Results of Modeling the Air Quality Impact of a Proposed Parking Garage in Baltimore, Maryland

摘要

The city of Baltimore is planning to build a 13-story, 504-space parking garage along St. Paul Place in order to alleviate the severe parking space shortage in the central business district of Baltimore, Maryland. Because of opposition from community groups and adjacent property owners that are citing air quality as a concern, a study was commissioned by the city in order to assess the potential air quality impacts of the traffic activity associated with constructing the proposed parking garage. Because of its hot-pot nature, carbon monoxide (CO) was studied. Worst case ambient concentrations of CO contributed by the traffic patterns associated with constructing the proposed parking garage were predicted by modeling the St. Paul Place/St Paul Street/Lexington Street intersection and the proposed parking garage itself The predicted maximum 1-hr average and 8-hr average ground-level CO concentrations generated at the intersection were 6.80 ppm and 4.76 ppm respectively for the existing traffic conditions. For the future conditions, when the garage would be fully operational, they were 7.70 ppm and 5.39 ppm respectively, representing an increase of only 13% over the existing conditions. The predicted maximum 1-hr average and 8-hr average ground-level CO concentrations contributed by the proposed parking garage were 3.56 ppm and 1.81 ppm respectively. At the heights of the adjacent building air intake vents, the predicted maximum concentrations were much lower. In both modeling cases, the results indicate that the traffic patterns associated with constructing the proposed parking garage would have minimal impacts on CO concentrations in the direct vicinities of the proposed parking garage because of the relatively low increase in CO concentrations and also because the predicted maximum CO concentrations were below the health-based CO standards. The results obtained in this study are very significant in terms of urban planning and development. They demonstrate how unique modeling techniques can be utilized as an effective planning tool for addressing air quality impacts associated with urban development and revitalization projects. In this case, it allowed for the approval of a major parking facility that was destined to enter a long litigation process if air quality impacts were not quantified.