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Notice to Readers: Ground Water Awareness Week --- March 9--15, 2008

Approximately 40%--45% of persons in the United States depend on ground water for their drinking water supply (1--3), and approximately 15% use their own private wells (2). Each year, the National Ground Water Association sponsors Ground Water Awareness Week to stress the importance of protecting ground water and to focus attention on annual private well maintenance and water testing (4). This year, Ground Water Awareness Week is March 9--15.

U.S. Environmental Protection Agency requirements that protect public drinking-water systems do not apply to privately owned wells (2). Owners of private wells are responsible for ensuring that their well water is safe from contaminants of health concern. Certain contaminants, such as arsenic and radon, can occur naturally in the environment, and their concentration in well water depends highly on the geology of the land around the well (5--8). Other contaminants, such as nitrate, are the result of pollutants from local land use (e.g., application of agricultural fertilizer and runoff from animal feedlots) and problems with nearby wastewater systems.

Private wells should be checked and tested every year for mechanical problems, cleanliness, and the presence of certain contaminants, such as coliform bacteria, nitrates and nitrites, and any other contaminants of local concern, such as arsenic and radon (9--10). A water well systems professional can take steps to ensure delivery of high-quality water from an existing well or, if needed, locate and construct a new well in a safer area.

Well water should be tested more frequently if recurrent incidents of gastrointestinal illness have occurred among household members or a change in the taste, odor, or appearance of the well water has been observed. Additional information about Ground Water Awareness Week, well maintenance, and water testing is available at and


  1. US Census Bureau. Annual estimates of the population for the United States, regions, and states and for Puerto Rico: April 1, 2000 to July 1, 2007 (NST-EST2007-01). Washington, DC: US Census Bureau; 2008. Available at
  2. US Environmental Protection Agency. Private drinking water wells. Washington, DC: US Environmental Protection Agency; 2006. Available at
  3. US Environmental Protection Agency. Factoids: drinking water and ground water statistics for 2005. Washington, DC: US Environmental Protection Agency; 2006. Available at
  4. National Ground Water Association. National Ground Water Awareness Week: March 9--15, 2008. Westerville, OH: National Ground Water Association; 2008. Available at
  5. US Geological Survey. Arsenic in ground water of the United States. Reston, VA: US Geological Survey; 2009. Available at
  6. US Environmental Protection Agency. Arsenic in drinking water. Washington, DC: US Environmental Protection Agency; 2007. Available at
  7. US Environmental Protection Agency. Radon. Washington, DC: US Environmental Protection Agency; 2006. Available at
  8. US Environmental Protection Agency. Consumer factsheet on nitrates/nitrites. Washington, DC: US Environmental Protection Agency; 2006. Available at
  9. National Ground Water Association. Well maintenance: a homeowner's checklist. Westerville, OH: National Ground Water Association; 2008. Available at
  10. National Ground Water Association. Schedule your annual water well check up. Westerville, OH: National Ground Water Association; 2008. Available at

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Date last reviewed: 3/5/2008


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