The activists' criticism came as they and the Army await a federal report expected this month on DuPont Co.'s proposal to treat and dispose of the waste at its Deepwater, N.J., plant.
During news conferences in Indianapolis and New Jersey, they predicted political pressure will eventually doom the Army's plans to enlist DuPont to dispose of the caustic wastewater created by the destruction of the Cold War-era VX nerve agent stored at western Indiana's Newport Chemical Depot.
"Clearly the Army's waste transportation proposal is going down the drain," said Elizabeth Crowe of the Berea, Ky.-based watchdog Chemical Weapons Working Group.
An Army contractor began last May destroying more than 250,000 gallons of VX - a liquid so deadly even a tiny droplet can kill a human - in special chemical reactors at the complex about 30 miles north of Terre Haute.
That project is expected to produce about 4 million gallons of hydrolysate, a chemical the Army wants to truck hundreds of miles to DuPont's Deepwater plant, where it would be treated and discharged into the Delaware River.
That plan has generated strong opposition in both New Jersey and Delaware from critics who fear traces of VX and other toxic byproducts would reach the river even after treatment.
Activists in Indiana, Ohio, Pennsylvania and Kentucky also oppose the disposal plans, warning of environmental damage if a truck carrying hydrolysate overturned.
The U.S. Centers for Disease Control and Prevention is reviewing DuPont's proposal and other issues, including the risks of trucking the hydrolysate from Indiana to New Jersey.
CDC spokeswoman Stephanie Creel said the agency expected to release its report to Congress on the matter sometime this month.
Sara Morgan, a retired schoolteacher who lives three miles from Newport's stockpile, said during Thursday's news conference at the Indiana Statehouse that residents near the depot have urged the Army for years to treat the VX waste at the depot.
"We ask them to do what's right and keep it on site," she said.
The activists want the Army to destroy Newport's hydrolysate using the original method proposed for the job - a treatment process called supercritical water oxidation.
That high-pressure treatment would yield a solid that would then be buried in a landfill.
Crowe said the military has exaggerated technical problems involving that process, which the Army dropped in mid-2001 in favor of offsite shipment of the hydrolysate.
She said it makes sense to deal with chemical waste onsite, rather than shipping it hundreds of miles.
"Our nation's waste problems will not be solved by one community dumping on another, but rather by the safest, most efficient treatment of waste possible - as close to the source as possible," Crowe said.
Jeff Lindblad, a spokesman for the Army's Chemical Materials Agency at Aberdeen Proving Grounds, said Thursday the military estimates that pursuing the high-pressure treatment at Newport would add another two years and hundreds of millions of dollars to the project.
Building two high-pressure reactors at Newport alone would cost about $35 million, he said. Newport's hydrolysate is also so corrosive it would require replacing the reactors' lining hundreds of times, adding to the cost and time of the project.
To date, an Army contractor has destroyed about 15 percent of the VX stored at Newport, where about 198,300 gallons of hydrolysate is now stored. The complex has current storage capacity for about 617,000 gallons of hydrolysate, depot spokeswoman Terry Arthur said.