Chapter 3. Affected Environment Lower Sonoran/SDNM Draft RMP/EIS 253 3.1. INTRODUCTION This chapter describes the environment within the Lower Sonoran Planning Area that would potentially be affected by actions proposed under the alternatives described in Chapter 2, Alternatives (p. 27). While the Bureau of Land Management (BLM) is only responsible for managing BLM-administered public lands (public lands) within the Planning Area (i.e. the Lower Sonoran and Sonoran Desert National Monument [SDNM] Decision Areas), proposed decisions may affect environmental components outside the Decision Areas. Therefore, unless indicated otherwise, discussion and analysis in this section encompasses the Planning Area as a whole. The environmental components potentially impacted consist of resource and management activities listed below. The foreseeable environmental effects of the alternatives on these same resource and management activities are described in Chapter 4, Environmental Consequences (p. 371). Resources Resource Uses Air Quality Lands and Realty Cave Resources Livestock Grazing Management Climate Change Minerals Management Cultural and Heritage Resources Recreation Management Geology Travel Management Paleontological Resources Special Area Designations Priority Wildlife Species and Habitat Management National Landscape Conservation System Soil Resources Administrative Designations Vegetation Resources Other Special Designations Visual Resources Social and Economic Water Resources Tribal Interests Wild Horse & Burro Management Hazardous Materials and Public Safety Wilderness Characteristics Social and Economic Conditions Wildland Fire Management The data and descriptions of these categories are drawn from the Analysis of the Management Situation (AMS) (BLM 2005) and subsequent, completed resource assessments on several of the environmental components occurring within the Planning Area. The AMS is available for public review at the BLM’s Phoenix District Office. Chapter 3 Affected Environment August 2011 Introduction 254 Lower Sonoran/SDNM Draft RMP/EIS 3.2. RESOURCES 3.2.1. AIR QUALITY 3.2.1.1. Clean Air Act Land Classifications The BLM’s role in air-resource management is to ensure that agency activities comply with applicable air-quality standards and that BLM-authorized leases and permits include conditions and stipulations that require compliance with applicable air quality rules and standards. This is done through interagency coordination, participation in State implementation plans, environmental impact analyses as required by NEPA, and adaptive management practices as outlined in BLM Handbook H-1601-1. Under the Federal Clean Air Act (CAA), national parks 6,000 acres or larger and wilderness areas 5,000 acres or larger existing in 1977 were designated as Class I. The class 1 designation gives Federal land managers the opportunity to impose the strictest rules protecting air quality. The Planning Area includes one wilderness area with a Class I air quality designation, Superstition Wilderness, located east of Phoenix. Undeveloped, remote areas deserving of natural or scenic resource preservation could be designated as Class II. Other wilderness areas and national parks, including those designated after 1977, are classified as Class II, and land managers are limited to less strict protection of air quality. State and local air quality planning and permitting agencies give such places special consideration under the CAA through Prevention of Significant Deterioration criteria even though they do not qualify as Class I. Within the Planning Area, nine wilderness areas have been designated Class II for air quality. These include three areas containing designated wilderness outside the Decision Areas (Organ Pipe Cactus National Monument, Cabeza Prieta National Wildlife Refuge (NWR), and Four Peaks wildernesses), three within the Lower Sonoran (Woolsey Peak, Signal Mountain, and Sierra Estrella wildernesses), and three within the SDNM (Table Top, North Maricopa Mountains, and South Maricopa Mountains wildernesses). The CAA requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for pollutants harmful to public health or the environment. It also establishes two types of national standards: primary standards to protect health and secondary standards to protect welfare. The EPA sets NAAQS for six principal or “criteria” pollutants. The pollutants are carbon monoxide (CO), lead, nitrogen dioxide (NO2), one-hour ozone (O3), sulfur dioxide (SO2), and particulate matter smaller than 10 micrometers in effective diameter (PM10). Geographic areas are designated as attainment, nonattainment, or unclassified for each of the criteria pollutants with respect to NAAQS. An area is designated as “attainment” if pollutant concentrations meet the NAAQS, “nonattainment” if pollutant concentrations exceed the NAAQS, or “unclassified” if the status of attainment has not been verified through data collection. For planning and permitting purposes, unclassified areas are treated as attainment areas. All counties making up portions of the Planning Areas, with the exception of Yuma County, contain some areas that are designated as nonattainment with respect to specific criteria pollutants that include PM10, SO2, CO, and O3 (Arizona Department of Environmental Quality [ADEQ] 2006). The air-pollution nonattainment areas are shown in Map 3-1: Air Pollutant Nonattainment Areas. Chapter 3 Affected Environment Resources August 2011 Lower Sonoran/SDNM Draft RMP/EIS 255 3.2.1.2. Emission Sources Diverse emission sources within the Planning Area collectively affect air quality on a local and regional scale, including major, minor, non-permitted, mobile, and fugitive emission sources. For permitting purposes, a major source is defined as an emission that has the potential to emit100 tons or more per year of any single criteria pollutant, 10 tons per year of any single hazardous air pollutant, or 25 tons per year of any combined hazardous air pollutants. Major sources include industrial facilities such as gas-fired power plants, natural gas pipeline compressor stations, landfills, mineral processing facilities, and various manufacturing plants with largefuel combustion equipment or use substantial quantities of volatile organic materials, typically in application of finishes and coatings. A minor source is defined as an emission that has the potential to emit pollutants at a levelgreater than the “significance” threshold, but less than a major source. The significance threshold provides an emission baseline for criteria pollutants that determines which facilities must obtain permits. Minor sources include industrial and commercial facilities of many kinds, especially in the more developed portions of the Planning Area. Although minor emission sources vary outside the metropolitan Phoenix area, common sources are rock-product plants that produce crushed and screened materials, and hot-mix asphalt and concrete plants. These plants can be found in the Lower Sonoran and are often portable, which means that they can be moved as the local demand for their product moves. The primary emissions from these sources are particulate matter; however, nitrogen dioxide (NO2) can also be significant if any equipment operates using fuel-fired generators. Many small, stationary emission sources, such as agricultural operations and large-scale construction projects, do not produce air pollution levels that would substantially affect regional air quality, and are not required to have an operating permit. Such sources may occur in the Decision Areas on occasion. However, emissions from these facilities, mostly in the form of particulates, can affect local air quality due to the arid soil conditions. While non-permitted sources are not tracked as closely as permitted sources, these must also comply with applicable Federal, State, and local regulations. Vehicle travel on paved roads, especially in the metropolitan Phoenix area, represents the largest single emission source in and surrounding the Planning Area. When CO from vehicle emissions combines with the extreme desert heat, O3 is created. Other major contributors in the Planning Area include traffic on interstates and other major thoroughfares, including Interstates 10,17, and 8 (I-10, I-17, and I-8); U.S. Highways 60 and 89 (U.S. 60 and U.S. 89); and State Highway 87 (SR 87). In a similar fashion, railroad corridors can be significant emissions contributors in the Planning Area’s central portions. Particulate matter carried onto paved roadways from wind and rain events and soil tracked onto highways by vehicles entering from unpaved roads are common sources of PM10 pollution. Most vehicle routes in the Decision Areas are unpaved. Travel on unpaved routes results in particulate emissions, or fugitive dust. Although fugitive dust is not included in air quality evaluations, it can affect local air quality, especially in areas of concentrated travel on unpaved roads and during periods of high winds. The largest source of particulate matter emissions in the Planning Area is surface-disturbing activities, including construction, mining, and off-highway (recreation-related) travel, all of which occur in the Decision Areas. State and local nonpoint-source rules guide these activities. Chapter 3 Affected Environment August 2011 Air Quality 256 Lower Sonoran/SDNM Draft RMP/EIS Maricopa County recommends best management practices (BMPs) such as applying water or chemical dust suppressants to