|Selection of a Sampling Methodology|
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 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 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 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.
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.