Unknown to most Americans, a surprising number of U.S. cities have drinking water with unhealthy levels of chemicals and contaminants. In fact, some organizations and state environmental agencies that collect and analyze water data say the level of chemicals in some Americans' drinking water not only exceeds recommended health guideline but the pollutants even exceed the limits set by the U.S. Environmental Protection Agency (EPA), the national legal authority in these matters.
The website 24/7 Wall St. examined the quality of water supplies in most major America cities, using data collected from multiple sources for five years (ending in 2009) by Environmental Working Group (EWG), based in Washington, D.C. The fact that the data covered a half-decade is important because it shows that the presence of certain chemicals is persistent.
Cities in Kansas, Louisiana, Mississippi, Tennessee and Georgia provided insufficient data to be included in EWG's database. Some other major cities outside of these states also failed to submit information, including Detroit, Salt Lake City and Washington, D.C.
Test results from EWG's national database covered "a total of 316 contaminants in water supplied to 256 million Americans in 48,000 communities in 45 states." According to the data, among the contaminants were 202 chemicals that aren't subject to any government regulation or safety standards for drinking water.
Based on the EWG's methodology, 24/7 Wall St. came up with its 10 worst cities list. These cities' water quality rank is based on three metrics, in order of increasing importance:
The percentage of chemicals found based on the number that were tested for
The total number of contaminants found
The most dangerous average level of a single pollutant.
Here's that list, in descending order, with the city's water utility in parenthesis:
10. Jacksonville, Fla. (JEA)
Located on the northeast coast of Florida, Jacksonville is the state's largest city. According to EWG, 23 different toxic chemicals were found in Jacksonville's water supply. The chemicals most frequently discovered in high volumes were trihalomethanes, which consist of four different cleaning byproducts -- one of which is chloroform. Many trihalomethanes are believed to be carcinogenic. Over the five-year testing period, unsafe levels of trihalomethanes were detected during each of the 32 months of testing, and levels deemed illegal by the EPA were detected in 12 of those months. During at least one testing period, trihalomethane levels were measured at nearly twice the EPA legal limit. Chemicals like arsenic and lead were also detected at levels exceeding health guidelines.
For the rest of the story: http://www.dailyfinance.com/2011/01/31/ten-american-cities-with-worst-drinking-water/