Michael Blackhurst, Ph.D., Research Development Manager, Urban and Regional Analysis Program, University of Pittsburgh Center for Social and Urban Research
The Pittsburgh region is served by a combined sewer, which collects, conveys, and partially treats both stormwater and wastewater in the same infrastructure system. During periods of heavy rainfall, stormwater can exceed the capacity of combined sewers, which causes overflow into nearby rivers and streams. While these combined sewer overflows (CSOs) mitigate upstream flooding, they release untreated wastewater into receiving water bodies. Improvements to “gray” infrastructure – pipes, pumps, storage, and treatment facilities – can increase the capacity of the collection system to accommodate more severe wet weather events, but “green” infrastructure includes features that reduce the stormwater entering the collection system by retaining or diverting stormwater. This project works towards a comprehensive green infrastructure strategy by identifying broad areas appropriate for green infrastructure, given variation in hydrologic (land use plus topography) and hydraulic (the capacity of pipes, pumps, and treatment), then applying a mix of additional criteria to target specific installations. A demonstration of green infrastructure siting and cost effectiveness is demonstrated through in an interactive mapping project.
Visit the map – Recommended Siting of Green Infrastructure by Type in Allegheny County: http://sb.ucsur.pitt.edu/steve/green/index.html