HERMISTON -- The incineration plant at the Umatilla Chemical Depot has shut down its last furnace used to destroy chemical weapons.
That means no more emissions from the stacks at the Umatilla Chemical Agent Disposal Facility, and it also means the end of work for 180 employees.
The incineration plant, operated by URS Corp., employed 830 people when the last chemical weapons agent was destroyed in October 2011. Now it has 713. That will be trimmed to 533 Thursday in the plant's largest layoff to date.
About 50 of the employees losing their jobs are transferring to other URS projects, including demilitarization plants for chemical weapons in Colorado and Kentucky, said Hal McCune, spokesman for the Umatilla incineration plant.
Another major layoff is planned in July, when 180 to 200 workers will be laid off as the control room shuts down. The control room continues be to used to coordinate decontamination and cleaning before the plant is demolished.
About half of the workers at the incineration plant commute across the state line from Washington.
The Metal Parts Furnace at the Umatilla Chemical Agent Disposal Facility began its key work when GB nerve agent bomb processing began in September 2005.
During the past seven years and five months, the furnace destroyed more than 1 million pounds of chemical agent and incinerated more than 100,000 munitions.
It was used to burn larger munitions that had been drained, including all the bombs, projectiles, spray tanks and mustard gas containers in the depot stockpile. It also was used to destroy secondary waste, including items from used protective suits, filters and life support air hoses.
It processed almost 1.5 million pounds of secondary waste since the end of chemical weapon incineration operations.
The last load of secondary waste to be processed through the Metal Parts Furnace exited the furnace Friday afternoon, about the same time the project delivered a report to the Oregon State Department of Environmental Quality confirming the shutdown.
Any secondary waste generated as closure work continues will be shipped to the regional landfill 40 miles west at Arlington, Ore., or, if needed, to Veolia Environmental Services in Port Arthur, Texas.
The Metal Parts Furnace was one of four furnaces used to destroy the depot stockpile.
Two liquid incinerators destroyed the bulk of the chemical agent drained from munitions, including GB and VX nerve agent and mustard agent. The Deactivation Furnace System was used to destroy smaller items, including rockets that had been cut up and mines that had been drained.
Closure work at the incineration plant is expected to continue through 2014.