Antibiotics, herbicides and sunscreen are among 22 contaminants researchers have found in Helena Valley wells.

A test of 38 Helena Valley wells from the North Hills to Montana City showed trace amounts from a range of pharmaceuticals and personal care products, according to sampling done by state and local water-quality experts. The study was the first of its kind in Montana.

Using data collected last year, all but three of the public and private wells tested also found the presence of antibiotics, bug spray, caffeine, ibuprofen, steroids -- and even lotion.

Meanwhile, Lewis and Clark County officials said they probably won't be able to build a proposed central Helena Valley sewer extension in one shot. The line was proposed to replace some aging wastewater systems.

The study's findings were contained in a report by Montana Department of Environmental Quality researchers Kathleen Miller and Josephy Meek.

The study authors couldn't be reached Friday afternoon, but City-County Health Department watershed expert Jim Wilbur said the report isn't cause for undue alarm. He said the contaminants were found at very low concentrations.

But the results demonstrate the humans impacts on the water they use, Wilbur said.

"These chemicals are pervasive in our society," Wilbur said. "What we flush down our septic systems...does not disappear. To us, it's confirmation that humans are having an impact on our groundwater."

The study was a cooperative effort of the DEQ, the City-County Health Department, and the Montana Bureau of Mines and Geology.

The Environmental Protection Agency now requires bacteria testing of public water supplies, which can indicate nitrates. Nitrate contamination is usually due to one of three sources: fertilizers, livestock and septic systems.

The report anticipates proposed federal rules regarding groundwater. And it comes during an ongoing public debate about an extension of city wastewater services.

County Administrator Ron Alles said Friday the county won't likely be able to build the proposed four-mile, $4 million extension to Sierra Road. But they can help existing neighborhoods hook up -- with city approval.

Developers of the 325-lot Aspen Trails Ranch subdivision north of the Helena Regional Airport are pursuing a city-approved extension. A county-approved Grasslands subdivision to the north may do the same, Alles said.

Some of the wells in the study were chosen randomly, while others were picked due to suspected contamination. The well locations were roughly concentrated north of East Helena, west of Helena, and the central and north Helena Valley areas, according to a map in the study.

"Every time someone gets in the shower and washes off sunscreen, it makes its way into the groundwater," said WQPD administrator Kathy Moore in a prepared statement. "When thousands of people are using sunscreen every day, and then washing it off into the groundwater, the impact adds up quickly."

Pharmaceuticals and personal care products have likely been in the groundwater for some time, Moore said, but the county previously didn't have the equipment to test for them.

The City-County Health Department recommended throwing old medications away in the garbage. The old medications can be put in a plastic pop contained with bleach or water to render them unuseable, she said.

For educational handouts about pharmaceuticals in groundwater, call 457-8926 or email Moore at kmoore@co.lewis-clark.mt.us

Reporter Jason Mohr can be reached at 447-4075 or jason.mohr@helenair.com.