An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.


In-Vessel Composting of Biosolids

Biosolids are primarily organic materials produced during wastewater treatment which may be put to beneficial use. Composting is the biological degradation of organic materials under controlled aerobic conditions. The process is used to stabilize wastewater solids prior to their use as a soil amendment or mulch in landscaping, horticulture, and agriculture. Stabilization of wastewater solids prior to their use serves to destroy pathogens (disease causing organisms), minimize odors, and reduce vector attraction potential.You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.