Washington - Department of Defense officials have reversed course and agreed to build a plant in Pueblo to destroy hundreds of thousands of mustard gas weapons stored there.

In a memo released Tuesday, Pentagon officials said they are dropping a study of the feasibility of moving the munitions to another state for destruction. They also said they will resume planning and budgeting for construction of the Pueblo facility.

Colorado's members of Congress, once irate at the prospect of losing hundreds of expected jobs and worried about the safety of moving the waste across the state, were elated.

"It's phenomenal. It's fabulous," said Sen. Wayne Allard, R-Colo. "Finally, common sense has prevailed."

Earlier this year, Pentagon officials concerned about rising costs and a lagging schedule put the brakes on long-standing plans to build the $2.5 billion facility.

They decided to study whether it would make more sense to haul the weapons to an existing plant for destruction, such as the Tooele Chemical Agent Disposal Facility in Utah.

Local leaders had spent years getting the military to agree to destroy the 780,000 mustard- gas shells with a water-based neutralization process instead of incineration. Residents were anticipating roughly 1,000 high- paying jobs.

Colorado lawmakers responded to the military's new reluctance with proposed legislation to ban the military from even studying shipment of the weapons and to order the military to start spending money on building the facility.

"There was a lot of political pressure against it," said Rep. John Salazar, D-Manassa. "A lot of members in neighboring states don't want it transported through their states."

The Pentagon memo from Defense Undersecretary Michael Wynne, released to members of Congress on Tuesday, says military officials have decided not to continue looking at transporting the arms "at this time."

Allard acknowledged that might allow "wiggle" room for Pentagon planners to look at transporting them in the future.

But he said the language in a spending bill expected to pass soon would not allow money to be spent even on studying planning without a change in the law.

Staff writer Mike Soraghan can be reached at 202-662-8730 or msoraghan@denverpost.com.