Does the NPDES program address nonpoint source pollution?
Yes, it can. As described above, nonpoint source pollution is used to describe many non-discrete methods of conveyance of pollution into a waterway, such as the water that flows over our city streets and agricultural fields. The Clean Water Act allowed for regulation of that type of pollution when it ends up in a ditch or a pipe. That is why we discuss stormwater pollution as a point source, because most of it is collected by the stormdrains, gutters or ditches and sent either through the treatment plants (if the system is combined with the sanitary system) or out to the waters directly. There are ways that nonpoint source pollution, which is otherwise unregulated, can be addressed by NPDES permit conditions. For example, certain management practices (revegetation) can be required onsite that improve receiving water health. We are also seeing another strategy, pollution trading, occasionally built into NPDES permits in order to address nonpoint source pollution. Trading is usually asso
