Biosolids
About the Program
The Biosolids Department consists of one (1) solids-handling lead worker and three (3) treatment plant mechanics.
Definition of Biosolids
Biosolids are primarily organic materials produced during wastewater treatment that may be put to beneficial use because they contain nutrients such as nitrogen and phosphorus that are beneficial to crops. An example of such use is the addition of biosolids to soil to supply nutrients and replenish soil organic matter. This is known as land application.
A Unique Position
The City of Muscatine is unique because it is rare for a city of its size to do its own land application instead of contracting it out. The City of Muscatine has a waiting list of farmers wanting to pay for land application. Currently 4,500,000 gallons are being applied to 550 acres in Muscatine County.
Land Application Program
The Biosolids Land Application Program consists of two (2) different application methods. The first is a dragline operation. For this application, biosolids are pumped underground to hydrants in the farm fields. A hose is attached to the hydrant and coupled to the back of a toolbar applicator. The biosolids flow through a hose from the hydrant to the toolbar applicator and are injected into the ground as the hose is dragged behind the toolbar.
The second method is a mobile operation in which biosolids are hauled to farm fields too far away for the dragline system method. Semi-tankers are used for the hauling. When the biosolids reach the field, they are transferred to a 7,400-gallon slurry tank. The slurry tank is then pulled through the field by a 380-horsepower tractor. The biosolids are injected into the ground. The farmers receiving the biosolids in the mobile application program pay a $20 per acre application fee.