The graphic titled “Installation and pipeline pathways” is a flowchart showing the decision-making and approval process for offshore decommissioning under the North Sea Transition Authority (NSTA).

At the top, the overall aim is stated as “Aim to achieve a clear seabed.”

The diagram then splits into two main pathways based on whether full removal of an installation is possible:

1. Installation full removal pathway

  • The process begins with the decision: “Installation full removal?”
  • If yes, a draft decommissioning programme is prepared for installations under 10,000 tonnes (all topsides).
  • This progresses through:
    • Public consultation
    • Decommissioning programme (DP) submission
    • DP approval
  • Following approval, the process continues with:
    • DP execution, reporting and monitoring
    • Close-out report and post-decommissioning monitoring
    • Management of liability and legacy of remaining infrastructure

2. Derogation or alternative decommissioning pathway

If full removal is not possible:

  • The process asks whether an installation derogation from OSPAR 98/3 applies.
  • If applicable, a comparative assessment (complex) is undertaken, supported by:
    • Environmental appraisal (EA), studies and evidence
  • A preferred option is identified, followed by:
    • Draft decommissioning programme
    • Public consultation and OSPAR consultation
    • Submission for approval alongside the main DP process

3. Pipeline and related infrastructure pathway

If the case relates to pipelines and associated items:

  • Options include full removal or “leave in situ”
  • The process includes:
    • Decommissioning option screening (using comparative assessment criteria)
    • Comparative assessment (non-complex)
    • Risk and consequence assessment
  • A preferred option is selected and follows:
    • Draft decommissioning programme
    • Public consultation
    • Submission into the wider DP approval process

Additional notes

  • Several points in the process are marked with a red star indicating:

    Consultation with NSTA under section 29(2A) of the Act

  • The flowchart emphasises:
    • Regulatory compliance (OSPAR 98/3)
    • Evidence-based decision making
    • Stakeholder consultation
    • Lifecycle oversight from planning through to post-decommissioning monitoring