Air Quality Toolkit

The Clean Air Act (CAA), the National Environmental Policy Act (NEPA) and the Federal-Aid Highways Code regulate the potential effects caused by proposed transportation projects on air quality in Texas.

Use the following tools to document project-level compliance with laws, regulations and guidance.

Questions? Contact the Air Quality Section of the Environmental Affairs Division at (512) 416-2659.

You may download the software (Tools and Plug-Ins) needed to access forms or view frequently asked questions (Online Forms FAQs).

General Tools
Conformity
Hot-Spot Analysis
Mobile Source Air Toxics (MSAT)
Carbon Monoxide (CO) Traffic Air Quality Analysis (TAQA)
Additional Resources

Date	General Tools	Description
02/19	Frequently Asked Questions – Air Quality	Answers commonly asked questions concerning project-level compliance with transportation-related air quality requirements.
05/17	Air Quality Compliance Flowchart for FHWA/FTA and State-Only Projects	Outlines the steps to comply with the Clean Air Act (CAA), NEPA and the Federal-Aid Highways Code in regards to potential project effects on air quality
05/17	Air Quality Compliance Flowchart for Other Federal Projects	Outlines the steps to comply with the CAA, NEPA and the Federal-Aid Highways Code in regards to potential project effects on air quality
05/17	Environmental Handbook for Air Quality	Outlines the steps to comply with the CAA, NEPA and the Federal-Aid Highways Code in regards to potential project effects on air quality
08/19	Guidance for Preparing Air Quality Statements	Contains the applicable finding and negative declaration statements for documenting air quality compliance with applicable laws, regulations and guidance

Date	Conformity	Description
11/19	Texas Air Quality Nonattainment or Attainment-Maintenance Areas and Counties – Nov. 22, 2019	Provides tabular information on nonattainment/maintenance counties and transportation plan conformity dates
02/14	Review Standard for a Conformity Report	Verifies that a project-level conformity report meets requirements
11/15	Transportation Conformity Report Form	Used to prepare the conformity report
06/16	Useful Information: General Conformity De Minimis and Analysis Emission Rate Lookup Table (ERLT)	Information on the use and development of the ERLT for General De Minimis
06/16	ERLT for General Conformity	Provides tabular emission rates for criteria pollutants.

Date	Hot-Spot Analysis	Description
02/14	Review Standard for a Hot-Spot Analysis Technical Report	Verifies that a Hot-Spot Analysis report meets requirements
02/14	Documentation Standard for a Hot-Spot Analysis Technical Report	Lists the required sections and components of a Hot-Spot Analysis Technical Report
02/14	Hot-Spot Pre-Analysis Consensus Form	After an air quality concern has been identified, the project sponsor provides this form to the consultation partners during the initial conference call. The consultation partners use the data to decide whether the methodology and input parameters are appropriate.
03/19	Decision Form: Project of Local Air Quality Concern (POAQC)	After a metropolitan planning organization (MPO) schedules a conference call, the project sponsor completes and sends this form to partners to determine whether the proposed project is "of air quality concern"

Date	Mobile Source Air Toxics (MSAT)	Description
01/17	Useful Information: Mobile Source Air Toxics (MSAT) Emission Rate Look-up Tables (ERLT)	Information on the use and development of the ERLT for the quantitative MSAT analysis
01/17	ERLT for MSAT	Provides tabular emission rates for criteria pollutants.
09/14	Documentation Standard for Quantitative MSAT Technical Report	Used to prepare a quantitative MSAT technical report for TxDOT projects
09/15	Review Standard for Quantitative MSAT Technical Report	Used by TxDOT to review a quantitative MSAT technical report for TxDOT projects

Date	Carbon Monoxide (CO) Traffic Air Quality Analysis (TAQA)	Description
06/16	Useful Information: Carbon Monoxide (CO) Traffic Air Quality Analysis (TAQA) Emission Rate Look-up Tables (ERLT)	Information on the use and development of the ERLT for TAQA
06/16	ERLT for TAQA	Provides tabular emission rates for criteria pollutants
09/15	Documentation Standard for a CO TAQA Technical Report	Used to prepare a CO TAQA technical report
09/15	Review Standard for CO TAQA Technical Report	Used by TxDOT to review a CO TAQA technical report for TxDOT projects

Date	Additional Resources	Description
10/19	Influence of Roadway Emissions on Near-Road PM2.5: Monitoring Data Analysis and Implications for Determining Transportation Projects of Local Air Quality Concern (POAQC)	Identifies the influence of roadways on near-road PM2.5 emissions
	Aviation Emissions and Air Quality Handbook	Explains Federal Aviation Administration (FAA) air quality guidelines and procedures for projects involving civilian airports and air force bases when FAA is the lead federal agency
	Determining Conformity of Federal Actions to State or Federal Implementation Plans (40 CFR 93)	EPA-administered code implementing Section 176(c) of the CAA (42 USC 7401) and the related requirements of 23 USC 109(j) and establishing policy, criteria and procedures to demonstrate and ensure project conformity with an implementation plan developed pursuant to Section 110 and Part D of the CAA
	Supplement to Jan. 28, 2008 Transportation Planning Requirements and their Relationship to NEPA Process Completion (02/09/11) Distribution Memo	Provides a detailed description of how transportation planning relates to the NEPA process (i.e., project-level consistency and conformity)
	Transportation Conformity: A Basic Guide for State and Local Officials	Provides FHWA's high-level overview of transportation conformity and how requirements relate to transportation investments and the implications on metropolitan transportation plans, transportation improvement programs and transportation projects
	Transportation Conformity Brochure	FHWA answers to basic questions about transportation conformity
	Transportation Conformity Guidance for Qualitative Hot-Spot Analysis in PM2.5 and PM10 Nonattainment and Maintenance Areas Memorandum	FHWA provides guidance for qualitative PM hot-spot analyses for projects of “air quality concern” in PM nonattainment/maintenance areas where a hot-spot analysis started prior to December 2012
	Transportation Conformity Guidance for Quantitative Hot-Spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas	EPA guidance for quantitative PM hot-spot analyses for projects of “air quality concern” in PM nonattainment/maintenance areas where a hot-spot analysis is started post December 2012
	Guidelines for Modeling Carbon Monoxide from Roadway Intersections	EPA guidance on how to model CO at roadway intersections for CO hot-spot analyses
	Using MOVES in Project-Level Carbon Monoxide Analyses	EPA guidance for using its mobile vehicle emission simulator (MOVES) emission model rather than the older MOBILE emissions model in CO hot-spot analyses where the analysis was started post December 2012
	FHWA Technical Advisory for Preparing and Processing Environmental and Section 4(f) Documents T 6640A	FHWA guidance on preparing environmental documents outlining the requirements for performing a CO TAQA and disclosing construction emissions under NEPA
	Interim Guidance Update on Mobile Source Air Toxic Analysis in NEPA Memorandum	Provides an update to FHWA guidance on MSAT analyses
	A Methodology for Evaluating Mobile Source Air Toxic Emissions Among Transportation Project Alternatives	Detailed guidelines on performing quantitative MSAT analysis
	Frequently Asked Questions (FAQ) Conducting Quantitative MSAT Analysis for FHWA NEPA Documents	Provides FHWA recommendations for project sponsors using MOVES for NEPA MSAT analysis concerning defining the scope of MOVES work, gathering input data, and post-processing results

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