Minnesota Department of Transportation

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Project development

Environmental process | Environmental review | Air Quality

Air Quality prepared statements

Conformity determination statement

Regionally significant project (Twin Cities maintenance area)

Use the following statement as appropriate.

The 1990 Clean Air Act Amendments (CAAA) require that State Implementation Plans (SIP) must demonstrate how states with nonattainment and maintenance areas will meet federal air quality standards. The U.S. Environmental Protection Agency (USEPA) has designated all of Hennepin, Ramsey, Anoka and portions of Carver, Scott, Dakota, Washington and Wright counties as a maintenance area for carbon monoxide (CO). This area includes the project area, which is in [blank] County.

The USEPA issued final rules on transportation conformity (40 CFR 93 Subpart A) which describe the methods required to demonstrate State Implementation Plan (SIP) compliance for transportation projects. This project is currently included in [blank] (YEAR) of the [blank] (Year) - [blank] (Year) TIP and in the transportation conformity section of the TPP and/or TIP. On November 8th, 2010, the EPA approved a limited maintenance plan request for the Twin Cities maintenance area. Under a limited maintenance plan, the EPA has determined that there is no requirement to project emissions over the maintenance period and that an emission budget may be treated as essentially not constraining for the length of the maintenance period. The reason is that it is unreasonable to expect that our maintenance area will experience so much growth within this period that a violation of CO National Ambient Air Quality Standard (NAAQS) would result.

Therefore, no regional modeling analysis for the TPP and TIP is required; however federally funded and state funded projects are still subject to “hot- spot” analysis requirements. The limited maintenance plan adopted in 2010 determines that the level of CO emissions and resulting ambient concentrations will continue to demonstrate attainment of CO NAAQS.

This project does not interfere with implementation of any transportation control measure included in the SIP. The TIP was determined to conform to the requirements of the 1990 CAAA by USDOT on Month day, 20xx. The project's design concept and scope are not significantly different from that used in the TIP conformity analyses. As demonstrated by the above information, this project conforms to the requirements of the CAAA and to the Conformity Rules, 40 CFR 93.

Projects exempt from conformity in the Twin Cities CO maintenance areas

Use the following statement if the project is exempt from conformity requirements:

The project is not located in an area in which conformity requirements apply, and the scope of the project does not indicate that air quality impacts would be expected. Therefore, no further air quality analysis is necessary.

or

Although the project is not located in an area in which conformity requirements apply, the project scope is such that air quality impacts are anticipated. Therefore, an air quality analysis has been performed and the results are included as follows.

CO hot spot analysis (Twin Cities CO maintenance areas) statement

Include the results of a CO hot spot analysis screening process in the environmental document with the following statement:

The U.S. Environmental Protection Agency has approved a screening method to determine which intersections need [CO] hot-spot analysis. MnDOT demonstrates by the results of the screening procedure that the intersection(s) does (do) not require [a CO] hot-spot analysis.

Projects types listed in 40 CFR 93.126, .127, .128 statement (exempt)

If the project type is listed in 40 CFR 93.126, or 40 CFR 93.128, the use the following statement:

This project does not require an air quality analysis and is exempt from Environmental Protection Agency (EPA) transportation conformity requirements in 40 CFR 93. Therefore, no air quality analysis related to the NAAQS has been performed.

CO hot spot analysis (Twin Cities carbon monoxide attainment areas) statement

At the time of the project documentation, if the MPO chooses to implement the screening method, the project manager may perform the EPA approved screening method used to meet transportation conformity requirements, which allows a screening procedure to determine which intersections need localized hot spot analysis. The project manager (after consulting with the appropriate MnDOT and MPCA personnel listed on the first page of this document), must include the results of the screening process and the following statement:

The U.S. Environmental Protection Agency has approved a screening method to determine which intersections need [CO] hot-spot analysis. MnDOT demonstrates by the results of the screening procedure that the intersection(s) does (do) not require [a CO] hot-spot analysis.

If the above mentioned screening procedure is used and demonstrates that the intersection does require a hot spot intersection analysis, the project manager must consult with the appropriate MnDOT and MPCA personnel listed on the first page of this document to determine the procedures and dates to be used for the CO hot spot analysis. Include the results of the analysis in the project documentation.

Mobile Source Air Toxics (MSATs) statement

Refer to the Updated Interim Guidance on Mobile Source Air Toxic Analysis in NEPA Documents

The purpose of this project is to (insert major deficiency that the project is meant to address) by constructing (insert major elements of the project). This project has been determined to generate minimal air quality impacts for Clean Air Act criteria pollutants and has not been linked with any special mobile source air toxic (MSAT) concerns. As such, this project will not result in changes in traffic volumes, vehicle mix, basic project location, or any other factor that would cause a meaningful increase in MSAT impacts of the project from that of the no-build alternative.

Moreover, Environmental Protection Agency (EPA) regulations for vehicle engines and fuels will cause overall MSAT emissions to decline significantly over the next several decades. Based on regulations now in effect, an analysis of national trends with EPA’s MOVES2014 model forecasts a combined reduction of over 90 percent in the total annual emissions rate for the priority MSAT from 2010 to 2050 while vehicle-miles of travel are projected to increase by over 45 percent (Updated Interim Guidance on Mobile Source Air Toxic Analysis in NEPA Documents, Federal Highway Administration, October 12, 2016). This will both reduce the background level of MSAT as well as the possibility of even minor MSAT emissions from this project.