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Umatilla Chemical Depot


“To protect people and the environment by overseeing the safe destruction of chemical agents at the Umatilla Chemical Depot as soon as possible.”

Program overview

The Oregon Department of Environmental Quality’s Chemical Demilitarization Program, based in Hermiston, Oregon, provides environmental and human health oversight of the Umatilla Chemical Agent Disposal Facility, eight miles west of Hermiston. The facility, administered by the U.S. Army Chemical Materials Agency, is operated under contract by Washington Demilitarization Company LLC. The facility is in charge of destroying by incineration the stockpile of chemical munitions that had been stored at the Army’s nearby Umatilla Chemical Depot for decades. 

DEQ's provides its oversight through its issuance and updating of a hazardous waste storage and treatment facility permit for the disposal facility. The official permittees for the facility are the Umatilla Chemical Depot and Washington Demilitarization Company. DEQ's role includes conducting periodic inspections of the facility and analyzing operational reports that the facility must submit to the state to ensure environmental compliance. DEQ is responsible for making sure the facility strictly follows permit conditions such as proper hazardous waste storage, maintenance and monitoring, as well as proper equipment maintenance, to ensure the facility operates in a manner that won't harm the public or environment.


In October 2011, the Army completed destruction of the last chemical munitions materials that had been stored at the Umatilla Chemical Depot. The Umatilla Chemical Agent Disposal Facility destroyed nearly 4,000 tons of chemical agent since it began incinerating the material in September 2004. 

As of Oct. 25, 2011 the Umatilla Chemical Agent Disposal Facility had completed safe destruction of all of the following chemical agents: 

  • GB rockets, containing deadly sarin nerve agent. Destruction completed July 8, 2007.
  • Sarin nerve agent VX munitions. Destruction completed Nov. 5, 2008.
  • HD ton containers (“mustard" or blister agent). Destruction completed Oct. 25, 2011.

The Umatilla Chemical Agent Disposal Facility is one of eight facilities in the United States and one in Johnston Atoll in the Pacific Ocean in charge of destroying the stockpile of chemical munitions that the Army has accumulated over the decades. It is the sixth to complete its work. So far, facilities in Newport, Indiana; Pine Bluff, Arkansas; Anniston, Alabama; Johnston Atoll; and Aberdeen, Maryland, have completed their destruction of chemical agents. Facilities in Tooele, Utah; Blue Grass, Kentucky; and Pueblo, Colorado continue efforts to safely destroy their local stockpiles of chemical weapons. Complete destruction of chemical agent stockpiles in the United States is now expected by 2023.​

​Storage of hazardous wastes at UMCD has been conducted in accordance with regulations implementing the Resource Conservation and Recovery Act of 1976 (RCRA) at both the federal and state levels. In 1984 a Hazardous Waste Storage Permit was issued jointly by the U.S. Environmental Protection Agency (EPA) and the DEQ to UMCD. The conditions of the 1984 Storage Permit defined how UMCD would manage hazardous wastes generated by operational activities not involving chemical weapons.

The storage of chemical munitions that have been declared waste (waste CMs), and the agent-contaminated wastes that result from maintenance of the chemical weapons, are regulated separately under the RCRA "Interim Status" provisions of 40 CFR 265 and other applicable RCRA regulations, as adopted in Oregon Administrative Rules(OARs). In March 2001 changes in the OARS called for the chemical weapons and bulk items in the UMCD inventory to be classified as hazardous wastes. The storage units have been upgraded to the meet the new requirements and an increased monitoring schedule has been implemented. DEQ inspects the UMCD every quarter, and conducts a joint inspection with the Environmental Protection Agency (EPA) at least once a year. DEQ will issue a Notice of Non-Compliance if there are any environmental violations noted during an inspection.

The 1984 Storage Permit issued to UMCD has since expired, but it will continue to apply until a new Permit is issued. A RCRA "Part B" Storage Permit Application, to update conditions applicable to hazardous waste storage operations at UMCD, was submitted by the U.S. Army and has been determined by DEQ to be substantially complete. The Permit Application review process involved resolution of storage issues with the Army, development of draft Permit language, formal comment period(s) and public meeting(s) to receive input from members of the general public and other interested parties. The RCRA Part B Storage Permit addresses conventional and agent-related wastes and governs all aspects of hazardous waste storage operations at UMCD.

The UMCDF Resource Conservation and Recovery Act (RCRA) Hazardous Waste Storage and Treatment Permit was issued in 1997. Hazardous waste activities allowed by the Permit include treatment by incineration; storage and treatment in tanks; and treatment by separation of munition components. Conditions in this Permit include requirements for waste analysis, air monitoring, training, security, emergency response, pollution prevention, design, construction, and operational parameters. The DEQ conducts weekly inspections of the UMCDF and issues a Notice of Non-Compliance if the inspectors note any environmental violations. The DEQ has a written history of enforcement actions(1987-2000) and (2001 - 2003).

The UMCDF Hazardous Waste Storage and Treatment Permit is considered an operating document, and many modifications of the document are expected to occur over the duration of the project. Modifications are required if there are alterations to the originally permitted facility, new information becomes available to the Permittee or to DEQ, or there are new regulations that apply to the facility. All Permit Modification Requests (PMR) are tracked through a DEQ database and are available in PMR report form.

RCRA Hazardous Waste Treatment and Storage Permit

Each module is updated with Permit Modifications on a quarterly basis as needed. The Module revision date is located in the upper right hand corner of each page.

The following documents are modified excerpts from the permittee’s RCRA Part B Permit Application. The listed documents are hereby incorporated, and made part of this Permit. The Department has modified specific language in the Attachments. These incorporated Attachments are enforceable Conditions of this Permit, as may be modified by the specific Permit Conditions. Specific Permit Conditions (Module I through IX), supersede the language of the Attachments if the Permit Condition and Attachment language are found to be in conflict.

While destruction of chemical agents in Oregon has concluded, DEQ's Chemical Demilitarization Program will continue overseeing the Umatilla Chemical Depot/Washington Demilitarization Company hazardous waste storage and treatment facility permit as the facility is closed down. 

The permit, which was most recently renewed Sept. 20, 2011 and expires Sept. 20, 2021, includes a formal facility closure plan. The facility must follow detailed procedures to properly dismantle and dispose of equipment used in the incineration of chemical agent. The Umatilla Chemical Depot/Washington Demilitarization Company's is currently seeking a permit modification to allow disposal of secondary waste from the weapons destruction operations to be shipped to an authorized hazardous waste landfill.​

The Umatilla Chemical Depot began receiving and storing chemicals munitions between 1962 and 1969. The chemical warfare agents VX and GB (nerve agents) and HD (blister or “mustard" agent) were stored as liquid in various types of munitions and containers, including rockets, bombs, projectiles, mines, bulk containers and aerial spray tanks. Chemical weapons stored at the Depot represented about 12 percent of the nation's original chemical weapons stockpile. 

In 1985 Congress directed the Army to destroy the entire U.S. chemical agent stockpile, as directed by the international Chemical Weapons Convention treaty. The treaty originally required signatory countries to completely destroy all chemical agent stockpiles by the year 2007. Since that time, countries have been given an extension to 2012. Congress has mandated that destruction of all chemical agent stockpiles in the U.S. be complete by Dec. 31, 2017. The U.S. Department of Defense is working with Congress to accelerate the program to come as close to meeting the 2017 deadline as possible. 

In February 1997, the Oregon Environmental Quality Commission, DEQ's governing body, issued environmental permits to the Army to construct, operate and ultimately close down the Umatilla Chemical Agent Disposal Facility. Prior to the commission's approval of those permits, DEQ in 1996 conducted a Pre-Trial Burn Human Health and Ecological Risk Assessment. In 2010, DEQ completed a Final Post-Trial Burn Human Health and Ecological Risk Assessment, using site-specific emission data from the facility. The assessment showed that the facility's incineration of the chemical agent was being handled safely and effectively.​


Oregon DEQ
Chemical Demilitarization Program 
400 E. Scenic Dr., Suite 307
The Dalles, OR  97058
Phone:  541-298-7255

TTY:  503-229-6993