Qualitative PM_(2.5)/PM_(10) Conformity Determination: A Case Study Analysis

摘要

On March 10, 2006, the Environmental Protection Agency (EPA) issued amendments tothe Transportation Conformity Rule to address localized impacts of particulate matter,entitled PM_(2.5) and PM_(10) Hot-Spot Analyses in Project-level Transportation ConformityDeterminations for the New PM_(2.5) and Existing PM_(10) National Ambient Air QualityStandards (71 FR 12468). These amendments require the assessment of localized airquality impacts of federally-funded or approved transportation projects that are deemedto be projects of air quality concern that are located in PM_(2.5) or PM_(10) nonattainment andmaintenance areas.Also in March of 2006, the EPA and the Federal Highway Administration (FHWA)issued Transportation Conformity Guidance for Qualitative Hot-spot Analyses in PM_(2.5)and PM_(10) Nonattainment and Maintenance Areas. This document providesmethodologies for conducting the qualitative hot-spot analyses that are required for thesetypes of projects until EPA releases its future quantitative modeling guidance andannounces that quantitative PM_(2.5) and PM_(10) hot-spot analyses are required under 40CFR93.123(b)(4).PB has recently completed a number of PM_(2.5) and PM_(10) conformity compliancedemonstrations for transportation projects located across the country in accordance withthe EPA/FHWA Guidance. A number of issues have come up that will be presented inthis paper as case studies. These issues include the selection of a representative ambientair quality monitor, traffic data (or lack thereof) near this monitor, the year of peakemissions, the required discussion of the "Built and Natural Environment" of theproposed project area, the qualitative estimate of future PM_(2.5)/PM_(10) levels, and the lackof a "No Build vs. Build" comparison. These issues will be discussed along with thevalidity of the overall results.