Utah was among those states across the country that had more than one contaminant discovered in a sampling of water taken from private domestic wells, according to the U.S. Geological Survey.

Sampling done from 1991 to 2004 in multiple private wells in Utah showed concentrations of nitrate and arsenic at levels that demonstrate potential health concern, according to a report released Friday.

Problematic is that the fact that across the country 15 percent of the population relies on drinking water from private wells which are not regulated by the Federal Safe Drinking Water Act.

As a result, the agency said those 43 million people may be exposed to unhealthy levels of contaminants that pose public health risks.

In the survey, scientists sampled 2,100 private wells in 48 states. Many of the contaminants occur naturally because of geological factors and the materials that make up aquifers from which the water is drawn.

Nitrate was the most common inorganic contaminant found and it is generally derived from fertilizer applications and other agricultural uses. Water taken from Utah's wells tested for nitrate at concentrations greater than federal drinking water standards for public water supplies, a measurement that put Utah in company of just 4 percent of the wells sampled.

Utah's wells also landed in the category of 65 percent of the wells that tested for levels of radon that exceeded those same federal standards.

Not surprisingly, all of Utah's wells that were sampled tested at the extreme end of the scale in terms of water "hardness."

Although not a health concern, hard-water is a nuisance, the survey reported, and contributes to build up of mineral deposits in water systems.

The study stresses the need for private well owners to work with state and local government agencies on maintenance of wells, water quality, testing options and using in-home water treatment devices, the release said.