22/06/2026
Personal Statement, Michael Wright – Failure to reduce Major Accident Risk to ALARP in the vicinity of the hamlet of Monboddo. (𝐴𝑠 𝐿𝑜𝑤 𝐴𝑠 𝑅𝑒𝑎𝑠𝑜𝑛𝑎𝑏𝑙𝑦 𝑃𝑟𝑎𝑐𝑡𝑖𝑐𝑎𝑏𝑙𝑒)
I am a 25 year+ HSE professional, responsible for managing Major Accident Hazards (MAH) and in reviewing Environmental Impact Assessments.
During my career I previously have been involved with the construction of several 48” HP MAH Gas transmission pipelines, on behalf of National Grid namely:
• Aberdeen to Lochside
• Bathgate to Newarthill
• Felindre to Tirley
During those projects I attended numerous public consultation events on behalf of National Grid; one of the concerns of the public that came up often was the risk of explosion. It was explained to them that due to the high-pressure nature of the pipeline, there was little risk of explosion due to the gas/air mix unlikely to reach an ignitable ratio until approximately 50m in the air, and with no source of ignition there was no means to cause ignition of the gas.
The proposed TKUP OHL must cross several MAH pipelines along its route and with proposed pylon heights of 50m to 70m, this introduces a source of ignition for the operational lifetime of the OHL, at the height where in the event of a breach the gas/air mix would have reached an ignitable ratio, representing a new Major Accident Hazard introduced.
In additional to the more general legislative safety requirements, under the Pipeline Safety Regs and COMAH Regs there is a legal duty to reduce the risk of major accident to ALARP.
With regards OHL crossing the MAH pipelines, several risk factors increase the likelihood of a major accident during the operational life of the OHL, increasing exposure to the Major Accident Risk and/or increasing the likelihood of AC corrosion:
• Proximity for extended distances
• Parallel course between the OHL and MAH pipeline
• Oblique crossings of the MAH pipeline, increasing exposure to the risk and increased potential for AC corrosion.
• Sudden changes in pipeline direction
The main risk factors that increase the consequences of a major accident are:
• Proximity of residential properties to the MAH pipeline and OHL interaction
• Concentration of residential properties in proximity of the MAH pipeline and OHL
interaction
Other factors may also increase the risk of a major accident:
• Damage to the pipeline coating during construction or farming excavations,
increasing the risk of AC corrosion.
• A direct breach of the pipeline because of working the farmland.
Where the current proposed route passes by the settlement of Monboddo, the route selection has failed to minimise the above risk factors increasing the potential for a major accident.
In the routing of the OHL in close proximity to Monboddo, it does not appear that SSEN have considered the Major Accident Risk of the OHL interacting with the MAH pipelines during their operational life and met their regulatory requirement to reduce risk of Major Accident to ALARP.
The failure to reduce Major Accident Risk for the operational OHL on the D4 route section is clear as the route not only fails to minimise exposure to the MAH pipeline near, but it also fails to minimise consequence by crossing the MAH pipeline at the greatest concentration of properties outside of the villages of Auchenblae and Fordoun, the residential community of Monboddo.
SSEN know the risks associated with MAH pipeline crossings and are quick to direct concerned community members to their guidance document for pipeline crossings (Pathway to 2030 – Tower Crossing Considerations, May 2024).
However, the planned crossing at Monboddo fails to comply with SSEN’s own guidance for pipeline crossings (Pathway to 2030 – Tower Crossing
Considerations, May 2024), crossing at an extremely shallow angle rather than at 90-degrees as per guidance and near a high concentration of residential properties.
There is no doubt that this crossing represents a Major Accident Risk for the operational life of the OHL, with the introduction of the OHL as an ignition source for an accidental release from the High-Pressure MAH Pipeline. Due to the positioning of the pylons, there is potential to damage the pipeline coating during construction and due to the nature of the land use as sublet farmland there is the potential for farming activities to also cause accidental damage to the coating. A
damaged coating combined with the potential for AC corrosion increases the likelihood of a corrosion related breach. Additionally, again due to the nature of the land use, the potential for an accidental breach due to farming excavations though the operational life of the OHL cannot be discounted.
The potential for a release, could have severe consequences due to the number of residential properties in the vicinity (closest properties lie approximately 150m from the crossing). Based on the UKOPA Good Practice Guide – Pipeline Hazard Distances (UKOPA/GP/016 Edition 1, April 2018) the initial hazard distance, due to a release igniting, would impact between 14 and 17 residential properties, potentially resulting in multiple fatalities. My own house is one of the
closest and I fear in the event of a release home and my family would likely be within the more severe blast areas.
Aside from route options not disclosed to the public (including their original route, prior to the moving of the proposed substation from Fiddes to Fetteresso) bySSEN the alternative D5, route corridor has been stated by SSEN as being economically similar in cost to the D4 route corridor and technically feasible.
The D5 route would potentially involve crossing a second pipeline, however, following the hierarchy of control, the alignment of the OHL could be engineered to cross the pipelines at 90 degrees or as close to as possible, (as per SSEN’s own guidance), reducing the potential for AC induced corrosion, reducing the risk exposure and therefore, the probability of a major accident and by locating the crossings as far from as many residential properties possible, reducing the
potential consequence.
This reduction in the likelihood and in potential consequences, presented by the D5 Route corridor, represents reducing the Major Accident Risk to ALARP.
With the alternative D5 route corridor (not including any other route options not taken forward by SSEN, likely due to fears of greater public objection from the village of Auchenblae) lowering the risk of the Section D pipeline crossings to ALARP, SSEN have failed to comply with their legislative requirements to reduce Major Accident Risk to ALARP when selecting the D4 option and the HP
MAH Pipeline crossing at Monboddo.
The minimum I would expect to see in relation to this specific crossing is:
• A Management of Change process undertaken with regards the introduction of
TKUP OHL as a Major Accident Hazard.
• A MAH Risk Assessment that has been carried out with the introduction of the TKUP OHL, demonstrating the achievement of ALARP.
• Emergency modelling associated with the ignition of a breach at the crossing.
• Demonstration of ALARP, compared to other options.
This issue is clear and apparent, as demonstrated by National Gas’s initial objection to the associated Fetteresso (Hurlie) Substation, which has only been removed on condition that any OHL must only cross the existing MAH pipelines at a 90-degree angle.
In the past in Scotland, we moved a music festival due to the perceived risk of an oil pipeline below the site and SSENs original OHL and Fiddes substation has been moved due to the presence of a run-down house of a long dead author. Yet where there is a Major Accident Risk associated with the operational OHL, a route has been selected that fails to meet the legal obligations to manage that risk to ALARP.
I ask the reporters to seriously consider the safety of the residents of Monboddo, and request SSEN reconsider this routing to ensure that any MAH pipeline crossings are in accordance with their own guidelines and meet their legal responsibility to reduce the risk to ALARP.