By ANNETTE CARY

Attorneys for the Government Accountability Project have filed a lawsuit to stop a plan by Oregon agencies to incinerate the Umatilla Chemical Depot’s cache of World War II mustard agent.

The suit was filed in the Multonomah County, Ore., state circuit court by the watchdog group’s attorneys on behalf of Hermiston-based GASP, the Oregon Wildlife Federation, Sierra Club and six Umatilla County and Morrow County residents.

The lawsuit attempts to stop the incineration by seeking a judge’s review of recent decisions made by the Oregon Environmental Quality Commission and Department of Environmental Quality to move forward with plans for incinerating mustard agent and the secondary waste.

The Government Accountability Project, or GAP, is concerned that some of the mustard agent is contaminated with mercury and other hazardous wastes. It believes the mercury would not be fully captured by the filter systems currently in place or planned for the Umatilla Chemical Agent Disposal Facility.

Department of Environmental Quality officials could not be reached Monday afternoon about the lawsuit, but the commission has given approval for using enhanced carbon filters for incineration of mustard gas after the department studied options.

Late this week the depot could hit an important milestone, with the last of its nerve agent destroyed. That will leave only the HD mustard blister agent in ton containers to be destroyed.

Changes of equipment at the disposal facility will take about five months and then incineration of the mustard agent could take one to two years.

More than 60 percent of the chemical agent stockpile at the depot is mustard agent, according to GAP. However, the Army has identified containers contaminated with mercury and they comprise 16 percent of the total.

“The agencies have not even required the Army to test the contents of the mustard ton containers, so they have no real facts to back up their assumptions about this part of the stockpile,” said Karyn Jones of Hermiston, in a statement.

The plan to dispose of the mercury-contaminated mustard ton containers “is not safe or protective of the environment,” said GAP attorney Richard Condit, in a statement.

The lawsuit filed Friday follows a lawsuit filed a year ago seeking a moratorium on burning secondary wastes and mustard agent at Umatilla.