Ron Seely

The state Department of Natural Resources has approved a permit that will allow the Rosendale Dairy, near Ripon in Fond du Lac County, to expand from 4,000 to 8,000 cows, which would make it the largest of the state’s so-called factory farms.

With 8,000 cows, the farm will produce more than 92 million gallons of manure a year, making it the state’s third largest producer of waste, behind Milwaukee and Madison, according to the DNR. Under the modified permit approved by the agency Friday, the farm will have to expand the acreage on which manure will be spread from 4,000 to 12,000 acres.

The DNR also required the farm to meet some requirements beyond standards in the law that govern the operation of such large-scale farms. For example, Rosendale Dairy will not be allowed to spread manure within 200 feet of private wells, even though the law calls only for a 100-foot buffer.