regional wastewater treatment consolidation study phase 2 ... · workshop #3 –screen-out long ......
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Naugatuck Valley Council of Governments
Regional Wastewater Treatment Consolidation Study – Phase 2Workshop #3 – Screen-out Long List; Identify Short List Regional Alternatives
25 June 2020
Agenda
2
Introduction & Roles
Phase 1 - Long List Regional Alternatives
Develop & Screen Out Evaluations - Long List
Next Steps
Aggressive I/I
Conveyance Corridors
Plant Process and Site Layouts
Introduction & Roles
3
- NVCOG
- Black & Veatch
- Participating Communities
- OPM, DEEP
Phase 1 - Long List Regional Alternatives
4
Phase 1 – Long List Regional Alternatives
5
No. Alternative Description
1 Beacon Falls to Naugatuck
2 Beacon Falls to Seymour
2a Beacon Falls to Seymour, I/I Reduction
3 Derby to Ansonia
3a Derby to Ansonia, I/I Reduction
4 Derby to Ansonia, Effluent Pumped to Housatonic River
4a Derby to Ansonia, I/I Reduction, Effluent Pumped to Housatonic River
5 Derby and Seymour to Ansonia
5a Derby and Seymour to Ansonia, I/I Reduction
5b Derby and Seymour to Ansonia, Effluent Pumped to Housatonic River
5c Derby and Seymour to Ansonia, I/I Reduction, Effluent Pumped to Housatonic River
No. Alternative Description
6 Derby to Seymour and Ansonia
6a Derby to Seymour and Ansonia, I/I Reduction
8 Ansonia to Derby
8a Ansonia to Derby, I/I Reduction
9 Seymour and Ansonia to Derby
9a Seymour and Ansonia to Derby, I/I Reduction
10 Seymour to Ansonia, Part of Ansonia to Derby
10a Seymour to Ansonia, Part of Ansonia to Derby I/I Reduction
11 Beacon Falls and Seymour to Ansonia, Part of Ansonia to Derby
11a Beacon Falls and Seymour to Ansonia, Part of Ansonia to Derby, I/I Reduction
12 Beacon Falls, Seymour, and Ansonia to Derby
12a Beacon Falls, Seymour, and Ansonia to Derby, I/I Reduction
Methodology
Regional Alternatives were developed and screened out in a progression of three major steps (i.e. assessments):
1. Aggressive I/I Evaluation
• Review of extraneous flow reduction and feasibility of such measures
2. Conveyance Corridors Evaluation
• Feasibility of pipeline routes between communities
3. Plant Process and Site Layout Evaluation
• Treatment process upgrade and space requirements of regionalized plants
6
Aggressive I/I Evaluation
7
- I/I Programs – Overview
- I/I Programs Enacted at the Study Communities
- Aggressive I/I Programs – What Can Be Achieved?
- Regional Alternatives Screen Out
I/I Overview
• What is I/I and levels of control
• Identifying I/I
1. Flow monitoring
2. Major inflow sources
3. Infiltration sources
4. Sewer system evaluation surveys
8
Typical Sources of Inflow & Infiltration (I/I)
Wastewater Flow Analysis
Identifying Inflow Sources
I/I at the Study Communities
12
Derby Ansonia Seymour Beacon Falls Naugatuck
SSES (2016 – 2017)
No city-wide I/I program in
over 15 years
No city-wide I/I program in over
15 years
No need for aggressive I/I
SSES (2015 & 2017)
Phased I/I control plan (2019- Present and
beyond)
Re-procuring professional
O&M services (includes capital to
control I/I)
Derby Plant Flows 2015 – 2020
13
0.0
2.0
4.0
6.0
8.0
10.0
12.0
Jan-15 May-15 Oct-15 Feb-16 Jul-16 Dec-16 Apr-17 Sep-17 Jan-18 Jun-18 Nov-18 Mar-19 Aug-19 Dec-19
Flo
w R
ate
(MG
D)
Date
MAX
MIN
TOTAL
Ansonia Plant Flows 2015 – 2020
14
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Jan-15 May-15 Oct-15 Feb-16 Jul-16 Dec-16 Apr-17 Sep-17 Jan-18 Jun-18 Nov-18 Mar-19 Aug-19 Dec-19
Flo
w R
ate
(MG
D)
Date
MAX
MIN
TOTAL
Seymour Plant Flows 2015 – 2020
15
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Jan-15 May-15 Oct-15 Feb-16 Jul-16 Dec-16 Apr-17 Sep-17 Jan-18 Jun-18 Nov-18 Mar-19 Aug-19 Dec-19
Flo
w R
ate
(MG
D)
Date
MAX
MIN
TOTAL
Beacon Falls Plant Flows 2015 – 2018
16
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-16May-16 Jul-16 Sep-16 Nov-16 Jan-17 Mar-17May-17 Jul-17 Sep-17 Nov-17 Jan-18 Mar-18
Flo
w R
ate
(MG
D)
Date
MAX
MIN
TOTAL
Naugatuck Plant Flows 2015 – 2020
17
0
5
10
15
20
25
30
Jan-10 Sep-10 May-11 Jan-12 Sep-12 May-13 Jan-14 Aug-14 Apr-15 Dec-15 Aug-16 Apr-17 Dec-17 Aug-18 Apr-19 Dec-19
Flo
w R
ate
(MG
D)
Date
MAX
MIN
TOTAL
Aggressive I/I and Regional Alternatives Screen Out
Standard I/I Management
• Target reduction of peak flows
• Inflow and rapid infiltration are priority
• Point repairs or limited extents
• Focus on known/identified sources
Aggressive I/I Removal
• Target reduction of peak and average flows
• Comprehensive rehabilitation
• Removal of private I/I sources
18
Rehabilitation/Replacement Methods
Managing I/I from Private Laterals
Phase 1 – Long List of Regional Alternatives
21
No. Alternative Description
1 Beacon Falls to Naugatuck
2 Beacon Falls to Seymour
2a Beacon Falls to Seymour, I/I Reduction
3 Derby to Ansonia
3a Derby to Ansonia, I/I Reduction
4 Derby to Ansonia, Effluent Pumped to Housatonic River
4a Derby to Ansonia, I/I Reduction, Effluent Pumped to Housatonic River
5 Derby and Seymour to Ansonia
5a Derby and Seymour to Ansonia, I/I Reduction
5b Derby and Seymour to Ansonia, Effluent Pumped to Housatonic River
5c Derby and Seymour to Ansonia, I/I Reduction, Effluent Pumped to Housatonic River
No. Alternative Description
6 Derby to Seymour and Ansonia
6a Derby to Seymour and Ansonia, I/I Reduction
8 Ansonia to Derby
8a Ansonia to Derby, I/I Reduction
9 Seymour and Ansonia to Derby
9a Seymour and Ansonia to Derby, I/I Reduction
10 Seymour to Ansonia, Part of Ansonia to Derby
10a Seymour to Ansonia, Part of Ansonia to Derby I/I Reduction
11 Beacon Falls and Seymour to Ansonia, Part of Ansonia to Derby
11a Beacon Falls and Seymour to Ansonia, Part of Ansonia to Derby, I/I Reduction
12 Beacon Falls, Seymour, and Ansonia to Derby
12a Beacon Falls, Seymour, and Ansonia to Derby, I/I Reduction
Conveyance Corridors
22
- Reviewed Phase 1 Conveyance Corridors
- Initial Route Feasibility Review
- Developed Routes
- Evaluated Routes
Initial Route Feasibility Review
• Phase 1 routes were aligned along major infrastructure ROWs for ease of implementation
• ROW access almost impossible to obtain
23
Pipeline Routes Developed
• Development
• Routes were defined and analyzed using:
• Satellite Images
• Connecticut GIS Data
• Parcel Data
24
Physical Constructability Environmental
Length Topography Wetlands
Pipe Size Geology Flood Zones
Pump Stations Easements Protected Open Space
Beacon Falls to Naugatuck
25
ROUTE 1 ROUTE 2
Total Length (ft) 28,100 16,500
Pipeline10” to 12” gravity and force main
10” to 12” gravity and force main, and tunnel
Number of Pump Stations
5 3
Easements ~65% route along Naugatuck State Forest
~65% route along Naugatuck State Forest
Beacon Falls to Seymour
26
ROUTE 1 ROUTE 2
Total Length (ft) 31,000 26,500
Pipeline10” to 12” gravity and force main
10” to 12” gravity and force main, and tunnel
Number of Pump Stations
6 4
Easements ~5% route crosses private parcels
~45% route crosses private parcels
Seymour to Ansonia
27
ROUTE 1 MAIN ATTRIBUTES
Total Length (ft) 14,200
Pipeline14” to 18” gravity and force main
Number of Pump Stations
2
Easements ~10% route crosses private parcels
Ansonia to/from Derby
28
DERBY TO ANSONIA
ANSONIA TO DERBY
Total Length (ft) 8,100
Pipeline18” force main 16” to 18” gravity
and force main
Number of Pump Stations
1
Easements ~20% route crosses private parcels
Alternatives Screen-Out Based on Conveyance Corridors
29
No. Alternative Description
1 Beacon Falls to Naugatuck
2 Beacon Falls to Seymour
3 Derby to Ansonia
4 Derby to Ansonia, Effluent Pumped to Housatonic River
5 Derby and Seymour to Ansonia
5b Derby and Seymour to Ansonia, Effluent Pumped to Housatonic River
6 Derby to Seymour and Ansonia
8 Ansonia to Derby
9 Seymour and Ansonia to Derby
10 Seymour to Ansonia, Part of Ansonia to Derby
11 Beacon Falls and Seymour to Ansonia, Part of Ansonia to Derby
12 Beacon Falls, Seymour, and Ansonia to Derby
Plant Process and Site Layouts
30
- Plant Treatment and Process Evaluation:
1. 1. Flows and Loads Update
2. 2. Treatment Capacity Assessment
3. 3. Site Layouts
Flows and Loads Update – Derby, Ansonia & Seymour
• Flows and loads through design (2040) were updated from Phase 1
• Daily MOR (2018 through March 2020) was used
31
Design Flows Derby Ansonia Seymour
Annual Average (MGD) 1.9 1.9 1.3
Max. Month (MGD) 3.0 3.3 2.6
Peak Day (MGD) 5.5 5.0 4.5
Treatment Capacity Assessment
• Evaluated existing plants to handle individual and combined flows
• Assessment focused on:
• Footprint intensive processes - primary and secondary treatment
• Effluent requirements - tertiary treatment
• Treatment intensification selected for constrained plant sites
• Created plant facility layouts to meet treatment needs
32
Treatment Intensification
• Treatment intensification considered over conventional treatment due to limited footprint
33
Process Overview
Chemically Enhanced Primary Treatment (CEPT)
Allows the treatment of higher flows by increasing surface overflow rate
Ballasted Activated Sludge (BioMag)
Addition of magnetite (inert iron particles) to enhance settling
Integrated fixed film activated sludge (IFAS)
Use of plastic media to increase activated sludge inventory
Chemically Enhanced Primary Treatment (CEPT)
PrimarySludge
PrimaryEffluent
Coagulant Polymer
CEPT can increase primary clarifier capacity by approximately three times.
Primary Clarifier
RawInfluent
Chemically Enhanced
Conventional Activated Sludge (CAS)
• Activated sludge relies on bacterial growth to remove organics and nitrogen.
• Bioreactors and secondary clarifiers a single process when rating secondary capacity.
AX AE
PE SE
WAS
RAS
Fast Settling (Low SVI)
Poor Settling (High SVI)
Process Intensification Options
AX AE
PE SE
WAS
RAS
AX AE
PE SE
WAS
RAS
Recovered
Magnetite
Make-Up
Magnetite
BioMag™ increases settling rates in the clarifier.
Integrated Fixed Film Activated Sludge (IFAS) Ballasted Activated Sludge (BioMag™ by Evoqua)
IFAS increases active bacteria in bioreactor without increasing the solids loading to the clarifiers
Plant Site Layouts
37
- Base Case
- Regional alternatives
Derby – Base Case
38
Derby Plus Ansonia - Regional Alternatives
39
With BioMag With IFAS
Derby Plus Seymour - Regional Alternatives
40
With BioMag With IFAS
Derby Plus Ansonia & Seymour - Regional Alternatives
41
With BioMag With IFAS
Ansonia – Base Case
42
Ansonia Plus Derby - Regional Alternatives
43
Ansonia Plus Seymour - Regional Alternatives
44
Ansonia Plus Derby & Seymour - Regional Alternatives
45
Seymour Base Case or Seymour Plus Beacon Falls Regional Alternatives
46
Alternatives Screen-Out
47
No. Alternative Description
3 Derby to Ansonia
4 Derby to Ansonia, Effluent Pumped to Housatonic River
5 Derby and Seymour to Ansonia
5b Derby and Seymour to Ansonia, Effluent Pumped to Housatonic River
6 Derby to Seymour and Ansonia
8 Ansonia to Derby
9 Seymour and Ansonia to Derby
10 Seymour to Ansonia, Part of Ansonia to Derby
Next Steps
48
Short List of Regional Alternatives
49
No. Alternative Description
3 Derby to Ansonia
4 Derby to Ansonia, Effluent Pumped to Housatonic River
5 Derby and Seymour to Ansonia
5b Derby and Seymour to Ansonia, Effluent Pumped to Housatonic River
8 Ansonia to Derby
9 Seymour and Ansonia to Derby
10 Seymour to Ansonia, Part of Ansonia to Derby
Task 3 Look Ahead
1. Develop and evaluate short list regional alternatives
2. Compare short list regional wastewater alternatives
a) Non-cost criteria
b) Cost criteria
3. Recommend one or two regional alternatives for final development
50
23 RA
7 RA
1 RA
Thank you!