ROCHELLE — The City of Rochelle Wastewater Treatment Plant produces a waste material called secondary sludge.  Since 1993, the sludge, which consists of 80 percent water and therefore is very heavy, has been transported to and disposed of in the city landfill. 

Over the past couple of years, Rochelle Municipal Utilities Water & Water Reclamation Superintendent Adam Lanning has been researching an alternative to dispose of the sludge: Using it as farm fertilizer. And so, the experiment began.

RMU crews rented a manure spreader to spread the wet sludge out on top of a concrete pad at the plant.

“We wanted to let the sun naturally dry out the sludge,” Lanning said.

The trial yielded biosolids of approximately 40 percent water and 60 percent solids, greatly reducing the volume of the sludge.  

To be used as farm fertilizer, the material had to meet state and federal land application standards. RMU was issued a permit earlier this year to land-apply the biosolids on farm fields.  

In November, the land application began. Approximately 600 tons of dried biosolids were used to fertilize 48 acres of local farmland. This nutrient-rich material added 165 pounds of plant-available nitrogen, 428 pounds of phosphorus and 88 pounds of potassium per acre.

In addition, the city added approximately 500,000 pounds of organic matter to the soil which is vital to create a productive soil for growing crops. 

The benefits of land application include reducing the material disposed of in the landfill, reducing costs to the utility and ultimately our customers, returning a rich organic material back to the soil and providing a fertilizer for the local farmland.  

The process of utilizing the sun to break down the biosolids was done at a minimal cost.

"I am immensely proud of our dedicated team whose innovative spirit turned a challenge into an opportunity,” City Manager Jeff Fiegenschuh said. “Their commitment and creativity in implementing the sludge management program not only shows their expertise but also contributes significantly to the well-being of our community and the environment. Kudos to the team for their outstanding work!"

What does the future hold?

Lanning says the material will continue to be available to local farms in the coming years.  An annual or bi-annual survey will be sent to local farmers to gauge interest.