New owners of a manure digesting plant near Waunakee say they have improved the facility’s performance but a major challenge looms.
Clean Fuel Partners vice president Jessica Niekrasz said finding new customers for natural gas produced by the digester will be key to its continued operation when Alliant Energy lowers the price it pays for the plant’s gas-generated electricity four years from now.
But things look better than a year ago, when the previous owners faced scores of water and air pollution violations that culminated in a state lawsuit and an $80,000 fine.
On Wednesday morning this week, the digester is scheduled to be open to the public as the new proprietors spread the word about their efforts to generate renewable energy and chip away at environmental degradation caused by dairy farms.
More than 80 people had signed up for the tour by late last week.
Neikrasz, a resident of suburban Chicago, said she is focused on the projected 2020 revenue crunch.
An answer could come in the form of more customers for compressed natural gas to fuel cars and trucks, or a new technology that turns methane into a marketable material such as plastic, she said.
Another possibility is additional farmers contributing manure to create a more efficient economy of scale, she said.
“Part of that is seeing how big the pain in Wisconsin becomes in terms of the runoff from the farms all over the state,” Niekrasz said.
Rain and snow melt carrying farm manure into lakes and streams is the major cause of unnatural weed, algae and bacterial growth that limits swimming, fishing and boating on a growing list of public waters.
Agriculture industry manure, along with commercial fertilizer, is also the source of the most widespread health hazards in underground aquifers that supply drinking water to three-quarters of Wisconsin residents.
Just three Dane County farmers pipe manure to the digester where harmful nutrient levels are reduced and pathogens killed before it is returned to be spread on fields.
A newer multi-farm digester is being operated by another company in the town of Springfield, and some farms operate their own facilities. But the state’s runoff problems indicate there’s potential for more, Niekrasz said.
Meanwhile, under state law manure management on small farms is mostly voluntary.
The digester near Waunakee was built in 2010 for $12 million including tax subsidies. Milwaukee-based Clear Horizons operated it, but ran into problems.
A judge ordered the previous owner to pay $80,000 last year after the state cited it in spills of 400,000 gallons of manure in three incidents, repeated failure to remove pollutants from treated manure and 90 violations of air emission standards in operations of machinery.
Clean Fuel Partners announced in October it was buying the plant.
The new owner has replaced the roofs on two of the facility’s three 1.25-million-gallon digesters, large containers where manure and restaurant waste is heated and naturally occurring methane gas is collected.
The gas is burned in two engines that generate electricity that is sold to Alliant on a contract that pays 12 cents per kilowatt during peak usage times and 7.3 cents otherwise.
The contact expires in 2020, though, and the 2007 incentive program that offered higher-than-market rates to digester operators is over, said Alliant spokesman Chris DuPre.
The initial construction subsidies and energy purchase contract are what made operating the plant feasible, said John Haeckel, who was a California investment banker who specialized in debt restructuring before he formed Clean Fuel Partners to purchase the digester.
Haeckel, who now lives in Madison, said last month at a talk sponsored by the Clean Lakes Alliance that buying the facility was made possible in part by “the pound of flesh we took out of the hide of the seller when we paid them less than what they invested.”
The purchase was negotiated at about the same time the former owners were settling the lawsuit brought by the state Department of Justice based on a 2014 request by the DNR.
Nutrients go to another watershed
Clean Fuel Partners has overseen installation of a crucial new piece of equipment that was already being purchased by the former owners.
Clear Horizons repeatedly failed to meet its water pollution permit requirement to remove 60 percent of the nutrient phosphorus from the material it processed because of frequent mechanical problems with a centrifuge that separates phosphorus heavy solids from liquids.
The new centrifuge has been more reliable and efficient, plant manager Eric Schumann said.
After the manure and food waste mixture has yielded methane, it is fed into the centrifuge.
The liquid that comes out of the machine is expected to carry no more than 40 percent of its original phosphorus content, under the DNR’s water pollution permit. The three farms spread the liquid on fields.
The solid byproduct that emerges from the centrifuge with most of the potentially harmful phosphorus is dried and sold as animal bedding to a farm near Waterloo so that it doesn’t end up adding to nutrient pollution in the Yahara River or Dane County’s lakes.
The Crawfish River flows through Waterloo in Jefferson County. Like the Yahara and the Dane County lakes, the Crawfish drains into the Rock River, which has been the target of efforts to reduce nutrient pollution from farms.
In 2013 and 2014, pipes failed three times allowing manure to spill. In one case, about 300,000 gallons were released, and manure traveled more than a mile over land and through ditches to a tributary of Six Mile Creek, which empties into Lake Mendota.
Water samples from the creek showed “severe impacts by pollution,” DOJ said in the lawsuit, which was filed on Aug. 3, 2015.
After the spills, the digester installed flexible pipe fittings designed to prevent ruptures, as well as sensors that close valves and shut down pumps automatically when they detect spilled liquids or changes in pressure in pipes, said Schumann, who also worked for Clear Horizons in a variety of capacities going back to the plant’s construction.
The new owners have workers at the site around the clock except for weekend nights, Schumann said.
In 2013, a pipe rupture became the plant’s largest spill because it happened at night and went unnoticed for hours until the day shift arrived.
An alarm system failed to alert an on-call employee, a company spokesman said at the time.
The digester’s current water permit requires 60 percent removal of phosphorus. Each year the requirement will become stricter until all the phosphorus from the restaurant waste is removed, Schumann said.
Sixty percent will remain the standard for the manure portion of the material returned to the three farms to be spread on fields, he said.
The air permit has been revised to allow five times the hydrogen sulfide emissions from generators burning biogas as was allowed originally, said Tom Roushar, a DNR air management program supervisor.
Clear Horizons initially supplied incorrect information about the machinery that led to an unrealistic permit requirement, and the new limit remains well within state standards, Roushar said.