Geohydrologic characterization of the area surrounding the 183-H Solar Evaporation Basins

Abstract

, the Pacific Northwest Laboratory has been conducting a geohydrologic in<estigation of the area surrounding the 183-H Solar Evaporation Basins (183-H Basins), located on the Hanford Site in southeastern Washington State. The purpose of this investigation is to achieve regulatory compliance with the applicable groundwater monitoring requirements of • the Resource Conservation and Recovery Act (RCRA} and the Washington Administrative Code (WAC). An assessment-level compliance monitoring project was established for the 183-H Basins because hazardous waste constituents were known to have entered the ground water beneath the facility. Three phases were defined for this project with work being concentrated in five areas: geology, hydrology, ground~water monitoring~ geochemistry, and groundwater modeling. These characterization activities have resulted in the definition of principal lithologic and hydrostratigraphic units. Groundwater monitoring results indicated a contamination peak, which occurred between April and August 1986. Further monitoring has shown that nitrate, sodium, gross alpha, and gross beta are the clearest indicators of groundwater contamination attributable to the 183-H Basins. In addition, the concentrations of these contaminants are affected by variations in Columbia River stage. Future studies will focus on continued groundwater monitoring throughout the clo• sure and post-closure periods for the 183-H Basins, sampling of the Columbia River and nearby groundwater springs, and soil sampling adjacent to the facility .

RCRA (Resource Conservation and Recovery Act of 1976) ground-water monitoring projects for Hanford facilities: Progress report, October 1--December 31, 1988: Volume 1, Text

“…1987a,b,c,d;1988b,c,d;Fruland, Bates, and Lundgren 1989) contain information on the progress made and the data obtained by the Resource Conservation and Recovery Act (RCRA) GroundWater Quality Assessment Program for the 183-H Solar Evaporation Basins during the period May I, 1986through September 30, 1988. In addition, a final hydrogeologic characterization report has been published (Liikala et al 1988). A Final Status Post-Closure Permit Application for this facility was submitted to the Washington State Department of Ecology in June 1988 (WHC !988a).…”

“…Well locations are shown in Figure 3.1. A water-table map is included in Liikala et al (1988) and will be included in the next quarterly report.…”

Resource conservation and recovery act ground-water monitoring projects for Hanford facilities: Progress report, January 1--March 31, 1989

“…The 183-H Solar Evaporation Basins consist of four concrete basins in the 100-H Area (see Figures 1.1 and 3.1) that were used for solar evaporation and storage of aqueous chemical wastes from nuclear fuel processing operations elsewhere on the Hanford Site (Liikala et al 1988). The wastes discharged to the basins consisted primarily of nitric, sulfuric, and hyd(ofluoric acids, contaminated by heavy metals and radionuclides, and neutralized by sodium hydroxide.…”

“…Gross alpha, gross beta, and technetium-99 exceed the 900-pCi/L standard in EPA (1976). Liikala et al (1988) have shown that the apparent shape and extent of the contaminant plume extending from the 183-H basins is highly dependent upon river stage. At high river stage (see Figure 3.5), there is a temporary gradient reversal, although the net annual flow is towards the Columbia River.…”

Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

“…Hydraulic property data used in the development of the prior model were obtained from the results of hydraulic tests documented in Bierschenk (1959), Kipp and Mud (1973), Deju (1974), Lindberg and Bond (1979), Graham et al (1981), DOE (1988a), Liikala and Aaberg (1988), Thorne and Newcomer (1992), Peterson (1992), Connelly et al (1992aConnelly et al ( , 1992b, Swanson (1992), Thorne et al (1993), Connelly (1994), and Swanson (1994). Information was also obtained from new tests and tests that were previously undocumented.…”