Understand Biosolids


Fertilizer and Fuel

Biosolids are the organic residuals generated during the treatment of sewage sludge. Appropriate management of these biosolids is critical to protection of the environment and public health. This industry engages myriad stakeholders — including municipal residents, commercial sewer users, agricultural interests, and environmental groups. At a cost of more than $2 billion dollars annually and with population growth continuing to expand wastewater volume, effective biosolids management is a daunting challenge for communities.

While the proper treatment and disposal of sludge is a public necessity for communities, the advancement of technologies also provides for opportunities. These include beneficial uses of biosolids as a fertilizer to increase crop productivity and, even more promising, the use of biosolids as a solid fuel and renewable energy feedstock.

Today, wastewater is routinely treated to destroy naturally occurring but sometimes harmful organisms. The process of separating the solids from the water produces a relatively dry, soil-like product called “cake,” which can be recycled back into the earth. In NEFCO facilities, this cake is exposed to high temperatures killing 95 percent of the pathogens present and substantially reducing odors. Water is removed from the biosolids, producing a high-quality, Class A pellet which can be used as a high-end fertilizer for agriculture. Using biosolids fertilizer pellets through land application safely enhances the soil with rich organic product that conditions it and increases plant growth.