MILWAUKEE – Mounting concern about chemical contaminants in sewage sludge, a waste product widely seen as recyclable and economically valuable, could turn into a costly liability and upend the finances of municipal wastewater utilities across the county.

The worry is particularly relevant in Milwaukee, Wisconsin’s largest city, which for 99 years has stripped its wastewater of liquid effluent, pathogens, heavy metals, and some chemicals to produce “biosolids” that it converts into a nitrogen-rich fertilizer. Trademarked as Milorganite – short for Milwaukee organic nitrogen – the turf grass fertilizer is bagged for commercial retail sale in home-and-garden centers in 49 states. Read more