When the Hampton Roads Sanitation District ran short of storage space for biosolids, it had a choice: Add capacity for Class B biosolids or produce Class A material requiring less space.
The district went with Class A, and now the Atlantic Treatment Plant in Virginia Beach, Virginia, uses a high-temperature, high-pressure thermal hydrolysis process. The result is a drier, easily stored and more marketable product.
“We could just build another shed,” says Christopher Wilson, chief of process engineering and research. “Or we could do a process to make a better aesthetic cake and create opportunities for other beneficial-use outlets.” The Class A product is
