Public water system
||The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. (November 2008)|
The US Safe Drinking Water Act and derivative legislation define public water system as an entity that provides "water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year."
Some US states (e.g. New York) have varying definitions.
Of the approximately 155,693 public water systems in the United States, 52,110 (33.5%) are community systems and 103,583 (66.5%) are noncommunity systems, including 84,744 transient systems and 18,839 nontransient systems.
According to the EPA, over 286 million Americans get their tap water from a community water system.8% of U.S. community water systems provide water to 82% of the U.S. population through large municipal water systems.
Additional US Public Water System Categorization
The United States Environmental Protection Agency (EPA) has defined three types of public water systems:
- Community Water System (CWS): A public water system that supplies water to the same population year-round.
- Non-Transient Non-Community Water System (NTNCWS): A public water system that regularly supplies water to at least 25 of the same people at least six months per year, but not year-round. Some examples are schools, factories, office buildings, and hospitals which have their own water systems.
- Transient Non-Community Water System (TNCWS): A public water system that provides water in a place such as a gas station or campground where people do not remain for long periods of time.
The EPA also classifies water systems according to the number of people they serve:
- Very Small water systems serve 25-500 people
- Small water systems serve 501-3,300 people
- Medium water systems serve 3,301-10,000 people
- Large water systems serve 10,001-100,000 people
- Very Large water systems serve 100,001+ people
Water systems may be categorized by their source of water:
- Groundwater, generally from wells
- Surface water and groundwater "under the influence" of surface water
- Purchase of water from another Public Water System
The term "public" in "public water system" refers to the people drinking the water, not to the ownership of the system.
Sources of drinking water are subject to contamination and require appropriate treatment to remove disease-causing contaminants. Contamination of drinking water supplies can occur in the source water as well as in the distribution system after water treatment has already occurred. There are many sources of water contamination, including naturally occurring chemicals and minerals (for example, arsenic, radon, uranium), local land use practices (fertilizers, pesticides, concentrated feeding operations), manufacturing processes, and sewer overflows or wastewater releases.
The presence of contaminants in water can lead to adverse health effects, including gastrointestinal illness, reproductive problems, and neurological disorders. Infants, young children, pregnant women, the elderly, and people whose immune systems are compromised because of AIDS, chemotherapy, or transplant medications, may be especially susceptible to illness from some contaminants.
To see a list of The Top 10 Causes of Waterborne Outbreaks in Public Water Systems go to CDC's Drinking Water Site.
- Province of Manitoba. "The Drinking Water Safety Act". Winnipeg, MB. Retrieved 2009-01-05.
- Province of Nova Scotia. "Water and Wastewater Facilities and Public Drinking Water Supplies Regulations". Halifax, NS. Retrieved 2009-01-05.
- U.S. Environmental Protection Agency (EPA). "EPA Public Drinking Water Systems". Washington, DC. Retrieved 2008-11-22.