Last of Umatilla Chemical Depot's deadly nerve agent destroyed
By Annette Cary

HERMISTON -- No more nerve gas remains at the Umatilla Chemical Depot.

The last of the deadly agent was destroyed at 2:58 p.m. Wednesday after four years of work. Now the depot is ready to move on to its stockpile of less lethal mustard blister agent.

That doesn't mean those living near the depot can get rid of their supplies to shelter in place in the event of an emergency. But it makes it less likely that they ever will be needed.

"We thank the community for years of emergency preparedness effort and support," Lt. Col. Bob Stein, depot commander, said in a statement Wednesday.

Not only has all the nerve agent been incinerated at the Umatilla Chemical Agent Disposal Facility, but also all the agent with explosive components because it was in bombs, land mines, rockets or artillery projectiles.

The mustard blister agent that remains is in one-ton containers used for shipping and storage rather than contained in munitions. There are not a lot of the containers -- 2,635 out of a total of 220,604 stored at the depot until incineration began. But the mustard agent makes up more than half the stockpile by weight.

The Umatilla Chemical Agent Disposal Facility will need five months to change over equipment and procedures for incinerating the mustard blister agent and its metal containers.

Then incineration is expected to take one or two years, depending on whether problems are encountered. In one new twist, workers will be dealing with "heels" of solid or semi-solid agent that have collected in the bottom of some containers.

In addition, a lawsuit was filed Friday by Hermiston-based GASP, the Oregon Wildlife Federation, Sierra Club and others to stop the incineration because of concerns about whether mercury in the agent would be fully captured by filter systems.

The mustard blister agent is not only less dangerous because it is not in explosive weapons, but it also would be difficult for a plume of it to travel off the post, said Bruce Henrickson, depot spokesman. Because mustard agent vapor is more than five times heavier than air, spreading it off the post would require unusual conditions such as a fire combined with specific wind conditions, he said.

However, precautions developed by the Chemical Stockpile Emergency Preparedness Program will remain in place because the risk will remain until the last of the agent is destroyed, Henrickson said.

The mustard blister agent, while toxic, is less lethal than the sarin and VX agent already destroyed. A drop of those nerve agents could kill within minutes.

The mustard blister agent takes up to 24 hours to work by causing chemical burns or blisters to tissue it touches, including in the eyes and lungs. It also can cause cancer. It was designed to prohibit the movement of enemy soldiers during battle.

The mustard blister agent at the depot dates from World War II and is in the form of an oily liquid. While vapors of sarin and VX could not be smelled, particularly in a pure form, the mustard blister agent has an odor similar to garlic or horseradish.

"We'll remain fully committed to safety as we prepare to dispose of the mustard ton containers, said Mike Strong, the Army's site project manager at the disposal facility, in a statement after the last of the nerve agent was destroyed.

"The Army said we'd do it. We did it. And we did it safely," he said.

Original at: http://www.tri-cityherald.com/kennewick_pasco_richland/story/374985.html