State and Local Transportation Resources
Project-Level Conformity and Hot-Spot Analyses
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This page contains policy guidance, technical guidance, and other resources issued by EPA to assist agencies in completing project-level conformity analyses, including particulate matter (PM2.5 and PM10) and carbon monoxide (CO) “hot-spot” analyses.
- PM Hot-spot Analyses: Guidance
- CO Hot-spot Analyses: Guidance
- Emission Models and Methods
- Air Quality (Dispersion) Models
- Tools for Completing Project-level Analyses
- Training and Other Resources
- Frequently Asked Questions
- Contact Information
PM Hot-spot Analyses: Guidance
- Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas
EPA has released final guidance for modeling the local air quality impacts of certain transportation projects on the PM2.5 and PM10 national ambient air quality standards (NAAQS). This guidance is to be used by state and local agencies to conduct quantitative PM “hot-spot analyses” for new highway and transit projects that involve significant diesel emissions. This guidance describes how to estimate project emissions using EPA’s MOVES model, California’s EMFAC model, and other methods. It also outlines how to apply air quality models (such as AERMOD and CAL3QHCR) for PM hot-spot analyses. The guidance also includes a list of additional resources that may assist agencies in conducting quantitative PM hot-spot analyses. Update of November 2013: This guidance was originally released in December 2010, and Sections 5, 7.6, and 9.4 have been updated to reflect EMFAC2011 and EPA's 2012 PM NAAQS final rule. The November 2013 guidance supersedes the December 2010 guidance. Please refer to the fact sheet and guidance change bulletin belowfor more information.
Contact: Meg Patulski at 734-214-4842 or firstname.lastname@example.org
Technical questions about this guidance can be directed to email@example.com.
- Main document only (PDF) (160pp, 5.3M, EPA420-B-13-053, November 2013)
- Appendices only (PDF) (134pp, 6.1M)
- Fact Sheet (PDF) (6pp, 253K, EPA420-F-13-049, November 2013)
- Guidance Change Bulletin: November 2013 (PDF) (1p, 491K, EPA420-B-13-056, November 2013)
The two-year grace period for completing quantitative hot-spot analyses using MOVES and EMFAC ended on December 20, 2012; new PM hot-spot conformity analyses required under 40 CFR 93.123(b)(1) started after this date must be quantitative rather than qualitative. See the Federal Register notice (PDF) and EPA’s latest MOVES policy guidance for details.
- Transportation Conformity Guidance for Qualitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas (PDF) (35 pp, 306K, EPA420-B-06-902, March 2006)
The Environmental Protection Agency (EPA) and the Federal Highway Administration (FHWA) developed this guidance to help state and local agencies complete qualitative PM hot-spot analyses, when applicable.
Contact: Meg Patulski at 734-214-4842 or firstname.lastname@example.org
CO Hot-spot Analyses: Guidance
- Using MOVES in Project-Level Carbon Monoxide Analyses (PDF) (59pp, 2M, EPA420-B-10-041, December 2010)
This guidance describes how to use the MOVES emissions model to estimate CO emissions from transportation projects, including roadway intersections, highways, transit projects, parking lots and intermodal terminals. This guidance can be applied when using MOVES to complete any project-level quantitative CO analysis, including hot-spot analyses for transportation conformity determinations, modeling project-level emissions for SIP development, and completing NEPA analyses.
Contact: David Bizot at 734-214-4432 or email@example.com. Technical questions about this guidance can be directed to firstname.lastname@example.org.
The two-year grace period for completing quantitative hot-spot analyses using MOVES and EMFAC ended on December 20, 2012; any new quantitative CO hot-spot conformity analyses started after this date outside of California must be based on MOVES. See the Federal Register notice (PDF) and EPA’s latest MOVES policy guidance for details.
Emissions Models and Methods
- Approved Versions of Emissions Models
The following is a summary of currently approved on-road emissions models for quantitative PM and CO hot-spot conformity analyses. This is only a summary; refer to the appropriate guidance and model websites for more information about the applicability and use of these models.
Emissions Model Geographic Applicability Federal Register Notice of Approval
Link to Model Information MOVES2010a and MOVES2010b All states other than California Official Release of the MOVES2010a and EMFAC2007 Motor Vehicle Emissions Models for Transportation Conformity Hot-Spot Analyses and Availability of Modeling Guidance (PDF) (December 20, 2010) www.epa.gov/otaq/
EMFAC2011 California only Official Release of EMFAC2011 Motor Vehicle Emission Factor Model for Use in the State of California
(March 6, 2013)
EMFAC2007 California only, until Sept. 6, 2013 PM hot-spot analyses (PDF) (December 20, 2010)
CO hot-spot analyses (PDF) (January 18, 2008)
See http://www.epa.gov/otaq/stateresources/transconf/policy.htm#models for more information about EPA’s approvals of models and methods for conformity purposes.
- Estimating Road Dust Emissions
Road or construction dust can be quantified for a PM hot-spot analysis using EPA’s AP-42 method or alternative local methods. AP-42 is EPA’s compilation of data and methods for estimating average emission rates from a variety of activities and sources from various sectors. EPA’s website www.epa.gov/ttn/chief/ap42/index.html has the latest version of AP-42 and more information about AP-42 in general. The sections of AP-42 that address emissions of re-entrained road dust from paved and unpaved roads and emissions of construction dust are found in AP-42, Chapter 13, “Miscellaneous Sources.” The key portions of the chapter include:
- Section 13.2: “Introduction to Fugitive Dust Sources”
- Section 13.2.1: “Paved Roads”
- Section 13.2.2: “Unpaved Roads”
- Section 13.2.3: “Heavy Construction Operations” (includes road construction)
In addition to the latest version of AP-42, alternative local methods can be used for estimating road or construction dust; in some areas, these methods may already exist and can be considered for use in quantitative PM hot-spot analyses. The method used for estimating road dust for an analysis must be evaluated and chosen through the interagency consultation process.
Air Quality (Dispersion) Models
- Recommended Air Quality (Dispersion) Models for PM Hot-spot Analyses
The following is a summary of recommended air quality models for completing PM hot-spot analyses for different types of transportation projects. This is a reproduction of Exhibit 7-2 of the Quantitative PM Hot-spot Guidance.
Type of Project Recommended Model(s) Highway and intersection projects AERMOD, CAL3QHCR Transit, freight, and other terminal projects AERMOD Projects that involve both highway/intersections and terminals, and/or nearby sources AERMOD
See Section 7 of the guidance for complete information on selecting an appropriate air quality model. See below for which model versions are currently approved for regulatory use.
- Approved Versions of Air Quality (Dispersion) Models
The following is a summary of currently approved versions of air quality (dispersion) models for quantitative PM hot-spot analyses, as recommended by EPA’s “Guideline for Air Quality Models” (Appendix W to 40 CFR Part 51). This is only a summary; refer to the appropriate guidance and model websites for more information about the applicability and use of these models. Draft or unapproved versions of models cannot be used to complete hot-spot analyses for regulatory purposes.
Air Quality Model Version/date Link to Model Information AERMOD Version Dated 12345 www.epa.gov/ttn/scram/dispersion_prefrec.htm#aermod CAL3QHCR Version dated 13196 www.epa.gov/ttn/scram/dispersion_prefrec.htm#cal3qhc
Tools for Completing Project-level Analyses
- Tool to generate EMISFACT portion of an AERMOD input file
EPA has developed a MySQL script called “MOVES2AERMOD” to automate the process of generating the EMISFACT portion of an AERMOD input file using MOVES output. The tool is intended to be used as part of a quantitative PM hot-spot analysis and can be run directly through the MOVES GUI. To obtain the tool and for more information, see the MOVES tools page.
- MySQL 24-hour PM2.5 Design Value Script
EPA has developed a MySQL script to calculate design values for the 24-hour PM2.5 NAAQS for PM hot-spot analyses. The readme file in the download package describes how to “install” the tool as well as providing instructions on using it for PM hot-spot analyses. Update of September 2013: This script was updated to eliminate a bug that occurred when modeling certain situations.
- PM25DVScript (ZIP) (16.6M)
Training and Other Resources
- Quantitative PM Hot-spot Analysis Training
EPA and DOT have developed a three-day training course on implementing EPA’s guidance. This technical, hands-on course is geared toward state and local agencies and focuses on using emission models (including EPA's MOVES model) and air quality models (AERMOD and CAL3QHCR) for quantitative PM hot-spot analyses. The PM hot-spot analysis training page provides the latest training materials and other information.
- MOVES Model Information and Training
- The EPA’s MOVES page provides complete information about the model, including downloads, technical guidance, and tools.
- The MOVES listserv provides updates on MOVES and other mobile source emissions models. Sign up here.
- EPA has developed a two-day, hands-on course geared toward state and local agencies who will use MOVES for developing SIPs and regional conformity analyses, as well as a shorter web-based course for people interested in a general overview of MOVES. The MOVES training page contains information about this and other MOVES training information, courses, and webinars.
- Air Quality Model Information
- More information about dispersion models (including AERMOD and CAL3QHCR), meteorology preprocessors, and related tools, guidance, and outreach can be found on EPA’s Support Center for Regulatory Atmospheric Modeling (SCRAM) website.
- The SCRAM RSS feed provides updates on recent posting and additions to the SCRAM website. Sign up here.
- Overview of EPA's Quantitative PM Hot-spot Guidance (PDF) (65pp, 656K, February 2011). This presentation was given during a webinar on February 9, 2011.
- A PM Hot-spot Analysis for a Hypothetical Transportation Project (PDF) (58pp, 2.4M, January, 2012). This presentation, given at the January 2012 TRB annual conference, describes an example PM hot-spot analysis that is based on MOVES, AERMOD, and EPA's PM Hot-spot Guidance.
- Project-Level Modeling in MOVES (PDF) (12 pp, 415K, February, 2011). This presentation, given at the January 2011 TRB annual conference, provides a brief introduction to using MOVES at the project scale.
- Additional conformity-related training information and presentations can be found at www.epa.gov/otaq/stateresources/transconf/training.htm.
Frequently Asked Questions (FAQs)
- EPA FAQs
The following are frequently asked questions about conducting hot-spot analyses for transportation conformity purposes. EPA will update these periodically.
- PM hot-spot Analysis FAQs (PDF) (6 pp, 224K, EPA-420-F-12-082, December 2012)
- Federal Highway Administration PM2.5 FAQs
FHWA has developed a series of FAQs specifically for PM2.5 project-level conformity and hot-spot analyses. These FAQs were coordinated with EPA. The FHWA PM2.5 Project-Level Conformity and Hot-Spot Analyses FAQs webpage has more information.
- EPA Regional Conformity Contacts
EPA regional conformity staff are the primary EPA contacts for project sponsors completing project-level analyses for conformity purposes and should be contacted first for information and questions about these analyses. For the complete list of contacts by region, please see www.epa.gov/otaq/stateresources/transconf/contacts.htm.
- Technical questions about using MOVES for project-level analyses can be directed to email@example.com.
- Other technical questions on completing PM or CO project-level conformity analyses can be directed to firstname.lastname@example.org.
- EPA’s Office of Air Quality Planning and Standards maintains a list of state air quality modeling staff who have experience that may be useful to a project sponsor when completing a hot-spot analysis, including running the selected air quality model and finding representative background data for a project. See OAQPS’s state contacts page for more information.