1、Addressing Air Quality Issues in the NEPA Process for Highway Projects 1AASHTO PRACTITIONERS HANDBOOKThe Practitioners Handbooks are produced by the Center for Environmental Excellence by AASHTO. The Centers Handbooks provide practical advice on a range of environmental issues that arise during the
2、planning, development, and operation of transportation projects. The Handbooks are primarily intended for use by project managers and others who are responsible for coordinating compliance with a wide range of regulatory requirements. With their needs in mind, each Handbook includes: key issues to c
3、onsider; a background briefing; practical tips for achieving compliance; and a list of reference materials.In addition, key regulations, guidance materials, and sample documents for each Handbook are posted on the Centers web site at http:/environment.transportation.org. American Association of Stat
4、e Highway and Transportation OfficialsCenter for Environmental Excellence by AASHTO18June 2017ADDRESSING AIR QUALITY ISSUES IN THE NEPA PROCESS FOR HIGHWAY PROJECTSThis handbook is intended to assist practitioners in addressing air quality issues, including transportation conformity requirements, as
5、 part of the National Environmental Policy Act (NEPA) process for highway projects. The handbook summarizes key requirements under NEPA and the Clean Air Act and provides advice for documenting compliance with the Clean Air Act requirements as a part of the NEPA process.The Background Briefing secti
6、on of the handbook provides an overview of requirements and relevant terminology.Topics addressed in the Practical Tips section of the handbook include: Determining if the project is subject to transportation conformity requirements Coordinating regional conformity determinations with the NEPA pro-c
7、ess Conducting hot-spot analyses and making project-level conformity determinations Considering mobile-source air toxics (MSAT) emissions Documenting air quality analyses and determinations in the NEPA processCopyright 2017, Center for Environmental Excellence by AASHTO (American Association of Stat
8、e Highway and Transportation Officials). All Rights Reserved. This book, or parts thereof, may not be reproduced in any form without written permission of the publisher. Printed in the United States of America.This material is based upon work supported by the Federal Highway Administration under Coo
9、perative Agreement No. DTFH61-07-H-00019. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the Author(s) and do not necessarily reflect the view of the Federal Highway Administration. 2017 by the Center for Environmental Excellence by AASHTO.All r
10、ights reserved. Duplication is a violation of applicable law.Addressing Air Quality Issues in the NEPA Process for Highway Projects 1This Handbook is intended to assist practitioners in addressing air quality issues, including transportation conformity requirements, as part of the National Environme
11、ntal Policy Act (NEPA) process for highway projects. The Handbook summarizes key requirements under NEPA and the Clean Air Act and provides advice for documenting compliance with the Clean Air Act requirements as a part of the NEPA process. The Background Briefing section of the Handbook provides an
12、 overview of requirements and relevant terminology. Topics addressed in the Practical Tips section of the Handbook include: Determining if the project is subject to transportation conformity requirements Coordinating regional conformity determinations with the NEPA process Conducting hot-spot analys
13、es and making project-level conformity determinations Considering mobile-source air toxics (MSAT) emissions Documenting air quality analyses and determinations in the NEPA processPlease note that this Handbook provides only a general introduction to transportation conformity requirements in relation
14、 to the analyses and decisions documented in the NEPA process; it is not a manual for carrying out air quality modeling or for making transportation conformity determinations. As such, this Handbook is likely to be most useful to practitioners who are experienced in NEPA but are not air quality spec
15、ialists. Background BriefingThis section provides an overview of key terms and concepts used in addressing air quality issues in the NEPA process for a highway project, including requirements for regional and project-level transportation conformity determinations under the Clean Air Act. Regional co
16、nformity requirements are addressed outside of the NEPA process as part of metropolitan planning, but they must be satisfied before the NEPA process is completed.NEPA RequirementsThe NEPA requirements applicable to an air quality analysis for a highway project are determined based on the Council on
17、Environmental Quality (CEQ) regulations and the environmental review regulations issued by FHWA (23 CFR Part 771). These requirements are further explained in several FHWA guidance documents, as described below. Many state departments of transportation also have issued guidance documents with advice
18、 on preparing air quality analyses in NEPA documents.CEQ Regulations. The CEQ regulations require consideration of the effects of a proposed action, including “ecological (such as the effects on natural resources and on the components, structures, and functioning of affected ecosystems), aesthetic,
19、historic, cultural, economic, social, or health, whether direct, indirect, or cumulative.”1Consistent with the CEQ regulations, FHWAs technical advisory on environmental documents requires consideration of air quality effects as part of NEPA compliance.2Comparative Analysis of Effects on Air Quality
20、. A comparative analysis of air quality impacts can be conducted as a part of compliance with NEPA. An EIS requires a comparative analysis of the environmental impacts of the alternatives, 1 40 CFR 1508.8.2 FHWA, Technical Advisory T6640.8A, “Guidance for Preparing and Processing Environmental and S
21、ection 4(f) Documents” (Oct. 30, 1987) (“Technical Advisory T6640.8A”).Overview 2017 by the Center for Environmental Excellence by AASHTO.All rights reserved. Duplication is a violation of applicable law.2 Addressing Air Quality Issues in the NEPA Process for Highway Projectsincluding where applicab
22、le the alternatives air quality impacts.3The requirements for an EA are more flexible both in terms of the number of alternatives considered and the level of detail in which impacts are analyzed. A categorical exclusion (CE) determination normally does not require an alternatives analysis.Considerat
23、ion of Air Quality Effects for Categorical Exclusions. Impacts on air quality should be considered when determining whether a project meets the criteria for a CE. The FHWA environmental regulations require a finding, as part of a CE determination, that the project will “not involve significant air,
24、noise, or water quality impacts.”4Documentation of Compliance with Other Requirements. The FHWA environmental regulations provide that a Final EIS or Finding of No Significant Impact (FONSI) “should document compliance with requirements of all applicable environmental laws and other requirements.”5A
25、ccordingly, compliance with NEPA includes not only a discussion of air quality effects, but also documentation of compliance with transportation conformity requirements under the Clean Air Act.6Normally, the conformity determination is documented in the Final EIS or FONSI. Where the conformity deter
26、mination cannot be made in the Final EIS, FHWA guidance requires it to be made by the time the Record of Decision (ROD) is issued.Consideration of MSAT Emissions. FHWA has issued and periodically updated interim guidance specifying the types of projects for which a NEPA document should include an an
27、alysis of MSAT emissions.7This interim guidance identifies three categories of projects: those with “no potential,” “low potential,” and “higher potential” to have meaningful MSAT emissions. A different level of MSAT analysis is recommended for each category of projects. (See below, “Mobile Source A
28、ir Toxics Analysis in NEPA Documents”).Consideration of Greenhouse Gas (GHG) Emissions. FHWA has not issued guidance addressing GHG emissions in NEPA reviews. As with other environmental impacts, EAs and EISs would address greenhouse gas emissions or climate change impacts depending on the significa
29、nce or the degree of controversy of the issue for the particular action. Current Practices. Air quality issues are normally considered as part of the environmental impacts analysis in a NEPA document for a highway project, but the particular approach to the air quality analysisthe level of detail an
30、d the topics addressedis determined on a case-by-case basis. Depending on the project, the following topics may be included in the air quality analysis in a NEPA document: Consideration of GHG emissions Documentation of compliance with conformity requirements, including hot-spot analysis where appli
31、cable Comparative emissions analysis for pollutants with national standards (known as “criteria pollutants”) Comparative analysis of MSAT emissions Discussion of construction emissions and mitigation Discussions of indirect and cumulative impacts on air quality Documentation of interagency coordinat
32、ion and public involvementTransportation ConformityThe Basics Section 176(c) of the Clean Air Act prohibits Federal agencies from funding or approving activities that do not “conform to” an applicable State Implementation Plan (SIP) for achieving compliance with the National Ambient Air Quality Stan
33、dards (NAAQS).8The rationale for this requirement is that the Federal governments actions should be consistent with states efforts to achieve and maintain compliance with Federally-established air quality standards. 3 40 CFR 1502.14. (An EIS “should present the environmental impacts of the proposal
34、and the alternatives in comparative form, thus sharply defining the issues and providing a clear basis for choice among options by the decision maker and the public.”)4 23 CFR 771.117(a) and 771.118(a).5 23 CFR 771.133. This regulation also states that “if full compliance is not possible by the time
35、 the Final EIS or FONSI is prepared, the Final EIS or FONSI should reflect consultation with the appropriate agencies and provide reasonable assurance that the requirements will be met. Approval of the environmental document constitutes adoption of any Administration findings and determinations that
36、 are contained therein.”6 FHWA, “Clarification of Transportation Conformity Requirements for FHWA/FTA Projects Requiring Environmental Impact Statements” (May 20, 2003).7 FHWA, “Updated Interim Guidance on Mobile Source Air Toxic Analysis in NEPA Documents” (Oct. 18, 2016) (“MSAT Guidance”).8 42 USC
37、 7506(c). 2017 by the Center for Environmental Excellence by AASHTO.All rights reserved. Duplication is a violation of applicable law.Addressing Air Quality Issues in the NEPA Process for Highway Projects 3A conformity determination typically involves analyses and findings made at both the regional
38、and project level. Conformity requirements must be met prior to completion of the NEPA process, so any delay in satisfying those requirements could delay completion of the NEPA process. In addition, a NEPA document normally summarizes the applicable conformity requirements and shows that those requi
39、rements have been met. Therefore, a basic understanding of regional and project-level conformity is essential to preparing adequate NEPA documentation. National Ambient Air Quality Standards (NAAQS). Established by the U.S. Environmental Protection Agency (EPA), the NAAQS specify the maximum allowab
40、le ambient concentrations for specific pollutants. To date, EPA has established NAAQS for six pollutants, commonly known as “criteria pollutants.”9Transportation sources contribute to four of the six criteria pollutants: Particulate matter (PM2.5 and PM10) Carbon monoxide (CO) Ozone Nitrogen dioxide
41、 (NO2)10There are multiple NAAQS for some pollutants. For example, for particulate matter, there are standards for PM10 (inhalable particles with diameters that are generally 10 micrometers and smaller) and for PM2.5 (fine inhalable particles with diameters that are generally 2.5 micrometers and sma
42、ller). Furthermore, PM2.5 has both an annual standard and a 24-hour standard.EPA is required to reassess each NAAQS for each pollutant periodically and update the standard if justified based on the latest scientific information regarding the effects of the pollutant on human health and welfare.11The
43、 process for updating a NAAQS typically takes several years and includes public notice and an opportunity for public comment. Nonattainment and Maintenance Areas. For each NAAQS, EPA designates specific geographic areasknown as “nonattainment areas”in which air quality conditions exceed the level sp
44、ecified by that NAAQS.12If a nonattainment area comes into compliance with a NAAQS, the state can request EPA to redesignate it as attainment. If redesignated as attainment, the area is required to develop a plan to maintain the standard for 20 years. Once redesignated, the area is then called a “ma
45、intenance area.”13As with the NAAQS themselves, EPA makes nonattainment and maintenance designations through a public notice-and-comment process. Designations of nonattainment and maintenance areas are made separately for each criteria pollutant and each NAAQS. Therefore, the same region may be in “
46、nonattainment” status for one pollutant, “maintenance” for another, and attainment (or unclassified) for others. In addition, there may be multiple NAAQS for the same pollutant, so the same region could be in nonattainment for one NAAQS and in attainment for another NAAQS for the same pollutant. Sta
47、te Implementation Plan (SIP). For each nonattainment area, the state must prepare a State Implementation Plan (SIP) that includes specific actions for achieving the applicable NAAQS.14States also are required to prepare SIPs for maintenance areas, demonstrating how the state will continue to maintai
48、n compliance with the NAAQS.15A separate SIP is prepared for each pollutant for which the area is in nonattainment or maintenance. As a result, a state may have multiple SIPs for the same geographic area, and at any given time, the SIPs may be in various stages of EPA approval process.16The state ai
49、r quality agency is responsible for preparing the SIP, and each SIP must be approved by EPA. For each pollutant, the SIP includes a motor vehicle emissions budget and may also include transportation control measures: Motor vehicle emissions budget. The SIP defines the total allowable level of emissions of a specific pollutant, and then allocates a portion of that total to emissions from highway and transit vehicles.17The allowable emissions level set for highway and transit vehicles is known as the motor vehicle emissions budget. 9 Current NAA
