A team of investigators has discovered traces of two pharmaceuticals in the treated wastewater Gwinnett County discharges into the Chattahoochee River upstream from the drinking water intakes for Atlanta and Cobb County.

The lead investigator of the ongoing study declined to identify the two drugs but said the amounts discovered were at levels below 40 parts per trillion, much smaller than medical doses.

Philip Singer, of the University of North Carolina at Chapel Hill, said it would be "irresponsible" for him to name the drugs just a few months into his yearlong study, which began in December. A full report should be done by March or April of next year, Singer said.

"You need to kind of look at these things not just on a single sample but on repeated samples to really understand whether or not they represent any kind of concern or not," said Singer, a professor in UNC's School of Public Health.

A top water department official with Gwinnett County, which ordered the $265,000 study, also declined to identify the contaminants.

"Finding the things one time —- I think we would rather not say what they are until we have some better information on that," said Neal Spivey, the county's water production director. "It is just one occurrence right now. We just don't have enough data to say confidently whether it is ... something to be concerned about or not."

Streams flowing into the river between Gwinnett's wastewater discharges and Cobb County-Marietta Water Authority and Atlanta Watershed Department's intakes serve to mix the water, diluting impurities, said Glenn Page, general manager of the Cobb utility.

The drugs could have gotten into the water by the simple act of people swallowing pills, Singer said. Bodies don't absorb all medication, so some of it goes down the toilet and into the sewage system. Also, some people throw unused drugs into toilets and sinks.

Singer's team is also testing near the county's drinking water intake on Lake Lanier. They are looking for traces of 16 pharmaceuticals and "personal care products," such as ibuprofen —- a common pain reliever —- and DEET, an insect repellent. So far, Singer said, the investigators have detected only caffeine, which is found in coffee, tea and soda and used in medicine as a nervous system stimulant. Spivey said he was wrong last week when he said Singer's team had found more than one chemical in the lake.

No contaminants were found in the county's drinking water, Singer said.

Spivey disclosed the study was under way on March 10, the same day newspapers nationwide published an Associated Press investigation that says a vast array of pharmaceuticals —- including antibiotics, anti-convulsants, mood stabilizers and sex hormones —-have been found in the drinking water supplies of at least 41 million Americans.

The AP report says the following pharmaceuticals were found in the Atlanta metro area, though it was not specific where they were found: sulfamethoxazole, which is used to treat infections of the urinary tract; diltiazem, used to treat hypertension, angina or heart failure; and acetaminophen, a pain reliever and fever reducer. The presence of these drugs in drinking water, according to the AP report, is heightening concerns among scientists about the long-term impacts on human health and the environment.

Jackie Joseph, president of the Lake Lanier Association, a lake protection group, said she is glad Gwinnett is testing for these contaminants.

The drugs found in Gwinnett's treated wastewater were detected at the county's F. Wayne Hill Water Resources Center in Buford. The county has received approval to begin discharging wastewater from that plant into Lake Lanier and could begin doing so as early as the middle of next year, Spivey said.

"It is a good idea [to do the testing] because many people have always been concerned about what is in the water," Joseph said. "It is a necessity."

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