SBCT Final EIS - Govsupport.us

Chapter 5 – Environmental ConsequencesAlthough this EIS supplements the 2004 EIS and considers all the projects in the original document,the special focus of this document is on those projects required by the SBCT. It is these projects thatwould not occur if the SBCT were to be stationed elsewhere; essentially, it is these projects that arethe key variables as the Army considers where to station the 2/25th SBCT permanently. Therefore,the analysis in section 5.2 focuses most closely on these SBCT projects.5.2.2 Geology, Soils, and SeismicityTable 5-3 lists the significance of soil erosion and other geologic, soils, and seismic-related impactsthat would occur under Alternative A for each type of project activity. Because the SBCT is currentlylocated at SBMR, no new cantonment construction would be necessary.Table 5-3Summary of Potential Soil Erosion Impacts from Alternative ALocationActivity Group SBMR DMR KTA/KLOA PTAImpacts from Cantonment Construction N/A N/A N/A N/AImpacts from Range Construction N/A Impacts from Live-Fire Training N/A Impacts from Maneuver Training = Significant + = Beneficial Impact = Significant but mitigable to less than significant N/A = Not Applicable☼ = Less than Significant= No ImpactConstruction of the BAX ranges at SBMR and PTA, and the range maintenance facility adjacent toPTA are expected to cause direct, short-term, localized soil erosion impacts when ground surfaces aredisturbed to construct live-fire villages, trench lines, stationary armor targets, machine gun bunkers,and other typical BAX features. Because construction would occur in previously disturbed areas, thisimpact is considered significant but mitigable to less than significant with implementation of standardconstruction BMPs.Construction of Dillingham Trail is expected to lead to potentially significant short-term increasedsurface disturbance, soil erosion and compaction, and potential for slope failure in steep areas, but theimpacts could be reduced to less than significant with implementation of standard road constructionBMPs. After construction, however, the roads could affect surface drainage in the long-term, both byfocusing drainage collected from impermeable surfaces onto adjacent lands and by interfering withnatural drainage patterns. These impacts could be reduced with mitigation, but not to less thansignificant levels.New and existing ranges would be operated under Alternative A, some of which would support livefiretraining. Munitions impact and wildfire sparked by fired weapons can remove vegetative coverand disturb soils, resulting in larger areas of bare ground than observed under current conditions,leading to increased rates of erosion in weapons training ranges. This impact is considered significantbut mitigable to less than significant with implementation of revegetation projects implemented underthe ITAM annual work plan (described below) and wildfire management practices implemented byUSAG-HI.February 2008 5-5 2/25th SBCT Final EIS