Emerging Issue: Composting and Anaerobic Digestion

In 2022, Michigan updated its solid waste regulations for composting and anaerobic digestion. The changes were aimed at improving performance, oversight, and environmental protection, but can cause challenges for farmers who want to recycle organic waste, produce crop nutrients, generate energy, and improve soil health and water quality:

• Farms do not have to obtain permits for an on-farm composting facility, but they cannot charge tipping fees for outside materials, cannot sell the finished compost, and must register with the state.
• Farms composting mortality must obtain a permit if the mortality is from more than one site, or if the farm uses more than 5,000 cubic yards of bulking materials.
• The digestate produced after anaerobic digestion captures the methane must separate solids and liquids to land apply the digestate.
• Digesters often must obtain separate permits for surface water and groundwater discharge, solid waste, and air quality, which often have confusing or conflicting requirements.
• If a digester is owned by a 3rd party, receiving a mix of different feedstocks (like a combination of manure and food waste) or receiving manure from multiple farm sites, the regulations are confusing and expensive.

Member policy supports composting and differentiating between agricultural (for use on the farm) and commercial (for sale to customers) composters. Our policy also supports digestors to produce renewable energy, comingling feedstocks without additional regulation, and registering digesters without additional groundwater or surface water permits. Michigan Farm Bureau is working with stakeholders on a legislative solution to streamline and simplify permits for digesters, but we need to hear from farms on what would make composting and digesters more feasible for different farming situations.

Thoughts to consider

• Are there ways to assist farmers with on-farm composting goals? 
• Would information on transitioning to commercial composting be beneficial?
• How can farms protect themselves from contaminated materials in their composting or digester facility without creating a regulatory burden too expensive to comply with?
• What kind of registration, contract, or permit would work best for a farm if they are contributing to a digester receiving materials from multiple sources, such as multiple farms, or from food waste and manure sources?

Policy references

MFB Policy #45 Renewable and Biomass Products

MFB Policy #46 State Energy Policy

MFB Policy #87 Resource Recovery

MFB Policy #94 Taxation

Additional resources

EPA information about digesters

Michigan State University’s Anaerobic Digestion Research and Education Center 

Benefits of Biogas 

Michigan State University Compost Handling in Agricultural Systems 

Michigan On-farm Composting Registration Form

Generally Accepted Agricultural and Management Practices for Nutrient Utilization (composting information starts on page 24)