The incineration plant at the Umatilla Chemical Depot plans to lay off 100 people Thursday, two weeks before demolition is set to begin, URS Corp. announced Tuesday.
URS, which holds the contract to build, operate and decommission the plant, employed 830 people when the last of the chemical weapons stored at the depot were destroyed in late 2011. About half of those employees commuted across the state line from the Tri-Cities and nearby communities.
This week's layoff primarily will affect operations and maintenance employees who worked inside the soon-to-be demolished Umatilla Chemical Agent Disposal Facility, as well as 18 employees of Southwest Research Institute, the subcontractor that operates the project's laboratory.
After this week's layoff, 165 employees will remain. Staffing should remain stable until about 80 positions are cut in March, when demolition should be mostly completed.
The latest round of layoffs brings the total to 480 this year, including 180 employees who lost their jobs in February and 200 in June.
The metal parts furnace, which burned equipment and piping contaminated with chemical agents or caustics, remained in operation until mid-February, said URS spokesman Hal McCune. Debris is being sent to a landfill for contaminated material 40 miles west at Arlington, Ore.
About half the workers laid off in June transferred to jobs at similar plants where URS has contracts in Colorado and Kentucky. That layoff was associated with the shutdown of the facility's control room.
About a quarter of the workers to be laid off this week have jobs lined up at the Colorado and Kentucky plants, McCune said.
Few of the former incineration plant workers have found work at Hanford, where URS also holds contracts and subcontracts. In the early years of the incineration plant, job openings at Hanford were expected when work ramped down at the depot. But completion of work at the plant has coincided with layoffs at the nuclear reservation, and the start of operations at the Hanford vitrification plant has been delayed from 2011 to at least 2019.
Employees at the plant knew their jobs would not be permanent when they took them, McCune said.
Between 2004 and 2011, the plant incinerated more than 1 million pounds of chemical agents and more than 100,000 munitions, including bombs and projectiles that had been drained.
The contractor hired to demolish the building where the chemical weapons were processed and the associated pollution control systems is staging its equipment at the site now. Northwest Demolition of Tigard, Ore., plans to begin demolition Aug. 15.
A maintenance building and office and storage space will not be demolished and will be made available to Umatilla County government, port districts and private businesses.