History of Chemical Stockpile Disposal Program (return to top)

For more than half a century, the United States has maintained a stockpile of chemical agents and munitions for possible use in wartime. The United States maintains its stockpile principally to deter other countries from using such weapons against U.S forces.

Since signing the Geneva Protocol condemning chemical weapons, the United States has sought to eliminate those in its own arsenal in a safe and environmentally responsible way. Up until the late 1960s, chemical agents and munitions were routinely disposed of using methods dating back to World War I, such as open-pit burning, land burial, or ocean dumping. The Army launched an extensive program that involves the development of new disposal concepts and process technology, new rigid worker safety and health standards and advanced monitoring equipment to document compliance with new health and safety standards and environmental regulations. Therefore, the Army established the Chemical Stockpile Disposal Project (CSDP).

The purpose of the Chemical Stockpile Disposal Project (CSDP) is to dispose of the stockpiled chemical agents and munitions, thereby eliminating the risk to the public from their continued deterioration and storage. After careful review of the options available for destroying the chemical stockpile, the Army decided that the safest way to dispose of the chemical weapons was by on-site incineration. This decision, which was supported by several independent studies, would eliminate the risk of transporting the stockpile to a centralized facility and confine the disposal process to the sites where the stockpiles are stored.

Additional information on the Army's chemical demilitarization program can be found at
http://www.cma.army.mil.

Following an extensive public comment period, the Environmental Quality Commission (EQC) and DEQ issued the permit (I.D. OR6 213 820 917) for the Storage and Treatment of Hazardous Waste (a hazardous waste permit) to the UMCD and the UMCDF on February 12, 1997. As a result of public comment, the EQC required that the UMCD and UMCDF establish a CMP. The purpose of the CMP is to confirm the projections of the pre-risk assessment. The CMP monitors for the presence of chemical warfare agents and other analytes to document that concentrations in soil, air, and biota before, during, and after UMCDF operations remain at or below the concentrations predicated in the pre-risk assessment.

The CMP is divided into three phases as shown in the Maps area of this site: baseline (before operations), operational, and post-operational monitoring. Baseline monitoring began in April, 1999 and concluded when agent operations began on September 7, 2004.  Operational monitoring began on that date and will continue until the end of thermal operations.  Post-operational monitoring will be conducted for one year following the conclusion of hazardous waste treatment operations at UMCDF. Sampling is conducted within three zones:

Selection of Samples (return to top)

The sample media collected at certain sample locations consist of air, soil and biota (vegetation and small mammals).  Air monitoring was initiated in May 2000 and will continue through the post-operational phase.  Air monitoring is conducted within the UMCDF boundary. The perimeter monitoring network (PMN) operated by the UMCDF collects air samples every 12 hours. These samples are analyzed for chemical agents by the UMCDF laboratory, and a data summary is included in the CMP quarterly report.

Surface Soil

Air

Air samples on the UMCD perimeter are conducted in Zone 1. This air sampling is termed the "perimeter monitoring network" (PMN). Air monitoring is not conducted in Zones 2 and 3 due to the dilution factors involved in sampling at locations beyond the UMCD boundary. Any agent concentration resulting from emissions at UMCDF would be lessened due to the long distance between the source and the sample location. Consequently, a large volume of air would have to be sampled over a long time period to result in a detectable amount of agent. Under these conditions, agricultural chemical application and automobile exhaust become the significant contributors to air composition.

Sampling Frequency (return to top)

The CMP consists of quarterly sampling events that encompass UMCDF construction, operations, and closure. Quarterly events in Zones 1 and 2 result in four measurements per year for soil and biota samples for all compounds monitored.  Soil sampling in Zone 3 will occur quarterly at three sites and semi-annually at four sites.  Sampling is conducted when a rigorous, long-term assessment of environmental conditions is needed.  Air monitoring is conducted to provide a historical record of agent concentrations in air at the perimeter of the UMCD.  Air samples are collected 365 days per year.

Selection of Compounds to be Monitored (return to top)

The CMP monitors for chemical agents (GB, VX, and HD) in the air at selected sites within Zone 1. Additionally, polychlorinated biphenyl, dioxin, furan, semivolatile and heavy metal concentrations in the soil and biological samples are measured.

These compounds enable a comparison of concentrations found during UMCDF operations to concentrations documented during baseline.  During trial burns (testing of the incinerator using surrogate material), the Army conducted extensive chemical analyses to evaluate the operating conditions of the incinerator.  Results of the trial burn phase were originally included in the operational phase data, but in February 2008, the DEQ approved the integration of the surrogate--testing phase with baseline data.  This decision was based on sporadic emissions over the two-year duration of trial burning that had little environmental impact.  See the section explaining other changes implemented with the approval of UMCDF-06-010-CMP(3).

Planning Documents (return to top)

The original planning document for the CMP was the Comprehensive Monitoring Program Workplan for the UMCDF and the Umatilla Chemical Depot, U.S. Army Project Manager for Chemical Stockpile Disposal, April 12, 1999.  This document can be requested from Ms. Virginia Harter at the phone number or e-mail address listed in the Contacts section. You may also mail in your request to Ms. Harter at the Washington Demilitarization Company address listed.

The CMP Sampling and Analysis Plan is included in the Permit (Attachment 5) and is the working document for the program.  This document may be requested from Ms. Harter, or by accessing Comprehensive Monitoring Program Sampling and Analysis Plan for the Umatilla Chemical Agent Disposal Facility and Umatilla Chemical Depot, Hermiston, Oregon, Washington Demilitarization Company, Rev 17, April 15, 2008.

CMP Interested Parties Workgroup (return to top)

The CMP Interested Parties Workgroup consisted of groups, agencies, contractors, or governments that expressed an interest in participating in the development of the CMP Work Plan. This group consisted of:

• Centers for Disease Control
• Citizens Advisory Commission, Hermiston, Oregon
• Confederated Tribes of the Umatilla Indian Reservation
• Ecology and Environment, Inc.
• Oregon Department of Agriculture
• Oregon Department of Environmental Quality
• Oregon Department of Fish and Wildlife
• Oregon Health Division
• Program Manager for Elimination of Chemical Weapons
• Washington Demilitarization Company
• Science and Applications International Corporation
• Tetra Tech EM, Inc.
• U.S. Department of Health and Human Services
• U.S. Environmental Protection Agency Region X
• U.S. Fish and Wildlife Service
• Umatilla Chemical Agent Disposal Facility
• Umatilla Chemical Depot
• Washington Department of Agriculture
• Washington Department of Health
• Washington Department of Ecology

Representatives of the Confederated Tribes of the Umatilla Indian Reservation, federal agencies, and state agencies from Washington and Oregon were invited to participate. In addition, community groups such as the Citizens Advisory Commission were contacted regarding the CMP. The Interested Parties convened in person and via telephone conference on February 12, 1998 with representatives of the DEQ facilitating the meeting.  A schedule for review of the August 1997 version of the draft Work Plan was presented, and various interested Parties expressed their views regarding the CMP.

Understanding Risk Assessment (return to top)

Risk assessment modeling estimates the likelihood that a chemical-related exposure (significant enough to cause adverse effects) may occur in a given human or animal population based on the estimated or measured concentrations of a given chemical in soil, air or animal tissue. Exposure can be modeled for any of three direct pathways by which a chemical enters into and interacts with an organism; typically expressed as doses (milligrams per kilogram of body mass per day).  These doses are compared to toxicity thresholds to determine the likelihood of an adverse effect or risk.

Methodologies for conducting ecological risk assessments are less defined, but are based on United States Environmental Protection Agency (USEPA) guidance documents (USEPA, Framework for Ecological Risk Assessment, Risk Assessment Forum, EPA Headquarters, EPA/630/R-92/001, February 1992). A conservative approach to risk modeling for animal receptors is to choose a species with the following characteristics:

• A species known to be present in the location of probable or measured highest contaminant concentrations for several environmental media for all or most of its lifecycle (that is, with a small home range relative to the area of potential contamination)
• A species of small body mass relative to the probable or expected contaminant concentration (i.e., to maximize potential dose)
• A species with behaviors that offer the highest potential for contact with contaminated media (i.e., species that spend a lot of time digging, plant eating species, species that eat both plants and animals or species that acquire food and water in the modeled potential contamination zone)