AbstractThis article presents the results of demonstration of Geosafe Corporation's in‐situ vitrification (ISV) technology at the Parsons Chemical/ETM Enterprises Superfund site in Grand Ledge, Michigan. The primary focus of this article is on the EPA's Superfund Innovative Technology Evaluation (SITE) Program assessment of the sixth melt. A total of eight melts were performed during this project. This demonstration was part of the SITE Program Demonstration (USEPA, 1994), which helped develop innovative hazardous waste treatment technologies, especially those offering permanent remedies for contaminated Superfund and other hazardous waste sites. The demonstration results are not only applicable to this particular project, but are also indicative of other Geosafe project experiences and demonstrate the current state of the ISV technology. The demonstration included two phases. In the first phase, the ISV technology was used to treat the Parsons contaminated soil. In the second phase, post‐testing and analysis were conducted about one year after the ISV technology was applied to confirm that the vitrification was completed and that no contamination migration had occur