http://www.washingtonpost.com/wp-dyn/content/article/2006/09/28/AR2006092801994.html/?/ LOL, most of the unwanted bacteria found in the DC area's rivers comes from wildlife sources. Maybe there never was such a thing as a pristine, sustainable, natural environment. Every species, not just humans, alters the environment in which it lives, sometimes in ways that could damage other species.