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If VOCs are detected in samples from the initial well locations, replacement "step out" well locations will be considered at locations that are further beyond the locations identified on Figure 3 using the groundwater equipotential data and chemistry results to identify a direction and distance for the replacement well. If the sampling results indicate the need to construct a replacement well, then the County will provide the RWQCB with analytical data, rationale, and a plan showing the proposed location(s) of the replacement well along with a revised schedule for construction, sampling, and reporting. The followingsections provide a detailed description of the work that will be completed for p p this project. All field work will be completed in accordance with the Health and Safety Plan (Attached). 3.3 BOREHOLE DRILLING AND SAMPLING All drilling and well construction will be completed in accordance with procedures summarized in Department of Water Resources (DWR) Bulletin 74-90, under the direct supervision of a California Professional Geologist and in accordance with a permit granted by San Joaquin Department of Environmental Health. Gregg Drilling has been retained by the County to provide drilling and well construction services, and is licensed in the State of California to drill the exploratory boreholes, install the temporary wells, and construct the permanent monitoring wells. Based on geologic and groundwater elevation data from wells MW -5, MW -8, and SB -1 and the temporary wells drilled as part of this project, each borehole is proposed to be drilled to a depth of 75 to 90 feet; however, actual final depths will be determined based on field data. Since drilling operations will not take place near residential areas, or beyond typical working hours, noise abatement services are not proposed for this project. However, temporary borehole protective cover or steel sheeting will be placed on the entry hole during breaks in the drilling process. In the event that a borehole needs to be abandoned during the drilling program, the hole will be sealed by placement of neat cement grout (with 5% bentonite by weight) using tremie pipe and positive displacement techniques in accordance with San Joaquin County Environmental Health Department requirements. 3.3.1 Well Permitting Upon approval of this workplan, borehole/well construction and abandonment permits will be obtained through the San Joaquin County Environmental Health Department. Copies of the permits will be included in the final EMP report that will be provided to the RWQCB at the conclusion of the project. 7 2011-0115 CHSL EMP Workplan Geo -logic Associates Revision 2—January 11, 2012