More than 20 percent of the nation’s water treatment systems have violated key provisions of the Safe Drinking Water Act over the last five years, according to a New York Times analysis of federal data.
The water system in Ramsey, N.J., has illegal concentrations of arsenic and the solvent tetrachloroethylene, both linked to cancer.
That law requires communities to deliver safe tap water to local residents. But since 2004, the water provided to more than 49 million people has contained illegal concentrations of chemicals like arsenic or radioactive substances like uranium, as well as dangerous bacteria often found in sewage.
Regulators were informed of each of those violations as they occurred. But regulatory records show that fewer than 6 percent of the water systems that broke the law were ever fined or punished by state or federal officials, including those at the Environmental Protection Agency, which has ultimate responsibility for enforcing standards.
Studies indicate that drinking water contaminants are linked to millions of instances of illness within the United States each year.
In some instances, drinking water violations were one-time events, and probably posed little risk. But for hundreds of other systems, illegal contamination persisted for years, records show.
On Tuesday, the Senate Environment and Public Works committee will question a high-ranking E.P.A. official about the agency’s enforcement of drinking-water safety laws. The E.P.A. is expected to announce a new policy for how it polices the nation’s 54,700 water systems.
“This administration has made it clear that clean water is a top priority,” said an E.P.A. spokeswoman, Adora Andy, in response to questions regarding the agency’s drinking water enforcement. The E.P.A. administrator, Lisa P. Jackson, this year announced a wide-ranging overhaul of enforcement of the Clean Water Act, which regulates pollution into waterways.
“The previous eight years provide a perfect example of what happens when political leadership fails to act to protect our health and the environment,” Ms. Andy added.
Water pollution has become a growing concern for some lawmakers as government oversight of polluters has waned. Senator Barbara Boxer, Democrat of California, in 2007 asked the E.P.A. for data on Americans’ exposure to some contaminants in drinking water.
The New York Times has compiled and analyzed millions of records from water systems and regulators around the nation, as part of a series of articles about worsening pollution in American waters, and regulators’ response.
An analysis of E.P.A. data shows that Safe Drinking Water Act violations have occurred in parts of every state. In the prosperous town of Ramsey, N.J., for instance, drinking water tests since 2004 have detected illegal concentrations of arsenic, a carcinogen, and the dry cleaning solvent tetrachloroethylene, which has also been linked to cancer.