MADISON, Wis. -- The Department of Natural resources is proposing tighter rules to better regulate the millions of gallons of manure produced by large livestock operations.

A plan that would prevent factory farms from dumping manure on frozen fields goes before a Legislative committee Thursday.

The plan also bans farmers from spreading solid manure during the months of February and March.

The DNR said the rules are needed because manure dumped on frozen land runs off and contaminates wells and rivers. The rules would apply to farms with more than 1,000 animals, or roughly 150 operations in Wisconsin.

The rules follow a WISC-TV investigation last year on the serious conflicts between what some call "factory farms" and the neighbors who live near them.

Some of the changes for large livestock operations would include having a minimum six months worth of storage for manure, and banning the spreading of liquid manure on frozen soil or now-covered ground unless it's immediately worked into the soil.

Some big dairy groups in Wisconsin said the DNR is going overboard and beyond what the federal Environmental Protection Agency has suggested.

But environmental groups said more needs to be done to protect the health of not just lakes, rivers and fish, but rural residents.

The Steinke family, which lives in the country in Dodge County, said it had its private well contaminated by manure.

"I was gagging and at that exact moment my daughter said, 'Why are you crying, mommy?' And I told her I wasn't crying -- it was manure," said Gina Steinke.

In the winter of 2005, some of the fields by the Steinkes' rural home turned into lakes of manure as a large diary operation nearby spread waste from its cows on the frozen ground.

State officials said the manure contaminated the aquifer and three private wells, including the Steinkes', turning their drinking water brown and dangerous.

Tests showed high levels of bacteria -- including E. coli, which is unsafe at any level.

"I was worried. I mean literally worried sick. I didn't know how long -- one of my first thoughts was, 'How long has it been in there, before it started to smell?" Steinke said.

The 3,700-animal operation recently settled with the state and last month reimbursed the Steinkes and two others for the new wells they had to put in.

But the Steinkes said their nightmare could have been avoided if manure hadn't been spread on frozen fields.

"No one should have to go through what we went through," Steinke said.

But some farmers said the proposed rules go too far and are too complicated.

"We got to become meteorologists ... in the whole process," said Richard Gorder, vice president of the Wisconsin Farm Bureau Federation.

Officials with statewide agricultural business groups said they have to predict the weather under the rules and they make manure management more confusing.

"All we're asking is for consistency between agencies so farmers know exactly what they have to deal with," Groper said.

Ag groups said the DNR's rule revision goes beyond what the federal EPA wants for so-called concentrated animal feeding operations, or CAFO -- those with over 700 cows.

The groups also said the rules are stricter than in other states, but environmentalists and others contend the requirements are in line with or less strict than those of other Midwest states.