CORRESPONDENCE_2011 - Laserfiche WebLink

Home Browse Search

1 VF MIEW • The following sections provide a detailed description of the work that will be completed for this project. All field work will be completed in accordance with the Health and Safety Plan (Attached). 3.3 BOREHOLE DRILLING AND HYDROPUNCHTM 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, drive the HydropunchTM samplers, and construct the permanent monitoring wells. Based on geologic and groundwater elevation data from wells MW -5, MW -8, and SB -1, each borehole is proposed to be drilled to a depth of 80 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 Department of Environmental Health 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. 3.3.2 Drilling, Soil Sampling, and Logging Methods Prior to beginning drilling operations and between each location, all drill rig and sampling equipment will be properly decontaminated using high-pressure wash and steam -cleaning equipment. Monitoring well boreholes will be drilled using an 8 -inch diameter hollow stem auger. In the unsaturated zone, samples will be collected at five-foot intervals using a California -modified split -spoon sampler. At a minimum, geologic logging of boreholes will address the following elements: ■ Borehole designation and location. 7 2011-0115 CHSL EMP Workplan Geo -Logic Associates Revision 1 -August 24, 2011