Decommissioning – Pipelines

For information on the impact of Brexit on oil and gas environmental legislation, please refer to the pdf document downloadable from the Home Page.

Key Legislation:

For more detail on the Legislation relevant to this page, please use the following links:

Supporting Legislation

Waste Management

Guidance Notes

The Guidance Notes are intended to help companies understand their liabilities and the process for approval of decommissioning programmes. They have been updated to take account of both the experience gained since 2006 and the relevant decommissioning provisions in the Energy Act 2008. These Guidance Notes do not yet include requirements of the Marine and Coastal Access Act and Marine Scotland Acts. New BEIS Guidance is pending.

The PWA and DEPCON guidance has been moved to the OGA website, capturing the transition of DECC to BEIS in the guidance.

  • OGA Guidance: Pipeline Works Authorisations (PWA)
    • This Guidance Note offers an update to the oil and gas sector on the UK marine planning process with a focus on environmental impact assessments (EIAs) associated with decommissioning activities within a marine plan area.
  • BEIS: Guidance Note for Operators – Offshore Oil and Gas Sector: Update on Marine Planning in the UK
    • This guidance offers insight on where updated Regulations on the assessment of environmental effects apply and the requirements associated with environmental impact assessments.
  • 2020 EIA Regulations Guidance: The Offshore Oil and Gas Exploration, Production, Unloading and Storage (Environmental Impact Assessment) Regulations 2020 – A Guide. This guidance is accompanied by a template for the Environmental Statement Details to be provided upfront of the ES and an EIA summary of Project template to be provided to OPRED as part of the EIA submission pack. The Guidance and templates can be downloaded from the UK Government’s website.

Notification of Disused Pipelines Form

  • The Disused Pipeline Notification (DPN) Form required when taking pipeline(s) out of use is currently being updated by BEIS. A copy can be made available on request at


Consent Needed: Decommissioning Programme Approval of the Decommissioning Programme from the regulatory authority is required.Section 29 of the Petroleum Act 1998 enables the Secretary of State to serve notices requiring the recipient to submit a costed Decommissioning Programme for his approval at such future time as he may direct. The programme (referred to in the 1998 Act as an “abandonment programme”) should contain the measures proposed to be taken in connection with the decommissioning of a pipeline. Equivalent Notices previously served under section 1 of the 1987 Act will continue to be valid.Other Consents and Permits A Marine and Coastal Access or Marine Scotland Act Licence is required for all decommissioning operations and most operations will include a range of activities requiring licences. Operators will be able to apply for licences for individual activities, or to apply for licences to cover a range of activities.A Chemical Permit under the Offshore Chemical Regulations 2002 is also required for the use or discharge of any chemical during decommissioning.Decommissioning activity may be incorporated into existing OPEP or a decommissioning OPEP produced (see Oil Pollution Emergency Planning).If the coral Lophelia pertusa is present on an installation/pipeline located outside territorial waters that is being transported to the UK or elsewhere, a CITES certificate will be required from Defra.A Marine and Coastal Access or Marine Scotland Act Licence is required for deposit of stabilisation or protection materials related to decommissioning operations (see Decommissioning Deposits)A Wildlife Licence (see Performances Standards tab) may be required, depending on specific decommissioning activities being undertaken.Additional authorisations for radioactive related issues may be required, depending on specific decommissioning activities being undertaken (see LSA and Radioactive Waste).If there is any likelihood of oil release (reservoir hydrocarbon) during decommissioning of the pipeline, a permit under OPPC will also be required (for example see Produced Water).There are specific requirements around navigation issues under the Coast Protection Act – see Decommissioning – Navigation.Emergency Pipeline DepositsAs part of standard pipeline operations, in order to allow urgent deposits to be made in emergency situations, an ‘Open Permission – Emergency Pipeline Deposit Template’ has been generated for PWA Holders.The ‘Open Permission’ requires the PWA Holder to complete the following template and submit it to the OGA by 9am on the next working day following the emergency deposit. This needs to be submit to Claire Grant ( at the OGA.
How to Apply: Subsequent to the submission of draft copies of the Decommissioning Programme and the associated periods of consultation, six copies of the final draft copy of the Decommissioning Programme should be sent to the regulatory authority.In addition to the Decommissioning Programme, Operators must apply for new and/or vary/surrender existing permits/consents following the specific procedures for the individual permits/consents.The application process for licences under the MCAA and MSA is not yet known. BEIS guidance has been drafted and is awaiting issue.Disused Pipeline Notification – Updated BEIS requires operators to submit details of pipelines or sections of pipelines that are to be taken out of use. The disused pipelines notification has been updated to include more specific requirements on the information to be provided. The form is available on the BEIS website here.
Who to Apply to: Documents should be marked for the attention of the Head of the Offshore Decommissioning Unit and be addressed to: The Department of Business, Energy and Industrial Strategy
Atholl House
86-88 Guild Street
Aberdeen AB11 6ARIt is BEIS’s intention that applications will eventually be administered through the UK Oil Portal. In addition to the Decommissioning Unit, Operators must apply to the relevant departments/organisations for new (or variations to/surrender of existing) permits/consents.The application process for licences under the MCAA and MSA is not yet known. BEIS guidance has been drafted and is awaiting issue. Any queries in the meantime should be direct to BEIS Oil & Gas Environmental Management Team by email to 

When to Apply: See “Timing of preparation of Decommissioning Programme” under the Performance Standards tab.The application process for licences under the MCAA and MSA is not yet known.
Requirement to remove, or otherwise, pipeline:

Because of the widely different circumstances of each case, it is not possible to predict with any certainty what may be approved in respect of any class of pipeline. Each will be considered on its merits and in the light of a comparative assessment of the alternative options.

Leaving in place

As a general guide the following pipelines (inclusive of any “piggyback” lines that cannot be easily separated) may be candidates for in-situ decommissioning:

  • Those which are adequately buried or trenched and which are not subject to development of spans and likely to remain so
  • Those which were not buried or trenched at installation but which are likely to self bury over a sufficient length within a reasonable time and remain so buried
  • Those where burial or trenching of the exposed sections is undertaken to a sufficient depth and it is likely to be permanent
  • Those which are not trenched or buried but which nevertheless may still be candidates for leaving in place if demonstrated by the comparative assessment to be the preferred option (e.g. trunk lines)
  • Those where exception and unforeseen circumstances due to structural damage or deterioration or other cause, cannot be recovered safely and efficiently

Judgements regarding the degree of burial or trenching necessary will be undertaken on a case-by-case basis in the light of individual circumstances. Consultees will need to be satisfied that the pipeline is sufficiently buried or trenched below seabed level to avoid obstruction to other uses of the sea. Decisions on the appropriate depth of burial will take account of seabed conditions and other relevant factors but it is expected that burial to a minimum depth of 0.6 m above the top of the pipeline will be necessary in most cases.

Pipelines, which it is agreed can be left in place, should be cleaned, sealed and filled with water.


Small diameter pipelines, including flexible flowlines and umbilicals which are neither trenched nor buried should normally be entirely removed.

Any mattresses or grout bags which have been installed to protect pipelines during their operational life should be removed for disposal onshore. If the condition of the mattresses or grout bags is such that they cannot be removed safely or efficiently then any proposal to leave them in place must be supported by an appropriate comparative assessment of the options.

In the case of rock-dump that has been used to protect a pipeline it is recognised that removal is unlikely to be practicable. It is assumed therefore that rock-dump will remain in place, unless there are special circumstances that would warrant consideration of removal. If the rock-dump is associated with a pipeline that is being left in place then it would be expected that the rock-dump would remain undisturbed. If, however, it is associated with a pipeline that is being removed then minimum disturbance of the rock-dump to allow safe removal of the pipeline and the elimination of any seabed obstruction that may result from the presence of the rock, would be expected.


In those cases where a pipeline reaches the end of its operational life before other facilities in the field, the Operator should notify BEIS’s Offshore Decommissioning Unit that the pipeline is no longer in use. BEIS will send the Operator a Disused Pipeline Notification form requesting details on the status of the pipeline that has been taken out of use. Upon receipt of this information, BEIS, in discussion with other Government Departments (including the SEMD, DEFRA and HSE), will consider whether a Decommissioning Programme for the pipeline is appropriate at this stage or whether its final decommissioning can be dealt with at end of field life along with the other facilities in the field.

If it is agreed that final decommissioning may be delayed until a more appropriate time, BEIS will issue a letter setting out the conditions upon which it is prepared to defer formal decommissioning. This may include the requirement to carry out remedial work on the pipeline. BEIS will wish to be satisfied that leaving the pipeline in place until end of field life will not prejudice any final decommissioning solution – including complete removal – and that the pipeline will be subject to an appropriate surveying and maintenance regime.

In cases where decommissioning is deferred, the pipelines concerned are considered to form part of the Interim Pipeline Regime.

Habitats Directive and Birds Directive: BEIS is obliged to take proper account of the obligations stemming from the Birds and Habitats Directives to protect and conserve the marine environment. A number of offshore sites have been designated as draft or possible SACs (see JNCC website).Where the Secretary of State considers that there may be significant effect on the conservation objectives, they may require an Habitats Regulatory Assessment to be undertaken.If this is the case, JNCC will recommend that, as competent authority, BEIS undertakes a screening for a Habitats Regulatory Assessment (SHRA) or a full Habitas Regulatory Assessment (HRA). The ES or decommissioning operation application should contain adequate information to enable BEIS to undertake the assessment. EU Guidance on Habitats Regulatory Assessment (PDF document) can provide guidance on the process, in particular Annex 2.
Assessment of Disturbance of Marine European Protected Species: Under the Offshore Marine Conservation (Natural Habitats &c.) Regulations 2009 (as amended), a person is guilty of an offence if he:

(a) deliberately captures, injures, or kills any wild animal of a European protected species, or

(b) deliberately disturbs wild animals of any such species.

Disturbance of animals includes in particular any disturbance which is likely to:

(a) impair their ability:

  • to survive, to breed or reproduce, or to rear or nurture their young, or
  • in the case of animals of a hibernating or migratory species, to hibernate or migrate, or

(b) to affect significantly the local distribution or abundance of the species to which they belong.

The Marine European Protected Species (EPS) includes all species of cetaceans, all species of marine turtles and sturgeon.

The onus is on the developer carrying out an activity to:

  1. Assess the likelihood of committing a disturbance offence
  2. Consider the need for mitigation measures
  3. Decide whether to apply for a Wildlife Licence (See section below).

A description of the assessment of the likelihood of committing a disturbance offence must be included in the PON14A application. Guidance on undertaking such an assessment is included in the JNCC’s Protection of marine European Protected Species from injury and disturbance for England, Wales and the UK offshore marine area. This document is currently being updated by the JNCC and a link will be provided once the document is released.

Wildlife Licences: If there is a risk which cannot be removed or sufficiently reduced by the taking of mitigation measures then a Wildlife Licence may need to be granted by the regulatory authorities for a number of “purposes”. Purposes include “over-riding public interest” and “scientific and educational purposes”. Licences can however only be issued where there is no satisfactory alternative. It is expected that the majority of activities will not require a Wildlife Licence since their potential for disturbance will fall below the threshold of the office in the Regulations. More information can be obtained from the JNCC website.

Revisions to wildlife licenses effective from 1 January 2015 (England only)

Changes to general and class licence updates have been implemented after Natural England’s public consultation in 2014. From 1 January 2015, a licensee must make sure that they are operating under the conditions of these updated licences (as detailed here). 

Public Participation Directive: The Public Participation Directive (PPD) requires a number of aspects of public notification and consultation:

    • An outline of main alternatives (if any) should be included in permit applications
    • The public should be notified and made aware of any decisions making available relevant consents and permits with the reasons and considerations on which decisions have been based
    • Public notification at the earliest possible time where the information can be provided on the nature of possible decisions
    • Making available within applicable time frames the necessary reports, advice issued to the regulator in accordance with legislation when applications were made and information relevant to a decision which only became available after advertisement of an application.
Timing of Preparation of Decommissioning Programme: Discussions should commence well ahead of forecast cessation of operations. As pipelines vary significantly in size and length, BEIS advice should be sought at an early stage where the decommissioning does not form part of platform decommissioning. At a mutually agreed time, following preliminary discussions, the operator should submit to BEIS 23 copies of a first draft of a Decommissioning Programme. Copies of the draft programme will be distributed by BEIS to other Government Departments and Agencies. Submission in CD ROM form is the preferred method, although one paper copy will also be required. Four paper copies will be required when the holders of section 29 notices are directed formally to submit the Decommissioning Programme. On receipt of a first draft of a Decommissioning Programme, the Offshore Decommissioning Unit will circulate it for consideration by others with an interest within BEIS and to other Government Departments. At the same time BEIS will agree with the operator a timetable for considering the draft programme and submitting it for approval by the Secretary of State, the process taking approximately 10 weeks. The Offshore Decommissioning Unit will act as a one-stop-shop, coordinate all comments on the draft and submit a written response to the operator. Further meetings with Government Departments may be necessary at this stage to discuss whether additional information and amendments to the draft programme may be necessary. It is important that sufficient time is allowed for the proper consideration of the proposals in a Decommissioning Programme. In the majority of cases only one draft of the Decommissioning Programme will be necessary.
Consultations: At the point at which the draft Decommissioning Programme is submitted to BEIS, the Operator should commence statutory consultations as required under section 29(3) of the Petroleum Act 1998. These consultations will be with the representatives of those parties who may be affected by the decommissioning proposals such as the fishing industry. Details of the statutory consultees will be specified in a in a letter containing a notice issued under the Section 29 of the Act. A list of the parties contained in an annex to the Decommissioning Guidance Notes (see Guidance Notes under the Legislation tab). The Statutory Consultees should normally be given 30 days in which to comment.The operator will also be asked to announce its proposals by placing a public notice in appropriate national and local newspapers and journals, and to place details on the Internet. This notice should indicate where copies of the draft Decommissioning Programme can be viewed and to whom representations should be submitted. A standard Form of Notice including appropriate publications can be provided by BEIS. Hard copies of the draft programme should be made available at the Operator’s offices and a copy can be placed on the Internet. At the same time BEIS will indicate on its website that the Decommissioning Programme has been issued for consultation. The results of consultations should be reviewed with BEIS and reported in the Decommissioning Programme when it is submitted for approval. This can be best achieved by appending to the programme the correspondence with interested parties and by indicating the extent to which their views have been taken into account.
Content of the Decommissioning Programme: A Decommissioning Programme will typically contain the following sections:Section 1 – Introduction
Section 2 – Executive Summary
Section 3 – Background Information
Section 4 – Description of Items to be Decommissioned
Section 5 – Inventory of Materials
Section 6 – Removal and Disposal Options
Section 7 – Selected Removal and Disposal Option
Section 8 – Wells
Section 9 – Drill Cuttings
Section 10 – Environmental Impact Assessment
Section 11 – Interested Party Consultations
Section 12 – Costs
Section 13 – Schedule
Section 14 – Project Management and Verification
Section 15 – Debris Clearance
Section 16 – Post Decommissioning Monitoring and Maintenance
Section 17 – Supporting Studies
Section 18 – Structure of Combined Decommissioning ProgrammesWhere it is proposed that a pipeline should be decommissioned in-situ, either wholly or in part, then the Decommissioning Programme should be supported by a suitable study which addresses the degree of past and likely future burial/exposure of the pipeline and any potential effect on the marine environment and other uses of the sea. The study should include the survey history of the line with appropriate data to confirm the status of the line including the extent and depth of burial, trenching, spanning and exposure.
Treating, keeping and disposing of waste: The Environment Agency (in England and Wales) and the Scottish Environment Protection Agency (in Scotland) are responsible for administering and enforcing the waste management controls. Anyone who deposits, recovers or disposes of waste must do so in compliance with the conditions of a waste management licence, or within the terms of an exemption from licensing, and in a way which does not cause pollution of the environment or harm to human health. Any Operator planning to carry out any decommissioning or an associated activity involving waste should contact the relevant Agency. The Agencies are finalising separate guidance for industry on the treating, keeping and disposing of wastes at the decommissioning stage. This guidance will be available from the Environment Agency and the Scottish Environment Protection Agency.The disposal of materials onshore must comply with the relevant pollution prevention and waste requirements (see Handling Waste Offshore, Transfer Special/Hazardous Waste, Transfer Controlled Waste, and Waste Disposal).Movements of waste from the UKCS to other Member States and Non-Member States are deemed to be a transboundary movement and are therefore subject to transfrontier regulations (see Waste and Transhipment of Waste).
Navigation and Marking of Remains: There are specific requirements for Hydrographic Office notifications and marking of remains – see Decommissioning – Navigation.
Where the Pipeline has been Completely Removed: Upon completion of decommissioning operations, appropriate surveys should be undertaken to identify and recover any debris located on the seabed which has arisen from the decommissioning operation or from past development and production activity. The area to be covered is likely to vary from case to case but the minimum required will be a radius of 500 metres around the location of the installation or any remains Debris monitoring may be required up to 100 metres either side of a decommissioned pipeline over its whole length. Following the removal of any debris, independent verification of seabed clearance will be required. The advisability of over-trawling will be considered on a case-by-case basis and will be dependent upon the extent of any cuttings piles and any other relevant circumstances.In addition to debris surveys, a post-decommissioning environmental seabed sampling survey should be undertaken to monitor levels of hydrocarbons, heavy metals and other contaminants in sediments and biota. A survey strategy should be developed in consultation with BEIS who will in turn take advice from other Government Departments and Agencies with an interest such as the Fishery Departments. Details of the survey strategy should be included in the Decommissioning Programme.
Where Pipeline is Left Partly or Wholly in situ: In addition to the debris clearance and environmental survey requirements described above, where pipelines are left partly or wholly in situ, additional monitoring requirements will be required as described below.Pipelines decommissioned in situ will be subject to a suitable monitoring programme agreed with BEIS in consultation with other Government Departments. Details should be specified in the Decommissioning Programme. The form and duration of the monitoring programme will depend upon the prevailing circumstances and if necessary will be adapted with time.
Close Out Report: At the conclusion of decommissioning operations the Operator will be required to satisfy BEIS that the approved Decommissioning Programme has been implemented.  This will involve the submission of a close out report within four months of the completion of offshore work.  This report will include results of the debris clearance and post decommissioning surveys. The report should explain major variations from the decommissioning programme and should summarise the following:

  • Information on the outcome of the decommissioning programme as a whole.
  • An explanation of any major variances from the programme.
  • The results of debris clearance and any monitoring undertaken.  Any independent verification (e.g. seabed clearance certificates) should be attached.
  • The results of the post-decommissioning survey.  If necessary update the schedule for future monitoring or monitoring of items left in place with reasons for the changes.
  • Measures taken to manage the potential risks arising from any legacies, including participation in the Fisheries Legacy Trust Company, confirmation of marking any remains on mariners charts, inclusion in the ‘Fishsafe’ system and installation of navigational aids.
  • Provide high level summary of actual costs and a general explanation of any difference against forecast costs.

Following submission of the Close-out Report to BEIS, the Operator will be asked to place a copy on their website.

Where Pipeline is left Partly or Wholly in situ: Inspection reports (as agreed with BEIS) should be submitted to BEIS Offshore Decommissioning Unit, together with proposals for any maintenance or remedial work that may be required.
Other Reporting: In addition to the Decommissioning Programme Close Out Report, Operators must report as required by other permits/consents and legislative requirements, e.g. covering such issues as waste reporting, seabed deposits, chemical use and discharge, oil discharges, radioactive substances, oil and chemical spills, etc., following the specific procedures for the individual permits/consents and relevant legislation.
Offshore Inspection: The BEIS (then DECC) Offshore Oil and Gas Environment Unit Enforcement Policy (PDF document) sets out the general principles that Inspectors shall follow in relation to enforcement including prosecution.
Marine and Coastal Access Act and Marine (Scotland) Act: Licences will be valid for a maximum period of one year, but operators will be able to apply to renew licences that cover a range of activities.
Ongoing Monitoring and Surveys: There may be a requirement to conduct further environmental seabed surveys subsequent to the decommissioning of the pipeline.Where a pipeline has been left in situ there is a requirement to undertake a monitoring programme (see the Snippets tab).
Alignment for Decom North Sea and Oil and Gas UK UK offshore oil and gas industry trade bodies Oil & Gas UK and Decom North Sea are to align on key areas to deliver a more efficient and effective decommissioning agenda for the North Sea. More information available here.
Decommissioning Delivery Programme

This programme focuses on three key priorities:

  • Cost certainty and reduction
  • Decommissioning delivery capability
  • Decommissioning scope, guidance and stakeholder engagement.
Decommissioning workshop outputs are now available on the OGA website Decommissioning workshop outputs are now available on the OGA website. Themes include delivering capability and decommissioning scope and practice.
Growing market for Decommissioning in Norway Growing market for Decommissioning in Norway evident from Oil and Gas UK forecast (link here).
OGA Decommissioning Strategy The Oil and Gas Authority (OGA) has published its Decommissioning Strategy, the first of a series of strategies that it plans to issue.Further details are available here.
Pipeline Cleaning: Experience to date highlights the advantage of commencing cleaning operations early in the decommissioning process. In addition to cleaning hydrocarbons, reasonable endeavours to remove wax and other contaminants, particularly where a line is to be decommissioned in place, will be expected. Guidance on cleaning topsides and pipelines prior to decommissioning has been developed through the Pilot Brownfields Initiative. This is available from Oil & Gas UK.Risk Based Monitoring: Following a DECC commissioned study to determine the appropriate requirements for long term monitoring of these pipelines left in situ, it has been concluded that a risk based monitoring scheme based on pipeline stability and potential impact remains appropriate for lines which are decommissioned in place. Each pipeline must be judged on its individual burial history and condition when establishing a monitoring scheme. Inspections of pipelines should then be undertaken for a fixed period depending on the risk criteria after which time they may move to a reactive basis, i.e. surveys only if concerns arise about the pipeline.  As part of this process DECC will be closely involved with the Operator during the monitoring phase and will review the findings of reports in consultation with other Government Departments and fishermen representatives before deciding whether a reactive basis is appropriate.
Stakeholder Engagement during Decommissioning Activities: In April 2013 Oil & Gas UK produced updated guidelines for stakeholder engagement during decommissioning activities. The guidelines were first published in 2006 but have been updated to reflect experience in recent decommissioning projects.Territorial Seas:Pipelines that cross the UK seabed within the territorial sea (12 nautical miles from the UK coastline) are likely to be subject to a lease granted by The Crown Estates which will include a rental payment based upon the size of the pipeline.  Operators may apply to The Crown Estates for termination of the rent upon completion of decommissioning works or suspension of the rent if the pipeline has fallen into temporary disuse.
Updates to PWA Applications Page:

OGA has updated the PWA applications page and its guidance (link here). This includes:

  • Updating BEIS Environmental Management Team address to; and 
  • Removing irrelevant or inaccurate information and amending formatting of templates. 
  • PWA applications should provide a word and PDF copy of an application to