Two veteran U.S. senators said Monday they plan to hold hearings in response to an Associated Press investigation into the presence of trace amounts of pharmaceuticals in the drinking water supplies of at least 41 million Americans.

Also, U.S. Rep. Allyson Schwartz, D-Pa., has asked the EPA to establish a national task force to investigate the issue and make recommendations to Congress on any legislative actions needed.

Sen. Barbara Boxer, who heads the Senate Environment and Public Works Committee, and Sen. Frank Lautenberg, chairman of the Transportation, Safety, Infrastructure Security and Water Quality Subcommittee, said the oversight hearings likely would be in April.

Boxer, D-Calif., said she was “alarmed at the news” that pharmaceuticals are turning up in the nation’s drinking water, while Lautenberg, a New Jersey Democrat who said he was “deeply concerned” by the AP findings, both represent states where pharmaceuticals had been detected in drinking water supplies but not disclosed to the public.

“I call on the EPA to take whatever steps are necessary to keep our communities safe,” said Boxer in a statement.