WASHINGTON — The Environmental Protection Agency unveiled a new national strategy to enforce safe drinking water laws in small, rural communities on Tuesday, and pledged to redouble efforts to protect children from toxic water in schools.

The announcement came during a hearing in the Senate Committee on Environment and Public Works held to examine reports of widespread water contamination and unsafe levels of lead and other toxics flowing through the pipes at thousands of U.S. schools.

As part of the new approach, EPA officials said the agency would pay particular attention to chronic violators, and said in some cases they would ask small water systems to restructure or merge to improve their safety records.

The hearing followed an Associated Press investigation showing that roughly one in five schools with their own wells violated the Safe Drinking Water Act in the past decade, a problem that until now has gone largely unmonitored by the federal government.

Sen. Barbara Boxer, D-Calif., who chairs the committee, chided officials for the lack of specifics in their plan and pressed for more details.

"We know where the standards are being violated but it falls apart because there is no enforcement," Boxer said. "You need to take action to protect our kids."

EPA officials said the gist of their plan is to address underlying problems for entire drinking water systems rather than focusing on one contaminant at a time.

"Protecting children's health is a high priority," said Peter Silva, assistant administrator for water at the EPA. "To make any real difference, we know we must assist the small systems, because 96 percent of all health-based violations occur at systems serving less than 10,000 people."

Under federal law, schools with their own wells — which represent about 10 percent of the nation's schools and are often located in isolated, rural communities — are required to test their water and report any problems to the state. In turn, the state is supposed to send all violations to the federal government.

Larger, urban schools that get water from local utilities, however, are not required to test for toxics because the EPA regulates their water providers. That means there is no way to ensure detection of contaminants caused by schools' own plumbing. Lead often concentrates at higher levels in school pipes than in most homes, since they contain dozens of soldered joints where the metal can flake off.

EPA officials said they would begin targeting repeat violators of the nation's safe drinking water law in January, but Boxer said she needed more specifics about how all schools' water systems would be monitored for compliance.

Dozens of contaminants surfaced in drinking water at public and private schools in all 50 states, and at school districts in small towns and inner cities alike, according to EPA data analyzed by the AP.

"I'm not interested in round about help. What do I have to do to make sure that you can get in there and clean up that water?," Boxer said.

Boxer said state and local water agencies are the first line of defense to ensure that children have safe drinking water. However, the EPA is critically important in setting standards and in ensuring that state and local governments actually address problems with their systems.

Jeffrey Griffiths, a professor at Tufts University School of Medicine, said water providers should be held accountable for safety lapses. The federal government should in turn help keep water from getting contaminated in the first place, and help utilities adopt modern technology that will remove contaminants.

Sen. James Inhofe, R-Okla., said Congress can't expect small communities to prove safe drinking water if they don't have the money to upgrade their infrastructure.

Gene Whatley, executive director of the Oklahoma Rurual Water Association, said the cost of meeting a growing list of EPA regulations has made it harder for communities to overhaul their water systems. They spend money on unnecessary testing rather than on upgrading their infrastructure, he said.

Cynthia Giles, an assistant administrator for enforcement at EPA, said the agency will focus on regulating the most important violations, but did not elaborate on how that would apply to schools. She acknowledged that some smaller water systems have had historic problems complying with the law, and that the agency's main database of these violations contained errors.

"We share the frustration of trying to work with some of these smaller systems to get them into compliance," Giles said in an interview after the hearing.

Associated Press staff writer Garance Burke in Fresno, Calif. contributed to this report.