Sludge Fertilizer Program Spurs Concerns

Chris Peot shows biosolids, applied to a farm, in Mitchells, Va., Wednesday, June 6, 2007. No one can say exactly what is in sludge. It's a constantly changing brew of human, commercial, hospital and industrial wastes. The primary organic ingredient is human excrement, which proponents say makes sludge a useful fertilizer. Critics worry about the metals and pathogens that remain. (AP Photo/Manuel Balce Ceneta)