Dublin Bay
Bathing Water Quality
Dublin City Council – Environment Strategic Policy Committee
November 2018
Irish Water
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
on bathing water quality
Overview of Ringsend WwTP site
4
WWTP Plant Overloaded:
• Non-compliant with Urban Wastewater Treatment Directive – ECJ Case
• Non-compliant with EPA Wastewater Discharge Licence
5
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.
6
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
7
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
8
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
9
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.
10
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.
1. Drainage Area Plans (DAPs)
2. Wastewater Network Programmes & Projects
13
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:
The DAP - investigation of the failure mechanisms causing service failures on the network using
a verified hydraulic model
14
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 GrowthClimate Change
Urban Creep
4 Stages in DAP Process
• Stage 1 : Data Gathering
• Stage 2 : Model Build
• Stage 3: Risk Assessment
• Stage 4: Assess Options & Design Development
15
DAP Process
| Social Media Dublin 201816
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
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
19
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
24
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
|25
INSPECTION PLANNING
SPECIMEN DESIGN & COSTING
CONDITION ASSESSMENT
SELECTION PROCESS
DETAILED DESIGN/DELIVERY
CONDITION ASSESSMENT
REGULATORY REPORTING
Sewer Rehabilitation Programme
26
Sewer Rehabilitation Prioritisation
1 Galway City D0050 SM29245901 SM29245903 C C 0 0 300 300 VC VC 05/07/2005 5 145.45 240 320 4.06 25 100 0 125 508
2 Galway City D0050 SM29245902 SM29245907 C C 0 0 375 375 VC VC 05/07/2005 5 40 240 720 4.06 25 100 0 125 507
3 Ramelton D0341 SC22212106 SC22212107 C C 0 0 225 225 PVC CO 16/05/2013 5 14.72 165 371 3.99 20 100 0 120 479
4 Enniscorthy D0029 SS97393503 SS97393510 C C 0 0 225 225 CO VC 20/08/2013 5 12.28 200 684 3.60 25 100 0 125 450
5 Enniscorthy D0029 SS97396902 SS97395901 C R 0 600 225 700 VC 02/10/2013 5 200 320 320 3.49 25 100 0 125 436
6 Ramelton D0341 SC22216105 SC22216101 C C 0 0 225 225 CO CO 02/07/2013 5 3.8 240 240 3.49 10 100 15 125 436
7 Ramelton D0341 SC22214003 SC22214101 C C 0 0 150 150 CO CO 13/05/2013 5 6.24 210 300 3.92 10 100 0 110 431
8 Carrigart D0523 SC12369401 SC12369502 C C 0 0 150 150 CO CO 20/02/2013 5 231.11 560 16640 3.89 10 100 0 110 427
9 Kilmacreannan D0513 SC14201302 SC14201401 C C 0 0 225 225 CO CO 09/04/2013 5 9.07 165 360 3.39 10 100 15 125 424
10 Downings D0350 SC09389210 SC09389203 C C 0 0 150 150 VC VC 19/09/2013 5 5.63 165 165 3.39 25 100 0 125 423
Capacity -
Infiltration
[WORKS]
DS height
(mm)
US pipe
material
Structural
Condition
US width
(mm)
DS width
(mm)
US height
(mm)
Structural
Mean Score
Structural
Peak Score
Structural
Total
Score
Agglomeration
DS
shape
ID
US node ID DS node ID
US
shape
ID
Drainage
Code
DS pipe
material
CCTV
Survey Date
TOTAL
LIKLIHOOD
SCORE -
WORKS
TOTAL RISK
SCORE -
WORKS
TOTAL
CONSEQUENCE
SCORE
Pipe
Material
[WORKS]
Structural
Condition
[WORKS]
Rank
29
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