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has no point source discharges of pollution. Of the 19,600 <br /> acres in the University Lake watershed, only 8% is considered <br /> developed. The Little River, Flat River, Back Creek, and <br /> Upper Eno watersheds are likewise rural in nature and free <br /> from potential concentrated sources of pollution. Durham has <br /> requested a WS-I classification for the Little River and Flat <br /> River watersheds, while Graham-Mebane has requested a WS-I <br /> classification for the Back Creek watershed. The water <br /> quality from these watersheds is considered good. <br /> The sources of pollution which have been discussed so far, <br /> are called "point sources" of pollutants. Point source <br /> refers to pollutants from a specific fixed source which <br /> enters the water at an identifiable point. An example would <br /> be the outfall pipe from a sewage treatment plant. Other <br /> sources of pollution are called "non-point sources. " These <br /> are pollutants which reach receiving streams in a diffuse <br /> manner and cannot be attributed to an identifiable or <br /> specific source. An example is the pollutants that accumulate <br /> on a parking lot or road and are washed off in a storm. <br /> Studies around the nation have revealed that non-point <br /> sources of pollution are equally, 'if not more important, <br /> contributors to poor water quality than point sources. <br /> The same studies reveal that non-point source pollution <br /> generation is a function of land use. Areas which are mostly <br /> forested have the lowest amounts of pollutants in the water <br /> that runs off the land. This is because forested areas have a <br /> greater ability to assimilate pollutants present in the <br /> runoff and lack the urban activities, such as concentrated <br /> automobile usage, that produces pollutants. . <br /> In a forested area, only a small percentage of the <br /> precipitation which falls washes off the land into the <br /> nearest stream. The ground cover in forested areas slows the <br /> velocity of runoff and allows water to infiltrate into the <br /> soil' where bacterial and chemical processes can change or <br /> trap pollutants. <br /> As a watershed becomes increasingly urbanized, this situation <br /> changes dramatically. The activities which generate <br /> pollutants are increasingly present in the watershed. The <br /> natural processes of the land and water which can act to <br /> block pollutants from reaching the water supply are greatly <br /> reduced. <br /> One characteristic common to developing areas is that the <br /> percentage of impervious cover increases as development <br /> 2.3 text 9 <br />