By Roberta Baumann
Clear Horizons, operators of the manure digester just north of Waunakee, have implemented improvements to prevent spills and other incidents, according to information provided to Dane County.
Dane County Supervisor Tim Kiefer shared with the Tribune Clear Horizon’s responses to a set of questions he posed after a representative from the company walked out of a county committee meeting recently.
In an email to the Tribune, Kiefer, who represents Waunakee and a portion of the Town of Westport, seemed somewhat reassured by the Clear Horizons correspondence.
“While I remain concerned about the history of accidents at the Vienna manure digester over the past year, I am pleased to see that Clear Horizons has added staff, including four certified wastewater treatment plant operators and a new Chief Operating Officer who is a licensed professional engineer,” Kiefer wrote in his email.
The digester has had three leaks since last November, and in August, one of three manure processing tanks caught fire after it was cleaned. Those incidents caused alarm and shed light on a history of problems at the plant, which was built with public funds to remove algae-producing phosphorus from manure and prevent it from reaching the Lake Mendota watershed.
Clear Horizons has indicated that currently, two of three of the manure processing tanks are operational, collecting manure from three area farms.
“Manure digesters are a key part of the county’s plan to clean up the lakes, and it is important that we get this done right,” Kiefer said. “The overarching goal is to clean up the lakes by preventing manure runoff,” he added
Clear Horizon’s letter notes that the plant is currently staffed at all times, and that redundancies are being added to automation and safety features of the plant.
It also indicates that the fire remains under investigation.
As for the previous pipeline spills, the letter notes that flexible fittings have been added, preventing pipe cracks, along with more control valves. Also, the stormwater retention system has been modified to contain any spill. Shifts are also staffed whenever manure and components are pumped, the letter states.
Kiefer also asked Clear Horizons to explain why the plant had failed to meet Department of Natural Resources requirement of 60 percent reduction of phosphorus.
The letter states that sand in the manure has caused equipment problems, but new equipment should be able to remove it, allowing Clear Horizons to meet the requirement.
“In any case, the plant will continue to remove phosphorus in addition to the 100 tons it has already removed, provide jobs to the local community, process manure from partners allowing them to build their dairy business and generate electricity while reducing carbon release,” Clear Horizons COO Norm Doll responded in the letter.
Doll, who has recently hired at Clear Horizons, is a licensed professional engineer, the letter notes.