Local Permitting Requirements

Anaerobic digesters may be subject to local government permitting requirements for a range of municipal issues, such as construction, zoning and stormwater. Contact your local government to determine current rules before constructing or operating an anaerobic digester.

State Permitting Requirements

State agencies administer federal regulations and have their own air, solid waste and water permitting requirements that may apply to anaerobic digesters.

Before You Begin: Contact your state environmental agency to determine current rules before constructing or operating an anaerobic digester.

Air

• Combustion devices may require state air permits if the devices are operating over federal thresholds. These federal requirements are administered through state agencies.
• Some states have additional state-specific thresholds that require state air permits.

Solid Waste

• Waste processing facilities are required to meet Resource Conservation and Recovery Act (RCRA) Subtitle D requirements—which covers non-hazardous solid wastes—and 40 CFR Part 258—which covers landfills. These federal requirements are administered through state agencies.
• If codigestion is planned for an anaerobic digester or a facility accepts offsite waste, additional state permits may be required.
• In many cases, manure-only anaerobic digesters are exempt from solid waste permitting requirements.

Water

• If an anaerobic digester or Concentrated Animal Feeding Operation (CAFO) directly discharges to U.S. waters, a National Pollutant Discharge Elimination System (NPDES) permit is required. This is a federal requirement administered through state agencies.
  • NPDES Implementation Information
  • Large CAFOs that discharge must be permitted and develop and maintain Nutrient Management Plans to ensure appropriate land application of manure.
  • Smaller farms also may be required to comply with the rule if they discharge to waters of the United States through a manmade device or through direct contact of the animals with waters of the United States.
  • Certain states may also include smaller farms in their animal feeding operations programs.

State-Specific Requirements

View a summary overview

• California

  Permit Guidance for Anaerobic Digesters and Co-Digesters (PDF) (92 pp, 2 MB), California Environmental Protection Agency

  Consolidated or General Permit Process

  • A consolidated permit process is offered for dairy digester projects by the California Environmental Protection Agency (Cal/EPA).

  Air

  • State-specific Thresholds: The California Air Resources Board (CARB) oversees 35 districts; each district has different permit requirements depending on air quality attainment status.

  Solid Waste

  • CalRecycle is the agency responsible for solid waste permitting.
    • For solid waste, anaerobic digestion of compostable material is regulated under the Compostable Materials Handling Operations and Facilities Regulatory Requirements, Title 14, CCR 17850.
    • If the feedstock is not compostable, the required permit will depend on the feedstock and amount as well as the anaerobic digester location.
  • Codigestion: Facilities with up to 12,500 cubic yards of "green material" at any one time will require a permit if any food waste is included.
  • Manure-only Exemption: Some anaerobic digesters are exempt if they digest only "agricultural material" with less than 500 cubic yards of "green material" (which may be up to 10 percent food material by volume) at any given time, and do not sell or give away more than 1,000 cubic yards of compost annually.
  • In September 2014, the Governor of California signed legislation that requires commercial businesses to recycle organic waste. By April 2016, businesses that generate 8 cubic yards or more of food scrap and yard waste per week must separate these materials for recycling. Businesses that generate 4 cubic yards or more of organic waste per week must comply by January 2017. By January 2019, businesses that generate more than 4 cubic yards of commercial solid waste will be required to recycle organic waste.

  Water

  • The California Department of Water Resources is responsible for managing water resources within the state of California.
  • Codigestion: The Central Valley Region Waste Discharge Regulatory Program offers general permits for dairy manure and codigestion anaerobic digesters and centralized dairy manure and co-digestion anaerobic digesters. The majority of farms in California are in the Central Valley Region.
• Idaho

  Air

  • The Idaho Department of Environmental Quality (IDEQ) administers air permitting.

  Solid Waste

  • The Idaho State Department of Agriculture (ISDA) regulates anaerobic digesters processing only manure.
  • Codigestion: IDEQ regulates anaerobic digesters processing organic waste other than manure as processing facilities under its Solid Waste Management Rules.

  Water

  • The Idaho Department of Water Resources regulates water permitting.
  • CAFO: ISDA has jurisdiction over the construction and management of dairy and CAFO waste systems.
• Illinois

  The Illinois Environmental Protection Agency administers all permitting.

  Solid Waste

  • Codigestion, Offsite Waste Acceptance: Anaerobic digesters processing manure from other farms or other organic materials from off-site are considered a waste processing facility and require a permit unless they meet certain exemptions.
    • Illinois state code 415 ILCS 5, Section 3.330(a)(19) lists these exemptions.
  • Manure-only Exemption: Anaerobic digesters processing only manure are exempt from solid waste permitting requirements.
• Indiana

  The Indiana Department of Environmental Management (IDEM) administers all permitting.

  Air

  • IDEM’s Air Quality Permit Guide website contains information on air permitting and application forms.
  • State-specific Thresholds: Air permits are required prior to construction and operation for all new emission sources if a combustion device is present.
    • A combined construction and operation permit program exists.
    • 326 IAC 2-1.1-3 includes some air permit exemptions.

  Solid Waste

  • Offsite Waste Acceptance: 329 IAC 11.7 [PDF] (13 pp, 79 K) regulates facilities that store industrial process waste or commercial solid waste, or accept and process waste from offsite sources as an alternative fuel source.
  • Manure-only Exemption: There are no solid waste permitting requirements for anaerobic digestion systems processing only manure.

  Water

  • CAFO: The Confined Feeding Control Law regulates confined feeding operations (CFOs).
    • A CFO is defined by Indiana law as any animal feeding operation engaged in the confined feeding of at least 300 cattle, 500 horses, or 600 hogs or sheep, or 30,000 fowl, such as chickens, turkeys or other poultry.
    • CFOs are required to meet siting and design requirements.
    • CFOs do not need to develop a site-specific Nutrient Management Plan, but they must follow prescribed Nutrient Management Plans.
  • Codigestion: Anaerobic digesters processing organic waste in addition to manure may be required to perform additional screening of either the anaerobic digester influent or effluent.
• Iowa

  The Iowa Department of Natural Resources administers all permitting.

  A 2009 presentation on the Iowa anaerobic digester experience (PDF) (22 pp, 1.5 MB) provides general information on anaerobic digestion permitting requirements in Iowa.

  Solid Waste

  • Codigestion: Anaerobic digesters processing organic wastes in addition to manure may require solid waste permits. Facilities are evaluated on a case-by-case basis.
  • Manure-only Exemption: There are no solid waste permitting requirements for anaerobic digesters processing only manure.

  Water

  • Codigestion: If organic waste streams are added to the anaerobic digester, special requirements related to volume, nitrogen, and phosphorous content of the other waste are placed in the permit and Nutrient Management Plan to ensure that the operation has enough storage and appropriately applies all nutrients.
• Maine

  The Maine Department of Environmental Protection (DEP) administers all permitting.

  Solid Waste

  • Offsite Waste Acceptance: If a facility is digesting manure and residual/solid waste from offsite, a DEP license is required.
  • Manure-only Exemption: A DEP license is not required for facilities digesting only manure and agricultural wastes.
  • Waste discharge licenses for liquid or agronomic utilization licenses for solids may be required, depending on the end use or waste disposal of the digestate.
• Massachusetts

  The Massachusetts Department of Environmental Protection Executive Office of Energy and Environmental Affairs administers all permitting.

  The Mass.gov Anaerobic Digestion & Organics Diversion Website provides information about anaerobic digestion and organics diversion.

  Solid Waste

  • Offsite Waste Acceptance: 310 CMR 16.04 (PDF) (57 pp, 381K) specifies that anaerobic digesters that receive no more than 100 tons per day of organic material from onsite or offsite (based on a 30-day rolling average) are eligible for a general permit.
  • Facility siting for anaerobic digesters does not require a solid waste site assignment.
  • Any organization that disposes of at least one ton of organic waste a week must donate useable food and then ship any remaining food waste to an anaerobic digester or to composting and animal-feed operations.
• Michigan

  The Michigan Department of Environmental Quality (DEQ) administers all permitting.

  Fact sheet on Michigan anaerobic digester regulations (PDF) (6 pp, 352K).

  Air

  • State-specific Thresholds: Generally, manure-based anaerobic digesters are exempt from air permitting requirements unless they are combusting onsite and the combustion device produces more than 1 pound of sulfur dioxide an hour or has a heat input capacity of greater than 10 million Btu per hour. There is no difference in air permitting if organics are included.

  Solid Waste

  • Codigestion:
    • If a material other than manure is added to the anaerobic digester, authorization may be required before composting or land-applying the solids.
    • Materials that are exempt from permitting (PDF) (4 pp, 465K) may include food processing residuals, syrup from ethanol production, and grease trap wastes that do not contain septage and fish wastes. To be exempt, the anaerobic digester must accept less than 20 percent other organics.
    • Each facility is encouraged to work with the Michigan DEQ to determine what might be required.
  • Manure-only Exemption: There are no solid waste permitting requirements for anaerobic digesters processing only manure.

  Water

  • Anaerobic digesters accepting only manure are generally not required to obtain additional water discharge permits.
  • CAFO: Permitted CAFOs must include the anaerobic digester in their Nutrient Management Plan.
  • Codigestion: If other organics will be included in the anaerobic digester, a permit or authorization might be required for land application. Each facility is encouraged to contact the Michigan DEQ’s Water Bureau to discuss the requirements.
• Minnesota

  The Minnesota Pollution Control Agency administers all permitting.

  Energy from Waste: Anaerobic Manure Digestion Website (Minnesota Department of Agriculture) provides information and resources.

  Solid Waste

  • Codigestion: Solid waste requirements for anaerobic digesters that process manure and other organic waste are included in an individual permit with the water permit information.
  • Manure-only Exemption: Anaerobic digesters processing only manure have no solid waste permitting requirements.

  Water

  • CAFO: If the anaerobic digester processes only manure, it must meet the requirements of a CAFO permit or a general state disposal system permit.
  • Codigestion: If the anaerobic digestion system includes other organic wastes, it requires an individual permit.
• Nebraska

  The Nebraska Department of Environmental Quality administers all permitting.

  The One Stop Permit Assistance Program guides businesses and industry through the permitting process.

  Air

  • Nebraska Title 129 Air Quality Regulations.

  Solid Waste

  • Nebraska Title 130 Livestock Waste Control Regulations.

  Water

  • NPDES: All livestock waste control facilities must obtain a NPDES permit.
• New York

  The New York State Department of Environmental Conservation administers all permitting.

  Air

  • State-specific Thresholds:
    • Fugitive emissions must comply with 6NYCRR212 (General Process Emission Sources) and 6NYCRR211.1 (General Prohibitions).
    • New York regulations for Air Resources, Subpart 201-5 establishes criteria for facilities that are not considered to be major but require a permit.

  <5h3 class="highlighted">Solid Waste

  • New York regulations for Quality Services, Part 360-5 applies to composting facilities.
  • Solid Waste and Water Regulatory Requirements for Wastes Managed on a Farm (PDF) (11 pp, 151K)
  • Codigestion:
    • An anaerobic digester located on a CAFO that has a Comprehensive Nutrient Management Plan may accept non-manure waste up to 50 percent (by volume of their annual waste received) to qualify for an exemption from Part 360 permitting requirements.
    • A permit is required if the anaerobic digester is processing more than 50 percent non-manure waste.
  • Manure-only exemption: Anaerobic digesters that accept manure, bedding, crop residues and farm waste do not need a Part 360 permit.

  Water

  • Solid Waste and Water Regulatory Requirements for Wastes Managed on a Farm (PDF) (11 pp, 151K)
  • Generally, if the farm is a CAFO, the CAFO permit will cover the anaerobic digester and no additional water permit will be required, even if the farm is processing food processing waste.
• Ohio

  Air

  • The Ohio Environmental Protection Agency (EPA) is responsible for air permitting.
  • A general permit for anaerobic digestion systems is available. Model general permits are available for biomass digester systems utilizing a flare, digesters with gas-fired boiler, and digesters with a gas-fired, spark ignition internal combustion engine.

  Solid Waste

  • Codigestion:
    • The Ohio Department of Agriculture issues permits for anaerobic digesters accepting manure only and less than 25 percent by volume of organic wastes, as long as the facility complies with its Nutrient Management Plan. Approved organic materials include preconsumer food wastes, grease trap wastes and similar organics. Biosolids, septage, or other similar types of wastes are not allowed.
    • The Ohio EPA becomes involved in the permitting process and a separate permit may be required for anaerobic digesters processing more than 25 percent of other organic wastes.

  Water

  • The Ohio EPA and the Ohio Department of Agriculture manage water permitting.
  • Ohio Revised Code (ORC), Chapter 6111 exempts animal waste disposal systems from additional water permits. Anaerobic digesters that treat 75 percent or more animal manure and are located on a permitted CAFO will not require an additional permit.
  • NPDES: Anaerobic digesters not located on a CAFO that accept any industrial/commercial wastes must be approved by Ohio EPA under ORC 6111 through a permit to install and land application management plan (if no sewage sludge is digested) or a permit to install and NPDES permit (if sewage sludge is digested).
  • Codigestion: When materials other than those generated on the farm are added to the anaerobic digester, the anaerobic digester becomes classified as an industrial waste system and a permit is required.
• Oregon

  The Oregon Department of Environmental Quality administers all permitting.

  Air

  • State-specific Thresholds:
    • Anaerobic digesters with combustion devices operating below federal thresholds require a Simple Air Contaminant Discharge permit if the system emits at least 10 tons per year of NOx or CO or 5 tons per year of PM.
    • Anaerobic digesters with combustion devices operating above federal thresholds require a Standard Air Contaminant Discharge permit.

  Solid Waste

  • OAR 340, Division 96 regulates solid waste composting facilities, including anaerobic digesters. A composting facility permit or registration is required under OAR 340-096-0080(3)(b): Screening.

  Water

  • An anaerobic digester processing only manure at permitted CAFOs does not require an additional permit, but needs to be incorporated into the existing permit and Nutrient Management Plan.
  • Anaerobic digesters operating without CAFO permits may require a water permit, depending on the facility.
  • Codigestion: Anaerobic digesters processing other organic wastes in addition to manure require state agency review of the system to determine which permits apply. Anaerobic digesters at permitted CAFOs that accept other organics have not required additional permits.
• Pennsylvania

  The Pennsylvania Department of Environmental Protection administers all permitting.

  Consolidated or General Permit Process

  • A General Permit (WMGM042) (PDF) (8 pp, 51K) authorizes anaerobic digestion of a mixture of wastes that include animal manure, grease trap waste, pre-consumer food, and wastewater from dairy farms. The coproducts must be used in certain beneficial use conditions, including: using generated methane gas as an alternative fuel for electricity generation; using waste solids from the digester as bedding material for animals at the farm; and using liquid wastewater from the digester as a soil additive for agricultural purposes, as long as the wastewater does not exceed 15,000 milligrams per liter of fats, oil and grease.

  Solid Waste

  • Anaerobic digesters, including those that digest food processing waste, do not require a solid waste permit for land application.

  Water

  • Farms producing or using manure are required to have a Nutrient Management Plan. Most anaerobic digesters (including those that digest only manure and those that digest manure plus other organics) require a Water Quality Part II permit.
• Texas

  The Texas Commission on Environmental Quality (CEQ) administers all permitting.

  Air

  • State-specific Thresholds: State authorization via the Permits by Rule (PBR) is required for facilities that are operating below federal thresholds but with more than de minimis levels of emissions.

  Solid Waste

  • Anaerobic digesters are permitted on a case-by-case basis. Contact the CEQ to determine the requirements.

  Water

  • Permitting requirements are case-specific depending on the location, how the anaerobic digester fits within the permitted activity, and the type of material being digested. Contact the CEQ to determine the requirements.
• Vermont

  Air

  • The Vermont Department of Environmental Conservation administers air permitting.
  • Generally, anaerobic digesters do not require a permit provided they meet the following requirements:
    • the combustion device meets federal thresholds;
    • the engine exhaust stack is vented a minimum of 4 feet above the nearest roof;
    • the backup combustion device meets the requirements of 40 CFR Part 60, Subpart A 60.18; and
    • the emissions source is registered with the agency in accordance with Vermont Air Pollution Control Regulations (PDF) (178 pp, 561K), Subchapter VIII.
  • The inclusion of substrates other than manure typically does not require additional permits, but each substrate is reviewed on a case-by-case basis.

  Solid Waste

  • The Vermont Department of Environmental Conservation administers solid waste permitting.
  • Codigestion: If more than one ton (dry weight) of food waste generated offsite is added to an anaerobic digester, the state solid waste program permits the system and the system may qualify for a categorical certification.
  • Manure-only exemption: Anaerobic digesters processing only manure do not require a permit.
  • Vermont Act 148 mandates that all residential food scraps be recycled at an organics recycling facility unless there is no organics recycling facility within 20 miles.

  Water

  • The Vermont Agency of Agriculture administers water regulations for anaerobic digesters.
  • Anaerobic digesters processing only manure do not require additional permits.
  • The Vermont Agency of Natural Resources coordinates with the Agency of Agriculture for projects with land application to determine available manure pit capacity for the additional organics effluent as well as nutrient loading limits for the farm. Indirect discharge permits per 10 V.S.A. §1263 are issued to the generators of the other organics, with the approved farms identified in the appendix of the permit.
  • Codigestion: If other organic wastes are included in the anaerobic digester, an indirect discharge permit for land application of the effluent may be required.
• Washington

  The Washington State Department of Ecology administers all permitting.

  Air

  • State-specific Thresholds: WAC 173-400-110(5) requires that anaerobic digesters that emit more than a de minimis amount of air pollution annually per must be permitted as a new source and requires a Notice of Construction air quality permit.
  • A General Order (PDF) (6 pp, 320K) is applicable to a new or modified dairy manure anaerobic digester that meets approval conditions as stated in the General Order Permit and operates in a county regulated by the Department of Ecology. Approval conditions include operation and emission limitations, restrictions, required plans, general conditions, and monitoring, recordkeeping and reporting requirements.

  Solid Waste

  • Solid Waste Facilities and the Permitting Process
  • The Solid Waste Handling Standards, Chapter 173-350 WAC, includes permitting requirements for solid waste anaerobic digesters (WAC 173-350-250).
  • Manure-only Exemption:
    • Per RCW 70.95.330, an exemption from solid waste handling permits may be provided for anaerobic digesters that contain at least 50 percent manure and no more than 30 percent other organic waste.
    • Table 250-A of WAC 173-350-250 lists exemptions. Feedstocks not listed in Table 250-A must be approved by the Department of Ecology.

  Water

  • Anaerobic digesters operating at permitted CAFOs do not need an additional permit if the system is digesting only manure.
  • Codigestion: If the system is digesting organic wastes in addition to manure, the Nutrient Management Plan must be modified to reflect these wastes.
• Wisconsin

  The Wisconsin Department of Natural Resources administers all permitting.

  Solid Waste

  • Codigestion:
    • A CAFO operator must obtain approval before including any additives other than manure to an anaerobic digester.
    • Under NR 243.17, additional permit requirements may apply if the additives comprise more than 10 percent of the total volume of material in the anaerobic digester or if the state determines that the additives warrant it.

  Water

  • Anaerobic digesters operating at permitted CAFOs do not need additional permits if the system is digesting only manure.
  • Codigestion: If the anaerobic digester is digesting organic wastes in addition to manure, authorization is needed and a permit may be required.

Federal Regulatory Requirements

Air

State air permits may be required if on-site combustion devices trigger federal emissions thresholds and other federal regulatory permitting requirements. Combustion devices with air emissions below federal thresholds may avoid permitting requirements. Federal thresholds are documented in the following regulations:

• Control of Emissions from New and In-Use Nonroad Compression-ignition Engines, provides federal emission standards for non-road internal combustion engines. (40 CFR Part 89)
• Standards of Performance for New Stationary Sources (40 CFR Part 60)
  • Standards of Performance for Stationary Spark Ignition Internal Combustion Engines (40 CFR Part 60, Subpart JJJJ)
  • Standards of Performance for Stationary Compression Ignition Internal Combustion Engines (40 CFR Part 60, Subpart IIII)
  • Standards of Performance for Industrial-Commercial-Institutional Steam Generating Units (40 CFR Part 60, Subpart Db)
  • Standards of Performance for Small Industrial-Commercial-Institutional Steam Generating Units (40 CFR Part 60, Subpart Dc)
• Industrial, Commercial, and Institutional Boilers and Process Heaters (40 CFR 63, Subpart DDDDD)
• Stationary Internal Combustion Engines (40 CFR Part 63, Subpart ZZZZ)
• EPA's National Ambient Air Quality Standards – Identifies emissions standards for criteria air pollutants (ozone, PM, CO, NO_x, sulfur dioxide, and lead)
• Emissions Standards for Boilers and Process Heaters and Commercial / Industrial Solid Waste Incinerators

Solid Waste

Federal laws do not require solid waste permits for manure. However, the acceptance of other organics may designate the anaerobic digester as a waste processing facility in some states.

Waste processing facilities are required to meet federal regulations:

• Managing Non-Hazardous Municipal and Solid Waste, Resource Conservation and Recovery Act (RCRA) Subtitle D
• Criteria for Municipal Solid Waste Landfills, 40 CFR Part 258

Water

A National Pollutant Discharge Elimination System (NPDES) permit (PDF)(38 pp, 217K) is required for Concentrated Animal Feeding Operations (CAFOs) that discharge or propose to discharge to U.S. waters including:

• Inappropriate land application of manure
• Discharge to waters of the United States through a manmade device or through direct contact of the animals with waters of the United States.