Gov. Tony Evers said Wednesday his administration is calling for new regulations to protect drinking water in rural Wisconsin by limiting excessive spreading of a key chemical found in manure and fertilizer.

The aim is to drive down nitrate levels in groundwater and drinking water in targeted areas especially vulnerable to contamination.

High nitrate levels have been associated with blue baby syndrome, colorectal cancer, thyroid disease and some birth defects affecting the central nervous system.

Nitrates are one of the most common sources of well contamination in the state. According to the state Department of Health Services, 10% of private wells in Wisconsin have high levels of nitrate.

But in some regions, including southwestern and central Wisconsin, reports of well contamination are far higher.

In the central sands region that includes Stevens Point and neighboring communities, Evers said that 30% of private wells are estimated to exceed the state’s health standard.

RELATED:Study shows widespread well contamination in southwestern Wisconsin

In southwestern Wisconsin, tests involving 840 wells in November 2018 and in April showed excessive nitrate contamination that ranged from 12% in Grant County to 27% in Lafayette County. The work was conducted by the Wisconsin Geological and Natural History Survey and the U.S. Agricultural Research Service.

“Obviously we need to do better,” Evers said during a news conference in Watertown in Jefferson County.

Wednesday’s announcement comes as the Democratic governor declared 2019 “the year of clean drinking water,” underscoring problems ranging from polluted wells to lead contamination in municipal drinking water systems Evers seeks to address.

But his proposal to tackle nitrates could face roadblocks.

Lawmakers rejected an array of Evers’ clean water budget initiatives this summer.

His plans for nitrates will also require approval of the GOP-controlled Legislature, and must go through a rulemaking process that takes about 30 months.

Cleaning up wells by targeting farmers could also face resistance from agricultural groups, especially if farmers are not provided financial assistance.

Karen Gefvert, executive director of governmental relations for the Wisconsin Farm Bureau Federation, said her group wants to see more details. But she noted it is coming at a "time when agriculture is seeing the lowest of low commodity prices and we have farms going out of business at record rates."

Evers' proposal, she said, should not mean a "huge additional burden" on farmers.

Republicans, however, are also taking up water issues this year.

Assembly Speaker Robin Vos created a water quality task force in February and has been holding hearings around the state.

Clean Wisconsin, a major environmental group, applauded Evers’ proposal.

“This announcement shows that Gov. Evers is serious about cleaning up and protecting drinking water in Wisconsin,” said Scott Laeser, director of water programs.

“The new standards being proposed will offer hope to thousands of Wisconsin residents with nitrate pollution in their private wells.”

Evers is calling for targeted performance standards in areas with high nitrate levels that farmers would have to follow.

Brian M. Weigel of the state Department of Natural Resources said his agency will look for the most vulnerable areas, and with the help of the Department of Agriculture, Trade and Consumer Protection, will identify agricultural practices to limit nitrate contamination.

In some cases, he said, farmers might be required to receive subsidies from the state to pay for their efforts.

Under the administration of Republican Gov. Scott Walker, Wisconsin tailored performance standards for 15 counties — aimed especially at the dairy cattle-intensive northeast — to toughen standards for manure spreading.

The target of these standards is bacteria polluting wells.