The Blue Grass supercritical water oxidation system, originally intended for treatment of a specific plant secondary waste, will no longer be used. Chemical weapons will continue to be destroyed at the Blue Grass plant.

“Based on the performance of the system during testing and the events encountered, there are operational concerns,” said Dr. Candace Coyle, site project manager, Blue Grass Chemical Agent-Destruction Pilot Plant. “After careful consideration of many studies, reports, observational data and discussions with community representatives, the Assembled Chemical Weapons Alternatives program executive officer made the decision to ship hydrolysate off site.”

The supercritical water oxidation, or SCWO, system, was designed to use a high-temperature and pressure process to treat hydrolysate, the liquid product of the chemical weapons destruction process. During testing, multiple issues were discovered that raised reliability concerns to the point a decision was necessary to determine the path forward for the system, Coyle said.

“Part of the decision included the potential for transitioning the SCWO to another Army organization for evaluation, development and testing for other uses in the future,” Coyle said. “Just identifying causes of and working through the current issues could take three to five years, and we need to stay on track to destroy the chemical weapons by the congressionally mandated deadline of Dec. 31, 2023.”

Instead of being treated through the SCWO system, it is planned for hydrolysate to be shipped to a licensed and permitted hazardous waste treatment, storage and disposal facility, Coyle said. There will be an opportunity for public comment on the permitting process for off-site shipment, likely in 2021.

The current SCWO workforce is already being transitioned to other project duties, with several remaining to support hydrolysate loading operations.