Defense Environment Alert
an exclusive biweekly report on defense policies for cleanup, compliance and pollution prevention


Vol. 11, No. 22--November 4, 2003


OREGON DEQ PLANS NEW RISK ASSESSMENT FOR UMATILLA PLANT

Oregon regulators recently announced plans to conduct a new risk assessment to ensure operating conditions for the Army's Umatilla chemical weapons destruction facility are protective. Several reasons prompted the decision to develop a whole new risk assessment rather than add to a 1997 document, including the doubling of the facility's expected operation time, the regulators say.

The Oregon Department of Environmental Quality (DEQ) is taking public comment until Dec. I on its draft post-trial burn risk assessment workplan for the Umatilla Chemical Agent Disposal Facility, and will hold a public hearing on it Nov. 19, according to an Oct. 17 DEQ notice.

The final workplan will be used as a protocol for conducting a new risk assessment. The assessment will use a combination of data, including: data collected from the first trial burn at Umatilla using GB agent in the deactivation furnace; data from other operating facilities, preferably the Tooele, UT, plant; and metals emissions data from surrogate trial burns at Umatilla, a DEQ source says.

In contrast, the pre-trial burn risk assessment for Umatilla relied only on data from the Army's prototype facility on Johnston Island in the Pacific. Human health and ecological risk assessments estimate whether people or the environment will be harmed by air emissions released during normal, daily operations of a hazardous waste combustion facility like the Umatilla plant, DEQ says. Regulators rely on risk assessments to ensure the hazardous waste permit conditions for operating the plant are protective of human health and the environment, it says.

At Umatilla, the Army is continuing to conduct trial burns on surrogate agent. Operations with actual agent are expected to begin next summer, with a "shakedown" period followed by trial burns with agent, the DEQ source says. The Army plans to eventually incinerate a stockpile of 3,717 tons of nerve and blister agent munitions there. DEQ says it expects to finalize the risk assessment workplan by the end of February 2004. The new risk assessment will probably not be complete until the end of 2004, if not sometime in 2005, the DEQ source says.

A 1997 pre-trial burn risk assessment found that Umatilla disposal operations would not pose unacceptable risks to the community or environment, DEQ says. While the regulators originally planned to make addendums to this 1997 risk assessment by comparing actual trial burn data with initial estimates, they decided such additions would not sufficiently take into account numerous changes that have occurred since the original assessment, the notice says.

Since 1997, the Umatilla disposal plant "has collected six years of on-site weather data, [EPA] has published revised risk assessment guidance documents, air dispersion models have been improved, the [plant] has undergone numerous design modifications, and the facility is expected to operate more than twice as long as originally estimated," DEQ says in the notice.

A spokesman for the Chemical Weapons Working Group, a citizens' coalition that advocates non-incineration chemical weapons disposal methods, says the group will be closely following DEQ's risk assessment work. Such assessments will be a critical element to the plant's operational permit, the source says, noting the significance of DEQ's recognition that the existing risk assessment is no longer adequate to assess risks.