SBCT Final EIS - Govsupport.us

Chapter 5 – Environmental Consequencesheavy construction equipment would cause compaction of near surface soils that could result inincreased runoff and sedimentation. Clearing and grading during construction would expose the soilsto erosion. Dewatering may also be needed during construction, particularly for the utility trenches.However, engineering controls and BMPs including SWPP Plan would be used to minimize thesepotential impacts during construction.Construction and operation of new facilities would increase the use of fuels, solvents, and otherhazardous and toxic substances, which might result in indirect impacts to surface water if accidentallyreleased into the environment. FTC would implement BMPs and the SPCC to address leaks or spillsof hazardous materials. Potential spills would be typically small in magnitude and localized. Even alarge, uncontained spill, however, would have a low probability of affecting surface water, as thestreams at Fort Carson are intermittent. In addition, Fountain Creek is on the opposite side of a majorhighway (I-25), making it less likely for any spill to directly or indirectly affect this water body.Flood Potential. Floodplains in the southern part of the installation have not been delineated. Therecould be adverse impacts to flood-prone areas if construction of permanent facilities occurs withinflood-prone areas. Any construction activity within the 100-year floodplain in El Paso Countyrequires a Floodplain Development Permit issued by El Paso County. To avoid adverse impacts, newfacilities would be located to the extent practicable outside of known flood-prone areas includingareas immediately adjacent to arroyos. Floodwaters could also affect personnel and equipment,however, when training in flood-prone areas, especially during flash flooding. Safety of troops andequipment is a priority during training, and training procedures direct that troops relocate from floodproneareas when conditions are favorable for sudden storms and flash flooding.Measures described under Impacts from Cantonment Construction would also be followed for rangeconstruction. These measures will ensure impacts remain less than significant.5.4.3.3 Impacts from Live-Fire TrainingLess Than Significant ImpactsNonpoint source contamination of surface water. The munitions use increase could lead to increasedlocalized sediment loads and concentrations of ordnance constituents in impact area waterways.However, the munitions constituents would be identical to those currently in use. Studies have shownthat these constituents degrade rapidly over time and distance from point of impact, so environmentaleffects on groundwater would be limited (Houston 2002; Ferrick et al. 2001). Impacts are expected tobe less than significant.Increased training at FTC would increase the use of fuels, solvents, and other hazardous and toxicsubstances, which might result in indirect impacts to surface and/or ground water if accidentallyreleased into the environment. FTC would implement BMPs and SPCC to address leaks or spills ofhazardous materials. Impacts are expected to be less than significant.Flood potential. Personnel and equipment could be affected by floodwaters when training in floodproneareas, especially during flash floods. The safety of troops and equipment is a priority duringtraining, and training procedures direct that troops relocate away from flood-prone areas whenconditions are favorable for sudden storms and flash flooding.The following mitigation measures would be implemented to protect water resources from potentialimpacts resulting from live-fire training:February 2008 5-141 2/25th SBCT Final EIS