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Waste Treatment Best Available Techniques (BAT)

The BAT conclusions for waste treatment were published in August 2018 after several years of work across Europe. We lost almost two years of progress due to Covid and our cyberattack and we are now starting the review process.

Our aim is to complete all reviews by end March 2023.

Who is in the sector?

The Waste Treatment BRef covers a wide range of activities including:

  • Biological treatment such as composting and anaerobic digestion
  • Treatment in shredders of metal waste
  • Treatment of waste oil and oily wastes such as drilling mud
  • Physico-chemical treatment of waste

The full list can be found in the BAT conclusions.

Process and Timetable

Early October 2022 SEPA will issue Further Information Notices asking operators to carry out a gap analysis of their activities using a spreadsheet, comparing them against the conclusions and identifying where they are already meeting the standard, where this either is not being met at the moment, or will not be able to be met. Interpretational guidance has also been prepared to clarify particular issues.
4 December 2022 Closing date for completed gap analysis to be completed. Operators return the completed spreadsheet by the date specified in the information notice.
Dec- Feb 2023 SEPA will assess the information provided and compare it against each BAT conclusion to determine compliance. We may have further discussion with operators to clarify any issues arising.
End March 2023

Following a review there are three potential outcomes:

  1. There is no change needed to the permit
  2. The permit is varied to ensure it complies with the regulations and reflects BAT. This will be a SEPA initiated variation which has no charge. Sites have a right to appeal.
  3. Enforcement action taken where the permit holder cannot comply with the permit or BAT

Contacts and links for further information

SEPA Waste Treatment Interpretational Guidance 

Example Gap Analysis Spreadsheet. For reference only. Please contact SEPA if you need a copy of the spreadsheet.’ and ‘Guidance to complete the spreadsheet can be found on the first tab.

Information sessions presentation: Waste Treatment BAT Conclusions Permit Reviews.

Further information or guidance

Process FAQs

A gap analysis spreadsheet has been e-mailed to each site along with a Further Information Notice. If you have not received the spreadsheet or have difficulty accessing the spreadsheet please e-mail

If you don’t think the Waste Treatment BREF review applies to your primary activity, then please email

you should send your completed gap analysis spreadsheet and any supporting evidence or information to by 4 December 2022 at the latest.

Please email any questions to We will make sure the appropriate person answers your query which may be your site officer or a technical expert. Using the mailbox will help us understand and address common questions and identify any issues. It will also ensure you receive a consistent answer.

Please ensure all documentation is clearly named and linked to a BAT condition. Large files can be shared via SharePoint. To request a link, you should contact

Please refer to the guidance tab on the gap analysis spreadsheet to check what supporting evidence is required.


We are working to a tight timescale and would appreciate your cooperation in meeting the submission deadline of 4 December 2022. Our aim is to complete the reviews by the end of March 2023. This is a priority in SEPA’s Annual Operating Plan and a commitment to Scottish Government. It is therefore unlikely that we will be able to grant an extension. We are trying to make the process as easy as possible but do appreciate the volume of work to be undertaken varies depending on the site and activities. We want to engage with operators and provide as much support as possible. If you are having difficulties meeting the submission date, please email as soon as possible.

Please tell us about your current operations and also tell us where the gaps are. We may use upgrade conditions for any information that cannot be collated before 4 December 2022, e.g., a delay caused by the need for a third-party contractor. SEPA wishes to be flexible and work with the operators. If you are having difficulties meeting the submission date, please email as soon as possible.

The waste treatment BREF reviews are one of a number of activities due for review under the Industrial Emissions Directive. The impact of COVID and the significant cyberattack on SEPA in December 2020 have delayed SEPA’s progress on reviews across all activity areas. We are working with the Scottish Government to prioritise the work based on the legislative timetable and available resource.

Since it is a SEPA initiated variation, you will not be charged for the review.

If the change is related to a BAT conclusion this should be discussed with SEPA. If it is unrelated, e.g. to increase the amount or types of waste that can be accepted, this must be done as an operator-initiated variation. There is a charge for this.

Probably not but we would like to understand the timescales involved with the surrender and the particular circumstances.

Supporting information can be supplied in separate documents but please make sure each supporting document is referenced in the relevant part of the spreadsheet and this reference aligns to the supporting document name.

We are organising our resources to meet the end of March 2023 deadline. We have a Leadership Team in place focusing on ongoing BREF reviews and we are setting up a focused team working offline specifically to assess the waste treatment reviews and carry out any required variations. We are looking to streamline this process as much as possible which starts with good quality gap analysis information. SEPA has a commitment to complete the waste treatment BREF reviews by the end of March 2023 in our Annual Operating Plan and with the Scottish Government.

SEPA assesses compliance against the current permit. If your permit is varied following the BREF review, then SEPA will only assess compliance against the new conditions once they have taken effect. SEPA is not expecting full compliance with the BAT conclusions by 31 March 2023 and where necessary longer timescales can be agreed.

This issue is being looked at internally. For the purposes of the gap analysis, we need to know the difference between the current discharge and the BAT conclusions. Please submit your current monitoring results and any gaps. Once we have this information, we will have a better idea of the nature and scale of the situation. SEPA will take a view on these BAT conclusions once we have a better understanding of the overall situation for the sector.

SEPA is involved in discussions with the Environment Agency and the Wood Recyclers Association to take this issue forward. Correctly stored demolition wood is unlikely to result in soil or groundwater pollution. SEPA does not anticipate that demolition timber will cause a significant problem for the purposes of the BREF reviews.

If you think you need a derogation, please contact as soon as possible. Any derogation requests will be considered in accordance with SEPA’s Guidance on Appraising a Request for Derogation (IED-TG-44 Regulation 25(12) – Derogation from BAT-AEL). Further information is available on SEPA’s website: Derogation from BAT-AEL (

SEPA is aware that some anaerobic digestion and in-vessel composting activities are permitted under s6.8 rather than s5.4 of the Pollution Prevention and Control (Scotland) Regulations 2012. The waste treatment BREF reviews do not apply to activities permitted under s6.8 and operators of these sites do not need to complete a waste treatment BAT gap analysis at this stage. SEPA is developing a plan to permit these activities under s5.4 and ensure the operations meet the waste treatment BAT conclusions. Further details and timescales will be confirmed and communicated with the affected operators in the coming weeks.

The reasons we need the information to be resubmitted include:

  • The officer carrying out the review may not be aware of the site operations and previous performance; and they may not have access to the working file held in the office.
  • We may not have access to the electronic information following the cyberattack on SEPA.
  • The information previously submitted may be out of date, e.g., management plans may be updated annually, or more recent monitoring results may be available.