it for waste disposal. At least 37 percent of the United States' population resides along the coast, mostly in urban areas. More than 1,400 municipal wastewater treatment plants provide service to the coastal population, discharging 10 billion gallons of treated effluent per day. During the period from 1972 to 1992, about $76 billion were spent in constructing or expanding publicly owned treatment works; $50 billion of this total came from federal grants. At an estimated operating cost ranging from $300 to $500 per million gallons of treated effluent, the national expenditure for operating these plants is between $1.1 billion and $1.8 billion per year.
The management of wastewater and stormwater in coastal urban areas takes place in the context of a multitude of other human activities and natural processes within the coastal zone. Some major factors that cause perturbations in the coastal zone include, in no special order, municipal wastewater and stormwater discharges; combined sewer overflows; other urban runoff; direct industrial wastewater discharges; agricultural runoff; atmospheric deposition; ground water flow; boating traffic; shipping; dredging and filling; leaching of contaminated sediments; oil and gas production; introduction of nonindigenous species; harvesting of fish and shellfish; freshwater impoundment and diversion; and land-use changes in coastal drainage basins.
While treatment plant and outfall technologies often dominate discussions of wastewater issues, they are only two of many important pieces that together make up a coastal wastewater management strategy. Other, less visible components of a management strategy include source control efforts to discourage the production of undesirable wastes and prevent their introduction into wastewater and stormwater drainage systems; education to encourage changes in behavior such as appropriate methods for disposal of automobile oil; monitoring to assure compliance and ascertain the effectiveness of management strategies; and environmental studies to improve understanding of the impact of wastewater management strategies and point toward opportunities for improvement. Water conservation and reclamation programs also can be important components of an integrated strategy.
Current wastewater and stormwater management policies are rooted in the 1972 amendments to the Federal Water Pollution Control Act, reauthorized in 1977 and 1987 as the Clean Water Act. The 1972 act set the nation on a fundamentally new course for protecting its waters. It asserted federal