EPA publishes report on leaks from ESB Networks Fluid Filled Underground Electricity Cables

Date released: Feb 26 2020

The EPA today published a report on its investigation into leaks from fluid filled underground electricity cables.  The cable leaks were highlighted in an RTE Investigates programme entitled ‘The ESB Leaks’, which was broadcast on the 5th June 2019 and repeated on the 9th January 2020. 

In preparing this report, the EPA sought detailed information from ESB Networks and consulted with:

  • the Commission for the Regulation of Utilities
  • local authorities in theareas where leaks were reported
  • Department of Communications, Climate Action and Environment
  • Department of Housing, Planning and Local Government
  • Waterways Ireland,
  • Energy Networks Association
  • Environment Agency (United Kingdom) and
  • Mr Seamus O’Loughlin (who first highlighted this issue).

The main conclusions arising from the EPA investigation are outlined below.

  • There were 68 ‘historic’ leaks between 1993 and June 2019 and a further 7 ‘current and new’ leaks since June 2019.  The locations and scale of each leak has been identified by ESB Networks and they are now undertaking site specific investigations of each.
  • The fluid used as an insulating liquid in cables was originally mineral oil and more recently linear alkyl benzene (LAB).  Mineral oil is classified as hazardous while LAB is classified as non-hazardous.  ESB have identified that the fluid lost from the cable leaks is often a mixture of mineral oil and LAB and therefore must be classified as hazardous.
  • While ESB Networks report that they consulted the relevant authority regarding 20 of the 68 leaks identified prior to June 2019, ESB Networks failed in the case of 48 leaks to notify Local Authorities, in accordance with Section 14(1) of the Local Government (Water Pollution Act) 1977, as amended; 
  • ESB Networks failed to screen the impact of fluid leaks, which occurred since 1st April 2009, for the applicability under Regulations 7 and 9 of the European Communities (Environmental Liability) Regulations 2008, as amended, until after June 2019;
  • ESB Networks have established two protocols since June 2019 to deal with historic and future leaks. TheEPA is satisfied with the approach and protocols now being implemented by ESB Networks to assess each leak and to engage with the relevant Local authorities.
  • The EPA acknowledges that decommissioning of fluid filled cables can be a challenging process. but considers fluid filled cables that have a high occurrence of leakage and are in proximity to sensitive receptors should be prioritised for decommissioning.

ESB Networks has completed a preliminary assessment of each fluid filled cable leak, these assessments have been submitted to the relavant Local Authority.  ESB Networks commenced site-specific investigations in January 2020, based on a site prioritisation plan.  The results of the site specific assessments will be submitted to the relevant Local Authorities and interested parties.  The assessments will identfy the remediation to be carried out, where necessary.   
The Investigation Report is available on the EPA website.

Notes to Editor:
Fluid filled cables were installed for the transmission of electricity until the mid-1980’s, at which point there was a transition to plastic cables which do not require a liquid insulation material.  Approximately 177km of fluid filled cables remain in service in Ireland under the control of ESB Networks.