& Biosolids
Biosolids
Resources
Biosolids are the nutrient-rich organic product of wastewater treatment. Biosolids contain essential plant nutrients and organic matter and can be recycled as a fertilizer and soil conditioner.
Wastewater treatment processes separate clean water from the solids. Wastewater solids, undergo further processing to create a material called biosolids. Biosolids can be used as a fertilizer and soil conditioner, disposed of in a landfill, or incinerated.
Using biosolids as a fertilizer is common practice in Minnesota and throughout the United States. Spreading biosolids onto the soil surface or incorporating or injecting them into the soil as a fertilizer is called land application. Land application is regulated by federal and state laws.
Biosolids land application recycles valuable nutrients and organic material back into the soil, improves soil fertility, increases crop yields, reduces the need for commercial fertilizers, and conserves space in landfills.
WLSSD annually produces over 30,000 tons of biosolids, called Field Green®,
and operates a year-round land application program. Field Green® is spread on
farm fields to produce feed crops and hay mulch and on taconite tailings basins to help establish
vegetative cover.