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Environmental issues in the united states

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Non-point pollution is the leading cause of contamination in American waterways, tainting an estimated 1.3 million miles of streams and rivers.The Total Maximum Daily Load (TMDL) restoration program, initiated by the enactment of the federal Clean Water Act of 1972 is the principal legal solution for state intervention regarding non-point pollution. TMDL specifications require state supervisory bodies to take into account all sources of pollution across a river’s watershed (drainage basin). Watershed is the term used to describe the geographic area of land that drains water to a shared destination (FISWRG, 1998). In other words, the water in an area of land such as rain or melting snow drains to the lowest point then moves through a system of drainage conduits, both underground and on the surface, eventually congregating into streams and rivers on their ultimate journey to the ocean. The watershed of a small stream may be as small as a few hundred acres or, in the case of the Mississippi River, might include thousands of square miles across several states. Watersheds replenish rivers with the pollutants from all along the chain of conduits.As one of many examples, watershed pollution can be illustrated by the deteriorating conditions at Lake Tahoe, the largest mountainous lake in North Americas and the world’s eighth-deepest freshwater body. Its waters were clear, enough so that a person could see objects at depths of more than 100 feet a century ago but the irresponsible use of toxic wastes by developments in surrounding areas have contaminated the lake. Visibility has now fallen to 69 feet, declining at about a foot per year. Environmental scientists advise that the lake’s clearness could be ‘irreversibly doomed’ with many of its fish and wildlife eradicated without extraordinary environmental protection