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Farmington Groundwater Recharge Program STC Work Plan—Hammer Site <br /> 2.2.4. Monitoring Well Drilling and Construction <br /> A single 2.5-inch diameter, poly vinyl chloride (PVC) monitoring well will be installed at the <br /> site. The monitoring well will be used to collect groundwater elevation and groundwater quality <br /> data at the site. Specifically the monitoring well will also be used to observe aquifer response (if <br /> any) during pilot recharge testing. The monitoring well boring will be drilled using HSA, <br /> screened approximately 20 feet across the potentiometric surface (water table), and reach a total <br /> depth of approximately 100 feet below ground surface (bgs). A diagram depicting monitoring <br /> well construction is provided on Figure 4. It should be noted that this diagram represents the <br /> conceptual monitoring well design. Actual monitoring well construction will likely vary due to <br /> encountered site characteristics observed during drilling. Drilling activities and soil lithology <br /> will be recorded on borehole soil description forms and monitoring well construction activities <br /> will be recorded on a well installation record form as provided in Appendices A and B, <br /> respectively. A total of 6 soil samples will be chosen for grain size analysis, two of these from <br /> the coarsest and finest layers encountered during monitoring well drilling. Soils encountered <br /> from ground surface to the total borehole depth will be used to help characterize the geology of <br /> the site. The monitoring well will be developed by the use of a combination of swabbing, <br /> bailing, and purging techniques. These techniques will be documented on the Well Development <br /> Record form provided in Appendix C. <br /> 2.2.5. Survey Monitoring Well and Borehole Locations <br /> Following completion of monitoring well construction, horizontal and vertical coordinates will <br /> be surveyed from the top of the PVC casing. Elevation measurements at the ground surface will <br /> also be recorded. At each of the ten borehole locations, horizontal coordinates and groundwater <br /> surface elevations will also be recorded. <br /> 2.2.6. Water Quality Sampling <br /> Table 2 summarizes constituents to be sampled from groundwater and source water prior to pilot <br /> recharge testing as part of a baseline data analysis. This baseline data will be collected according <br /> to the sampling schedule in Appendix D and will include manual readings, collection of <br /> electronic data, and samples for laboratory analysis. Samples collected for analysis will be <br /> analyzed in the field with the use of field water quality test meters or will be sent for analysis to a <br /> California Certified Analytical Laboratory. Details during the collection of this baseline data <br /> will be recorded on Water Sampling Collection forms as provided in Appendix E. <br /> 2.2.7. Groundwater Elevation Monitoring <br /> Prior to pilot recharge testing, groundwater elevations will be monitored in the newly installed <br /> monitoring well and any other accessible existing agricultural wells located in the immediate <br /> vicinity. The monitoring well will be equipped with a pressure transducer/datalogger that will be <br /> pre-programmed to collect water level and temperature readings at every 30 minutes. <br /> Groundwater elevation data will be collected no less than two weeks prior to and during pilot <br /> recharge testing. <br /> Manual groundwater elevation readings will also be collected at each of the wells as a back-up <br /> measure, in case the pressure transducer/datalogger malfunctions. These manual readings will be <br /> MWH 2-6 July 2004 <br />