Human and Ecological Risk Assessment - Earthjustice

Appendix CAttachment C-2: Hydrogeologic EnvironmentHydrogeologic SettingHydrogeologic Environment (continued)Hydrogeologic EnvironmentPlant Code Description Code DescriptionEckert Station 7Eb River Alluvium Without 7 River Valleys and FloodplainsOverbank Depositswithout Overbank DepositsEdgewater 7Bc Outwash Over SolutionLimestonePercentageComment70 Percentage based on productive aquifercoverage, Heath regions12 Solution Limestone 100 Setting based on aquifer and surficialgeology coveragesElmer W Stout 7D Buried Valley 4 Sand and Gravel 100 Glaciofluvial aquifer overlaid by alluvialdepositsF B Culley 6Fa River Alluvium WithOverbank DepositsFayette PowerPrj10AbUnconsolidated and Semi-Consolidated ShallowSurficial AquiferFlint Creek 6Db Alternating Sandstone,Limestone and Shale - DeepRegolithFort Martin 6Fa River Alluvium WithOverbank Deposits6 River Valleys and Floodplainswith Overbank Deposit10 Unconsolidated andSemiconsolidated ShallowAquifers100 Predominant alluvial setting; soils havesignificant fines (SCL+SLT = 94%)100 Setting based on aquifer and surficialgeology coverages2 Bedded Sedimentary Rock 100 Ozark plateau; Heath (1985) indicatesdolomite, sandy dolomite, sandstone, with noindication of solutioning. Surficial geology(cherty red clay) noted as thick regolith inAller et al. (1987)6 River Valleys and Floodplainswith Overbank Deposit100 Setting based on surficial geology; low SNL(< 1%) = overbank depositsFrank E Ratts 7D Buried Valley 4 Sand and Gravel 100 Glaciofluvial aquifer in alluvial valley region(99%)G G Allen 8D Regolith 1 Metamorphic and Igneous 100 Based on surficial geologyGadsden 6Db Alternating Sandstone,Limestone and Shale - DeepRegolithGadsden 6Fa River Alluvium WithOverbank DepositsGallatin 6Fa River Alluvium WithOverbank Deposits2 Bedded Sedimentary Rock 30 Percentage assigned based on productiveaquifer coverage6 River Valleys and Floodplainswith Overbank Deposit6 River Valleys and Floodplainswith Overbank Deposit70 Percentage assigned based on productiveaquifer coverage; soils have significant fines(SCL+SLT > 25%)100 Setting based on surface geology; high (56%)SCL = overbank deposits(continued)April 2010–Draft EPA document.C-2-7