CRU Report on Entry of Non-odourised Gas to the Transmission Network in September 2017

CRU Report on Entry of Non-odourised Gas to the Transmission Network in September 2017

The CRU has published a report “Entry of Non-odourised Gas to the Transmission Network in September 2017”. This report details the CRU’s investigation and follow-up enforcement actions around the event that occurred at Bellanaboy Bridge Gas Terminal on September 21, 2017.

The CRU’s mission is to regulate water, energy and energy safety in the public interest. CRU is responsible for the safety regulation of natural gas transmission and distribution, and the regulation of upstream designated petroleum activities.  

On September 21, 2017, an event occurred at the Bellanaboy Bridge Gas Terminal in Co. Mayo, which led to non-odourised gas being exported to Gas Networks Ireland’s (GNI) gas network, contrary to normal operating procedures. There was no additional risk of a gas escape as a result of this incident, however, as the gas was not odourised it would not have been possible to detect an escape by smell in the event that one occurred. As a result, and as part of the response to the incident, approximately 10,000 natural gas customers in the Galway-Mayo region were instructed by GNI to turn their gas off. 

The non-odourisation was identified by Shell E&P Ireland (SEPIL) as part of normal checks at the Terminal, at 02.30 on the morning of the 21st September. GNI were immediately alerted to the issue and the Natural Gas Emergency Plan (NGEP) was activated at 07.00. CRU formed part of this group. All affected gas was directed back to the terminal and flared off, in order to remove the non-odourised gas from the system.  

The incident occurred during a re-start process of the Terminal, following a planned maintenance shutdown, where upgrades to the IT systems were carried out. The IT upgrades caused the odourant injection system to default to a mode where there was no injection of odourant. The operating procedure covering the start-up process did not include a step requiring the operator to reset the odourant system to inject odourant.   

CRU carried out its investigation into the incident. On completion of the investigation, enforcement actions were taken by the CRU against both SEPIL and GNI.  

The investigation into SEPIL’s role in the gas incident found that the deficiencies in their operating procedures led to the incident.  There were no safety consequences as a result of this incident for personnel working at the Bellanaboy Bridge Gas Terminal or the public in the immediate vicinity. CRU directed SEPIL and partners to submit an Improvement Plan to address issues identified with operating procedures. The remedial actions set out in that Improvement Plan have been put in place and the SEPIL enforcement action is now closed.  

In relation to GNI’s role, it is the responsibility of GNI, as the gas networks operator, to transport odourised gas to customers. Following the incident, CRU carried out an investigation to determine GNI’s compliance with its accepted Safety Case as it relates to odourant injection and found some deficiencies. As a result the CRU issued GNI with an Improvement Notice to address the risk of non-odourised gas entering the GNI network. Under the Improvement submissions Notice, GNI were required to complete two actions by July 1st 2018 and a third action by December 31st 2019. GNI provided submissions for the initial two actions ahead of the July deadline.  Evaluation of these and monitoring of the remaining action is ongoing.    

A full copy of the report into the event can be found here



The CRU has responsibility for the safety regulation of natural gas transmission and distribution and the regulation of upstream designated petroleum activities. Specifically, the Electricity Regulation Act, 1999, gives the CRU responsibilities in the areas of electrical, gas and petroleum safety. In relation to this issue, it includes the following functions:

  • Regulation of the activities of natural gas undertakings and LPG safety licence holders with respect to safety
  • Regulation of the activities of natural gas and LPG installers with respect to safety
  • Promotion of the safety of natural gas and LPG customers and the public generally regarding the safe use of gas

As one of the primary agencies overseeing the use of natural gas, the CRU are part of the National Gas Emergency Plan (NGEP) response group and also monitor the safety procedures for the distribution of gas.

  • A petroleum undertaking means a person to whom a petroleum authorisation has been given or granted. SEPIL and their partners, Equinor Energy Ireland Limited and Vermillion Energy Ireland Limited are the petroleum undertakings for the production activity at the Bellanaboy Bridge Gas Terminal.  
  • A gas undertaking is a person engaged in the transmission, distribution, supply or storage of natural gas, including any holder of a licence or a consent under the Electricity Regulation Act 1999 (as amended), or any person who has been granted a licence or given a consent under the Gas Acts, 1976 to 2002. 
  • Undertakings must have their safety management systems (Safety Cases) accepted by CRU in order to carry our certain activities. Safety cases are in place for the operation of the gas network by GNI and the carrying out of the gas production activity by SEPIL and its partners via the Terminal. CRU check SEPIL’s and GNI’s compliance with their respective Safety Cases through regular audits and inspections.
  • Where CRU deem it necessary, it can take enforcement action against the undertakings where non-compliances have been identified. The applicable legislation includes a number of different enforcement options that are progressive in nature. This enables CRU to make a determination on a case by case basis as to the appropriate enforcement action to take in the interests of safety. 
  • An Improvement Plan is a type of enforcement action whereby the CRU requires the undertaking to submit a plan to CRU for its acceptance. The plan must set out how the undertaking will return its activity to a state of compliance and must include timescales. CRU will assess the plan and will accept it where the proposal and timelines are acceptable. Non-compliance with an improvement plan is not an offence but can result in escalation of the enforcement action to an improvement notice. 
  • An Improvement Notice is a type of enforcement action whereby the CRU directs an undertaking to return its activity to a state of compliance. It is an offence not to comply with an improvement notice which can result in significant fines on indictment. In accordance with the legislation, an Improvement Notice must be preceded by an Intent to Issue an Improvement Notice at least 21 days in advance of issuance of the Improvement Notice. Undertakings are given the opportunity to make representations to CRU during this period.