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Dane County Land & Water Resources Department

Dane County Cuts Ribbon on Cutting-Edge Technology that Turns Cow Manure into Drinkable Water

September 15, 2020
Ariana Vruwink, 608-267-8823
County Executive, Land & Water Resources

Will Advance County’s Lakes Clean-Up Efforts & Renewable Natural Gas Network While Benefiting Local Farmers

Today, Dane County Executive Joe Parisi joined representatives from AQUA Innovations and GL Dairy Biogas LLC, along with three local dairy producers to cut the ribbon on cutting-edge technology that turns cow manure from area farms into drinkable water. This community nutrient concentration system (NCS) is believed to be the first in the United States and is part of Dane County’s ongoing effort to clean up area lakes and expand its renewable natural gas network among local farms.

The $1.6 million project, which has been years in the making, is located in the Town of Springfield, and is receiving digested manure from GL Dairy Biogas LLC. The nutrient concentration system cleans manure through a series of ultrafiltration and reverse osmosis filters before discharging the remaining clean water into Pheasant Branch Creek. Nutrients, including phosphorus, are removed from the manure, concentrated, and stored for later use as a fertilizer for growing crops.

“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,” said Dane County Executive Joe Parisi. “In order to continue to make progress toward our water quality goals, we need to address these challenges head on as a community.”

Manure contains phosphorous, and due to Dane County’s large family farm economy, phosphorus reduction is critical to the effort to clean up our lakes. One pound of phosphorus is powerful enough to grow 500 pounds of hazardous algae. This new nutrient concentration system achieves nearly 100% phosphorus removal—meaning less phosphorus filled manure and digester byproduct being spread on fields sensitive to runoff in the Yahara Watershed.

Most dairy manure consists of a majority of water mixed with manure, bedding, and other farm related wastewater. Removing water from manure reduces the total volume. This volume reduction allows agricultural producers to reduce transportation costs, transport concentrated manure nutrients further distances, and reduce the amount of farm related traffic on local roads.

Concentrating the nutrients found in manure reduces the amount of commercial fertilizers needed to save producers money, increases the flexibility and timing of when concentrated manure can be applied to crop fields, and expands the types of crops that can be grown utilizing the concentrated nutrients. By removing water and concentrating the nutrients in manure, producers are able to more efficiently recycle nutrients generated on their farm while reducing the risk of phosphorus runoff to area streams, rivers, and lakes.

“AQUA Innovations is excited to be unveiling our nutrient concentration technology at Dane County’s Springfield Community Digester site,” said John Sorenson, CEO at AQUA Innovations. “This system will deliver millions of gallons of crystal-clear water to the watershed, improving the dairy business model and the environment simultaneously.  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.”

In 2018, Dane County was home to about 250 dairy farms with 55,000 dairy cows. Those cows produce around 300 million gallons of manure each year. It’s estimated that farmers spend more than $3.5 million annually on hauling and applying manure in Dane County alone. This partnership between agriculture, private businesses and the community will help reduce the amount of phosphorus reaching our water resources and help improve the water quality of the Yahara Watershed and lakes.

Dane County has also supported the creation of a manure digester in the Waunakee area. This digester collects manure from three local farms and separates solids from the digested liquids for use as nutrients for crops. Methane gas generated at this facility is collected, cleaned, and transported to Dane County’s Landfill Offloading Station, where it is sold as renewable natural gas (RNG) and put into the interstate transmission pipeline so it can be used as fuel to power fleets of RNG vehicles across the United States.

Methane is 25 times more potent to the atmosphere than carbon dioxide, and when used as renewable vehicle fuel, every trailer that comes through Dane County’s Offloading Station will reduce greenhouse gas emissions equivalent to that of burning 24,000 pounds of coal. The county is hopeful that revenue from the sales of digester RNG will spur the development of more digesters for local farms and increase lakes clean-up efforts. This new nutrient concentration system technology, combined with an industry shift to more manure digesters generating renewable natural gas, is a game changer in furthering Dane County’s efforts to manage manure, nutrients, water, and methane gases to benefit local air, water, and soil resources.

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