Publications

Using multi-node computers for assessing flow and transport at the waste isolation pilot plant, Carlsbad, NM

Lowry, T.S.; Beauheim, Richard L.

The Waste Isolation Pilot Plant (WIPP) in southeast New Mexico has been developed for underground disposal of transuranic waste in halite beds of the Permian Salado Formation. Managed by the Department of Energy, the WIPP has been operational since March 1999. The most important water-bearing unit above the Salado Formation is the Culebra Dolomite Member of the Rustler Formation (Culebra), which lies about 200 m below ground surface and 400 m above the repository. Here, two investigations are conducted using parallel processing that address separate issues in the Culebra that may have an effect on the groundwater flow field in the area surrounding the WIPP site. The first investigation looks at current and future potash mining in the upper Salado Formation, within and outside the WIPP boundary. Potash mining causes subsidence of the Culebra, resulting in higher transmissivities that may change regional groundwater flow patterns. A Monte Carlo approach is used to characterize model uncertainty. The second investigation assesses possible causes for an observed water-level rise in 17 monitoring wells in the Culebra over the last 10 to 15 years. Two possible scenarios for the rise in heads are: (1) leakage into the Culebra of refining-process water discharged onto potash tailings piles, probably through subsidence-induced fractures and/or leaky boreholes; and (2) leakage into the Culebra of water from units above or below the Culebra through poorly plugged and abandoned boreholes. Leakage rates for each scenario are inversely modeled and calibrated to linearized drawdowns of 12 monitoring well hydrographs. Copyright ASCE 2005.