New Concepts for Managing Urban Pollution

Most current pollution management in cities is based on treating pollution at the end-of-the pipe, after pollution is generated. This paradigm worked well for treating municipal sewage and industrial effluents – point sources of pollutants. Pollution from these sources has been greatly reduced since passage of the Clean Water Act in 1972. However, the remaining pollution problem in post-industrial cities is mostly caused by nonpoint sources – runoff from lawns, erosion from construction sites, gradual decomposition of automobiles (e.g., erosion of tire particles containing zinc and brake pad linings with copper), and added road salt from de-icing operations. The next section of this chapter shows why the end-of-pipe paradigm cannot be the primary approach for dealing with these types of pollution and why new approaches are needed. If the traditional end-of-pipe paradigm doesn’t work, what will? I will argue that a new paradigm must be based on analysis of the movement of pollutants through urban ecosystems, an approach sometimes called materials flow analysis (MFA). MFA can be used to identify where a potential pollutant enters an urban ecosystem, how it is transferred from one ecosystem compartment to another, and ultimately, it enters surface or groundwater to become an actual pollutant. As we will see, MFA can be used to guide the development of novel approaches for pollution management: reducing inputs of potentially polluting materials to urban ecosystems, improving the efficiency by which they are utilized for their intended purposes, and recycling them. MFA can also be used to develop strategies to mitigate legacy pol-