What is sewage sludge and when does it become “biosolids”?
Sewage sludge is the name for the solid, semisolid, or liquid materials removed during the treatment of domestic sewage in a treatment facility. Sewage sludge includes, but is not limited to, solids removed during primary, secondary, or advanced wastewater treatment, scum, domestic septage, portable toilet pumpings, Type III marine sanitation device pumpings, and sewage sludge products. When properly treated and processed, sewage sludge becomes “biosolids” which can be safely recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth.
