SBCT Final EIS - Govsupport.us

Chapter 4 − Impact Methodologyordnance use, engine emissions from military vehicle use, fugitive dust from vehicle travel onunpaved roads, wind erosion from areas disturbed by off-road vehicle maneuvers, and engineemissions from personal vehicle use associated with added personnel.Factors that determine the level of air quality effects include the increase of air pollutant emissionsgenerated from SBCT activity relative to the baselines established in the Hawaii, Alaska andColorado and the status of local air quality and nearby sensitive areas.In general, the methodology used to assess air quality impacts includes use of USEPA emissions data,methodologies, emission rate models, and air dispersion models to predict emission rates and tocalculate ambient air quality impacts. Results of emission rate calculations and model predictionswere compared to the national and state regulations and standards.In Hawaii, emissions of windblown fugitive dust from areas disturbed by off-road vehicle maneuverswere estimated using a proprietary wind erosion rate model and wind speed data from on-postmeteorological stations. A modeling analysis of fugitive dust issues was also conducted to determinethe potential degree of impact and the geographic extent of the impact. In Alaska, USEPA emissionsdata were used to calculate emissions from stationary sources, such as heating systems andgenerators. Impacts on visibility were also assessed targeting the Denali National Park Class I Area.In Colorado, emissions from stationary sources and impacts on visibility were also evaluated.4.12.2 Resource-specific significance criteriaMajor factors considered in determining whether a project alternative would have a significant impacton air quality include the following:• Whether or not the analyses indicated a potential for violation of federal and state standards forcriteria pollutants at off-post locations;• Whether or not relatively high emissions would occur on a continuing basis for periods longerthan the time frame of relevant ambient air quality standards (e.g., 8- hour periods for ozoneprecursors, 3-hour and 24-hour periods for sulfur oxides, 24-hour periods for PM 10 );• Whether or not emissions of precursors to ozone or other secondary pollutants would occur insuch quantities and at such locations as to have a reasonable potential to cause or contribute to aviolation of federal or state ambient air quality standards; or• Whether or not emissions of hazardous air pollutants could exceed state standards or otherhazardous air pollutant exposure guidelines at locations accessible to the general public.4.13 NOISE4.13.1 Resource-specific Impact Analysis MethodologyUnder the Army’s ENMP (formerly known as the Installation Compatible Use Zone Program) theArmy evaluates the impact of noise that may be produced by ongoing and proposed Army actions andactivities. The ENMP characterizes noise into three primary zones (Noise Zones 1-3). Noise Zone(NZ) 1 is typically suitable for all types of land uses and is located the furthest from the noise source.NZ II and NZ III are generally considered incompatible for noise-sensitive land uses.February 2008 4–17 2/25th SBCT Final EIS