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

The U.S. Army applied for a Hazardous Waste Permit in March 1995. Prior to issuance of the Hazardous Waste Permit, the Oregon Department of Environmental Quality (DEQ) conducted a pre-trial burn risk assessment (pre-RA). The pre-RA indicated the UMCDF would not have a significant adverse effect on human health or the environment (Ecology and Environment, Inc., 1997).

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: 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:

• Zone 1 encompasses the area within the Depot boundary
• Zone 2 covers the area within 31 miles of the Depot
• Zone 3 extends beyond 31 miles from the facility

Primary activities for the CMP include:

• Field sampling of soil and biota
• Laboratory analyses
• Data validation
• Statistical analyses
• Report preparation
• Posting of data on Internet.

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

Surface soil sampling is conducted in all three zones. Soil samples are collected at each of 21 separate locations within the three zones on a quarterly basis and at an additional four sites in Zone 3 during the April and October events. The soil sampling stations are maintained and sampled to provide quarterly trending information. Three locations on the Depot have long-term soil stations with a larger collection area. Soil from these long-term boxes is collected in a previously unsampled area biennially to measure cumulative deposition.

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.

Biota

Biota sampling is conducted at selected sites in all three zones. Predominant species of plants and small animals have been identified for biota sampling. Specifics are outlined in the Sampling and Analysis Plan. Biota samples are only collected at those locations where they are available. Due to weather conditions or other environmental factors, biota may not always be available at the identified locations.

Sampling Frequency

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

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).

Compounds measured as part of the CMP were selected because they contributed the highest percentages to potential health risk as identified in the pre-RA.

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 Mr. Randal Fox at the phone number or e-mail address listed in the Contacts section. You may also mail in your request to Mr. Fox 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 Mr. Fox, 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.

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 10
• 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

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)

These characteristics favor the selection of a species that would be expected to receive the maximum environmental dosage. If the results of the ecological risk assessment indicate a potential for toxic effects, it may be appropriate to conduct other assessments. However, if modeling reveals no significant risk to these types of species, toxic effects would not be expected in other species with larger ranges, larger body masses, diets that include sources outside the modeled potential deposition zone or dining habits that keep them aboveground most of the time.

Permit modification request (PMR) UMCDF-06-010-CMP(3) proposed changes to the Comprehensive Monitoring Program (CMP) Sampling and Analysis Plan (SAP). The CMP SAP is Attachment 5 of the Hazardous Waste Permit under which the Umatilla Chemical Agent Disposal Facility (UMCDF) operates. The designation of a Class 3 PMR means it received the highest level of public involvement. It was subject to two public comment periods during the process. The following changes were approved by the Oregon Department of Environmental Quality (DEQ) on February 4, 2008.

• The DEQ approved elimination of terrestrial invertebrate sampling. Prior to this change, terrestrial invertebrates were collected three out of four scheduled events (January events were excluded).


• Collection of surface water was also eliminated. Results of water sampling showed few detected results (three percent detects for organics, four percent for inorganics) and statistical trending was not possible. Sources for water samples were flowing waters of the Umatilla River, water from the Columbia River used as a wetland water source, and one spring-fed pond.


• Sampling frequency was changed to semiannually at four of six sites in Zone 3 near Pendleton, Oregon. Sites 3‑1, 3‑3, 3‑4, and 3‑6 will be sampled in April and October, and Sites 3‑2 and 3‑5 will be sampled every quarter. Site 3‑7 in Washington will also keep the quarterly sampling schedule.


• The number of agent analyses in soil was reduced. Sites 1‑3, 1‑4 and 1‑10 will continue to be analyzed for chemical agent.


• Several changes were approved that affect baseline threshold data. Baseline threshold values will be recalculated using an upper tolerance limit (UTL) rather than the upper confidence level (UCL). This brings the process in line with EPA guidance documents, and is more appropriate for the intent of CMP comparisons. Two years of surrogate testing will be included in the baseline threshold recalculations. In addition, reporting limits will now be added to the screening process when operational data are compared to baseline.


• A different strategy has been approved for presenting trending information. Recurring values above baseline (5 or more) will be listed in a table in each quarterly report, but only those with significant upward trends will be graphed in the quarterly report. Annual reports will show all recurring values (5 or more) in a graph, regardless of significant upward trend estimates.


• DEQ approved biennial sampling at the long-term soil sampling stations. The first biennial event will be in October 2009.

Changes will be implemented prior to the April 2008 sampling event. Historical data will still be maintained for those media where collection has ended. An updated Baseline Threshold Report will be posted to this website when it is completed.