Regulatory Requirements for On-Farm Anaerobic Digestion Facilities under Ontario Regulation 267/03

Table of Contents

Section 1: Preamble

This document describes the requirements in the Nutrient Management Regulation (Ontario Regulation 267/03 - General, as amended (O.Reg. 267/03)) made under the Nutrient Management Act, 2002, S.O. 2002, c. 4, as amended (NMA) for designing and operating an on-farm regulated mixed anaerobic digestion facility. This type of facility combines off-farm waste materials with manure and other farm-based materials while helping the environment.

The document provides plain language guidance to the regulatory requirements for on-farm mixed anaerobic digestion facilities. These regulations are legal requirements. This document is not intended to replace or supersede any provisions set out in the Waste Management Regulation (i.e. Revised Regulations of Ontario, Regulation 347 - General, as amended (Reg. 347)) and/or O. Reg. 267/03. Stakeholders should seek their own legal advice if they have concerns about the applicability of the law to their operation.

The information contained in this document is not authoritative. It is derived from the NMA and O. Reg. 267/03 and is for informational purposes only. Efforts have been made to make it as accurate as possible, but in the event of a conflict, inconsistency or error, the requirements set out in the NMA and O. Reg. 267/03 take precedence. Please refer to e-Laws for what the NMA and O. Reg. 267/03 actually provide. The Government of Ontario assumes no liability for any inaccurate or incomplete information nor for any actions taken in reliance thereon. Prior to implementing any changes to your operations, it is strongly recommended that you review the NMA and O. Reg. 267/03 directly and seek any advice you consider appropriate from a qualified person.

Section 2: Introduction

Anaerobic digestion (AD) means the decomposition of organic matter in an oxygen limiting environment. AD produces methane gas, which can be used to create an energy product (heat, electricity or natural gas). AD of farm wastes is beneficial to the environment because it provides farmers with a renewable energy source, lowers greenhouse gas emissions, and reduces odours and pathogens in the input materials.

Adding certain off-farm wastes to an on-farm anaerobic digester can make the digestion process more efficient and increase the amount of methane generated. The AD process produces a leftover material (called digestate) that has the same nutrient content as the feed material, but with less odour and fewer pathogens. If it meets applicable regulatory requirements, this material can be applied to land as a nutrient-rich organic material that benefits soil and crop growth.

Farm Based AD System Capable of Accepting Off-Farm Source Material.

Figure 1. Farm Based AD System Capable of Accepting Off-Farm Source Material.

Section 3: Rules for Off-Farm Wastes When Added to a Farm Based Digester

Unless exempt, any facility that receives and processes waste needs to obtain a Renewable Energy Approval (REA) if generating electricity for the Feed-In Tariff (FIT) Program or an Environmental Compliance Approval (ECA) under Part V of the Environmental Protection Act, R.S.O. 1990, c. E. 19, as amended (EPA) and O. Reg. 347. In addition, sites where off-farm wastes are directly land applied will require a Non-Agricultural Source Material (NASM) Plan if the materials are from categories 2 or 3. Visit the OMAFRA website to learn more about NASM plans and categories of materials.

To promote the use of anaerobic digesters on farms, there are some exemptions for the need of a REA or ECA. These exemptions are for a facility that meets the standards set out in O. Reg. 267/03 for a regulated mixed anaerobic digestion facility (RMADF) (see Section 4 below).

Note that an on-farm AD facility that uses only agricultural source material and not off-farm waste is currently exempt from approval requirements under Part V of the EPA, but will require REA approval if generating electricity for the FIT Program.

Some mixed AD facilities incorporate off-farm waste but do not meet the criteria in O. Reg. 267/03 for an RMADF. These facilities would continue to have to meet the requirements of REA or an ECA for a waste management system or waste disposal site under Part V of the EPA and O. Reg. 347. Please refer to Section 5 below for additional information on land application of the AD output from these facilities.

Section 4: Requirements for a Regulated Mixed Anaerobic Digestion Facility

The following sections describe requirements that your facility must meet to be considered an RMADF.

Nutrient Management Strategy Requirements

A facility cannot receive off-farm AD materials on a farm unit for treatment in an RMADF unless the following requirements are met:

  1. There is an approved nutrient management strategy for the farm unit on which the agricultural operation is carried out that contemplates receiving materials for treatment in an RMADF, and
  2. The AD facility is operational.

In addition to the requirements that apply to all typical strategies under the Nutrient Management Act (NMA) for a livestock farm, this nutrient management strategy must do the following:

  1. Describe the procedures that will be used at the operation to decide whether the off-farm AD material meets the requirements of O. Reg. 267/03 for treatment by mixed AD.
  2. Describe how any permanent nutrient storage facilities for storage of off-farm AD material will meet the requirements of O. Reg. 267/03.
  3. Describe the procedures that will be used at the operation to manage AD output to meet the requirements of O. Reg. 267/03.
  4. Describe how the regulated mixed AD facility will meet the requirements of O. Reg. 267/03.

All nutrient management strategies must include a contingency plan. The contingency plan sets out your actions if you cannot follow the components of your Nutrient Management Strategy or Plan. Part 12 of the Nutrient Management Protocol provides direction on what should be included in a contingency plan.

On-Farm and Off-Farm Anaerobic Digestion Material Requirements

On-farm AD material must be generated:

  • On the farm unit on which the AD facility is located, or
  • From one or more agricultural operations carried out on several farm units, if the total number of farm animals on all the farm units generates less than 2,000 nutrient units annually.

On-farm AD materials must be organic materials generated through:

  • growing, producing or raising farm animals
  • producing agricultural crops, including greenhouse crops, maple syrup, mushrooms, nursery stock, tobacco, trees and turf grass
  • producing eggs, cream or milk, or
  • processing products produced primarily from your agricultural operation

At all times the materials received for use in an RMADF must meet the following requirements:

  • At least 50 per cent, by volume, of the total amount of AD materials that are being treated in the facility must be on-farm AD materials, and
  • At least 50 per cent, by volume, of the total amount of on-farm AD materials that are being treated at the facility must be manure.

Existing facilities that are currently permitted to receive up to 25 per cent off-farm materials must first have an amended nutrient management strategy approved by OMAFRA prior to accepting up to 50 per cent off-farm materials.

Section 98.4 of O. Reg. 267/03 sets out the requirements for receiving off-farm AD materials. In one year, the total volume of off-farm AD materials received for treatment in a regulated facility at a farm unit on which an agricultural operation is carried out must not exceed 10,000 cubic metres (cu. m).

In one day, you can receive a maximum of 200 cu. m of off-farm AD materials at the operation. This limit does not apply to farm feed.

Additionally, off-farm AD materials cannot be received at the operation before 7 a.m. or after 7 p.m. No off-farm AD materials can be brought to the facility until an RMADF is constructed and ready to operate.

General Requirements for Receipt of Materials

Off-farm AD materials brought for treatment in an RMADF on a farm unit where an agricultural operation is carried out must:

  1. be materials listed in Schedule 1 or Schedule 2
  2. not be listed in Schedule 3
  3. Under the circumstances described in O. Reg. 267/03, be analyzed for metals at an accredited lab in accordance with the methods specified in the Sampling and Analysis Protocol. The person receiving the materials must have the results of the analysis before accepting delivery of the materials at the facility. If the analysis determines the concentration of metals exceeds the metal content limits set out in the Table 1, no person can accept the materials at the farm.

Table 1. Maximum metal concentration in materials.

Regulated Metal Maximum metal concentration in materials
(milligrams per kilogram (mg/kg) of total solids dry weight)
Arsenic 13
Cadmium 3
Chromium 210
Cobalt 34
Copper 100
Lead 150
Mercury 0.8
Molybdenum 5
Nickel 62
Selenium 2
Zinc 500

*Note: The regulation allows for the receipt of higher copper and zinc values (400 mg/kg and 700 mg/kg of total solids, dry weight respectively), but only if the facility also tests the contents of the digester and finds that the digester metal concentrations are lower than the metal concentrations in the table above.

If a material falls under two schedules, the schedule with the most rigorous requirements must be followed. For example, if a material falls under Schedule 1 and Schedule 2, it must be treated as a Schedule 2 material. If the material falls under both Schedule 2 and Schedule 3, it must be treated as a Schedule 3 material (which means it is not permitted for use as an off-farm material for this type of facility).

Farm feed has a specific definition in the regulation. It includes certain off-farm materials listed in Schedule 1. These materials are organic matter from food processing at fruit, vegetable, cereal and grain processing facilities, as well as from breweries, distilleries and wineries.

Two options exist for receiving off-farm AD materials. It can be received in bulk or it can be received in packaging or storage materials. However, the packaging or storage materials must not remain at the operation after the materials have been delivered. Resins and plastics that are present in a material listed in Schedule 1 or 2 cannot exceed 0.5 per cent of the material, calculated on a dry weight basis.

Off-farm AD materials listed in Schedules 1 and 2 may be transported by truck to the RMADF. If they are, that transportation is exempt from the approval requirements under Part V of the EPA. This exemption is applicable only if every carrier has in their possession while transporting the materials a document from the owner or operator of the RMADF that indicates the facility agrees to accept the materials.

Storage of Materials Requirements

Off-farm AD materials can be stored at a farm unit where an agricultural operation is carried out, before treatment in an RMADF, only if the rules described below are followed.

(Note: Off-farm materials must only be stored on the property where the facility is located.)

  1. No more than 200 cu. m of off-farm AD materials can be stored at any one time. Farm feed is not included in this restriction.
  2. Off-farm AD materials, not including farm feed, must be stored in the following conditions, depending upon the dry matter content:
    • If dry matter content is less than 18 per cent, store it in a sealed tank.
    • If it is stored for more than 48 hours prior to use, and if the material has a dry matter content of between 18 per cent and 50 per cent, store it in an enclosed storage facility.
    • If storing for more than 30 days prior to use and the material has a dry matter content of more than 50 per cent, store it in a facility entirely covered by a roof attached to the walls, with walls that enclose at least 75 per cent of the area of the facility.
  3. Farm feed (as defined in the regulation - see above) with a dry matter content of 18 per cent or more must be stored with a cover that will prevent it from coming into contact with any precipitation.
  4. Schedule 2 materials must be stored in a facility that was designed by an engineer to minimize odour emissions. The facility must also have been built to meet those design specifications.
  5. Any run-off is to be contained in a way that meets the current run-off requirements set out in O. Reg. 267/03.

Structural and Siting Requirements

If storage facilities for off-farm AD materials are constructed or expanded after July 26, 2007, they must meet the standards in Part VIII, Siting and Construction Standards of O. Reg. 267/03. A digester that is not performing a storage function is not deemed to be a storage facility.

An RMADF cannot be constructed or expanded on a farm unit where an agricultural operation is carried out unless a professional engineer:

  • designs the construction or expansion by following the requirements of O. Reg. 267/03
  • designs the facility to minimize odour emissions when materials are transferred into the storage facility, and when they are transferred from the storage facility into the mixed AD facility (if materials listed in Schedule 2 will be treated at the facility)
  • ensures the facility is designed to manage non-combusted biogas
  • signs a commitment certificate prepared as specified by the OMAFRA Director, stating the engineer will undertake to meet those requirements and to inspect the construction or expansion on completion.

As of January 1, 2014, all facilities require a sign to be posted and visible from the road stating the facility is an RMADF. The sign must include the contact information for the facility operator.

New facilities that are at non-livestock farm operations are subject to setback distances - 200 metres to the nearest dwelling and 450 metres from the nearest residential area or properties for commercial, community or institutional use. RMADFs located at livestock facilities are subject to the municipality's Minimum Distance Separation bylaws.

Construction or expansion of a facility must be designed to minimize noise, leakage and corrosion, and be structurally safe and sound. Any sampling port for liquids must be installed using specifically designed gasketed fittings, and have primary and secondary shut-off valves. Existing facilities with a nutrient management strategy approved prior to October 25, 2013, must install primary and secondary shut-off valves and pressure relief monitoring by July 1, 2016.

Requirements for Treatment Processes

Other than the exceptions set out in O. Reg. 267/03 (section 98.9, subsection 2 and 3), the average time AD materials must be treated in an RMADF is at least 20 days, at a minimum of 35 °C at all times.

The time can be reduced if:

  • a professional engineer designs the facility so that it is able to remove at least 50 per cent of total volatile solids of the materials in the facility in fewer than 20 days
  • the facility is built to the engineer's design specifications
  • the average time the AD materials are treated is at least as long as the time specified by the professional engineer

The temperature can be reduced if:

  • a professional engineer designs the facility so that it is able to remove at least 50 per cent of total volatile solids of the materials in the facility at a temperature lower than 35 °C
  • the facility is built to the engineer's design specifications
  • the average temperature the AD materials are treated is no less than that specified by the engineer

Off-farm AD material listed in Schedule 2 must be treated for at least one hour at no less than 70 °C, or at least 20 hours at no less than 50 °C. These materials prior to treatment must be small enough to pass through a screen where the largest opening has an area of 2.5 cm2.

Materials listed in paragraph 4 of Schedule 2 must not have been removed from the facility where the waste water is treated more than 10 days before it is received at the agricultural operation. Also, these materials must be transferred using a means that minimizes odour emissions if an offensive odour would otherwise be detectable beyond the farm unit where the materials are received.

Each facility must have a device to monitor the actual temperature at which the materials are being treated. Further, the device should be regularly monitored to ensure that it is measuring the temperature accurately.

If the off-farm AD material listed in Schedule 2 is heat treated elsewhere, the heat treatment requirements listed above are the same. A statement from a professional engineer indicating that the off-site system is capable of performing this treatment is required.

Requirements for Generated Biogas

The RMADF must be able to collect and manage all the biogas produced. The gas combustion system must be able to consume 110 per cent of the biogas that the facility can produce. For facilities designed to generate biogas at a rate not exceeding 50 cubic metres per hour (m³/hour), a secondary gas burning facility must be available that will start working within 48 hours if the rate of release of non-combusted biogas is greater than 20 m3/h.

If the facility is designed to generate biogas at a rate that exceeds 50 m³/hour, and over 25 per cent off-farm materials are being received under an approved nutrient management strategy, a secondary gas burning facility (such as a flare):

  • must be available
  • must be located on the farm unit at all times
  • must be used to prevent any release of non-combusted biogas

A secondary gas burning facility must be available if the RMADF has a nutrient management strategy approved prior to October 25, 2013, that permits up to 25 per cent off-farm materials, and the RMADF is designed to generate biogas at a rate that exceeds 50 m3/hr. The secondary facility does not have to be located on the farm unit, but it must be used within 48 hours if the rate of release of non-combusted biogas exceeds 20 m³/hour.

Gas storage covers installed after October 25, 2013, require the design permeability to be less than 500 cm3/m2/day/bar.

If the facility is designed to generate biogas at a rate that exceeds 50 m³/hr, it must have a device for monitoring if the pressure relief device is open. If the nutrient management strategy for the facility was approved prior to October 25, 2013, this pressure relief monitoring device must be installed before July 1, 2016.

Requirements for Storage of Anaerobic Digestion Output

AD materials cannot be treated in an RMADF unless the farm unit where the facility is located is able to store all of the AD output produced by the treatment during a period of 240 days. O. Reg. 267/03 includes some exceptions to this 240-day storage rule. This storage requirement is in addition to the storage capacity requirements for the farm unit that are set out in section 69 of O. Reg. 267/03.

Equipment used to apply digestate to fields as a nutrient source for growing crops. This equipment injects material into the soil profile, thus maximizing the nitrogen value of the digestate.

Figure 2. Equipment used to apply digestate to fields as a nutrient source for growing crops. This equipment injects material into the soil profile, thus maximizing the nitrogen value of the digestate. 

Requirements for Record Keeping

Every owner or operator of an agricultural operation with an RMADF must keep the following records for at least two (2) years from the day on which the nutrient management strategy stops being in force.

  1. The professional engineer's design specifications
  2. For every delivery of off-farm AD material:
    • The name and address of the generator
    • The name and address of the hauler
    • The types and volumes of materials received
  3. Results of metal analyses
  4. Results of anaerobic digestion output analyses
  5. Destinations of AD output
  6. The date(s) of use, if ever, of a secondary gas combustion system and the length of time it was used

Additional record-keeping requirements are set out in section 98.13 of O. Reg. 267/03.

Section 5: Land Application of Anaerobic Digestion Output

AD output is considered an agricultural source material:

  1. if the materials were treated in a mixed AD facility (that is, a facility that treats both on-farm anaerobic digestion materials and off-farm anaerobic digestion materials on a farm), and
  2. if at least 50 per cent, by volume, of the materials were on-farm AD materials

If AD output that falls within the definition of agricultural source material is going to be applied, the following must be met:

  • Meet every requirement in Part VI of O. Reg. 267/03 that governs land application of agricultural source materials, prescribed materials or nutrients.
  • Not apply this material to land within 150 m of the top of the bank of surface water if the maximum sustained slope of the land is 25 per cent or greater.
  • Not use a high trajectory irrigation gun capable of spraying liquid more than 10 m unless the output is an aqueous solution or suspension containing more than 99 per cent water by weight.
  • If direct flow land application systems are used, the requirements of section 50 in O. Reg. 267/03 for non-agricultural source materials will apply to anaerobic digestion output.

These rules apply to all agricultural operations, whether or not the farm unit on which the operation is carried out is required to have a nutrient management plan.

Application of Anaerobic Digestion Outputs that are not from a Regulated Mixed Anaerobic Digestion Facility

If the output is from a mixed AD facility that is not an RMADF, the nutrient management plan for the farm unit must be followed in order to apply AD output on the farm unit's land.

If a farm unit is not required to have a nutrient management plan, land application of AD output on the farm unit's land must be in accordance with the following rules:

  1. During any consecutive five-year period, the application rate must be such that the total available phosphate, per hectare, from all prescribed materials applied to land must not exceed the greater of:
    • crop production requirements per hectare for the five years plus 85 kilograms (kg) of phosphate per hectare, or
    • the phosphate removed from the land per hectare in the harvested portion of the crop during the five-year period plus 390 kg of phosphate per hectare
  2. During any 12-month period, the application rate occurs at such a rate that the total plant-available nitrogen from all prescribed materials applied to land must not exceed 200 kg of plant-available nitrogen per hectare.

Total plant-available nitrogen is the sum of:

(ammonia and ammonium nitrogen) + (nitrite and nitrate nitrogen) + (0.3) (organic nitrogen), where: organic nitrogen = total Kjeldahl nitrogen - (ammonia and ammonium nitrogen)

Section 6: Lists of Off Farm Materials

O. Reg. 267/03 has three schedules. Schedule 1 lists materials that may be accepted at an agricultural operation for treatment in an RMADF. Schedule 2 lists materials that may be accepted subject to the restrictions set out in O.Reg 267/03. Schedule 3 lists materials that cannot be accepted.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: Don Hilborn - Engineer, Byproducts and Manure/OMAFRA; Mohsen Keyvani - Senior Program Support Coordinator/MOE
Creation Date: 19 August 2011
Last Reviewed: 16 June 2015