New regulations will help control air pollution from combustion plants

Two new sets of regulations which will control a major source of air pollution which could harm human health will be the subject of new permitting requirements.

The Medium Combustion Plant Directive (MCPD) sets out rules to control emissions of sulphur dioxide (SO2), nitrogen oxides (NOx) and dust into the air, while the Specified Generator regulations will also control emission to air, primarily NOx, from generators that would not be captured by the MCPD.

Medium combustion plants that are also specified generators must comply with both requirements.

Claire Watts, Industry Regulation advisor for Natural Resources Wales, explained:

“A Medium Combustion Plant (MCP) is any plant or equipment used to burn (combust) materials, including waste, with a rated thermal input between one and 50 megawatts.

“Specified generators are any combustion plant used to generate electricity with a rated thermal input of less than 50 megawatts.

“These regulations apply to certain waste and industrial processes, but also to various premises such as hotels, supermarkets, prisons, schools and office blocks, places NRW, as the regulator, doesn’t normally deal with.”

From 20 December 2018, new MCPs will require a permit and have to comply with Emission Limit Values (ELVs) from the date of permit issue. Certain specified generators will also require a permit and have to comply with Emission Limit Values (ELVs) from 1st January 2019.

Claire said:

“These regulations will play a major role in protecting people and the environment by reducing the amount of pollutants in the air.

“The introduction of MCPD for new plants is just the start, further permit requirements for existing MCPs and other specified generators will be introduced in the future.

“You can find out if you require a permit by visiting the NRW website, where permit application forms and technical guidance is available at

For general enquiries about medium combustion plant or specified generator activities, send us an email at

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