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are provided in the attached Figures 3 through 12. Construction of the monitoring wells will be completed under the direct supervision of a California State licensed Engineer or Geologist. For the purposes of bid preparation, CONTRACTOR shall assume terminal depth of wells to be approximately 50 feet below ground surface (bgs), but actual depth will vary as discussed below. The CONTRACTOR will hand auger the top five feet to check for any unidentified underground utilities. Soil borings will be advanced with a truck-mounted drill rig equipped with at least an 8-inch diameter hollow stem auger. CONTRACTOR shall collect soil samples every 5-feet via Standard Penetration Test (SPT) sampler for lithologic classification by a Kleinfelder geologist or engineer based on the Unified Soil Classification System (USCS). The soil borings will be advanced approximately 15 feet into groundwater (estimated total depth 50 feet). The CONTRACTOR will supply all capabilities for advancing deeper wells if groundwater is not encountered within the estimated construction design or encountered at a depth that would require additional borehole advancement. If a clay layer at least 5 feet thick is encountered below the first encountered groundwater, the boring will be terminated. All equipment used in the drilling and construction procedures will be cleaned and/or decontaminated with a steam cleaner or Liquinox® cleaning solution before and after use at each site. 2.3. Monitoring Well Installation and Development Upon reaching terminal depth, the on-site geologist or engineer shall determine final well construction details based upon the lithology. The CONTRACTOR shall construct the monitoring well using new two-inch diameter Schedule 40 polyvinylchloride (PVC) screen, blank casing, and screw-on bottom cap. The well screen will be 0.020-inch slotted PVC. The estimated volume of filter pack, bentonite, and cement shall be calculated by the CONTRACTOR prior to installation and compared to actual material volumes used. The actual material volumes used shall be recorded on a field record form. In accordance with San Joaquin County and Stanislaus County Well Standards (documents attached), the CONTRACTOR shall install a filter pack consisting of#3 sand through the hollow stem auger (has) in the annular space between the well screen and borehole wall via tremie pipe or equivalent, from the bottom of the borehole to one (1) foot above the screened interval. To prevent bridging of filter pack material and ensure complete filling of the annular space, the CONTRACTOR will regularly check the top of the filter pack and shall surge the well 20191132.001A/SAC22P142176 Page 3 of 5 July 1, 2022 ©2022 Kleinfelder