2013-04-11_REVISION - C1981018 - Laserfiche WebLink

Home Browse Search

use /formulations. The majority of HAPs emitted from the Deserado Mine's operations are the result of the on -road and non -road vehicle use. The largest component of the HAPs emissions from these sources are typically various benzene compounds, and the majority of them are emitted from spark ignition (gasoline fueled) combustion sources. This is simply due to the fact that benzene is present in larger percent volumes in the fuel (typically 1.0 percent vs. 0.05 percent for diesel fuel). Green House Gases Gases that trap heat in the atmosphere are often called greenhouse gases, and include carbon dioxide (CO2), water vapor, methane (CH4), Nitrous Oxide (N20), and several fluorinated species of gases such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride (SF6). Carbon dioxide is emitted from the combustion of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, and also as a result of other chemical reactions (e.g., manufacture of cement). Methane is emitted during the production and transport of coal, natural gas, and oil. Methane also results from livestock and other agricultural practices and by the decay of organics in both the natural environment and from wastes in municipal landfills. Nitrous oxide is emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste. Fluorinated gases are powerful greenhouse gases that are emitted from a variety of industrial processes and are often used as substitutes for ozone - depleting substances (i.e., CFCs, HCFCs, and halons). These gases all have various capacities to trap heat in the atmosphere, which are known as global warming potentials (GWPs). Carbon dioxide has a GWP of 1, and so for the purposes of analysis a GHG's GWP is generally standardized to a carbon dioxide equivalent (CO2e), or the equivalent amount of CO2 mass the GHG would represent. As with the HAPs, ambient air quality standards do not exist for GHGs. In its Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act, the EPA determined that GHGs are air pollutants subject to regulation under the CAA. The most recent rules promulgated by EPA to regulate GHG emissions and the industries responsible are the Mandatory Reporting Rule (74 FR 56260) and the Tailoring Rule (70 FR 31514). Under the Mandatory Reporting Rule, Underground Coal Mines subject to the rule are required to report GHG emissions in accordance with the requirements of Subpart FF. Under the provisions of the Tailoring Rule (step 2 — July 2011) a facility would be subject to Title V & PSD permitting if it has the potential to emit GHGs in excess of 100,000 tpy of CO2e equivalent and 100/250 tpy of GHGs on a mass basis. Air Quality and Prevention of Significant Deterioration (PSD) Air quality for any given area (any geographical area that defines the class boundary) is designated as either attainment, or nonattainment. Attainment areas are those areas where criteria pollutant concentrations in ambient air do not exceed the NAAQS levels as outline above. Areas or regions where a criteria pollutant concentration in ambient air has exceeded the NAAQS are designated as nonattainment. Two additional subset categories of attainment exist for those areas where a formal designations have not been made, i.e. Attainment/Unclassifiable (generally rural, or natural areas), and for areas where previous violations of the NAAQS have been documented, but pollution concentrations no longer exceed NAAQS concentrations, i.e. DOI- BLM -CO- 110 - 2012 - 0023 -EA 18