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Section 2 Groundwater Monitoring Well Installation 2.1 MONITORING WELL LOCATIONS AND RATIONALE The purpose of groundwater monitoring is to provide a measurement of compliance with regards to the State Antidegradation Policy and Regional Board Order 90-313,with respect to wastewater treatment and disposal activities. An effective groundwater monitoring network will provide at least one clearly"up-gradient" and a minimum of two"down-gradient"wells within each respective project area, including the wastewater treatment ponds, and the offsite wastewater storage pond/wastewater disposal area located approximately 1500 feet south southwest of the WWTF. Furthermore,them nitoring network should be designed to allow for normal seasonal fluctuations in groundwater elevation and horizontal groundwater gradient direction,while taking into account water quality effects associated with dilution, such as wells of large diameter and/or with excessive lengths of well screens. Additional wells are sometimes required when strong seasonal changes in gro ndwater gradient are suspected and when hydrogeologic boundaries, or other condition are encountered. Such wells must be designed and located to provide representative samples of groundwater beneath the wastewater treatment, storage, and disposal sites and not create a vertical conduit for contamination of deeper groundwater. Figures 1, 2, and 3 thus illustrate the locations of proposed wells positioned such to augment the exiting groundwater monitoring network and provide an effective means of measuring facility compliance with regards to potential groundwater degradation. These well locations were chosen based largely on expected groundwater flow direction and known accessibility constraints. The location of these wells take into account both locally observed groundwater flow direction at the existing wastewater treatment ponds and regional groundwater elevations obtained from the DWR and should provide adequate monitoring of groundwater both up and down gradient of potential anthropogenic influences associated with wastewater treatment, storage, and disposal. These monitoring locations should also provide a measure of the spatial variability in groundwater quality up gradient and in the near vicinity of the WWTF. 2.2 EQUIPMENT DECONTAMINATION PROCEDURES At a minimum,decontamination will comprise of a hot water pressure wash of the drilling equipment. As a precaution against cross-contamination between boreholes,the drilling equipment will be decontaminated prior to the start of drilling of the first monitoring well and between each successive monitoring well borehole. March 2006 Lockeford CSD 2.1 Groundwater Monitoring Well Installation Workplan