Committee hears testimony on bills to clarify rules for commercial and community anaerobic digesters

The Michigan House Agriculture Committee heard testimony on House Bills 4257 and 4265 aimed at clarifying regulatory standards for commercial and multi-owner anaerobic digesters and for the management and land application of digestate.

Representative Nyer, the bills’ sponsor, told the committee the package "lays out the inconsistent or consistent guidelines for both departments and operators" and is intended to make multi-owner digesters viable for investors and smaller farmers. Rob Anderson, government relations manager for Michigan Farm Bureau, told the panel, "Anaerobic digesters are a good thing," saying digesters can divert food and farm waste from landfills, make soil amendments and produce renewable natural gas. Anderson said the bills would establish standards for construction, acceptable feedstocks, traceability, training, contingency plans, recordkeeping and notification requirements.

The Department of Environment, Great Lakes and Energy (EGLE) said it supports digesters in principle but cannot support the bills in their current form. Sydney Hart, legislative liaison for EGLE, said the agency wants legislation that prevents odors, protects groundwater and ensures that harmful chemicals are not applied to farmland. Tracy Cascametti, acting director of EGLE’s Materials Management Division, described how revisions to Part 115 (Michigan’s solid waste law) created a regulatory framework for recycling operations and said digesters that produce liquid outputs may fall under Michigan’s Clean Water Act and Part 31 rather than a solid-waste pathway. Jared Sanders, director of EGLE’s Water Resources Division, said the groundwater permitting program is designed "to protect the 1,000,000 single family home drinking water wells that we have in this state" and that some digestate outputs can resemble high‑strength wastewater requiring Part 31 oversight.

EGLE staff detailed specific risks they want addressed in drafting, including odor control, storage and lagoon integrity, recordkeeping of inputs and outputs, and monitoring for contaminants. In committee back-and-forth, members raised PFAS and viscosity concerns; EGLE officials said biosolids rules for municipal sludge are not directly analogous and that a permit system should ensure groundwater protection rather than expecting digestate to meet drinking-water standards directly.

Trade groups and industry speakers proposed voluntary and third‑party testing programs as tools for regulatory confidence. Heather Dzic, vice president of policy at the American Biogas Council (ABC), described ABC’s Digestate Certification program, which ABC developed with EPA engagement. "You can think of it sort of as a nutrition label," Dzic said, adding the program requires routine sampling, lab verification and an inter-lab quality check; ABC says the program can align with or exceed federal 40 CFR Part 503 biosolids criteria depending on the sampling regimen.

Other industry testimony emphasized economic benefits and existing capacity in Michigan. Dzic told the committee Michigan "ranks fourth nationally for the amount of biogas it produces, nearly 50,000,000,000 cubic feet a year from over a 30 operational digesters in Michigan today." Dana Kirk, co‑owner and CEO of SKS Development and Taurus Biogas, said projects range from about $20 million to over $200 million to construct, employ local trades and can produce renewable natural gas or electricity on a near‑continuous basis; Kirk said uncertainty over how EGLE applies permitting to food‑waste co‑digestion has driven investment to other states.

Committee members from lakeshore and agricultural districts pressed both sides on water‑quality protections and agronomic application rates. Some members suggested the Department of Agriculture (MDARD) should play a stronger role in setting agronomic use and nutrient‑management expectations; industry witnesses generally supported MDARD leadership on agronomic rates while seeking clarity on environmental safeguards and permitting predictability.

The committee did not take a final vote on either bill during the hearing. The chair said additional testimony will continue next week.