SBCT Final EIS - Govsupport.us

Chapter 5 – Environmental ConsequencesThe Army often conducts prescribed burns, which are meant to reduce fuel loading (build up of easilyignitable vegetation) that can lead to large-scale wildfires, but which can also create bare areassusceptible to erosion. Those potential erosion impacts were discussed and approved for the NEPAprocess undergone for the IWFMPs for Pohakuloa and Oahu Training areas, described below. Soilerosion resulting from fires ignited by weapons training related activities is considered to be apotentially significant impact at all applicable Hawaii installations. Implementation of the mitigationmeasures mandated by the IWFMPs, described below, would reduce these impacts to less thansignificant.Regulatory and Administrative Mitigation 2: The IWFMP for Pohakuloa and Oahu Training Areaswas finalized in June 2006. The Army would fully implement the IWFMP for all existing and newtraining areas to reduce the impacts associated with wildland fires. The plan considers the potentialneed for firebreaks and/or fuel breaks at each installation along with other safety concerns.The IWFMP would be updated to address proposed activities along the Kawaihae Harbor-PTA trail.These updates would be completed before activities commence. Additionally, ITAM geographicinformation systems would be used to monitor the effectiveness of wildfire management activities.Army personnel would practice BMPs in operations, and trained personnel and equipment would beon hand during training activities to respond to wildfires. IWFMP wildfire managementinfrastructure, such as the three dip tanks proposed for PTA, would be constructed before SBCTtraining commenced. During training, appropriate personnel and equipment would be assigned towater resources for responding to a wildfire.Less than Significant ImpactsExposure to Soil Contaminants during Live-Fire Training Activities. Low levels of explosive residuesare associated with munitions use. Studies have shown that TNT residue is readily metabolized bysoil microbes and the byproducts bind to organic matter. Areas with higher organic matter contentappear to bind residues more rapidly. The explosive residues RDX and HMX do not degrade rapidlyand are not very soluble; however, once dissolved in water, both can be highly mobile in soil.Munitions are fired from firing points downrange and into the range impact areas. The Army restrictsaccess to these areas by Soldiers or members of the public because of the explosive risk to safety theyrepresent. It is unlikely; therefore, that military personnel or off-post residents would come intocontact with the constituents of these munitions in the downrange impact area soils. The risk tomilitary personnel who use the ranges would be low because contact with downrange impacted soilsis unlikely and there are relatively few areas with high chemical constituent concentrations. Therewould be no risk to the general public from munitions constituents related to range use because therewould be no public access to these areas. Exposure to soil contaminants during live-fire trainingactivities is considered a less than significant impact.Volcanic and Seismic Hazards: As described previously, portions of the areas that would be used forlive-fire training under Alternative A are subject to volcanic eruptions, lava flows, occasionalexplosive eruptions, volcanic gas venting, and earthquakes. Weapons firing at the SBMP and PTABAX ranges and the MOUT range on KTA is not expected to have any effect on the frequency ofvolcanic eruptions or earthquakes; therefore, the impact would be the hazards to personnel associatedwith weapons training in areas in which volcanic and seismic hazards exist. Alternative A mayincrease the hazard to personnel associated with volcanic and seismic hazards because it wouldinvolve personnel training on the two new BAX ranges at SBMP and PTA and additional personneltraining on the MOUT range at KTA, which could increase the potential for Soldiers to be injured bydamaged structure features, heavy military vehicles, falling rock, or lava. On Oahu, the expectedFebruary 2008 5-9 2/25th SBCT Final EIS