GBUAPCD RULE 1232 PROCEDURES DETERM. CO & PM10 CONC.(H-SPOT)
LAST REVISED 11/11/11

§ 1232 Procedures for determining localized CO and PM10 concentrations (hot-spot analysis).

(a) In the following cases, CO hot-spot analyses must be based on the applicable air quality models, data bases, and other requirements specified in 40 CFR part 51 Appendix W ("Guideline on Air Quality Models (Revised)" (1988), supplement A (1987) and supplement B (1993), EPA publication no. 450/2-78-027R), unless, after the interagency consultation process described in § 1206 and with the approval of the EPA Regional Administrator, these models, data bases, and other requirements are determined to be inappropriate:

(1) For projects in or affecting locations, areas, or categories of sites which are identified in the applicable implementation plan as sites of current violation or possible current violation;

(2) For those intersections at Level-of-Service D, E, or F, or those that will change to Level-of-Service D, E, or F because of increased traffic volumes related to a new project in the vicinity;

(3) For any project involving or affecting any of the intersections which the applicable implementation plan identifies as the top three intersections in the nonattainment or maintenance area based on the highest traffic volumes;

(4) For any project involving or affecting any of the intersections which the applicable implementation plan identifies as the top three intersections in the nonattainment or maintenance area based on the worst Level-of-Service; and

(5) Where use of the "Guideline" models is practicable and reasonable given the potential for violations.

(b) In cases other than those described in paragraph (a) of this section, other quantitative methods may be used if they represent reasonable and common professional practice.

(c) CO hot-spot analyses must include the entire project, and may be performed only after the major design features which will significantly impact CO concentrations have been identified. The background concentration can be estimated using the ratio of future to current traffic multiplied by the ratio of future to current emission factors.

(d) PM10 hot-spot analysis must be performed for projects which are located at sites at which violations have been verified by monitoring, and at sites which have essentially identical vehicle and roadway emission and dispersion characteristics (including sites near one at which a violation has been monitored). The projects which require PM10 hot-spot analysis shall be determined through the interagency consultation process required in § 1206. In PM10 nonattainment and maintenance areas, new or expanded bus and rail terminals and transfer points which increase the number of diesel vehicles congregating at a single location require hot-spot analysis. DOT may choose to make a categorical conformity determination on bus and rail terminals or transfer points based on appropriate modeling of various terminal sizes, configurations, and activity levels. (The requirements of this paragraph for quantitative hot-spot analysis shall take effect when EPA releases modeling guidance on this subject and announces in the Federal Register that these requirements are in effect.)

(e) Hot-spot analysis assumptions must be consistent with those in the regional emissions analysis for those inputs which are required for both analyses.

(f) PM10 or CO mitigation or control measures shall be assumed in the hot-spot analysis only where there are written enforceable commitments from the project sponsor or operator to the implementation of such measures, as required by § 1234(a).

(g) CO and PM10 hot-spot analyses are not required to consider construction-related activities which cause temporary increases in emissions. Each site which is affected by construction-related activities shall be considered separately, using established "Guideline" methods. Temporary increases are defined as those which occur only during the construction phase and last five years or less at any individual site.