Medium Combustion Plant Directive (MCPD) Requirements

To comply with the requirements of the Environmental Permitting Regulations (EPR), Schedule 25 you can now apply for a permit from the Environment Agency (EA) for the following:

  • New standalone MCPs between 1-50MWth (before it is commissioned).
  • Existing standalone MCPs between 5-50MWth (must be permitted by 1st January 2024).
  • Tranche A and B specified generators (permitting date requirement varies).

Standard Rules (SR) Permit for New and Existing Low Risk Stationary MCPs

To apply for a SR permit you must be able to meet the rules set out in the permit, if you cannot you need to apply for a bespoke permit.

If you already have a permit and you now want to add some existing MCPs at the same site, then you should use the same application form as you would if applying for a new SR permit.

Bespoke Permits for Existing Standalone MCP 5-50MWth

If you cannot meet the conditions in a standard rules permit, you must apply for a bespoke permit.

There are 2 types:

  • Simple bespoke (low risk) – does not require detailed air dispersion modelling.
  • Complex bespoke (high risk) – does require detailed air dispersion modelling.

The guidance has been updated so that you can assess which type of bespoke permit you must apply for and the information you will need to provide.

The air emissions risk assessment process has been updated; breaking it down into stages. Stage 1 provides a minimum screening distance to a protected habitat, if you are operating MCP outside of these distances then you can apply for a simple bespoke permit. If you are within the Stage 1 screening distances, then you should move to a Stage 2 assessment.

If you already have a complex bespoke permit for your plant and you now want to add existing plant, you will need to make a variation application. Provided existing plant was included in the original air dispersion modelling report (ADMR) which was submitted during determination of that permit you may use this ADMR again when you apply to vary the permit providing there have been no changes, such as to fuel types with additional pollutant emission limits or increase in operating hours.

If existing plant was not included in the original ADMR and you cannot screen out using the air emissions risk assessment guidance, then you will need to submit another ADMR which does include both new and existing combustion plant. You may want to future proof this report to include all combustion plant on site – for example MCPs 1-5 MWth.

If you already have a bespoke permit for a specified generator and that plant will now need permitting as an existing MCP you will need to make an application to vary your permit. The type of application you need to make, the charge and the supporting information will vary depending on the circumstances:

  • If your permitted plant burns natural gas or gas oil it will retain the same emission limit values in the permit, this means that we will not need to reassess any air quality emissions assessments/modelling – you should make a minor variation application.
  • If the emission limit values change when you will need to provide a revised air quality modelling report.

EA Review of MCPs, Listed as part of an Industrial Emissions Directive (IED) Permit

For existing MCP between 5-50MWth which are listed as part of an Industrial Emissions Directive (IED) permit the Environment Agency (EA) will carry out a review of these permits to ensure they are MCPD compliant as a minimum.

Reviews of permits in the industrial food, drink and milk and bio-waste sectors are already underway as part of a wider review programme.

Specified Generators

The EA has published a revised specified generator tool. You can now use this tool as part of an air emissions risk assessment for a bespoke application if you operate one of the following:

  • Tranche B or Tranche A specified generator site, or a mix of Tranche A and B specified generator site where all Tranche A generators comply with the Tranche B requirements.
  • Single or group of new or existing engines that can achieve the medium combustion plant directive and, or specified generator emission limit values.
  • Specified generator or generators that have vertical stacks without cowls or caps.
  • Specified generator or generators that are fuelled by natural gas or are fuelled by ultra-low sulphur diesel with secondary abatement, used for balancing and aggregated to no more than 20MWth.

Monitoring and Reporting

The periodicity of monitoring and report are shown in the permit and should include: site name, medium combustion plant type (e.g. Boiler), thermal input rating (MWth), permit number and date of permit. Your test results should include:

DateHours RunFuel TypeFuel Used (litres/kWh)Emissions Checks Carried OutSO2 Value (mg/Nm3)NO2 Value (mg/Nm3)Dust Value (mg/Nm3)CO Value (mg/Nm3)Signature










You will also require Environmental Permit Management System Manual detailing the considerations and operational details that are relevant to the operation of a medium combustion plant (MCP) and minimise the risks of pollution of, so far as is reasonably practicable. It should detail the nature of the site, relevant site and infrastructure works, methods of operation and environmental controls.

MCPD Compliance Support from 2EA

2EA can support your organisation with all aspects of Medium Combustion Plant Directive compliance, from initial assessment through to ongoing reporting. We help you identify in-scope plant, manage registration and permitting, and ensure you meet emission limit values and regulatory deadlines. Our team works closely with you to simplify complex requirements and deliver a clear, practical route to compliance, reducing risk and minimising disruption to your operations. Please feel free to contact us for more information.

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