40 CFR §93.101Definitions.
Donut areas are geographic areas outside a metropolitan planning area boundary, but inside the boundary of a nonattainment or maintenance area that contains any part of a metropolitan area(s). These areas are not isolated rural nonattainment and maintenance areas.
Conformity determinations by an MPO must consider emissions from all projects in the nonattainment or maintenance area, including projects located in a donut area. Thus, the metropolitan planning process must address the donut area in some manner during the development of a plan, TIP, and regional emissions analysis.
Given this background, possible options for donut area project conformity analysis and determinations are presented below. The details shown below are largely based on guidance regarding donut areas that is contained in the preamble to the 1993 conformity rule.
58 FR 62207,62208, November 24, 1993
Because an MPO must consider in its regional analysis of transportation plans and TIPs all highway and transit projects in the nonattainment or maintenance area, the MPO and State DOT may choose to include donut area projects in the transportation plan/TIP. In such cases, no further regional analysis of such projects would be necessary.
If projects in donut areas are not specifically included in the transportation plan/TIP, the project level conformity determination would have to document that such projects were included in the original regional emissions analysis used to demonstrate conformity of the existing transportation plan/TIP.
Another option is to perform a complete new analysis in which the project is hypothetically assumed to be added to the transportation plan/TIP, and the combination is tested to see if it would satisfy all the conformity criteria for transportation plans and TIPs. If it would, the project may be found to conform. EPA notes that this re-analysis must use the latest planning assumptions and emissions model, which may have changed since the TIP was adopted.
Of the three options, EPA believes that all parties involved will be better served by pursuing the first or second option. (emphasis added)
The transportation conformity rule also requires that the interagency consultation process as discussed in Chapter 2 and defined in the conformity SIP be used for conformity determinations in donut areas.
The regional emissions analysis that MPOs base their transportation plan and TIP conformity determinations on must include the entire nonattainment or maintenance area (unless there are adequate/approved subarea budgets) (See 40 CFR §93.122(a)(1) and (7)). This can be accomplished in different ways. The conformity rule requires that interagency consultation procedures include specific procedures for where the metropolitan planning area does not include the entire nonattainment or maintenance area, including a process involving the MPO and the State DOT for cooperative planning and analysis for purposes of determining conformity of all projects outside the metropolitan area, but within the nonattainment or maintenance area. (See 40 CFR §93.105(c)(3))
In some existing nonattainment/maintenance areas with these "donut" areas, the MPO takes the lead in conducting the regional emissions analysis for the donut area. However, in many other nonattainment and maintenance areas with donut areas, the State DOT takes the lead for regional emissions analysis for the area that falls outside of the MPO planning area but within the nonattainment or maintenance area.
In cases where different boundary definitions do exist, there are three options for conducting conformity determinations for donut area projects as part of an overall regional emissions analysis. These options are discussed in the preamble language above and summarized in Exhibit 12-1. The particular analysis option to be used in each donut area will be determined through the interagency consultation process. For examples of how donut areas have conducted the regional emissions analysis see: /environment/air_quality/conformity/policy_and_guidance/complex_areas/.
|Option (to be determined through the interagency consultation process)||Action|
||No further regional analysis of the projects is necessary because the donut area projects were included in the conformity analysis for the plan/TIP.|
||Document that such projects were included in regional emissions analysis.|
||Redo regional emissions analysis using latest planning assumptions and emissions models, which may have changed since the TIP was adopted.|
Is a project that is located in a donut area subject to conformity requirements?
Yes, a conformity determination and regional emissions analysis is required for projects in donut areas, as described above. In addition, a hot-spot analysis must be performed on all non-exempt projects that are located in donut areas contained in CO or PM10 nonattainment or maintenance areas. Such projects also need to be included in the STIP and complete all NEPA requirements prior to funding or implementation.
When a non-exempt project is located in a donut area, the municipality for that area has its own transportation model, and the MPO has a regional transportation model (with little or no detail for the donut area municipality), how should regional conformity and related hot-spot analysis for that project be performed?
First of all, the interagency consultation process should be used to decide which modeling approach should be used. The project must be reflected in the regional conformity analysis supporting the metropolitan plan/TIP.
In addition, if the project is located within a CO nonattainment area, a hot spot analysis must be performed (See Chapter 14). The travel data to be used in the analysis should come from the more detailed model (either the donut area model or the MPO model). However, if that data comes from the donut area model, the volumes used in the hot-spot analysis should be compared with those used in the regional analysis of the plan/TIP (the MPO model) to ensure that the volumes are consistent.
Do the conformity examples included in the rule for "isolated rural" nonattainment and maintenance areas apply to donut areas?
No. The rule does not consider donut areas to be isolated rural areas, since projects in such donut areas must be considered in the context of the MPO's plan/TIP.
A regionally significant project has been proposed in a donut area for which no forecasts of travel activity are available. How can conformity be determined for the project?
Interagency consultation between the MPO and the State department of transportation is to be used to determine the cooperative planning and analysis process that will be used for the conformity determination. The actual process that is used is likely to depend on whether the MPO has network modeling capability to include the estimated impacts of the project. If so, the network modeling capabilities must be used. If the network modeling requirements do not apply then the transportation conformity rule (40 CFR §93.122(a)(7)) calls for "reasonable methods" for VMT estimation on off-model network roadways within the urban transportation planning areas and roadways outside the urban transportation planning area.
As defined in the conformity rule, clean data means:
40 CFR §93.101, Definitions
Clean data means air quality monitoring data determined by EPA to meet the requirements of 40 CFR part 58 that indicate attainment of the national ambient air quality standard.
The transportation conformity rule provides additional flexibility for clean data ozone areas as discussed below.
40 CFR §93.109(d)(5)
Notwithstanding paragraphs (d)(1) and (d)(2) of this section, ozone nonattainment areas with three years of clean data for the 8-hour ozone NAAQS that have not submitted a maintenance plan and that EPA has determined are not subject to the Clean Air Act reasonable further progress and attainment demonstration requirements for the 8-hour ozone NAAQS must satisfy one of the following requirements:
40 CFR §93.109(e)(4)
Notwithstanding paragraphs (e)(1) and (e)(2) of this section, ozone nonattainment areas with three years of clean data for the 8-hour ozone NAAQS that have not submitted a maintenance plan and that EPA has determined are not subject to the Clean Air Act reasonable further progress and attainment demonstration requirements for the 8-hour ozone NAAQS must satisfy one of the following requirements:
Clean data areas are moderate and above ozone areas with three years of clean data for the 8-hour ozone standard that have not submitted a maintenance plan and for which EPA believes it is reasonable to interpret the Clean Air Act's reasonable further progress and attainment demonstration requirements so as not to require areas that are meeting the ozone standard to make certain SIP submissions. In addition, some subpart 1 areas may also be eligible for the clean data policy if they are required to submit control strategy SIPs. Areas that qualify for EPA's clean data policy under the 8-hour standard can use on options listed below to complete the regional emissions analysis. (69 FR 40019, July 1, 2004)
Conformity requirements for clean data areas that are not required to submit SIPs per EPA rulemaking are summarized in Exhibit 12-32. As shown in the Exhibit, clean data areas are allowed to choose one of three options to demonstrate conformity.
Clean data areas can use any one of the following tests to determine conformity:
An EPA-approved clean data area is allowed to use the motor vehicle emissions in the most recent year of clean data as a motor vehicle emissions budget. Must EPA approve this motor vehicle emissions budget before it can be used for transportation conformity purposes?
Yes. An emissions budget for conformity purposes in clean data areas can only be established through the EPA rulemaking that determines an area has clean data. Alternatively, an area can submit an emissions budget to EPA for approval as part of the regular SIP revision rulemaking process and that budget can be used after EPA has made an adequacy determination (40 CFR, 62 FR 43785, Aug. 15, 1997). Clean data areas may also use the interim emissions test flexibility as shown in Exhibit 12-2 above, if an adequate budget does not exist.
Can an area for which EPA has already completed a clean data rulemaking use the motor vehicle emissions in the most recent year with clean data as an emissions budget?
No, the area cannot use the budget for transportation conformity purposes unless the area establishes an emissions budget through the SIP process. However, the area can choose to submit a SIP budget and base the budget on a demonstration of clean data (rather than modeling). In such a case, the budget can be the motor vehicle emissions in the most recent year of clean data.
If an approved motor vehicle emissions budget is based on clean data, what happens if subsequent years have NAAQS violations?
If a budget was established through the SIP process, the EPA can issue a SIP call. If the SIP has not yet been approved, EPA can declare the submitted budget inadequate during the adequacy review. EPA also has the ability to disapprove a submitted SIP based on clean data if violations occur prior to approval. Under any of these scenarios, the area will need to submit a SIP revision containing a new emissions budget.
 40 CFR §§93.116, 93.123 - EPA issued PM2.5 and revised PM10 hot spot analyses requirements in March 2006. This Guide has not been updated to reflect those changes.