Two months from now, the U.S. Army hopes to start incinerating rockets filled with sarin nerve agent now stored at Umatilla Chemical Depot near Hermiston.

The step is overdue. The Army once promised to have destroyed the site's entire 3,700-ton inventory of chemical weapons by 2003. But lawsuits, construction delays, environmental rules and other problems intervened.

It's still not clear when the first sarin weapon will enter the incinerator. Umatilla leaders say it will be mid-July. But "there's an awful lot of work that has to be done by the Army and by the contractor," Washington Demilitarization Co., to meet of state environmental requirements and be allowed to start burning weapons, said Dennis Murphey, the Department of Environmental Quality administrator overseeing the effort.

This week, Oregonians get their chance to discuss whether the incinerator is ready to start destroying some of the country's deadliest arms, as the Oregon Environmental Quality Commission meets in Hermiston. Commissioners are scheduled to tour the incinerator plant today and meet with representatives of local, state, national and tribal governments.

The commission will take public comments from 7 to 9 p.m. Thursday at the Hermiston Community Center. The agency is taking written comments on the question until June 7.

At least some of those comments will say that the incinerator is not ready to start now and question whether it ever should. Some watchdog groups in Oregon and nationwide say that the incinerator's technology isn't proved or safe enough, and say the Army has a spotty record of managing other, similar chemical weapons incinerators in the United States.

"I don't think it's wise at all to start" in July, said Karyn Jones, a member of the Hermiston activist group Gasp, which has sued to stop the incinerator. "They still have so many things to take care of."

For example, Jones said, the facility must decide what to do with waste created by the incinerator's operation, such as wood pallets and worker-protection suits. Plans originally called for a "dunnage incinerator" that would treat such incidental waste. The Army abandoned that plan, but military officials and state regulators have not approved a new way to dispose of such items.

Jones noted that Gasp and other plaintiffs are still asking Multnomah County Judge Michael Marcus to modify or revoke the Army's permit to run the incinerator. The plaintiffs want the state to require a method of chemical-weapons destruction besides incineration, such as chemical treatments. Final briefs in that case are due July 14, Jones said.

"Depending on what Judge Marcus rules, they may be forced to switch technologies," she said.

Under the Army's ideal schedule, workers would finish testing all the incinerator's systems and addressing environmental worries in the next month or so. Then DEQ officials could advise members of the Environmental Quality Commission to allow incineration to start at the commission's July 16 meeting.

"We could start up immediately after that," if the commission approves, Army spokeswoman Mary Binder said.

Binder acknowledged that technical and regulatory work is needed to get permission to start the incinerator. She said that work would not be sacrificed to a deadline.

"It's just a lot of moving parts," Binder said. "As our plant manager said, 'The hardest part of the process is just getting the plant online.' "

The plant includes four separate furnaces. Two of them will be used to destroy the rockets containing sarin, which the Army says are the depot's most dangerous weapons and the first slated for destruction. The remaining furnaces will help destroy other weapons at the depot, which also stores the nerve agent VX and mustard gas, a blister agent.

It's not clear how much work remains before Umatilla can put a real weapon into its first two incinerators. A handful of different studies have created competing lists of jobs for workers, some of which are being finished every day.

The DEQ may keep the most important list, a "Compliance Assessment" finished in May that listed 69 steps the Army must finish to be allowed to start up. Murphey said the Army has fulfilled 39 of those requirements, and he expects "many" of the 30 remaining items to be completed by the end of May.

Several of the items are complicated and labor intensive, posing the biggest challenges to starting the incinerator soon. Those include finishing the testing of a brine reduction system, which will treat some waste created by the incineration process. The Army must also address concerns raised by tests on the two furnaces it needs to start destroying sarin rockets.

The DEQ must decide whether to grant some changes the Army is seeking to permits. That includes a request to move the site for taking measurements of chemicals in the incinerator's smokestacks. Now, the permit calls for measuring before exhaust gases hit a series of carbon filters. The Army wants to measure after the filters do their work, which should lower levels of contaminants.

Binder and Washington Demilitarization spokesman Rick Kelley said they face self-imposed hurdles to starting the incinerators, as well.

The contractor did its own "operational readiness review" last year and prioritized more than 1,500 tasks, the most important of which must be completed before treating weapons. Most of those vital items are complete, Kelley said, estimating that fewer than 60 remain. The company is addressing other questions that arose during an operations demonstration watched by officials from the Army, DEQ, the national Centers for Disease Control and Prevention and other agencies.

Once the company decides it's ready to burn weapons, Army officials at the depot will then review the contractor's work, Binder said. If they agree the incinerator is ready, they will tell Congress and the DEQ. The final two approvals probably will come from the Army's top chemical-weapons officials and Oregon environmental regulators.

Kelley and Binder emphasized that the public would get notice before the first weapon is destroyed.

"We're going to start in as a slow process. We may do one, or maybe two, rockets that day, and then we're going to evaluate the data," Kelley said. "It'll be a long process and a deliberate process."

Andy Dworkin: 503-221-8239; andydworkin@news.oregonian.com