NCPA - National Center for Policy Analysis


September 29, 2006

States like Virginia and Maryland have determined that wildlife waste plays a significant role in water pollution.  In the Washington area, violations of the bacteria standards have put more than two dozen streams, including the Potomac and Anacostia rivers, on the federal "impaired waters" list; that means they do not meet the ideal conditions for swimming and need cleaning up.

So who -- or what -- is responsible for the contamination?  The answer has become much clearer in the past five or so years, because of high-tech tests sponsored by states that pinpoint from which animal a particular sample of bacteria came.

In this area, some of what these surveys have found is not surprising:

  • One recent study by a Virginia Tech team found that humans are responsible for 24 percent of the bacteria in the Anacostia and 16 percent of the Potomac's, whether the source is a broken septic tank or the District's large sewage overflows during heavy rains.
  • Livestock were also a major problem around the area -- responsible for 10 percent of the Potomac's bacteria, for instance -- because their manure washes out of pastures and the farm fields where it is spread as fertilizer.

Then there are nature's own polluters:

  • In the Potomac and the Anacostia, for instance, more than half of the bacteria in the streams came from wild creatures.
  • Environmental Protection Agency documents show that similar problems were found in Maryland, where wildlife were more of a problem than humans and livestock combined in the Magothy River, and in Northern Virginia tributaries such as Accotink Creek, where geese were responsible for 24 percent of bacteria, as opposed to 20 percent attributable to people.

Source: David A. Fahrenthold, "Wildlife Waste Is Major Water Polluter, Studies Say," Washington Post, September 29, 2006.

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