Modeling of ground-water flow in the Culebra Dolomite at the Waste Isolation Pilot Plant (WIPP) site: Interim report

Abstract

This hydrogeologic modeling study has been performed as part of the regional hydrologic characterization of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The study resulted in an estimation of the transmissivity distribution, hydraulic potentials, flow field, and fluid densities in the Culebra Dolomite Member of the Permian Rustler Formation at the WIPP site. The site characterization studies are being conducted as part of the evaluation of the suitability of bedded salt of the Salado Formation for isolation of defense transuranic waste. The objectives of this report are to document the hydrogeologic data base for the Culebra dolomite at the WIPP site (including Culebra elevations, transmissivities, fluid densities, freshwater heads, and hydrologic stresses during the period 1981 to 1986); develop a conceptualization and modeling strategy for describing ground-water flow in the Culebra; present the calibration approach and results for simulating ground-water flow in the Culebra under undisturbed hydraulic conditions and during the transient period (1981 to 1986) resulting from shaft activities and well tests (in particular, the H-3 multipad pumping test); present the results of sensitivity analyses to assess the impact of vertical fluxes to the Culebra on the freshwater head and fluid-density distributions; and present the resultsmore » of calculations and analyses to assess the impact of double-porosity flow on the transient behavior of the simulated hydrogeology in the Culebra dolomite. 118 refs., 98 figs., 26 tabs.« less