Like most cities in the United States, Durango does not test its drinking water for pharmaceutical byproducts, but local water meets all safe-drinking water standards.

Durango Public Works Director Jack Rogers said because the majority of the city's water supply is in the wilderness of the Florida River drainage, there is little chance the water is affected by human drug, makeup or hygiene products.

"Some of our water supply comes from the Animas, and we use it mostly during periods of high runoff, so that the dilution of the human waste from Silverton and Durango Mountain Resort that reaches our water supply is pretty significant," Rogers wrote in an e-mail.

Because of Durango's comparative isolation, and its elevation, the risk of its water supply being contaminated is less than that of Dallas or Cleveland.

"That does not mean that we are not concerned," Rogers said. "We would like to work on a source water protection program in the near future."

Otherwise, Durango's water meets all water standards, and the water department tests for metals and carcinogens in the water but not endocrine disruptors - the synthetic chemicals that, when absorbed into the body, either mimic or block hormones and disrupt the body's normal functions.

Consumers are considered the biggest contributors to the contamination from pharmaceuticals. We consume drugs, then excrete what our bodies don't absorb. Other times, we flush unused drugs down toilets. The Associated Press found that an estimated 250 million pounds of pharmaceuticals and contaminated packaging are thrown away each year by hospitals and long-term care facilities.

Researchers have found that even extremely diluted concentrations of drugs harm fish, frogs and other aquatic species. Also, researchers report that human cells fail to grow normally in the laboratory when exposed to trace concentrations of certain drugs.

Some scientists say they are increasingly concerned the consumption of combinations of many drugs, even in small amounts, could harm humans over the course of decades.

Utilities say the water is safe. Scientists, doctors and the EPA say there are no confirmed human risks associated with consuming minute concentrations of drugs. But those experts also agree that dangers cannot be ruled out, especially given the emerging research.

Concerns about the quality of water released from Durango's wastewater treatment plant led to the city moving the plant's discharge point in the Animas River downstream, below where water will be pumped into Lake Nighthorse.

The U.S. Bureau of Reclamation, which is building the Animas-La Plata Project, is requiring and paying for the relocation, which began in February.

A 2002 study conducted by the New Mexico Environmental Department found that the ambient waters in northern New Mexico contained no evidence of drug residues. The study did not test for lipid-regulating, cardiovascular or antibiotic drug residues. But trace amounts of estrogenic compounds of the kind that have been demonstrated to cause sexual disruption in wild fish were found.

Ron Rosen, project director of CH2M HILL OMI, the corporation contracted by the City of Farmington to handle its water and wastewater, said his department tests for all contaminants listed in the Safe Water Drinking Act and those required by the New Mexico Department of Health. The U.S. Centers for Disease Control and Prevention's National Poisoning Data System further requires the department to test for fecal coliform and E. coli.

But the city doesn't test for "emerging contaminants" such as endocrine disruptors, which could originate in Durango's toilet bowls.

Aquatic biologist Chester Anderson of Durango-based BUGS Consulting, said emerging contaminants are something to worry about, but with so much unknown and so many known contaminants still creating problems, effective detection might still be far off.

"Because this is so new, lab analyses are complex and expensive," he said. "They haven't developed a real easy way to test for these pollutants."

The Associated Press contributed to this report.