Decorah Leader 9-25-25 – Reader cites ‘false equivalencies made and meaningless statements’ during ag digester discussion
My name is Bob Watson. I have made my living in the wastewater industry. I have 30 years experience with both wastewater and agricultural anaerobic digesters. During the presentations for the ag digester west of Ridgeway there have been false equivalencies made and meaningless statements provided to gain permission to build that digester.
Novilla has stated that because the wastewater industry has used anaerobic digesters for years with success, that success should transfer to ag digesters. That is a false equivalency argument. Wastewater Treatment Plant (WWTP) digesters are only one part of a multi-step treatment process. Ag digesters are a stand-alone technology. WWTP’s have discharge permit limits. Ag digesters have no discharge permits and you can’t even test their discharge so you don’t know what is being land applied. WWTP digesters have federal OSHA and Iowa DNR operational regulations they must follow which provide education and protection for workers, the public, and the environment. In Iowa ag digesters have none of those regulations.
Iowa WWTP digesters have state licensed operators running them that must get Continuing Education Units to keep their licenses up to date. There is no requirement for licensed operators in ag.
I was a member of the DNR TAC committee that was writing regulations for ag digesters. When the Iowa Legislature found out we were writing those regulations they passed a law that said you couldn’t regulate ag digesters in Iowa. Novilla stated it would follow all regulations. That is a meaningless statement as there are no regulations for digesters in ag in Iowa.
Novilla stated there would be no toxic/hazardous waste going into their digester. This is another meaningless statement. All ag confinement waste in Iowa, whether dairy, hog, or chicken confinement waste meets Iowa’s definition of hazardous waste. When I made the DNR Chair of the TAC committee aware of this hazardous waste problem, his answer to me was that the feds and the state say that because this is ag, this waste cannot be described as hazardous. I quote: “The Code citation is a legislative decision and matches the federal exclusion. I don’t believe Iowa DNR can do anything contrary to the state and federal statutes.” So something that is known to be a hazardous waste is not a hazardous waste in ag just because the feds and the state say it isn’t.
Even though the Iowa Nutrient Reduction Strategy (INRS) is voluntary for agriculture, it is not for wastewater treatment plants which were given more strict discharge limits that we had to meet. To meet those stricter limits, many plants have moved away from anaerobic digesters to aerobic digesters or tertiary treatment. Ag has adopted an older technology with no regulations for use in agriculture.
Bob Watson Rural Decorah