New technology that transforms cow manure into water clean enough to be discharged into local waterways is now at work in the town of Springfield.
Dane County Executive Joe Parisi said the $1.6 million Nutrient Concentration System, which is likely the first of its kind in the United States, aims to preserve farm families’ way of life while also cleaning area lakes.
“By partnering with farmers and industry leaders, we are able to explore new technologies to manage manure while improving farmers’ bottom line and protecting our local water resources,” Parisi said in a statement Tuesday. “In order to continue to make progress toward our water quality goals, we need to address these challenges head on as a community.”
Parisi announced the new technology at the community digester site, which is receiving digested manure from GL Dairy Biogas LLC.
Manure contains lake-damaging phosphorous, and according to 2018 data, about 250 dairy farms with 55,000 dairy cows — producing about 300 million gallons of manure — make their home in Dane County. The county estimates that farmers spend more than $3.5 million annually on hauling and applying manure in Dane County.
AQUA Innovations’ technology will clean manure through a series of ultrafiltration and reverse osmosis filters before discharging the remaining water into Pheasant Branch Creek. The water will be cleaned to a high enough quality where it would be safe to drink.
Nutrients, including phosphorus, are removed from the manure, concentrated and stored for future use as fertilizer.
Phosphorus is particularly damaging to lakes. One pound of phosphorus can grow 500 pounds of hazardous algae, according to the county.
The new technology is expected to achieve nearly 100% phosphorus removal, which would mean less phosphorus-packed manure and digester byproduct being spread on fields sensitive to runoff in the Yahara Watershed.
“This system will deliver millions of gallons of crystal-clear water to the watershed, improving the dairy business model and the environment simultaneously,” said John Sorenson, CEO at AQUA Innovations, in a statement. “We appreciate Dane County’s commitment to projects like this and we look forward to bringing the AQUA Innovations solution to other dairy farms and communities in Dane County and beyond.”
The town of Springfield's project is among a number of strategies the county has taken to support lake clean-up efforts.
In the Waunakee area, another digester collects manure from three local farms and separates solids from liquids for use as nutrients for crops. Methane gas is collected at this facility, cleaned and then transported to Dane County’s Landfill Offloading Station where it is sold as renewable natural gas (RNG).
Dane County hopes RNG revenue sales will spark development of more digesters for local farms and increase lakes clean-up efforts.
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