Biosolids are created through the wastewater treatment process. Both the Northeast and Theresa Street Water Resource Recovery facilities have the capabilities to utilize recovered liquid biosolids for beneficial use and turn the product into a dry, nutrient-rich matter that is used as a soil-like fertilizer on crops.

The Process: Wet to Dry

1 Feed & Mix

Liquid 2-3% solids are fed into a centrifuge. A polymer coagulant (thickening agent) is added.

2 Spin, Spin, Spin

The centrifuge spins like a washing machine in a spin cycle. The high speed rotation separates the solids and liquid materials.

3 Scrape & Separate

The scroll conveyor inside the bowl scrapes the solids off the inner bowl wall. The solids are moved in the direction of the centrifuge's solids discharge area.

4 Dry & Ready For Use

The longer the solids spin, the drier the solids become. The separated solids, now at more than 20% solid, are conveyed out to trucks for distribution to be spread on ag land as a substitute for fertilizer.

Biosolids: A Win-Win-Win

This soil-like, nutrient-rich matter can be put on crops year-round instead of just during the growing season.

Biosolids offer agriculture producers a fertilizer filled with healthy nutrients that is more environmentally friendly than synthetic fertilizers.

This project gives the City another way to reuse resources recovered from the community’s wastewater.

For more information to purchase the biosolids, agriculture producers and landowners can contact David Smith, Biosolids Coordinator at 402-441-6378 or