WORK PLANS - Laserfiche WebLink

Home Browse Search

{ City of Stockton it TL# 394-0192-01 September 16, 1994 Page 4 to assess the downgradient condition of ,groundwater (Drawing 2) . The exact locations of the borings will be determined in the field based on the locations of underground utilities and other site improvements. Soil samples will be collected at five-foot intervals beginning at 20 feet BSG. A Twining geologist will log soil samples according to the Unified Soil Classification System and will screen the samples for evidence of contaminants. The screening will consist of visual observation for staining or i3unusual fluids, unusual odors, and head space analysis with a p' hotoionization detector ' (PID) for the presence of organic vapors. PID operation and procedures for the performance of head space analysis are described in our SOPS contained in Appendix A. Two soil samples from each boring will be preserved and retained for laboratory analysis. After completion of the soil sampling, the borings will be completed as two-inch diameter monitoring wells. Soil cuttings . generated during drilling will be storedion site in U. S. Department of Transportation (DOT) -approved 55-gallon drums. Disposal of the drill cuttings will be determined based upon the ' results of the laboratory analyses. Disposal of the drill cuttings will be the responsibility of the client.,, 4. 1.2 Monitoring Well Installation I� The monitoring wells will be constructed 'of 2-inch diameter schedule 40 polyvinyl chloride (PVC) well casing and 0. 02-inch machine slotted well screen. Casing and well iscreen will be flush threaded. Based on an estimated depth to groundwater, the screened section will extend from approximately 20- to 40 feet BSG. Lonestar #3 washed sand, or its equivalent, will be placed from the bottom of the boring to approximately two feet above the top of the machine slotted casing. Approximately three feet of bentonite pellets will be placed on top of the filter pack, and the remaining annular space will be _filled with a bentonite neat cement grout containing three to five percent. The wells will be sealed with a locking PVC cap. A traffic rated steelvault will be installed flush with the ground surface and secured-t place with concrete. i Drilling and well installation activities will be supervised by a Twining geologist. The Twining geologist will1,,be working under the direct supervision of a California registeredlgeologist. Twining understands that the San Joaquin County Environmental Health Department (SJCEHD) requires oversight of grouting activities and that no charge will be applied for one' hour or less for each permit. . Twining anticipates completing the grouting for well installation within the specified time frame. ', 1