HERMISTON -- The incineration plant at the Umatilla Chemical Depot has destroyed 90 percent of the mustard chemical weapon agent stored at the depot.

Wednesday, the 2,371st ton container of mustard agent was destroyed in the Umatilla Chemical Agent Disposal Facility to hit the 90 percent disposal mark for the agent.

The mustard agent is the last of the chemical munitions remaining at the site. Depot officials expect the final mustard agent to be destroyed in November, a little more than seven years after the first chemical munition was destroyed Sept. 8, 2004.