Two of the Atlanta region's biggest water suppliers say they don't know if there are drugs in the drinking water they serve the public because the federal government does not require such testing.

"It would be an additional cost, and no water utility out there has money lying around to do stuff they are not required to do," said Janet Ward, spokeswoman for the Atlanta Watershed Management Department, which serves drinking water to 1.2 million people in Atlanta, Sandy Springs and Fulton County.

Likewise, a water official in Cobb County said that utility, which serves 800,000 people, doesn't test because it doesn't have to. Their comments came the same day an Associated Press investigation was published in newspapers nationwide saying that a vast array of pharmaceuticals have been found in the drinking water supplies of at least 41 million Americans.

The AP report said the concentrations of these drugs are tiny, far below the levels of medical doses. Even so, the report says the presence of these drugs in drinking water is heightening concerns among scientists about the long-term impacts on human health and the environment.

Lake Lanier studied

Gwinnett County, meanwhile, is paying $300,000 for a study of Lake Lanier, the region's main source of drinking water. Preliminary findings from the University of North Carolina study show some pharmaceuticals and "personal care products" were in the lake in January but not in the county's treated drinking water, said Neal Spivey, the county's director of water production.

Spivey said he did not know which types of chemicals were found in the lake. The study, he said, is continuing and the county is not expected to get a preliminary report until May.

"I would not be alarmed based on what I know right now," Spivey said. "It is hard to base anything on results of one sample. But this is pretty much what I expected to find — very low concentrations — because Lanier doesn't get a whole lot of treated wastewater in there, which is where most of these things are coming from."

The county's investigation was prompted, Spivey said, by other studies across the country. He also mentioned the American Water Works Association was aware the AP was working on an article about the presence of drugs in the nation's drinking water supply.

AP reporters, according to the article, reviewed hundreds of scientific reports, analyzed federal drinking-water databases and visited environmental study sites and treatment plants. Among the AP's findings were:

• Testing in Philadelphia discovered 56 pharmaceuticals or byproducts in treated drinking water, including medicines for pain, infection, high cholesterol, asthma, epilepsy, mental illness and heart problems;

• Anti-epileptic and anti-anxiety medications were detected in a portion of the treated drinking water for 18.5 million people in Southern California;

• U.S. Geological Survey researchers analyzed a Passaic Valley Water Commission drinking water treatment plant, which serves 850,000 people in Northern New Jersey, and found a metabolized angina medicine and the mood-stabilizing carbamazepine in drinking water;

"This is obviously a national problem," said Sally Bethea, executive director of the Upper Chattahoochee Riverkeeper, a Georgia water protection organization. "The EPA needs to show leadership and require local governments to do some testing for pharmaceuticals and personal care products."

Benjamin H. Grumbles, assistant administrator for water at the U.S. Environmental Protection Agency, was not available for comment Monday, said an EPA spokeswoman. But Grumbles told the AP the presence of drugs in drinking water "is a growing concern and we're taking it very seriously."

The simple act of swallowing a pill could put drugs in the drinking water system. Bodies don't absorb all medication, so the rest can go down the toilet and into the sewage system. That wastewater is treated and released into rivers, lakes and reservoirs and then it is cleaned before it ends up in drinking water.

Atlanta water tainted

The conditions exist in the Atlanta area for drugs to get into the drinking water supply. Some communities discharge treated wastewater upstream from drinking water intakes on the Chattahoochee River for the Cobb County-Marietta and Atlanta utilities. But local utility managers say they use water-cleaning methods that can zap these contaminants.

"Gwinnett uses ozone as its disinfectant to kill the bugs and critters and things in the water," Spivey said. "Ozone happens to be very effective at removing pharmaceuticals and most of the personal care products."

A DeKalb County water department spokeswoman said she could not immediately respond to a request for comment Monday.

Some chemicals have managed to make it into the drinking water supply despite treatment processes. For example, a 1999 study by the U.S. Geological Survey and the U.S. Centers for Disease Control and Prevention found traces of caffeine, cotinine and acetaminophen, such as Tylenol, in treated drinking water in metro Atlanta. The study also found 16 pharmaceuticals in the region's treated wastewater and 10 in raw-water samples.

"The detection of antibiotics in raw drinking water," the report said, "is of particular concern because the presence of these chemicals in the environment may lead to the development of resistant bacterial strains, thus diminishing the therapeutic effectiveness of antibiotics."

Still, local utility managers said people should be measured in their reaction to the AP report.

"We are looking at a situation in many areas where the presence [of pharmaceuticals] is likely but the concentration is very unlikely to create any type of health concerns," said Glenn Page, general manager of the Cobb County-Marietta Water Authority.

The Associated Press contributed to this article.