What goes down your toilet can end up on farm fields across the United States.
Biosolids, or sewage sludge, are the solid byproducts of the wastewater treatment process. Rich in nutrients, they can be used as fertilizer on agricultural fields or compost on lawns.
But the process for producing these materials can vary greatly, and some unwanted things can end up in those biosolids. A recent study released by the U.S. Environmental Protec