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
- CO Hot-spot Analyses: FHWA Categorical Finding
- 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 2015: This guidance has been updated to reflect MOVES2014 and its subsequent minor revisions such as MOVES2014a, to revise design value calculations to be more consistent with other EPA programs, and to reflect guidance implementation and experience in the field. Please see the November 2015 guidance change bulletin below for more information.
- Main document only (PDF) (160 pp, 3 MB, EPA-420-B-15-084, November 2015)
- Appendices only (PDF) (82 pp, 1MB, EPA-420-B-15-084-Appendices, November 2015)
- Guidance Change Bulletin: November 2015 (PDF) (3 pp, 182K, EPA-420-B15-090, November 2015)
The two-year grace period for completing quantitative hot-spot analyses using MOVES2014 ends on October 7, 2016; new PM hot-spot conformity analyses required under 40 CFR 93.123(b)(1) started after this date must be based on MOVES2014. See the Federal Register notice (PDF) (5 pp, 230K, published October 7, 2014) and EPA's latest MOVES policy guidance for details.
- Guidance Change Bulletin: November 2013 (PDF) (1 pg, 491K, EPA-420-B-13-056, November 2013)
Previous Guidance Change Bulletins:
CO Hot-spot Analyses: Guidance
- Using MOVES2014 in Project-Level Carbon Monoxide Analyses (PDF) (55 pp, 603K, EPA-420-B-15-028, March 2015)
This guidance describes how to use the MOVES2014 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 MOVES2014 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: Technical questions about this guidance can be directed to firstname.lastname@example.org.
- Using MOVES in Project-Level Carbon Monoxide Analyses (PDF) (59 pp, 2M, EPA-420-B-10-041, December 2010)
Note: Use this guidance instead of the MOVES2014 guidance above if you are using MOVES2010, MOVES2010a, or MOVES2010b for a project-level carbon monoxide analysis. Note that the grace period for MOVES2014 ends on October 7, 2016; any new quantitative CO hot-spot conformity analysis started after this date outside of California must be based on MOVES2014.
Contact: Technical questions about this guidance can be directed to email@example.com.
The two-year grace period for completing quantitative hot-spot analyses using MOVES2014 ends on October 7, 2016; any new quantitative CO hot-spot conformity analyses started after this date outside of California must be based on MOVES2014. See the Federal Register notice (PDF) (5 pp, 230K, published October 7, 2014) and EPA's latest MOVES policy guidance for details.
CO Hot-spot Analyses: FHWA Categorical Finding
- CO Categorical Hot-Spot Finding for Intersection Projects
On February 12, 2014, the Federal Highway Administration (FHWA) announced the availability of a carbon monoxide categorical hot-spot finding for certain projects involving a large urban intersection. Where a project’s parameters fit the conditions of the categorical hot-spot finding, project sponsors may be able to rely on the categorical hot-spot finding in place of doing their own CO hot-spot analysis as part of a project-level conformity determination in CO maintenance areas outside of California. The interagency consultation process should be used to determine whether the CO categorical hot-spot finding applies to a particular project, and any project-level conformity determination that relies on FHWA’s finding would be subject to public involvement requirements (40 CFR 93.105).
- FHWA Memorandum
- FHWA’s CO Categorical Hot-spot Finding
- FHWA’s CO Categorical Hot-spot Finding Technical Documentation
Note: During the MOVES2014 grace period (ending October 7, 2016), a project sponsor may continue to rely on the categorical finding for applicable projects that are determined through interagency consultation to be covered by the finding’s parameters. New CO hot-spot analyses for conformity purposes begun after the end of the grace period may not rely on the February 2014 CO categorical hot-spot finding because the finding was based on MOVES2010.See FHWA’s CO categorical hot-spot finding website for more information about the finding. Questions about applicability of the finding can be addressed to the appropriate EPA Regional staff contact or Meg Patulski at firstname.lastname@example.org.
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 MOVES2014 All states other than California Official Release of the MOVES2014 Motor Vehicle Emissions Model for SIPs and Transportation Conformity (PDF) (5 pp, 230K, published October 7, 2014) www.epa.gov/otaq/models/moves/ 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) (5pp, 174K, published December 20, 2010) www.epa.gov/otaq/models/moves/ EMFAC2011 California only Official Release of EMFAC2011 Motor Vehicle Emission Factor Model for Use in the State of California (March 6, 2013) http://www.arb.ca.gov/msei/modeling.htm
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 14134 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.
- PM Hot-spot Modeling: Lessons Learned in the Field (PDF) (26 pp, 2.4MB, January 2014). This presentation, given at the January 2014 TRB annual conference, covers some of the modeling issues that have arisen in the field and the correct application of the models for hot-spot modeling.
- Overview of EPA's Quantitative PM Hot-spot Guidance (PDF) (31 pp, 4.1MB, October 2014). This general overview was presented several times after the release of the guidance in 2011 and was updated October 2014.
- 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.
- 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.