Y-12 Groundwater Protection Program Monitoring Well Inspection and Maintenance Plan

This document is the third revision of the 'Monitoring Well Inspection and Maintenance Plan' for groundwater wells associated with the US Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee. This plan describes the systematic approach for: (1) inspecting the physical condition of monitoring wells at Y-12; (2) identifying maintenance needs that extend the life of the well and assure well-head protection is in place, and (3) identifying wells that no longer meet acceptable monitoring-well design or well construction standards and require plugging and abandonment. The inspection and maintenance of groundwater monitoring wells is one of the primary management strategies of the Y-12 Groundwater Protection Program (GWPP) Management Plan, 'proactive stewardship of the extensive monitoring well network at Y-12' (BWXT 2004a). Effective stewardship, and a program of routine inspections of the physical condition of each monitoring well, ensures that representative water-quality monitoring and hydrologic data are able to be obtained from the well network. In accordance with the Y-12 GWPP Monitoring Optimization Plan (MOP) for Groundwater Monitoring Wells at the Y-12 National Security Complex, Oak Ridge, Tennessee (BWXT 2006b), the status designation (active or inactive) for each well determines the scope and extent of well inspections and maintenance activities. This plan, in conjunction with the above document, formalizes the GWPP approach to focus available resources on monitoring wells which provide the most useful data. This plan applies to groundwater monitoring wells associated with Y-12 and related waste management facilities located within the three hydrogeologic regimes: (1) the Bear Creek Hydrogeologic Regime (Bear Creek Regime); (2) the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime); and (3) the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek Regime encompasses a section of the Bear Creek Valley (BCV) immediately west of Y-12. The East Fork Regime encompasses most of the Y-12 process, operations, and support facilities in BCV east of scarboro Road. The Chestnut Ridge Regime is directly south of Y-12 and encompasses a section of Chestnut Ridge that is bound to the west by a surface drainage feature (Dunaway Branch) and by Scarboro Road to the east. The GWPP maintains an extensive database of construction details and related information for the monitoring wells in each hydrogeologic regime in the 'Updated Subsurface Database for Bear Creek Valley, Chestnut Ridge, and parts of Bethel Valley on the US DOE Oak Ridge Reservation (BWXT 2003a). A detailed description of the hydrogeologic framework at Y-12 can be found in the GWPP Management Plan (BWXT 2004a)