Arlington's drinking water tested positive for trace concentrations of the anti-anxiety medication meprobamate, city officials revealed Monday in response to public-records requests from the Star-Telegram> and others.
Arlington Mayor Robert Cluck said a few months ago that concentrations of one pharmaceutical had been found in treated drinking water, but he declined to name it, saying the information could prompt a terrorist to release more of the drug, harming residents.
However, the Texas attorney general's office said that concern wasn't well-founded.
Cluck, who is also a physician, said Monday that he used to prescribe the drug for anxiety but isn't sure whether it is still widely prescribed now. He said people shouldn't be afraid to drink Arlington's water.
"Tap water is all I drink," he said. "I never drink bottled water."
In water samples taken in October 2006, concentrations of the drug measured around 1 part per trillion, far below the levels of a medical dose. Water department officials say their drinking water meets the highest standard of quality.
Cluck said that only recently has the technology been available to detect such a small amount of the drug.
"If we had measured this three years ago, we wouldn't have picked it up," he said Monday. "It's not harmful."
The Associated Press reported in March that trace concentrations of pharmaceuticals have been detected in drinking water systems for 24 major U.S. metropolitan areas, affecting 41 million Americans.
As part of that series, the AP contacted Arlington officials and learned that water there had been tested. Arlington was the only place in the United States included in the AP PharmaWater series that declined to release its test results.
Cluck had directed local officials in 2006 to conduct tests after hearing that traces of Prozac had been found in water elsewhere in Texas. The tests are not required under federal or state regulations.
After the AP's story was distributed, Arlington officials provided a few more details: trace concentrations of five pharmaceuticals — one antibiotic, two anti-seizure medications, one pain reliever and oneminor tranquilizer — had been detected in the city's untreated source water.
The city also named the five: sulfamethoxazole, dilantin, carbamazepine, naproxen and meprobamate. But it declined at that time to identify which one had also been detected in treated drinking water.
Staff writer Sally Claunch contributed to this report.