Part A: Sanitization and use of sewage sludge in soil Technical Note 2 - Legislation aspects

The use of sewage sludge in soil is a environmentally sustainable practice, compatible with the Brazilian Policy of Solid Wastes. Due to its content of organic compounds and nutrients, the sludge is beneficial to the physical, chemical and biological soil properties and to the development of plants. However, since it may contain chemical and microbiological pollutants, it has to be carefully used by following criteria and procedures concerning the protection of the environment and public health. In 2020, Brazil approved Resolution 498 of CONAMA for the definition of criteria and procedures for production and application of biosolids in soil. Besides its agricultural use, this Resolution covers other uses, such as the recuperation of degraded areas. For the use of sludge on land, it needs to be processed in a Sludge Management Unit licensed by a local environmental agency. Depending on the criteria in the Resolution, biosolids are classified under Classes A and B for their microbiological quality, and under Classes 1 and 2 for their chemical aspects.