Hanford Site National Environmental Policy Act (NEPA) - Pacific ...

4.3.3 Clastic Dikes ........................................................................................................... 4.34
4.3.4 Structure and Tectonics........................................................................................... 4.35
4.3.5 Geology Specific to the Major Hanford Site Areas................................................. 4.37
4.3.5.1 Geology of the 100 Areas............................................................................ 4.37
4.3.5.2 Geology of the 200 Areas............................................................................ 4.38
4.3.5.3 Geology of the 300 Area ............................................................................. 4.39
4.3.6 Soils......................................................................................................................... 4.39
4.3.7 Seismicity................................................................................................................ 4.42
4.4 Hydrology................................................................................................................................ 4.49
4.4.1 Surface Water.......................................................................................................... 4.49
4.4.1.1 Columbia River ........................................................................................... 4.49
4.4.1.2 Water Quality of the Columbia River.......................................................... 4.52
4.4.1.3 Yakima River............................................................................................... 4.55
4.4.1.4 Springs and Streams .................................................................................... 4.55
4.4.1.5 Columbia Riverbank Springs....................................................................... 4.55
4.4.1.6 Runoff and Net Infiltration.......................................................................... 4.57
4.4.1.7 Flooding....................................................................................................... 4.58
4.4.1.8 Non-Riverine Surface Water ....................................................................... 4.64
4.4.2 Hanford Site Vadose Zone ...................................................................................... 4.66
4.4.2.1 Vadose Zone Contamination ....................................................................... 4.67
4.4.3 Hanford Site Groundwater ...................................................................................... 4.68
4.4.3.1 Basalt-Confined Aquifer System................................................................. 4.69
4.4.3.2 Unconfined Aquifer System ........................................................................ 4.69
4.4.3.3 Limitations of Hydrogeologic Information ................................................. 4.72
4.4.3.4 Groundwater Travel Times.......................................................................... 4.72
4.4.3.5 Groundwater East and North of the Columbia River .................................. 4.73
4.4.4 Groundwater Quality............................................................................................... 4.73
4.4.5 100 Areas Hydrology .............................................................................................. 4.75
4.4.6 200 Areas Hydrology .............................................................................................. 4.75
4.4.7 300 Area Hydrology................................................................................................ 4.81
4.4.8 North Richland Area Hydrology ............................................................................ 4.81
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