What are common methods of sludge disposal?

• A. Class A: application by public in parks, gardens, and golf courses
• B. Class B: land disposal of industrial solids in landfills only
• C. Class B: disposal by incineration
• D. Class A: disposal by incineration

Answer: (A)

Class A biosolids are treated to meet very low pathogen levels, which allows them to be applied directly to public land surfaces. That means safe, common reuse on places where people go, like parks, gardens, and golf courses, providing a nutrient-rich soil amendment while disposing of sludge in a beneficial way. The other options mix up the classifications and disposal methods: Class B isn’t defined as disposal by incineration, and it involves a lower level of pathogen reduction with restrictions on where and when land application can occur. Incineration is a treatment option in some cases, but it isn’t the typical or defining method tied to Class A biosolids. Likewise, saying disposal is limited to land disposal of industrial solids in landfills doesn’t reflect how sludge or biosolids are managed under regulations, which include land application, landfilling, or incineration depending on treatment levels and regulatory requirements.