LA CROSSE, Wis. — Officials in Wisconsin are considering how to respond to growing concerns over nitrate contamination in private wells.

A La Crosse County task force delegated to find new policies to address contamination issues recently presented their findings, Wisconsin Public Radio reported . The group suggested creating a new system to alert residents of contamination risks and increased access to municipal water systems.

The county has between 7,000 and 9,000 private wells, according to Carol Drury, the environmental health and laboratory manager at the La Crosse County Health Department.

The department warned 2,000 households last spring that their private wells could be contaminated with high nitrate levels.

"We tested 540 wells during that time just from this particular area, the town of Holland and the town of Onalaska, and 30 percent of those tested at levels about the recommended levels of nitrates," Drury said.

The county's findings are high, said Mark Borchardt, a research microbiologist for the U.S. Department of Agriculture.

"The national average across the U.S. is between 4 and 5 percent. In Kewaunee County, on a countywide basis, the number of private wells that exceed the 10 parts per million limit was 7 percent," he said.

High nitrate levels have been linked to adverse health effects, Borchardt said.

"It looks like the evidence is pointing toward high nitrate levels being associated with colorectal cancer, central nervous system birth defects and thyroid disease. So, it's not something to be taken lightly," he said.

Drury said preventing pollution is a long-term goal and that the department is committed to educating the public.

"That's going to take our local government working together and trying to come up with recommendations," Drury said. "Those are all processes that we know take time. So in the short term, we want to do what we can."