The US DOE through the Mixed Waste Integrated Program, has identified a need to move mixed waste vitrification technology from the laboratory to the field as rapidly as possible. A great deal of work over the last few years has shown the feasibility of immobilizing selected hazardous waste streams in a vitrified product. Lab-scale work has been extended to pilot-scale tests, usually with surrogates of the actual waste. DOE felt that the technology was mature enough to allow demonstration in the field, on actual wastes, with units that would be prototypic of full sized waste treatment equipment. To this end, DOE`s Office of Technology Development sponsored the Westinghouse Savannah River Company (WSRC) to specify, procure, test, and operate a field scale demonstration using mobile equipment. Oak Ridge Reservation was chosen as the initial location for the field demonstration and Martin Marietta Reservation was chosen as the initial location for the field demonstration and Martin Marietta Energy Systems (MMES) tasked with all permitting, site preparation, and field support activities. During September 1993, WSRC used a ``Vendor Forum`` to solicit preliminary proposals for the Transportable Vitrification System (TVS). A number of quality proposals were received and evaluated. A vendor was selected and more » detailed negotiations were completed in August 1994, at which time a contract was signed for the TVS. In parallel, WSRC opened a dialogue with MMES to explore candidate waste streams at the Oak Ridge Reservation for the first TVS vitrification campaign. After some preliminary work, a group of waste water sludges were selected. The first of these to be demonstrated with the TVS will be the West End Treatment Facility (WETF) sludge. This paper describes the development of the specification for the TVS, the design and construction activities to date, and ongoing efforts for permitting and site support. The schedule for field application is also discussed. « less