SBCT Final EIS - Govsupport.us

Chapter 5 – Environmental ConsequencesIBCT Training, the impacts of compaction, rutting, and damage to permafrost from Stryker vehiclemaneuver activities would not be substantially greater. Due to the large size of DTA and isolateddistribution of permafrost and soils susceptible to compaction, rutting and damage to permafrost onFRA and DTA, overall the impacts are expected to be less than significant with implementation ofmitigation.Regulatory and Administrative Mitigation 5: Implementation of standard BMPs, as well asrevegetation and other land restoration projects implemented by the LRAM, TRI, and SRA programsof the USARAK INRMP and ITAM annual work plan (described previously) would reduce theseimpacts to less than significant.Additional Mitigation 5: The following additional mitigation measures would also help reduce theimpact.• Conduct permafrost mapping, sensitivity analysis, and model development.• Study the effects of fire on active layer thickness and permafrost degradation on maneuver lands.• Conduct real-time analysis of ground conditions to support maneuver land use.• Prevent off-road vehicle traffic in high permafrost areas during summer months when the groundis thawed.Impact 6: Increased Potential for Slope Failure. Impacts associated with increased potential for slopefailure resulting from road use are expected to be similar to those discussed for the Alternative A.Areas of steep slopes and erosive soils on FRA and on DTA are located on steep slopes and erosivesoils are located in the foothill areas of the Donnelly Drop Zone and North Texas Range.Regulatory and Administrative Mitigation 6: Implementation of standard road maintenance BMPsmitigation measures described in the LRAM, TRI, and SRA programs of the USARAK INRMP andITAM annual work plan would reduce these impacts to less than significant.Less Than Significant ImpactsVolcanic and Seismic Hazards. Similar to cantonment and range construction, maneuver training isnot expected to have any effect on the frequency of volcanic eruptions or earthquakes; therefore, theimpact would be the hazards associated with the training occurring on ranges in areas in whichvolcanic and seismic hazards exist. The potential for strong ground motion at DTA is similar to FRAbecause the Denali Fault runs through the training area; however, the potential for damage resultingfrom earthquakes on DTA would be lower than at FRA, because of the significantly smaller numberof structures and less human activity on DTA. The impacts associated with seismic and volcanichazards during maneuver training would be less than significant because existing warning systems aregenerally expected to provide the possibility of warning of an earthquake or eruption such thatpersonnel and equipment would likely have time to evacuate.5.3.3 Water ResourcesPotential impacts to water resources resulting from Alternative B include impacts on stream channelmorphology, surface water quality, and groundwater quality and supply. At FRA, impacts to surfacewater quality due to increased erosion and sedimentation related to training activities and constructionof new facilities may result. Other impacts include impacts on water quality from spills and leaks,increased munitions use, and increased water use from added troops. At DTA, impacts to streamchannel morphology and water quality due to increased erosion and sedimentation related to trainingFebruary 2008 5-79 2/25th SBCT Final EIS