Skip directly to: content | left navigation | search
  1. Home ›
  2. Water Quality

Water Quality

    man and boy at lakePoorly planned growth and the subsequent loss of green space that often accompanies it can affect both surface and groundwater quality. In the natural environment, rainfall is either intercepted by vegetation or percolates slowly through the soil to receiving waters.

    In urbanized areas, rainfall that once filtered slowly downhill becomes surface runoff. This water flows across compacted earth and impervious human-made surfaces, such as asphalt, concrete, and rooftops, and is channeled into storm drains.

    This disruption of the natural hydrologic cycle causes stormwater runoff to reach streams and rivers more quickly than these water bodies can absorb it, and often before pollutants can be filtered through the ground. Undisturbed forested lands generally have the highest capacity to absorb water; thus, these areas have the lowest rates of stormwater runoff. In contrast, impervious surfaces such as concrete have the highest runoff rates. The volume of stormwater that washes off 1-acre parking lots is about 16 times greater than the volume that runs off a comparable-sized meadow. This increased runoff causes increased erosion and stream siltation and may affect water treatment plants.

    An additional threat to water quality posed by uncontrolled growth is the overuse of septic systems in low-density suburban and rural residential developments. Overuse of a septic system can result in groundwater contamination, potentially affecting the health of all people coming into contact with the water source.

    For more information on water quality, refer to the following resources:

    • Center for Watershed Protection
      (http://www.cwp.org )
      The Center for Watershed Protection is a nonprofit 501(c)3 corporation that provides local governments, activists, and watershed organizations around the country with the technical tools for protecting some of the nation’s most precious natural resources: our streams, lakes, and rivers.


    • The Stormwater Manager’s Resource Center (SMRC)
      (http://www.stormwatercenter.net)
      The Stormwater Manager's Resource Center is designed specifically for stormwater practitioners, local government officials, and others who need technical assistance on stormwater management issues. Created and maintained by the Center for Watershed Protection, SMRC has everything you need to know about stormwater in a single site.


    • EPA’s Office of Water
      (http://www.epa.gov/OW/)
      The U.S. Environmental Protection Agency’s Office of Water activities are targeted to prevent pollution wherever possible and to reduce risk for people and ecosystems in the most cost-effective ways possible.


    • National Center for Infectious Diseases –- Waterborne Diseases
      (http://www.cdc.gov/ncidod/diseases/list_waterborne.htm)
      Provides information on the different types of waterborne diseases as well as links to additional external resources.

    Additional information on water quality and related topics can be found in the Additional Resources section.
     

    References
    Schueler, TR, Holland, HK, editors. Why stormwater matters. The practice of watershed protection: an edited anthology. Article 63. Center for Watershed Protection; Maryland: 2000.


    Disclaimer: Links to non-federal organizations found at this site are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the federal government, and none should be inferred. CDC is not responsible for the content of the individual organization Web pages found at these links.

    top