Advanced filtration technology by Aqua Innovations is removing phosphorus from the watershed by turning manure into clean water.
The system is an add-on to the EnTech Solutions and Northern Biogas joint manure digester facility in Middleton. The biogas facility turns waste from local dairy farms — totaling about 4,000 cows — into renewable energy. Currently, the plant produces electricity. In early 2022, the methane will be processed into renewable natural gas.
The byproducts of the digester is a solid — soft bedding or compost — and a liquid — odorless manure. The Aqua Innovations system takes the liquid manure and further filters it into three liquid products — nitrogen and potassium fertilizer, phosphorus fertilizer, and clean water.
This reduces the hydraulic load for farmers, resulting in less trucks on the road and less chance of runoff, says Scott Hynds, a service technician for Aqua Innovations.
The water is discharged into surrounding lakes and streams. The phosphorus fertilizer goes to farms outside of the watershed. Using these fertilizers means farmers don’t have to purchase nutrients for their fields, Hynds explains.