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  • Anaerobic digestion of biowaste up to 100 tonnes

Anaerobic digestion of biowaste up to 100 tonnes

This activity applies to the anaerobic digestion of less than, or equal to, 100 tonnes of biowaste per day.

‘Treatment’, for the purposes of this activity, is defined as: chipping, shredding, cutting, pulverising, blending, screening and anaerobically digesting.

The treatment of non-waste feedstocks by anaerobic digestion was introduced by EASR in 2025. However, sites do not require to have an authorisation until 1 April 2028. We are currently working on the forms, guidance and authorisation conditions and these will be made available as soon as possible.

Authorisation level

Registration

Fit and Proper Person tests

Fit and Proper Person tests apply to this activity. You will be asked in your application if you have any relevant convictions held by you or any additional persons.

Read more about Fit and Proper Person tests

Fees and charges

An application fee applies to the application of a new authorisation for this activity.

An annual activity fee applies to this activity.

Read our charging information for further information on application and annual activity fees.

Information on the application fees to transfer, vary or surrender a registration that authorises this activity, is in our charging information.

Standard conditions

Your registration application will only be granted if you can confirm you are able to comply with the standard conditions set out below.

If you carry out an activity under a registration authorisation you must comply with the standard conditions. It is an offence if you do not comply with the conditions.

SEPA will not authorise this activity if it poses an unacceptable risk to the environment.

If you cannot comply with these standard conditions, but still want to carry out anaerobic digestion of biowaste, you may be authorised to do so with a permit.

  1. The Authorised Person must regularly carry out a review of the management system and its effectiveness in terms of achieving compliance with the conditions of the authorisation.

  2. The Authorised Person must have a written management system in place to ensure compliance with the conditions of this authorisation.

  3. Only the waste types listed in Table 1 can be accepted at the Authorised Place.

    Table 1. Waste codes for anaerobic digestion

    Waste Code Authorised Wastes
    02 01 01 Sludges from washing and cleaning – vegetables, fruit and other crops
    02 01 02 Animal tissue waste
    02 01 03 Plant-tissue waste
    02 01 06 Animal faeces, urine and manure (including spoiled straw)
    02 01 07 Wastes from forestry
    02 01 99 Straw, wood or paper–based bedding waste, slurry or dirty water from stables, zoos, animal parks or livestock markets
    02 02 01 Sludges from washing and cleaning, peeling, centrifuging and separation
    02 02 02 Animal-tissue waste
    02 02 03 Materials unsuitable for consumption or processing
    02 02 04 Sludges from on-site effluent treatment
    02 03 01 Sludges from washing, cleaning, peeling, centrifuging and separation
    02 03 04 Materials unsuitable for consumption or processing
    02 03 05 Sludges from on-site effluent treatment
    02 04 01 Soils from washing and cleaning beet
    02 04 03 Sludges from on-site effluent treatment
    02 05 01 Materials unsuitable for consumption or processing
    02 05 02 Sludges from on-site effluent treatment
    02 06 01 Materials unsuitable for consumption or processing
    02 06 03 Sludges from on-site effluent treatment
    02 07 01 Wastes from washing, cleaning and mechanical reduction or raw materials used in the production of beverages (except coffee, tea and cocoa)
    02 07 02 Wastes from spirits distillation
    02 07 04 Materials unsuitable for consumption or processing
    02 07 05 Sludges from on-site effluent treatment
    03 01 01 Waste bark and cork
    03 01 05 Sawdust, shavings, cuttings, wood
    03 03 01 Waste bark and wood
    04 02 10 Organic matter from natural products (e.g. grease, wax)
    07 01 08 Glycerol waste from bio-diesel manufacture from non-waste vegetable oils
    15 01 01 Paper and cardboard packaging
    15 01 02 Compostable or digestible plastics only
    15 01 03 Wooden packaging
    15 01 05 Compostable or digestible composite packaging only
    15 02 03 Absorbents, filter materials and cloths made from compostable material only
    16 10 02 Untreated wash waters from cleaning fruit and vegetables on farm only
    16 10 02 Milk and dairy waste milk from agricultural premises only
    16 10 02 Liquor and leachate from a composting process
    19 01 18

    Biochar produced from the pyrolysis of the following waste codes:

    02 01 03 - untreated plant tissue waste from agriculture, horticulture and forestry activities

    02 01 07 - untreated wood waste from forestry activities

    02 03 04 - vegetable waste unsuitable for consumption or processing

    03 01 01 - untreated waste bark and cork

    03 01 05 - untreated sawdust, wood shavings and wood cuttings

    03 03 01 - untreated waste bark and wood

    19 02 06

    Sludge from waste types within this table which have been previously heat treated only

    19 02 10 Non-hazardous Glycerol
    19 06 03 Liquor from anaerobic treatment of municipal waste (from a process that treats wastes listed in this table)
    19 06 04 Digestate from anaerobic treatment of municipal waste (from a process that treats wastes listed in this table)
    19 06 05 Liquor from anaerobic treatment of animal and vegetable wastes
    19 06 06 Digestate from anaerobic treatment of animal and vegetable wastes
    19 08 05 Sewage sludge
    19 08 09 Grease and oil mixture from oil and water separation containing only edible oils and fats
    19 08 12 Sludges from the biological treatment of industrial waste water (from a process that treats wastes listed in this table)
    20 01 01 Paper and cardboard
    20 01 08 Biodegradable kitchen and canteen waste
    20 01 25 Edible oils and fats
    20 02 01 Biodegradable waste
    20 03 01 Separately collected biodegradable wastes
    20 03 02 Biodegradable waste from markets
  4. All waste accepted at the Authorised Place must be inspected to ensure it meets the types and quantities authorised.

  5. Wastes with the following characteristics must not be accepted at the Authorised Place:

    1. waste significantly contaminated with non-compostable or digestible materials.
    2. waste containing post-consumer wood, treated wood, wood-preserving agents or other biocides.
    3. waste containing Japanese Knotweed or any other invasive non-native plant species.
    4. pest infested waste.
  6. All potentially odorous materials must be stored within suitable closed containers or covered to prevent odour.

  7. All storage and processing of feedstock, digestate and effluent must take place on an area with a sealed drainage system.

  8. All liquid feedstock, digestate and effluent must be kept within a liquid storage and management system.

  9. The liquid storage and management system must be designed, constructed, maintained, managed and of sufficient capacity to prevent any emissions.

  10. The liquid storage and management system must be constructed as detailed in the liquid storage and management system engineering plans.

  11. Liquid digestate storage lagoons with walls made of earth must not be filled to a level that results in less than 750 millimetres of freeboard.

  12. Liquid feedstock, digestate and effluent storage lagoons with walls made of earth must:

    1. be lined with an impermeable sheet material; and
    2. have suitable leak detection
  13. The impermeable liner at the mixing and filling zones of any earth-banked liquid feedstock, digestate or effluent storage lagoons must be protected with a layer of concrete.

  14. Liquid digestate storage tank(s) must not be filled to a level that results in less than 300 millimetres of freeboard.

  15. Non-liquid feedstock must not overtop the height of the vessel it is stored in.

  16. Any gas engine and/or combined heat and power (CHP) plant stack height associated with the authorised activities must be:

    1. greater than or equal to 3 metres above the roof ridge height of the building on which it is located; or
    2. greater than or equal to 3 metres above the ground if it is located separate to any building; and
    3. greater than or equal to the height of any part of a building which is located within a distance of 5 times the uncorrected stack height.
  17. All biogas condensate must be:

    1. collected and contained; or
    2. recirculated back to the digester.
  18. Pressure, temperature and flowrate in the pressure system must be monitored and recorded via telemetry 24 hours a day.

  19. The pressure relief and vacuum systems must be:

    1. Inspected to ensure they are correctly seated; and
    2. Linked to an alarm system(s) which is connected to 24 hour telemetry.
  20. All reasonable steps must be taken to minimise:

    1. Emissions of unburned biogas;
    2. Any activation of a pressure relief valve; and
    3. The operation of the auxiliary flare.
  21. Any activation of the flare must be recorded and reported as an environmental event.

  22. All releases to the air from the authorised activities during normal operation, other than condensed water vapour, must be free from visible emissions.

  23. Point source emissions to air from the authorised activities must only be made from the gas engine and/or the combined heat and power (CHP) plant stack(s).

  24. Emissions of substance(s) to the air from the gas engine and/or CHP plant stack(s) must not exceed the specified emission limit value specified in Table 2.

  25. Air must not be added to dilute emissions in order to achieve emission limit values specified in Table 2.

  26. The emission of any substance, not specified in Table 2, from the authorised activities must not cause environmental harm.

    Table 2. Emissions to air from gas engine and/or CHP

    Substance Emission Limit Value
    Dust 50 mg/m3
    Oxides of Nitrogen (NOx) 190 mg/m3
    Sulphur Dioxide 15 mg/m3
    Total Volatile Organic Compounds 20 mg/m3
    Carbon Monoxide 1,000mg/m3
  27. Monitoring of emissions of substances to air must be undertaken at the gas engine and/or CHP plant stack(s) at the sample port, frequency and using the monitoring standard specified in Table 3.

  28. Sample points must be installed, maintained and appropriately identified so that representative samples may be safely obtained.

  29. Monitoring must be undertaken:

    1. during normal operation;
    2. under stable conditions; and
    3. at a representative, even load.
  30. The first monitoring of emissions must be undertaken within four months of the start of operations.

    Table 3. Monitoring requirements for emissions to air from gas engine and/or CHP

    Parameter Emission Point Reference Monitoring Frequency Monitoring Standard
    Dust Sample port determined in accordance with BS EN 15259 Manufacturer’s guarantee or annually BS EN 13284-1
    Oxides of Nitrogen (NOx) Sample port determined in accordance with BS EN 15259 Annually BS EN 14792
    Sulphur Dioxide Sample port determined in accordance with BS EN 15259 On commissioning of new plant OR a new feedstock is introduced to the process BS EN 14791
    Total Volatile Organic Compounds Sample port determined in accordance with BS EN 15259 Annually BS EN 12619
    Carbon Monoxide Sample port determined in accordance with BS EN 15259 Annually BS EN 15058
  31. Measures must be taken to prevent, or where that is not practicable, minimise:

    1. odour;
    2. noise;
    3. dust;
    4. litter; and
    5. the presence of vermin;

    arising from the authorised activities.

  32. Offensive odours from the authorised activities as perceived by a SEPA Officer must not be emitted beyond the boundary of the Authorised Place.

  33. Noise from the authorised activities, which has a significant impact on the environment, people or property, must not be emitted beyond the boundary of the Authorised Place.

  34. Dust from the authorised activities, which has a significant impact on the environment, people or property, must not be emitted beyond the boundary of the Authorised Place.

  35. Litter from the authorised activities, which has a significant impact on the environment, people or property, must not be emitted beyond the boundary of the Authorised Place.

  36. Waste must not be burned at the Authorised Place.

  37. SEPA must be notified via its pollution hotline contact telephone number as soon as reasonably practicable, and in any case within 24 hours of identification of an event, of any of the following:

    1. an event that has caused or could cause adverse impact to the environment or harm to human health;
    2. an event that results, or could result, in an emission to the environment that is not authorised;
    3. an event that has caused a breach of a condition of this authorisation.

    In this condition, the meaning of ‘event’ is as defined in the Interpretation of Terms of this authorisation.

  38. All measures that are reasonably practicable must be taken to stop an event and to minimise its effect on the environment.

  39. Within 14 days of an event a report must be submitted to SEPA detailing:

    1. The reason(s) for the event;
    2. the action(s) taken to stop the event and minimise the impacts; and
    3. the action(s) taken to prevent the event from recurring.
  40. All information recorded, kept or submitted to SEPA in accordance with a condition of this authorisation must be:

    1. true and accurate;
    2. kept for a minimum of six years; and
    3. provided to SEPA upon request.
  41. For each calendar year the information detailed in Appendix 1 must be submitted to SEPA on or before 28 January the following year.

  42. The information detailed in Appendix 1 must be submitted to SEPA via email, in the excel spreadsheet supplied by SEPA, to waste.data@sepa.org.uk

  43. The results of the monitoring of emissions, as described in condition 27, must be submitted to SEPA within eight weeks of the date the monitoring took place via email to registry@sepa.org.uk

How to apply

In this section you can find out how to apply for a new authorisation and how to apply for a variation, transfer and surrender of an existing authorisation.

New applications

You can apply for a new registration for this activity using our digital application service.

Step 1: Download your activity form

You will need to download and complete the following activity form. The completed form will be submitted as part of your application:

Step 2: Provide supporting information

For a new registration, you will also need to provide the following supporting information:

  • Location plan(s)
  • Information on the previous and current use of the area
  • Infrastructure plan
  • Information on your proposed waste acceptance process
  • Information on your waste storage
  • Information on your process(es) for waste treatment
  • Information on your proposed pollution control measures

Step 3: Submit using our digital application service

You can submit your completed application using our digital application service.

Make an application for a new authorisation

You can apply to vary an existing registration for this activity. Please note, this is the same activity form as applying for a new registration or transferring an existing one.

Step 1: Download your activity form

You will need to download and complete the following activity form. The completed form will be submitted as part of your application:

  • R-WAS-D1 - Anaerobic digestion of biowaste

Step 2: Submit your application for a variation

Make an application to vary an authorisation

You can apply to transfer an existing registration for this activity. Please note, this is the same activity form as applying for a new registration or varying an existing one.

Step 1: Download your activity form

You will need to download and complete the following activity form. The completed form will be submitted as part of your application:

  • R-WAS-D1 - Anaerobic digestion of biowaste

Step 2: Submit your application

Read Transfer an existing authorisation to find out how to submit your application for a transfer.

To apply to surrender an existing registration that authorises this activity, read Surrender an existing authorisation

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