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Private Water Systems

Illustration of Individual Water Systems which are divided into two areas. The first area is the use of non-public sources such as ponds, streams or bottled water and the second areas is privately-owned home or farm wells, springs, or surface water sources.

According to the U.S. Environmental Protection Agency (EPA), individual water systems consist of the use of nonpublic sources and private water systems.

  • The use of nonpublic sources consist of using bottled water or water from springs, streams, ponds, and shallow wells not intended for drinking.
  • Private, or individual, water systems are composed of private ground water residential wells, cisterns, and larger private water systems that serve more than one residence.
    • Private ground water wells usually supply water to an individual residence.
    • Private water systems are those that serve no more than 25 people at least 60 days of the year and have no more than 15 service connections (varies by state). Each building serviced by the same private water system is considered to be a service connection for that system. Most private water systems use ground water wells.

Many people in the United States receive their water from private ground water wells.

EPA regulations that protect public drinking water systems do not apply to privately owned wells or any other individual water system, such as rainwater collection. As a result, owners of individual water systems are responsible for ensuring that their water is safe from contaminants.

*1971-2010; Ordered from highest to lowest frequency (i.e., #1 is the most-commonly reported etiology). Several etiologies were reported only once, resulting in a 'Top 7' list. Calculations include etiologic agents from outbreaks with multiple etiologies. Excludes outbreaks with known contamination at point of use (Deficiency 11A, etc.), unless non-POU outbreak deficiencies were also listed. Does not include historic legionellosis outbreaks reported in the 2007-2008 data summary due to missing drinking water system information.

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