Wyoming's water is not currently tested for the presence of pharmaceuticals, but health and city officials say they are not too concerned about drugs being found in Wyoming water.

While other cities across the country are finding tiny concentrations of drugs in their drinking water, Casper is not at as much risk for contamination, said David Hill, public utilities manager for the city.

His counterpart in Cheyenne agrees.

Hill said Casper is close to its water source and the vast majority of the water comes from snow.

Clint Bassett, water conservation specialist for the city of Cheyenne, said most of the water in Cheyenne comes directly from the snow that falls on the Snowy and Laramie ranges.

"Since we are the first to use it, there is very little opportunity for drugs to get in it," Bassett said.

Most of the water in Wyoming is not recycled like it is in bigger cities, said Timothy Ryan, environmental public health section chief for the Wyoming Department of Health.

When a person flushes a toilet in Chicago or New York City, the water goes to a plant for cleaning and then is recycled back out, Ryan said.

"Here, it's not going toilet to tap," Ryan said. "It's going from snow to tap."

An investigation by The Associated Press found a vast array of pharmaceuticals - including antibiotics, anti-covulsants, mood stabilizers and sex hormones - in the drinking water supplies of at least 41 million Americans.

Even though the concentrations of the drugs in the water are small, the reports are raising the concerns voiced by some scientists across the country.

Hill said there needs to be more research done on how these minute doses affect humans.

"Here we have been following the trend for the past couple of years to see where it is headed," Hill said. "Most experts don't see a big concern, but it still needs to be studied."

Ryan said Wyoming's small population also has the potential to decrease the amount of pharmaceuticals found in the state's drinking water. However, it depends on the behaviors of people, and specifically in Wyoming, how many people are dumping their unused medications down the toilet.

Ryan said no one knows how widespread the practice is, but Patti Nelson, a staff pharmacist at the Wyoming Medical Center, said she knows several people who have done this.

Testing for drugs in the water doesn't happen in Casper because it is very expensive and there isn't a mandate to do it, Hill said.

Some cities are now testing for pharmaceuticals in water, while officials in Idaho and Arizona are studying the effects it has on the public, Ryan said.

"This really isn't news," Ryan said. "Scientists have known this and been studying it on animals and fish for a while. My gut instinct is it can't be really good on us."

Contact health reporter Allison Rupp at (307) 266-0534 or allison.rupp@trib.com.