Sunday, November 06, 2005

DEIS: Air quality concerns; Air quality analysis


Draft EIS states:

The results of the analysis indicate that in the future with the proposed project, there would be no potentially significant adverse air quality impacts from mobile sources.

Maximum predicted 8-hour CO concentrations for the analyzed sites with the proposed traffic mitigation measures would be below the NAAQS and would not result in any significant adverse air quality impacts.

The analysis concludes that the proposed project would not result in significant adverse air quality impacts. The proposed project would increase traffic volumes at a number of intersection locations but would not result in any exceedances of the City’s de minimis criteria or the national ambient air quality standards for carbon monoxide (CO).


The way an air quality analysis is conducted and the assumptions that are used at the beginning of the analysis will greatly impact the results of the analysis. In this case, the air quality analysis was fed flawed information on the assumption that “the existing stadium attracts 320 to 480 more vehicle trips in the peak arrival and departure hours than the proposed stadium would”. Basically, the new stadium would have less cars driving to it (despite more parking spaces) so the air quality impacts would be less.

The air quality analysis should have instead taken the induced demand effect created by the additional parking spaces into account. This induced demand would probably increase traffic to the stadium and as a result, worsen air quality. As such, the air quality analysis should probably be re-done given the fact that an induced demand analysis was not conducted even though the Final Scope of Work said it would on page A-15.


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