The United States has maintained a stockpile of chemical warfare agents and munitions since World War I. The Army leadership has sought outside, unbiased advice on how best to dispose of the stockpile. In 1987, at the request of the Under Secretary of the Army, the National Research Council (NRC) established the Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program (Stockpile Committee) to provide scientific and technical advice and counsel on the CSDP. This report is concerned with the technology selection for the Pueblo site, where only munitions containing mustard agent are stored. The report assesses a modified baseline process, a slightly simplified version of the baseline incineration system that was used to dispose of mustard munitions on Johnston Island. A second NRC committee is reviewing two neutralization-based technologies for possible use at Pueblo. The evaluation in this report is intended to assist authorities making the selection. It should also help the public and other non-Army stakeholders understand the modified baseline process and make sound judgments about it.