DC Sludge Upgrade Could Produce Valuable Fertilizer; But Critics Wary
The nation's largest advanced sewage treatement plant, Blue Plains in Washington, DC, is spending $400 million to upgrade its sludge-processing to produce "Class A" fertilizer. Critics say the cooked sludge may be free of pathogens, but the real issue may be nutrients like nitrogen or phosphorus, heavy metals like cadmium or lead, and toxic chemicals like PCBs and perfluorochemicals.