What to do before you apply for a standalone Medium Combustion Plant (MCP) less than 50 MW thermal input that is also a Specified Generator (SG) or Part B activity

If you need to apply for a standalone MCP between 1 and less than 20 MW thermal input that is not a Specified Generator, see What to do before you apply for a standalone medium combustion plant permit between 1 and less than 20 MW thermal input

You must provide the following information with your permit application:

• Air quality modelling assessments screening (using the SCAIL Combustion screening tool)
• Whether or not your MCP / SG is located within Air Quality Management Area (AQMA)
• Non-technical summary
• Confirmation that you have a management system in place
• Evidence to show your ability as a permit holder (the operator)
• A Best Available Techniques (BAT) assessment for Part B activities

Air quality modelling assessment screening (using the SCAIL Combustion screening tool)

You will need to complete the SCAIL Combustion screening tool to determine whether the air emissions from your MCP / SG are a risk to human health receptors and protected habitat sites close to your MCP / SG. These include Ramsar sites, Sites of Special Scientific Interest (SSSI), Special Areas of Conservation (SAC), Special Protection Areas (SPA) and Marine Conservation Zones.

To use the SCAIL Combustion screening tool, you need specialist knowledge of air quality assessment and dispersion modelling so you may need to use a consultant to complete this for you. This may take a few weeks to complete, so you will need to complete that before making your application.

You can find a consultant in ENDS Directory. They will charge for their services.

You or your consultant will need to use the screening distances in the table below and input those into the SCAIL combustion screening tool to enable it to identify any protected habitat sites close to your MCP / SG. The screening distances will depend on the size and fuel type of your MCP / SG. 

If your MCP is also a Specified Generator you will need to manually input human health receptor locations into the SCAIL Combustion screening tool.

If your MCP / SG can meet 'new' MCP Emission Limit Values (ELV) set out on pages 16 and 17 of the relevant table of Annex II of the Medium Combustion Plant Directive (MCPD), you can input these values into the SCAIL combustion screening tool to demonstrate a low risk impact to the environment.

If you voluntarily declare that your MCP / SG can meet the 'new' MCP Emission Limit Values (ELV) we will include those limits in your permit which you will need to comply with from 1 January 2025.

You can voluntarily declare that your MCP / SG can meet these limits in your application form. 

If you do not declare that your MCP can meet the ‘new’ MCP Emission Limit Values (ELV), we will include ‘existing’ plant limits (relevant to your MCP) in your permit which you will need to comply with from 1 January 2025.

Minimum screening distances to the habitat sites

The SCAIL combustion screening tool

The SCAIL Combustion screening tool is available on the Centre for Ecology and Hydrology (CEH) website which is used by all UK Regulators for the assessment of boiler, engines, generators and turbines.

Use the SCAIL tool on Centre for Ecology and Hydrology (CEH) website

There is a general SCAIL Combustion user guide available on the CEH website to help you complete the tool.

We have our own SCAIL Combustion screening tool user guide that explains how to use the tool, how to assess the results, and how to present the results with your permit application.

The SCAIL combustion screening tool will either 'screen out' or 'screen in' your MCP / SG.

If your MCP / SG 'screens out' using the SCAIL combustion screening tool, you do not need to carry out any air quality modelling assessments, but you will need to complete the SCAIL results template and submit that with your permit application.

If your MCP 'screens in' using the SCAIL combustion screening tool, you will need to carry out a site-specific air quality modelling assessment that assesses the risks to human health and protected habitats close to your MCP / SG and submit that with your permit application.

Air quality modelling assessments requires specialist knowledge so you will need to use an environmental consultant to do this for you. This may take a few weeks to complete, so you may wish to do that before making your application.

You can find a consultant in ENDS Directory. They will charge for their services.

Please contact Natural Resources Wales if you want to do your own detailed modelling.

You must ensure your MCP / SG air emissions do not breach an air quality standard and therefore you must assess against these standards in your risk assessment.

As a result of your air quality modelling assessment, we may set stricter permit conditions such as those that require you to:

• meet a lower Emission Limit Value (ELV)
• better disperse emissions
• reduce hours of operation

You must meet these conditions from the date the permit is required.

Further information on how to carry out an appropriate risk assessment can be found on Gov.uk

MCP / SGs located within an Air Quality Management Area (AQMA)

If your MCP / SG is located within an Air Quality Management Area (AQMA) you must provide:

• Details of the AQMA

• Actuals emissions from your MCP

Find out if you are in an Air Quality Management Area on the DEFRA website

We will consult the Local Authority to check if your MCP is identified in the associated Air Quality Management Plan and if it is, your MCP emissions may be identified as adversely impacting air quality in the area.

The local authority, in its plan, will identify how much stricter the Emission Limit Values (ELVs) needs to be to deliver a noticeable improvement to air quality. We will include the agreed stricter ELVs in your permit conditions.

Non-technical summary

You will need to provide a summary that explains your application, in non-technical language as much as possible, avoiding technical terms, detailed data and scientific discussion.  This should include a summary of the site and a summary of the key technical standards and control measures arising from your risk assessment.

If your application is for a mobile plant you must tell us how the activities you want to carry out could impact land quality, describe the mobility of your plant and how you intend to operate. 

Confirmation that you have a management system in place

 You must have an effective, written management system in place that identifies and reduces the risk of pollution. You may show this by using a certified scheme or your own system. Your permit requires you (as the 'operator') to ensure that you manage and operate your activities in accordance with a written management system.

You can find guidance on management systems on the GOV.UK web-page ‘Develop a management system: environmental permits’.

You will be asked to confirm you have read the guidance and your management system meets our requirements in the application form.

Evidence to show your ability as a permit holder (the operator)

When determining your application we must consider whether you will be a competent permit holder ('operator'). We will look at your technical ability and whether you have been convicted of a relevant offence. A relevant offence is one relating to the environment or environmental regulation.

We will also check to see if you have been declared bankrupt or insolvent and can check your financial standing by way of a credit check. We will also check that you have a management system in place.

A Best Available Techniques (BAT) assessment

You will need to provide a BAT assessment with your permit application if your MCP / SG is:

• A boiler, furnace, gas turbine or compression ignition engine AND is individually equal to or greater than 20 MW thermal input
• Burns 50 kg or more per hour of waste biomass

 You may wish to use a suitably qualified environmental consultant to carry out a Best Available Techniques (BAT) assessment for you, so you will need to complete that before making your application.

You can find a consultant in ENDS Directory. They’ll charge for their services.

Boilers, furnaces, gas turbines or compression ignition engines individually equal to or greater than 20 MW thermal input

Your MCP / SG is also subject to Schedule 1, Section 1.1 Part B of the Environmental Permitting Regulations and we will therefore include additional conditions in your permit.

We will send you a draft copy of your permit for review before it is issued.

Your BAT assessment will need to be completed in line with this 1.1 Part B Environmental Permitting technical guidance note on the gov.uk website and submitted with your application. 

MCPs that burn 50 kg or more per hour of waste biomass

You will need to submit a Best Available Techniques (BAT) assessment if your MCP / SG burns 50 kg or more per hour of the following types of waste biomass:

• vegetable waste from agriculture and forestry;
• vegetable waste from the food processing industry, if the heat generated is recovered;
• fibrous vegetable waste from virgin pulp production and from production of paper from pulp, if it is co-incinerated at the place of production and the heat generated is recovered;
• cork waste;
• wood waste with the exception of wood waste which may contain halogenated organic compounds or heavy metals as a result of treatment with wood preservatives or coating and which includes, in particular, such wood waste originating from construction and demolition waste 

If your MCP burns 50 kg or more of the waste biomass described above, this means it is also subject to Schedule 1, Section 5.1 Part B of the Environmental Permitting Regulations and therefore we will include additional conditions in your permit. We will send you a draft copy of your permit for review before it is issued.

If your MCP burns more than 3 tonnes per hour or waste not described above, please contact mcpd.queries@cyfoethnaturiolcymru.gov.uk and we will advise accordingly.

Your BAT assessment will need to be completed in line with this 5.1 Part B Environmental Permitting technical guidance note on the gov.uk webpage and submitted with your application.

Energy efficiency report for MCPs equal to or greater than 20 MW thermal input

You may need to provide an energy efficiency report if the total aggregated net thermal input of your MCP / SGs is 20 MW thermal input or more.

You may also wish to use a suitably qualified environmental consultant to carry out the report for you, so you will need to complete that before making your application.

You can find a consultant in ENDS Directory. They will charge for their services.

If the MCP’s total aggregated net thermal input is 20 MW thermal input or more and produces waste heat at a useful temperature you must also meet the requirements of Schedule 24 of the environmental permitting regulations.

The total aggregated net thermal input means the total of the net rated thermal inputs of all the individual combustion units operated on the same site.

You must prepare and submit a report with your permit application if your MCP is:

• new or substantially refurbished
• operates more than 1,500 hours per year
• is over 20 MW thermal input (total aggregated net thermal input)
• a boiler, furnace, gas turbine or compression ignition engine

This requirement does not apply to:

• Spark ignition engines
• Existing Tranche A and Tranche B Specified Generators

Further guidance on how to meet the energy efficiency standards can be found on gov.uk.