[en] The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) repository that has been developed to demonstrate the safe and permanent isolation of transuranic radioactive wastes in a deep geologic site. It is located in 650 m below the surface in a bedded salt formation, and is designed to hold approximately 175,500 cubic meters of waste. Compliance with the regulations has become the principal focus for the Project. The scientific baseline is an important and integral part of the CCA, as it provides the foundation for conducting total system performance assessment calculations for comparison with applicable standards. The activities required to support the scientific baseline are being pursued in parallel to minimize the time required to collect, analyze, interpret and fully incorporate the results into the CCA. The DOE has shifted its approach to demonstrating compliance with the applicable regulations from a paradigm of a series of broad investigations to a new paradigm of highly focused activities conducted in parallel. The success of this approach will be assessed by the EPA when the application is critically reviewed