The future of using manure digesters to clean Dane County’s lakes could be in jeopardy if funding for a technology that further processes discharge from digesters is not added back into the 2016 budget, supporters say.
The county’s environmental committee voted 4-0 to remove from the 2016 capital budget $500,000 to install so-called nutrient concentration technology at a county-sponsored manure digester in the town of Springfield that would remove nearly all lake-fouling phosphorus from liquid manure while producing potable water and concentrated fertilizer.
The County Board had set aside $300,000 for the project in the 2013 budget and $500,000 more in both the 2014 and 2015 budgets.
The $500,000 included in County Executive Joe Parisi’s proposed 2016 budget was to be the final piece, but now, opponents say the cost of the technology is too high compared to other phosphorus reduction strategies.
County Sups. Tim Kiefer, 25th District, Waunakee, and Carl Chenoweth, 35th District, Stoughton, supported the amendment at the Environment, Agriculture and Natural Resources Committee after hearing a Strand and Associates calculation that over 20 years, the technology would cost $220 per pound of phosphorus diverted from lakes.
A 2012 Clean Lakes Alliance plan suggested that the technology would cost $98 per pound over that same span. The county’s Personnel and Finance Committee held a special meeting on the matter Monday, where Rachel Lee, a Strand consultant, told officials the per-pound cost drops to $80 when considering the technology’s $5 million total cost. The private company that owns the digester, Gundersen Health System, will contribute a significant portion of that in operating and maintenance expenses.
The Clean Lakes Alliance’s goal is to divert 50,000 pounds of phosphorus per year using digesters and other strategies. At $220 per pound, the strategy would rank among the most expensive in the Clean Lakes Alliance plan, prompting Kiefer to question why the $80 amount was not presented when his committee considered the item last week.
“Right now, given the way the numbers are bouncing around, I wouldn’t feel comfortable investing what would end up being $1.8 million in taxpayer money into this,” Kiefer said after Monday’s meeting. “I wouldn’t rule it out for the future, but I don’t think we’re appropriate to do it at this time. … I think it’s time to put it on hold and do more work to figure out how much it’s going to cost because we’ve had three significantly different numbers in the last 10 days.”
Digesters have become an integral part of the county’s plan to reduce algae growth in the Yahara Watershed’s lakes, with two operating in the towns of Springfield and Vienna and at least three more suggested.
Neither digester currently has a nutrient concentration system, but adding the technology at the Springfield facility would boost phosphorus extraction from around 3,000 pounds per year to more than 4,000 pounds per year, said Josh Wescott, chief of staff for Parisi.
The move to remove the money “is jeopardizing the future of clean lakes, period,” Wescott said. “Two-thirds of the solution to cleaning the lakes rests in digesters and nutrient concentration systems. … I don’t know why the people who have opposed this supported it in the last three budgets.”
Deleting the funding “sends the wrong message at the wrong time” as the county prepares to work with a new operator at the Vienna digester, Wescott added.
Clear Horizons tentatively sold the Vienna digester, near Waunakee, last month to San Francisco-based Clean Fuel Partners after five years of operation. The digester was plagued by spills during Clear Horizons’ ownership.
Pending approval of the sale by the County Board, Clean Fuel has told county officials it hopes to develop other digesters and nutrient concentration systems throughout the area, Wescott said.
If the money is not added back into the 2016 budget, the funds set aside in previous years could be used elsewhere, and supporters said that would damage the prospects of similar futures projects at other digesters.
The proposed upgrade would use reverse osmosis filtering to further process the discharge from the digester. The result would be water clean enough for animal consumption, crop watering or for discharging into surface water, according to a 2013 study prepared by U.S. Biogas.
The study found equipment prices ranged from $1.1 million to $2.3 million with estimated annual operating costs of $249,000 to $329,000. Four companies submitted proposals by a Dec. 12 deadline, and last month Parisi announced that Beloit-based Aqua Innovation had been selected to install the treatment system at the county-sponsored digester owned by Gundersen Health System.
At Monday’s meeting, supporters said the nutrient concentration systems could make digesters more economically viable by removing water and producing a condensed fertilizer that is cheaper to haul over greater distances. Installing the system would reduce the volume of liquid phosphorus by about 50 percent.
“You have much less volume here, much higher nutrient concentration. You can afford to truck it farther,” Lee said. “... Having this allows you to take your phosphorus and nitrogen to the far-away fields.”
The Personnel and Finance Committee is expected to vote on the budget item next week.