The Wisconsin Department of Natural Resources is proposing adding 192 waterways to a list of those that don't meet water quality standards.
The Milwaukee Journal Sentinel reports most of the newly proposed additions have excessive levels of phosphorus. But other pollutants including bacteria, salt and industrial pollutants, are also factors.
Phosphorus is a nutrient in fertilizer, and comes from yards, manure and waste water treatment plants. It spurs algae and weed growth.
There are already more than 700 waters listed as impaired in Wisconsin, including many sections of the Milwaukee, Menomonee and Kinnickinnic rivers.
DNR officials say about 75 percent of the waters it monitors have shown trends of improving over the long term.