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 by the Senate Environment and Public Works Committee 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, for instance, 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.