Regional Wastewater Treatment 25 June 2020 Consolidation Study - - PowerPoint PPT Presentation

Naugatuck Valley Council of Governments

Regional Wastewater Treatment Consolidation Study – Phase 2

Workshop #3 – Screen-out Long List; Identify Short List Regional Alternatives

25 June 2020

Agenda

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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

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• NVCOG
• Black & Veatch
• Participating Communities
• OPM, DEEP

Phase 1 - Long List Regional Alternatives

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Phase 1 – Long List Regional Alternatives

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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

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Aggressive I/I Evaluation

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• 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

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Typical Sources of Inflow & Infiltration (I/I)

Wastewater Flow Analysis

Identifying Inflow Sources

I/I at the Study Communities

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Derby Ansonia Seymour Beacon Falls Naugatuck SSES

(2016 – 2017)

No city-wide I/I program in

• ver 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

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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

Flow Rate (MGD) Date

MAX MIN TOTAL

Ansonia Plant Flows 2015 – 2020

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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

Flow Rate (MGD) Date

MAX MIN TOTAL

Seymour Plant Flows 2015 – 2020

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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

Flow Rate (MGD) Date

MAX MIN TOTAL

Beacon Falls Plant Flows 2015 – 2018

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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 Flow Rate (MGD) Date MAX MIN TOTAL

Naugatuck Plant Flows 2015 – 2020

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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

Flow Rate (MGD) 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

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Rehabilitation/Replacement Methods

Managing I/I from Private Laterals

Phase 1 – Long List of Regional Alternatives

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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

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• 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

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Pipeline Routes Developed

• Development
• Routes were defined and analyzed using:
• Satellite Images
• Connecticut GIS Data
• Parcel Data

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Physical Constructability Environmental Length Topography Wetlands Pipe Size Geology Flood Zones Pump Stations Easements Protected Open Space

Beacon Falls to Naugatuck

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ROUTE 1 ROUTE 2 Total Length (ft) 28,100 16,500 Pipeline 10” 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

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ROUTE 1 ROUTE 2 Total Length (ft) 31,000 26,500 Pipeline 10” 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

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ROUTE 1 MAIN ATTRIBUTES Total Length (ft) 14,200 Pipeline 14” to 18” gravity and force main Number of Pump Stations 2 Easements ~10% route crosses private parcels

Ansonia to/from Derby

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DERBY TO ANSONIA ANSONIA TO DERBY Total Length (ft) 8,100 Pipeline 18” 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

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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

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• 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

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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

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Treatment Intensification

• Treatment intensification considered over conventional treatment due to

limited footprint

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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)

Primary Sludge Primary Effluent

Coagulant Polymer

CEPT can increase primary clarifier capacity by approximately three times.

Primary Clarifier

Raw Influent

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

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• Base Case
• Regional alternatives

Derby – Base Case

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Derby Plus Ansonia - Regional Alternatives

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With BioMag With IFAS

Derby Plus Seymour - Regional Alternatives

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With BioMag With IFAS

Derby Plus Ansonia & Seymour - Regional Alternatives

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With BioMag With IFAS

Ansonia – Base Case

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Ansonia Plus Derby - Regional Alternatives

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Ansonia Plus Seymour - Regional Alternatives

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Ansonia Plus Derby & Seymour - Regional Alternatives

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Seymour Base Case or Seymour Plus Beacon Falls Regional Alternatives

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Alternatives Screen-Out

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• 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

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Short List of Regional Alternatives

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• 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

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23 RA 7 RA

1 RA

Thank you!