CGS NS 202 Lecture Notes - Lecture 9: Silt, Estuary, Sewage Treatment
21 Feb 2017
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Document Summary
Water contamination not an issue when settlements were small and far apart: the solution to pollution is dilution , a stream purifies itself every ten miles . Human population growth, industrial output, and careless waste-management practices turned most rivers into open sewers and lakes into cesspools. Most drainage basins polluted with toxic chemicals, human and animal excrement, heavy metals, pesticides, silt, fertilizers. Controlling water pollution: 1972 tough comprehensive federal program enacted by congress federal. Sources of water pollution: point source pollutants sewage treatment plants, storm sewer outfalls, and industrial discharges; effluent enters waterway at defined location, can be collected and treated, nonpoint sources from broad land areas. Agriculture farmland runoff, manure from livestock facilities, chemical fertilizers and pesticides. Construction activities runoff from construction sites contributes 10-20 times more sediment than agriculture; also carries construction waste materials into waterways. Groundwater contamination: chemical, biological, and radiological contaminants identified in groundwater deposits in recent decades, seepage from waste storage, treatment or disposal facilities.
