2017-05-23_GENERAL DOCUMENTS - M1977472

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Table 3. Ambient Air Quality M nitoring Data Averaging County Pollutant units 2011 2012 2013 2014 '2015 Time Boulder 03 ppm 8-hour 0.076 0 076 0 079 0.070 0 074 Clear Creek 03 ppm 8-hour 0.080 0.084 0.085 0.075 0.073 Larimer 03 ppm 8-hour 0.077 0 079 0.074 0.069 0.075 Larimer CO ppm 1-hour 2.5 2.5 2.5 26 4.5 Larimer CO ppm 8-hour 1.3 1.7 1.4 1.4 14 Rio Blanco NO2 ppb 1-hour 5 5 4 4 4 Boulder PM25 µg/m3 24-hour 13 17 17 16 23 Boulder PM25 µg/m3 Annual 5.8 6.2 6 6.1 65 Larimer PM25 µg/m3 24-hour 15 26 18 20 24 Larimer PM29 µg/m3 Annual 57 1 7.3 6.8 6.5 6.1 Routt PM10 µg/m3 24-hour 79 93 77 81 68 µg/m3=micrograms per cubic meter. ppb=parts per billion. ppm=parts per million. Source.USEPA As shown in Table 3 above, the 4th highest 8-hour max ozone values for multiple years for nearby monitors are above the former and current 8-hour ozone Standard. Figure 3 (in Appendix A) shows that a small portion of the Denver/Front Range ozone Non-Attainment Area(NAA) extends into the far eastern side of the KFO. No other NAAs currently exist within the KFO. The proposed project will not be located within the ozone NAA. AQRVs are metrics for atmospheric phenomenon like visibility and deposition impacts that may adversely affect specific scenic, cultural, biological, physical, ecological, or recreational resources. Visibility changes can occur when excessive pollutant contaminates (mostly fine particles) scatter light such that the background scenery becomes hazy. Deposition can cause excess nutrient loading in native soils and acidification of the landscape, which can lead to declining buffering capacity changes in sensitive stream and lake water chemistries (commonly referred to as acid neutralization change (ANC)). Air pollutants are deposited by wet deposition (precipitation) and dry deposition (gravitational settling). The chemical components of wet deposition include sulfate (SO4), nitrate (NO3), and ammonium (NH4); the chemical components of dry deposition include sulfate, sulfur dioxide (S02), nitrogen oxides (NOx), nitrate, ammonium, and nitric acid (HNO3). A NPS memo suggests that the critical nitrogen load value for high elevation surface water in all natural areas of Colorado is 2.3 kg/ha-yr. The NPS Technical Guidance on Assessing Impacts on Air Quality in NEPA and Planning Documents suggests that critical sulfur load values above 3 kg/ha-yr may result in moderate impacts. AQRVs are important to FLMs because they have a mandate to ensure their Class I and sensitive Class II areas meet scientific (landscape nutrient loading) and congressionally mandated goals (i.e. regional haze). Class I areas are generally pristine landscapes such as national parks, national forests, and wilderness areas that are specifically provided the highest levels of air DOI-BLM-CO-N020-2017-0003 15