Cutter Lumber site will be sampled by <br /> turning on the pump and allowing the well to flow for about 3 minutes. After <br /> being allowed to flow, a sample cock located on the housing of the electric pump <br />