Regulators can't properly decide whether to impose limits on residues of prescription drugs in U.S. drinking water.By JUSTIN PRITCHARD, Associated Press

LOS ANGELES (AP) — Federal regulators who are supposed to decide whether to impose limits on prescription drugs in U.S. drinking water still aren't even sure which pharmaceuticals pose human health risks at the low concentrations scientists are finding, government investigators say in a new report.

What began several years ago as a coordinated effort among federal agencies to analyze what — if anything — should be done about hormones, antibiotics, painkillers and other drugs in tap water has fizzled, according to a report released Thursday by the Government Accountability Office.

The solution proposed by GAO investigators: Another federal "workgroup" to tackle the issue systematically.

The lack of coordination among regulators persists three years after an Associated Press investigation revealed that traces of pharmaceuticals were passing through treatment plants and into drinking water supplies nationwide.

The main source of the contamination is medicine that people take, but that their bodies don't fully absorb. Some of the active ingredients are flushed when people use the toilet, beginning a journey to sewage plants, into waterways that are drinking water sources, and — after further treatment to make it potable — back to the kitchen sink.

Representatives of water utilities and pharmaceutical manufacturers say that the low concentrations pose no human health risk — that a person would need to drink thousands of glasses of water to get a typical therapeutic dose. Research cited in AP's original 2008 investigation suggested cause for concern: Even very small amounts of unwanted drugs could do cumulative harm to people who regularly drink water, in part because they may combine with other pharmaceuticals to unforeseen effect, according to researchers.

In the new GAO report, investigators focused on the U.S. Environmental Protection Agency, which is in charge of national water policy.

Two years ago, the EPA announced that it would consider setting limits for pharmaceuticals in drinking water, publishing a list of nine sex hormones, one antibiotic and two other chemicals that remain candidates for regulation. Making the candidate list doesn't mean a chemical will be regulated — that's the analysis EPA officials have to complete, and they have said they intend to make preliminary decisions on some of the 12 contaminants next year.

Just how that will be done was one source of concern to authors of the GAO report, who cited a lack of data on water quality and human health effects.

"EPA is collaborating with the Food and Drug Administration and U.S. Geological Survey on research to help obtain such data but these efforts are largely informal," the authors wrote. "EPA officials said there is no formal mechanism, such as a long-term strategy or formal agreement, to manage and sustain these collaborative efforts."

An EPA spokeswoman did not answer questions from the AP. In a letter responding to the report before it was made public, EPA's acting administrator for water, Nancy K. Stoner, wrote that the agency agreed with the recommendation of a more coordinated effort across agencies, with the caveat that its level of involvement would depend on available resources.

That would not be the first workgroup on the subject.

An effort known as Pharmaceuticals in the Environment, which involved scientists at eight federal agencies, culminated in 2009 with a draft report that was never publicly released. Comments included in the GAO report from several participating agencies show that bickering over what that report should include led to its death.


The AP National Investigative Team can be reached at

Pritchard can be reached at