Science, Tech, Math Social Sciences Tap Water in 42 States Contaminated by Chemicals EWG Tap Water Probe Reveals 141 Unregulated Chemicals Flowing into U.S. Homes Share Flipboard Email Print Shilpa Harolikar/Moment Open/Getty Images Social Sciences Environment Pollution Climate Change Green Living Health Alternative Fuels Preservation & Conservation Psychology Sociology Archaeology Economics Ergonomics Maritime by Larry West Updated March 17, 2017 Public water supplies in 42 U.S. states are contaminated with 141 unregulated chemicals for which the U.S. Environmental Protection Agency has never established safety standards, according to an investigation by the Environmental Working Group (EWG).Tainted Tap Water Used by Millions of AmericansAnother 119 regulated chemicals—a total of 260 contaminants altogether—were found by the environmental group in a two-and-a-half-year analysis of more than 22 million tap water quality tests. The tests, which are required under the federal Safe Drinking Water Act, were conducted at nearly 40,000 utilities that supply water to 231 million people.Pollution Threatens Tap Water QualityAccording to a report by the EWG, the top 10 states with the most contaminants in their drinking water were California, Wisconsin, Arizona, Florida, North Carolina, Texas, New York, Nevada, Pennsylvania and Illinois—in that order. EWG said the biggest sources of contaminants were agriculture, industry and pollution from sprawl and urban runoff.Utilities Need More Enforceable Standards for Tap WaterEWG's analysis also found that almost all U.S. water utilities comply fully with enforceable health standards once they are developed. The problem, according to the environmental group, is the EPA's failure to establish enforceable health standards and monitoring requirements for many tap water contaminants. "Our analysis clearly demonstrates the need for greater protection of the nation's tap water supplies, and for increased health protections from a number of pollutants that are commonly found but currently unregulated." said Jane Houlihan, vice president for science at EWG, in a prepared statement. "Utilities routinely go beyond what is required to protect consumers from these contaminants, but they need more money for testing, and for protection of vital source waters." Additional Information:Read the Report: A National Assessment of Tap Water Quality National Tap Water Quality Database How Safe is Tap Water? Why is Chlorine Added to Tap Water? Does Fluoride in Tap Water Improve or Harm Your Health? What’s in Your Water? – Check the National Tap Water Testing database to learn the quality of your local tap water. Find a Contaminant – Check this list of contaminants, which have been found in tap water tests by water utilities and lack enforceable health standards. citecite this article Format mla apa chicago Your Citation West, Larry. "Tap Water in 42 States Contaminated by Chemicals." ThoughtCo, Dec. 10, 2014, thoughtco.com/chemical-contaminated-tap-water-in-us-1204205. West, Larry. (2014, December 10). Tap Water in 42 States Contaminated by Chemicals. Retrieved from https://www.thoughtco.com/chemical-contaminated-tap-water-in-us-1204205 West, Larry. "Tap Water in 42 States Contaminated by Chemicals." ThoughtCo. https://www.thoughtco.com/chemical-contaminated-tap-water-in-us-1204205 (accessed April 23, 2018). copy citation Continue Reading