FLOOD RISK ASSESSMENT OF FARRAGH PROTEINS FOR SUBMISSION TO CAVAN COUNTY COUNCIL MONERY UPPER CROSSDONEY CO. CAVAN

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1 FLOOD RISK ASSESSMENT OF FARRAGH PROTEINS FOR SUBMISSION TO CAVAN COUNTY COUNCIL AT MONERY UPPER CROSSDONEY CO. CAVAN Prepared By: Traynor Environmental Ltd Belturbet Business Park, Creeny Belturbet Co. Cavan November 2011 EPA Export :04:03:24

2 TABLE OF CONTENTS 1.0 INTRODUCTION Background Scope of the Study Methodology Assessment of Minor Proposals in Areas of Flood Risk 6 Page 2.0 SITE DESRIPTION AND LOCATION Site Location The River Erne Existing Processes on Site Proposed Process Changes On Site Vulnerability Classification Existing Run-Off Generated by the Site Bund Integrity Assessments Effluent Drainage System Assessment FLOODING Types of Flooding Flood Zones Impacts of Flooding Flood Prevention on Site DEVELOPMENT PLANS AND POLICIES National, Regional and Local Spatial Plans and Studies Cavan County Development Plan(s) Consultations with Statutory Bodies 18 2 EPA Export :04:03:24

3 5.0 EXISTING HYDROLOGICAL ENVIRONMENT Data Collection Location of the Facility Existing Surface Water Drainage from Site Land Use Existing Site Geology and Hydrogeology Existing Flood Studies Greater Dublin Strategic Drainage Study Northwestern International River Basin Management Plan ( ) Existing Flood Records Possible Flooding Mechanisms FLOOD RISK ASSESSMENT Fluvial Flood Risk Tidal Flood Risk Pluvial Flood Risk Groundwater Flood Risk Flooding from Artificial Drainage Systems CONCLUSION 30 LIST OF TABLES No. Details Relating to Table Page No. 1 Drainage Area and Surface water Discharge Points for the Existing Site 9 2 Land Use Types for the Existing Site 20 3 Land Use Types for the Existing Site (Proposed Process Changes) 20 4 Possible Flooding Mechanisms 26 5 River Erne Extreme Flow Analysis 28 3 EPA Export :04:03:24

4 LIST OF FIGURES No. Details Relating to Table Page No. 1 Site Layout Map 11 2 Principal Causes and Types of Flooding 13 3 Location of the Site 19 4 Subsoil Map 22 5 Vulnerability Map 23 LIST OF PHOTOGRAPHS No. Details Relating to Photograph Page No. 1 Retaining Concrete Wall Built at Rear of site 14 2 View of Retaining Concrete Wall Built Overlooking River Erne 15 3 View of Retaining Concrete Wall (Facing North) 15 4 View of Retaining Concrete Wall located along the Northern boundary 16 5 View of Retaining Concrete Wall Compared to Level in River Erne 16 APPENDICES: Appendix Details Relating to Drawings Drawing No. A.1 Site Location Map A.2 OSI Ortho 2005 Aerial Map A.3 Historical 6 inch mapping series ( ) A.4 Historical Flood Risk Locations in the vicinity of Farragh Proteins A.5 Extent of Flood Risk Areas in the vicinity of Farragh Proteins A.6 Site Layout of Farragh Proteins Ltd showing Cross Section of River A.7 A.8 Cross Section through the River Erne, the surrounding land and the existing facility Cross Section Through the River Erne and the Existing factory showing Estimated Flood Levels B Microdrainage Suds Calculations - C Hydro Data For River Erne - D Bund Integrity Assessments - E Tank Integrity Assessments - F Effluent Drainage System Assessments - 4 EPA Export :04:03:24

5 1.0 INTRODUCTION 1.1 Background Traynor Environmental Ltd was commissioned by Farragh Proteins Ltd to undertake a Flood Risk Assessment (FRA). The FRA was carried out in accordance with The Planning System and Flood Risk Management, Guidelines for Planning Authorities, (hereafter referred to as the FRM Guidelines), published in November 2009 by the Department of Environment, Heritage and Local Government (DoEHLG) and the Office of Public Works (OPW). 1.2 Scope of the Study The main objective of the study was to carry out a flood risk assessment at the Farragh Proteins Ltd site, in accordance with the FRM Guidelines. The scope of the overall study is outlined below: Identification and assessment of all possible sources of flooding at the existing site including Fluvial (river) flood risk, Tidal flood risk, Groundwater flood risk, Pluvial flood risk, and flood risk from Artificial drainage systems; Assessment of flood alleviation measures already in place; Assessment of potential impact of flooding on the existing development. Assessment of the effectiveness of any mitigation measures; and Examination of the water levels that could occur adjacent to the existing facility. EPA Export :04:03:24

6 1.3 Methodology The methodology used for the flood risk assessment for the Farragh Proteins is based on The Planning System and Flood Risk Management Guidelines for Planning Authorities (2009). The FRM Guidelines require the planning system at national, regional and local levels to: Avoid development in areas at risk of flooding, particularly floodplains, unless there are proven wider sustainability grounds that justify appropriate development; Adopt a sequential approach if applicable to flood risk management when assessing the location for new development based on avoid, substitute, justify, mitigate and proceed; and Incorporate flood risk assessment into the process of making decisions on planning applications and planning appeals. 1.4 Assessment of minor proposals in areas of flood risk Applications for minor development, such as small extensions to houses, and most changes of use of existing buildings and or extensions and additions to existing commercial and industrial enterprises, are unlikely to raise significant flooding issues, unless they obstruct important flow paths, introduce a significant additional number of people into flood risk areas or entail the storage of hazardous substances. Since this application concerns primarily existing buildings and addition to existing activities which are unlikely to raise significant flooding issues, the sequential approach cannot be used to locate them in lower risk areas and the Justification test does not apply. 6 EPA Export :04:03:24

7 2.0 SITE DESCRIPTION, LOCATION & PROCESSES 2.1 Site Location Farragh Proteins is located in the townland of Monery Upper, Crossdoney, Co. Cavan. It is located approximately 2km north-west of Crossdoney village, on a local road that is just off the Ballananagh to Killeshandra Road. The factory is situated adjacent to the River Erne. The surrounding land is mostly agricultural and there are many drains running through the land towards the River Erne. 2.2 The River Erne The River Erne rises in Beaghy Lough, two miles south of Stradone in County Cavan and it flows for 64 miles through Lough Gowna, Lough Oughter and Upper and Lower Lough Erne to the sea at Ballyshannon, County Donegal. For 30 miles it is difficult to distinguish the river as it meanders its way through interconnected lakes nestling among the drumlin hills of Cavan and south Fermanagh. The river is 120 kilometres long and is very popular for fly fishing for trout and salmon, with a number of fisheries along both the river itself and its tributaries (Source: The site of the proposed development is adjacent to the River Erne, at a point where the river is approximately 10 metres wide. At this point it is extremely deep and slow flowing. The River Erne at this location is designated as a proposed Natural Heritage Area (Lough Oughter and Associated Loughs, pnha ) and a Special Protection Area (SPA ). Approximately 200 meters downstream of the proposed development site, the River Erne is also designated as a Special Area of Conservation (SAC ). The River Erne flows generally due Northeast passing by the Farragh Proteins site. 2.3 Existing Processes on site. The processing of animal by-products commenced at the site of Farragh Proteins in Crossdoney, Co. Cavan in It has been licensed by the EPA as a Category 3 (low risk) meat rendering plant since 2004 (Licence Reg. No. P ) and since then it has been collecting and processing raw material derived from this category. The facility operates 24 hours a day, 6 days a week. Buildings on site include a production area, loading area, raw material intake area, a boiler house, housing for the thermal oxidisation unit, laboratory 7 EPA Export :04:03:24

8 building, changing area, and work shop with stores area, a canteen and the main office block. The entire factory is within a bunded area. Since January 2005 there has been substantial investment on the site. The facility has been upgraded to become a modern production plant, which has incorporated the best technology available into each operation on the site. This saw the implementation of a more energy efficient production system and improvements in pollution abatement systems. 2.4 Proposed Process Changes On Site Farragh Proteins are seeking planning permission from Cavan County Council for- To increase in the raw material intake tonnage from 216 MT/day (EPA licence condition) to 125,000 MT per annum. Process modification to wet rendering on the CAT 3 line. DAFF Method 7. To install an evaporator on the CAT 3 line to reduce fuel consumption and CO 2 emissions. To installation of a new bio-filter (No. 4 and No. 5). To increase final treated effluent volume from 240m 3 /day to 340m 3 /day. To construct an additional aeration and balance tank to meet proposed Emission Limit Values for the final treated effluent. Replace 2 No. existing boilers with a single boiler. 8 EPA Export :04:03:24

9 2.5 Vulnerability Classification The topography of the site is generally sloping towards the River Erne. It is observed from Figure 5 that the aquifer at the Farragh Proteins Ltd site is of high vulnerability, as per the interim study based vulnerability map extracted from the GSI website Existing Run-Off Generated by the Site The area of the site has been calculated to be approximately 2.4 hectares in size. Using Microdrainage the run-off rate for the 1 in 100 year has been calculated to be 330 l/s for the hard surfaced areas. The site currently contains a surface water drainage system and discharges to the River Erne along the drainage ditch at the site boundaries of the site. Treated effluent discharge will be increased with the proposed process change from 240m 3 /day up to 340m 3 /day. The drainage layout is shown in Drawing No Table No. 1: Drainage Area and Surface water Discharge Points for the Existing Site SW 2 SW3 SW 4 SW 5 Small area of Front concrete Yard area concrete yard at Process building yard at behind Drainage area adjacent to the northern roof the offices & biofilter A2-2 section parking area The drainage area and surface water discharge points are shown in Figure 1 - Site Layout Map (Including New Balance Tank and Aeration Tank). 2.7 Bund Integrity Assessments Darcon Engineering, Walterstown, Castlebellingham, Co Louth carried out Bund Integrity assessments in accordance with Environmental Protection Agency (EPA) Guidelines The Storage and Transfer of Materials for Schedules Activities (2004) on the on the 18 th December The Six bund tanks passed at the Farragh Protein facility (Refer to Appendix D and E). 9 EPA Export :04:03:24

10 2.8 Effluent Drainage System Assessment The Drainage system was assessed by Darcon Engineering, Walterstown, Castlebellingham, Co Louth on the 18 th December The drainage system at the Farragh Protein facility in Crossdoney was in good order and were within the limits for water tightness of joints as specified in the NRA specifications, (Refer to Appendix F). 10 EPA Export :04:03:24

11 Figure 1 Site Layout Map (Including New Balance Tank and Aeration Tank) 11 EPA Export :04:03:24

12 3.0 FLOODING 3.1 Types of Flooding Flooding is a natural occurrence that can happen at any time in a wide variety of locations and plays a role in shaping the natural environment. River and coastal flooding are the most common forms which are noticeable, especially after prolonged and intense rainfall. Overland flow occurs when the amount of rainfall exceeds the infiltration capacity of the ground to absorb it. River flooding occurs when the capacity of a watercourse to convey water through an area is exceeded, blocked or restricted and this spills out into its floodplain. Flooding from artificial drainage systems can occur after intense rainfall and occurs when flow entering systems such as urban storm water drainage systems exceeds its discharge capacity and the system becomes blocked or cannot discharge due to high water level in the receiving watercourse. Estuarial flooding occurs when there are high flows in rivers entering the sea and a high tide prevents water flowing out to sea which may flood river banks. Coastal flooding occurs when sea water encroaches on land due to failure of coastal defences both natural (e.g. dunes) or man-made, or due to exceptional climatic or other factors. When this occurs, it can result in sewer flooding in urban areas, overland flow and flooding from groundwater in rural and urban areas. Groundwater flooding occurs when natural water levels stored in the ground rises above normal groundwater levels as a result of prolonged rainfall. The capacity of the underground reservoir is exceeded and the water seems to rise up from the ground. Incidences of infrastructure failure such as burst water mains, dam breaches or leaking canal and failure of flood defence or pumping station failure. Flooding of this nature can be sudden and may occur with or without warning. Development in certain areas also increases flood risk both upstream by restricting the capacity and conveyance function of the watercourse and floodplain system and downstream by decreasing the volume available for flood storage on the floodplain, altering flow routes on the floodplain or by changes to the channel which can increase the flow discharged to downstream location; and by increasing run-off due to changes in land management and introducing surfaces with reduced permeability such as roads, roofs and car parks. 12 EPA Export :04:03:24

13 Figure 2: Principal causes and types of flooding Source: DoEHLG & OPW (November 2009) the Planning System and Flood Risk Management. 3.2 Flood Zones Flood zones are geographical areas within which the likelihood of flooding is in a particular range and they are a key tool in flood risk management within the planning process as well as in flood warning and emergency planning. There are three types or levels of flood zones defined for the purposes of these Guidelines: Flood Zone A where the probability of flooding from rivers and the sea is highest (greater than 1% or 1 in 100 for river flooding or 0.5% or 1 in 200 for coastal flooding); Flood Zone B where the probability of flooding from rivers and the sea is moderate (between 0.1% or 1 in 1000 and 1% or 1 in 100 for river flooding and between 0.1% or 1 in 1000 year and 0.5% or 1 in 200 for coastal flooding); and Flood Zone C where the probability of flooding from rivers and the sea is low (less than 0.1% or 1 in 1000 for both river and coastal flooding). Flood Zone C covers all areas of the plan which are not in zones A or B. 13 EPA Export :04:03:24

14 3.3 Impacts of Flooding It is important to consider the consequences of climate change which is projected to impact on sea levels. There may be changes in the nature and pattern of rainfall events and weather patterns generally. Whilst the exact impacts of change are not known, it is widely agreed that climate change will result in higher risk of flooding both inland and coastal locations through the raising of sea levels and the occurrence of more intense rainfall events. 3.4 Flood Prevention on Site The rear wall of the facility is formed by a reinforced concrete retaining wall, which continues eastwards as far as the end of the effluent plant at which point it returns southwards. In addition it extends southwards along the west elevation of the Raw materials intake. Photograph 1 Retaining Concrete Wall Built at Rear of site River Erne Adjacent to the facility Top of Reinforced Concrete Wall 14 EPA Export :04:03:24

15 Photograph 2 View of Retaining Concrete Wall Built Overlooking River Erne Top of Reinforced Concrete Wall River Erne Adjacent to the facility Photograph 3 View of Retaining Concrete Wall (Facing North) Reinforced Concrete Wall 15 EPA Export :04:03:24

16 Photograph 4 View of Retaining Concrete Wall located along the Northern boundary. Reinforced Concrete Wall Photograph 5 View of Retaining Concrete Wall Compared to Level in River Erne Top of Reinforced Concrete Wall 16 EPA Export :04:03:24

17 4.0 DEVELOPMENT PLANS AND POLICIES 4.1 National, Regional and local spatial plans and studies A number of planning and policy documents were reviewed with respect to their flood protection policies. This flood risk assessment is set out to address these policies with regard to flood risk management. The Planning System and Flood Risk Management, Guidelines for Planning Authorities, published in November 2009 by the Department of Environment, Heritage and Local Government and the Office of Public Works; County Cavan Development Plan ; SEA Statement for the Cavan County Development Plan ; Other documents examined in the course of the flood risk assessment were as follows: Sustainable Development: A Strategy for Ireland, Department of the Environment, 1997; North Western International River Basin District (NWIRBD) 4.2 Cavan County Development Plan(s) The Cavan County Development Plan had established the following flood protection policies and objectives, which are relevant to the existing development: 1. Avoid development in areas at risk of flooding, particularly floodplains, unless there are proven wider sustainability grounds that justify appropriate development and where the risk can be reduced or managed to an acceptable level without increasing flood risk elsewhere; 2. At the project level, development either exceeding the specified thresholds for Environmental Impact Assessment (EIA) or development under the thresholds but with significant environmental effects and in an area at risk of flooding will require EIS. Flood risk will therefore need to be an integral part of the EIA process. Screening for EIA. 17 EPA Export :04:03:24

18 4.3 Consultations with Statutory Bodies Consultations were undertaken by Traynor Environmental Ltd with a number of statutory bodies during the Flood Risk Assessment process. These include: Cavan County Council Environmental Section (Ms Allison Treanor Senior Environmental Scientist); The Office of Public Works (OPW); 18 EPA Export :04:03:24

19 5.0 EXISTING HYDROLOGICAL ENVIRONMENT 5.1 Data collection Data required for the flood risk assessment was obtained from various sources, as described below. The topographical land level survey was carried out by Alan Traynor Consulting Engineers Ltd. The hydrometric data was available from the EPA. The historic flood data was obtained from the national flood hazard mapping website The sub-soil and groundwater vulnerability data was obtained from the geological survey of Ireland website Other information relating to the GDSDS, NWIBMP and other flooding projects etc were downloaded from the relevant websites. 5.2 Location of the facility The location of the site is shown in Figure 3. The plan/layout of the facility is presented in Appendix A. The blue line in Figure 5 represents the River Erne. Figure 3 - Location of the site Location of Site 19 EPA Export :04:03:24

20 5.3 Existing Surface Water Drainage from Site There are currently no petrol/oil interceptors on site, however Farragh Proteins are proposing to install oil interceptors on SW-2 (small area of concrete yard at the northern section), SW-4 (Yard area adjacent to biofilter A2-2) and SW-5 (Front Concrete yard behind the offices and parking area) discharge points. Farragh Proteins is planning to install cut off values on all storm water locations. 5.4 Land Use The total site area is approximately 2.43 hectare in size and consists predominantly of built areas and hard standing areas. The drainage layout is shown in Drawing No Lists of the area coverage of each land use type across the existing facility are shown in Table No. 1. As part of the proposed changes to the process, the land use % will change only slightly and any change can be deemed as negligible. Table No. 2: Land Use Types for the Existing Site Land Use Type Total Land use Area m 2 % Tank/Bund Area 2, Built Area 6, Hard Standing (Concrete) 12, Soft Standing (Gravel) 3, TOTAL 24, Table No. 3: Land Use Types for the Site (Proposed Process Changes) Land Use Type 20 Total Land use Area m 2 % Tank/Bund Area 2, Built Area 6, Hard Standing (Concrete) 11, Soft Standing (Gravel) 3, Proposed New WWTP Tanks Proposed Bio Filter Proposed Boiler TOTAL 24, EPA Export :04:03:24

21 5.5 Existing Site Geology and Hydrogeology The Geological Survey of Ireland (GSI) website provides information on their public online mapping service at on aquifer vulnerability and subsoil. These maps are presented in Figure 4 and 5 overleaf. The principal soil type in the area is surface water gleys/lihosols. The subsoil in the region of the site is variable (Figure 5), the site is shown as made ground, however West of the site is Alluvium soil caused by flooding. The Alluvium soil gives an indication of the floodplain. This information and map are compiled from the Geological Survey of Ireland (GSI) A review of the Ordnance Survey Ireland (OSI) revealed a good selection of historical aerial photographs for the site ranging from 1888 to the present day. OSI Site Location Map (Drawing No ); Ortho Colour aerial photography flown in July 2005 (Drawing No ); 21 EPA Export :04:03:24

22 Figure 4 Subsoil Map Made Ground (Farragh Protein) Alluvium Till Derived Chiefly From Granite Till Derived Chiefly From Namurian Rocks Bedrock Outcrop and Sudcrop Peat Till Derived Chiefly From Lower Palaeozoic Rocks Till Derived Chiefly From Limestone 22 EPA Export :04:03:24

23 Figure 5 Vulnerability Map Extreme (Rock near Surface) Extreme High Moderate Low 23 EPA Export :04:03:24

24 5.6 Existing flood studies Greater Dublin Strategic Drainage Study The Greater Dublin Strategic Drainage Study (GDSDS), completed in 2005, identifies policies for the management of drainage services in the Greater Dublin Area; however Counties such as Cavan would use this study for reference. The development at Farragh Proteins is long established since c.1951 and has not been designed in accordance with SUDS principles. The proposed upgrade of the rendering plant will not significantly alter the site layout. There will not be therefore be any significant increase in surface water runoff from the proposed plant upgrade North Western International River Basin District ( ) The North Western International River Basin District (NWIRBD) ( ), describes the plan for the entire NWIRBD. The Erne River is in the NWIRBD region. According to the NWIRBD, the principal pressure identified on these rivers is agricultural, forestry and wastewater discharges. Some surface water bodies have been substantially changed in character to allow uses such as flood defences and land drainage. 5.7 Existing Flood Records The record of historic flood events in the vicinity of the existing Farragh Proteins Ltd site was extracted from the National Flood Hazard Mapping Website It is observed from OPW Flood Map Report for the Area, that there are four prominent flooding locations within 4000 metres of the site (Please refer to Drawing No and ). OPW use Quality Codes to classify the flood event and report information according to the reliability and content of the information. The definitions of the codes are as follows: Code 1 - Contains, for a given flood event at a given location, reliably sourced definitive information on peak flood levels and/or maximum flood extents. 24 EPA Export :04:03:24

25 Code 2 - Contains, for a given flood event at a given location, reliably sourced definitive information on flood levels and/or flood extents. It does not however fully describe the extent of the event at the location. Code 3 - Contains, for a given location, information that, beyond reasonable doubt, a flood has occurred in the vicinity. Code 4 - Contains flood information that, insofar as it has been possible to establish, is probably true. Flood Area One location: Trinity Island Recurring. National Grid Reference H This area is located approximately >2,000m northwest (Downstream) of the site. Flood Quality Code: 3 Flood ID: 3418 Flood Area Two location: Erne Drummora Recurring. National Grid Reference H This area is located > 500m northwest (Downstream) of the site. Flood Quality Code: 3 Flood ID: 3420 Flood Area Three location: Erne Clonloskan Recurring. National Grid Reference H This area is located approximately >1,300m southwest from the site (upstream of the facility). Flood Quality Code: 3 Flood ID: 3385 Flood Area Four location: Erne Farranseer Recurring. National Grid Reference H This area is located approximately >1,900m southwest of the site (upstream of the facility). Flood Quality Code: 3 Flood ID: EPA Export :04:03:24

26 5.8 Possible Flooding Mechanisms Table No. 4: Summarises possible flooding mechanisms. Source/Pathway Significant Comment/Reason Tidal/Coastal Flood No Site is not at a coastal location Fluvial Flood Yes Erne River, drainage ditches Pluvial Flood No On site runoff is negligible. Groundwater Flood No Winter Groundwater level is estimated to be approximately 1.8m below existing ground level. Artificial Drainage Systems No Negligible with regular maintenance 26 EPA Export :04:03:24

27 6.0 FLOOD RISK ASSESSMENT Traynor Environmental Ltd reviewed the OPW National Flood Hazard Mapping website and found records of a number of past flooding incidences in the surrounding area of the site. There was no history of flooding on the site itself. The worst flooding recorded in the area for over 50 years occurred on 25 th November 2009 and prior to this date was 22 nd January The Flood risk from each of the five sources of flooding identified in Table No.3 (fluvial, tidal, pluvial, groundwater and from artificial drainage systems) are described in the following sub-sections. 6.1 Tidal Coastal Risk The site is no risk from tidal coastal flooding. 6.2 Fluvial Flood Risk The OPW flood mapping website was reviewed to determine if there was a previous record of flooding at the site. This review did not indicate any recorded flooding at Farragh Proteins. Drawing No.s and located in Appendix A.4 and A.5 respectively show the extent of the flooding in the vicinity of the site. This indicated a history of flooding along the River Erne in particular the meandering middle course of the river. The Erne River adjacent to the existing facility is defended by reinforced concrete retaining wall and as such relies partially upon the natural river bank crest to form the flood defence. The river banks are reasonably high and the levels from the site contour survey show the following: The lowest ground level of the existing facility is m OD (Bottom of the reinforced concrete wall) beside the River Erne and slopes upwards towards the road located on the Eastern boundary. The ground levels for the entire site have been previously raised. The location of the existing facility adjacent to the river could raise concerns of a potential for flooding. A level survey was also carried out to establish the relative levels of the yard and the flood plain on the opposite bank. As can be ascertained from this survey, the level of the yard slab increases from a low point of m (OD Poolbeg) at the base of the Retaining wall adjacent to the river. 27

28 This level is equivalent to the highest point on the flood plain, which is an isolated mound. The flood plain extends at this level for approximately 1km in a northerly direction and similarly in a westerly direction. A report was prepared by Mr. Micheal Mac Carthaigh, of the EPA on the Return Periods of Peak Water Levels in the River Erne in the vicinity of Farragh Proteins, Crossdoney, Co. Cavan. This report indicates the water levels that could occur, adjacent to the facility for the following return periods detailed in Table 3. Table No. 5: River Erne Extreme Flow Analysis. Flood Water Levels Year Return Period (Poolbeg datum) m OD m OD m OD For each of the return periods predicted, water levels are slightly higher than the low point of measured within the facility. At the time of the survey the river was relatively low. The level of the water was an average of 2.456m below the level of the yard slab. Cross Section A-A (Drawing No ) shows 2.456m between the base of the reinforced concrete wall and the water level measured on the 20 th July 2011.Cross Section B-B (Drawing No ) shows 2.83m between the base of the reinforced concrete wall and the water level measured on the 20 th July In addition the top level of the reinforced concrete retaining wall is a further 1.8m higher than the yard level. This would mean that in order to flow over the top of the retaining wall the river would have to rise by almost 3 meters, across the complete flood plain. Taking into account the above information, one can conclude that in the event of a rise in water level, the northern flood plain shall cater for any subsequent flooding, and that in the event of an extreme rise in the levels, the retaining wall will protect the site. 28

29 As the integrity of the retaining wall is of vital importance in the prevention of flooding at the site, Traynor Environmental Ltd recommends that the integrity and water tightness of the reinforced concrete wall and slab area, which forms a barrier between the site of the facility and the River Erne be inspected and tested as appropriate to demonstrate its suitability and adequacy to the satisfaction of Cavan County Council and the EPA. 6.3 Pluvial Flood Pluvial flooding is caused by surface water runoff due to direct rainfall. There are no historic records of pluvial flooding either within the site itself or within the environs of the Farragh Proteins site. As the land use % change is only slight, the pluvial flood risk is negligible. 6.4 Groundwater Flood Risk There are no records of historic groundwater flooding in the vicinity of the site. As there are no known historic flooding issue of any description on the site, ground water is not thought to present any significant flood risk. 6.5 Flooding from Artificial Drainage Systems The information collected from various sources does not indicate any significant risk of flooding from the artificial drainage systems, in the vicinity of the site. Therefore, the existing site is not at risk from artificial drainage system flooding. 29

30 7.0 CONCLUSION It is envisaged the proposed process changes on site will present no significant increase in risk of flooding either within the site or downstream of the site. The proposed upgrade of the rendering plant will not significantly alter the site layout. There will not be therefore any significant increase in surface water runoff from the proposed plant upgrade. To reduce any potential impact of the existing and proposed upgrade, the requirements of Cavan County Council and the EPA should be met. This may include as proposed the installation of oil interceptors and cut off valves on the storm water locations. For each of the flood return periods predicted, water levels are slightly higher than the low point of measured within the facility. However, the reinforced concrete retaining wall will acts as a barrier in such an event, is approximately 1.8 metres higher than the yard level. Taking into account the above information, one can conclude that in the event of a rise in water level, the northern flood plain shall cater for any subsequent flooding, and that in the event of an extreme rise in the levels, the retaining wall will protect the site, in the unlikely event that it rises above the site level. As the integrity of the retaining barrier wall is of vital importance in the prevention of flooding at this site, Traynor Environmental Ltd recommends the integrity and water tightness of the reinforced concrete wall and slab area, which forms a barrier between the site of the facility and the river Erne, be inspected and tested as appropriate to demonstrate its suitability and adequacy to the satisfaction of Cavan County Council and the EPA. Signed: Nevin Traynor BSc. Env, H.Dip I.T, Cert SHWW. For Traynor Environmental Ltd 30

31 APPENDIX A.1 SITE LOCATION PLAN FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 31

32 APPENDIX A.2 OSI ORTHO 2005 AERIAL MAP FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 32

33 APPENDIX A.3 HISTORICAL 6 INCH MAPPING SERIES FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 33

34 APPENDIX A.4 HISTORICAL FLOOD RISK LOCATIONS IN THE VICINITY OF FARRAGH PROTEINS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 34

35 APPENDIX A.5 EXTENT OF FLOOD RISK AREAS IN THE VICINITY OF FARRAGH PROTEINS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 35

36 APPENDIX A.6 SITE LAYOUT OF FARRAGH PROTEINS LTD SHOWING CROSS SECTION OF RIVER ERNE FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 36

37 APPENDIX A.7 CROSS SECTION THROUGH THE RIVER ERNE THE SURROUNDING LAND AND EXISTING FACILITY FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 37

38 APPENDIX A.8 CROSS SECTION THROUGH THE RIVER ERNE EXISTING FACTORY SHOWING ESTIMATED FLOOD LEVELS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 38

39 APPENDIX B MICRODRAINAGE SUDS CALCULATIONS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 39

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42 APPENDIX C HYDRO DATA FOR RIVER ERNE FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 42

43 GAUGING STATION DATA BELLAHILLAN STATION Gauging station data was accessed from the OPW website for the Bellahillan Station Table 1: Overview of Gauging Station Data GENERAL STATION DETAILS Station Name: Bellahillan Station No: Watercourse: Erne NGR: H Catchment Area (km 2 ): 318 Catchment: Erne Gauge Type: AR Datum: Poolbeg SUMMARY HYDROMETRIC STATISTICS Annual Average Rainfall (mm) 1 : 990 STATION HISTORY Period of Continuous Hardcopy Records: 1955 to 2005 Est'd Annual Losses (mm) 1 : 447 Period of Digitised Record: 1972 to 2002 Mean Annual Flow (m 3 /s): (Data derived for the period 1972 to 1998) Note 1 : Data extracted from the Environmental Protection Agency publication 'Hydrological Data', July 1997 DURATION PERCENTILES Flows equalled or exceeded for the given percentage of time (m 3 /s) (Data derived for the period 1972 to 1998) 1% 5% 10% 50% 80% 90% 95% 99% Levels equalled or exceeded for the given percentage of time (maod Poolbeg) (Data derived for the period 1972 to 2002) 1% 5% 10% 50% 80% 90% 95% 99% COMMENTS / NOTES Poor quality low and medium flow data - to be used for indicative purposes only. The annual maximum series provides flow and water level data for a period of 56 years at the Bellahillan Station (36011), which is located approximately 1.2km upstream from the site and duration percentiles and flow are also available for this station. 43

44 APPENDIX D BUND INTEGRITY ASSESSMENT REPORTS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 44

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48 APPENDIX E UNDERGROUND TANKS/HOPPERS FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 48

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50 APPENDIX F EFFLUENT DRAINAGE SYSTEM ASSESSMENT FARRAGH PROTEINS LTD FLOOD RISK ASSESSMENT 50

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57 Co en t ns of co For py in rig sp ht ect ow ion ne pu r r rp eq os ui es re o d nl fo y. ra ny he ru ot se.

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