Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, pursuant to the Answer of 11 December 2020 to Question 124345 on Incinerators: Air Pollution, what assessment he has made of the potential merits of requiring environmental permits for incinerators in England to set specific limits for (a) PM10 and (b) PM2.5 emissions rather than for total particulate matter.

In England, all large incinerators, also known as energy from waste (EfW) plants, are regulated by the Environment Agency (EA) and must comply with strict emission limits set by the Industrial Emissions Directive (as amended under the EU Withdrawal Act 2018). Permits are not issued if the proposed plant will have unacceptable impacts on human health or the environment.

Emission limits within permits are set for total particulate matter (TPM), which includes both PM10 and PM2.5. New permit applications are assessed to ensure that impacts from both types of particulate matter will be acceptable by assuming worst-case scenarios, whereby TPM is made up entirely of either PM10 or PM2.5. This allows the EA to determine the potential impact from each of these pollutants were they to make up the entirety of the TPM emitted. This is a precautionary approach as in practice TPM will be a mixture of sizes, and so the true impact will be less. The EA has not carried out a formal assessment with regards to setting limits for emissions of PM10 and PM2.5 individually because the TPM approach delivers effective control of both PM10 and PM2.5 emissions.

The EA takes into account the existing concentration of particulate matter in the areas surrounding EfW plants when setting TPM emission limits. The EA assesses new EfW plant permit applications using air quality modelling to predict the worst-case scenario for the concentration of particulates arising from the plant for both PM10 and PM2.5. This concentration is then added to the existing (background) concentration to determine the total predicted environmental concentration, which is then compared against the relevant air quality standard. If impacts from the EfW plant could cause an air quality standard to be exceeded, then a lower limit for total particulate matter could be specified in the permit, or the permit may be refused.

Finally, on the potential merits of live emissions data monitoring for EfW plants; all EfW plants in England are already required to continuously monitor emissions of oxides of nitrogen, total particulate matter, carbon monoxide, total organic carbon, sulphur dioxide and hydrogen chloride. Some are also required to continuously monitor ammonia.

Operators are required to report the results from monitoring to the EA every 3 months, and to submit annual reports of their emissions to the EA’s Pollution Inventory. The EA also carries out regular inspections and audits to ensure plants comply with their permits.