The Pine Bluff Arsenal is set to resume disposal of chemical weapons four months after maintenance work put the project on hold, officials said this week.

Workers began moving munitions from the underground storage igloos earlier this week to the Chemical Agent Disposal Facility to prepare for disposal to resume.

"We do expect to transport munitions all this week; at any point during that time, we could start processing the items," said Randy Long, the Chemical Agent Disposal Facility site project manager. Processing could begin as early as the end of the week but will more likely resume early next week, he said.

Processing was halted Jan. 10 to replace plastic pipes in the facility's pollution-abatement system with pipes made from an alloy. The pipes carry a cleaning solution used in the system that cools and cleans exhaust gases from the incinerators. Similar work has been done at the Umatilla, Ore., facility and the facility in Anniston, Ala.

Long said the old pipes required a lot of maintenance and the new ones should require less.

Since incineration began with the draining of two rockets filled with the nerve agent GB on March 29, 2005, the facility has destroyed 34,207 GB rockets, about 38 percent of its stock, and 352,782 pounds of the GB nerve agent, about 5 percent of its stock.

The arsenal, citing security reasons, won't disclose the amount of chemical agents it stores in underground igloos, but at the start of the project, the arsenal stored 12 percent of the Army’s chemical weapons stockpile. So far, 16 underground igloos have been emptied.

Last month Secretary of Defense Donald Rumsfeld said he expects just two-thirds of the nation’s chemical weapons stockpile to be disposed of by a 2012 deadline. New schedules indicate that sites in Alabama, Oregon, Colorado and Kentucky will all miss the deadline. A Maryland site has completed the disposal, and sites in Utah and Indiana are on schedule.

Long said, however, that the Pine Bluff Arsenal could still meet the 2012 deadline.

Greg Mahall, a spokesman for the U.S. Army Chemical Materials Agency at Aberdeen Proving Ground, Md., said that the Army is still trying to determine when all the sites will finish disposing of their stockpiles.

"We’re constantly involved in a process to, sadly, predict the future. That’s hard to do," Mahall said. Unanticipated delays in obtaining environmental permits, work stoppages and complications that have arisen from handling the aging munitions have all put the country behind schedule.

"It's a continually evolving process," Mahall said. "The key has always been and always will be safety."

As of May 3 the United States had destroyed 10,125 metric tons, or 36.5 percent, of its chemical weapons stockpile, according to a news release from the U.S. Army Chemical Materials Agency.

Under terms of the international Chemical Weapons Convention treaty, the United States had 10 years from April 29, 1997, when the treaty became effective, to destroy its stockpile of 27,768 metric tons of chemical agents. The treaty included a provision for a five-year extension, which the United States has requested.

The Pine Bluff Arsenal opened in 1941 to manufacture mustard blistering agents and lewisite, another blistering agent, and to assemble munitions. Production of chemical weapons there ended in 1969. Since the 1970s, the arsenal has produced nonlethal chemical agents, tested chemical defense equipment and manufactured munitions using such chemicals as white phosphorus.

This story was published Wednesday, May 10, 2006