Nevada Test 1999 Waste Management Monitoring Report, Area 3 and Area 5 radioactive waste management sites

Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS). These monitoring data include radiation exposure, air, groundwater, meteorology, vadose zone, and biota data. Although some of these media (radiation exposure, air, and groundwater) are reported in detail in other Bechtel Nevada reports (Annual Site Environmental Report [ASER], the National Emissions Standard for Hazardous Air Pollutants [NESHAP] report, and the Annual Groundwater Monitoring Report), they are also summarized in this report to provide an overall evaluation of RWMS performance and environmental compliance. Direct radiation monitoring data indicate that exposure at and around the RWMSs is not above background levels. Air monitoring data indicate that tritium concentrations are slightly above background levels, whereas radon concentrations are not above background levels. Groundwater monitoring data indicate that the groundwater in the alluvial aquifer beneath the Area 5 RWMS has not been affected by the facility. Meteorology data indicate that 1999 was a dry year: rainfall totaled 3.9 inches at the Area 3 RWMS (61 percent of average) and 3.8 inches at the Area 5 RWMS (75 percent of average). Vadose zone monitoring data indicate that 1999 rainfall infiltrated less than one foot before being returned to the atmosphere by evaporation. Soil-gas tritium data indicate very slow migration, and tritium concentrations in biota were insignificant. All 1999 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing as expected at isolating buried waste.