The terms biosolids and sewage sludge are often used interchangeably. When properly treated and processed, sewage sludge becomes biosolids; the nutrient-rich organic materials resulting from the treatment of domestic sewage in a wastewater treatment facility. Biosolids can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth. You will see the term sewage sludge used in the context of regulations, as EPA has established a protective regulatory framework to manage the use and disposal of sewage sludge. Effective sewage sludge and biosolids management options help ensure that useful materials are recycled on land and harmful materials are not released to water bodies.