The Inland Waterways Association of Ireland (IWAI) is a voluntary organisation and registered charity, founded in 1954 to protect Ireland’s navigable rivers and canals. We represent over 3,000 waterways users with 23 branches across the Island of Ireland.

The main focus of our organisation is to promote the restoration, development and wider use of Ireland’s 1,000 Km navigable waterway network.

The organisation, through a corps of dedicated volunteers, has worked on a number of large-scale canal and waterway restoration projects, including the Royal Canal restoration, a project that extended over a period of decades until full restoration was finally achieved in 2012.

IWAI is currently involved in restoration projects on the Boyne navigation and the Newry canal. We are also involved in a joint venture restoration of the ‘Dunrovin’ site at Coosan Point on Lough Ree with RNLI. The restored building will function as a base for RNLI search and rescue facilities on Lough Ree and will also provide a HQ building for IWAI nationally.


This issue paper has been prepared by IWAI Dublin branch and focuses on a series of pollution incidents that impacted on a large number of sites around the Dublin area that have been traced back to 1993 and involved the release of some 500,000 litres of pollutants into the environment.  Some 12% of material released related to sites that were classified as ‘sensitive’ as they were immediately adjacent to the Grand Canal and hence is of concern to waterway users.

The Grand Canal cable leaks controversy dates from June 2019, when serious allegations regarding pollution of the waterway were levelled at ESB Networks by whistle-blower Seamus O’Loughlin. These allegations initially surfaced as part of a current affairs programme ‘RTE Investigates’ and lead to hearings conducted by the Oireachtas Joint Committee on Communications, Climate Action and Environment in July of that year.

Subsequently, in February 2020, EPA published the findings of an in-depth investigation into pollution from ESB underground cables in the Dublin area over a period of several decades.

In advance of considering the main findings by EPA the following excerpt from Seamus O’Loughlin’s evidence to the  Oireachtas committee provides useful background:

“With regard to fluid-filled cables, ESB Networks has approximately 120 km of high voltage cables which use a mixture of fluids as an insulating medium. As per the agreed PR3 submission to the regulator, they contain 300,000 l of oil. The annual leakage rate over the past 20 years averaged 50,000 l per annum. That is a leakage rate of 17%; in the worst years it ran at 30%. UK utilities using similar cables have a leakage rate of approximately 2% annually”.

“ESB is an associate member of the UK based Energy Networks Association, which provides expert guidance on dealing with fluid-filled cable leaks. The average leakage rate of 50,000 l compares poorly against the ESB Networks policy target of 15,000 l per annum. In 2017, five cable circuits were shown to have an environmental risk rating of nine and were all non-compliant with both the UK and ESB standards”.

“The PR4 submission to the regulator by ESB Networks referred to environmental risk 23 times. Although the replacement fluid is biodegradable, 90% of the fluid employed by the ESB contains some element of mineral oil, and the internal ESB guidance is quite clear that ESB Networks is obliged by law to design out and manage the environmental risk posed by leakage from fluid-filled cables on its network. It is my understanding that leakage detection and minimisation performance have improved since I submitted protected disclosure No. 1 in January 2019″.


Following these initial revelations, which were widely reported in the media, and a series of hearings conducted by the Oireachtas committee (see below), the matter was referred to the Environmental Protection Agency which undertook a detailed investigation. This Report was published in February 2020.

In the section following, we provide a summary of the findings of the EPA investigation as it relates to the volume and location of leakages.

68 incidents of leakage are detailed in the report over the period 1993-2019. In an appendix to the report the volume associated with each leak is indicated. Precise locations aren’t provided – there’s a reference only to the specific circuit where a break occurred, eg ‘Poolbeg-Harold’s Cross’.

All of the leaks were in the Dublin area, with the exception of four reported in Cork city.

From Appendix 4, IWAI has derived a total leak volume of 523,000 litres. The average leak volume is some 8,000L. However, there are large variances in leak volumes, with the most significant incident dating from 2000 and resulting in 126,000 litres of material entering the environment. The leak wasn’t repaired until 2003 and on its own accounts for almost 25% of overall volume of pollutants. This is almost unprecedented in it’s scale as a single incident of industrial pollution in the Dublin region but unaccountably the report is silent on both the environmental impact of this exceptional pollution incident and even fails to reveal its locale.

EPA have categorised leaks on the basis of whether they occurred pre or post 2009. This relates to the fact that, post 2009, pollution incidents were subject to more onerous reporting and management arrangements under environmental regulations introduced at that time.

In addition to the detail in Appendix 4, a summary of leak volumes per year from 2007 is included as Table 1.2 in the main body of the report. To complicate matters,, two sets of figures are presented in this table. The first set is derived from internal ESB management figures and the second is data as provided by ESB to EPA in September 2019. The former figure totals at 315,000L and the latter at 187,000. A massive anomaly which is presented without explanation or comment!

If we exclude the data for 2007 & 2008 we can derive a cross reference statistic against the post-2009 total provided in Appendix 4:

Appendix 4 post 2009 leakage total: 187,000L

Table 1.2 post 2009 leakage total : 315,000L or 223,000L (depending on source whether internal ESB or as reported to EPA).

Because EPA’s presentation of the data in appendix 4 isn’t actually totalled, we cannot readily state whether they are aware of this very significant data disparity.

The map reproduced above is included in the EPA report and is intended to provide a locational reference with respect to leakage incidents around Dublin city.  Underground cable routes are highlighted along with reference numbers that are drawn from elsewhere in the report. In theory inspection of the map will allow specific locations to be correlated with details such as leakage volume.

Unfortunately, however, the map isn’t scalable which makes it impossible to identify leak locations precisely. IWAI raised this as an issue with EPA, but they referred us back to ESB. EPA also stated that the purpose of the map was solely to provide very generalised locations. This is not very helpful as a response from the agency charged with fully investigating the overall impact of leaks that were widely dispersed around the city and often resulted in large volumes of pollutants being emitted over a period of many decades.


However, map deficiencies notwithstanding, the report does highlight leaks linked with locations along the Grand Canal.

This is a core issue of concern to users of the inland waterways and was one of the main issues raised by the ESB whistle-blower when he appeared on the RTE Investigates programme.

The EPA report documents a total of 5 ‘sensitive’ leaks along the canal, with the earliest dating to 1993 and the most recent occurring in 2018.

The leaks resulted in release of 64, 000 litres of material which is 12% of the total of leakages in the city. The most significant of the canal leaks dates to 2016 and at 30,000L accounts for around half of this total.

These ‘sensitive’ incidents were the subject of evidence given before the Oireactas committee by ESB Networks representatives on 10 July 2019, in the course of which they maintained that the leaked fluid was ‘bio-degradable’ and implied that on this basis the material didn’t represent a threat to the environment.  However this position was challenged by Committee member Brian Stanley TD:

“It was said that what leaked from the underground cables is biodegradable. However, a confidential ESB document shows the ESB had been fully aware of the environmental hazards caused by those leaks since 2009, which is concerning. The document also states the Inchicore circuit presents the highest environmental risk due to the fact that its route runs parallel to the Grand Canal. That shows there already was some concern at that point that the environmental impact was severe. It went on to state that a fluid replacement and maintenance report on the Grand Canal in Dublin was conducted in 2014, and that ESB Networks had considerable difficulties accessing that route’s cables in order to repair leaks. The report claimed this was an area where leaks “could present a very high environmental impact”. Between 2012 and 2014, 10,000 l of oil leaked into the waterway alone. It is hugely concerning that this was not brought into the full light of day at the time”.

ESB representative Paul Mulvaney responded as follows:

“First, Deputy Stanley mentioned a specific leak and said that a certain amount of fluid went into the canal. However, that fluid did not leak into the canal. There was a leak from a cable near the canal, but the canal banks are impermeable clay structures for keeping water in, and so the only way for fluid to get into the canal is to go in over the top. As that particular cable is 1.2 m below the level of the canal, no fluid from that particular leak got into the canal”.

This evidence is however contradicted by one of the findings in the February 2020 EPA report where it states:

‘in 2014 ESB networks acknowledged that a leak resulted in fluid entering the Grand Canal. There is also reference to unspecified ‘mitigation measures’ relating to this incident over a period of 6 months”.

Regarding the role of Waterways Ireland (WI), the agency responsible for managing the canal, EPA refers to their role in terms of ‘recording and responding to water pollution incidents in canals associated with oil slicks. There is also a vague reference to ‘mitigation measures’ relating to this incident over a period of months. The nature and extent of the mitigation measures is not specified in the report.

In a further reference it is stated that, on 6 June 2019, EPA ‘engaged’ with WI and it is made clear, in terms of the sequence of events, that it was only subsequent to this that WI notified EPA of pollution incidents, This creates a difficulty for WI in terms of their capacity to deal effectively with pollution of the waterway, as it is very clear from the EPA report that WI were aware of Grand Canal pollution incidents at least since 2014.

Significantly, at no time since this very significant controversy broke in the media in June 2019, have Waterways Ireland made any public comment or clarification on their role in responding to or otherwise managing a series of pollution incidents in the vicinity of an important urban waterway for which they have responsibility.

Finally we can refer to the  conclusions in the EPA report as regards prosecutions for contravention of environmental legislation or other lines of action.


“ESB have identified that the fluid lost from the cable leaks is often a mixture of mineral oil and linear alkyl benzene and therefore must be considered hazardous”

“While ESB Networks report that they consulted a 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 have established two protocols since June 2019 to deal with historic and future leaks and EPA 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”

“EPA acknowledges that decommissioning of fluid filled cables will be challenging but considers fluid filled cables that have a high occurrence of leakage and are in proximity to sensitive receptors should be prioritised for decommissioning”

In terms of any future prosecutions or legal actions – this is the subject of an EPA recommendation to relevant Local Authorities along the lines that they should review their powers under Water Pollution legislation and establish if ‘a prosecution ……would be successful, appropriate or necessary’.

Following are links to sources mentioned:

Oireachtas Committee Debate:…/highlight%5B0%5D=esb&highlight%…

EPA Report:…/ne…/pressreleases2020/name,67808,en.html

Contact for further information: Reg McCabe, IWAI Dublin PRO



APRIL 2020

Our Facebook Page