Offaly County Council Edenderry Sewerage Improvement Scheme Preliminary Report Volume I
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OFFALY COUNTY COUNCIL EDENDERRY SEWERAGE IMPROVEMENT SCHEME PRELIMINARY REPORT VOLUME I For inspection purposes only. Consent of copyright owner required for any other use. Nicholas O’Dwyer Ltd., Offaly County Council, Consulting Engineers, County Buildings, Nutgrove Office Park, Charleville Road, Nutgrove Avenue, Tullamore, Dublin 14. Co. Offaly. Revision B – June 2005 PROJECT NO. 20290 Prepared by Approved by Issued by Initials Date Initials Date Initials Date Revision Reason for Revision GM 12/12/03 GM 12/12/03 JP 12/12/03 A Incorporate Client comments. GM 13/12/04 GM 13/12/04 JP 13/12/04 B Final Revisions GM 13/06/05 GM 13/06/05 JP 13/6/05 C D EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report CONTENTS VOLUME I 1. INTRODUCTION & SCOPE OF WORK 1 1.1 General 1 1.2 Scheme Objectives 1 1.3 Terms of Engagement 1 1.4 Scope of Work 3 1.5 Staging of Scheme 4 1.6 Environmental Impact Statement 4 1.7 Scheme Catchment Area 4 1.8 Importance of the Scheme 5 2. DATA COLLECTION AND EXISTING CONDITIONS 6 2.1 Wastewater Disposal and Population Served 6 2.2 Wastewater Generation and Pollution Load 6 2.3 Stormwater and Groundwater Infiltration 6 2.4 Wastewater Disposal Facilities 6 For inspection purposes only. 2.5 Receiving Waters Consent of copyright owner required for any other use. 7 3. EXISTING SYSTEM 8 3.1 General 8 3.2 Edenderry Wastewater Collection Network 8 3.2.1 Introduction 8 3.2.2 Foul / Combined and Surface Water Sewers 9 3.2.3 Existing Pumping Stations 11 3.2.4 Existing Overflows 15 3.3 Hydraulic Modelling of Existing System 17 3.3.1 General Methodology 17 3.3.2 Construction of Edenderry Hydraulic Model 20 3.3.3 Hydraulic Model Calibration 22 3.3.4 Hydraulic Analysis of Existing System 23 Nicholas O’Dwyer Ltd. i Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report 3.4 CCTV and SUS 2000 Survey 25 3.5 Existing Wastewater Treatment Plant 28 3.5.1 Introduction 28 3.5.2 Existing Wastewater Treatment Works Overview 28 3.5.3 Operation and Maintenance 31 3.5.4 Flow and Load Survey 32 4. POPULATION PROJECTIONS, WASTEWATER FLOWS AND STAGING OF THE SCHEME 38 4.1 General 38 4.2 Population Projections 38 4.3 Low Growth Trend 39 4.4 Medium Growth Trend 44 4.5 High Growth Trend 46 4.6 Phasing of the Works 48 5. EFFLUENT QUALITY 50 5.1 Receiving Waters 50 5.2 Effluent Quality 50 5.3 Urban Wastewater Treatment Regulations 51 5.4 River Boyne Water Quality Management Plan (WQMP) 52 5.5 Aspects of Boyne Catchment Hydrology 53 For inspection purposes only. Consent of copyright owner required for any other use. 5.6 River Boyne Water Quality 54 5.7 Required Effluent Standards 55 5.8 Recommended Effluent Standards for the River Boyne at Edenderry 58 5.9 Summary of Effluent Standards Adopted for Discharge to the River Boyne at Edenderry 60 5.10 Discharge Options to the River Boyne 60 6. WASTEWATER TREATMENT OPTIONS 61 6.1 General 61 6.2 Treatment Plant Capacity 62 6.3 Treatment Process Selection 63 6.3.1 Process Option 1 (Extended Aeration Plant) 64 6.3.2 Process Option 2 (SBR) 66 Nicholas O’Dwyer Ltd. ii Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report 6.3.3 Process Option 3 (Membrane Bioreactor) 67 6.3.5 Conclusions 68 6.3.6 Recommendations 69 6.4 Tertiary Filters 69 6.5 Treatment and Disposal of Solids Residues 70 6.5.1 Screenings & Grit 70 6.5.2 Sludge 70 6.6 Augmentation of Flow and Balancing of Effluent Flow 71 7. WASTEWATER COLLECTION NETWORK PROPOSALS 72 7.1 General 72 7.2 Hydraulic Model 72 7.3 Methodology 72 7.4 Upgrading of Pumping Stations 75 7.4.1 General 75 7.4.2 Connyborough Pumping Station 76 7.4.3 Clonmullen Lane Pumping Station 77 7.4.4 Carrick Road Pumping Station 77 7.4.5 Derrycorris Pumping Station 78 7.4.6 Corkery Lane Pumping Station 78 7.4.7 Killane Road Pumping Station 78 7.4.8 Blundell Wood Pumping Station 79 7.4.9 Rising Mains 79 For inspection purposes only. 7.5 Removal of OverflowsConsent of copyright owner required for any other use. 80 7.6 Sewer Upgrading 81 7.7 Extensions to Existing Collection System 85 7.8 Sewer Repair and Rehabilitation Works 86 7.9 Storm Handling Facilities at Wastewater Treatment Works 86 7.10 Summary of Proposed Measures 90 8. DESIGN PARAMETERS AND LAYOUT OF WASTEWATER TREATMENT PLANT 93 8.1 Summary of Design Parameters 93 8.2 Preliminary Layout of the Wastewater Treatment Works 93 8.3 Stormwater Tanks 94 9. SEPTICITY AND ODOUR CONTROL 95 Nicholas O’Dwyer Ltd. iii Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report 9.1 General 95 9.2 Physical Conditions for Septicity 95 9.3 Preventive Measures 97 9.4 Recommendations 98 10. STORMWATER NETWORK 99 10.1 General 99 10.2 “Assessment of Surface Water Drainage in Edenderry” 99 10.3 “Upper Boyne Flood Study” 100 10.4 Future Development 100 10.5 SUDS – Sustainable Urban Drainage Systems 102 10.5.1 General Description 102 10.5.2 Initial Data Required 103 10.5.3 Design Strategy for Drainage System 104 10.5.4 SUDS Conclusions 105 11. COST ESTIMATES 107 11.1 Preparation of Cost Estimates 107 11.2 Wastewater Treatment Works Expansion 107 11.2.1 Estimated Cost of Phase I 107 11.2.2 Estimated Cost of Phase II 107 11.2.3 Estimated Cost of Phase III 107 For inspection purposes only. 11.2.4 Summary ofConsent Estimated of copyright Waste owner requiredwater for anyTreatment other use. Works Costs 108 11.3 Annual Operation and Maintenance Costs 109 11.4 Improvements to Existing Wastewater Collection Network 109 11.4.1 Estimated Cost of Sewer and Manhole Rehabilitation 109 11.4.2 Estimated Cost of New and Upgraded Sewers 110 11.4.3 Estimated Cost of New Rising Mains 111 11.4.4 Estimated Cost of New / Upgraded Pumping Stations 111 11.4.5 Estimated Costs of Removing Combined Storm Overflows 113 11.4.6 Summary of Estimated Wastewater Collection Network Costs 113 11.4 Proposed Extensions to Wastewater Collection Network 114 11.5.1 Overall Summary Costs of Edenderry Sewerage Improvement Scheme 115 12. PROCUREMENT STRATEGY AND IMPLEMENTATION 121 12.1 Benefits of Traditional Procurement vs. DB/DBO Contracts 121 12.1.1 Design and Build 122 Nicholas O’Dwyer Ltd. iv Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report 12.1.2 Operating 122 12.1.3 Programme 123 12.2 Procurement Strategy 123 13. CONCLUSIONS AND RECOMMENDATIONS 124 13.1 Conclusions 124 13.2 Recommendations 125 VOLUME II APPENDICES Collection Network - Hydraulic Model Calibration Report For inspection purposes only. Consent of copyright owner required for any other use. Nicholas O’Dwyer Ltd. v Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report LIST OF DRAWINGS 20290/01 Edenderry Development Boundary 20290/02 Wastewater Collection Network - Existing 20290/03 Wastewater Treatment Works - Existing 20290/04 Wastewater Treatment Works Outfall Pipeline - Existing 20290/05 Flow and Rainfall Logger Locations 20290/06 CCTV / SUS Survey Results 20290/07 Existing Collection System Hydraulic Analysis - 1 Year Return Period 20290/08 Land Use Zoning Map (2003) 20290/09 Proposed Wastewater Treatment Works Extension - Option 1 Layout 20290/10 Proposed Wastewater Treatment Works Extension - Option 1 Sections 20290/11 Proposed Wastewater Treatment Works Extension - Option 2 Layout 20290/12 Proposed Wastewater Treatment Works Extension - Option 2 Sections 20290/13 Proposed Wastewater Treatment Works Extension - Option 3 Layout 20290/14 Proposed Wastewater Treatment Works Extension - Option 3 Sections 20290/15 Details of Existing & Proposed Pumping Station at Connyborough 20290/16 Details of Existing & Proposed Pumping Station at Killane Road 20290/17 Collection System H ydraulic For inspection Analysispurposes only. Following Proposed Upgrading of Consent of copyright owner required for any other use. Pumping Stations & Removal of Combined Sewer Overflows 20290/18 Proposed Sewer & Rising Main Upgrades 20290/19 Plan of Proposed Relief Sewer 20290/20 Proposed Foul Relief Sewer - Longitudinal Section 20290/21 Plan of Proposed Foul Sewers & Surface Water Scheme on Rhode Road & St. Mary’s Street. 20290/22 Proposed Foul Sewers - Longitudinal Sections - Rhode Road - ‘A’ Line 20290/23 Proposed Foul Sewers - Longitudinal Sections - St. Mary’s Street - ‘A’ Line 20290/24 Surface Water Scheme - Longitudinal Sections - ‘B’ Line and ‘C’ Line 20290/25 Proposed Combined Sewer on St. Mary’s Road - ‘D’ Line 20290/26 Proposed Foul Sewer & Rising Main at Connyborough - ‘E’ Line 20290/27 Land Use Zoning Map & Proposed Wastewater Collection System Nicholas O’Dwyer Ltd. vi Revision B - June 2005 EPA Export 26-07-2013:01:59:55 Edenderry Sewerage Improvement Scheme Preliminary Report 1. INTRODUCTION & SCOPE OF WORK 1.1 General Edenderry is a medium sized town situated in East Offaly close to the border with North-West Kildare. The town is situated closed to the upstream section of the River Boyne which forms the border between the two counties. In the 2003 Offaly County Development Plan, Edenderry is designated as a District Centre along with Tullamore, the county town and Birr.