Preliminary Site Assessment Site 39 Francis Street - Inchicore 110 kV Electricity Supply Board Project number: PR-427640_ACM_RP_ENV_055_0 07 April 2020 Preliminary Site Assessment Quality Information Prepared by Checked by Approved by Clare Crossan Environmental Geologist David Mullan Associate Director Kevin Forde Associate Director Distribution List # Hard Copies PDF Required Association / Company Name 0 1 Electricity Supply Board Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment Prepared for: Electricity Supply Board Prepared by: Clare Crossan Environmental Geologist T: +353-(0)87-702-3292 E: clare.crossan@aecom.com AECOM Ireland Limited 4th Floor Adelphi Plaza Georges Street Upper Dún Laoghaire Co. Dublin A96 T927 Ireland T: +353 1 238 3100 aecom.com Limitations AECOM Ireland Limited (“AECOM”) has prepared this Report for the sole use of Electricity Supply Board (“Client”) in accordance with the terms and conditions of appointment dated 03 July 2019. No other warranty, expressed or implied, is made as to the professional advice included in this Report or any other services provided by AECOM. This Report may not be relied upon by any other party without the prior and express written agreement of AECOM. Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM. Where any conclusions and recommendations contained in this Report are based upon information provided by others, it has been assumed that all relevant information has been provided by those parties and that such information is accurate. Any such information obtained by AECOM has not been independently verified by AECOM, unless otherwise stated in the Report. AECOM accepts no liability for any inaccurate conclusions, assumptions or actions taken resulting from any inaccurate information supplied to AECOM from others. The methodology adopted and the sources of information used by AECOM in providing its services are outlined in this Report. The work described in this Report was undertaken between 03 July 2019 and March 2020 and is based on the conditions encountered and the information available during the said period of time. The scope of this Report and the services are accordingly factually limited by these circumstances. AECOM disclaim any undertaking or obligation to advise any person of any change in any matter affecting the Report, which may come or be brought to AECOM’s attention after the date of the Report. The site reconnaissance consisted of a general external inspection of the site aimed at identifying potential sources of ground contamination affecting the site. An environmental compliance audit and/or detailed structural inspection of existing buildings were outside the project brief. Similarly, the site visit excluded detailed consideration of the ecological or archaeological aspects of the site, and if such are believed to be of potential significance then it is recommended that specialist advice is sought. Any risks identified in this Report are perceived risks, based on the information reviewed during the desk study and therefore partially based on conjecture from available information. The study is limited by the non-intrusive nature of the work and actual risks can only be assessed following a physical investigation of the site. It should be noted that the effects of ground and water borne contamination on the environment are constantly under review, and authoritative guidance values are potentially subject to change. The conclusions presented Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment herein are based on the guidance values available at the time this Report was prepared, however, no liability by AECOM can be accepted for the retrospective effects of any changes or amendments to these values. The opinions expressed in this report and the comments and recommendations given are based on a desk assessment of readily available information and an initial site reconnaissance by an AECOM employee. At this stage intrusive investigations have yet to be undertaken at site to establish actual ground and groundwater conditions and to provide data for an assessment of the geo-environmental status of the site. Unless otherwise stated in this Report, the assessments made assume that the sites and facilities will continue to be used for their current purpose without significant changes. Where assessments of works or costs identified in this Report are made, such assessments are based upon the information available at the time and where appropriate are subject to further investigations or information which may become available. Reference to historical Ordnance Survey (OS) maps and/or data provides invaluable information regarding the land use history of a site. However, it should be noted that historical evidence will be incomplete for the period predating the first edition and between the release of successive maps and/or data. Certain statements made in the Report that are not historical facts may constitute estimates, projections or other forward-looking statements and even though they are based on reasonable assumptions as of the date of the Report, such forward-looking statements by their nature involve risks and uncertainties that could cause actual results to differ materially from the results predicted. AECOM specifically does not guarantee or warrant any estimate or projections contained in this Report. Copyright © This Report is the copyright of AECOM. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited. Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment Table of Contents 1. 2. 3. 4. 5. 6. Introduction.............................................................................................................................. 1 1.1 Project Background........................................................................................................ 1 1.2 Project Objective............................................................................................................ 1 Scope of Work ......................................................................................................................... 2 Environmental Setting.............................................................................................................. 2 3.1 Topography .................................................................................................................... 2 3.2 Geology ......................................................................................................................... 2 3.3 Hydrology ...................................................................................................................... 3 3.3.1 Surface Water Features ................................................................................................. 3 3.3.2 Surface Water Quality .................................................................................................... 3 3.3.3 Flooding......................................................................................................................... 3 3.4 Hydrogeology ................................................................................................................ 4 3.4.1 Aquifer Classification ..................................................................................................... 4 3.4.2 Groundwater Vulnerability .............................................................................................. 4 3.4.3 Groundwater Quality ...................................................................................................... 4 3.5 Natural Habitats and Protected Species ......................................................................... 4 3.6 Regulatory Database Search ......................................................................................... 4 3.6.1 National Waste Collection Permit Office ......................................................................... 4 3.6.2 Storm Water Discharges ................................................................................................ 5 3.6.3 EPA Licensing ................................................................................................................ 5 3.7 Environmental Sensitivity ............................................................................................... 6 Source Audit Findings .............................................................................................................. 6 4.1 Site Description.............................................................................................................. 6 4.2 Surrounding Land Use ................................................................................................... 6 4.3 Historic Site Review ....................................................................................................... 7 4.4 Potential Sources........................................................................................................... 8 4.4.1 Cable Fluid Source ........................................................................................................ 8 4.4.1.1 Linear Alkyl Benzenes .............................................................................................. 8 Physical and Chemical Properties ............................................................................................ 8 4.4.1.2 Masse 106 Mineral Oil .............................................................................................. 9 4.4.1.3 Conclusion .............................................................................................................. 11 4.5 Source Audit Summary ................................................................................................. 11 Conceptual Site Model ........................................................................................................... 12 5.1 Qualitative Risk Assessment Methodology ................................................................... 12 5.2 Preliminary CSM Assumptions ..................................................................................... 14 Conclusions ........................................................................................................................... 18 Figures Appendix A Site Photographs Appendix B PSA Template Report Table of Contents Cross Reference Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment ABBREVIATIONS AECOM AECOM Ireland Limited APEC Area of Potential Environmental Concern bgl Below Ground Level BH Borehole BTEX Benzene, Toluene, Ethylbenzene and Xylene CSM Conceptual Site Model ESB Electricity Supply Board EPA Environmental Protection Agency GSI Geological Survey Ireland IEL Industrial Emissions Licence IPC Integrated Pollution Control ITM Irish Transverse Mercator km Kilometre kV Kilovolt LAB Linear Alkyl Benzene m OD Metres above Ordnance Datum NHA Natural Heritage Areas NAPL Non-Aqueous Phase Liquid NPWS National Park and Wildlife Service NWCPO National Waste Collection Permit Office OECD Organisation for Economic Co-operation and Development OPW Office of Public Works OSI Ordnance Survey Ireland PAH Polycyclic Aromatic Hydrocarbons PCB Polychlorinated Biphenyls PCOC Potential Constituents of Concern pNHA Proposed Natural Heritage Area PSA Preliminary Site Assessment RFP Request for Proposal SAC Special Area of Conservation SDS Safety Data Sheet SIDS Screening Information Datasets SPA Special Protection Area TPH Total Petroleum Hydrocarbons WAC Waste Acceptance Criteria WFD Water Framework Directive Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment EXECUTIVE SUMMARY Introduction AECOM Ireland Limited (AECOM) completed a Preliminary Site Assessment (PSA) of a cable fluid leak location on the Grand Canal southern tow path at Blackhorse Bridge, Inchicore, Dublin 8 (the site). ESB Networks operates and maintains a network of High Voltage (HV) underground cables of over 1,600 kilometres (km) across Ireland, of which approximately 205 km (175 km operational) are insulated by a cable fluid. The majority of the fluid filled cables are located in urban settings across Dublin City and Cork City. The remainder are located outside these areas with limited numbers of fluid filled cables in other counties. The length of each cable route varies and cable routes frequently extend across county boundaries. The cable fluid acts as an electrical insulator and aids the conduction of heat away from the conductor allowing the cable to be run more efficiently. Fluid filled cables are largely located in urban/suburban areas and so are particularly vulnerable to third party interference or damage. Over time cables can develop leaks due to corrosion/fracture/defects in the cable sheath and in joints and terminations. When such leaks occur, there is potential for pollution to occur to surface water, groundwater, soils and ecology. A leak was identified by ESB at this location in October 2008 and repaired the same month. AECOM understand that the fluid type lost from the cable was a mixture of linear alkyl benzene (LAB) and mineral oil based products. Objective The assessment reported herein comprises the first step of Stage 1: Site Characterisation & Assessment – Preliminary Site Assessment (PSA) and was carried out in accordance with EPA Guidance on the Management of Contaminated Land and Groundwater at EPA Licensed Sites (July 2013), and specifically the Guideline Template for Preliminary Site Assessment Report. This guidance draws on the EPA Code of Practice (CoP), Code of Reference for Unregulated Waste Disposal Sites (2007) and UK Environment Agency, Model Procedures for the Management of Land Contamination, Contaminated Land Report (CLR) 11 (September 2004). In terms of the data requirement for PSA reports, both the EPA CoP and CLR 11 outline that the findings of this initial risk assessment stage are largely based on desk-study information and a site walkover to identify potential pollutant linkages, which are then evaluated using appropriate criteria. As such, the objective of the PSA reported herein is to: · Identify potential contamination sources (i.e. the cable fluid), pathways (i.e. breathing in vapours, movement through made ground / soil) and receptors (i.e. who/what will be affected) and the likely interactions between each element; · Assess the potential severity of the hazard and the sensitivity of the receptor (ranging from minor to severe); · Assess the likelihood that a risk will occur (ranging from unlikely to high likelihood); and · Develop a preliminary conceptual site model (CSM) based on an overall assessment of each of these elements above. The preliminary CSM will then be used to identify potential risks to human health (site users and/or nearby residents) and controlled waters (i.e. groundwater and surface water) which may be associated with a fluid leak from the identified location. It should be noted that this stage of the risk assessment process is based mostly on qualitative information sources and identification of a potential risk at this stage does not necessarily indicate the presence of a risk, but rather the need for further assessment. A table cross referencing the template headings from the EPA Guidance Template and where the corresponding information is reported herein is presented in Appendix B. Assessment Findings Based on the findings of the desktop study, the overall environmental sensitivity of the site is considered to be moderate. Identified sensitive receptors within 1 km of the site include: · The Grand Canal located immediately north of the site, although this may be protected by low permeability clay (natural and/or engineered when the canal was constructed); Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment · The River Camac culverted 50 m west of the site, although this may be protected by low permeability clay deposits which are likely to be encountered beneath the site; and · The groundwater aquifer beneath the site, although this may also be protected by low permeability clay deposits which are likely to be encountered beneath the site. It is estimated that 3,765 litres of cable fluid was released in October 2008. It is assumed, based on information provided to AECOM by ESB, that the fluid lost was a mixture of LAB and mineral oil based products. Due to its high biodegradability, lower volatility and low solubility, it is considered that LABs are of less concern for adverse environmental impact than mineral oil based products. Given that there is potential for a mixture of both types of cable fluids to have been used at this site, potential contaminants of concern have been identified. A summary of the source audit findings is as follows: Area of Potential Environmental Concern Number APEC 1 Potential Contaminants Potential Media of Concern Impacted Leak at (39) Francis Street - Inchicore 110 kV LABs (October 2008) TPH BTEX VOCs SVOCs PCBs Soil Groundwater Soil Vapour Ground Gas The preliminary CSM developed for the site looked at potential source-pathway-receptor linkages identified during the assessment works and identified a moderate potential risk to the following receptors: · Site users due to the potential for ground gas generation resulting from degradation of NAPL (if present); and · Shallow groundwater due to potential impact to groundwater chemistry from the presence of NAPL and associated biodegradation products. A low to moderate risk was identified to site users from the potential for vapour migration from mineral oil based cable fluid. A low to moderate risk was also identified to site users from the migration of NAPL and potential breakdown products along preferential flow pathways such as existing underground services. Potential impact to the deeper groundwater aquifer was considered to be low to moderate due to the geology beneath the site. Risks associated with other potential source-pathway-receptor linkages were considered to be low. The risk assessment completed herein is preliminary in nature as it can only be based on an evaluation of qualitative data sources (i.e. not on intrusive site investigation works). Consequently, identification of potential risk does not necessarily indicate a risk to a receptor, rather that further assessment may be required to investigate assumptions made in the CSM and quantify whether a potential risk actually exists. Generally, where a low or very low risk has been identified further assessment may not be deemed necessary to assess a particular SPR linkage, although further assessment may be deemed to be required to investigate CSM assumptions where the potential risk is considered to be low or very low due to the sensitivity of the receptor. Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment Prepared for: Electricity Supply Board AECOM Preliminary Site Assessment EPA Contaminated Land and Groundwater Risk Assessment Methodology Table1. EPA Methodology Stage Methodology Report Reference Report Date Status 07 April 2020 Final Stage 1: Site Characterisation and Assessment 1.1 Preliminary Site Assessment 1.2 Detailed Site Assessment 1.3 Quantitative Risk Assessment PR-427640_ACM_RP_ENV_055 Stage 2: Corrective Action and Feasibility Design 2.1 Outline Corrective Action Strategy 2.2 Feasibility Study and Outline Design 2.3 Detailed Design 2.4 Final Strategy and Implementation Plan Stage 3: Corrective Action Implementation and Aftercare 3.1 Enabling Works 3.2 Corrective Action Implementation and Verification 3.3 Aftercare Source: EPA Guidance on the Management of Contaminated Land at EPA Sites Prepared for: Electricity Supply Board Pr-427640_Acm_Rp_Env_055_0 (Site 39 Psa Report).Docx AECOM Preliminary Site Assessment 1. Introduction AECOM Ireland Limited (AECOM) is pleased to present this preliminary site assessment (PSA) completed on behalf of Electricity Supply Board (ESB) for a site in Inchicore, Dublin 8, Ireland (the site). This report was commissioned by ESB under a request for proposal (RFP) issued on 26 June 2019 (Ref. Qd-354120-01R460_002-001-001) and carried out in accordance with AECOM proposal reference: PR-427640_ACM_PL_ENV_001_3, dated 03 July 2019. AECOM understand that ESB has undertaken these works on behalf of ESB Networks. 1.1 Project Background ESB Networks operates and maintains a network of High Voltage (HV) underground cables of over 1,600 kilometres (km) across Ireland, of which approximately 175 km are insulated by a cable fluid. The majority of the fluid filled cables are located in urban settings across Dublin City and Cork City. The remainder are located outside these areas with limited numbers of fluid filled cables in other counties. The length of each cable route varies and cable routes frequently extend across county boundaries. The cable fluid acts as an electrical insulator and aids the conduction of heat away from the conductor allowing the cable to be run more efficiently. Fluid filled cables are largely located in urban/suburban areas and so are particularly vulnerable to third party interference or damage. Over time cables can develop leaks due to corrosion/fracture/defects in the cable sheath and in joints and terminations. When such leaks occur, there is potential for pollution to occur to surface water, groundwater, soils and ecology. A leak was identified by ESB at the site in October 2009 and repaired the same month. AECOM understand that the fluid type lost from the cable was a mixture of linear alkyl benzene (LAB) and mineral oil based products. The site location is presented in Figure 1 and the site layout showing the site is presented in Figure 2. 1.2 Project Objective The assessment reported herein comprises the first step of Stage 1: Site Characterisation & Assessment – Preliminary Site Assessment (PSA) and was carried out in accordance with EPA Guidance on the Management of Contaminated Land and Groundwater at EPA Licensed Sites (July 2013), and specifically the Guideline Template for Preliminary Site Assessment Report. This guidance draws on the EPA Code of Practice (CoP), Code of Reference for Unregulated Waste Disposal Sites (2007) and UK Environment Agency, Model Procedures for the Management of Land Contamination, Contaminated Land Report (CLR) 11 (September 2004). In terms of the data requirement for PSA reports, both the EPA CoP and CLR 11 outline that the findings of this initial risk assessment stage are largely based on desk-study information and a site walkover to identify potential pollutant linkages, which are then evaluated using appropriate criteria. As such, the objective of the PSA reported herein is to: · Identify potential contamination sources (i.e. the cable fluid), pathways (i.e. breathing in vapours, movement through made ground / soil) and receptors (i.e. who/what will be affected) and the likely interactions between each element; · Assess the potential severity of the hazard and the sensitivity of the receptor (ranging from minor to severe); · Assess the likelihood that a risk will occur (ranging from unlikely to high likelihood); and · Develop a preliminary conceptual site model (CSM) based on an overall assessment of each of these elements above. The preliminary CSM will then be used to identify potential risks to human health (site users and/or nearby residents) and controlled waters (i.e. groundwater and surface water) which may be associated with a fluid leak from the identified location. It should be noted that this stage of the risk assessment process is based mostly on qualitative information sources and identification of a potential risk at this Prepared for: Electricity Supply Board AECOM 1 Preliminary Site Assessment stage does not necessarily indicate the presence of a risk, but rather the need for further assessment. A table cross referencing the template headings from the EPA Guidance Template and where the corresponding information is reported herein is presented in Appendix B. 2. Scope of Work To achieve the above objective, the following scope of work was undertaken: · A site walkover by AECOM staff (completed on 09 July 2019); · A desktop review of site history to identify areas of potential environmental concern (APEC); · A desktop review of publicly available information regarding the site’s environmental setting and sensitivity, including: ─ Geological Survey of Ireland (GSI) Groundwater Public Viewer Maps (https://dcenr.maps.arcgis.com/apps/MapSeries), accessed 04 - 11 July 2019; ─ EPA Geoportal Site (https://gis.epa.ie/EPAMaps), accessed 04 - 11 July 2019; ─ EPA Incidents Database (https://www.epa.ie/newsandevents/incidents/recent/), accessed 04 - 11 July 2019; ─ Ordnance Survey of Ireland (OSI) (http://geohive.ie), accessed 04 - 11 July 2019; ─ Glucksman Map Library, Trinity College Dublin, accessed 17 July 2019; ─ Office of Public Works (OPW) Flood Maps (http://www.floodinfo.ie), accessed 04 - 11 July 2019; ─ National Parks and Wildlife Service (NPWS) (http://webgis.npws.ie/npwsviewer/), accessed 04 - 11 July 2019; ─ National Waste Collection Permit Office (NWCPO) website (http://www.nwcpo.ie/), accessed 04 - 11 July 2019; · A review of information provided by ESB in the RFP; and · Data assessment and reporting. 3. Environmental Setting 3.1 Topography The site is located in Inchicore, Dublin 8, which has an elevation of approximately 34 m above ordnance datum (m OD) and is topographically relatively flat. The wider area is generally low-lying and typically flat. Grand Canal is located immediately north of the site, flowing to the east and discharging at the Grand Canal Dock. 3.2 Geology Teagasc Soils Map indicates the site locally is overlain by made ground. To the north and south of the site, the Quaternary geology is comprised of glacial till derived from the underlying limestone bedrock. The GSI Bedrock Geology Map (scale 1:100,000) indicates the site is underlain by the Dinantian marine basinal facies, a dark-grey fine-grained limestones and shales of the Lucan formation. No geological features are noted within the surrounding area. A number of geotechnical boreholes are located within the vicinity of the site. West of the site, four boreholes drilled as part of site investigation works for the Luas (tram rail system) adjacent to Blackhorse Bridge (R7491). The reported stratigraphy indicated fill/made ground up to 1.7 metres below ground level (m bgl), underlain by stiff clay up to 7.5 m bgl. Bedrock was encountered at a minimum depth of 6.5 m bgl. Prepared for: Electricity Supply Board AECOM 2 Preliminary Site Assessment Similarly, two boreholes and a trial pit were excavated as part of the Blackhorse Bridge renovation works (R2212). Fill/made ground was encountered at a maximum depth of 5.5 m bgl, underlain by boulder clay up to 7.6 m bgl. Bedrock was encountered at depths of 7 m bgl. South of Davitt Road, on the eastern portion of the site (R4123), associated with the River Camac culvert, one borehole has reported fill/made ground up to 12.4 m bgl. However, this could potentially be an error as made ground was encountered in other locations up to 3.6 m bgl, underlain by stiff gravelly clay. 3.3 Hydrology 3.3.1 Surface Water Features The site lies within the lower catchment of the River Liffey and Dublin Bay, which covers an area of 1,624 km2. The closest surface water body to the site is the Grand Canal (a proposed Natural Heritage Area (pNHA), Site Code 002104) located immediately north of the site. The canal flows to the east and discharges to the River Liffey Estuary approximately 6.5 km east of the site, which flows into South Dublin Bay (an SAC). This comprises the following protected sites: · South Dublin Bay Special Area of Conservation (SAC) (Site Code 000210); · South Dublin Bay and River Tolka Special Protection Area (SPA) (Site Code 004024); and · South Dublin Bay proposed Natural Heritage Area (pNHA) (Site Code 000210). As impervious materials are generally used to line canals during construction, it is not considered likely that the Grand Canal is in hydrological continuity with groundwater in the area. The Camac River flows from south to north and is the closest natural waterbody to the site; located approximately 50 m west of the site. The Camac River crosses (by culvert) the Grand Canal immediately east of the Blackhorse Bridge and discharges to the River Liffey. Given their proximity to the site, both the Grand Canal and the Camac River are considered to be sensitive surface water receptors. 3.3.2 Surface Water Quality The Grand Canal, which bounds the site to the south, is referred to as an Artificial Water Body (AWB) by the EPA under the Water Framework Directive (WFD). Waterways Ireland assess the biological quality of the Grand Canal, which along the section adjacent to the site during the period 2015 – 2017 was classified as ‘Good’ quality1. The most significant natural surface water feature in the wider area is the Camac River. The most recent reported EPA water quality status of the Camac River (monitoring station below Blackhorse Bridge) is a Q Value of 3 and a rating ‘Poor’. The WFD ecological status of the Camac River is characterised as being at risk of not meeting its WFD objectives. The most significant surface water feature in the wider area is the River Liffey Estuary. The WFD status of both the upper and lower sections of the estuary (classified as a Transitional Water Body) is classified as ‘Moderate’ and characterised as being at risk of not meeting its WFD objectives. 3.3.3 Flooding According to OPW Flood Maps, the site does not lie within the “River – Low Probability”, “River – Medium Probability” or “River – High Probability” modelled extent of land that might be flooded by rivers in a moderate to very extreme event. Parts of the surrounding area located within a 1 km radius to the west and east of the site lie within the “River – Low Probability”, “River – Medium Probability” and “River – High Probability”, indicating that flooding by rivers may occur during moderate to very extreme event in these areas. 1 EPA, Water Quality in 2017, An Indicators Report, 2018 Prepared for: Electricity Supply Board AECOM 3 Preliminary Site Assessment The site is not in close proximity to the extent of land affected by coastal flood events. 3.4 Hydrogeology 3.4.1 Aquifer Classification According to the GSI, the bedrock aquifer beneath the site is classified as a Locally Important Aquifer. The bedrock underlying the site is moderately productive in local zones. The soil permeability in the surrounding area is low; consequently the groundwater recharge in this aquifer is estimated by the GSI to be approximately 200 millimetres/year (mm/yr). Regional groundwater flow direction is likely to be to the north towards the River Liffey. A more detailed site assessment would be required to assess the local groundwater flow regime. According to the GSI wells and springs database, there are no springs but one groundwater well located within 1 km of the site. This well is located approximately 950 m to the south of the site and is recorded as industrial use with a ‘Good’ yield of 381 m3/day. The site is not mapped as being located within a Source Protection Area for either a public water supply or a group water supply scheme. 3.4.2 Groundwater Vulnerability The GSI National Groundwater Vulnerability Mapping identified that groundwater vulnerability associated with the site is “High”. However, some spatial variation in groundwater vulnerability is seen in the greater surrounding area of the site, where south if the site, groundwater vulnerability is recorded as “Extreme” in local areas and to the north of the site, “Moderate” vulnerability is reported. 3.4.3 Groundwater Quality Groundwater beneath the site is part of the Dublin Groundwater Body (IE_EA_G_008) which, according to the EPA website, is classified as having ‘Good’ status and is characterised as being not at risk. 3.5 Natural Habitats and Protected Species The Grand Canal is located immediately north of the site and is a pNHA. The River Liffey is located approximately 1.2 km north of the site. The River Liffey flows easterly into South Dublin Bay (an SAC, SPA and pNHA). Site Codes for each of these protected areas are provided in Section 3.3.1. There are no other protected areas within 1 km of the site. 3.6 Regulatory Database Search 3.6.1 National Waste Collection Permit Office The National Waste Collection Permit Office (NWCPO) website was reviewed to identify authorised waste facilities within the jurisdiction of Dublin City Council near the site. The NWCPO website indicated that there are two Waste Permitted Facilities within 1 km of the site as summarised in Table 2 overleaf. Prepared for: Electricity Supply Board AECOM 4 Preliminary Site Assessment Table 2. Dublin City Council Permitted Waste Facilities within 1 km of the Site Authorisation Number Facility Name Location Waste Activity WFP-DC-090008-02 Martin Services (Industrial) Limited Unit 11 Bluebell Business Park Bluebell Dublin 12 Wastes whose collection and disposal is not subject to special requirements in order to prevent infection (for example dressings, plaster casts, linen, disposable clothing, diapers) WFP-DC-110025-02 Rehab Enterprises Limited The Rehab Building Kylemore Road Ballyfermot Dublin 10 Photographic film, mixed packaging and waste electronic equipment 3.6.2 Storm Water Discharges Seven Irish Water storm water overflow discharge locations have been identified within 1 km of the site, as summarised in Table 3 below. Table 3. Storm Water Discharges Emission ID Name Register No. TPEFF0700D0034SW024 Ringsend D0034-01 TPEFF0700D0034SW032 Ringsend D0034-01 TPEFF0700D0034SW039 Ringsend D0034-01 TPEFF0700D0034SW073 Ringsend D0034-01 TPEFF0700D0034SW102 Ringsend D0034-01 TPEFF0700D0034SW103 Ringsend D0034-01 TPEFF0700D0034SW215 Ringsend D0034-01 3.6.3 EPA Licensing The EPA database of Waste Licences was consulted which identified two waste facilities within a 1 km radius of the site. Table 4 provides further details. Table 4. EPA Waste Facilities within 1 km of the Site Licence Number Facility Name Location Licence Status W0112 National Recycling and Environmental Protection Ltd John F Kennedy Drive, JFK Industrial Estate, Naas Rd, Dublin 12, Dublin Licenced W0221 Labre Park Civic Amenity Site Ballyfermot, Dublin 10, Dublin Licenced The EPA database of Industrial Emissions (IE) and Integrated Pollution Control (IPC) licences was consulted which identified a number of IE and IPC licences within 1 km of the site. Table 5 provides further details. Table 5. EPA IE and IPC facilities within 1 km of the site IE Register Number Facility Name Location Distance to Site Activity P0392-01, IE, Licenced Jamestown Metal Resources Limited Jamestown Road, Inchicore, Dublin 8., Dublin 850 m Industry P0796-01, IE, Surrendered Jamestown Shot Jamestown Road, Inchicore, Blasting & Metal Coating Dublin 8., Dublin Limited 930 m Industry Prepared for: Electricity Supply Board AECOM 5 Preliminary Site Assessment According to the EPA website, there are no Section 4 discharges2 to water within 1 km of the site and there have been no reported environmental incidents within 1 km of the site since at least 2010. 3.7 Environmental Sensitivity The overall environmental sensitivity of the site is considered to be moderate. Identified sensitive receptors within 1 km of the site include: · The Grand Canal located immediately north of the site, although this may be protected by low permeability clay (natural and/or engineered when the canal was constructed); · The River Camac culverted 50 m west of the site, although this may be protected by low permeability clay deposits which are likely to be encountered beneath the site; and · The groundwater aquifer beneath the site, although this may also be protected by low permeability clay deposits which are likely to be encountered beneath the site. 4. Source Audit Findings 4.1 Site Description The site is situated close to the intersection between Landsdowne Valley Park and Davitt Road, Inchicore, Dublin 8, Ireland. The leak site itself is paved and the wider area is composed by green areas (Lansdowne Valley Park on the south, a garden with dense vegetation on the north and a residential garden approximately 20 m southeast of the potential leak location). Furthermore, potential leak location is adjacent to the south bank of Grand Canal. It is estimated that the cable loss of fluid from the cable occurred in October 2008, with an estimated fluid volume loss of 3,765 Litres during that period. No evidence of impact from the cable fluid release was noted during the site walkover. There were no visual signs of an oily sheen or hydrocarbon odours in the Camac River or the canal. There was strong vegetation growth observed along the canal / river banks with no visual signs of dieback. 4.2 Surrounding Land Use Land use in the immediate vicinity of the site is predominantly light industrial with some residential. Land use in the vicinity of the site is summarised in Table 6. Table 6. Adjacent Land Use Site boundary Land Use North Grand Canal bounds the site immediately north and continuing north, Goldenbridge Walk is situated north of the canal and runs west to east. The land use is a commercial and residential end use. The R810 runs southwest to northeast and The Oblates Basketball Club is located to the north, adjacent to a large greenfield area, surrounded by additional residential dwellings. East The site is bound to the east by the LUAS ‘red line’ and Davitt Road (R812). Land use is predominantly residential dwellings and associated gardens with some sparse industrial and commercial units. An area of public open space (Lansdowne Valley Park) is located immediately east of the leak location, with the National Ambulance Service located in close proximity. Richmond Barracks is located 500 m northeast of the site. South The surrounding land use to the south (within a 1 km radius) is predominantly residential and commercial properties. The LUAS ‘red line’ is located adjacent to the Naas Road, with the River Camac flowing through Lansdowne Valley Park. West Approximately 240 m east of the site, adjacent to Jamestown Business Park, is the ESB Networks Transformer Compound with three substations (Inchicore 10kV Substation, Inchicore 220 kV Substation, 22 kV GIS Substation). Located 600 m northwest of the site is the Allied Industrial Estate and the Westlink Industrial Estate. 2 Section 4 discharges to water to support the characterisation of waterbodies for the 2nd Cycle of River Basin Management Planning. This dataset takes in account, among other datasets, the Section 4s dataset developed in 2005 as Point Source Pressures for the Article 5 Characterisation and Risk Assessment Report for the Water Framework Directive 2000/60/EC; (European Communities (Water Policy) Regulations 2003 (SI 722 of 2003)). Prepared for: Electricity Supply Board AECOM 6 Preliminary Site Assessment 4.3 Historic Site Review A review of historical maps and aerial photographs available from OSI, Glucksman Map Library (Trinity College Dublin) and Google Earth was carried out. A summary of the findings is presented in Table 7. Table 7. Historic Map and Aerial Photograph Review Year Description 1829 to 1841 (OSI) The site and the surrounding land appear to be undeveloped. The Grand Canal is present north of the site, with a road running southwest to northeast crossing at a Blackhorse Bridge, west of the site. There are aqueducts were the site is located and to the south is a quarry. To the east there is a cut out of the Grand Canal likely place to load the barges from the quarry. There is a paper mill to the northeast of the site. Richmond Barracks is present approximately 500 m northeast of the site the land is somewhat developed around it. 1875-1876 (Six inches to one statute mile) Trinity Map Land surrounding the site remains undeveloped, while the main developments from the previous map include Inchicore Railway Works (including saw mills) and the Great Southern and Western Railway line that runs southwest to northeast 600 m north of the site, as well as a retreat house. 1897 to 1913 (OSI) Significant developments can be seen on the 1897 – 1913 maps in the Ballyfermot and Jamestown areas. To the north and south of the site, minor residential development has occurred and one of the quarries to the south of the site is marked as disused, while the other is no longer shown. 1907-08 (Six inches to one statute mile) Trinity Map There is a hermitage along the south bank of the Grand Canal within the site. The road that crosses the Grand Canal is now labelled as Tyrconnell Road. The paper mill to the north has been replaced with a saw mill (the mill race still remains). There has been further development to the northeast of the site, including Goldenbridge school and church. A burial ground is reported to the north, while the area south of the site remains predominately undeveloped. 1936-37 (1:2,500) Trinity Maps A jam factory is located to the south of the site adjacent to the Camac River. There are no other significant changes compared to the previous historical maps. 1943-44 (Six inches to one statute mile) Trinity Maps The land to the south of the site has been heavily developed into a residential estate. To the north of the site beyond the saw mills is an Omnibus Works. A paint and varnish factory is located to the east along the Grand Canal. Keogh Square is to the northeast of the site and the Inchicore Railway works is now the Great Southern Railway Works. Beyond Blackhorse Bridge, a chlorination house is reported. 1970 (1:1,000) Trinity Maps The road running west to east along the southern bank of the Grand Canal is now labelled Davitt Road. A large factory is located to the south of the site with a smaller factory to the east. Kilworth road runs north to south from Davitt Road with one large factory grounds identified as an electrical substation. Opposite the factory on the northern side of the Grand Canal are several residential dwellings. There are no more significant changes compared to the previous map. 1990 (1:1,000) Trinity Maps The road on the northern side of the Grand Canal with the residential dwellings are is now named as Goldenbridge Walk. In the factory grounds to the south of the site there are three tanks, two smaller ones to the northwestern portion of the site with a large circular tank reported to the southwest. while in the southwestern corner is a large circle tank. 1995 (OSI) Substantial development of the Drimnagh, Inchicore and Jamestown areas is shown on the 1995 aerial photograph. Significant urbanisation is seen north and south of the site. The surrounding land has been developed for industrial, residential and commercial use. To the north of the site (within 500 m) significant industrial development at the Inchicore Rail Works station has occurred. Approximately 420 m north of the site two diesel storage tanks for the Inchicore Rail Works are noted. To the south of the site, within in a 1 km radius, significant urban residential and commercial development, with a significant decrease in agricultural land. 2000 (OSI) Minor industrial expansion is reported in the Jamestown area, 300 m northwest of the site. The remaining surrounding land to the north and south of the site remains largely unchanged and heavily urbanised. 2005 (OSI) More industrial development can be seen in the Jamestown and Inchicore areas with the development of connecting roads and industrial buildings. Within a 1 km radius, residential and commercial development remains unchanged. 2012 No significant changes have occurred from the previous map. Prepared for: Electricity Supply Board AECOM 7 Preliminary Site Assessment Year Description (Google Earth) 4.4 Potential Sources 4.4.1 Cable Fluid Source Information on the potential fluids released was provided in the ESB RFP document. Typically, fluid filled cables are installed in trenches approximately 1.2 m deep, 1.1 m wide and the depth to the top of the cable is typically 0.9 m – 1 m. The cables are typically surrounded by 0.35 m of sand and then the trench is backfilled with either Clause 804 fill or trench arisings. Based on information from the GSI, it is likely that the cable on this site is installed within sand and backfilled with made ground, therefore leaked fluid is likely to have migrated through either the sand surround or made ground (if of sufficient permeability). It is estimated that 3,765 litres of cable fluid was released in October 2008. It is assumed, based on records and Safety Data Sheets (SDS) provided to AECOM by ESB, that the fluid lost was a mixture of the following cable fluid products: · ‘T 3788’ manufactured by H&R ESP Ltd of Milton Keynes in the UK; · ‘Masse 106’ produced by Felten & Guilleaume Energietechnik AG in Germany; and · Shell Diala Cable Oil. T 3788 is a low viscosity blend of linear alkyl benzenes (LABs) (CAS # 67774-74-7). Shell Diala Cable Oil has the same CAS # as T 3788, so is essentially the same product but made by a different manufacturer. The SDS for Masse 106 does not give its CAS # or details of its composition but states that it is a blend of highly refined mineral oils and additives. 4.4.1.1 Linear Alkyl Benzenes Physical and Chemical Properties LABs have side alkyl chains of 10-13 carbon atoms in length attached to a benzene ring. The alkyl chain may be attached to the benzene ring at any position except the terminal (end) position. As LABs are a mixture, their precise physio-chemical properties are dependent upon the components of the mixture, but they are generally colourless, oily liquids, less dense than water, with very low aqueous solubility and low volatility. Their potential spreading in the ground will therefore be similar to other light non-aqueous phase liquids (LNAPL) but with very little mass loss due to volatilisation or dissolution. Information relating to the nature and toxicity of linear alkyl benzenes has been primarily sourced from the following documents: · Safety Data Sheet (SDS) for T 3788; · European Union Risk Assessment Report, Benzene, C10-13 alkyl derivatives, 20 June 1997; and · Organisation for Economic Co-operation and Development (OECD) Screening Information Datasets (SIDS) Initial Assessment Reports for High Production Volume Chemicals, United Nations Environment Programme, Chemicals Branch, May 2002. The table below summarises the basic physical and chemical properties of LABs. Table 8. Linear Alkyl Benzene Physical and Chemical Properties Property Description Molecular Weight 239-243 g/mol Melting Point <-70oC Boiling Point 251-320oC @ 1 atm (OECD) Prepared for: Electricity Supply Board AECOM 8 Preliminary Site Assessment Property Description o Vapour Pressure @ 25 C 6.5 x 10-5 kPa (OECD) Aqueous Solubility 0.041 mg/L (OECD) Henry’s Law Constant 9.34 x 10-4 atm-m3/mol (OECD) Density 0.86 @ 20oC Flash Point 140oC Explosive Properties None LAB (C12) has a calculated octanol-water partition coefficient (Koc) of 2.2x104 and is classified by the EU risk assessment as a high adsorptive substance. Degradation The OECD SIDS (2002) review concluded that LABs undergo “rapid primary biodegradation in natural waters and complete mineralisation by micro-organisms under aerobic conditions”. A measured half-life in water of four to nine days was reported. Microorganisms in sewage sludge and soil were reported to rapidly and completely biodegrade LABs. Anaerobic biodegradation was inferred to occur, but at a slow rate. Degradation in soil is expected to occur but to be slower than in surface water due to the much slower mixing and the limited availability of oxygen. Where oxygen is available, aerobic degradation would occur at the fringes of a body of LNAPL in the soil/groundwater, producing elevated carbon dioxide levels in the soil and potentially elevated alkalinity in the groundwater. In the absence of oxygen, anaerobic degradation may occur by methanogenesis or by reduction of sulphate, nitrate, ferric iron (Fe3+) and manganese (Mn3+). These processes could lead to reducing conditions in the groundwater, with depleted concentrations of sulphate (SO4-) and nitrate (NO3-) and increased concentrations of dissolved methane (CH4), ferrous iron (Fe2+) and dissolved manganese (Mn2+). Such conditions would be expected to occur close to the LNAPL body and locally downgradient. With increased distance from the LNAPL, mixing with the surrounding groundwater and aeration from seasonal fluctuations and groundwater recharge would gradually allow ambient (most likely oxidised) conditions to be reestablished. Toxicity According to the OECD review, LABs were assessed to be not acutely toxic to human health. Data from repeat exposure, reproductive and genotoxicity studies also indicated a low potential for toxic effects. The OECD concluded that “Linear alkyl benzenes do not present any significant acute or sub-chronic health effects by various exposure routes. LAB is not teratogenic (i.e. causing birth defects) and does not produce selective reproductive toxicity.” Laboratory studies have shown that repeated exposure to LABs may be irritating to the skin, and the SDS recommends the use of gloves when handling LABs. The low vapour pressure of LABs limits the potential for exposure via inhalation, and this is not expected to be a significant exposure route at normal temperatures. Eco-toxicity studies reviewed by the OECD found no acute toxic effects on aquatic species tested at concentrations up to and exceeding solubility limits. The only exception to this was for the water flea Daphnia magna. No data was available regarding terrestrial eco-toxicity studies. Due to its high biodegradability and rapid metabolism, the OECD concluded that LABs were of little concern for adverse environmental impact. The OECD and EU reviews of LABs both concluded that LABs were a low priority for further investigation. 4.4.1.2 Masse 106 Mineral Oil Information on Masse 106 has been obtained from a Safety Data Sheet (SDS) dated 1995 provided by ESB. Physical and Chemical Properties Prepared for: Electricity Supply Board AECOM 9 Preliminary Site Assessment Masse 106 is understood to be a blend of highly refined mineral oils and additives. The SDS does not provide information on the identity of the mineral oils or additives, or on their proportions within the oil. The SDS states that containers of Masse 106 should be kept tightly closed and in a well-ventilated space and that it should be used only in well-ventilated areas. This suggests that Masse 106 may contain volatile components. The table below summarises information from the SDS for Masse 106. Table 9. Masse 106 Physical and Chemical Properties Property Description o Vapour Pressure @ 20 C <0.01 hPa Aqueous Solubility negligible Density 888 kg/m3 Flash Point 145oC Flammability range 0.6% volume to 6.5% volume Kinematic viscosity@ 40oC 8.5 mm2/s Based on these properties, Masse 106 would behave as a relatively viscous LNAPL in the ground. The SDS states that if the product enters soil it will be adsorbed to soil particles and not be mobile. Degradation The SDS for Masse 106 indicates that it is not readily biodegradable. Nevertheless, as it is expected to be comprised mainly of petroleum hydrocarbon compounds, gradual degradation is expected to occur, especially in water. The rate of biodegradation is likely to depend on the availability of oxygen and of favourable geochemical conditions. As with LABs and with other petroleum hydrocarbons, where oxygen is available, aerobic degradation would be expected to occur at the fringes of a body of LNAPL in the soil/groundwater, producing elevated carbon dioxide levels in the soil and potentially elevated alkalinity in the groundwater. In the absence of oxygen, anaerobic degradation may occur by methanogenesis or by reduction of sulphate, nitrate, ferric iron (Fe3+) and manganese (Mn3+). These processes could lead to reducing conditions in the groundwater, with depleted concentrations of sulphate (SO4-) and nitrate (NO3-) and increased concentrations of dissolved methane (CH4), ferrous iron (Fe2+) and dissolved manganese (Mn2+). Such conditions would be expected to occur close to the LNAPL body and locally downgradient. With increased distance from the LNAPL, mixing with the surrounding groundwater and aeration from seasonal fluctuations and groundwater recharge would gradually allow ambient (most likely oxidised) conditions to be re-established. Toxicity The 1995 SDS for Masse 106 states that the components of the preparation are not expected to impart hazardous properties to the product. Whilst this suggests the product is not hazardous, it is noted that standards for hazard assessment and SDS production have evolved since 1995 and therefore the information cannot be relied upon with full confidence in relation to current standards for hazard assessment. The SDS indicates that Masse 106 is expected to be practically non-toxic to aquatic organisms. In relation to human toxicity, the SDS gives the following information: · It is expected to be slightly irritant, so all forms of skin contact should be minimised. It is not expected to be a skin sensitiser. · Respiratory protection is not normally required but it should be used only in well-ventilated spaces. It is based on mineral oils and other components not known to be carcinogenic. Prepared for: Electricity Supply Board AECOM 10 Preliminary Site Assessment 4.4.1.3 Conclusion Based on the above, underground leakage of LABs is not likely to lead to significant issues from dissolved hydrocarbons or vapours. Although the components of Masse 106 are not known and its aqueous solubility is stated on the SDS as “negligible”, it is unclear what this means in the context of dissolution of components from a NAPL. Based on the requirement for it to be used only in wellventilated spaces, it appears that Masse 106 contains some relatively volatile components. The main concern from LABs and a concern also for mineral oils such as Masse 106 is the potential for them to migrate and spread as a LNAPL, downwards through unsaturated soil that is present and then laterally in the vicinity of the groundwater table. The extent of LNAPL migration will depend on the properties of the surrounding soil and on the saturation and pressure distribution within the LNAPL. These in turn would depend on the quantity of cable fluid lost and the timescale over which the leakage occurred. Vapour impacts are considered to be unlikely from LABs but could be of concern for Masse 106. Degradation of the cable fluid may lead to the generation of ground gas (including carbon dioxide and methane) and affect groundwater chemistry in the vicinity and locally downgradient of the LNAPL. Given that a mixture of LABs and a mineral oil based cable fluid have been used in the past, potential contaminants of concern associated with mineral oil based fluids would include the following: · Total Petroleum Hydrocarbons (TPH); · Benzene, toluene, ethylbenzene and xylene (BTEX) compounds; · Volatile organic compounds (VOCs); · Semi volatile organic compounds (SVOCs); and · Polychlorinated biphenyls (PCBs). 4.5 Source Audit Summary Based on the assessment works completed, the primary APEC for this site comprises the leak location identified by ESB. This is presented in Figure 2 and a description is provided in Table 10. Table 10. Area of Potential Environmental Concern Number APEC 1 Potential Contaminants Potential Media of Concern Impacted Leak at (39) Francis Street - Inchicore 110 kV LABs (October 2008) TPH BTEX VOCs SVOCs PCBs Soil Groundwater Soil Vapour Ground Gas Other potential off-site sources have also been identified based on the type of activity. However, no information is available for these sites therefore the only APEC assessed herein is the leak site at the Grand Canal southern tow path at Blackhorse Bridge, Inchicore, Dublin 8. Prepared for: Electricity Supply Board AECOM 11 Preliminary Site Assessment 5. Conceptual Site Model A preliminary Conceptual Site Model (CSM) has been developed identifying potential contaminant sources, contaminant migration pathways and potential receptors. In the context of land contamination, there are three essential elements to any risk: 1. A source – a substance that is in, on or under the land and has the potential to cause harm or to cause pollution of controlled waters; 2. A receptor – in general terms, something that could be adversely affected by a contaminant, such as people, an ecological system, property, or a water body; and 3. A pathway – a route or means by which a receptor can be exposed to, or affected by, a contaminant. Each of these elements can exist independently, but they create a risk only where they are linked together, so that a particular contaminant affects a particular receptor through a particular pathway. This kind of linked combination of contaminant–pathway–receptor is described as a pollutant linkage. The preliminary CSM was developed to describe viable source-pathway-receptor (SPR) linkages for the site, which are presented in Table 15 below. By considering potential SPR linkages, an assessment of the human health and controlled water risks is made with reference to the significance and degree of the risk. The risk assessment has been undertaken with reference to BS10175-2011 + A2 2017 and CIRIA Document C552: ‘Contaminated Land Risk assessment - A Guide to Good Practice’ (2001). The preliminary risk assessment completed for this site is based on consideration of whether a potential source of contamination can reach a receptor, and hence whether it is of major or minor significance. Considering that assessment works are still at preliminary stage and no intrusive investigation work has been completed, development of the preliminary CSM and assessment of potential risk is based on information provided by ESB on the nature of the leak, and on the AECOM site reconnaissance and desk based study. As such, only a qualitative assessment can be made around potential risks to receptors. This means that identification of potential risk does not necessarily indicate a risk to a receptor, rather that further assessment may be required to investigate assumptions made in the CSM and quantify whether a potential risk actually exists. 5.1 Qualitative Risk Assessment Methodology A qualitative risk assessment has been carried out by assessing the severity of the potential consequence, taking into account both the potential severity of the hazard and the sensitivity of the target, based on the categories given in Table 11 below. Table 11. Potential Hazard Severity Definition Category Definition Severe Acute risks to human health, catastrophic damage to buildings/property, major pollution of controlled waters. Medium Chronic risk to human health, pollution of sensitive controlled waters, significant effects on sensitive ecosystems or species, significant damage to buildings or structures. Mild Pollution of non-sensitive waters, minor damage to buildings or structures. Minor Requirement for protective equipment during site works to mitigate health effects, damage to non-sensitive ecosystems or species. The likelihood of an event (probability) takes into account both the presence of the hazard and target and the integrity of the pathway and has been assessed based on the categories given in Table 12 overleaf. Prepared for: Electricity Supply Board AECOM 12 Preliminary Site Assessment Table 12. Probability of Risk Definition Category Definition High likelihood Pollutant linkage may be present, and risk is almost certain to occur in long term, or there is evidence of harm to the receptor. Likely Pollutant linkage may be present, and it is probable that the risk will occur over the long term. Low likelihood Pollutant linkage may be present, and there is a possibility of the risk occurring, although there is no certainty that it will do so. Unlikely Pollutant linkage may be present, but the circumstances under which harm would occur are improbable. The potential severity of the risk and the probability of the risk occurring have been combined in accordance with the following matrix in order to give a level of risk for each potential hazard as shown in the table below. Table 13. Level of Risk for Potential Hazard Definition Potential Severity Probability of Risk Severe Medium Mild Minor High Very high High Moderate Low/Moderate Likely High Moderate Low/Moderate Low Low Moderate Low/Moderate Low Very low Unlikely Low/Moderate Low Very low Very low A description of the levels of risk outlined in Table 13 is provided in the following table overleaf: Prepared for: Electricity Supply Board AECOM 13 Preliminary Site Assessment Table 14. Description of the Classified Risks and Likely Action Required Level of Risk Description Very High Risk There is a high probability that severe harm could arise to a designated receptor from an identified hazard, or there is evidence that severe harm to a designated receptor is currently happening. This risk, if realised, is likely to result in substantial liability. Urgent investigation and remediation are likely to be required. High Risk Harm is likely to arise to a designated receptor from an identified hazard. Realisation of the risk is likely to present a substantial liability. Urgent investigation is required and remedial works may be necessary in the short term and are likely over the long term. Moderate Risk Low Risk Very Low Risk 5.2 It is possible that harm could arise to a designated receptor from an identified hazard. However, it is either relatively unlikely that any such harm would be severe, or if any harm were to occur it is more likely that the harm would be relatively mild, if realised. It is possible that harm could arise to a designated receptor from an identified hazard, but it is likely that this harm, if realised, would at worst normally be mild. There is a low possibility that harm could arise to a receptor. In the event of such harm being realised it is not likely to be severe. Preliminary CSM Assumptions Based on the findings of the desktop study and information provide in the RFP by ESB, the following assumptions were made in development of the CSM: · The fluid assumed (based on records provided) to have leaked from the cable is a mixture of LAB and a mineral oil based cable fluid; · The geology beneath the site is assumed to comprise of engineered fill/made ground to a maximum depth of 5.0 m bgl, underlain by clay up to a depth of 7.5 m bgl. Limestone bedrock is reported as being variable across the area and present at a depth of approximately 6.5 - 8 m bgl; · Groundwater is assumed to be present at relatively shallow depths within the made ground; · It is assumed that the Grand Canal adjacent to the site is lined with an impermeable material such as clay, as was commonly used from the 1700s to early 20th Century to prevent leakage from the canal and thus loss of water level restricting navigation; · It is assumed that there is no direct connection between the site and the Grand Canal; · Other below ground utilities including mains water are assumed to be present in the vicinity of the site; and · It is assumed that industrial/commercial buildings adjacent to the site have no basements. The preliminary CSM is presented graphically in Figure 3. Prepared for: Electricity Supply Board AECOM 14 Preliminary Site Assessment Table 15. Conceptual Site Model Source Pathway LAB / Volatile TPH Inhalation of vapours which have and VOC migrated from the ground to above concentrations in ground buildings and basements. soils Soil and dust ingestion from near surface soils. NAPL and nonvolatile TPH, VOC, SVOC and PCB concentrations in soils NAPL and TPH, VOC, SVOC and PCB concentrations in soils Dermal contact with near surface soils. Receptor Site users in an industrial/commercial/low to high density residential scenario. Site users in an industrial/commercial/low to high density residential with plant uptake scenario. Severity Medium Medium Likelihood Low Likelihood Unlikely Potential Risk Discussion Low / Moderate Based on records provided, a mixture of LAB and mineral oil is assumed to be the cable fluid used. The low vapour pressure of LABs limits the potential for exposure via inhalation, and this is not expected to be a significant exposure route at normal temperatures. It is considered that there is a low to moderate risk from the inhalation of vapours from potential mineral oil-based products present beneath the site. Further assessment would be required to fully evaluate this potential risk. Low Based on the volume of cable fluid released and the assumed mixture of cable fluid used in the past, it is possible that a mineral based cable fluid may have migrated beneath low density residential houses with gardens or public open space adjacent to the canal. Given the likely depth to the cable, surface soils are unlikely to be affected and exposure via this pathways is not considered likely. Low Workers carrying out intrusive works adjacent to the site may come into contact with mineral oil based NAPL and impacted soil, meaning there will be a requirement to wear personal protective equipment to mitigate against potential impacts. Given the relatively low toxicity of LABs (assessed to be not acutely toxic), exposure to LABs is not considered to represent a significant risk. Moderate If a significant source of NAPL (LAB or mineral oil) is present on groundwater, there is potential for ground gas to be generated from degradation processes. The likelihood of ground gas being generated in significant quantities is considered to be low, however given the potential severity of the impact, further assessment would be required to fully evaluate this potential risk. Inhalation of fugitive dust from near surface soils. Ingestion of soils via consumption of vegetables grown in near surface soils. Intrusive site workers. Site users in an Migration of ground gas generated industrial/commercial/low to from the degradation of the cable fluid high density residential to above ground buildings. scenario. Minor Severe Likely Low Likelihood 15 Preliminary Site Assessment Source Pathway Receptor Severity Likelihood Potential Risk Discussion Public water mains likely to be present in the vicinity of the leak, servicing commercial and residential properties have the potential to be impacted. With respect to LABs, the WHO drinking water guideline (DWG) for the relevant aromatic fraction3 is 0.09 mg/l and as the solubility limit of LAB is 0.041 mg/L (OECD) i.e. less than the DWG, LAB cannot dissolve into the water supply above this level. Furthermore, water will be moving rapidly in the pipe under pressurised conditions making it unlikely to reach the solubility limit. NAPL and TPH, VOC, SVOC and PCB concentrations in soils Permeation of LAB NAPL through plastic water supply pipes. NAPL and TPH, VOC, SVOC and PCB concentrations in soils Migration of potential contaminants along preferential flow pathways such Nearby surface water bodies as underground services and including the Camac River permeable backfill around the and Grand Canal. electricity cable. NAPL and TPH, VOC, SVOC and PCB concentrations in soils Migration of potential contaminants along preferential flow pathways such as underground services and permeable backfill around the electricity cable. Site users in an industrial/commercial/low to high density residential with plant uptake scenario. Medium Unlikely Low In respect of the potential presence of mineral oil, the aqueous solubility of the known product used (Masse 106) is stated on the SDS as “negligible”. It is unclear what this means in the context of dissolution of components from a NAPL. ESB has consulted with Irish Water (statutory body responsible for water supply) regarding the potential risk for cable fluid present in the vicinity of water supply pipes. Following review of their records, AECOM understands that Irish Water do not have concerns regarding impact of water supplies from cable fluid leaks. It is therefore considered that the potential risk of a pollutant linkage being present is low. As a precaution, investigation works should be carried out as part of future assessment works to further assess this source-pathway-receptor linkage. Site users in an industrial/commercial/low to high density residential with plant uptake scenario. Medium Medium Unlikely Low Likelihood Low Low / Moderate It is understood that the leak at this location was repaired in October 2008. Given that there was no evidence of impact along the canal or the Camac River during the site walkover and no reported incidents of fluid release, it is likely that NAPL released from the cable has stabilised over the 12 year period since the leak was repaired and risk to the canal is low. Further assessment would be required to fully evaluate this potential risk. Likely to be a high concentration of services present in the vicinity of the leak given the urban setting. If the soil / made ground around the leak is generally clay, the leaking fluid will likely have migrated mainly along any permeable backfill around the cable. The cable fluids used are likely to absorb strongly to aquifer materials (made ground and clay), consequently the potential for migration over significant distances is considered to be low to moderate. Further assessment would be required to fully evaluate this potential risk. 16 Preliminary Site Assessment Source NAPL Pathway Migration in saturated and unsaturated soil. Dissolved phase leaching from NAPL or from soils containing elevated concentrations of TPH, VOCs, SVOCs and PCBs Receptor Groundwater beneath the site. Groundwater in superficial deposits beneath the site. Severity Medium Likelihood Likely Potential Risk Moderate Considering the volume of cable fluid released over the one-month leak period, it is considered likely that shallow groundwater has been impacted. Impacts could occur due to the presence of NAPL and associated biodegradation products. Further works would be required to assess for the presence of NAPL in the vicinity of the leak location and fully evaluate this potential risk. Medium Likely Moderate Considering the volume of cable fluid released over the one-month leak period, it is considered likely that shallow groundwater has been impacted. Further assessment would be required to quantify any impact from the presence dissolved phase contamination in groundwater. Medium Low Likelihood Low / Moderate Information on the local geology indicates the presence of underlying stiff clay, which would reduce vertical migration of groundwater to the bedrock aquifer. Further assessment would be required to fully evaluate this potential risk. Low / Moderate The volume of cable fluid released could cause major pollution of the canal, however given the canal is likely lined with impermeable material, the likelihood of horizontal migration through to the canal waters is considered low to moderate. In addition, no evidence of impact from the cable fluid release was noted during the site walkover, with strong vegetation growth observed along the canal banks. Further assessment would be required to fully evaluate this potential risk. Given the distance to the Camac River (50 m) , the potential risk of an SPR linkage being present is considered low to moderate. Further assessment would be required to fully evaluate this potential risk. Leaching from soil to groundwater. Vertical and horizontal migration of contaminants through groundwater. LAB, TPH, VOC, SVOC and PCB concentrations in groundwater Groundwater in limestone bedrock aquifer beneath the site. Horizontal migration of contaminants through groundwater to nearby surface water receptors. Nearby surface water bodies including the Camac River and Grand Canal. Discussion Medium Low Likelihood 17 Preliminary Site Assessment 6. Conclusions AECOM completed a Preliminary Site Assessment of the site located on the south bank of the Grand Canal to the east of Blackhorse Bridge, Dublin, 8. The objective of the works was to identify potential risks to human health and controlled waters that may be associated with a fluid leak from the identified location. Based on the findings of the desktop study, the overall environmental sensitivity of the site is considered to be moderate. Identified sensitive receptors within 1 km of the site include: · The Grand Canal located immediately north of the site, although this may be protected by low permeability clay (natural and/or engineered when the canal was constructed); · The River Camac located approximately 50 m to the west of the site, although this may be protected by low permeability clay deposits which are likely to be encountered beneath the site; and · The groundwater aquifer beneath the site, although this may also be protected by low permeability clay deposits which are likely to be encountered beneath the site. It is estimated that 3,765 litres of cable fluid was released over a one month period in October 2008. It is assumed, based on information provided to AECOM by ESB, that the fluid lost was a mixture of LAB and mineral oil based products. Due to its high biodegradability, lower volatility and low solubility, it is considered that LABs are of less concern for adverse environmental impact than mineral oil based products. Given that there is potential for a mixture of both types of cable fluids to have been used at this site, potential contaminants of concern have been identified. A summary of the source audit findings is as follows: Table 16. Area of Potential Environmental Concern Number APEC 1 Leak at (39) Francis Street – Inchicore 110 kV (October 2008) Potential Contaminants Potential Media of Concern Impacted LABs TPH BTEX VOCs SVOCs PCBs Soil Groundwater Soil Vapour Ground Gas The preliminary CSM developed for the site looked at potential source-pathway-receptor linkages identified during the assessment works and identified a moderate potential risk to the following receptors: · Site users due to the potential for ground gas generation resulting from degradation of NAPL (if present); and · Shallow groundwater due to potential impact to groundwater chemistry from the presence of NAPL and associated biodegradation products. A low to moderate risk was identified to site users from the potential for vapour migration from mineral oil based cable fluid. A low to moderate risk was also identified to site users from the migration of NAPL and potential breakdown products along preferential flow pathways such as existing underground services. Potential impact to the deeper groundwater aquifer was considered to be low to moderate due to the geology beneath the site. Risks associated with other potential source-pathway-receptor linkages were considered to be low. The risk assessment completed herein is preliminary in nature as it can only be based on an evaluation of qualitative data sources (i.e. not on intrusive site investigation works). Consequently, identification of potential risk does not necessarily indicate a risk to a receptor, rather that further assessment may be required to investigate assumptions made in the CSM and quantify whether a potential risk actually 18 Preliminary Site Assessment exists. Generally, where a low or very low risk has been identified further assessment may not be deemed necessary to assess a particular SPR linkage, although further assessment may be deemed to be required to investigate CSM assumptions where the potential risk is considered to be low or very low due to the sensitivity of the receptor. 19 Figures Figure 1. Site Location Plan Figure 2. Areas of Potential Environmental Concern Figure 3. Conceptual Site Model Prepared for: Electricity Supply Board AECOM Appendix A Site Photographs Prepared for: Electricity Supply Board AECOM PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. 1 Date: 01/11/2019 Direction Photo Taken: Southeast Description: Southeast facing view showing the potential leak location. Potential leak location is located in a pederstrian walkway adjacent to the canal. No evidence of visual contamination was observed in the adjacent canal water. Photo No. Date: 2 01/11/2019 Direction Photo Taken: West Description: LUAS stop situated about 65 m away from the potential leak location. Site Location: Site 39 – Davitt Road Project No. 427640 PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. Date: 3 01/11/2019 Direction Photo Taken: Description: Small substations close to the intersection between Landsdowne Valley Park street and Davitt Road. Site Location: Site 39 – Davitt Road Project No. 427640 PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. 4 Date: 01/11/2019 Direction Photo Taken: Description: Substations located on Davitt Road close to the potential leak location. Photo No. Date: 5 01/11/2019 Direction Photo Taken: Southwest Description: Construction works adjacent to the intersection between Kilworth Road and Davitt Road, approximately 70 m away from the potential leak location. Site Location: Site 39 – Davitt Road Project No. 427640 PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. 6 Date: 01/11/2019 Direction Photo Taken: East Description: Construction site located on Kilworth Road Photo No. Date: 7 01/11/2019 Direction Photo Taken: North Description: Presence of residential area including a park, car street and houses apprixiately 50 m southeast of potential leak location. Site Location: Site 39 – Davitt Road Project No. 427640 PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. Date: 8 01/11/2019 Direction Photo Taken: West Description: West facing view showing LUAS tracks and busy intersection between Naas Road and Davitt Road. Site Location: Site 39 – Davitt Road Project No. 427640 PHOTOGRAPH LOG Facility Name: ESB Cable Assessment Photo No. 9 Date: 01/11/2019 Direction Photo Taken: East Description: Intersection between Grand Canal and secondary stream, flowing to the northeast. Flow was observed to be high. Photo No. Date: 10 01/11/2019 Direction Photo Taken: North Description: Drains that channel Grand Canal Water into the secondary stream. Water was observed to be clean, no visually signals of contamination were observed during the site walkover. Site Location: Site 39 – Davitt Road Project No. 427640 Appendix B PSA Template Report Table of Contents Cross Reference Prepared for: Electricity Supply Board AECOM EPA Template Table of Contents Production Area Preliminary Site Assessment Report Executive Summary Executive Summary 1. Introduction Section 1 1.1 Project Contractual Basis & Personnel Involved Section 1 1.2 Background Information Section 1.1 1.3 Project Objectives Section 1.2 1.4 Scope of Works Section 2 2. Source Audit Findings Section 4 2.1 Current Site Operations Section 4.1 to Section 4.2 2.2 Previous Site Operations Section 4.3 2.3 Chemicals of Potential Concern Section 4.4 3. Site Environmental Setting Section 3 3.1 General Introduction Section 3 3.2 Regional Geology and Hydrogeology Section 3.2 and Section 3.4 3.3 Site Geology and Hydrogeology Section 3.2 and Section 3.4 3.4 Summary of Previous Site Sampling and Monitoring Data Not Applicable 4. Summary and Conclusions Section 6 4.1 Summary and Conclusions Section 6 4.2 Recommended Way Forward Separate Cover Letter 5. References Throughout Text Prepared for: Electricity Supply Board AECOM Prepared for: Electricity Supply Board AECOM