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record of well development will be recorded by Dames and Moore personnel for each well and maintained <br />on file. <br />B.3 GROUNDWATER SAMPLING PROCEDURES <br />Following well development, groundwater samples will be collected in accordance with pertinent <br />applicable sampling protocols, details of which are presented below: <br />B.3.1 Static Water Level Measurement <br />Before sampling, the static water level will be measured in each monitoring well using an electric <br />water level indicator. Measurements will be recorded and repeated until at least two consecutive depth <br />readings are within 0.01 feet. Water level data will be recorded to the nearest 0.01-foot from a reference <br />point marked on the top of the well casing. All reference points will be surveyed by a licensed surveyor. <br />Before and after each use, the measurement device will be thoroughly rinsed with deionized water. <br />B.3.2 Well Evacuation <br />Monitoring wells will be purged by bailing or with a portable submersible pump prior to sample <br />collection in order to obtain samples which represent groundwater in the formation, rather than water <br />standing in the well casing. Monitoring wells will be purged until a minimum of three casing volumes <br />is removed from the well and the field-measured temperature, pH, and specific conductivity are stabilized. <br />As used here, the term "casing volume" means the volume of water being stored inside the well <br />casing at the time the well is visited for purging and sampling. One casing volume (CV) is calculated <br />using: <br />CV = (pi r2 d) (7.48 gals/f 3) <br />where: <br />PROP06.005 <br />pi = 3.14; <br />r = the radius measured from the center of the well to the inside surface of the well <br />casing (feet); and <br />d = the depth of the column of water standing in the well (feet). <br />B-5 <br />DAMES Si MOORE