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Final PM_2.5 Project-Level Conformity Analysis for the Ohio River Bridges Project in Louisville, Kentucky

VII. Conclusion

In summary, based on the analysis, it is determined that the ORB project met all the project-level conformity requirements, and that the proposed ORB project will not cause or contribute to a new violation of the PM_2.5 NAAQS, or increase the frequency or severity of a violation for the following reasons:

• Downtown Area 2020 Worst-Case: The downtown area build 2020 worst-case AADT has been estimated to be 291,400 vehicles per day with 15.7 percent trucks (45,700 trucks per day).
  • As compared against surrogate site 1(current downtown Louisville) - Due to the building of the east end bridge, the downtown area build 2020 worst-case AADT is less than the AADT for surrogate 1(current downtown Louisville). Surrogate site 1 monitor design values are only slightly over the annual standard and 24-hour readings are well below the 24-hour standard. While the percent trucks and daily truck volume for the downtown area build 2020 worst-case are greater than those for surrogate 1, it is still reasonable to conclude that since the emissions from an individual truck will be much less due to technological improvements (implemented vehicle and fuel regulations) and the implementation of various non-road regulations as discussed under the section Emissions Trends, overall emissions for downtown area build 2020 worst-case will be less than for surrogate 1.
  • As compared against surrogate site 2 (Northern Kentucky interstate interchange) - The downtown area 2020 worst-case AADT is slightly over (+31,500) the AADT of surrogate site 2 (Northern Kentucky interstate interchange), but the percent and number of trucks are significantly less than that of surrogate site 2. Surrogate site 2 monitor design value readings are meeting both the annual and 24-hour standards.
  • Build vs. No-build:PM_2.5 emissions are expected to be reduced in the project area, as demonstrated by projected reductions in the regional mobile source emissions analysis, as well as by national projections by EPA reflecting the impacts of national emissions control programs, such as the 2007 Heavy-duty Diesel Rule. In addition, as can be seen in Appendix A, the ORB build scenario will result in less total traffic and truck volumes at the downtown area location in 2020 as compared to the no-action scenario, resulting in lower roadway emissions and lower downwind PM_2.5 concentrations.
  • Therefore, based on a comparison against surrogate site 1 and surrogate site 2, as well as the build vs. no-action, it is reasonable to conclude that the ORB downtown area build 2020 worst-case will not cause or contribute to a new violation of the PM_2.5 NAAQS, or increase the frequency or severity of a violation.
• East End 2014 Worst-Case: The east end build 2014 AADT has been estimated as 53,200. Conservatively assuming the truck percentage to be the same as the overall downtown area average of 11.7 percent results in an estimated 6,200 trucks per day.
  • As compared March 10^th Rule Example - The east end build 2014 worst-case scenario AADT and number of trucks are 50 percent less than the example cited in the preamble to March 10, 2006 rule (71 FR 12491) which cited as "significant" a project on a new highway or expressway with 125,000 AADT and 8 percent trucks.
    
  • As compared against surrogate site 1(current downtown Louisville) - AADT and number of trucks are considerably less than those of surrogate 1(current downtown Louisville). Surrogate site 1 monitor design values are only slightly over the annual standard and are expected to meet the annual standard in 2014. Further, surrogate site 1 monitor readings are well below the 24-hour standard.
    
  • As compared against surrogate site 2 (Northern Kentucky interstate - AADT and number of trucks are considerably less than those of surrogate 2 (Northern Kentucky interstate interchange). Surrogate site 2 monitor design value readings are meeting both the annual and 24-hour standards. Therefore, based on a comparison against the March 10th rule, surrogate 1 and surrogate 2, it is reasonable to conclude that the ORB east end area build 2014 worse-case will not cause or contribute to a new violation of the PM_2.5 NAAQS, or increase the frequency or severity of a violation.
    
• Attainment of both the annual and 24-hour standards: As was discussed earlier, because of the overall downward trend in PM_2.5 emissions, attainment of the annual standard will result in continued attainment of the 24-hour standard as required.