April 2008

U.S. Water News Online

PHOENIX — The city of Phoenix will begin testing its drinking water supply for trace amounts of pharmaceuticals in the wake of an investigation by The Associated Press that found contamination in many of the nation's major cities.

City officials originally said they would wait for the federal Environmental Protection Agency to develop standards for testing for prescription and over-the-counter drugs in water supplies.

But Mayor Phil Gordon told The Arizona Republic in a story posted on the paper's Web site that the city will go ahead immediately.

"Phoenix will be testing its water for pharmaceuticals, and we're not waiting for the EPA or anyone else to proceed," Gordon said. "We're doing it. Clean water is important. Healthy water is important. The health of our residents is important."

The months-long AP investigation found 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 residues have been found in Lake Mead, a source of drinking water sent to Phoenix and Tucson through the Central Arizona Project canal. Three medications, including an antibiotic, were found in drinking water supplied to Tucson. And researchers at Arizona State University also have found evidence of chemicals called endocrine disruptors in the second major source of Phoenix water, the Salt River Project.

"Our water is safe and healthy," Gordon said. "But given the AP's recent story on pharmaceutical traces being found in Lake Mead and in some national wastewater samples, we want to reassure the public, science in hand, that our drinking water is healthy."

City water department spokesman Ken Kroski said he could not say if the city's current water-cleaning technology effectively blocks dangerous pharmaceuticals. He said the department "is developing a testing protocol to establish baseline data to include in national research."

Phoenix is participating in two studies looking into the dangers, one through the WateReuse Foundation and the other through the American Water Works Association.

The drug concentrations found in the AP investigation were tiny, measured in quantities of parts per billion or trillion and far below the levels of a medical dose. Utilities insist their water is safe.

But the presence of so many prescription drugs — and over-the-counter medicines like acetaminophen and ibuprofen — in so much of the drinking water supply is heightening worries among scientists of long-term consequences to human health.

The drug residues get into the water supply from people taking the medication. Their bodies absorb some of it, but the rest passes through and is flushed down the toilet. The wastewater is treated before it is discharged into reservoirs, rivers or lakes.

Water for city use is cleansed again at drinking water treatment plants, but most treatments do not remove all drug residue.