By Vince Berg, P.E., Stormceptor Corporation
Since the Clean Water Act (CWA) was created in 1972, clean water programs have tried to make the waters of the United States fishable and swimmable. The focus of these efforts has been on reducing pollutants from industry and municipal wastewater plants.
Section 303(d) of the 1972 CWA deals with "total maximum daily loads" (TMDL). A TMDL is the maximum daily load of a specified pollutant that can be discharged into a given stretch of river, waterway or coastal area, and still ensure the preservation of Water Quality Standards. This concept is regarded as a holistic approach to watershed pollution and makes regulators focus on all pollution sources and their cumulative effects on resources instead of individual problems.
The original CWA required states to develop a list of TMDL impaired water bodies by 1979. If the states failed to do so, then USEPA was supposed to withhold money and then write TMDLs themselves. Despite the law, they were rarely written. When states finally started to implement the TMDL program, the number of impaired water segments increased dramatically. In Idaho, for example, impaired water segments increased from 32 to 960 reaches.
Environmental groups all across the US (27 states) have been initiating lawsuits to require the implementation of the TMDL portion of the CWA and winning. Settlements are requiring states to conduct detailed monitoring evaluations of all waterways and water bodies and to establish a TMDL limit for each. As a result, water quality monitoring programs are being increased nationwide.
As a result of these lawsuits, states and local governments will be required to increase their regulatory emphasis on nonpoint source pollution runoff from cities, suburbs, streets and farms. In the past, the emphasis was placed on point source pollution from industry and wastewater treatment plants. The TMDL criteria are to evaluate all sources of pollution, both point and nonpoint, including background pollution and air pollution. They also provide a factor for safety and a factor for future growth. With this information, the TMDL for the waterway can be established. They also may be written to control toxics (oil/grease, metals, chemicals) as well as nutrients or sediments which impair specific water resources.
Impaired waterways represent 40% of the US's waterways, many of which are in urban areas. It is apparent that a large amount of time and money will be spent writing plans to clean up polluted waterways and waterbodies identified under the TMDL program. A January 1999 court decision in California established time frames to achieve clean-up goals and pollutants to be regulated. The TMDL will require major changes to the way urban stormwater runoff is viewed and the way in which it is discharged to waterways and coastal areas.
There are many uncertainties in the implementation of these programs. Can new permits be issued if a TMDL violation exists? How will those Smart Growth Areas which violate criteria be handled? Will TMDLs force industries to move to areas where they can receive higher discharge load allocations? How will TMDL criteria be enforced, especially nonpoint sources of pollution?
Proponents of TMDL criteria say it is only fair to control nonpoint source pollution. Otherwise, point sources will be required to handle even greater pollution reductions. This would be very costly compared to nonpoint source reductions.
The need for technologies in urban areas to control toxics, sediment, and other urban pollutants to meet TMDL and other CWA requirements will increase.