Bass Pro Mills Dr Extension Municipal Class EA Air Quality Impact Assessment Report

• Although the Project may lead to minor increases of air contaminant concentrations (when compared with Future No Build) at the sensitive receptors within the Study Area of the Project, implementation of the Project is expected to improve the future traffic flow and smoothness (less congestion than the Future No Build scenario) in the local road network and minimize the impact on air quality. [...] For the purpose of this report, the Study Area for the air quality assessment encompasses the Project footprint and the land in a 500 m radius of its boundaries. [...] This is done by considering the implementation of the Project in the Future Build scenario (i.e., in 2031) and comparing this to the predicted future emissions and effects without implementation of the Project (in 2031) referred to as the Future No-Build scenario. [...] The background hourly NO2 concentration is not explicitly compared with the CAAQS as the 1-hour CAAQS for NO2 is referenced to the three-year average of the annual 98 th percentile of the daily maximum one-hour average concentrations while the background concentration is the 90th percentile of hourly values, and therefore the calculation basis for these two parameters are inconsistent. [...] For comparison with the 1-hour NO2 CAAQS, the 98th percentile of the predicted 1-hour NO2 concentrations at the sensitive receptor where the maximum predicted GLC occurs was calculated for each of the five years in the meteorological data set.