Velimir vesselinov
The regional aquifer beneath Los Alamos National Laboratory (LANL) is a complex hydrogeological system. It is a part of the large-scale regional aquifer within the Espanola basin. Based on the existing water-level data, the general direction of the groundwater flow beneath LANL is predominantly from west to east. The large-scale flow direction is controlled by areas of aquifer recharge to the west (the flanks of Sierra de los Valles and the Pajarito fault zone) and discharge to the east (the Rio Grande and the White Rock Canyon Springs). The Buckman wellfield is located just east of the Rio Grande. Understanding of the hydrogeological characteristics of the aquifer pumped by Buckman wellfield is provided by existing information related to (1) basin geology and hydrostratigraphy, (2) hydrogeologic data (pre- and post- development water levels, pumping drawdowns, spring-discharge rates, etc), (3) ground-surface subsidence, (4) groundwater geochemistry, and (5) naturally occurring stable isotopes. Analyses of these data suggest that the deep section of the regional aquifer pumped at the Buckman wellfield is in a relatively poor hydraulic connection with the Rio Grande and the aquifer beneath LANL. These conclusions can be explained by the pronounced westward-dipping stratification of the Santa Fe Group sediments near the Buckman wellfield which causes the regional aquifer to be highly anisotropic and under confined (artesian during pre-development) conditions. The aquifer properties may provide natural protection of the groundwater resources pumped by the Buckman wellfield.
13th Annual Espanola Basin Technical Advisory Group Workshop and Field Trip
May 13, 2014, Santa Fe Community College, in the Jemez Rooms of the Main Administration Building