NYT: The end of the United States chemical weapons arsenal

...“We had to figure it out as we went,” said Walton Levi, a chemical engineer at the Pueblo depot, who started working in the field after college in 1987 and now plans to retire once the last round is destroyed.

At Pueblo, each shell is pierced by a robot arm, and the mustard agent inside is sucked out. The shell is washed and baked to destroy any remaining traces. The mustard agent is diluted in hot water, then broken down by bacteria in a process not unlike the one used in sewage treatment plants.

It yields a residue that is mostly ordinary table salt, Mr. Levi said, but is laced with heavy metals that require handling as hazardous waste.

“Bacteria are amazing,” Mr. Levi said as he watched shells being destroyed during the last day of operations at Pueblo. “Find the right ones, and they’ll eat just about anything.”

The process is similar at the Blue Grass depot. Liquid nerve agents drained from those warheads are mixed with water and caustic soda and then heated and stirred. The resultant liquid, called hydrolysate, is trucked to a facility outside Port Arthur, Tex., where it is incinerated....

Pretty cool stuff, take a look!