Indicator Report - Drinking Water: Nitrates
Why Is This Important?People drink and use water every day. The majority of Americans are provided with high quality drinking water. About 90% of people in the U.S. (262 million in 2006) get their water from a community water system versus a smaller water supply such as a household well. The U.S. Environmental Protection Agency sets regulations for treating and monitoring drinking water delivered by community water systems. Currently, there are water quality standards and monitoring requirements for over 90 contaminants. Drinking water protection programs play a critical role in ensuring high quality drinking water and in protecting the public's health.
Because people drink and use water every day, contaminants in drinking water have the potential to affect many people. The number of people served by a community water system varies from at least 25 people to hundreds of thousands. Community water systems in the U.S. provide among the highest quality drinking water in the world. However, some contaminants are present at low levels, and it is still possible that drinking water can become contaminated at higher levels. If a person is exposed to a high enough level of a contaminant, they may become ill. Effects can be by the duration (time) of the exposure. Short-term or long-term effects depend on the specific contaminant, the level of contaminant in the water, and the person's individual susceptibility. As additional information is obtained about how specific contaminants affect public health, standards may change in order to better protect public health.
Nitrate and nitrite are nitrogen-oxygen molecules which can combine with various organic and inorganic compounds. Nitrate is the form commonly found in water, often in areas where nitrogen-based fertilizers are used. Short-term health effects from drinking water with nitrate are most harmful to infants under six months of age. This can cause serious illness and sometimes death in this vulnerable population. Long-term exposures to nitrates in the general population may be associated with adverse reproductive problems and some cancers, primarily stomach. Currently nitrate levels are not supposed to exceed 10 milligrams of nitrates per liter of water in order to prevent any nitrate related adverse health effects.
Quarterly Number of People Served by Community Water Systems (CWS) by Mean Nitrate Concentrations Not Reported (1999-2009)
DefinitionA community water system is a public water system which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.
How We Calculated the Rates
Page Content Updated On 03/13/2012, Published on 03/19/2012