Do biosolids have an odor?
Because biosolids originate in sewage, they can have an odor, but typically any odor quickly dissipates in the atmosphere. Improperly managed programs can lead to odors, creating a public nuisance for local residents (See Guide to Field Storage of Biosolids.) If the biosolids have been properly treated at the wastewater treatment facility and responsibly managed during the production of compost and fertilizer and during application to farmland, odor usually does not present a problem. The siting, design and operation of biosolids facilities now routinely provide the necessary safeguards against the release of odorous compounds. In the production of fertilizer products from biosolids, advanced technology that provides for thermal destruction of odorous compounds in a fully enclosed facility is a proven solution for controlling odors. In composting, managers successfully control odors by maintaining aerobic conditions and directing process air through scrubbers and/or biofilters in an en
Fresh, damp biosolids can have an odor, usually described as “earthy” or “organic,” similar in some respects to bone meal or manure; people often describe a hint of “ammonia” to the odor as well. After being worked into the soil the odor typically dissipates within a short time. Composted soil amendments containing biosolids, like GroCo, have been further composted with sawdust, so have much less odor — usually quite similar to potting soil or any other organic mulch.
The short answer is yes. The long answer is that the degree depends on the treatment type and the method employed in the application. These odors can be reduced to levels not noticeable by the public if properly applied. A composted material such as that generated at the Oakland Wastewater Treatment Plant has only a faint odor to begin with and will not give off a noticeable odor once tilled in by the farmer. Our Division requires daily tillage in areas where farm application is in the vicinity of housing.
