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kTJ KLE1NFELDEP monitoring wells will be to monitor for a potential perched groundwater zone between the settling pond and the Delta Mendota Canal and in the vicinity of the California Aqueduct. The well borings will be advanced usinga truck-mounted drill rig g equipped with 8-inch hallow stem augers. During the advancement of the well borings, soil samples will be collected at 10- foot intervals and at each significant lithologic unit for lithologic classification only. Discrete E samples will not be collected in coarse gravel and cobble zones. Lithologic classification will be based on the Unified Soil Classification System. Currently, based on our experience, we do not anticipate encountering groundwater during advancement/installation of these three monitoring wells. Three 2-inch PVC monitoring wells will be installed in each of the three borings located near the Delta Mendota Canal and California Aqueduct. DSS has reported that the depth of the Delta Mendota Canal invert is approximately 20 feet below ground surface. Kleinfelder assumes the California invert depth is approximately the same. Therefore the three shallow monitoring wells will be screened from approximately 15 to 35 feet below ground surface (bgs). The proposed screened interval is estimated to span a depth of approximately 5 feet above and 15 feet below the Delta Mendota Canal and California Aqueduct invert depth. The monitoring wells will be generally constructed as described for monitoring wells in Attachment B. The monitoring well locations and elevations will be surveyed by DSS, so that subsequent water level sounding data can be utilized in determining groundwater flow directions and gradient as described in Attachment B. { Task E03—Monitoring Well Development and Well Survey O tional Task A minimum of forty-eight hours after installation, the three new monitoring wells may be developed to remove sediment from the bottom of each monitoring well, remove sediment laden water, and to increase the hydraulic radius of the monitoring wells. Kleinfelder anticipates the three shallow wells will be dry and therefore will not need to be developed. However, if water is present, the wells will be developed based upon approval of Task E03. Development will be performed using a pump and/or bailer as generally described in Attachment B. Kleinfelder understands the top of casing of each of the three proposed well and three existing production/irrigation wells will be surveyed by DSS personnel for location and elevations. Elevations will be surveyed to the nearest 1/100'h of a foot. Task E04—Well Samplin2 and Monitoringf DEEP IRRIGATION/PRODUCTION WELLS Water level measurements will be made in three existin irri anon/ roduction wells (Plate 1 at the � beginnin of the sam ling round rior to ur in ands lin he wells. The;depth to groundwater will be measured in each well according to the protocol described in Attachment B. The depth to water measurements will be converted to relative groundwater elevations with respect to mean sea level or a local benchmark by subtracting them from the surveyed casing elevations. 20-YPO-212R/2000P29112000W027 Page 3 of 7 2000 Kleinfelder,Inc. August 16,2000