Parisi: Digester a ‘gamechanger’ in keeping water clean

New manure digester to push forward clean lakes and streams effort
Parisi: Digester a ‘gamechanger’ in keeping water clean

Dane County represents the completion of the third manure digester in the county and moves the effort to clean lakes and stream one step closer. 

The digester, which is just outside Middleton, will process approximately 100,000 gallons of manure a day with an initial goal of removing 60 percent of the phosphorus. When an upgrade is made to the plant later this year it is hoped 100 percent of the phosphorus will be removed.

“This is really game-changing in our efforts to clean our water. We’ll have manure coming in and at the end of the day, 100 percent of the phosphorus will be eliminated once the additional technology is put in place,” Dane County Executive Joe Parisi said.

The removal of the phosphorus is critical to cleaning lakes and streams in the county. Phosphorus that runs off of fields fertilized with manure is blamed for the growth of algae in those waterways.

The process also generates green energy. Gunderson Health System, the company operating the digester, expects to generate 16 million kilowatt hours of electricity annually, which will be used by the community. 

With that electricity Madison Gas and Electric will be able to provide power to approximately 2,500 homes.

“This is state of the art with many built in safety redundancies, a top-notch operator, and top-notch owners, so we’re really excited about the contribution it is going to make to cleaning up our lakes as well as producing green energy,” Parisi said.

The digester will serve three Dane County dairy farms and the manure will be processed in three air-tight digester tanks.

The opening of this new digester comes on the heels of a troubled year at a digester in the town of Vienna. 

That digester, which is operated by Clear Horizons LLC, has experienced three separate manure spills and a fire. 

The first spill occurred on Nov. 24-25, 2013, in which 380,000 gallons of liquid manure spilled from the digester when a pipe burst. A small amount of that liquid reached nearby Six Mile Creek. 

Less than two months later, on Jan. 20 and 21, another 20,000 gallons of liquid manure were spilled, again as a result of a burst pipe. 

On March 12 an additional 35,000 gallons of liquid manure were spilled.  Most recently, on Aug. 6, one of the manure digester tanks caught fire.  The fire resulted in damage to the facility. 

It also resulted in a call for Clear Horizons to relinquish operations at the facility.  On August 10 Tim Kiefer, the supervisor representing District 25 sent a letter to Clear Horizons requesting their removal. 

The company only recently responded to Kiefer’s letter by stating they planned changes to the operation of the facility. 

Kiefer said additional staff has been hired, including individuals certified in wastewater treatment. 

Additionally, Clear Horizons has agreed to replace some equipment. 

“There is disappointment with the past; however, I’m more focused on the future,” Kiefer said.

He said, regardless of the problems plaguing the Vienna digester, he believes in the future of the technology.

“The example I like to use is that in the early years of airplanes, a lot of planes crashed, and we learned from that and over the years we got to the point now where air travel is actually very safe, and it is kind of that way with digesters,” Kiefer said.

The new digester outside of Middleton has different operators and technology from the one in Vienna and officials believe that will make a difference.

“Most importantly it is a different owner, different operator and it has many built in safety redundancies,” Parisi said.