Geology and ground-water characteristics of the Hanford Reservation of the U.S. Atomic Energy Commission, Washington

Hanford Site National Environmental Policy Act (NEPA) characterization. Revision 7

“…Where these coarse-grained units are overlain by an unnamed mud unit, the gravelly sediments are designated Unit B in the eastern part of the basin, or Unit D in the western part. In the 200 West Area and vicinity, there is only one thick sequence of fluvial gravel and sand, part of which may include 4.24 Tallman et al 1979 Alluvium (Bjornstad 1985;Brown 1960;Newcomb et al 1972). Following incision, a welldeveloped soil formed on top of the eroded surface.…”

“…Because the Ringold sediments are more consolidated and partially cemented, they are about 10 to 100 times less permeable than the sediments of the overlying Hanford formation. Before wastewater disposal operations at the Hanford Site, the uppermost aquifer was mainly within the Ringold Formation and the water table extended into the Hanford formation at only a few locations (Newcomb et al 1972 …”

“…Late Miocene to Pliocene deposits, younger than the Columbia River Basalt Group, are represented by the Ringold Formation within the F'asco Basin (Groiier and Bingham 1978;Gustafson 1973;Newcomb et al 1972;Rigby and Othberg 1979 Fluvial deposits of the Ringold Formation can be broken into three facies associations based on proximity to the ancestral Columbia and/or Snake River channels and the related paleography during the time the Ringold Formation was being deposited. Gravel and associated sand and silt represent a migrating channel deposit of the major, thorough going river systems and are generally confined to the central portion of the Pasco Basin.…”

Hanford Site 1997 Environmental Report

“…This aquifer and other confined aquifers are generally isolated from the unconfined aquifer by dense rock that forms the interior of the basalt flows. However, interflow between the unconfined aquifer and the basaltconfined aquifer system is known to occur at faults that bring a water bearing interbed in contact with other sediments or where the overlying basalt has been eroded to reveal an interbed (Newcomb et al 1972, RHO-RE-ST-12 P, WHC-MR-0391). Additional information on the basalt-confined aquifer systemcan be found in PNL-10158 and PNL-10817.…”

Hanford low-level tank waste interim performance assessment

“…The strata of the Ringold Formation are generally divided as follows (Newcomb 1958;Newcomb 1972;Bjornstad 1984;DOE 198813):…”