Current through August 26, 2024
(1) The analyses required under this chapter
shall be based on the latest planning assumptions.
(a) All planning assumptions, including, but
not limited to, per capita water and sewer use, vehicle miles traveled per
capita or per household, trip generation per household, vehicle occupancy,
household size, vehicle fleet mix, vehicle ownership, wood stoves per
household, and the geographic distribution of population growth, shall be
derived from the estimates of current and future population, employment, travel
and congestion most recently developed by the MPO, or other agency authorized
to make such estimates for the area. The conformity determination shall also be
based on assumptions and estimates about current and future background
concentrations that are included in the current applicable implementation plan
and based on the latest assumptions and estimates about other federal
actions.
(b) Any revisions to these
estimates used as part of the conformity determination, including projected
shifts in geographic location or level of population, employment, travel and
congestion, shall be approved by the MPO or other agency authorized to make
such estimates for the area.
(2) The analyses required under this chapter
shall be based on the latest and most accurate emission estimation techniques
available as described below, unless such techniques are inappropriate. If such
techniques are inappropriate and written approval of the EPA regional
administrator is obtained for any modification or substitution, they may be
modified or another technique substituted on a case-by-case basis or, where
appropriate, on a generic basis for a specific federal agency program.
(a) For motor vehicle emissions, the most
current version of the motor vehicle emissions model specified by EPA for use
in the preparation or revision of implementation plans in the state or area
shall be used for the conformity analysis as specified below in subds. 1. and
2.:
1. A new motor vehicle emissions model
shall be used after EPA publishes in the federal register a notice of its
availability.
2. A grace period of
3 months shall apply during which the motor vehicle emissions model previously
specified by EPA as the most current version may be used. Conformity analyses
for which the analysis was begun during the grace period or no more than 3
years before the federal register notice of availability of the latest emission
model may continue to use the previous version of the model specified by EPA,
if a final determination as to conformity is made within 3 years of such
analysis.
(b) For
non-motor vehicle sources, including stationary and area source emissions, the
latest emission factors specified by EPA in the Compilation of Air Pollutant
Emission Factors, AP-42, incorporated by reference in s.
NR 484.05, shall be used for the conformity analysis
unless more accurate emission data are available, such as actual stack test
data from stationary sources which are part of the conformity
analysis.
(3) The air
quality modeling analyses required under this chapter shall be based on the
applicable air quality models, databases, and other requirements specified in
the most recent version of the Guideline on Air Quality Models in Appendix W of
40 CFR part 51, incorporated by reference in s.
NR 484.04, unless:
(a)
The guideline techniques are inappropriate, in which case the model may be
modified or another model substituted on a case-by-case basis or, where
appropriate, on a generic basis for a specific federal agency program;
and
(b) Written approval of the
administrator is obtained for any modification or substitution.
(4) The analyses required under
this chapter shall be based on the total of direct and indirect emissions from
the action and shall reflect emission scenarios that are expected to occur
under each of the following cases:
(a) The act
mandated attainment year or, if applicable, the last year for which emissions
are projected in the maintenance plan;
(b) The year during which the total of direct
and indirect emissions from the action for each pollutant analyzed is expected
to be the greatest on an annual basis; and
(c) Any year for which the applicable
implementation plan specifies an emissions budget.
