Achieving adequate BMP`s for stormwater quality management

There is considerable controversy about the technical appropriateness and the cost-effectiveness of requiring cities to control contaminants in urban stormwater discharges to meet state water quality standards equivalent to US EPA numeric chemical water quality criteria. At this time and likely for the next 10 years, urban stormwater discharges will be exempt from regulation to achieve state water quality standards in receiving waters, owing to the high cost to cities of the management of contaminants in the stormwater runoff-discharge so as to prevent exceedances of water quality standards in the receiving waters. Instead of requiring the same degree of contaminant control for stormwater discharges as is required for point-source discharges of municipal and industrial wastewaters, those responsible for urban stormwater discharges will have to implement Best Management Practices (BMP's) for contaminant control. The recommended approach for implementation of BMP's involves the use of site-specific evaluations of what, if any, real problems (use impairment) are caused by stormwater-associated contaminants in the waters receiving that stormwater discharge. From this type of information BMP's can then be developed to control those contaminants in stormwater discharges that are, in fact, impairing the beneficial uses of receiving waters.