Bathing Water Quality Dublin City Council Environment Strategic - - PowerPoint PPT Presentation

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Bathing Water Quality Dublin City Council Environment Strategic - - PowerPoint PPT Presentation

Nov 25, 2023 13 likes •308 views

Dublin Bay Bathing Water Quality Dublin City Council Environment Strategic Policy Committee November 2018 Irish Water Bathing Water Quality Sources of Pressure Urban Wastewater Wastewater Treatment Plants Storm Water

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Dublin Bay Bathing Water Quality

Dublin City Council – Environment Strategic Policy Committee November 2018 Irish Water

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2

Bathing Water Quality

Sources of Pressure

  • Urban Wastewater

– Wastewater Treatment Plants – Storm Water Overflows

  • Storm water (Urban) Run-Off
  • Agricultural Sources
  • Misconnections
  • Pollution from Other Sources (Seabirds & Animals)

Aim of Bathing Water Quality Regulations

  • Reduce risk to bathers from bacterial pollution
  • Establish pro-active approach to assessment of pollution risks and

management of bathing waters

  • Promote increased public involvement & communication of information
  • n bathing water quality
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SLIDE 3

1

Ringsend WWTP Upgrade

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SLIDE 4

Overview of Ringsend WwTP site

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WWTP Plant Overloaded:

  • Non-compliant with Urban Wastewater Treatment Directive – ECJ Case
  • Non-compliant with EPA Wastewater Discharge Licence
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Project Scope

Project Strategy – Biological Nutrient Removal

  • Achieve UWWTD & Licence compliant effluent for “sensitive waters”

through improved treatment retaining existing sea outfall.

  • Provide compliance and capacity to service growth in 2 Phases:

1. Capacity Upgrade with nutrient removal technology. Additional Capacity 400,000 Population Equivalent (PE). 2. Retrofit existing Sequencing Batch Reactors (SBRs) with nutrient removal technology to bring total capacity up to 2,400,000 PE.

Planning Approvals

  • Phase 1 doesn’t require Planning Approval. Capacity Upgrade

provided under existing Planning Approval.

  • Phase 2 requires Planning Approval.
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Nutrient Removal Technology (AGS)

Process Proving Step 1

  • PPS1 completed in

2016. Process Proving Step 2

  • PPS2 construction

complete June 2017

  • Testing period start-up

July 2017

  • Various loadings

scenarios tested

  • PPS2 Signed Off
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Ringsend - Current Project Status

  • Ringsend SID Planning Application
  • Submitted in June 2018
  • Allowance of 1 year for application – anticipated grant of approval in Q3

2019

  • Capacity Upgrade Contract (under current planning approval)
  • Contract commenced Q4 2017
  • Required to achieve compliance with UWWTD and capacity requirements

ECJ infringement case/ Dublin region growth

  • Retrofit Stage 1 Contract (new approval required)
  • In Tender process at present
  • Commence construction Q3/Q4 2019 subject to Planning Approval
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Water Quality Modelling

  • Water Quality Impact Assessment prepared for

Environmental Impact Assessment Report (EIAR)

  • Model Runs produce Plots for E Coli during

Bathing Season for: – Increased flow rates for future scenario – Modelling at licence limit for E Coli: 100,000 E Coli/100ml

  • Note : Average E Coli discharge measured in

2018 was 32,000 E Coli/100ml. 32% of license limit value

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Future Scenario (2.4M PE): Discharge during Bathing Season

Everything in Blue is at Good Quality below 500 E Coli/100ml 95%ile. Everything in White is at Excellent Quality below 250.

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Future Scenario (2.4M PE): Discharge during Bathing Season – Storm Event

Everything in Blue is at Good Quality below 500 E Coli/100ml 95%ile. Everything in White is at Excellent Quality below 250.

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2

Storm Water Overflows

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Storm Water Overflows

To River To WWTW

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SLIDE 13
  • 1. Drainage Area Plans (DAPs)
  • 2. Wastewater Network

Programmes & Projects

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Wastewater Networks

40% network not in GIS. 30% network based on poor/low confidence data. Majority Network Models out of date/ low confidence

Solutions:

Wastewater Networks – in GIS

Key Challenges:

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SLIDE 14

The DAP - investigation of the failure mechanisms causing service failures on the network using a verified hydraulic model

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Need for DAPs

Investment Needs & Notional Solutions Prioritised Costed Solutions within a Plan and Programme High Level DAP Assessment for Investment Planning Detailed DAP Assessment for Project Planning Sewer Flooding Pollution Incidents Growth Climate Change Urban Creep

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SLIDE 15

4 Stages in DAP Process

  • Stage 1 : Data Gathering
  • Stage 2 : Model Build
  • Stage 3: Risk Assessment
  • Stage 4: Assess Options &

Design Development

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DAP Process

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SLIDE 16

| Social Media Dublin 2018

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IR, CXI FC B, CXI B B IG IG

B Break CXI Defective Intruding Connection DES Deposits - Silt FC Fracture Circumferential IG Infiltration Gushing IR Infiltration Running SA Survey Abandoned

SA, DES

Manhole Surveys Pipe (Sewer) Surveys

DAP Stage 2 - Asset Surveys

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DAP Stage 2 Model Verification Flow Monitoring

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9C Sewer North Fringe & North Dublin Drainage Scheme City Centre Rathmines & Pembroke Dodder Valley Sewer

B

Bray & Shanganagh 9B Sewer

Lower Liffey Valley Catchment

West Pier

9B Sewer

Ringsend WWTP

Leixlip WWTP

Shanganagh WWTP

Dublin Bay – Wastewater Catchments

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Storm Water Overflows

Catchment

  • No. of

Storm Water Overflows (SWOs) DAP in Place (Consultant) DAP Status End Q4 2018 Dodder Valley 23 Y (WSP) Stage 2 Rathmines & Pembroke 24 Y (Atkins) Stage 2 North Fringe / North Dublin Drainage Scheme 87 Y (RPS) Stage 2 City Centre 88 Y (Atkins) Stage 4 West Pier 29 Y (WSP) Stage 2

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SWO Identification

SWO’s City Centre SWO’s North Fringe/NDDS

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Capacity Mapping – Wet Day

% Capacity Remaining

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Critical Asset Failure

Flooding & Pollution Main Lift Pumping Station

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Wastewater Networks Other Initiatives

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Wastewater Network Programmes & Projects

National Programmes

Storm Water Overflow (SWO) Survey, Assessment & Monitoring Programme (€6M) Sewer Rehabilitation Programme (€52M) Wastewater Pumping Station Telemetry Programme (€7M) Wastewater Pumping Station Capital Maintenance Programme (Dublin City Only)

Investment Plan Projects

Doldrum Bay North & South Docklands

Progression of Infrastructure Projects – Subject to DAP outputs

City Centre WW Network Rathmines & Pembroke WW Network Dodder Valley Reinforcement WW Network NDDS Reinforcement WW Network

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SLIDE 25

|

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INSPECTION PLANNING SPECIMEN DESIGN & COSTING CONDITION ASSESSMENT SELECTION PROCESS DETAILED DESIGN/DELIVERY CONDITION ASSESSMENT REGULATORY REPORTING

Sewer Rehabilitation Programme

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Sewer Rehabilitation Prioritisation

1 Galway C ity D0050 S M29245901 S M29245903 C C 300 300 VC VC 05/07/2005 5 145.45 240 320 4.06 25 100 125

508

2 Galway C ity D0050 S M29245902 S M29245907 C C 375 375 VC VC 05/07/2005 5 40 240 720 4.06 25 100 125

507

3 R amelton D0341 S C 22212106 S C 22212107 C C 225 225 PVC C O 16/05/2013 5 14.72 165 371 3.99 20 100 120

479

4 E nnis c

  • rthy

D0029 S S 97393503 S S 97393510 C C 225 225 C O VC 20/08/2013 5 12.28 200 684 3.60 25 100 125

450

5 E nnis c

  • rthy

D0029 S S 97396902 S S 97395901 C R 600 225 700 VC 02/10/2013 5 200 320 320 3.49 25 100 125

436

6 R amelton D0341 S C 22216105 S C 22216101 C C 225 225 C O C O 02/07/2013 5 3.8 240 240 3.49 10 100 15 125

436

7 R amelton D0341 S C 22214003 S C 22214101 C C 150 150 C O C O 13/05/2013 5 6.24 210 300 3.92 10 100 110

431

8 C arrigart D0523 S C 12369401 S C 12369502 C C 150 150 C O C O 20/02/2013 5 231.11 560 16640 3.89 10 100 110

427

9 K ilmac reannan D0513 S C 14201302 S C 14201401 C C 225 225 C O C O 09/04/2013 5 9.07 165 360 3.39 10 100 15 125

424

10 Downings D0350 S C 09389210 S C 09389203 C C 150 150 VC VC 19/09/2013 5 5.63 165 165 3.39 25 100 125

423

C apac ity - Infiltration [WOR K S ] DS height (mm) US pipe material S truc tural C

  • ndition

US width (mm) DS width (mm) US height (mm) S truc tural Mean S c

  • re

S truc tural Peak S c

  • re

S truc tural Total S c

  • re

Agglomeration DS s hape ID US node ID DS node ID US s hape ID Drainage C

  • de

DS pipe material C C TV S urvey Date TOTAL L IK L IHOOD S C OR E

  • WOR

K S TOTAL RIS K S C ORE

  • WORK

S TOTAL C ONS E QUE NC E S C OR E

Pipe Material [WOR K S ] S truc tural C

  • ndition

[WOR K S ] R ank

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Criticality & Risk – Thematic Mapping

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Key Actions

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Key Actions

  • Completion of DAPs with extension of Water Quality

Model for Dublin Bay to enable effective and risk based decisions to be made on future investment to achieve compliance and provide for growth

  • Maximise utilisation and resilience of existing Wastewater

Assets

  • Promote and collaboration on Stormwater Management

and application of Sustainable Drainage.

  • Continued Communication with Stakeholders & Public