Mossmorran Complex investigation update February 2019

Service status

A sophisticated criminal cyber-attack has had a major impact on the way SEPA works. We are working through all the services that we provide to understand what we need to do in the short and longer term to restore services. We are approaching this work with a sense of urgency.

Mossmorran Complex investigation update February 2019

SEPA has completed its investigation into a number of unplanned flaring events at the Mossmorran Complex during 2017 and 2018.

Whilst flaring is an important safety mechanism and is permitted through permit conditions, the impact of any flaring events must be mitigated so as not to have an unacceptable impact on local communities.

SEPA remains clear that the flaring in June 2017 was both preventable and unacceptable and Final Warning Letters were issued to ExxonMobil Chemical Ltd and Shell UK Ltd in that regard. Communities experienced further unplanned flaring in October 2017, March 2018 and again in May 2018.

In August 2018, SEPA announced an investigation into ExxonMobil Chemical Ltd and Shell UK Limited. SEPA also announced a review of, then served, operating permit variations on both operators to strengthen noise and vibration controls whilst the investigation was underway.

With a firm focus on ensuring stringent compliance and mitigating the impacts of flaring, SEPA has concluded that robust enforcement action taken is currently appropriate and effective. The environmental performance of ExxonMobil Chemical Ltd and Shell UK Ltd will be kept under review and SEPA will not hesitate to take further action in line with its Enforcement Policy if appropriate.

This update summarises the range of enforcement action that SEPA has taken, sets out what will happen next, and explains how SEPA will continue to liaise with communities.

Enforcement actions and environmental monitoring

  • Permit variations were served on both operators requiring ExxonMobil Chemical Ltd and Shell UK Ltd to ensure they take all appropriate preventative measures against noise and vibration emissions through the application of ‘Best Available Techniques (BAT)’ and ensure that no significant pollution is caused.
  • The environmental performance of ExxonMobil Chemical Ltd and Shell UK Ltd will be kept under review and SEPA will not hesitate to take further action in line with its Enforcement Policy if appropriate.

Summary of flaring events

Flaring event

Incident length

Impacts noted


Operators involved

 June 2017

Approximately 5.5 days

 Noise and vibration


Mechanical failure of a steam condensate return pump.



Flaring for approximately 1.25 days including

26 minutes

27 minutes



Black smoke

Black smoke




Lack of steam supply to the flare.

Loss of ethane feed causing rapid reduction in steam header pressure.






October 2017

3.25 days

Noise and vibration

Ethylene release from a flange.


March 2018

Approximately three days

Noise and vibration

Shut-down of a process gas compressor by a safety mechanism.


 May 2018


Approximately four days

Noise and vibration

Splitter product draw-off pump outage.



Final Warning Letters

Final Warning Letters were served on both companies by SEPA in April 2018 related to “preventable and unacceptable” unplanned flaring during June 2017. Both can be viewed on SEPA’s website.

Variation of permit conditions and evaluation of Best Available Techniques (BAT)

Notices of variations to their Permits were served on ExxonMobil Chemical Limited and Shell UK Limited in June 2018.

The variations included the requirement to complete an evaluation of the Best Available Techniques (BAT) to prevent and, where that is not practicable, reduce emissions of noise, vibration and smoke associated with flaring.

The outcome of the BAT assessment is an essential part of understanding what can be done to stop unacceptable and preventable impacts of flaring.

SEPA has held review meetings at key stages with both companies to ensure progress. The interim reports on progress towards the evaluation of Best Available Techniques for flaring, which were required by 30 November 2018, have been submitted and are available to view on SEPA’s Public Register.

They indicate that the Operators are progressing towards completion by the required date of the 30 April 2019 and that the scope of the assessment covers the appropriate breadth and depth.

  • ExxonMobil Chemical Limited and Shell UK Limited have confirmed that five separate working groups have been established incorporating technical specialists from both operators and third party consultants to cover the full scope of the assessment.
  • Progress to date has highlighted potential ground flare technologies and site based techniques that may reduce and/or minimise noise, vibration and/or smoke from flaring. The companies have advised that further assessment is required to determine what combination results in the best overall benefit.
  • In addition to publishing the interim reports SEPA is committed to publishing the Operators’ final assessments.

Both operators must continue their commitment to implementing Best Available Techniques. SEPA will continue to work with Exxonmobil Chemical Limited and Shell UK Limited to provide advice and guidance if required, and will ensure any proposals are acceptable and appropriate. If this is not the case we will take any necessary action.

SEPA believes it is important that operators continue to explore opportunities for good communication links with local communities.

Investigations by SEPA and HSE

The Mossmorran Complex falls under the Control of Major Accident Hazards (COMAH) Regulations. These are enforced by the COMAH Competent Authority, represented by the relevant safety body (for Mossmorran this is the Health and Safety Executive) and the appropriate environmental regulator (SEPA).

SEPA’s focus is to ensure compliance in terms of the ability for the Installation to flare safely without causing unacceptable impact on the local community.

SEPA’s Enforcement Policy sets out the intent and principles underpinning our approach to enforcement action. The intent behind the enforcement action we have taken is to:

  • secure compliance and change the behaviour;
  • stop or reduce the risk of harm arising from the non-compliance to an acceptable level.

SEPA has used our enforcement policy to guide our decisions in taking what we consider to be the most appropriate and effective actions at this time in order to secure compliance.

In this instance the mechanism for compliance should be identified via the BAT assessment and both Operators have provided interim reports indicating that a suitable final assessment will be delivered.

If further events occur that show negligence and/or repeated root causes, further action can be taken to secure compliance.

Under COMAH SEPA and the HSE co-ordinate the approach as the Competent Authority. SEPA focuses on the environmental aspects of incidents, although there is often an overlap with safety aspects considered under COMAH by the HSE.

Further information on COMAH is available on the Health and Safety Executive website.

Monitoring programme

SEPA has undertaken air quality monitoring in the vicinity of the Mossmorran Complex. Following a consultation with community representatives, through the Mossmorran and Braefoot Bay Community Safety Liaison Committee, a trailer has been located at the farm to the North East of the complex and diffusion tubes will be placed in community locations.

SEPA Update on Environmental Monitoring Proposals in the vicinity of the Mossmorran Complex - as shared with the Mossmorran and Braefoot Bay Community Safety Liaison Committee

Information is being shared with the Independent Air Quality Review Group (including community representatives), Fife Council, NHS Fife and Health Protection Scotland.

A forward programme for environmental monitoring is being discussed with the Operators and partner organisations.

Communicating with communities

SEPA has worked within the limitations of communicating during a live regulatory investigation to keep local communities informed through:

  • Mossmorran Communities Working Group

Co-chaired by Lesley Laird MP for Kirkcaldy and Cowdenbeath and Professor Wilson Sibbett from the University of St Andrews, the Mossmorran Communities Working Group allows elected members, community representatives, regulators and operators to discuss community-related issues and find solutions to them in the short, medium and long term

These community liaison meetings are held once a quarter and are attended by local councillors, representatives from local community councils, SEPA, ExxonMobil Chemical Limited, Shell UK and Fife Council. The minutes of the meetings should be made publically available to members of local communities through community council meetings, local libraries and the Fife Direct webpage.

The Mossmorran and Braefoot Bay Independent Air Quality Monitoring (IAQM) Review Group is independently chaired by Professor Sibbett of St Andrews University. Members are appointed by Fife Council and include representatives from Fife Health Board, SEPA, Fife Council, the Institute of Occupational Medicine and community representatives. The Group meets twice per year and publishes an annual report which is available from the Fife Direct webpage.

The group advises Fife Council regarding the quality of ambient air associated with air emissions from operations at the Mossmorran plants and the Braefoot Bay terminal facilities. The Review Group liaises with representatives from community councils and the local health service.

Of particular relevance are issues relating to any health concerns raised by residents within the local communities and a key role is assisting with the communication of information relating to environmental air quality.

Updates are published online, as well as being proactively emailed to those who have signed up to the mailing list. Anyone who wishes sign up for the newsletter can do so at

We will continue to work to keep good lines of communications open with appropriate groups and elected representatives to explain what we are doing, hear concerns and provide reassurances where we can.

We have committed to keeping the public informed through our dedicated Mossmorran hub, and anyone with concerns or queries not related to an ongoing pollution incident can use the online contact form.

Information about a potential or ongoing pollution incident (including flaring) should go to our 24 hour pollution hotline on 0800 80 70 60 or via The earlier we know about a potential issue, and the more information we have, the better we can investigate.