EPA/600/R-16/243 | December 2016 | www.epa.gov
United States
Environmental Protection
Agency
&EPA
Life Cycle Assessment and Cost
Analysis of Water and Wastewater
Treatment Options for Sustainability
Influence of Scale on Membrane
Bioreactor Systems
National Exposure Research Laboratory
National Risk Management Research Laboratory
Office of Research and Development
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*ERG
Life Cycle Assessment and Cost
Analysis of Water and Wastewater
Treatment Options for Sustainability:
Influence of Scale on Membrane
Bioreactor Systems
Sarah Cashman and Janet Mosley
Eastern Research Group, Inc.
110 Hartwell Ave
Lexington, MA 02421
Prepared for:
Cissy Ma, Jay Garland, Jennifer Cashdollar, Diana Bless
U.S. Environmental Protection Agency
National Exposure Research Laboratory
National Risk Management Research Laboratory
Office of Research and Development
26 W. Martin Luther King Drive
Cincinnati, OH 45268
December 19, 2016
EPA Contract No. EP-C-12-021
Work Assignment 3-41
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Although the information in this document has been funded by the United States Environmental
Protection Agency under Contract EP-C-12-021 to Eastern Research Group, Inc., it does not
necessarily reflect the views of the Agency and no official endorsement should be inferred.
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Abstract
ABSTRACT
Future changes in drinking and wastewater infrastructure need to incorporate a holistic
view of the water service sustainability tradeoffs and potential benefits when considering shifts
towards new treatment technology, decentralized systems, energy recovery and reuse of treated
wastewater. The main goal of this study is to determine the influence of scale on the energy and
cost performance of different transitional membrane bioreactors (MBR) in decentralized
wastewater treatment (WWT) systems by performing a life cycle assessment (LCA) and cost
analysis. LCA is a tool used to quantify sustainability-related metrics from a systems
perspective. The study calculates the environmental and cost profiles of both aerobic MBRs
(AeMBR) and anaerobic MBRs (AnMBR), which not only recover energy from waste, but also
produce recycled water that can displace potable water for uses such as irrigation and toilet
flushing. MBRs represent an intriguing technology to provide decentralized WWT services while
maximizing resource recovery. A number of scenarios for these WWT technologies are
investigated for different scale systems serving various population density and land area
combinations to explore the ideal application potentials. MBR systems are examined from 0.05
million gallons per day (MGD) to 10 MGD and serve land use types from high density urban
(100,000 people per square mile) to semi-rural single family (2,000 people per square mile). The
LCA and cost model was built with existing literature data sources, data from actual commercial
units, and wastewater treatment plant design costing software simulations. The results focus on
the energy demand and associated greenhouse gases (GHG) for the scenarios examined.
However, a full suite of life cycle impact assessment results, including water savings, was
calculated.
Net energy benefits, considering the drinking water displaced by the delivered recycled
water, start at the 1 MGD scale for the AeMBR and at the 5 MGD scale for the AnMBR operated
at 35°C (mesophilic). For all scales investigated, the psychrophilic AnMBR reactor operated at
20°C results in net energy benefits. This study supports the findings from other literature that
AnMBRs operated at lower reactor temperatures are a potential technology for decreasing the
environmental impacts of wastewater treatment systems. When examining the energy demand
results normalized to a cubic meter of water treated, all energy demand impacts decrease as the
scale increases due to economies of scales. While the AnMBR operating at ambient temperature
results in notable energy and GHG benefits compared to the AeMBR, the AnMBR costs remain
higher than the AeMBR under all scenarios. The main driver for this is the increase in operation
and maintenance labor needed to operate the anaerobic reactor and, to a lesser extent, anaerobic
reactor capital costs. The study found that all impacts decrease comparatively as the population
density increases due to decreased pumping distances and piping requirements, with the highest
burdens realized for the semi-rural single family land use and the greatest potential seen for the
high-density urban land use. Ambient temperature played a key role, with the most benefits and
least energy demand and GHG impacts from psychrophilic AnMBR operated in warm climate
conditions with combined heat and power generation from methane recovered from both the
headspace and the permeate.
While this study focused primarily on net energy demand and GHG impacts of the
decentralized MBR systems, there is a potential significant water savings from using recycled
wastewater. This study found that use of recycled water from decentralized MBR scenarios
avoids 0.94 to 0.96 cubic meters of drinking water per cubic meter of wastewater treated by
i
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Abstract
MBR. While AeMBRs are largely commercialized at the scales investigated, the data behind the
AnMBR model is based on bench-scale and pilot scale systems. As more full scale AnMBRs are
commissioned and operational data is better understood, the LCA model framework presented in
this work can be continually improved upon.
11
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Table of Contents
TABLE OF CONTENTS
Page
1.0 Introduction and Study Goal 1-1
2.0 Study Scope 2-1
2.1 Functional Unit 2-1
2.2 System Boundaries 2-1
2.3 Impact Assessment 2-4
2.4 Initial Data Sources 2-5
3.0 Methodology 3-1
3.1 Influent Water Quality and Quantity 3-1
3.2 Membrane Bioreactor Model 3-2
3.2.1 Aerobic MBR 3-2
3.2.2 Anaerobic MBR 3-7
3.3 Pre and Post Treatment Model 3-16
3.3.1 Preliminary Treatment (Screening and Grit Rem oval) 3-16
3.3.2 Fine Screening 3-17
3.3.3 Chlorination 3-18
3.4 Wastewater Collection System Model 3-20
3.4.1 Infrastructure Calculations 3-20
3.4.2 Operational Requirements 3-23
3.5 Recycled Water Delivery System 3-23
3.5.1 Infrastructure Calculations 3-24
3.5.2 Operational Requirements 3-25
3.5.3 Displacement of Drinking Water 3-26
3.6 Data Quality 3-29
4.0 Baseline Results 4-1
4.1 Detailed AeMBR Energy Results 4-1
4.2 Detailed AnMBR Energy Results 4-4
4.2.1 AnMBR Energy Results, 35°C Reactor Temperature 4-4
4.2.2 AnMBR Energy Results, 20°C Reactor Temperature 4-7
4.3 AeMBR Global Warming Potential Results 4-10
4.4 AnMBR Global Warming Potential Results 4-13
4.5 Energy Demand and Global Warming Potential Comparative Scenario
Analysis 4-18
4.6 Net Water Savings and other Potential Benefits 4-23
4.7 Cost Analysis Results 4-23
4.7.1 Cost Analysis Results for Aerobic MBR Wastewater Treatment
Plant 4-24
4.7.2 Cost Analysis Results for Anaerobic MBR Wastewater Treatment
Plant 4-25
4.7.3 Cost Analysis Results for Recycled Water Distribution System 4-28
4.7.4 Avoided Costs from Drinking Water Treatment and Distribution 4-30
in
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Table of Contents
TABLE OF CONTENTS (Continued)
Page
4.7.5 Combined AeMBR WWTP, Recycled Water Delivery System, and
Avoided DWT Cost Analysis Results 4-30
4.7.6 Combined AnMBR WWTP and Recycled Distribution System
Cost Analysis Results 4-33
4.7.7 Cost Comparative Scenario Analysis 4-36
5.0 Sensitivity Analyses 5-1
5.1 Climate and Methane Recovery Scenarios 5-1
5.1.1 Cumulative Energy Demand Results for Climate and Methane
Recovery Scenarios 5-6
5.1.2 Global Warming Potential Results for Climate and Methane
Recovery Scenarios 5-8
5.1.3 Cost Results for Climate and Methane Recovery Scenarios 5-10
5.2 Electrical Grid Mix 5-12
5.3 Displaced Drinking Water 5-14
6.0 Conclusions and Next Steps 6-1
7.0 References 7-1
Appendix A - Detailed Energy And Gwp Baseline Results
Appendix B - Full Baseline Lcia Results
Appendix C - Detailed Life Cycle Cost Analysis Results
Appendix D - Ambient And Influent Wastewater Temperature For Climate
Scenarios
Appendix E - Biogas Flaring and Recovery with CHP
iv
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List of Tables
LIST OF TABLES
Page
Table 1-1. Scale and Population Density Scenarios 1-1
Table 2-1. Life Cycle Impact Assessment Categories Used in the LCA Model 2-5
Table 2-2. Existing Data Sources for Main Foreground Processes 2-5
Table 3-1. Influent Water Quality Characteristics 3-1
Table 3-2. Primary Unit Processes and Sub-Processes in AeMBR Operation 3-3
Table 3-3. Life Cycle Inventory Operational Data for Aeration (AeMBR) 3-4
Table 3-4. Life Cycle Inventory Operational Data for Sludge Recycle Pumping (AeMBR) 3-4
Table 3-5. Life Cycle Inventory Operational Data for Scouring (AeMBR) 3-5
Table 3-6. Life Cycle Inventory Operational Data for Permeate Pumping (AeMBR) 3-5
Table 3-7. Life Cycle Inventory Operational Data for Waste Sludge Pumping (AeMBR) 3-5
Table 3-8. Life Cycle Inventory Infrastructure Data for Aeration (AeMBR) 3-6
Table 3-9. Life Cycle Inventory Infrastructure Data for Sludge Recycle Pumping
(AeMBR) 3-6
Table 3-10. Aerobic Membrane Bioreactor Tank Dimensions 3-7
Table 3-11. Life Cycle Inventory Infrastructure Data for Scouring (AeMBR) 3-7
Table 3-12. Life Cycle Inventory Infrastructure Data for Permeate Pumping (AeMBR) 3-7
Table 3-13. Life Cycle Inventory Infrastructure Data for Waste Sludge Pumping
(AeMBR) 3-7
Table 3-14. Life Cycle Inventory Operational Data for AnMBR at 35°C 3-9
Table 3-15. Life Cycle Inventory Operational Data for AnMBR at 20°C 3-10
Table 3-16. AnMBR Parameters Influencing Methane Generation for Municipal
Wastewater 3-10
Table 3-17. Life Cycle Inventory Infrastructure Data for Anaerobic Reactor 3-14
Table 3-18. Anaerobic Reactor Tank Dimensions 3-14
Table 3-19. Life Cycle Inventory Infrastructure Data for MBR Tanks (AnMBR) 3-14
Table 3-20. Life Cycle Inventory Infrastructure Data for Permeate Pumping (AnMBR) 3-15
Table 3-21. Life Cycle Inventory Infrastructure Data for Waste Sludge Pumping
(AnMBR) 3-15
Table 3-22. Anaerobic Membrane Bioreactor Tank Dimensions 3-15
Table 3-23. Life Cycle Inventory Operational Data for Preliminary Treatment 3-16
Table 3-24. Life Cycle Inventory Infrastructure Data for Preliminary Treatment 3-17
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List of Tables
LIST OF TABLES (Continued)
Page
Table 3-25. Life Cycle Inventory Operational Data for Fine Screening 3-17
Table 3-26. Life Cycle Inventory Infrastructure Data for Fine Screening 3-17
Table 3-27. Life Cycle Inventory Operational Data for Chlorination 3-18
Table 3-28. Life Cycle Inventory Infrastructure Data for Chlorination 3-19
Table 3-29. U.S. EPA Guidelines for Water Quality Standards for Unrestricted and
Restricted Urban Reuse 3-19
Table 3-30. Collection System Pipe Material by Diameter 3-21
Table 3-31. Collection System Pipe Lifetimes by Material Type 3-21
Table 3-32. Collection System Operational Requirements per Cubic Meter of Wastewater
Treated 3-23
Table 3-33. Recycled Water Delivery System Pipe Material by Diameter 3-24
Table 3-34. Recycled Water Delivery System Pipe Lifetimes by Material Type 3-24
Table 3-35. Total Meters of Recycled Water Delivery Pipe per Scenario 3-24
Table 3-36. Hazen-Williams Coefficients by Pipe Material 3-25
Table 3-37. Recycled Water Delivery Electricity Consumption per Scenario 3-26
Table 3-38. Recycled Water Delivered per Year and Associated Parameters by Scenario
Scale 3-27
Table 3-39. Displaced Drinking Water Treatment Impacts 3-29
Table 3-40. Cost Data Quality Criteria 3-30
Table 3-41. Life Cycle Inventory Data Quality Criteria 3-31
Table 4-1. Water Savings (m3 Water Consumed/m3 Wastewater Treated) 4-23
Table 4-2. Comparison of Sludge Output by AeMBR and AnMBR systems 4-23
Table 4-3. AnMBR Annual Energy Cost Differential between Operating at 35°C and
20 C 4-28
Table 4-4. Drinking Water Treatment and Distribution Costs Avoided by AeMBR WWT
and Recycled Water Delivery System 4-30
Table 4-5. Drinking Water Treatment and Distribution Costs Avoided by AnMBR WWT
and Recycled Water Delivery System 4-30
Table 5-1. Full and Abbreviated Names of Climate and Methane Recovery Scenarios and
Associated Differentiating Parameters 5-2
Table 5-2. eGRID 2012 Resource Mix by Subregion 5-12
Table 5-3. Global Warming Potential Results for Electrical Grid Sensitivity Analysis (kg
C02 eq per Year) 5-13
vi
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List of Tables
LIST OF TABLES (Continued)
Page
Table 5-4. Literature Values for Electricity Consumption for Drinking Water Production
and Delivery 5-15
vii
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List of Figures
LIST OF FIGURES
Page
Figure 2-1. System Boundaries for AeMBR Analysis 2-3
Figure 2-2. System Boundaries for AnMBR Analysis 2-4
Figure 3-1. AeMBR Sub Processes 3-3
Figure 3-2. AnMBR Sub Processes (Adapted from Feickert et al. 2012) 3-9
Figure 3-3. Total Meters of Sewer Pipe by Scenario on the Basis of People Served 3-21
Figure 3-4. Total Meters of Sewer Pipe by Scenario on the Basis of People per Square
Mile 3-22
Figure 3-5. Meters of Sewer Pipe by Scenario Normalized to Cubic Meters of Water
Treated and on the Basis of People Served 3-22
Figure 3-6. Meters of Sewer Pipe by Scenario Normalized to Cubic Meters of Water
Treated and on the Basis of People per Square Mile 3-23
Figure 3-7. System Boundaries of Drinking Water Treatment 3-28
Figure 4-1. AeMBR Cumulative Energy Demand Results (MJ/Year) 4-2
Figure 4-2. AeMBR Cumulative Energy Demand Results (MJ/m3 Wastewater Treated) 4-3
Figure 4-3. AnMBR, 35°C Reactor Temperature, Cumulative Energy Demand Results
(MJ/Year) 4-5
Figure 4-4. AnMBR, 35°C Reactor Temperature, Cumulative Energy Demand Results
(MJ/m3 Wastewater Treated) 4-6
Figure 4-5. AnMBR, 20°C Reactor Temperature, Cumulative Energy Demand Results
(MJ/Year) 4-8
Figure 4-6. AnMBR, 20°C Reactor Temperature, Cumulative Energy Demand Results
(MJ/m3 Wastewater Treated) 4-9
Figure 4-7. AeMBR Global Warming Potential Results (kg CO2 eq/Year) 4-11
Figure 4-8. AeMBR Global Warming Potential Results (kg CO2 eq/m3 Wastewater
Treated) 4-12
Figure 4-9. AnMBR, 35°C Reactor Temperature, Global Warming Potential Results (kg
CO2 eq/Year) 4-14
Figure 4-10. AnMBR, 20°C Reactor Temperature, Global Warming Potential Results (kg
CO2 eq/Year) 4-15
Figure 4-11. AnMBR, 35°C Reactor Temperature, Global Warming Potential Results (kg
CO2 eq/ m3 Wastewater Treated) 4-16
Figure 4-12. AnMBR, 20°C Reactor Temperature, Global Warming Potential Results (kg
CO2 eq/ m3 Wastewater Treated) 4-17
viii
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List of Figures
LIST OF FIGURES (Continued)
Page
Figure 4-13. AeMBR and AnMBR Energy Demand Comparison for Multi Family Land
Use (MJ/Year) 4-19
Figure 4-14. AeMBR and AnMBR Energy Demand Comparison for Multi Family Land
Use (MJ/m3 Wastewater Treated) 4-20
Figure 4-15. AeMBR and AnMBR Global Warming Potential Comparison for Multi
Family Land Use (kg CO2 eq/Year) 4-21
Figure 4-16. AeMBR and AnMBR Global Warming Potential Comparison for Multi
Family Land Use (kg CO2 eq/m3 Wastewater Treated) 4-22
Figure 4-17. Yearly Expenses for AeMBR Facility by Scale 4-24
Figure 4-18. Expenses for AeMBR Facility by Scale per m3 Wastewater Treated 4-25
Figure 4-19. Yearly Expenses for the 35°C AnMBR Facility by Scale 4-26
Figure 4-20. Yearly Expenses for the 20°C AnMBR Facility by Scale 4-26
Figure 4-21. Expenses for the 35°C AnMBR Facility by Scale per m3 Wastewater Treated.... 4-27
Figure 4-22. Expenses for the 20°C AnMBR Facility by Scale per m3 Wastewater Treated.... 4-28
Figure 4-23. Yearly Life Cycle Costs for Recycled Water Delivery System for Each
Density Scenario Associated with the 0.05 and 0.1 MGD Scales 4-29
Figure 4-24. Yearly Life Cycle Costs for Recycled Water Delivery System for Each
Density Scenario Associated with the 1, 5, and 10 MGD Scales 4-29
Figure 4-25. Combined Annual AeMBR, Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD Scales 4-31
Figure 4-26. Combined Annual AeMBR, Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD Scales 4-32
Figure 4-27. Combined AeMBR, Recycled Water Delivery, and Avoided DWT Costs for
Each Density and Scale Scenario per m3 of Treated Wastewater 4-32
Figure 4-28. Combined Annual AnMBR (35 °C), Recycled Water Delivery, and Avoided
DWT Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD
Scales 4-33
Figure 4-29. Combined Annual AnMBR (35 °C), Recycled Water Delivery, and Avoided
DWT Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD
Scales 4-34
Figure 4-30. Combined AnMBR (35 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density and Scale Scenario per m3 of Treated Wastewater 4-34
Figure 4-31. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD Scales 4-35
IX
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List of Figures
LIST OF FIGURES (Continued)
Page
Figure 4-32. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD Scales 4-35
Figure 4-33. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density and Scale Scenario per m3 of Treated Wastewater 4-36
Figure 4-34. Comparative Yearly MBR Costs for Multi Family Land Use Scenario 4-37
Figure 4-35. Comparative MBR Costs per m3 of Treated Wastewater for Multi Family
Land Use Scenario 4-37
Figure 5-1. Detailed Cumulative Energy Demand Results for AnMBR Climate and
Methane Recovery Scenarios 5-7
Figure 5-2. Detailed Global Warming Potential Results for AnMBR Climate and
Methane Recovery Scenarios 5-9
Figure 5-3. Detailed Cost Results for AnMBR Climate and Methane Recovery Scenarios 5-11
Figure 5-4. Global Warming Potential Results for Electrical Grid Sensitivity Analysis (kg
CO2 eq per m3 Wastewater Treated) 5-14
Figure 5-5. Range of Electricity Consumption Reported in Literature for Drinking Water
Treatment Stages 5-16
Figure 5-6. Global Warming Potential Results for Displaced Drinking Water Treatment
Sensitivity Analysis for all Considered Scenarios 5-17
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List of Acronyms
LIST OF ACRONYMS
AeMBR
Aerobic Membrane Bioreactor
AnMBR
Anaerobic Membrane Bioreactor
BOD
Biological Oxygen Demand
CEPCI
Chemical Engineering Plant Cost Index
CFU
Colony Forming Units
CHP
Combined Heat and Power
COD
Chemical Oxygen Demand
DWT
Drinking Water Treatment
EPS
Expanded Polystyrene
GCWW
Greater Cincinnati Water Works
HRT
Hydraulic Retention Time
LCA
Life Cycle Assessment
LCC
Life Cycle Cost Assessment
LCI
Life Cycle Inventory
LCIA
Life Cycle Impact Assessment
MBR
Membrane Bioreactor
MGD
Million Gallons per Day
MLSS
Mixed-Liquor Suspended Solids
MSDGC
Metropolitan Sewer District of Greater Cincinnati
NTU
Nephelometric Turbidity Units
ORD
U.S. EPA's Office of Research and Development
PFAS
Plug Flow Activated Sludge Diffused Aeration Reactor
PVDF
Polyvinylidene Fluoride
SSWR
Safe and Sustainable Water Resources Program
SRT
Solids Retention Time
TKN
Total Kjeldahl Nitrogen
TRACI
Tool for the Reduction and Assessment of Chemical and Environmental Impacts
vss
Volatile Suspended Solids
WWT
Wastewater Treatment
WWTP
Wastewater Treatment Plant
XI
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1.0—Introduction and Study Goal
1.0 Introduction and Study Goal
The Office of Research and Development's (ORD), Safe and Sustainable Water
Resources (SSWR) Program, is the principal research lead seeking metrics and tools to compare
the tradeoffs between economic, human health, and environmental aspects of current and future
municipal water and wastewater services. Changes in drinking water and wastewater
management have typically resulted from new regulations, which focus on developing and
implementing additions to the current treatment and delivery schemes. However, these additions
are undertaken in the absence of a system's holistic view and can result in transferring issues
from one problem area to another. Future alternatives need to address the whole water services
physical system to aid in the provision of more sustainable water services such that water
scarcity is alleviated. Furthermore, these sustainable systems must be based on overall resource
recovery (water, energy, nutrients, etc.). Therefore, a range of integrated metrics and tools need
to be used to evaluate the multifaceted solutions and identify "next-generation" sustainable
municipal water and wastewater systems, as well as to identify possible regulatory/policy steps
to facilitate this evolution. This study offers quantitative environmental and cost data from a
systems perspective for transitional "next generation" decentralized wastewater (WWT)
technologies.
The main goal of this study is to determine the influence of scale on the energy and cost
performance of different membrane bioreactors (MBR) in wastewater mining systems as
transitional technology by performing a life cycle assessment (LCA) and cost analysis. LCA is a
tool used to quantify sustainability-related metrics from a systems perspective. The study
calculates the environmental and cost profile of both aerobic MBRs (AeMBR) and anaerobic
MBRs (AnMBR). MBRs represent an intriguing technology to provide decentralized WWT
services. A number of scenarios for these WWT technologies are investigated for different scale
systems serving various population density and land area combinations, assuming 100 gallons of
wastewater generated per person per day (WaterSense and U.S. EPA, 2016). All scenarios
considered are illustrated in Table 1-1. A total of 18 scale and density scenarios are modeled.
Table 1-1. Scale and Population Density Scenarios
Land Use
Type
0.05MGD
(500 ppl
served)
0.1MGD
(1,000 ppl
served)
1MGD
(10,000 ppl
served)
5MGD
(50,000 ppl
served)
10MGD
(100,000 ppl
served)
100,000
#|)|)l/sqm
High density
urban
0.005 sqm
0.01 sqm
0.1 sqm
0.5 sqm
1 sqm
50,000
#|)|)l/sqm
Multi family
0.01 sqm
0.02 sqm
0.2 sqm
1 sqm
2 sqm
10,000
#])pl/sqm
Single family
0.05 sqm
0.1 sqm
1 sqm
5 sqm
10 sqm
2,000
#ppl/sqm
Semi-rural
single family
0.25 sqm
0.5 sqm
5 sqm
N/A
N/A
sqm = square mile; ppl = people; MGD = million gallons per day
1-1
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2.0—Study Scope
2.0 Study Scope
This section covers the project scope necessary to meet the study's goals.
2.1 Functional Unit
A functional unit provides the basis for results comparison in an LCA. The key
consideration in developing a functional unit is to ensure all systems are compared on an
equivalent performance basis. The functional unit used in this study is based on providing WWT
service to a specified number of people. The study considers the following number of people per
service area of varying density (as laid out in Table 1-1): 500, 1,000, 10,000, 50,000, and
100,000. Only wastewater from households is incorporated in the study boundaries (e.g.
wastewater from commercial buildings and industrial facilities as well as storm water is
excluded). While AeMBR and AnMBR technologies are mainly compared on an annual basis of
wastewater treated, results are normalized to a specified volume of wastewater treated (one cubic
meter (m3)) in order to assess the relative performance of a technology across different scales.
2.2 System Boundaries
All scenarios examined are considered theoretical U.S. decentralized wastewater
treatment systems. For the MBR technologies examined, the system boundary starts at collection
of wastewater and ends at downstream use of the recycled water. The system boundaries for the
AeMBR analysis are illustrated in Figure 2-1, and the system boundaries for the AnMBR are
presented in Figure 2-2. The AeMBR and AnMBR treatment systems are modeled as transitional
"plug-in" systems, which explore sewer mining for energy recovery and divert wastewater that
otherwise goes through the conventional activated sludge system in a centralized wastewater
treatment plant (WWTP). The systems use existing wastewater collection infrastructure and
sludge handling processes. The wastewater collection system in this study is modeled as a
gravity sewer system, as is the case for the Metropolitan Sewer District of Greater Cincinnati
(MSDGC), the existing plant assumed to handle the sludge discharged from the MBR treatment
processes. The collection system is modeled equivalently for the AeMBR and AnMBR systems,
but varies by the different population density scenarios. The avoided drinking water treatment
and distribution is modeled based on a previously completed LCA for Greater Cincinnati Water
Works.
Prior to treatment via MBR, the wastewater goes through a coarse screening and grit
removal stage followed by fine screening. Coarse screening removes large debris from the
wastewater flow through multiple screens. Grit removal extracts stone, grit, and other settleable
debris. It is assumed debris from this stage is transported to a nearby landfill. Fine screening with
mesh size 2 mm or smaller is important to prevent membrane fouling (Jeffery, 2005; U.S.EPA,
2007). The wastewater then undergoes treatment via MBRs. MBR combines biological treatment
with solids removal via filtration (U.S. EPA, 2007). Biological treatment for the AeMBR is
carried out in a plug flow activated sludge diffused aeration reactor, and an anaerobic reactor is
the biological treatment method for AnMBR. In the baseline model, the AnMBR system includes
electricity generation using the resulting biogas, reducing the need for purchased electricity. In
some cases, more electricity is produced than required by the AnMBR system, resulting in a net
electricity displacement credit. A sensitivity analysis presented in Section 5.0 examines the effect
of using biogas for combined heat and power (CHP) operations. CHP generates electricity and
utilizes the waste heat from combusting biogas to displace natural gas inputs for influent heating.
2-1
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2.0—Study Scope
This sensitivity analysis includes an additional "worst case" scenario in which the biogas is
flared and no energy is recovered.
The filter portion of the MBR is made of thousands of hollow fibers grouped into bundles
and attached on the top and bottom in a frame called a module. Up to 48 modules are inserted
into a larger frame called a cassette that is installed inside the reactor. Each hollow fiber has
many microscopic pores that allow water to be drawn by a vacuum through the membrane into
the inside of the fiber while blocking passage of solids and microbial biomass. The filtered
water, or permeate, is then drawn out of the hollow fiber and sent to post-treatment. As with any
filter, the membrane must be regularly cleaned in order to dislodge solids from the membrane
pores and surfaces to allow permeate to flow through and prevent biofilm built-up. In the
AeMBR system, the membrane is scoured by large air bubbles that rise up from the bottom of
the tank and remove fouling on the membrane fibers. In the AnMBR systems, the membrane is
scoured by rising bubbles of biogas. The membrane pores are cleaned periodically by membrane
relaxation when the effluent vacuum pump that pulls permeate through the pores turns off
briefly, allowing solids to fall away from the membrane. Lastly, membrane pores are cleaned
with a periodic backflush of sodium hypochlorite (NaOCl).
For all scenarios, the remaining sludge after MBR treatment is discharged to the existing
sewer for solids handling at the centralized WWTP. This study makes the simplifying
assumption the centralized WWTP is large enough and the operation of the transitional treatment
systems and any variations in waste returned to the sewer would have a negligible effect on the
operations of the centralized WWTP. The WWTP in the MSDGC baseline scenario treats 114
million gallons per day (MGD), which is a much greater scale than the MBR systems
investigated (see Table l-l).1 Therefore, treatment of the sludge from the MBRs is considered to
be outside the system boundaries. It should be noted that more solids would be returned after
treatment in the AeMBR as compared to the AnMBR as more of the waste is converted to
methane and water in the anaerobic scenario, but this marginal difference in downstream
centralized WWTP is considered insignificant here.
The effluent from the MBR systems then goes through a chlorination step with sodium
hypochlorite to disinfect the recycled water to a condition that is suitable for use for a variety of
purposes. The delivery of the recycled water to the use point includes the associated
infrastructure and energy requirements for a pressurized distribution system. Similar to the
infrastructure for the collection system, the recycled water infrastructure depends on the
population density scenario and scale. Recycled water can be used for non-potable purposes such
as toilet flushing, landscape irrigation, cooling towers, car washing, and other uses depending on
the effluent quality and quantity. In this study, recycled water quality is not expected to comply
with standards for drinking water used for human consumption. As a "worst case" scenario, this
study assumes all recycled water returns to the same user who produced the wastewater, as
opposed to use of the recycled water at a point closer to the facility such as a nearby park or golf
course. In all cases, the use of recycled water is assumed to replace the equivalent quantity of
potable water produced in Cincinnati (Cashman et al., 2014a). The baseline Cincinnati water
treatment scheme is displayed in the large blue box in Figure 2-1 and Figure 2-2. The baseline
water treatment system is based on the Greater Cincinnati Water Works (GCWW), Richard
1 The baseline WWTP is modeled based on the MSDGC Mill Creek Plant for the year 2012.
2-2
-------
2.0—Study Scope
Miller Treatment Plant. The data in the GCWW model is representative of the year 2011, in
which 106 MGD of potable water were produced.
Household Wastewater
Source Water, River
Acquisition
Population
Density .
Collection, Gravity
Sewer System
Alum Coagulant
and Coagulant Aid
Production
Flocculation
Coarse Screening,
Grit Removal, and
Fine Screening
Disposal of
Sedimentation
Screenings and Grit to Landfill
Sedimentation
Filtration
G ra n u la r Act ivated
Carbon Production
Sludge to Municipal WWTP
Capacity
Adsorption
G ra n u la r Act ivated
Carbon
Regeneration
Chlorination with
Sodium
Hypochlorite
Conditioning
Transportation Included
(If Applicable)
Primary
Disinfection,
Gaseous Chlorine
Transportation Excluded
Recycled Water
Delivery System
Primary Input/
Final Demand
Fluoridation
Distribution
Use of Recycled Water
Displaced Primary Input/
Final Demand
Displaced Process
Use of Potable Water
Displaced Potable Water Treatment
from Surface Water
Parameter to Vary
Figure 2-1. System Boundaries for AeMBR Analysis
2-3
-------
2.0—Study Scope
Wastewater
Collection, Gravity
Sewer System
Population*
Density
Alum Coagulant
and Coagulant Aid
Production
Coarse Screening,
Grit Removal, and
Fine Screening
Disposal of
Sedimentation
Waste
Screenings and Grit to Landfill 4-
Sedimentation
Electricity from
Microturbine
Filtration
Granular Activated
Carbon Production
Capacity
'Natural Gas
for Heat
Adsorption
Granular Activated
Carbon
Regeneration
Sludge to Municipal WWTP
Chlorination with
Sodium
Hypochlorite
Conditioning
Transportation Included
(If Applicable)
Primary
Disinfection,
Gaseous Chlorine
Transportation Excluded
Primary Input/
Final Demand
Recycled Water
Delivery System
Fluoridation
WWT Process
Displaced Primary Input/
Final Demand
Distribution
Displaced Process
Use of Potable Water
Parameter to Vary
Displaced Potable Water Treatment
from Surface Water
Asterisk {*) indicates processes that are
only included in the sensitivity analysis
Figure 2-2. System Boundaries for AnMBR Analysis
2.3 Impact Assessment
Table 2-1 summarizes the complete list of impacts examined for the LCA model runs.
This study addresses global, regional, and local impact categories. The life cycle impact
assessment (LCIA) method provided by the Tool for the Reduction and Assessment of Chemical
and environmental Impacts (TRAGI), version 2.1, developed by the U.S. EPA specifically to
model environmental and human health impacts in the U.S., is the primary LCIA method applied
in this work (Bare et al. 2002). Additionally, the ReCiPe LCIA method is used to characterize
fossil fuel depletion and blue water use (Goedkoop et al., 2008). Energy is tracked based on
point of extraction using the cumulative energy demand method developed by ecoinvent
(Ecoinvent Centre, 2010a). While the full suite of indicators identified in Table 2-1 are
summarized in this report, the overall focus of the results discussion is energy demand and global
warming potential. A companion cost analysis is conducted. The emphasis of the cost analysis is
to understand the contribution of life cycle stages to the overall cost of treating the wastewater.
2-4
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2.0—Study Scope
Table 2-1. Life Cycle Impact Assessment Categories
Used in the LCA Model
Impact Category
Methodology
Unit
Acidification
TRACI 2.1
kg SOi-eq (equivalent)
Ecotoxicity
TRACI 2.1
CTU
Eutrophication
TRACI 2.1
kg N-eq
Global wanning
TRACI 2.1
kg C02-eq
Human health criteria
TRACI 2.1
PMlO-eq
Human health toxicity - cancer
TRACI 2.1
CTU (comparative
toxic units)
Human health toxicity - non-cancer
TRACI 2.1
CTU
Ozone depletion
TRACI 2.1
kg CFC-11 eq
Smog
TRACI 2.1
kg Ch-cq
Cumulative energy demand
Ecoinvent
MJ-eq
Fossil depletion
ReCiPe (H)
kg oil-eq
Water depletion
ReCiPe (H)
m3
2.4 Initial Data Sources
This study largely relies upon existing data sources and CAPDETWorks™ Version 3.0,2
a wastewater treatment design and costing software, to build the LCA models and cost analysis.
The primary data sources for the main foreground processes in this analysis are listed in Table
2-2. If existing foreground data sources were not available for all MBR scenarios, the project
team either (1) attempted to contact manufacturers to collect additional data or (2) derived
required process inputs from publicly available equipment specifications on the manufacturer's
website. As discussed in Section 1.0, certain baseline Cincinnati WWT and drinking water
treatment (DWT) processes are incorporated into this analysis. These LCA processes were
created for Cincinnati in a previous EPA project "Life Cycle Environmental and Economic
Assessment of the Water and Wastewater Systems in Cincinnati" (Cashman et al., 2014a;
2014b). Upstream processes use information from the National Renewable Energy Laboratory's
U.S. Life Cycle Inventory Database (U.S. LCI), a publicly available life cycle inventory source
(NREL, 2012). Where upstream data were not available from the U.S. LCI, ecoinvent v2.2, a
private Swiss LCI database with data for many unit processes, is used (Ecoinvent Centre,
2010b).
Table 2-2. Existing Data Sources for Main Foreground Processes
LCA Model Component
Existing Data Sources
Aerobic MBR
CAPDETWorks Version 3.0 (wastewater treatment design and costing software)
Simulations; University of Michigan MBR LCA study (Smith et al., 2014) and other
literature sources
Correspondence with GE (manufacturers of AeMBRs, GE ZeeWeed® 500D hollow
fiber membranes using LEAPmbr Aeration Technology)
Anaerobic MBR
Energy balance equations from Feickert et al. (2012), literature sources on existing
pilot and lab-scale systems, and University of Michigan MBR LCA study (Smith et
al., 2014)
2 Software developed by Hydromantis Environmental Software Solutions, Inc.
http://www.hYdromantis.com/CapdetWorks.html (Accessed 6/26/16)
2-5
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2.0—Study Scope
Table 2-2. Existing Data Sources for Main Foreground Processes
LCA Model Component
Existing Data Sources
Correspondence with GE (manufacturers of AnMBRs, GE ZeeWeed® 500D hollow
fiber membranes using LEAPmbr Aeration Technology)
Collection System
Infrastructure
Cincinnati municipal wastewater treatment LCA completed by the U.S. EPA
(Cashman et al., 2014b); Length calculation estimations from water infrastructure
expert at PG Environmental, LLC (Rowlett, 2015)
Recycled Water Delivery
System
Cincinnati municipal drinking water treatment LCA completed by the U.S. EPA
(Cashman et al., 2014a); Length calculation estimations from water infrastructure
expert at PG Environmental, LLC (Rowlett, 2015)
Displacement of Drinking
Water Treatment
Cincinnati municipal drinking water treatment LCA completed by the U.S. EPA
(Cashman et al., 2014a)
2-6
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3.0—Methodology
3.0 Methodology
This section covers the methodology utilized to develop the life cycle inventory (LCI) for
this study. The LCI data modules were constructed, in accordance with ISO 14040: 2006
recommendation, to include the following information:
Elementary inputs and outputs (to and from nature)
• Raw material inputs required;
• Air emission outputs; and
• Waterborne emission outputs.
Intermediate inputs and outputs (to and from the technosphere)
• Energy product inputs required;
• Economic goods (material) input required;
• Solid waste outputs to be managed; and
• Economic goods (material) output.
All LCI unit processes were built in the open-source LCA software OpenLCA version
1.4.2.3
3.1 Influent Water Quality and Quantity
The influent water quality characteristics assumed for all scenarios in this study are
displayed in Table 3-1. This data is representative of medium strength municipal wastewater
from individual residences (Metcalf and Eddy, 2014). The average summer and winter
temperatures are based on the U.S. as a whole and, along with pH, cation, and anion
concentration, are taken from CAPDETWorks default values.
Table 3-1. Influent Water Quality Characteristics
Description
Value
U nits
Suspended Solids
195
mg/L
% Volatile Solids
78
%
BOD
200
mg/L
Soluble BOD
80
mg/L
COD
508
mg/L
Soluble COD
177
mg/L
TKN
35
mgN/L
Soluble TKN
22.4
mgN/L
Ammonia
20
mgN/L
Total Phosphorus
5.6
mgP/L
pH
7.6
Cations
160
mg/L
3 Software developed by GreenDelta GmbH, http://www.openlca.org/openlca (Accessed 6/26/16)
3-1
-------
3.0—Methodology
Table 3-1. Influent Water Quality Characteristics
Description
Value
U nits
Anions
160
mg/L
Settleable Solids
10
mL/L
Oil and Grease
76
mg/L
Nitrite
0
mgN/L
Nitrate
0
mgN/L
Non-Degradable Fraction of
Volatile Suspended Solids
(VSS)
48
%
Biodegradable VSS
52
%
Average Summer3
23
degC
Average Winter3
10
degC
a Applicable only for the AeMBR system.
The AnMBR model varies slightly, based on available pilot scale research for modeling
these systems. The average influent temperature for the AnMBR is assumed to be 20°C and the
average ambient temperature is assumed to be 21.5°C (Feickert et al., 2012). Since this study
investigates a transitional system using sewer mining concepts, diurnal and seasonal variation in
influent water quantity is not considered in the baseline results. However, modeling of different
ambient and influent temperatures for the AnMBR is conducted in the sensitivity analyses in
Section 5.0. The amount of water withdrawn from the sewer would be controlled such that any
water flow in the sewer beyond the capacity of the MBR treatment facility would bypass the
MBR facility and continue down the sewer to the centralized WWTP. One additional MBR
treatment train is included in each scenario to allow for operation at full capacity during periodic
cleanings of each MBR treatment train.
3.2 Membrane Bioreactor Model
The modules used to build the AeMBR and AnMBR LCI are provided in this section.
3.2.1 Aerobic MBR
The aerobic MBR model is primarily based on modeling simulations in
CAPDETWorks™ design and costing software, with the sub processes of AeMBR identified in
Figure 3-1. A general description of coarse screening, grit removal, fine screening, and
chlorination steps is found in Section 2.2, and detailed modeling methodology for these
processes is provided in Section 3.3. This section focuses on the modeling for the membrane
bioreactor with a plug flow activated sludge diffused aeration reactor (PFAS).
3-2
-------
3.0 Methodology
AeMBR Subprocesses
Effluent to
Chlorination
with Sodium
Hypochlorite
Influent
from Fine
Screening
Sludge
Discharged
to Sewer
Note: Each sub process
includes purchased
electricity as an input
Sludge
Recycle
Pumping
Permeate
Pumping
Scouring
Waste Sludge
Pumping
Aerobic
Membrane
Bioreactor
Plug Flow
Activated Sludge
Diffused Aeration
Figure 3-1. AeMBR Sub Processes
It is assumed the membrane technology used is the GE ZeeWeed® 500D hollow fiber
membranes using LEAPmbr Aeration Technology. Table 3-2 lists the primary unit processes and
related sub-processes and Table 3-3 through Table 3-7 show the LCI data for AeMBR operation,
excluding pre- and post-treatment steps (the modeling of these steps is shown in Section 3.3).
Life cycle costs are based on CAPDETWorks modeling unless otherwise noted.
Table 3-2. Primary Unit Processes and Sub-Processes
in AeMBR Operation
Unit Process
Sub-Process
Plug Flow Activated Sludge with MBR
Aeration
Plug Flow Activated Sludge with MBR
Sludge Recycle Pumping
Membrane Bioreactor
Scouring
Membrane Bioreactor
Permeate Pumping
Membrane Bioreactor
Waste Sludge Pumping
The PFAS model used CADPETWorks default input parameters except for process
design choice of carbon removal only instead of carbon removal plus nitrification, since nutrient
removal is not included in this study. Nutrient removal is not included in order to focus on MBR
technology differences and because nutrient removal is not always required for end uses or
recycled water considered in this study. The CAPDETWorks model estimated the same amount
of annual electricity required for the 0.05 MGD PFAS as the 0.1 MGD PFAS. The linear least
3-3
-------
3.0—Methodology
squares method was used to find a best-fit line for electricity demand for the 0.1-10 MGD
systems and to extrapolate electricity use per year for the 0.05 MGD PFAS.
Table 3-3. Life Cycle Inventory Operational Data for Aeration (AeMBR)
Water Output
(MGD)
Electricity
(kWh/vr.)
0.05 MGD
0.050
55,100
0.1 MGD
0.10
69,300
1 MGD
1.00
277,000
5 MGD
5.00
1,390,000
10 MGD
10.0
2,630,000
Table 3-4. Life Cycle Inventory Operational Data for Sludge Recycle Pumping (AeMBR)
Water Output
(MGD)
Electricity
(kWh/vr.)
0.05 MGD
0.050
5,050
0.1 MGD
0.10
10,100
1 MGD
1.00
100,000
5 MGD
5.00
499,000
10 MGD
10.0
997,000
The following modifications were made to the default CAPDETWorks input parameters
to model the membrane bioreactor as representative of GE ZeeWeed 500D hollow fiber
membranes with LEAPmbr Aeration Technology:
• Specific scour air demand - changed from 0.30 to 0.15 Nm3/(m2hr) based on GE
documentation reporting that a switch from 10/10 sequential aeration (default settings
in CAPDETWorks) to 10/30 eco-aeration could reduce air demand by up to 50% and
an upgrade from 10/30 sequential aeration to LEAPmbr aeration can reduce air
demand by an additional 30% (Kicsi, 2014). A study by GE found an average air
scouring flow rate of 0.12 Nm3/(m2hr) using the ZeeWeed 500D membranes as of
2010 (Cote et al. 2012). Brochures and presentations published by the manufacturer
suggest a 30-70%) reduction in air and associated energy required for aeration as
compared to the 10/10 sequential aeration used as the default in CAPDETWorks
MBR model (GE Power and Water, 2014; Kicsi, 2014). A specific air demand of 0.15
Nm3/(m2hr) was chosen for the CAPDETWorks input parameter (50% of the default
setting) as it is the middle of the range of expected reductions in air demand between
10/10 sequential aeration and LEAPmbr aeration technology.
• Physical cleaning interval - changed from 9 minutes to 10 minutes of membrane
relaxation (Graham Best, GE Power, and Water Regional Sales Manager, personal
communication, February 27, 2015).
• Physical cleaning duration - changed from 60 seconds to 45 seconds (Graham Best,
GE Power, and Water Regional Sales Manager, personal communication, February
27, 2015).
3-4
-------
3.0—Methodology
• Chemical cleaning interval - changed from 168 hours to 84 hours for biweekly
membrane cleaning with sodium hypochlorite only (Graham Best, GE Power, and
Water Regional Sales Manager, personal communication, February 27, 2015).
• Backflush flow factor - changed from 1.25 to 0 since membrane relaxation instead of
backflushing with permeate is typically sufficient for municipal strength wastewater
(Graham Best, GE Power and Water Regional Sales Manager, personal
communication, February 27, 2015).
Table 3-5. Life Cycle Inventory Operational Data for Scouring (AeMBR)
Water Output
Elcctricitv
NaOCl
(MGD)
(kWh/vr.)
(kg/yr.)
0.05 MGD
0.05
6730
49.3
0.1 MGD
0.10
13500
95.8
1 MGD
0.98
135,000
942
5 MGD
4.88
598,000
4,191
10 MGD
9.77
1,200,000
8,363
Table 3-6. Life Cycle Inventory Operational Data for Permeate Pumping (AeMBR)
Water Output
(MGD)
Electricity
(kWh/vr.)
0.05 MGD
0.049
1,570
0.1 MGD
0.10
3,140
1 MGD
0.98
31,200
5 MGD
4.88
156,000
10 MGD
9.77
311,000
Table 3-7. Life Cycle Inventory Operational Data for Waste Sludge Pumping (AeMBR)
Electricity
(kWh/vr.)
Sludge Output
(MGD)
0.05 MGD
39.6
0.0012
0.1 MGD
79.0
0.0023
1 MGD
786
0.023
5 MGD
3,910
0.12
10 MGD
7,810
0.23
The quantity of sodium hypochlorite needed for cleaning the membranes was calculated
separately from the CAPDETWorks model because the CAPDETWorks model assumes cleaning
with both sodium hypochlorite and citric acid, and not enough information is provided to
determine the quantity of each as calculated by CAPDETWorks. According to GE, cleaning with
citric acid is not necessary since nutrient removal using a coagulant is not included in this
analysis of MBR systems (Graham Best, GE Power, and Water Regional Sales Manager,
personal communication, February 27, 2015). Sodium hypochlorite consumption is estimated to
be 900 L of a 12.5% solution per year per 370 square feet of membrane surface area (GE Power
& Water, 2014). The cost of sodium hypochlorite was calculated using the unit cost of $2/kg
NaOCl derived from the cost of 14% by weight hypochlorite solution ($10/cu ft. 14% NaOCl)
provided in CAPDETWorks.
3-5
-------
3.0—Methodology
CAPDETWorks models sludge wasted from the AeMBR tank using a mixed liquor
suspended solids concentration of 12 g/L. The quantity of wasted sludge per day is shown in
Table 3-7.
3.2.1.1 Infrastructure
LCI infrastructure data for each sub process of the PFAS unit process were developed
using CAPDETWorks modeling software and are displayed in Table 3-8 and Table 3-9.
Table 3-8. Life Cycle Inventory Infrastructure Data for Aeration (AeMBR)
Earthworks (cu ft.)"
Concrete (cu ft.)
0.05 MGD
13,500
5,610
0.1 MGD
13,500
5,610
1 MGD
18,900
7,590
5 MGD
54,100
50,200
10 MGD
83,800
63,600
a Earthworks models energy requirements for removal of soil
associated with construction activities.
Table 3-9. Life Cycle Inventory Infrastructure Data for Sludge Recycle Pumping (AeMBR)
Earthworks (cu ft.)
0.05 MGD
1,650
0.1 MGD
1,690
1 MGD
2,550
5 MGD
6,330
10 MGD
11,100
LCI infrastructure data for each sub process of the MBR unit process are shown in Table
3-11 through Table 3-13. The hollow fiber membrane is made of polyvinylidene fluoride
(PVDF) (Cote et al., 2012). The quantity of PVDF used in the membrane was calculated based
on CAPDETWorks results for the total surface area of membrane required for each size system
and manufacturer specifications for the inner and outer diameter of a hollow fiber (GE Power &
Water, 2013). An Ecoinvent dataset for polyvinyl fluoride was used as a proxy to model PVDF.
Manufacture of MBR cassettes was not included in the model as data were not available, and
infrastructure typically is a small impact in LCAs when amortized over the equipment lifetime
and compared to daily operational requirements. Membrane lifetime was estimated to be 10
years (Cote et al., 2012). Because initial CAPDETWorks model calculations resulted in larger
MBR tanks than required by the GE ZeeWeed 500D LEAPmbr systems, total membrane surface
area was used to derive the number of cassettes needed per train from which the tank sizes were
calculated. Tank sizes, presented in Table 3-10 were modeled based on a GE factsheet (GE
Power & Water, 2014). A separate CAPDETWorks modeling run was carried out with the tank
length, width, and height specified in the input parameters to determine the amount of earthwork
and concrete required and construction costs associated with the tank infrastructure. An
Ecoinvent dataset for excavation using a hydraulic digger was used to model earthworks. The
hydraulic digger consumes 0.131 kg of diesel per cubic meter of earth moved.
3-6
-------
3.0—Methodology
Table 3-10. Aerobic Membrane Bioreactor Tank Dimensions
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
Membrane Surface
Area (m2)
591
1,180
11,800
52,600
105,000
Number of Trains
(Including Standby)
2
2
3
4
4
Number of Cassettes
per Train
1
2
3
8
16
Number of Modules
per Cassette
16
16
48
48
48
Length of Tanks (m)
1.52
2.44
6.60
16.8
33.0
Width of Tanks (m)
2.74
2.74
2.74
2.74
2.74
Height of Tanks (m)
3.66
3.66
3.66
3.66
3.66
Table 3-11. Life Cycle Inventory Infrastructure Data for Scouring (AeMBR)
Earthwork (cu ft.)
Concrete (cu ft.)
Membrane PVDF
(kjj/10 yrs.)
0.05 MGD
6,700
2,290
409
0.1 MGD
7,460
2,710
816
1 MGD
13,700
6,160
8,162
5 MGD
29,100
28,200
36,383
10 MGD
49,400
41,900
72,628
Table 3-12. Life Cycle Inventory Infrastructure Data for Permeate Pumping (AeMBR)
Earthwork (cu ft.)
0.05 MGD
1,600
0.1 MGD
1,610
1 MGD
1,680
5 MGD
1,880
10 MGD
2,170
Table 3-13. Life Cycle Inventory Infrastructure Data for Waste Sludge Pumping (AeMBR)
Earthwork (cu ft.)
0.05 MGD
1,600
0.1 MGD
1,600
1 MGD
1,600
5 MGD
1,620
10 MGD
1,640
3.2.2 Anaerobic MBR
While AeMBRs are largely commercialized at the scales investigated, the data behind the
AnMBR model is based on bench-scale and pilot scale systems. The energy balance calculations
for the AnMBR were conducted based on the work by Feickert et al. (2012). While this study
modeled a system treating 130 m3 of wastewater per day, the model was able to be parametrized
to theoretically increase the scale to 10 MGD. The following AnMBR sub processes are
3-7
-------
3.0—Methodology
incorporated, as displayed by Figure 3-2:
• Heating of influent for the bioreactor, using heat supplied by a heat exchanger
extracting heat from the resulting effluent and natural gas if additional heat is
necessary. For the sensitivity analysis, captured waste heat from electricity generation
displaces natural gas if the scenario includes CHP operations;
• Heat loss control for the anaerobic reactor and MBR tanks, assuming insulation is
used if reactor temperature is greater than ambient temperature;4
• Generation of methane from AnMBR headspace and utilization of that methane for
production of electricity (capture of waste heat is not modeled for the baseline
scenario but is included in selected scenarios in the sensitivity analysis);
• Effluent vacuum pump requiring purchased electricity or electricity generated from
the recovered methane of anaerobic process;
• Biogas recirculation pump requiring purchased electricity or electricity generated
from the recovered methane of anaerobic process;
• Dissolved methane recovery from the permeate (incorporated only in a sensitivity
analysis);
• Heat exchanger which uses heat from the effluent to heat the influent; and
• Sludge discharged to the sewer, which leaves LCA system boundaries.
4 Data from CAPDETWorks is used to calculate the surface area of the anaerobic digester(s) (i.e., reactor) and
AnMBR tanks. For a more conservative estimate of heat loss, the same convective heat loss formula for vertical
surfaces without insulation was used for horizontal surfaces exposed to the air. However, no heat loss was assumed
from the bottom of tanks in contact with the ground.
3-8
-------
3.0—Methodology
AnMBR Sub Processes
Heat-
*Heat-
¦Methane-
. Sludge
Discharged
to Sewer
Biogas
Permeate
Effluent to
Chlorination
with Sodium
Hypochlorite
Influent
from Fine
Screening
Biogas
* Dissolved methane recovery and CHP are included
only in the sensitivity analysis
¦Heat Loss Control-
Natural Gas
AnMBR
Influent
Heating
Anaerobic
Reactor
Effluent
Vacuum
Pump
Purchased
Electricity
* Dissolved
Methane
Recovery
Heat
Exchanger
Biogas
Recirculation
Pump
Electrical
Microturbine
or*CHP Electricity"
Figure 3-2. AnMBR Sub Processes (Adapted from Feickert et al. 2012)
This study investigated the operation of AnMBR WWT at 35°C, representative of a
mesophilic AnMBR system, and at 20°C, representative of a psychrophilic AnMBR system. LCI
operational data for the AnMBR process at 35°C and 20°C are displayed in Table 3-14 and Table
3-15, respectively. These LCI results were developed based on the methodology described in
Sections 3.2.2.1 through 3.2.2.4. Negative net electricity values mean the system produces more
electricity than it consumes so there is a net electricity displacement credit. The cost of
purchased energy was calculated using the cost factors for electricity, $0.10/kWh, and natural
gas, $15.50/1000 cubic feet, provided by CAPDETWorks. No cost is assigned to the energy in
the form of biogas or electricity generated on-site; however, a credit is received based on the
market cost of purchased electricity when the AnMBR system is a net electricity producer.
Table 3-14. Life Cycle Inventory Operational Data for AnMBR at 35°C
Water Output
Net Electricity
Net Natural Gas
NaOCl
Sludge Output
(MGD)
(kWh/yr.)
(m3/yr.)
(kg/yr.)
(MGD)
0.05 MGD
0.049
-20,871
25,504
170
0.0006
0.1 MGD
0.099
-41,952
35,022
339
0.001
1 MGD
0.99
-420,506
346,910
2,513
0.008
5 MGD
4.96
-2,102,970
1,731,625
10,471
0.04
10 MGD
9.92
-4,206,050
3,461,430
18,848
0.08
3-9
-------
3.0—Methodology
Table 3-15. Life Cycle Inventory Operational Data for AnMBR at 20°C
Water Output
Net Electricity
Net Natural Gas
NaOCl
Sludge Output
(MGD)
(kWh/vr.)
(m3/yr.)
(kg/yr.)
(MGD)
0.05 MGD
0.049
-18,263
0
170
0.0006
0.1 MGD
0.099
-36,737
0
339
0.001
1 MGD
0.99
-368,355
0
2,513
0.008
5 MGD
4.96
-1,842,212
0
10,471
0.04
10 MGD
9.92
-3,684,533
0
18,848
0.08
3.2.2.1 Biogas Production
Anaerobic treatment of the wastewater leads to formation of biogas. Typical biogas has a
methane content of 55% to 70% (this study uses a value of 65%) and most of the remaining
content is carbon dioxide (Metcalf and Eddy, 2014; Smith et al., 2012). Methane produced is
largely a function of the influent COD strength, with biogas production expressed commonly as
volume of CH4 per mass unit of COD. An overview of the methane production results for
AnMBR municipal water treatment scenarios in literature is shown in Table 3-16. This is
representative of biogas in the headspace of the reactor. Methane production increases with an
increase in the reactor temperature. For the purposes of this study, we have assumed an overall
methane production rate of 0.24 m3CH4/kg COD at 20°C and 0.27 m3CH4/kg COD at 35°C
(Martinez-Sosa et al., 2011). This range is within that reported by other sources in Table 3-16.
Table 3-16. AnMBR Parameters Influencing Methane Generation for Municipal
Wastewater
Influent
COD
Strength
(mg/L)
COD
Reactor
Reactor
Biogas
production
(m3 CH4/kg
COD)
Sou ree
Removal
(%)
Temperature
(°C)
HRT (day)
Volume
(m3)
Baeketal., 2010
-
64
-
0.5-2
0.01
-
Berube et al., 2006
-
70-90
11-32
-
-
-
Chang, 2014
342-600
90
20-30
1-25
0.06-0.35
0.25-0.35
Chu et al., 2005
383-849
-
-
6.04
-
-
Gao et al., 2010
500
-
-
2.08
-
-
Gimenez et al., 2011
445 ± 95
86.9 ±
3.4
33.3±0.2
0.25-0.875
1.3
0.294 ± 0.04
Ho & Sung et al., 2009
500
90
25
0.25-0.5
0.004
0.21-0.22
Ho & Sung et al., 2010
500
85->95
15-25
3.75-15
0.004
-
Hu & Stuckey, 2006
460±20
>90
35
2.0
0.003
0.22-0.33
Huang et al., 2011
550
>97
25-30
1.25-2.5
0.006
0.138-0.25
Kim et al., 2011
513
99
35
0.175-0.246
0.003
-
Lew et al., 2009
540
88
25
0.25
0.18
-
Lin et al., 2011
425
90
30
0.42
0.08
0.24
Martin et al., 2011
400-500
-
35
0.33-.58
-
0.29-0.33
Martinez-Sosa et al., 2011
402±73
84-94
20-35
1.5-0.67
0.35
0.24-0.27
Saddoud et al., 2007
685
88
37
0.625-2.5
-
-
Salazar-Pelaez et al., 2011
350
80
-
0.16-0.50
-
-
Smith et al., 2011
440
92
15
0.67
-
Smith et al., 2014
430
85-90
15-25
0.33
-
0.35
Wen et al., 1999
100-2600
97
12-25
0.16-0.25
-
-
Notes: COD = Chemical Oxygen Demand; HRT = Hydraulic Retention Time; SRT = Solids Retention Time
3-10
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3.0—Methodology
The recovered methane from the headspace is assumed to be converted to electricity for
operating the pumps in the treatment system. Biogas cleaning and compression is not included in
this model due to lack of available data. The destruction efficiency associated with burning the
biogas in an energy/thermal device (e.g., combined heat and power (CHP), biogas flare) is
modeled as 0.99 (IPCC, 2006), with one percent of the biogas produced escaping as fugitive
emissions rather than recovered for electricity. Conversion of methane to electricity is calculated
using Equation 1 and multiplying by the operation time (Feickert et al., 2012). The baseline
model assumes methane combustion energy not converted to electricity is lost as waste heat
through the exhaust stream.
EPch4= (PRcH4*LHVcH4)*DG_eff
(Eqn. 1)
Where:
EPCH4 =
PRCH4
LHVCH4 =
DG eff =
Electric power from recovered headspace methane in kW
Methane production rate (grams CH4/second)
Lower heating value methane (modeled as 50 kJ/g)
Overall efficiency power diesel engine for electric generator (modeled as
32 AO/.
While the baseline model assumes the recovered methane is used to produce only
electricity, sensitivity analyses in Section 5.0 include scenarios with biogas flaring and recovery
with CHP. With CHP, the additional waste heat is captured with a heat exchanger and used to
heat incoming water. Appendix E lists the parameters used to develop the inventory data for
biogas flaring and recovery of methane with CHP.
A portion of methane produced is dissolved in solution and leaves the system in the
permeate (Smith et al., 2012). While supersaturation of dissolved methane occurs in some types
of anaerobic reactors, this has not been found in AnMBR systems (Cookney et al., 2016). Thus,
the amount of methane per liter of permeate was calculated based on Henry's Law and the van't
Hoff-Arrhenius relationship along with coefficients for methane used to calculate Henry's
constant for methane.
Van't Hoff Arrhenius Relationship, solved for Henry's Constant (Metcalf and Eddy,
2014):
HCh4 = 10(~A/t+b) (Eqn. 2)
Where:
Hch4 = Henry's constant for methane at a given reactor temperature
A = 675.75
B = 6.880
T = reactor temperature in Kelvin
Henry's Law (adapted from Smith et al., 2014):
3-11
-------
3.0—Methodology
CH4 dissolved ~
(P™4/«™4) WO^hJ
(Eqn. 3)
Where:
CH4 , dissolved
Pch4
Hch4
concentration of dissolved methane in solution (g/liter)
0.65 atm, the partial pressure of methane in biogas
Henry's constant, as calculated for a given reactor temperature
55.5 mol/liter, the molarity of water
MWch4 = 16.04 g/mol, the molecular weight of methane
The concentration of methane dissolved in permeate varies based on the temperature of
the reactor. The same equations and coefficients were used to calculate the amount of methane
per liter of permeate that would remain in solution once the permeate was exposed to the
atmosphere, assuming normal temperature (20°C) and pressure (1 atm) in all scenarios and
1822.5 parts per billion methane in the atmosphere (Dlugokencky, 2015).
Based on previous literature, the baseline assumption for this study is a 0% recovery rate
of methane dissolved in permeate (Smith et al., 2014). Therefore, the amount of methane emitted
per liter of permeate is the difference between the total amount of dissolved methane and the
dissolved methane that remains in solution when discharged. Future advancements, however,
could lead to significant recovery of methane left in the permeate (Hu & Stuckey, 2006; Dagnew
et al., 2011; Gimenez et al., 2011; Kim et al., 2011; Smith et al., 2012; and Bandara et al., 2011).
Section 5 investigates sensitivity analysis results when including recovery of methane from the
permeate.
3.2.2.2 Recovery of Dissolved Methane in Permeate
The sensitivity analysis models several scenarios with recovery of dissolved methane in
the permeate for conversion to electricity. Membrane separation was selected as the methane
recovery method based on its simplicity of operation and maintenance, no hazardous chemical
use, and its good economic performance in low gas flow situations (Makaruk et al., 2010).
Equations calculating energy use for adiabatic compression have been found to provide a good
estimate for energy use for polytropic compression involved in membrane separation and were
used in this model to calculate electricity demand (Perry and Green, 1997).
kWRT
k-1
(Eqn. 4)
Where:
Wad
k
w
R
T
P out
Pin
power required for the compressor (Watts)
1.295, the heat capacity ratio
molar flow rate of methane (mol/s)
8.314 J/mol-K, the universal gas constant
inlet gas temperature (K), assumed same temperature as reactor
101.325 kPa, absolute discharge pressure
21.325 kPa, absolute inlet pressure
3-12
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3.0—Methodology
The sensitivity analysis model assumes an 80% recovery of methane dissolved in the
permeate (Makaruk et al., 2010). The capital cost of membrane separation technology was
determined using an engineering equation from Chemical Process Equipment (Walas, 1990)
based on the power requirement in kW for a screw-type compressor in 1985 and adjusted for
current cost using the Chemical Engineering Plant Cost Index (CEPCI) for 1985 and December
2014 (Bailey, 1986 and 2015).
Cost =
\CEPCU
(1830)(Power)0 71
(Eqn. 5)
Where:
Cost
CEPCI2014
CEPCI1985
Power
present cost in dollars of compressor for membrane separation
575.7, Chemical Engineering Plant Cost Index for Dec. 2014
325.3, Chemical Engineering Plant Cost Index for 1985
power requirement (kW) for compressor as found in Eqn. 4
3.2.2.3 Membrane Fouling and Sludge Output
Requirements for preventing membrane fouling, as indicated by previous work, were
assumed independent of wastewater strength (Smith et al., 2014). As for the AeMBR systems,
sodium hypochlorite consumption (see Table 3-14 and Table 3-15) is estimated using a factor of
900 L 12.5% NaOCl per year per 370 square feet of membrane surface area (GE Power & Water,
2014). Cost of sodium hypochlorite was calculated using the same method as for the AeMBR.
Membrane surface area required for each AnMBR system is listed in Table 3-22.
The amount of sludge returned to the main sewer system to be treated downstream at the
centralized WWTP was derived from the following equation from Metcalf and Eddy (2014) for
calculating solids retention time (SRT) for aerobic MBR systems and adapted for use with the
AnMBR systems. Solving for Q obtains the volume of sludge wasted per day. See Section
3.2.2.4 for a discussion of the solids concentration and Table 3-18 for tank volumes.
SRT= XaVa+XmVm (Eqn. 6)
Qwxm
Where:
Va = volume of anaerobic reactor (m3)
Vm = volume of membrane separation tank (m3)
Xa = solids concentration in the anaerobic reactor (mg/L)
Xm = solids concentration in the membrane separation tank (mg/L)
Qw = waste sludge flow rate (m3/day)
Sludge output is shown in Table 3-14 and Table 3-15 for the AnMBR systems operating
at 35°C and 20 °C, respectively. The remaining volume was assumed to be MBR permeate that
would then be pumped to the chlorination tanks for disinfection.
3-13
-------
3.0—Methodology
3.2.2.4 Infrastructure
LCI infrastructure data for the anaerobic reactor unit process were developed using
CAPDETWorks modeling software and are displayed in Table 3-17.
Table 3-17. Life Cycle Inventory Infrastructure Data for Anaerobic Reactor
Earthworks (cu ft.)
Concrete (cu ft.)
0.05 MGD
3,320
1,728
0.1 MGD
6,240
2,512
1 MGD
51,800
9,700
5 MGD
237,000
34,620
10 MGD
513,000
61,000
An AnMBR process engineer at GE stated that for AnMBR systems treating municipal
wastewater the HRT is typically around 8 hours, the SRT is between 40-80 days, and the mixed-
liquor suspended solids (MLSS) concentration is between 10 and 14 g/liter. This study uses an
SRT of 60 days and a MLSS of 12 g/L, the midpoints of the ranges provided by GE. The HRT,
SRT, and influent suspended solids concentrations were used to estimate the total tank volume
required for the anaerobic reactors. CAPDETWorks technical manual Section 2.19.6.3.3.1 was
used as guidance for the number of reactor tanks needed for each system based on the average
daily flow (Harris et al., eds. 1982). Typical tank configurations, including diameter and
sidewater depth, were based on figure 2.19-9 in the CAPDETWorks technical reference for
system sizes 1 MGD and greater and on CAPDETWorks equation 2.19.6.3.4.3 for 0.05 MGD
and 0.1 MGD systems (Harris et al., eds. 1982). The number of tanks, tank diameter, and tank
sidewall depth, as shown in Table 3-18, were used as input parameters to model anaerobic
reactor infrastructure quantities and cost using CAPDETWorks. The reactor tank is modeled
with a floating cover, which can adjust the volume of the tank to some degree.
Table 3-18. Anaerobic Reactor Tank Dimensions
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
Number of Tanks
1
1
1
2
2
Diameter (ft.)
15
20
50
70
95
Sidewall Depth (ft.)
18.2
19.1
24.4
28.0
32.4
Total Volume (cu ft.)
3,317
6,240
51,848
236,817
513,477
LCI infrastructure data for each sub process of the MBR unit process are shown in Table
3-19 through Table 3-21. Infrastructure data were taken from CAPDETWorks modeling results
unless otherwise noted.
Table 3-19. Life Cycle Inventory Infrastructure Data for MBR Tanks (AnMBR)
Earthwork (cu ft.)
Concrete (cu ft.)
Membrane PVDF
(kg/1.0 yrs.)
0.05 MGD
6,700
2,290
1,474
0.1 MGD
7,460
2,710
2,948
1 MGD
13,700
6,160
21,826
5 MGD
29,100
28,200
90,942
10 MGD
49,400
41,900
163,696
3-14
-------
3.0—Methodology
Table 3-20. Life Cycle Inventory Infrastructure Data for Permeate Pumping (AnMBR)
Earthwork (cu ft.)
0.05 MGD
1,600
0.1 MGD
1,610
1 MGD
1,680
5 MGD
1,880
10 MGD
2,170
Table 3-21. Life Cycle Inventory Infrastructure Data for Waste Sludge Pumping (AnMBR)
Earthwork (cu ft.)
0.05 MGD
1,600
0.1 MGD
1,600
1 MGD
1,600
5 MGD
1,620
10 MGD
1,640
Membrane surface area was determined by dividing the average daily flow by the
average net flux of 7.5 liters/m2/hour reported in a literature review by Chang (2014) for
AnMBR systems and confirmed through personal communication with a GE AnMBR product
manager (Nelson Fonseca, GE Power and Water Lead Product Manager for Anaerobic MBR,
August 18, 2015). Note that flux was assumed the same for both 35°C and 20°C operating
temperatures, so the potential increase in flux due to decreased viscosity of permeate at the
higher temperature was not taken into account. Table 3-22 displays membrane surface area
required for each AnMBR scale as well as MBR tank dimensions. Tank dimensions were derived
from membrane surface area requirements and GE guidelines for tank sizes as described in the
Aerobic MBR Infrastructure section of this report.
Table 3-22. Anaerobic Membrane Bioreactor Tank Dimensions
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
Membrane Surface
Area (m2)
1,051
2,103
21,029
105,146
210,293
Number of Trains
(Including Standby)
2
2
3
5
9
Number of Cassettes
per Train
2
2
7
16
16
Number of Modules
per Cassette
16
48
48
48
48
Length of Tanks (m)
2.43
4.57
14.7
33.0
33.0
Width of Tanks (m)
2.74
2.74
2.74
2.74
2.74
Height of Tanks (m)
3.66
3.66
3.66
3.66
3.66
Costs for infrastructure associated with the anaerobic MBR unit process were largely
derived from CAPDETWorks modeling results for the aerobic MBR unit process using tank
dimension input parameters as specified in Table 3-22 since CAPDETWorks software does not
3-15
-------
3.0—Methodology
include a unit process for AnMBR. Insulation costs for the AnMBR system operating at 35°C
were estimated using surface area calculations for the sides and top of the reactor and AnMBR
tanks based on anaerobic digester dimensions from CAPDETWorks. The insulation was assumed
to be 1-foot-thick and composed of equal volumes of expanded polystyrene (EPS) insulation
board and foil-faced fiberglass batts (Feickert et al., 2012). RSMeansOnline square foot
estimator provided cost factors of $1,59/sq. ft. of 12-inch-thick foil-faced fiberglass and $6.12/
sq. ft. of 12-inch-thick EPS ($1,53/sq. ft. for 3 inch EPS board multiplied by 4 for an equivalent
12-inch thickness) (The Gordian Group 2016). The capital cost for the microturbine units used to
generate electricity in the baseline scenarios was modeled using a factor of $l,660/kW of
electricity generated, the midpoint of a range found in three sources (Capehart, 2014) (NREL
FEMP, 2002) (Van Holde et al., 2002). For the sensitivity analysis in Chapter 5, capital cost for
the combined heat and power unit was calculated using a factor of $2,030/kW of electricity
generated, the midpoint of a range found in several reports (Capehart, 2014; Chambers and
Potter, 2002; NREL FEMP, 2002; U.S. EPA CHPP, 2011; Van Holde et al., 2002). The cost of a
flare, estimated by CAPDETWorks, is included in all AnMBR scenarios, as a flare is required as
a safety measure to burn excess methane.
3.3 Pre and Post Treatment Model
Life cycle environmental inventory and cost data for pre and post treatment modeling for
both the AnMBR and AeMBR were primarily derived from CAPDETWorks simulations as
illustrated in Figure 3-1. As discussed in Section 2.2, pre-treatment includes screening and grit
removal followed by fine screening. Post treatment includes disinfection with sodium
hypochlorite prior to the recycled water delivery to end users.
3.3.1 Preliminary Treatment (Screening and Grit Removal)
The screening and grit removal step is assumed equivalent for the AeMBR and AnMBR
model. CAPDETWorks default settings were used for input parameters to calculate the
infrastructure and energy requirements as well as grit landfilled after collection from a
mechanically cleaned bar screen and a horizontal grit removal unit. The CAPDETWorks model
assumes negligible water loss from screening and grit removal processes. The operational LCI
data for this work are displayed in Table 3-23.
Table 3-23. Life Cycle Inventory Operational Data for Preliminary Treatment
Water Output
Elcctricitv
Grit Disposed
(MGD)
(kWh/vr.)
(kg/yr.)
0.05 MGD
0.050
4,000
5.48
0.1 MGD
0.10
5,510
11.0
1 MGD
1.00
16,000
110
5 MGD
5.00
33,700
548
10 MGD
10.0
46,500
1,096
3-16
-------
3.0—Methodology
Table 3-24. Life Cycle Inventory Infrastructure Data for Preliminary Treatment
Earthworks (cu ft.)
Concrete (cu ft.)
0.05 MGD
1,655
547
0.1 MGD
1,748
595
1 MGD
2,515
947
5 MGD
4,256
1,586
10 MGD
5,847
2,061
Earthworks and concrete quantities required for construction of the grit channel were
derived from CAPDETWorks outputs of the length, width, and depth of the grit channel. The
calculation assumed these channel measurements describe the inner dimensions of the channel,
and used a conservative assumption that the two side walls and bottom wall were one-foot-thick
concrete. Required earth work was assumed to be 1 foot wider on either side of the two concrete
side walls and 1 foot below the concrete slab forming the bottom of the channel. The LCI
infrastructure data is shown in Table 3-24. Costs for preliminary treatment earthwork and
concrete were calculated using cost factors per unit of earthwork and concrete provided in
CAPDETWorks.
3.3.2 Fine Screening
The fine screening step is assumed equivalent for the AeMBR and AnMBR model. The
operational LCI data for this work are displayed in Table 3-25, and the infrastructure LCI data
are shown in Table 3-26.
Table 3-25. Life Cycle Inventory Operational Data for Fine Screening
Water Output
(MGD)
Electricity
(kWh/yr.)
0.05 MGD
0.050
100
0.1 MGD
0.10
200
1 MGD
1.00
2,070
5 MGD
5.00
10,360
10 MGD
10.0
20,720
Table 3-26. Life Cycle Inventory Infrastructure Data for Fine Screening
Earthworks (cu ft.)
0.05 MGD
32.6
0.1 MGD
65.2
1 MGD
652
5 MGD
3,260
10 MGD
6,521
Since CAPDETWorks does not include a fine screening module, manufacturer equipment
specifications were used to calculate electricity demand for operating fine screening equipment.
Huber Technology states energy consumption of screens, screening conveyors and wash-presses
ranges from 0.5 to 1.5 Wh per m3 of wastewater processed (Huber Technology, 2015). Since an
3-17
-------
3.0—Methodology
estimate of energy use for ancillary equipment was not readily available, the maximum of the
range provided by Huber Technology was used to calculate electricity consumption. As for
preliminary treatment, the fine screening process was assumed to result in negligible water loss.
Data on fine screening cost of construction and equipment installation as well as yearly
operation and maintenance costs were drawn from a Wastewater Technology Factsheet
published by the U.S. EPA Office of Water (U.S. EPA, 2003). The factsheet provided a cost
curve for horizontal shaft rotary screens for systems between 0.1 and 100 MGD. Linear
extrapolation was used to estimate these costs for the 0.05 MGD system. The cost of energy was
calculated using the electricity consumption for each system and an average U.S. cost of
electricity of 10 cents per kWh (as assumed by CAPDETWorks).
Earthworks required for installation of the fine screening equipment was based on
excavation dimensions for fine screening facilities associated with an MBR WWTP under
construction in Riverside, California (City of Riverside, 2013). The reported earthworks for the
Riverside fine screening facility was normalized to a volume of earthworks per million gallons of
wastewater treated and then extrapolated based on the daily flow for each WWTP scale
considered (City of Riverside, 2012). The cost of earthworks for fine screening was calculated
using the cost factor per unit of earthwork provided in CAPDETWorks.
3.3.3 Chlorination
The LCI data for the chlorination stage is assumed equivalent for the AeMBR and
AnMBR model. The operational LCI data for this work are presented in Table 3-27 and LCI data
for infrastructure are shown in Table 3-28. Cost data for the chlorination unit process were taken
directly from CAPDETWorks results except as noted below. Water output from chlorination is
higher for AnMBR than AeMBR because the AnMBR system operates with a longer SRT and
therefore treats more water per unit of sludge sent back into the main sewer line (Table 3-6 vs
Table 3-14 and Table 3-15). Water output volume from chlorination is assumed to be the same as
input volume.
Table 3-27. Life Cycle Inventory Operational Data for Chlorination
Water Output -
AcMBR/AnMBR
(MGD)
Electricity
(kWh/vr.)
NaOCl
(kg/yr.)
0.05 MGD
0.049/0.049
45,713
283
0.1 MGD
0.10/0.10
52,478
567
1 MGD
0.98/0.99
83,000
5,667
5 MGD
4.88/4.96
114,352
28,334
10 MGD
9.77/9.92
131,000
56,668
3-18
-------
3.0—Methodology
Table 3-28. Life Cycle Inventory Infrastructure Data for Chlorination
Earthworks (cu ft.)
Concrete (cu ft.)
0.05 MGD
58
1,824
0.1 MGD
116
1,847
1 MGD
1,160
2,383
5 MGD
5,810
4,720
10 MGD
11,600
7,640
In order to reuse the treated water, water quality standards must be met. The regulations
for water reuse are set by each state. However, U.S. EPA developed a set of guidelines for a
range of water reuse categories, which are used in this study (U.S. EPA, 2012). The water quality
standards are shown in Table 3-29.
Table 3-29. U.S. EPA Guidelines for Water Quality Standards for Unrestricted and
Restricted Urban Reuse
Urban Reuse -
Unrestricted
Urban Reuse-
Restricted
Units
BOD
<10
<30
mg/1
Total Suspended Solids
<30
mg TSS/1
Turbidity
<2
NTU
Fecal coliform
ND
<200
#/100 ml
pH
6.0-9.0
6.0-9.0
Chlorine Residual
>1
>1
mg/1
In general, aerobic MBR systems are expected to produce effluents with E. coli levels at
or below 100 count per 100 mL (Metcalf and Eddy, 2014), and a survey of 38 small water
recycling facilities found that 90% had turbidity levels less than 0.7 Nephelometric Turbidity
Units (NTU) (Hirani et al., 2013). CAPDETWorks modeling results showed AeMBR effluent
BOD concentrations less than 5 mg/L. Recent research reported that, under normal operating
conditions of an AeMBR system, a free chlorine contact time of 10 mg-min/L was sufficient to
achieve 5-log removal of a virus and reduce total coliform count to below detection levels of 2
colony forming units (CFU) per 100ml (Hirani et al., 2014). EPA guidelines for water reuse
recommend a 30-minute contact time during chlorination and a 1 mg/L chlorine residual at a
minimum (U.S. EPA, 2012). Therefore, an influent coliform count of 100/100 mL, a 2 mg/liter
chlorine dosage, and the default 30-minute contact time were chosen as input parameters to the
CAPDETWorks chlorination model for AeMBR. The input parameters are conservative in
comparison with the 10 mg-min/L shown to be sufficient disinfection for AeMBR effluent to
meet the restricted and unrestricted urban U.S. EPA water reuse guidelines, but allow for some
variability in effluent quality and ensures there would still be at least 1 mg/1 of chlorine residual.
Given that a study of a bench-scale AnMBR system with 60 day SRT found that AnMBR
effluent had no detectable fecal coliform and total suspended solids concentration less than 1
mg/L, the same contact time and dosage level was modeled for the AnMBR as well (Herrera-
Robledo et al., 2010).
Since CAPDETWorks only models chlorination with chlorine gas, a stoichiometric
3-19
-------
3.0—Methodology
conversion was made to calculate sodium hypochlorite consumption required from the
CAPDETWorks output of average chlorine required per day. All infrastructure data were taken
from the CAPDETWorks modeling results. The cost of sodium hypochlorite was calculated
using the unit cost of $2/kg NaOCl derived from the cost of 14% by weight hypochlorite solution
($10/cu ft. 14% NaOCl) provided in CAPDETWorks. CAPDETWorks assumes that all
chlorination systems with average influent flows of 5 MGD or less use 118,000 kWh of
electricity per year. This assumption did not seem reasonable for the WWT systems as small as
0.05 MGD. CAPDETWorks technical manual provides equation number 2.13.6.12.2 to calculate
the annual electrical demand for chlorination units for systems larger than 5 MGD (Harris et al.,
eds. 1982). This equation was used to manually calculate electricity demand for chlorination for
the 0.05, 0.1, 1, and 5 MGD systems (see Table 3-27).
kWh = (83,000) (Qavg)01991 (Eqn. 7)
Where:
Qavg = average daily flow in MGD
kWh = annual electricity consumption to operate the chlorinator and evaporator
The cost of energy was calculated using the average cost of electricity per kWh provided
by CAPDETWorks.
3.4 Wastewater Collection System Model
This section covers the wastewater collection system operational and infrastructure
requirements for the different population density scenarios investigated. It is assumed the
wastewater collection system infrastructure has been in place prior to establishment of the plug-
in MBR systems. Infrastructure requirements are included in the scope of the LCA model, since
these impacts are amortized over the lifetime of the pipe system. However, infrastructure for the
collection system is not included in the cost analysis since all costs were incurred prior to
establishment of the decentralized MBR systems.
3.4.1 Infrastructure Calculations
The collection system pipe composition and pipe lifetime are displayed in Table 3-30 and
Table 3-31 respectively.
3-20
-------
3.0—Methodology
Table 3-30. Collection System Pipe Material by Diameter
% of Collection System
Diameter of Pipe
(inches)
PVC
Vitrified
Clay
Concrete
Reinforced
Concrete
Cement-
Lined
Ductile
Iron
8
7.1%
31.8%
33.1%
7.0%
1.1%
10 to 12
0.9%
4.0%
4.1%
0.9%
0.1%
15 to 21
0.4%
2.0%
2.1%
0.4%
0.1%
24 and larger
0.4%
2.0%
2.1%
0.4%
0.1%
Source:
Rowlett T. 2015. Personal communication with T. Rowlett, Water Infrastructure Expert at PG
Environmental, LLC, 4 March 2015.
Table 3-31. Collection System Pipe Lifetimes by Material Type
Pipe Material
PVC
Vitrified
Clav
Concrete
Reinforced
Concrete
Cement-
Lined
Ductile Iron
Lifetime (Years)
55
100
105
105
97.5
Source:
American Water Works Association. 2012. Buried No Longer: Confronting America's Water
Infrastructure Challenge
The total length of pipe calculated per scenario is illustrated in Figure 3-3 and Figure 3-4
(Rowlett, 2015).
800000
700000
600000
g 500000
E
"S 400000
u
2 300000
m
S
200000
100000
0
Figure 3-3. Total Meters of Sewer Pipe by Scenario on the Basis of People Served
10,000
50,000
100,000
People Served
People per square mile
100,000
People per square mile
50,000
People per square mile
10,000
People per square mile 2,000
3-21
-------
3.0—Methodology
800000
700000
600000
500000
m
a.
0.
400000
o
¦w
re
a»
a>
¦w
re
6.0E-04
5.0E-04
& 4.0E-04
ro
3.0E-04
'a.
•—
I 2.0E-04
m
i/i
n-
o
E 1.0E-04
m
0.0E+00
500
1,000
10,000
50,000
100,000
People Served
People per square mile
100,000
People per square mile
50,000
People per square mile
10,000
People per square mile
2,000
Figure 3-5. Meters of Sewer Pipe by Scenario Normalized to Cubic Meters of Water
Treated and on the Basis of People Served
3-22
-------
3.0—Methodology
¦a
a>
¦w
re
a>
a>
¦w
re
6.0E-04
5.0E-04
4.0E-04
y = 6E-05x2 - O.OOOlx + 9E-05
R2 = 0.9985
a>
a
'a.
U
a>
£
o
!/)
o
!/)
•—
OJ
OJ
3.0E-04
2.0E-04
1.0E-04
People Served 500
People Served 1,000
People Served 10,000
People Served 50,000
People Served 100,000
0.0E+00
100,000
50,000
10,000
2,000
People per square mile
Figure 3-6. Meters of Sewer Pipe by Scenario Normalized to Cubic Meters of Water
Treated and on the Basis of People per Square Mile
3.4.2 Operational Requirements
The operational requirements for delivery of the wastewater from the user to the
treatment facility is displayed in Table 3-32 and normalized to a cubic meter of wastewater
treated. Since the model considers a gravity collection system, the study makes the simplifying
assumption the volume of wastewater drives the overall energy requirements for operation.
Table 3-32. Collection System Operational Requirements per Cubic Meter of Wastewater
Treated
Input
Unit
Value
Wastewater treated
m3
1.0
Purchased electricity
kWh
0.0067
Natural gas
m3
0.00034
Diesel
1
0.0018
Gasoline
1
0.0015
Source: Cashman, S., A. Gaglione, J. Mosley, L. Weiss, N. Ashbolt, T.
Hawkins, J. Cashdollar, X. Xue, C, Ma, AND S. Arden. Environmental
and cost life cycle assessment of disinfection options for municipal
wastewater treatment. U.S. Enviromnental Protection Agency,
Washington, DC, EPA/600/R-14/377, 2014.
3.5
Recycled Water Delivery System
This section covers the recycled water delivery system operational and infrastructure
requirements for the different population density scenarios investigated. It is assumed the
recycled water delivery infrastructure is installed with establishment of the MBR systems. The
3-23
-------
3.0—Methodology
recycled water delivery model covers the displacement of potable water, as described in Section
3.5.3.
3.5.1 Infrastructure Calculations
The pipe material and diameter composition modeled for recycled water delivery pipe are
displayed in Table 3-33, with associated pipe material lifetimes displayed in Table 3-34. Overall
impacts of pipe materials are amortized over their useful lifetimes.
Table 3-33. Recycled Water Delivery System Pipe Material by Diameter
% of Recycled Water Delivery System
Diameter of
Pipe (inches)
PVC
Ductile Iron
Steel
Concrete
6
36.0%
44.0%
0.0%
0.0%
8
4.5%
5.5%
0.0%
0.0%
10 to 12
0.0%
3.0%
0.8%
1.3%
14-inch and
larger
0.0%
3.0%
0.8%
1.3%
Source:
[1] American Water Works Association. 2012. Buried No Longer: Confronting
America's Water Infrastructure Challenge
[2] Rowlett, T. 2015. Personal communication with T. Rowlett, Water Infrastructure
Expert at PG Environmental, LLC, 4 March 2015.
Table 3-34. Recycled Water Delivery System Pipe Lifetimes by Material Type
Pipe Material
PVC
Ductile Iron
Steel
Concrete
Lifetime (Years)
55
110
80
105
Source:
American Water Works Association. 2012. Buried No Longer: Confronting
America's Water Infrastructure Challenge
The pipe length for the recycled water delivery system is similar to that of the collection
system, as this study assumes all recycled water is delivered back to the original user. Some
additional piping is, however, required for the recycled water to loop the distribution system. The
total pipe modeled for the recycled water delivery system is provided in Table 3-35.
Table 3-35. Total Meters of Recycled Water Delivery Pipe per Scenario
People Served
500
1,000
10,000
50,000
100,000
People per
square mile
100,000
240
480
4,801
24,003
48,006
50,000
514
1,029
10,287
51,435
102,870
10,000
1,886
3,772
37,719
188,595
377,189
2,000
3,858
7,715
77,152
N/A
N/A
3-24
-------
3.0—Methodology
3.5.2 Operational Requirements
For distribution of the recycled water from the decentralized wastewater treatment
facility back to the end user, the pumping energy required for water delivery is affected by
changes in elevation throughout the pipe network as well as head losses due to friction inside the
pipe. Changes in elevation throughout the distribution network can vary greatly depending on the
geographic location being modeled and therefore are not included in the pumping energy
calculations in this analysis. Frictional head losses are influenced by the inside diameter of the
pipe, the flow rate through the pipe, and the smoothness of the interior pipe wall (DIPRA, 2006).
The Hazen-Williams coefficient is an indicator of the smoothness of the pipe interior. The higher
the coefficient, the smoother the surface and the lower the frictional head loss. The Hazen-
Williams coefficient values used in the analysis are shown in Table 3-36.
Table 3-36. Hazen-Williams Coefficients by Pipe Material
Pipe Material
Hazen-Williams
Coefficients
PVC
150
Ductile Iron
140
Steel
140
Concrete
140
Source: Ductile Iron Pipe Research
Association (DIPRA). Hydraulic Analysis
of Ductile Iron Pipe. Table 2.
Frictional losses and associated pumping energy increase with increasing distance that
water travels through the pipe. Pumping distance per customer served decreases with increasing
population density. The previously displayed Table 3-35 shows the length of water distribution
pipe modeled for the population scenarios evaluated. The mix of pipe sizes and types used for
recycled water distribution was previously presented in Table 3-33.
Pumping energy to overcome frictional head losses was calculated for each pipe type and
diameter for a representative flow velocity of 2 feet/second (Uni-Bell PVC Pipe Association,
2015) using the following equations:
Volumetric flow rate "q" in gal/min per foot of pipe: tt (dh/2)21/(231 in3/gal)*v*60 sec/min (Eqn. 8)
Where
dh
1
v
Head loss
Where
c
q
dh
3-25
= hydraulic diameter in inches (inside diameter of pipe)
= length of pipe in inches (12 inches when calculating gal/min/foot of pipe)
= flow velocity in feet/sec
H" (in feet/100 feet of pipe): 0.2083 (100/c)L852 qL852/ dh4'8655 (Eqn. 9)
= Hazen-Williams coefficient
= flow rate in gal/min (from equation above)
= hydraulic diameter in inches
-------
3.0—Methodology
Pumping energy (kwh/yr.) = 1.65*H*q/E*l (Eqn. 10)
Where
c
Hazen-Williams coefficient
H
head loss (from previous equation, in feet/100 feet of pipe)
q
flow rate in gal/min (from first equation)
E
pump efficiency (80% used in this study)
1
hundred feet of pipe evaluated (dependent on customers served and
population density; see table above)
A weighted average pumping energy was then compiled based on the values for the
individual pipe sizes and types and their percentage of the distribution system shown in the table
above. This pumping energy is presented in kWh per year for each scale and population density
scenario in Table 3-37.
Table 3-37. Recycled Water Delivery Electricity Consumption per Scenario
kWh/vr.
MGD
0.05
0.1
1
5
10
LOO.000 #ppl/sqmi
983
1,226
5,586
24,963
49,186
50.000 #ppl/sqmi
1,260
1,780
11,122
52,646
104,551
lO.OOO #ppl/sqmi
2,644
4,548
38,805
191,058
381,376
2.000 #ppl/sqmi
4,634
8,527
78,599
sqm = square mile; ppl = people; MGD = million gallons per day
3.5.3 Displacement of Drinking Water
The use of recycled water is assumed to replace the equivalent quantity of drinking water
produced in Cincinnati (Cashman et al., 2014a). Based on the recycled water produced under the
AeMBR and AnMBR decentralized treatment described in Table 3-6, Table 3-13, and Table
3-14 and an assumption of 19% water loss during recycled water distribution (Cashman et al.,
2014a), the volume of potable water displaced can be calculated using the following equation.
Volume of displaced potable water = volume of water treated - volume of water treated * % (Eqn. 11)
water lost to sludge-volume of water treated*(l-% water lost to sludge) * % water loss during
distribution
Table 3-38 displays the recycled water produced and delivered by each scenario scale per
year. In the LCA model, it is assumed that each cubic meter of recycled water delivered to the
user displaces one cubic meter of potable water.
3-26
-------
3.0—Methodology
Table 3-38. Recycled Water Delivered per Year and
Associated Parameters by Scenario Scale
AcMlili - per rcur
\\ silcr
I resiled
(ni3)
Pcrmcsilc
produced
(m3)
Kcoclcd
\\ silcr
dcli\crcd
(iii3)
\\ silcr
loss lo
sludge
\\ silcr loss
duiiuii
distribution
0.05 mcd
69,130
67,526
54,696
2.32%
19%
0.1 MCI)
138,259
135,051
109,392
2.32%
19%
1 M(.l)
1,382,591
1,350,515
1,093,917
2.32%
19%
5 MCI)
6,912,954
6,752,573
5,469,584
2.32%
19%
10 MCI)
I \s:5.^ir
1 v5(i5.14(.
lll.'JVJ. |(iS
: ^"h
IT.,
¦I iiMlili - per year
\\ silcr
1 resiled
(in3)
Pcrmcsilc
produced
(in3)
Kcoclcd
\\ silcr
dcli\crcd
(iii3)
\\ silcr
loss 1(1
sludue
\\ silcr loss
during
distribution
0.05 mcd
69,130
68,252
55,284
1.27%
19%
0.1 MCI)
138,259
136,622
110,664
1.18%
19%
1 MCI)
1,382,591
1,370,977
1,110,491
0.84%
19%
5 MCI)
6,912,954
6,861,798
5,558,056
0.74%
19%
10 MCI)
13,825,907
13,719,448
11,112,753
0.77%
19%
The system boundaries for the production of drinking water are displayed in Figure 3-7.
The overall impacts from drinking water production, which are displaced in this study, are
provided in Table 3-39 (Cashman et al., 2014a). The baseline water treatment system is based on
the GCWW Richard Miller Treatment Plant. The data in the GCWW model is representative of
the year 2011, in which 106 MGD of potable water were produced. The population density for
this drinking water is representative, therefore, of the greater Cincinnati region. The system
boundaries for drinking water include water losses during distribution to the consumer. A
sensitivity analysis is included in Section 5.3 assessing the relative change in global warming
potential using other reported literature values for electricity consumption during drinking water
treatment and distribution.
3-27
-------
3.0—Methodology
Aluminur
Prodi
n Sulfate
ction
Source Water
Acquisition
Alum Coagulant
and Coagulant Aid
Production
lu
Flocculation
Lime Production
Sand Production
Sedimentation
Filtration
Bituminous Coal
Production
Granular Activated
Carbon Production
Granular Activated
Carbon —
Regeneration
Adsorption
Sodium Hydroxide
Production
Conditioning <¦
Gaseous Chlorine
Production
L
Primary
Disinfection,
Gaseous Chlorine
Hydrofluorosilicic
Acid Production
Fluoridation
Sodium
Hypochlorite
Production
L
Transport, Treated
Drinking Water, Water
Supply Pipeline
-~ Distribution
->¦
CDrinking Water
Consumption
Iron Sulfate
Production
Disposal of
Sedimentation
Waste
Sodium
Hexametaphosphate
Production
©
L>
Primary Input/
Final Demand
Primary Process
Reference
Supply Chain
Or gate (multiple
outputs)
Or gate (multiple
inputs)
Figure 3-7. System Boundaries of Drinking Water Treatment
Drinking water treatment operations along with infrastructure raw
material extraction and construction are within the system boundaries.
End-of-life of infrastructure is excluded due to lack of available data.
3-28
-------
3.0—Methodology
Table 3-39. Displaced Drinking Water Treatment Impacts
Results Category
Unit
Impaet/m3 Drinking Water Delivered
Global Warming
kg C02 eq
1.08
Energy Demand
MJ
20.3
Fossil Depletion
kg oil eq
0.37
Acidification
kg H+ mole eq
0.48
Eutrophication
kg N eq
9.7E-04
Blue Water Use
m3
1.20
Smog
kg 03 eq
0.068
Ozone Depletion
kg CFC-11 eq
2.8E-08
Human Health, Cancer, Total
CTU
2.9E-11
Human Health, NonCancer, Total
CTU
3.2E-11
Human Health, Criteria
kg PM10 eq
0.0015
Ecotoxicity, Total
CTU
4.5E-04
3.6 Data Quality
In accordance with the project's Quality Assurance Project Plan (QAPP) entitled Quality
Assurance Project Plan for Life Cycle and Cost Assessments of Water and Wastewater
Treatment Options for Sustainability: Influence of Scale on Membrane Bioreactor Systems
approved by EPA on April 21, 2016 (ERG, 2016), ERG collected existing data5 to develop the
LCA and cost estimates for the AeMBR and AnMBR systems investigated in this study. As
discussed in Section 3.1 through Section 3.5, the life cycle inventory and cost estimate data
sources include CAPDETWorks Version 3.0 (Hydromantis, 2014), EPA reports, peer-reviewed
literature, publicly available equipment specifications from communication with technology
vendors, and industry-accepted construction cost data and indices. ERG evaluated the collected
information for completeness, accuracy, and reasonableness. In addition, ERG considered
publication date, accuracy/reliability, and costs completeness when reviewing data quality.
Finally, ERG performed conceptual, developmental, and final product internal technical reviews
of the LCA and costing methodology and calculations for this study.
Table 3-40 presents the data quality criteria ERG used when evaluating collected cost
data. ERG documented the data quality for each data source for each criterion in a spreadsheet
for EPA's use in determining whether the cost data are acceptable for use. All of the references
used to develop the costs met all of the data quality criteria with the exception of infrastructure
and labor costs for the AnMBR unit process which is estimated using CAPDETWorks data for
conventional anaerobic digestion. Since AnMBR is currently only operating at pilot-scales,
costing data on construction and labor for operating and maintaining AnMBR reactors at full-
scale plants are not yet available.
5 Existing data means information and measurements that were originally produced for one purpose that are
recompiled or reassessed for a different purpose. Existing data are also called secondary data. Sources of existing
data may include published reports, journal articles, LCI and government databases, and industry publications.
3-29
-------
3.0—Methodology
Table 3-40. Cost Data Quality Criteria
Quality Criterion:
Cost Data
Description/Definition
Acceptance Specifications
Current
Report the time period of the data.
Costs are converted to a standard year using
RSMeans Construction Index or other
standard cost index.
Complete
Ensure all aspects of the technology costs are
reported.
Cost estimates are completed using all input
costs for energy, labor, chemicals, and waste
disposal.
Representative
Report if the costs used are representative of
the technology studied.
Costs are based on data from peer reviewed
literature, vendor information and
engineering software specific to the
technologies studied.
Accurate/Reliable
Document the sources of the data. Confirm
calculations are based on sound methodology
and technically correct.
Data sources and calculations were
documented and reviewed.
Table 3-41 presents the data quality criteria ERG used when evaluating collected life
cycle inventory data. ERG documented qualitative descriptions of the source reliability,
completeness, temporal correlation, geographical correlation, and technological correlation in a
spreadsheet for EPA's use in determining whether the life cycle inventory data are acceptable for
use. Table 3-41 also lists the approximate overall data quality score achieved for the AeMBR and
AnMBR LCI model. Because the life cycle inventory model uses data from existing peer
reviewed literature, information from technology vendors, and engineering design software to
approximate average conditions in the U.S., a data quality score higher than 3 is difficult achieve
for all criteria with the exception of technological correlation. However, in all cases, the best
available existing data identified during the comprehensive literature review were used. For
technological correlation, only data from the technology (e.g., GE ZeeWeed® 500D hollow fiber
membranes using LEAPmbr Aeration Technology for MBR step), process, or material being
studied were considered.
3-30
-------
3.0—Methodology
Table 3-41. Life Cycle Inventory Data Quality Criteria
Imlicalor
Reporting Criteria
Score
AeMliK
(hcrall
Result
An M lilt
Oierall
Kesull
Source
Reliability
Data \ allied based on measurement.
1
Dala \ allied
with many
assumptions, or
non-verified
but from
quality source
(score - 3).
Dala \ allied
with many
assumptions, or
non-verified but
from quality
source (score =
3).
Data verified based on some assumptions
and/or standard science and engineering
calculations.
2
Data verified with many assumptions, or non-
verified but from quality source.
3
Qualified estimate.
4
Non-qualified estimate.
5
Completeness
Representative data from a sufficient sample of
sites over an adequate period of time.
1
Representative
ness unknown
or incomplete
data sets (score
= 5).
Representativen
ess unknown or
incomplete data
sets (score = 5).
Smaller number of sites, but an adequate period
of time.
2
Sufficient number of sites, but a less adequate
period of time.
3
Smaller number of sites and shorter periods or
incomplete data from an adequate number of
sites or periods.
4
Representativeness unknown or incomplete data
sets.
5
Temporal
Correlation
Less than 3 years of difference to year of
study/current year.
1
Less than 10
years of
difference
(score = 3).
Less than 10
years of
difference
(score = 3).
Less than 6 years of difference.
2
Less than 10 years of difference.
3
Less than 15 years of difference.
4
Age of data unknown or more than 15 years of
difference.
5
Geographical
Correlation
Data from area under study.
1
Data from area
with similar
production
conditions
(score = 3).
Data from area
with similar
production
conditions
(score = 3).
Average data from larger area or specific data
from a close area.
2
Data from area with similar production
conditions.
3
Data from area with slightly similar production
conditions.
4
Data from unknown area or area with very
different production conditions.
5
Technological
Correlation
Data from technology, process, or materials
being studied.
1
Data from
technology,
process, or
materials being
studied (score
= 1).
Data from
technology,
process, or
materials being
studied (score =
1).
Data from a different technology using the same
process and/or materials.
2
3
Data on related process or material using the
same technology.
4
Data or related process or material using a
different technology.
5
* Approximate score based on average of LCI unit process scores.
3-31
-------
3.0—Methodology
ERG developed the CAPDETWorks input files containing all the necessary information
and data required for the tool to execute the AeMBR designs and engineering costing. All
CAPDETWorks input files were reviewed by a team member knowledgeable of the project, but
who did not develop the input files. The reviewer ensured the accuracy of the data transcribed
into the input files, the technical soundness of methods and approaches used (i.e., included all of
the cost components and LCA inputs) and the accuracy of the calculations (i.e., used the
methodology in Section 3.1 through Section 3.5 to calculate the costs).
ERG developed the supplemental cost and life cycle inventory estimates for the AnMBR
and other unit process not covered in CAPDETWorks an Excel® Workbook. A team member
knowledgeable of the project, but who did not develop the Excel® workbook, reviewed the
workbook to ensure the accuracy of the data transcribed into the workbook, the technical
soundness of methods and approaches used, and the accuracy of calculations.
ERG input all life cycle inventory data developed into the openLCA software
(GreenDelta, 2015). A team member knowledgeable of the project, but who did not develop the
model, reviewed the openLCA model to ensure the accuracy of the data transcribed into the
software.
3-32
-------
4.0—Baseline Results
4.0 Baseline Results
The focus of the baseline results is energy demand, global warming potential, and costs.
However, the LCA model was constructed to cover a comprehensive suite of environmental
impact categories. The full LCIA results are provided in Appendix B of this report. Additional
findings on net water savings are provided in this Section.
4.1 Detailed AeMBR Energy Results
The cumulative energy demand results for all AeMBR scenarios are presented in Figure
4-1 on an annual basis. Similar results are illustrated in Figure 4-2, but on a basis of m3
wastewater treated. Energy demand impacts decrease comparatively as the population density
increases and the scale of the system increases. Net energy demand benefits are realized for 1
MGD systems and above. Detailed cumulative energy demand results for all AeMBR scenarios
on an annual basis are presented in Appendix A (Table A-l through Table A-5). These tables
show the relative breakout of impacts for infrastructure, energy for operation, and chemical
consumption. Infrastructure, including collection system and recycled water delivery piping,
contributes to 0.2% to 1.6% of the overall energy demand impacts for the AeMBR (excluding
the credit for displaced drinking water). The highest infrastructure burdens are seen in the semi-
rural single family land use type. Operational impacts are overwhelmingly higher than
infrastructure impacts with the largest energy demand required for aeration followed by
chlorination and scouring. Operational impacts are dominated by on-site electricity usage, which
accounts for approximately 90% of operational energy demand burdens of the AeMBR.
Production of chemicals for consumption contributes the remaining 10% to total operational
energy demand for the AeMBR. There are significant net energy benefits from recycled water
displacement of drinking water.
4-1
-------
4.0—Baseline Results
100.000.000
0.05
MGD
AeMBR
[semi
rural
single
family]
0.05 0.1 MGD 1 MGD
0.05 0.05 MGD AeMBR 0.1 MGD AeMBR
MGD MGD AeMBR [semi 0.1 MGD 0.1 MGD AeMBR [semi 1 MGD
AeMBR AeMBR [high rural AeMBR AeMBR [high rural AeMBR AeMBR
[single [multi density single [single [multi density single [single [multi
family] family] urban] family] family] family] urban] family] family] family]
1 MGD
1 MGD AeMBR 5 MGD
[high
density
urban]
5 MGD 10 MGD
5 MGD AeMBR 10 MGD 10 MGD AeMBR
AeMBR AeMBR [high AeMBR AeMBR [high
[single [multi density [single [multi density
family] family] urban] family] family] urban]
50.000.000
3 0
-50.000.000
573"879 548.146 5
530.063526.472 230.555 179.043 143,090 135.
,909
•7 onn co -7.633.332 \
-45.730.658
-47.514.952
-6.756.690 -7-200-452 -7.705.003
47.874.045
-100.000.000
-94.406.078
-97.9
-150.000.000
5,718 583
1 Wastewater collection ¦ Pre treatment BMBR operation (electrical demand, chemicals) ¦ MBR infrastructure ¦ Post treatment ¦ Recycled water delivery ¦ Displaced drinking water •Total
-200.000.000
Figure 4-1. AeMBR Cumulative Energy Demand Results (MJ/Year)
4-2
-------
4.0—Baseline Results
25
20
15
10
0.05 MGD 0.1 MGD 1 MGD
AeMBR 0.05 MGD AeMBR 0.1 MGD AeMBR
[semi 0.05 MGD0.05 MGD AeMBR [semi 0.1 MGD 0.1 MGD AeMBR [semi
rural AeMBR AeMBR [high rural AeMBR AeMBR [high rural
single [single [multi density single [single [multi density single
family] family] family] urban] family] family] family] urban] family]
1 MGD 5 MGD 10 MGD
1 MGD 1 MGD AeMBR 5 MGD 5 MGD AeMBR 10 MGD 10 MGD AeMBR
AeMBR AeMBR [high AeMBR AeMBR [high AeMBR AeMBR [high
[single [multi density [single [multi density [single [multi density
family] family] urban] family] family] urban] family] family] urban]
-10
mi
8.30
793 • 7.67 • 7.62
mi
¦ Wastewater collection
¦ Pre treatment
I MBR operation (electrical demand, chemicals)
15
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
• Total
Figure 4-2. AeMBR Cumulative Energy Demand Results (MJ/m3 Wastewater Treated)
4-3
-------
4.0—Baseline Results
4.2 Detailed AnMBR Energy Results
Based on preliminary model findings, it was determined that reactor temperature is a
significant parameter in the overall environmental impacts for the AnMBR system. Therefore, as
discussed in Section 3, results are modeled for a high [mesophilic (35°C)] and low [psychrophilic
(20°C)] temperature. Less methane is produced, and thus recovered, under lower temperature
scenario. However, less natural gas is required to keep the wastewater at a higher overall
temperature in the 20°C scenario. The next sections cover the energy demand results for each of
these temperature scenarios.
4.2.1 AnMBR Energy Results, 35°C Reactor Temperature
Figure 4-3 displays the AnMBR cumulative energy demand impacts on an annual basis
with the reactor operating at 35°C, while Figure 4-4 illustrates the same results per m3
wastewater treated basis. Detailed cumulative energy demand results for all AnMBR scenarios
operating at 35°C on an annual basis are presented in Appendix A (Table A-6 through Table A-
10).
For the AnMBR operating at 35°C, net benefits are not realized until the 5 MGD scale.
The driver for AnMBR operational impacts under this scenario is the heating of the influent by
natural gas, even when considering the heat recovery from the effluent. Because all water must
be heated from 20°C to 35°C regardless of the flow, no economies of scale are realized for this
step. That is, the heating of the influent is linear across scales. The relative savings from the
biogas recovery are overshadowed by the impact for heating the influent.
4-4
-------
4.0—Baseline Results
0.05 MGD 0.1 MGD 1 MGD
AiiMBR 0.05 MGD AiiMBR 0.1 MGD AiiMBR 1 MGD 5 MGD
[semi 0.05 MGD0.05 MGD AiiMBR [semi 0.1 MGD 0.1 MGD AiiMBR [semi 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD
rural AiiMBR AiiMBR [high rural AiiMBR AiiMBR [higli rural AiiMBR AiiMBR [higli AiiMBR AiiMBR [high AiiMBR
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family]
10 MGD
10 MGD AnMBR
AnMBR [high
[multi density
family] urban]
250.000.000
200.000.000
150.000.000
100.000.000
50.000.000
^ 0
-50.000.000
1.795.710
1.351.948
563.197
537.464 519.380 515.790 627.664 576.152 540.199 533 019
919.068 847_397
± ± ± I
12
-5.026.480
4.667.387
-7,739,946
-11.332.727
-12.052.451
• <> a
-100.000.000
-150.000.000
-200.000.000
-250.000.000
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
• Total
Figure 4-3. AnMBR, 35°C Reactor Temperature, Cumulative Energy Demand Results (MJ/Year)
4-5
-------
4.0—Baseline Results
30.00
25.00
20.00
15.00
•S 10.00
5.00
0.00
-5.00
-10.00
-15.00
0.05 MGD 0.1 MGD 1 MGD
AiiMBR 0.05 MGD AiiMBR 0.1 MGD AiiMBR 1 MGD 5 MGD 10 MGD
[semi 0.05 MGD0.05 MGD AiiMBR [semi 0.1 MGD 0.1 MGD AiiMBR [semi 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
rural AiiMBR AiiMBR [higli rural AiiMBR AiiMBR [high rural AiiMBR AiiMBR [higli AiiMBR AiiMBR [higli AiiMBR AiiMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
llllim
;-15 • 7.77
7.51 • 7.46
4 54 • 4.17 « 3.91 9 3 <
• 1.30 » 0.98 > • 061
¦ ¦ ¦ ¦ m
1.87
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
20.(
0
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
• Total
Figure 4-4. AnMBR, 35°C Reactor Temperature, Cumulative Energy Demand Results (MJ/m3 Wastewater Treated)
4-6
-------
4.0—Baseline Results
4.2.2 AnMBR Energy Results, 20°C Reactor Temperature
Figure 4-5 displays the AnMBR cumulative energy demand impacts on an annual basis
with the reactor operating at 20°C, while Figure 4-6 illustrates the same results per m3
wastewater treated basis. For the AnMBR operating at a lower reactor temperature, net energy
demand benefits are seen for all investigated scenarios. This scenario models an influent
temperature equivalent to the reactor temperature (20°C). Because of the lack of temperature
differential between the influent and reactor, no natural gas is required for heating the influent or
controlling heat loss. Electricity is still required for operating the pumps, but this is more than
offset by the recovery of biogas from the headspace of the reactor. This is the case even though a
lower quantity of biogas is produced at a lower reactor temperature. Detailed cumulative energy
demand results for all AnMBR scenarios operating at 20°C on an annual basis are presented in
Appendix A (Table A-l 1 through Table A-15).
4-7
-------
4.0—Baseline Results
0.05
MGD
0.05
0.1 MGD
1 MGD
AnMBR
0.05
0.05
MGD
AnMBR
0.1 MGD
AnMBR
1 MGD
5 MGD
10 MGD
[semi
MGD
MGD
AnMBR
[semi
0.1 MGD 0.1 MGD
AnMBR
[semi
1 MGD
1 MGD
AnMBR
5 MGD
5 MGD
AnMBR
10 MGD
10 MGD
AnMBR
rural
AnMBR
AnMBR
[high
rural
AnMBR
AnMBR
[high
rural
AnMBR
AnMBR
[high
AnMBR
AnMBR
[high
AnMBR
AnMBR
[high
single
[single
[multi
density
single
[single
[multi
density
single
[single
[multi
density
[single
[multi
density
[single
[multi
density
family]
family]
family]
urban]
family]
family]
family]
urban]
family]
family]
family]
urban]
family]
family]
urban]
family]
family]
urban]
50.000.000
X-,
-360.134 -385.867 -403.951 -407.542 -1.211.274-1.262.786 / -1.305.920
-1.298.739
-16.469.959 -16.913.720 -17.346.601-17.418.271
-50.000.000
III
^ -100.000.000
-150.000.000
-94.102.172 9
-95.886.467
¦96.245.560
-190.110.189 9
-200.000.000
¦ Wastewater collection
¦ Pre treatment
Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
• Total
/ !
-193.702.970 -194.422.694
-250.000.000
Figure 4-5. AnMBR, 20°C Reactor Temperature, Cumulative Energy Demand Results (MJ/Year)
4-8
-------
4.0—Baseline Results
15.00
10.00
5.00
£ 0.00
0.05
MGD 0.05 0.1 MGD 1 MGD
AiiMBR 0.05 0.05 MGD AiiMBR 0.1 MGD AiiMBR 1 MGD 5 MGD 10 MGD
[semi MGD MGD AiiMBR [semi 0.1 MGD 0.1 MGD AiiMBR [semi 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
rural AiiMBR AiiMBR [higli rural AiiMBR AiiMBR [high rural AiiMBR AiiMBR [high AiiMBR AiiMBR [high AiiMBR AiiMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
llllim
.....
-5.00
-10.00
-15.00
-5.21
-5.58
-5.84 • -5.90
-8.76
-9.13
-9.39 • -9.45
-11.9
-12.2
-12.5 • -12.6
"13-6 • -13.9 • -13.9 • -13.!
-14.0
-14.1
¦ Wastewater collection
¦ Pre treatment
Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
Displaced drinking water
• Total
-20.00
Figure 4-6. AnMBR, 20°C Reactor Temperature, Cumulative Energy Demand Results (MJ/m3 Wastewater Treated)
4-9
-------
4.0—Baseline Results
4.3 AeMBR Global Warming Potential Results
Global warming potential results for the AeMBR scenarios are displayed on an annual
basis and on m3 wastewater treated basis in Figure 4-7 and Figure 4-8, respectively. As the
primary greenhouse gases modeled in the system boundaries are related to energy usage in the
treatment system and upstream energy usage for production of cleaning chemicals, the global
warming potential results for the AeMBR scenarios follow the same trends as seen in the
cumulative energy demand analysis. Detailed global warming potential results for all AeMBR
scenarios on an annual basis are presented in Appendix A (Table A-16 through Table A-20).
4-10
-------
4.0—Baseline Results
0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 1 MGD 1 MGD 5 MGD 10 MGD
AeMBR 0.05 MGD0.05 MGD AeMBR AeMBR 0.1 MGD 0.1 MGD AeMBR AeMBR 1 MGD 1 MGD AeMBR 5 MGD 5 MGD AeMBR 10 MGD 10 MGD AeMBR
[semi rural AeMBR AeMBR [higli [semi rural AeMBR AeMBR [high [semi rural AeMBR AeMBR [high AeMBR AeMBR [high AeMBR AeMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
6.000.000
4.000.000
2.000.000
37.230 35.597 34.453 34225 16.390 13.144 10.865 10.410
O
o
-2.000.000
-4.000.000
-6.000.000
-464.890
t
•
•
/
-2.794.540
9
-2.906.708
-2.929.467
-5.775.714
9 ft
-6.003.517 _6.049.049
-8.000.000
-10.000.000
1 Wastewater collection ¦ Pre treatment MBR operation (electrical demand, chemicals) ¦ MBR infrastructure ¦ Post treatment ¦ Recycled water delivery Displaced drinking water •Total
-12.000.000
Figure 4-7. AeMBR Global Warming Potential Results (kg CO2 eq/Year)
4-11
-------
4.0—Baseline Results
0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 1 MGD 1 MGD 5 MGD
AeMBR 0.05 MGD0.05 MGD AeMBR AeMBR 0.1 MGD 0.1 MGD AeMBR AeMBR 1 MGD 1 MGD AeMBR 5 MGD 5 MGD AeMBR
[semi rural AeMBR AeMBR [high [semi rural AeMBR AeMBR [high [semi rural AeMBR AeMBR [high AeMBR AeMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban]
10 MGD
10 MGD 10 MGD AeMBR
AeMBR AeMBR [high
[single [multi density
family] family] urban]
1.50
1.00
mi
0.50
0.54
O 0.00
-0.50
051 • 0.50 • 0.50
mi
0.12
0 095 • 0.079 • 0.075
III
-0.34
-0.36
-0.38
-0.38
-0.40 « _o.42 • -0.42 • -0.42 » .0.43 .0.44
-1.00
1 Wastewater collection ¦ Pre treatment MBR operation (electrical demand, chemicals) ¦ MBR infrastructure ¦ Post treatment ¦ Recycled water delivery Displaced drinking water •Total
Figure 4-8. AeMBR Global Warming Potential Results (kg CO2 eq/m3 Wastewater Treated)
4-12
-------
4.0—Baseline Results
4.4 AnMBR Global Warming Potential Results
Figure 4-9 and Figure 4-10 display the AnMBR global warming potential results on a
yearly basis for a reactor operating at 35°C and 20°C, respectively. Similar results are shown per
m3 wastewater treated basis in Figure 4-11 and Figure 4-12. As the primary greenhouse gases
modeled in the system boundaries are related to energy usage in the treatment system and
upstream energy usage for production of cleaning chemicals, the global warming potential
results for the AnMBR scenarios (similar to the AeMBR scenarios) follow the same trends as
seen in the cumulative energy demand analysis. The one exception to this is the methane
emissions from permeate. Detailed global warming potential results for all AnMBR scenarios on
an annual basis are presented in Appendix A (Table A-21 through Table A-30).
4-13
-------
4.0—Baseline Results
20.000.000
15.000.000
1D.000.000
^.000.000
M. ¦
0.05
MGD 0.05 0.1 MGD 1 MGD
AiiMBR 0.05 0.05 MGD AiiMBR 0.1 MGD AiiMBR 1 MGD 5 MGD 10 MGD
[semi MGD MGD AiiMBR [semi 0.1 MGD 0.1 MGD AiiMBR [semi 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
rural AiiMBR AiiMBR [high rural AiiMBR AiiMBR [liigh rural AiiMBR AiiMBR [higli AiiMBR AiiMBR [high AiiMBR AiiMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
III
3.450.198
474.272 446.048 418.691 414.165 1.870.749
57.138 55.505 54.361 54J34 81_541 78.295 76.016 75.561 __ __ __
-5.000.000
-10.000.000
3.678.00
735.822
15.000.000
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
¦ Methane emissions from permeate
• Total
-20.000.000
Figure 4-9. AnMBR, 35°C Reactor Temperature, Global Warming Potential Results (kg CO2 eq/Year)
4-14
-------
4.0—Baseline Results
0.05
MGD 0.05 0.1 MGD 1 MGD
AiiMBR 0.05 0.05 MGD AiiMBR 0.1 MGD AiiMBR 1 MGD 5 MGD 10 MGD
[semi MGD MGD AiiMBR [semi 0.1 MGD 0.1 MGD AiiMBR [semi 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
rural AiiMBR AiiMBR [higli rural AiiMBR AiiMBR [high rural AiiMBR AiiMBR [higli AiiMBR AiiMBR [higli AiiMBR AiiMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
10.000.000
5.000.000
—
O
o
7.264 5.631 448j 4259 .17,730 -20.977 -23.255 -23.710
-5.000.000
-10.000.000
-510.535
-538.759 -566.116 -570
¦ Wastewater collection
¦ Pre treatment
Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
Displaced drinking water
¦ Methane emissions from permeate
• Total
6.151.875
-3.167.753 -3.190.512
-15.000.000
-6.379.677 -6.425.209
Figure 4-10. AnMBR, 20°C Reactor Temperature, Global Warming Potential Results (kg CO2 eq/Year)
4-15
-------
4.0—Baseline Results
0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 1 MGD 1 MGD 5 MGD 10 MGD
AiiMBR 0.05 MGD0.05 MGD AiiMBR AiiMBR 0.1 MGD 0.1 MGD AiiMBR AiiMBR 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
[semi rural AiiMBR AiiMBR [high [semi rural AiiMBR AiiMBR [higli [semi rural AiiMBR AiiMBR [higli AiiMBR AiiMBR [higli AiiMBR AiiMBR [liigh
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
2.00
, IINliiiiiiiimii
43 • 0.83 t 0 80 # 0 79 # 0 78
£ rrrr™*:-.-
llllllllllllllllll
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
1 Displaced drinking water
¦ Methane emissions from permeate
• Total
Figure 4-11. AnMBR, 35°C Reactor Temperature, Global Warming Potential Results (kg CO2 eq/ m3 Wastewater Treated)
4-16
-------
4.0—Baseline Results
0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 1 MGD 1 MGD 5 MGD 10 MGD
AiiMBR 0.05 MGD0.05 MGD AiiMBR AiiMBR 0.1 MGD 0.1 MGD AiiMBR AiiMBR 1 MGD 1 MGD AiiMBR 5 MGD 5 MGD AiiMBR 10 MGD 10 MGD AiiMBR
[semi rural AiiMBR AiiMBR [high [semi rural AiiMBR AiiMBR [high [semi rural AiiMBR AiiMBR [high AiiMBR AiiMBR [higli AiiMBR AiiMBR [high
single [single [multi density single [single [multi density single [single [multi density [single [multi density [single [multi density
family] family] family] urban] family] family] family] urban] family] family] family] urban] family] family] urban] family] family] urban]
1.50
¦ Wastewater collection
¦ Pre treatment
1 Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
Displaced drinking water
¦ Methane emissions from permeate
• Total
Figure 4-12. AnMBR, 20°C Reactor Temperature, Global Warming Potential Results (kg CO2 eq/ m3 Wastewater Treated)
4-17
-------
4.0—Baseline Results
4.5 Energy Demand and Global Warming Potential Comparative Scenario Analysis
Comparative energy demand results for the AeMBR and the AnMBR run at both 35°C
and 20°C for the multi family land use scenario are illustrated in Figure 4-13 and Figure 4-14 on
the basis of a year of operation and a cubic meter of wastewater treated respectively. In all cases,
the AnMBR operated at 20°C results in the lowest energy demand impacts followed by the
AeMBR, and then the AnMBR operated at 35°C. Net energy benefits, considering the displaced
drinking water by the delivered recycled water, start at the 1 MGD scale for the AeMBR and at
the 5 MGD scale for the AnMBR operated at 35°C. For all scales investigated, the AnMBR
reactor operated at 20°C results in the most net energy benefits due to no heating of influent and
the ability to recovery biogas for operation. When examining the energy demand results
normalized to a cubic meter of water treated, all energy demand impacts decrease as the scale
increases.
As discussed in Section 4.3 and Section 4.4, the global warming potential results follow
the same trends as the energy demand results, with the exception of methane emissions from the
permeate. Figure 4-15 and Figure 4-16 display the comparative global warming potential results
for the AeMBR and the AnMBR run at both 35°C and 20°C for the multi family land use
scenario on the basis of a year of operation and a cubic meter of wastewater treated respectively.
4-18
-------
4.0—Baseline Results
250.000.000
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
AnMBR©
AnMBR ©
AnMBR©
AnMBR ©
AnMBR ©
AnMBR©
AnMBR©
AnMBR©
AnMBR©
AnMBR ©
AeMBR 35 C
20 C
AeMBR 35 C
20 C
AeMBR 35 C
20 C
AeMBR 35 C
20 C
AeMBR 35 C
20 C
200.000.000
150.000.000
100.000.000
50.000.000
-------
4.0—Baseline Results
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
l"
B 761 *7.51 1
i
ii
|
3.91 |
l •()(,(, L
.¦ J-l
1 X
M 11
¦ I
• -5.84
¦
•
• -9.39
l ¦ l
-5.52
¦ 1
• -6.87
• -12.5
|).68 |
•
• -13.9
• j).82
-7.09
• -14.
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
• Total
Figure 4-14. AeMBR and AnMBR Energy Demand Comparison for Multi Family Land Use (MJ/m3 Wastewater Treated)
4-20
-------
4.0—Baseline Results
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
15.000.000
10.000.000
5.000.000
Sa
u 0
o
o
M
M.
-5.000.000
-10.000.000
-15.000.000
¦ Wastewater collection
¦ Pre treatment
¦ Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
¦ Methane emissions from permeate
• Total
Figure 4-15. AeMBR and AnMBR Global Warming Potential Comparison for Multi Family Land Use (kg CO2 eq/Year)
_
54.361 f 10.865 f 76.016
34.453 | 4.487
I
10.865 /'
418.691
-23.255 L .520.472
-566.116
3.450.198
1.758.581
¦ ' I
mini
-2.906.708
£ f\f\t ^1-7
-3.167.753
-6.379.677
4-21
-------
4.0—Baseline Results
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
AnMBR© AnMBR©
AeMBR 35 C 20 C
f]
¦ .50
I"
~ 0.79 1
_ wm.oe 1
|
1 1
H.079 |
1
1 ¦ l
\ |
' 0 30 l l # 0 25 l
E
1 ¦
"I
m" ¦ ¦
• "°-38 • -0.41 •
-0.42 # _0 46 • -0.43 « .Q.46
-2
¦ Wastewater collection
¦ Pre treatment
Heating of influent
¦ Heat loss control
¦ MBR operation (electrical demand, chemicals)
¦ Recovery of methane from headspace
¦ MBR infrastructure
¦ Post treatment
¦ Recycled water delivery
¦ Displaced drinking water
¦ Methane emissions from permeate
• Total
Figure 4-16. AeMBR and AnMBR Global Warming Potential Comparison for Multi Family Land Use (kg CO2 eq/m3
Wastewater Treated)
4-22
-------
4.0—Baseline Results
4.6 Net Water Savings and other Potential Benefits
While this study focuses on energy demand and GHG impacts of the decentralized MBR
systems, there is a potential significant water savings from using recycled wastewater. This study
found that use of recycled water from decentralized MBR scenarios avoids 0.94 to 0.96 cubic
meters of fresh water per cubic meter of wastewater treated by MBR as displayed in Table 4-1.
Results are not shown by life cycle stage or by scale scenario since, as can be seen in the first
row of Table 4-1, the recycled water displacement of potable water dwarfs the operational
impacts.
Table 4-1. Water Savings (m3 Water Consumed/m3 Wastewater Treated)
AeMBR
AnMBR
Displaced drinking water
-0.95
-0.96
Operational/infrastructure requirements *
0.002 to 0.0077
0.0004 to 0.0029
Net total
-0.94
-0.95 to -0.96
*Varies by scale.
Not all benefits that are possible with a centralized or fully decentralized resource recovery
system can be captured when modeling transitional AnMBR WWT and recycled water systems.
While the transitional systems can capture the benefits of water reuse and, in case of AnMBR,
energy recovery, returning the sludge for treatment at the downstream centralized WWTP
removes the possibility of nutrient recovery from sludge for use as fertilizer. In addition, because
final solids handling is carried out at the centralized WWTP where any change in sludge
received due to the operation of the transitional systems is assumed to have a negligible impact
on the centralized WWTP's operations, it is not possible to assess the potential benefits of lower
sludge production by the AnMBR system compared to the AeMBR system (see Table 4-2) or in
comparison to conventional aerobic activated sludge treatment.
Table 4-2. Comparison of Sludge Output by AeMBR and AnMBR systems
AcIMBR Sludge
Output (MGD)
AnMBR Sludge
Output (MGD)
0.05 MGD
0.0012
0.00063
0.1 MGD
0.0023
0.0012
1 MGD
0.023
0.0084
5 MGD
0.12
0.037
10 MGD
0.23
0.077
4.7 Cost Analysis Results
The cost analysis results are presented in the following sections, with results shown
separately for the AeMBR WWTP, the 20°C AnMBR WWTP, the 35°C AnMBR WWTP, the
recycled water delivery system, and the avoided costs for drinking water treatment and
distribution for each scale and density. The last two sections provide total costs for the combined
WWTP, recycled water delivery, and avoided DWT costs for each scale and density. Detailed
results tables corresponding to each figure are provided in Appendix C.
4-23
-------
4.0—Baseline Results
4.7.1 Cost Analysis Results for Aerobic MBR Wastewater Treatment Plant
The yearly expenses for plant construction and operation of the AeMBR at the different
scales examined are displayed in Figure 4-17. The same expenses are presented in Figure 4-18
on a per cubic meter (m3) of treated wastewater basis. In terms of the impact of scale, the
relationship between yearly expenses and expenses per m3 treated wastewater are inversely
proportional. The 10 MGD system has the highest overall yearly costs, but the lowest costs on a
MGD basis. In all cases, the greatest portion of the cost, ranging from 40% for the 0.05 MGD
system to 63% for the 10 MGD system, is the amortized value of the construction and equipment
installation costs. The cost of labor for operating the plant is high, accounting for 40% of total
annual cost for the 0.05 MGD plant but only 20% for the 10 MGD plant. Maintenance,
purchased energy, materials, and chemicals are each 10% or less of total costs, regardless of the
scale considered.
$8,000,000
$7,000,000
$6,000,000
$5,000,000
$4,000,000
$3,000,000
$2,000,000
$1,000,000
$0
0.05 MGD 0.1 MGD 1 MGD 5 MGD 10 MGD
lOperation ¦Maintenance ¦ Materials I Chemicals ¦ Energy ¦Amortized Capital Cost
Figure 4-17. Yearly Expenses for AeMBR Facility by Scale
4-24
-------
4.0—Baseline Results
$8.00
$7.00
$6.00
$5.00
$4.00
$3.00
$2.00
$1.00
$0.00
0.05 MGD 0.1 MGD 1MGD 5 MGD 10MGD
¦ Operation ¦Maintenance ¦ Materials ¦ Chemicals ¦ Energy ¦ Amortized Capital Cost
Figure 4-18. Expenses for AeMBR Facility by Scale per m3 Wastewater Treated
4.7.2 Cost Analysis Results for Anaerobic MBR Wastewater Treatment Plant
The yearly expenses for plant construction and operation of the AnMBR operating at
35°C and 20°C at the different scales examined are displayed in Figure 4-19 and Figure 4-20,
respectively. The same expenses per m3 treated wastewater basis are provided in Figure 4-21 and
Figure 4-22. As for the AeMBR cost analysis results, the relationship between yearly expenses
and expenses on per m3 treated wastewater basis are inversely proportional. The 10 MGD system
has the highest overall yearly costs, but the lowest costs on a MGD basis. Operation labor and
amortized capital costs contribute a roughly equal share, 30-40% each, of the total cost for the
AnMBR WWTPs. The percent contribution of operation labor and capital costs drop slightly for
scales 1 MGD and greater. For the 35°C operating scenario, purchased energy makes up a larger
portion of the total costs compared to energy costs for the AeMBR WWTPs. However, this
percentage is lower for the 20°C operating scenario since purchase of natural gas is not
necessary. Some cost benefits are realized from electricity generation for both 35°C and 20°C
operating scenarios. The net energy cost differential between the AnMBR operating at 35°C and
at 20°C is illustrated in Table 4-3.
4-25
-------
4.0—Baseline Results
$25,000,000
$20,000,000
$15,000,000
$10,000,000
$5,000,000
$0
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
-$5,000,000
I Operation ¦ Maintenance ¦ Materials ¦ Chemicals
iEnergy Demand ¦ Electricity Generated ¦Amortized Capital Cost
Figure 4-19. Yearly Expenses for the 35°C AnMBR Facility by Scale
$20,000,000
$15,000,000
$10,000,000
$5,000,000
$0
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
-$5,000,000
I Operation ¦ Maintenance ¦ Materials ¦ Chemicals
iEnergy Demand ¦ Electricity Generated ¦Amortized Capital Cost
Figure 4-20. Yearly Expenses for the 20°C AnMBR Facility by Scale
4-26
-------
4.0—Baseline Results
$10.00
$8.00
$6.00
$4.00
$2.00
$0.00
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
-$2.00
i Operation ¦Maintenance "Materials ¦ Chemicals
I Energy Demand ¦ Electricity Generated ¦ Amortized Capital Cost
Figure 4-21. Expenses for the 35°C AnMBR Facility by Scale per m3 Wastewater Treated
4-27
-------
4.0—Baseline Results
$10.00
$9.00
$8.00
$7.00
$6.00
$5.00
$4.00
$3.00
$2.00
$1.00
$0.00
0.05 MGD 0.1 MGD 1MGD 5 MGD 10MGD
-$1.00
¦ Operation ¦Maintenance ¦ Materials ¦ Chemicals
¦ Energy Demand ¦ Electricity Generated ¦Amortized Capital Cost
Figure 4-22. Expenses for the 20°C AnMBR Facility by Scale per m3 Wastewater Treated
Table 4-3. AnMBR Annual Energy Cost Differential between Operating at 35°C and 20°C
0.05 MGD
0.1 MGD
1 MGD
5 MGD
10 MGD
(@,35 C
16,855
20,795
157,948
753,397
1,493,928
(8>. 20 C
3,155
2,146
-26,728
-168,380
-348,631
Percent Decrease
-81%
-90%
-117%
-122%
-123%
4.7.3 Cost Analysis Results for Recycled Water Distribution System
Figure 4-23 and Figure 4-24 show the yearly costs for constructing and operating the
recycled water distribution system. As expected, the greater the amount of water delivered, the
greater the costs. In addition, when holding the amount of people served constant, distribution
system costs increase as the density of the service area decreases.
4-28
-------
4.0—Baseline Results
$140,000
$120,000
$100,000
$80,000
$60,000
$40,000
$20,000
$0
I
0.05 MGD 0.05 MGD 0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 0.1 MGD 0.1 MGD
[semi rural [single [multi [high [semi rural [single [multi [high
single family] family] density single family] family] density
family] urban] family] urban]
¦ Amortized Capital Cost BO&MCost "Energy Cost
Figure 4-23. Yearly Life Cycle Costs for Recycled Water Delivery System for Each Density
Scenario Associated with the 0.05 and 0.1 MGD Scales
$7,000,000
$6,000,000
$5,000,000
$4,000,000
$3,000,000
$2,000,000
$1,000,000
$0
1 MGD 1 MGD 1 MGD 1 MGD 5 MGD 5 MGD 5 MGD 10 MGD 10 MGD 10 MGD
[semi [single [multi [high [single [multi [high [single [multi [high
rural family] family] density family] family] density family] family] density
single urban] urban] urban]
family]
¦ Amortized Capital Cost ¦ O&M Cost ¦ Energy Cost
Figure 4-24. Yearly Life Cycle Costs for Recycled Water Delivery System for Each Density
Scenario Associated with the 1, 5, and 10 MGD Scales
1
1
1 ¦ - I
J
1.
4-29
-------
4.0—Baseline Results
4.7.4 Avoided Costs from Drinking Water Treatment and Distribution
This cost analysis includes the savings that result from reducing the amount of water that
must be treated at the centralized drinking water treatment facility and then distributed for use by
displacing drinking water with recycled water. Avoided amortized capital, O&M, and energy
costs for each scale are based on an EPA life cycle cost analysis of Greater Cincinnati Water
Works and are summarized in Table 4-4 and Table 4-5 for the AeMBR and AnMBR WWT
systems, respectively (Cashman et al., 2014a). Avoided costs are greater for the AnMBR systems
since a greater quantity of influent wastewater is recovered and recycled. Note the avoided costs
for the drinking water treatment and distribution include ongoing maintenance and labor but do
not include expenditures on previously purchased capital goods since those are sunk costs.
Table 4-4. Drinking Water Treatment and Distribution Costs Avoided by AeMBR WWT
and Recycled Water Delivery System
0.05 mcd
0.1 MCI)
1 M(.l)
5 MCI)
10 MCI)
Amortized Capital Cost
-2
-4
-37
-186
-372
O&M Cost
-2,558
-5,116
-51,159
-255,795
-511,590
Energy Cost
-1,863
-3,726
-37,264
-186,322
-372,644
Total
-4,423
-8,846
-88,461
-442,303
-884,606
Table 4-5. Drinking Water Treatment and Distribution Costs Avoided by AnMBR WWT
and Recycled Water Delivery System
0.05 MCI)
0.1 MCI)
1 MCI)
5 MCI)
10 MCI)
Amortized Capital Cost
-4
-38
-IX<>
-¦?"s
O&M Cost
-2,585
-5,175
-51,934
-259,933
-519,708
Energy Cost
-1,883
-3,770
-37,829
-189,336
-378,557
Total
-4,471
-8,949
-89,801
-449,457
-898,643
4.7.5 Combined AeMBR WWTP, Recycled Water Delivery System, and Avoided DWT
Cost Analysis Results
The combined annual costs for constructing and operating the AeMBR WWTP and
recycled water distribution system as well as avoided drinking water treatment and delivery costs
for all scale and density scenarios are presented in Figure 4-25 and Figure 4-26. Across all of the
scenarios, O&M and capital costs combined are responsible for roughly 90% or more of the
overall cost of the system. The share of expenses due to O&M decreases with increasing scale,
while the share for capital costs increase. In all cases, the total cost for a system of a particular
scale will be less than the total cost for a larger scale, regardless of the density of the service
area. Scenarios with lower density service areas are costlier than scenarios of the same scale with
higher density service areas due to increased infrastructure to deliver recycled water over greater
distances. Figure 4-27 highlights how cost effectiveness improves dramatically as the system
scale increases from 0.05 MGD to 0.1 MGD and from 0.1 MGD to 1 MGD, mainly due to
economies of scale achieved for the WWTP O&M labor and capital costs, but cost effectiveness
4-30
-------
4.0—Baseline Results
improvements are small between the 1 MGD, 5 MGD, and 10 MGD systems. Because
wastewater treatment contributes a much smaller portion of overall costs at scales of 1 MGD and
larger, a change in service area density has a greater impact on overall system cost. For example,
overall cost per cubic meter of treated wastewater for a 10 MGD system serving single family
homes is higher than for a 5 MGD system serving high-density urban or multi family homes.
$800,000
$700,000
$600,000
$500,000
$400,000
$300,000
$200,000
$100,000
$0
-$100,000
0.05 MGD
[semi rural
single
family]
0.05 MGD
[single
family]
0.05 MGD
[multi
family]
0.05 MGD
[high density
urban]
0.1 MGD
[semi rural
single
family]
0.1 MGD
[single
family]
0.1 MGD
[multi
family]
0.1 MGD
[high density
urban]
¦ Amortized Capital Cost BO&MCost ¦ Energy Cost I Avoided DWT Cost ~Total
Figure 4-25. Combined Annual AeMBR, Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD Scales
4-31
-------
4.0—Baseline Results
$15,000,000
$13,000,000
$11,000,000
$9,000,000
$7,000,000
$5,000,000
$3,000,000
$1,000,000
-$1,000,000
1MGD 1MGD 1MGD 1MGD 5 MGD 5 MGD 5 MGD 10MGD 10MGD 10MGD
[semi rural [single [multi [high [single [multi [high [single [multi [high
single family] family] density family] family] density family] family] density
family] urban] urban] urban]
¦ Amortized Capital Cost BO&MCost ¦ Energy Cost I Avoided DWT Cost ~Total
Figure 4-26. Combined Annual AeMBR, Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD Scales
$9.00
$8.00
$7.00
$6.00
$5.00
$4.00
$3.00
$2.00
$1.00
$0.00
-$1.00
• . . .
Ilia
0.05
MGD
[semi
rural
single
family]
0.05 0.05 0.05 0.1 0.1 0.1 0.1 1 1 1 1 5 5 5 10 10 10
MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD
[single [multi [high [semi [single [multi [high [semi [single [multi [high [single [multi [high [single [multi [high
family] family] density rural family] family] density rural family] family] density family] family] density family] family] density
urban] single urban] single urban] urban] urban]
family] family]
¦ Amortized Capital Cost bO&M Costs ¦ Energy Cost Avoided DWT Cost ~Total
Figure 4-27. Combined AeMBR, Recycled Water Delivery, and Avoided DWT Costs for
Each Density and Scale Scenario per m3 of Treated Wastewater
4-32
-------
4.0—Baseline Results
4.7.6 Combined AnMBR WWTP and Recycled Distribution System Cost Analysis Results
The yearly costs for constructing and operating the AnMBR WWTP, recycled water
distribution system, and the avoided drinking water treatment and distribution costs for all scale
and density scenarios are presented in Figure 4-28 and Figure 4-29 for the AnMBR operating at
35 °C and in Figure 4-31 and Figure 4-32 for the AnMBR operating at 20 °C. As shown in the
figures, operation and maintenance and capital costs are the biggest contributors to the overall
cost of the system. Even though a system installed in a lower density area would be more
expensive, the wastewater treatment facility is the main driver of overall costs, meaning the
larger the scale, the greater the cost, regardless of the density of the service area. In general, the
overall costs for AnMBR systems are more expensive than the AeMBR systems. This is largely
due to the cost of increased labor required to operate the anaerobic reactor system as well as the
high quantity of membrane required since AnMBR operates at a much lower average net flux
than the AeMBR. Combined cost results are shown on a per m3 of treated wastewater basis in
Figure 4-30 for scenarios with a 35 °C AnMBR and in Figure 4-33 for scenarios with a 20 °C
AnMBR. Both of these figures follow the same pattern observed for the AeMBR results on a per
m3 treated wastewater basis.
$1,000,000
$900,000
$800,000
$700,000
$600,000
$500,000
$400,000
$300,000
$200,000
$100,000
$0
-$100,000
0.05 MGD 0.05 MGD 0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 0.1 MGD 0.1 MGD
[semi rural [single [multi [high density [semi rural [single [multi [high density
single family] family] urban] single family] family] urban]
family] family]
¦ Amortized Capital Cost BO&M Costs ¦ Energy Cost ¦ Avoided DWT Cost ~Total
Figure 4-28. Combined Annual AnMBR (35 °C), Recycled Water Delivery, and Avoided
DWT Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD Scales
4-33
-------
4.0—Baseline Results
$27,500,000
$25,000,000
$22,500,000
$20,000,000
$17,500,000
$15,000,000
$12,500,000
$10,000,000
$7,500,000
$5,000,000
$2,500,000
$0
-$2,500,000
I > i a
1MGD 1MGD 1MGD 1MGD
[semi rural [single [multi [high
single family] family] density
family] urban]
¦ Amortized Capital Cost ¦ O&M Costs
5 MGD 5 MGD 5 MGD 10 MGD 10 MGD 10 MGD
[single [multi [high [single [multi [high
family] family] density family] family] density
urban] urban]
¦ Energy Cost ¦AvoidedDWT Cost ~Total
Figure 4-29. Combined Annual AnMBR (35 °C), Recycled Water Delivery, and Avoided
DWT Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD Scales
$11.00
$10.00
$9.00
$8.00
$7.00
$6.00
$5.00
$4.00
$3.00
$2.00
$1.00
$0.00
0.05
-$1.00 MGD
[semi
rural
single
family]
I I I I I I I
0.05 0.05 0.05 0.1 0.1 0.1 0.1 1 1 1 1 5 5 5 10 10 10
MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD
[single [multi [high [semi [single [multi [high [semi [single [multi [high [single [multi [high [single [multi [high
family]family] density rural family] family] density rural family] family] densityfamily] family] densityfamily] family] density
urban] single urban] single urban] urban] urban]
family] family]
¦ Amortized Capital Cost ¦ O&M Costs ¦ Energy Cost ¦ Avoided DWT Cost ~Total
Figure 4-30. Combined AnMBR (35 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density and Scale Scenario per m3 of Treated Wastewater
4-34
-------
4.0—Baseline Results
$900,000
$800,000
$700,000
$600,000
$500,000
$400,000
$300,000
$200,000
$100,000
$0
-$100,000
0.05 MGD 0.05 MGD 0.05 MGD 0.05 MGD 0.1 MGD 0.1 MGD 0.1 MGD 0.1 MGD
[semi rural [single [multi [high density [semi rural [single [multi [high density
single family] family] urban] single family] family] urban]
family] family]
¦ Amortized Capital Cost BO&M Costs ¦ Energy Cost I Avoided DWT Cost ~Total
Figure 4-31. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 0.05 and 0.1 MGD Scales
$25,000,000
$22,500,000
$20,000,000
$17,500,000
$15,000,000
$12,500,000
$10,000,000
$7,500,000
$5,000,000
$2,500,000
$0
-$2,500,000
I I a i
1 MGD 1 MGD 1 MGD 1 MGD 5 MGD 5 MGD
[semi rural [single [multi [high [single [multi
single family] family] density family] family]
family] urban]
¦ Amortized Capital Cost BO&M Costs ¦ Energy Cost
5 MGD 10 MGD 10 MGD 10 MGD
[high [single [multi [high
density family] family] density
urban] urban]
Avoided DWT Cost ~Total
Figure 4-32. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density Scenario Associated with the 1, 5, and 10 MGD Scales
4-35
-------
4.0—Baseline Results
$10.00
$9.00
$8.00
$7.00
$6.00
$5.00
$4.00
$3.00
$2.00
$1.00
$0.00
0.05 0.05 0.05 0.05 0.1 0.1 0.1 0.1 1 1 1 1 5 5 5 10 10 10
-$1.00 MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD MGD
[semi [single [multi [high [semi [single [multi [high [semi [single [multi [high [single [multi [high [single [multi [high
rural family]family] density rural family] family] density rural family] family] densityfamily] family] densityfamily] family] density
single urban] single urban] single urban] urban] urban]
family] family] family]
¦ Amortized Capital Cost ¦ O&M Costs ¦ Energy Cost Avoided DWT Cost ~Total
Figure 4-33. Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided DWT
Costs for Each Density and Scale Scenario per m3 of Treated Wastewater
4.7.7 Cost Comparative Scenario Analysis
Comparative AeMBR and AnMBR costs are shown for the multi family land use
scenario on an annual basis in Figure 4-34 and on a per cubic meter of wastewater treated in
Figure 4-35. These figures include WWTP operation, recycled water delivery, and avoided
drinking water costs. AnMBR costs are notably higher than the AeMBR costs. This is primarily
from differences in O&M costs between the AeMBR and AnMBR systems. The driver for this is
the increase in O&M labor needed to operate the anaerobic reactor system.
4-36
-------
4.0—Baseline Results
25
20
15
>H
10
2 5
.1
I
0.05 0.1 1 MGD5MGD 10 0.05 0.1 1 MGD5 MGD 10 0.05 0.1 1 MGD5 MGD 10
MGD MGD MGD MGD MGD MGD MGD MGD MGD
_5 AeMBR AnMBR (S> 35 AnMBR (S> 20
¦ Amortized Capital Cost BO&MCosts ¦ Energy Cost I AvoidedDWT Cost #Net Total
Figure 4-34. Comparative Yearly MBR Costs for Multi Family Land Use Scenario
10.0
8.0
6.0
H
£ 4.0
2.0
0.0
-2.0
III
III
0.05 0.1 1 MGD5 MGD 10 0.05 0.1 1 MGD5 MGD 10 0.05 0.1 1 MGD5 MGD 10
MGD MGD MGD MGD MGD MGD MGD MGD MGD
AeMBR AnMBR @35 AnMBR @ 20
¦ Amortized Capital Cost BO&MCosts ¦ Energy Cost "Avoided DWT Cost #NetTotal
Figure 4-35. Comparative MBR Costs per m3 of Treated Wastewater for Multi Family
Land Use Scenario
4-37
-------
5.0—Sensitivity Analyses
5.0 Sensitivity Analyses
Sensitivity analysis is an important component in the production of robust LCA study
results. As with any modeling process, the construction and analysis of an LCA model and
results requires making and documenting many assumptions. Many individual assumptions are
known to have only an insignificant effect on the final impact results calculated for a given
functional unit, but the effects of other assumptions are uncertain or are known to be significant.
In the latter two cases, sensitivity analysis is employed to quantify the effect of modeling choices
on LCA results. To increase the robustness of the study, the following sensitivity analyses were
conducted on parameters determined to be important after reviewing the baseline findings.
• Inclusion of CHP unit for the AnMBR;
• Flaring of biogas rather than recovery for methane for AnMBR;
• Inclusion of two climate scenarios for psychrophilic AnMBR:
— Variability in both the ambient air temperature, reactor temperature and
influent wastewater temperature.
— Calculations with and without reactor insulation for each climate scenario.
— Examination of dissolved methane in the permeate and the potential impacts
and benefits of recovering this methane within different climates.
• Incorporation of a range of displaced potable water scenarios based on a literature
review (both aerobic MBR and AnMBR scenarios); and
• Incorporation of different regional electrical grid mixes for both MBR operation and
the treatment and delivery of displaced potable water.
5.1 Climate and Methane Recovery Scenarios
Table 5-1 provides detailed descriptions of the scenario abbreviations used in the climate
and methane recovery sensitivity analysis results' display. Two specific climate scenarios are run
under multiple conditions. AnMBR operation is considered in the winter time in a cold climate
Cincinnati, Ohio (abbreviated CN) and for the annual average in a warm climate Miami, Florida
(abbreviated MIA). These scenario analyses have only been conducted for the psychrophilic
AnMBR, as the psychrophilic AnMBR showed the most promise in the baseline results from an
energy and global warming potential perspective. Key differentiating parameters for the
scenarios are indicated Table 5-1. These differentiating parameters include the ambient
temperature, influent wastewater temperature, reactor temperature, whether reactor surface
insulation is included, whether methane is recovered from the permeate, and whether methane
recovered from permeate/headspace is flared, converted to electricity only, or converted to both
electricity and heat via CHP. A discussion of the ambient and influent temperatures used is
provided in Appendix D.
5-1
-------
5.0—Sensitivity Analyses
Table 5-1. Full and Abbreviated Names of Climate and Methane
Recovery Scenarios and Associated Differentiating Parameters
Methane Recovery Option
Scenario Abbreviations
Scenario Full Name
Ambient T ( C)
Influent T ( C)
Reactor T ( C)
Reactor
Insulation
Flared
Converted
to
Electricity
Only
CHP
Methane
Permeate
Recovery
CN winter no insulation;
biogas flare; no methane
biogas recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
is flared; no recovery of methane
from permeate
6.0
17.9
20.0
V
CN winter w/ insulation;
biogas flare; no permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is flared; no
recovery of methane from permeate
6.0
17.9
20.0
V
V
CN winter no insulation;
elect; no permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
is converted to electricity; no
recovery of methane from permeate
6.0
17.9
20.0
V
CN winter w/ insulation;
elect; no permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is converted to
electricity; no recovery of methane
from permeate
6.0
17.9
20.0
V
V
CN winter no insulation;
CHP; no permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
is converted to electricity and heat
via CHP; no recovery of methane
from permeate
6.0
17.9
20.0
V
CN winter no insulation;
biogas flare; permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
6.0
17.9
20.0
V
V
5-2
-------
5.0—Sensitivity Analyses
Table 5-1. Full and Abbreviated Names of Climate and Methane
Recovery Scenarios and Associated Differentiating Parameters
Methane Recovery Option
Scenario Abbreviations
Scenario Full Name
Ambient T ( C)
Influent T ( C)
Reactor T ( C)
Reactor
Insulation
Flared
Converted
to
Electricity
Only
CHP
Methane
Permeate
Recovery
is flared; recovery of methane from
permeate
CN winter w/ insulation;
CHP; no permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is converted to
electricity and heat via CHP; no
recovery of methane from permeate
6.0
17.9
20.0
V
V
CN winter w/ insulation;
biogas flare; permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is flared; recovery
of methane from permeate
6.0
17.9
20.0
V
V
V
CN winter no insulation;
elect; permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
is converted to electricity; recovery
of methane from permeate
6.0
17.9
20.0
V
V
CN winter w/ insulation;
elect; permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is converted to
electricity; recovery of methane
from permeate
6.0
17.9
20.0
V
V
V
CN winter no insulation;
CHP; permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions; no
reactor insulation; recovered biogas
is converted to electricity and heat
via CHP; recovery of methane from
permeate
6.0
17.9
20.0
V
V
5-3
-------
5.0—Sensitivity Analyses
Table 5-1. Full and Abbreviated Names of Climate and Methane
Recovery Scenarios and Associated Differentiating Parameters
Methane Recovery Option
Scenario Abbreviations
Scenario Full Name
Ambient T ( C)
Influent T ( C)
Reactor T ( C)
Reactor
Insulation
Flared
Converted
to
Electricity
Only
CHP
Methane
Permeate
Recovery
CN winter w/ insulation;
CHP; permeate methane
recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Cincinnati, OH winter conditions;
with insulation on reactor surface;
recovered biogas is converted to
electricity and heat via CHP;
recovery of methane from permeate
6.0
17.9
20.0
V
V
V
MIA; biogas flare; no
permeate methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Miami, FL annual conditions;
recovered biogas is flared; no
recovery of methane from permeate
26.4
26.4
26.4
V
MIA; elect; no permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Miami, FL annual conditions;
recovered biogas is converted to
electricity; no recovery of methane
from permeate
26.4
26.4
26.4
V
MIA; biogas flare; permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Miami, FL annual conditions;
recovered biogas is flared; recovery
of methane from permeate
26.4
26.4
26.4
V
V
MIA; CHP; no permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Miami, FL annual conditions;
recovered biogas is converted to
electricity and heat via CHP; no
recovery of methane from permeate
26.4
26.4
26.4
V
MIA; elect; permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
Miami, FL annual conditions;
recovered biogas is converted to
electricity; recovery of methane
from permeate
26.4
26.4
26.4
V
V
MIA; CHP; permeate
methane recovery
1 MGD AnMBR serving 10,000
people at 50,000 people/sq. mi;
26.4
26.4
26.4
V
V
5-4
-------
5.0—Sensitivity Analyses
Table 5-1. Full and Abbreviated Names of Climate and Methane
Recovery Scenarios and Associated Differentiating Parameters
Methane Recovery Option
Scenario Abbreviations
Scenario Full Name
Ambient T ( C)
Influent T ( C)
Reactor T ( C)
Reactor
Insulation
Flared
Converted
to
Electricity
Only
CHP
Methane
Permeate
Recovery
Miami, FL annual conditions;
recovered biogas is converted to
electricity and heat via CHP;
recovery of methane from permeate
CN = Cincinnati, MIA = Miami
5-5
-------
5.0—Sensitivity Analyses
5.1.1 Cumulative Energy Demand Results for Climate and Methane Recovery Scenarios
Figure 5-1 displays the detailed cumulative energy demand results for AnMBR climate
scenarios. Scenarios are ordered by highest to lowest net energy demand. As can be seen in this
figure, net cumulative energy demand benefits are realized for all scenarios except Cincinnati
winter scenarios with only biogas flare and no reactor surface insulation. The largest cumulative
energy demand benefits are from displaced potable water and recovery of methane in headspace.
Less key cumulative energy demand benefits are for inclusion of reactor surface insulation and
recovery of methane from permeates. The most burdensome energy impact is for heating of
influent under Cincinnati winter conditions. The optimal scenario investigated from an energy
perspective is the psychrophilic AnMBR operated in warm climate (e.g., Miami, FL) with
methane recovery via CHP and both headspace and permeate methane recovery.
5-6
-------
5.0—Sensitivity Analyses
25,000,000
20,000,000
15,000,000
10,000,000
5,000,000
0
-5,000,000
-10,000,000
-15,000,000
-20,000,000
-25,000,000
-30,000,000
03
*? ¦ S>" & 2> . o<>- . 0V J> ^ A>^ ^
>¦ .¦* ^ ^ f / / / / / / ^ jf * ^
* ^
^ ,0^
~ ^ ./ ,~ ./
sv
-------
5.0—Sensitivity Analyses
5.1.2 Global Warming Potential Results for Climate and Methane Recovery Scenarios
Figure 5-2 presents the detailed global warming potential results for AnMBR climate
scenarios. Results are similar to those seen for the energy demand with the exception of
permeates methane emissions. Inclusion of permeate methane recovery avoids 80% of the
permeate methane emissions. Some key findings for this sensitivity analysis include:
• Net global warming potential benefits realized for all Miami, FL (warm climate)
scenarios;
• Net global warming potential benefits are only seen for cold climate scenario only
when dissolved methane in permeate is recovered, and methane in
headspace/permeate is converted to electricity or electricity in heat (i.e., methane is
not flared);
• For global warming potential, heating of influent (for cold climate) and methane
emissions from permeate are the most impactful stages;
• For global warming potential, displaced potable water and recovery of methane from
headspace are the most beneficial life cycle stages. Recovery of methane in permeate
(to avoid emissions from permeate) is key; and
• Incremental global warming potential benefits are seen for inclusion of insulation on
surface of the reactor and recovery of methane for CHP rather than just for electricity.
5-8
-------
5.0—Sensitivity Analyses
C3
(D
$•
O
^ Up A?. k£ X? ' "• " "¦ "
<$" ($•
. # .<# ,P # «r
^-i,^,ooo>^ ^ y > y y v ^
nv
4?
m ^
4^ .J? .4^ £?-
& -S*)00, Of# <£ .4^
cr cr
¦ Collection System and Primary Treatment
l Heating of Influent
¦ Heat Loss Control
¦ Recovery of Methane from Headspace
¦ MBR Operation (Electrical Demand, Chemicals, Infrastructure)
¦ Chlorination
¦ Recovery of Methane from Permeate
¦ Methane Emissions from Permeate
¦ Recycled Water Delivery
I Displaced Potable Water
• Net Total
Figure 5-2. Detailed Global Warming Potential Results for AnMBR Climate and Methane Recovery Scenarios
5-9
-------
5.0—Sensitivity Analyses
5.1.3 Cost Results for Climate and Methane Recovery Scenarios
Figure 5-3 displays the detailed cost results for the AnMBR climate and methane
recovery scenarios. Scenarios are ordered by highest to lowest net cost. Overall, the sensitivity
analyses found very little variation between the different scenarios. This is mainly due to the fact
that changes associated with the chosen scenarios mostly impact net energy use and do not affect
O&M labor costs, 55-60% of total cost, or the key contributors to capital costs, 35-40% of total
expenses, such as the anaerobic reactor and MBR infrastructure and installation.6 In all cases, the
AnMBR and recycled water delivery systems are more expensive to construct and operate in
Cincinnati's winter climate than in Miami. The largest difference is the cost of natural gas
needed to heat the influent wastewater and reactor in Cincinnati while no heating is necessary for
the Miami scenarios. Because of the high cost of heating wastewater during Cincinnati winters,
inclusion of insulation has the greatest effect on differences in cost for the Cincinnati scenarios.
All Cincinnati scenarios with insulation are less expensive than any of the scenarios without
insulation. Including dissolved methane recovery from permeate reduces costs as long as the
methane is used to generate electricity, regardless of whether heat recovery is included. CHP is
the most cost effective use of biogas as it captures the value of the electricity and heat produces,
while scenarios with biogas flaring are costlier than either CHP or electricity generation only.
The highest cost scenario is Cincinnati in the winter with no insulation, biogas flaring, and
dissolved methane recovery from the permeate. The lowest cost scenario is the system in Miami
with a CHP and dissolved methane recovery from the permeate.
6 Percent contribution ranges for O&M and amortized capital cost are provided for total costs, not including avoided
DWT costs.
5-10
-------
5.0—Sensitivity Analyses
3,500,000
3,000,000
2,500,000
% 2,000,000
01
^ 1,500,000
1,000,000
500,000
0 —1_ _ _
4^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ Ae^ ^ ^ ^ 4^
-500,000#° <*P cP cP cP o° -o _o _o j& ^ .0 -o _o _o _o
& j? J* J* j?
& & & & & & & & & & & <*? <*? & & & & &
& c&
jf sf X jf jr J? J? J? J? ,* X? o°X ,6^ " ^ -o^ M ^ ^ ^
,^° ,Q# ^ ^ ^ ,0# ^ ^ ^ ^ ,^° .X . J* A . ^ ^
- ^ .# J- J* A •# ^ v/
~./ ^ ^ df ^// ^ ^ ^ ^
&
&
¦ Amortized Capital Cost
¦ O&M Costs
¦ Energy Cost
¦ Avoided DWT Cost
~Net Total
Figure 5-3. Detailed Cost Results for AnMBR Climate and Methane Recovery Scenarios
5-11
-------
5.0—Sensitivity Analyses
5.2 Electrical Grid Mix
Electricity plays a large role in the operational requirements of the MBR systems as well
as the displaced drinking water. In the baseline LCA model, we assume the average U.S.
electrical grid mix. Here, we examine scenarios with different fuel grid mixes representative of
eGRID sub regions in Cincinnati, Ohio and Miami, Florida. Table 5-2 provides more information
on the fuel mix for all electrical grids considered.
Table 5-2. eGRID 2012 Resource Mix by Subregion
Average U.S.
RFCW1
FRCC2
Coal
37.4%
58.7%
19.4%
Oil
0.7%
0.5%
0.6%
Natural Gas
30.3%
11.1%
68.1%
Nuclear
19.0%
25.7%
8.5%
Hydro
6.7%
0.7%
0.1%
Biomass
1.4%
0.5%
1.8%
Wind
3.4%
2.1%
0.0%
Solar
0.1%
0.0%
0.1%
Geothermal
0.4%
0.0%
0.0%
Other
0.5%
0.7%
1.5%
Total
100%
100%
100%
'RFCW = Reliability First Corporation/west eGRID sub
region. Applicable for Cincinnati, OH.
2FRCC = Florida Reliability Coordinating Council eGRID
sub region. Applicable for Miami, FL.
Table 5-3 displays the global warming potential results of this sensitivity analysis for the
multi family land use type. Baseline scenarios include the change from applying both the RFCW
electrical grid and the FRCC electrical grid. Results are shown for the climate scenarios. Only
the applicable regional electrical grids are applied to these scenarios (i.e., sensitivity analysis run
with RFCW electrical grid for Cincinnati, OH scenarios and sensitivity analysis run with FRCC
electrical grid for Miami, FL scenarios). Figure 5-4 displays these results for the baseline
scenarios only.
In all cases, application of the RFCW electrical grid increases global warming potential
impacts, and application of the FRCC electrical grid decreases global warming potential impacts.
This is largely driven by the higher reliance of coal resources in the RFCW electrical grid
compared to the U.S. average electrical grid and the lower reliance on coal in the FRCC
electrical grid compared to the U.S. average electrical grid.
5-12
-------
5.0—Sensitivity Analyses
Table 5-3. Global Warming Potential Results for Electrical Grid Sensitivity Analysis
(kg C02 eq per Year)
GWP(kgCO:
eq/Yr.)
RFCW
%
FRCC2 %
U.S. Ave
RFCW1
Change
FRCC-
Change
1 MGD AeMBR; multi
family
-520,472
-444,985
15%
-748,959
-44%
Baseline
1 MGD AnMBR @35
degrees; multi family
418,691
548,800
31%
-137,990
-133%
1 MGD AnMBR 20
degrees; multi family
-566,116
-441,546
22%
-1,106,250
-95%
CN winter no insulation;
biogas flare; no permeate
methane recovery
756,043
878,624
16%
CN winter w/ insulation;
biogas flare; no permeate
methane recovery
442,878
565,459
28%
CN winter no insulation;
elect; no permeate
methane recovery
427,500
594,437
39%
CN winter w/ insulation;
elect; no permeate
methane recovery
114,335
281,272
146%
CN winter no insulation;
CHP; no permeate
methane recovery
349,576
516,513
48%
CN winter no insulation;
Climate
biogas flare; permeate
methane recovery
342,877
464,670
36%
Sensitivity
(All 1 MGD
AnMBR
CN winter w/ insulation;
CHP; no permeate
methane recovery
36,411
203,348
458%
ambient;
CN winter w/ insulation;
multi
family)
biogas flare; permeate
methane recovery
29,712
151,505
410%
CN winter no insulation;
elect; permeate methane
recovery
-40,822
132,460
424%
CN winter w/ insulation;
elect; permeate methane
recovery
-353,987
-180,705
49%
CN winter no insulation;
CHP; permeate methane
recovery
-131,789
41,494
131%
CN winter w/ insulation;
CHP; permeate methane
recovery
-444,954
-271,671
39%
MIA; biogas flare; no
permeate methane
recovery
-333,883
-699,318
-109%
MIA; elect; no permeate
methane recovery
-679,833
-1,184,630
-74%
5-13
-------
5.0—Sensitivity Analyses
Table 5-3. Global Warming Potential Results for Electrical Grid Sensitivity Analysis
(kg C02 eq per Year)
GWP (kg CO: eq/Yr.)
RFCW1
%
FRCC2 %
U.S. Ave
RFCW1
Change
FRCC2
Change
MIA; biogas flare;
permeate methane
recovery
-702,293
-1,065,180
-52%
MIA; CHP; no permeate
methane recovery
-761,886
-1,266,690
-66%
MIA; elect; permeate
methane recovery
-1,097,521
-1,619,830
-48%
MIA; CHP; permeate
methane recovery
-1,191,226
-1,713,530
-44%
'RFCW = Reliability First Corporation/west eGRID sub region.
2FRCC = Florida Reliability Coordinating Council eGRID sub region.
1 MGD AnMBR @35 degrees; 1 MGD AnMBR (a). 20 degrees;
1 MGD AeMBR; multi-family multi-family multi-family
0.60
1 0.40
| 0,0
{"
Or' -0.60
-0.80
-1.00
Electrical Grid Mix
¦ U.S.Ave "RFCW bFRCC
Figure 5-4. Global Warming Potential Results for Electrical Grid Sensitivity Analysis (kg
CO2 eq per m3 Wastewater Treated)
5.3 Displaced Drinking Water
Based on a literature review of studies reporting energy consumption for drinking water
treatment and distribution, it was determined the energy consumption for the displaced drinking
water considered in the baseline results is relatively high. Table 5-4 lists reported literature
values (in kWh per cubic meter of drinking water delivered) for raw water pumping/treatment at
5-14
-------
5.0—Sensitivity Analyses
plant and finished water pumping, with the baseline value used in this study from the Cashman et
al. (2014) study. While the baseline kWh for treatment is within the range of reported literature
values, the baseline kWh for finished water pumping is considered high compared to other
reported values. This is likely because of the large scale and hilly terrain of the Cincinnati
distribution network. Ranges for electricity consumption by drinking water treatment stage are
shown visually in Figure 5-5.
Table 5-4. Literature Values for Electricity Consumption for
Drinking Water Production and Delivery
Source
kftli in' Drill kinx ft tiler Delivered
R;n\ Wiilcr
Pumping. Surliice
Pliinl/Tiviilmcnl
l-'inishcri
W;i(er
Pumping
l oliil Drinking
W iilcr 1 iviilmenl
iiml Suppl>
Cincinnati Study (Cashman et al., 2014a)
EPRI, 1996
U.S. EPA, 2008
Energy Center of Wisconsin, 2003
WaterRF, 2007
U.S. Geological Survey, 2005
Iowa Association of Municipal Utilities, 2002
EPRIAVERF 2013
deMonsabert et al., 2008
Maas, 2009
deMonsabert and Liner, 1998
Amores etal., 2013
Lassaux et al., 2007
Burton 1996 (from Arpke and Hutzler 2006)
Jeong et al., 2015
Lundie et al., 2004
0.27
0.52
0.79
0.055
0.31
0.37
0.40
N/A
N/A
0.50
N/A
N/A
0.39
0.070
0.50
0.213
0.30
0.51
0.63
0.10
0.73
N/A
N/A
0.42
0.37
0.26
0.63
0.41
0.17
0.58
N/A
N/A
0.11-0.44
0.55
0.29
0.85
0.21
0.18
0.39
0.37
N/A
N/A
N/A
N/A
0.62
0.086
0.28
0.37
5-15
-------
5.0—Sensitivity Analyses
0.9
0.8
-------
5.0—Sensitivity Analyses
1.20
1.00
Cincinnati Study Displaced Drinking Water
Median Electricity Displaced Drinking Water
Min Electricity Displaced Drinking Water
Max Electricity Displaced Drinking Water
f S S f f y s *
&
& ~ ~ ~ y
_rgr jXr jgr jXr -Xr -er jxr
& jP
J? jf
,
K
*y
J? jS
N iH JH b
v v"
* ~ / &
£
/
N?
Z>
y
SI
$
&
*»- * & 4>" & / ^ Sf ^ ^ &
^ ^ & & zf ex cr <$? . 0- .Dv ,Qv y & c ^ >•
> > ,^° ** ^ y y ^ /s ^ # x# *r ^ ^ ^
¦# .¦# -^r >r .¦<$> $r , ,<>° >N ^
y
JSP
\v V
8(V
A?
.y ^ y* y ($•
r y y
y
.A* .<# & & & &
J? ^
& &-1:
&
&
00
*
Figure 5-6. Global Warming Potential Results for Displaced Drinking Water Treatment Sensitivity Analysis for all Considered
Scenarios
5-17
-------
6.0—Conclusions and Next Steps
6.0 Conclusions and Next Steps
This report investigated the baseline LCA and cost analysis results for 18 population
density and scale scenarios for MBRs. Both AeMBRs and AnMBRs were explored.
Additionally, the study examined the operation of AnMBR WWT at 35°C, representative of a
mesophilic AnMBR system, and at 20°C, representative of a psychrophilic AnMBR system. The
results focused on the energy demand and associated greenhouse gases for the scenarios
examined. However, a full suite of life cycle impact assessment results was calculated. Net
energy benefits, considering the displaced drinking water by the delivered recycled water, started
at the 1 MGD scale for the AeMBR and at the 5 MGD scale for the AnMBR operated at 35°C.
For all scales investigated, the AnMBR reactor operated at 20°C resulted in the most net energy
benefits compared to the other investigated systems. This study supports the findings that
AnMBRs operated at lower reactor temperatures represent a promising technology for
decreasing the environmental impacts of wastewater treatment systems. Potential energy demand
and global warming potential benefits of the psychrophilic AnMBR increase when operating in
warm climates and when the dissolved methane in the permeate is recovered. When examining
the energy demand results normalized to a cubic meter of water treated, all energy demand
impacts decrease as the scale increases. While the AnMBR operating at ambient temperature
resulted in notable energy and GHG benefits, the AnMBR costs remained higher than the
AeMBR under all scenarios. The driver for this was the increased operation and maintenance
costs associated with the greater labor infrastructure needs of maintaining the anaerobic reactor
relative to the AeMBR. The study found that all impacts decrease comparatively as the
population density increases, with the highest burdens realized for the semi-rural single family
land use and the lowest overall burdens seen for the high-density urban land use. While this
study focused primarily on energy demand and GHG impacts of the decentralized MBR systems,
there is a potential significant water savings from using recycled wastewater. This study found
that use of recycled water from all decentralized MBR scenarios avoids 0.94 to 0.96 cubic meters
of fresh water per cubic meter of wastewater treated by MBR.
The study found that overall energy demand and GHG impacts were sensitive to the
assumptions regarding displaced potable water. Since displaced potable water represented a
significant net energy and GHG benefit of recycled water production, case specific scenarios
may need to be run to understand the relative savings of displacing regional potable water
produced at centralized drinking water treatment facilities. This research built a framework
model for examining the impact of scale and population density for transitional decentralized
MBR wastewater treatment systems. The AnMBR model was investigated under two reactor
temperatures. The differential in temperature between the influent and the reactor temperature
was shown to play a large role in determining the overall energy and GHG burdens of the
system. The climate scenarios investigated for the psychrophilic AnMBR provide further insight
into combinations of parameters leading to more optimal results. The optimal scenario
investigated from an energy and GHG perspective overall was the psychrophilic AnMBR
operated in warm climate (e.g., Miami, FL) with methane recovery via CHP and both headspace
and permeate methane recovery.
Overall, the LCA model and cost analysis built here can serve as the basis for future
assessments of decentralized water-related technologies. While AeMBRs are largely
commercialized at the scales investigated, the data behind the AnMBR model is based on bench-
6-1
-------
6.0—Conclusions and Next Steps
scale and pilot scale systems. As AnMBRs become more commercial, and operational data is
better understood, the LCA model presented in this work can be continually improved upon.
6-2
-------
7.0—References
7.0 References
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Decomposition of Agricultural Materials Project: Excel Biogas Calculator.
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America's Water Infrastructure Challenge.
3. Amores, M. J., Meneses, M., Pasqualino, J., Anton, A., Castells, F. 2013.
Environmental assessment of urban water cycle on Mediterranean conditions by
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4. Arpke, A., Hutzler, N. 2006. Domestic water use in the United States: a life cycle
approach. Journal of Industrial Ecology, 10, (1-2), 169-184.
5. Baek, S.H., Pagilla K.R., and Kim H.J. 2010. Lab-scale Study of an Anaerobic
Membrane Bioreactor (AnMBR) for Dilute Municipal Wastewater Treatment.
Biotechnology andBioprocess Engineering, 15: 704-708.
6. Bailey, M. P. 1986. Chemical Engineering Plant Cost Index (CEPCI). Chemical
Engineering.
7. Bailey, M. P. 2015. Chemical Engineering Plant Cost Index (CEPCI). Chemical
Engineering.
8. Bandara, W.M.K.R.T.W., Satoh, H., Sasakawa, M., Nakahara, Y., Takahashi, M.,
Okabe, S. 2011. Removal of residual dissolved methane gas in an upflow
anaerobic sludge blanket reactor treating low-strength wastewater at low
temperature with degassing membrane. Water Res. 45, 3533-3540.
9. Bare, J.C., Norris, G.A., Pennington, D.W., McKone, T. 2002. TRACI: The tool
for the reduction and assessment of chemical and other environmental impacts.
Journal of Industrial Ecology, 6, 49-78.
10. Berube, P. R., Hall, E. R., Sutton, P. M. 2006. Parameters Governing Permeate
Flux in an Anaerobic Membrane Bioreactor Treating Low-Strength Municipal
Wastewaters: A Literature Review. Water Environment Research, 78(8): 887-896.
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7-9
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AppendixA-DetailedEnergy and GWP Baseline Results
Appendix A
Detailed Energy and GWP Baseline Results
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Appendix A - Detailed Energy and GWP Baseline Results
Detailed Energy Demand Baseline Results
Detailed cumulative energy demand results for all AeMBR scenarios on an annual basis
are presented in Table A-l through Table A-5. These tables show the relative break out of
impacts for infrastructure, energy for operation, and chemical consumption. Similar annual
energy demand results for AnMBR baseline scenarios (mesophilic and psychrophilic) are
provided in Table A-6 through Table A-15.
Table A-l. Detailed Energy Results for 0.05 MGD AeMBR (MJ/Year)
Water treated per year (m !)
69.130
69.130
69.130
69.130
0.05 MGD
AeMBR [semi
rural single
family]
0.05 MGD
AeMBR
[single
family]
0.05 MGD
AeMBR
[multi family]
0.05 MGD
AeMBR
[high density
urban]
Pipe infrastructure
1,725
943
230
108
Wastewater collection
Pipe installation
339
166
45.2
21.1
Operation
5,998
5,998
5,998
5,998
Preliminary
treatment
Operation
43,819
43,819
43,819
43,819
Pre
Infrastructure
0.030
0.030
0.030
0.030
Treatment
Fine screening
Operation
1,095
1,095
1,095
1,095
Infrastructure
0.13
0.13
0.13
0.13
Plug flow
activated
Aeration,
AeMBR
Operation
603,739
603,739
603,739
603,739
Infrastructure
4,090
4,090
4,090
4,090
sludge with
MBR
Sludge recycle
pumping
Operation
55,322
55,322
55,322
55,322
Infrastructure
6.65
6.65
6.65
6.65
Scouring
Operation
73,726
73,726
73,726
73,726
Sodium hypochlorite, 15%
5,723
5,723
5,723
5,723
MBR
Permeate
Operation
17,199
17,199
17,199
17,199
operation
pumping
Infrastructure
6.45
6.45
6.45
6.45
Waste sludge
Operation
434
434
434
434
pumping
Infrastructure
6.45
6.45
6.45
6.45
MBR
Infrastructure
11,101
11,101
11,101
11,101
Post
treatment
Operation
500,775
500,775
500,775
500,775
Chlorination
Sodium hypochlorite, 15%
32,889
32,889
32,889
32,889
Infrastructure
1,312
1,312
1,312
1,312
Operation
50,774
28,972
13,803
10,773
Recycled water delivery
Pipe infrastructure
5,751
2,820
769
360
Pipe installation
85.1
41.7
11.4
5.40
Displaced drinking water
-842,037
-842,037
-842,037
-842,037
Net Impact
573,879
548,146
530,063
526,472
A-l
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-2. Detailed Energy Results for 0.1 MGD AeMBR (MJ/Year)
Water treated per year (m3)
I3H.251) l?$.2?l> I3H.25V !?H,25()
0.1 MGD
AeMBR [semi
rural single
family]
0.1 MGD
AeMBR
[single
family]
0.1 MGD
AeMBR
[multi
family]
0.1 MGD
AeMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
3,279
1,687
460
206
Pipe installation
678
332
90.5
63.3
Operation
11,996
11,996
11,996
11,996
Pre Treatment
Preliminary
treatment
Operation
60,361
60,361
60,361
60,361
Infrastructure
0.059
0.059
0.059
0.059
Fine screening
Operation
2,191
2,191
2,191
2,191
Infrastructure
0.26
0.26
0.26
0.26
Plug flow
activated
sludge with
MBR
Aeration,
AeMBR
Operation
759,164
759,164
759,164
759,164
Infrastructure
4,090
4,090
4,090
4,090
Sludge recycle
pumping
Operation
110,643
110,643
110,643
110,643
Infrastructure
6.81
6.81
6.81
6.81
MBR operation
Scouring
Operation
147,889
147,889
147,889
147,889
Sodium hypochlorite, 15%
11,145
11,145
11,145
11,145
Permeate
pumping
Operation
34,390
34,390
34,390
34,390
Infrastructure
6.49
6.49
6.49
6.49
Waste sludge
pumping
Operation
865
865
865
865
Infrastructure
6.45
6.45
6.45
6.45
MBR
Infrastructure
20,801
20,801
20,801
20,801
Post treatment
Chlorination
Operation
574,884
574,884
574,884
574,884
Sodium hypochlorite, 15%
65,789
65,789
65,789
65,789
Infrastructure
1,329
1,329
1,329
1,329
Recycled water delivery
Operation
93,417
49,823
19,497
13,427
Pipe infrastructure
11,523
5,631
1,533
716
Pipe installation
171
83.2
22.7
10.5
Displaced drinking water
-1,684,070
-1,684,070
-1,684,070
-1,684,070
Net Impact
230,555
179,043
143,090
135,909
A-2
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-3. Detailed Energy Results for 1 MGD AeMBR (MJ/Year)
Water treated per year (m3)
1.582.59/ 1.382.5')! 1.5S2.5')! 1.582.59/
1 MGD
AeMBR [semi
rural single
family]
1 MGD
AeMBR
[single
family]
1 MGD
AeMBR
[multi
family]
1 MGD
AeMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
34,504
16,869
4,601
2,147
Pipe installation
6,785
3,317
905
485
Operation
119,955
119,955
119,955
119,955
Pre Treatment
Preliminary
treatment
Operation
175,276
175,276
175,276
175,276
Infrastructure
0.59
0.59
0.59
0.59
Fine screening
Operation
22,676
22,676
22,676
22,676
Infrastructure
2.63
2.63
2.63
2.63
Plug flow
activated
sludge with
MBR
Aeration,
AeMBR
Operation
3,034,470
3,034,470
3,034,470
3,034,470
Infrastructure
5,537
5,537
5,537
5,537
Sludge recycle
pumping
Operation
1,095,480
1,095,480
1,095,480
1,095,480
Infrastructure
10.3
10.3
10.3
10.3
MBR operation
Scouring
Operation
1,478,890
1,478,890
1,478,890
1,478,890
Sodium hypochlorite, 15%
109,359
109,359
109,359
109,359
Permeate
pumping
Operation
341,788
341,788
341,788
341,788
Infrastructure
6.77
6.77
6.77
6.77
Waste sludge
pumping
Operation
8,610
8,610
8,610
8,610
Infrastructure
6.45
6.45
6.45
6.45
MBR
Infrastructure
192,694
192,694
192,694
192,694
Post treatment
Chlorination
Operation
909,245
909,245
909,245
909,245
Sodium hypochlorite, 15%
1,568,860
1,568,860
1,568,860
1,568,860
Infrastructure
1,719
1,719
1,719
1,719
Recycled water delivery
Operation
861,124
498,231
121,853
61,200
Pipe infrastructure
115,305
56,414
15,196
7,172
Pipe installation
1,706
832
227
107
Displaced drinking water
-16,840,700
-16,840,700
-16,840,700
-16,840,700
Net Impact
-6,756,690
-7,200,452
-7,633,332
-7,705,003
A-3
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-4. Detailed Energy Results for 5 MGD AeMBR (MJ/Year)
Water treated per year (m3)
6 .V 12.954 6.912.054 6.912.954
5 MGD AeMBR
[single family]
5 MGD AeMBR
[multi family]
5 MGD AeMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
70,901
23,003
10,735
Pipe installation
16,585
4,523
2,596
Operation
599,775
599,775
599,775
Pre Treatment
Preliminary
treatment
Operation
369,175
369,175
369,175
Infrastructure
2.98
2.98
2.98
Fine screening
Operation
113,491
113,491
113,491
Infrastructure
13.1
13.1
13.1
Plug flow
activated
sludge with
MBR
Aeration, AeMBR
Operation
15,227,100
15,227,100
15,227,100
Infrastructure
36,334
36,334
36,334
Sludge recycle
pumping
Operation
5,466,420
5,466,420
5,466,420
Infrastructure
25.5
25.5
25.5
MBR operation
Scouring
Operation
6,550,940
6,550,940
6,550,940
Sodium hypochlorite, 15%
486,542
486,542
486,542
Permeate pumping
Operation
1,708,940
1,708,940
1,708,940
Infrastructure
7.58
7.58
7.58
Waste sludge
pumping
Operation
42,833
42,833
42,833
Infrastructure
6.53
6.53
6.53
MBR
Infrastructure
859,360
859,360
859,360
Post treatment
Chlorination
Operation
1,252,700
1,252,700
1,252,700
Sodium hypochlorite, 15%
3,289,350
3,289,350
3,289,350
Infrastructure
3,419
3,419
3,419
Recycled water delivery
Operation
2,093,230
576,786
273,497
Pipe infrastructure
281,726
76,865
35,861
Pipe installation
4,165
1,135
530
Displaced drinking water
-84,203,700
-84,203,700
-84,203,700
Net Impact
-45,730,658
-47,514,952
-47,874,045
A-4
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-5. Detailed Energy Results for 10 MGD AeMBR (MJ/Year)
Water treated per year (m3)
I3.S25.90 I5.S25.90 I5.S25.00
10 MGD AeMBR
[single family]
10 MGD
AeMBR
[multi family]
10 MGD
AeMBR [high
density urban]
Wastewater collection
Pipe infrastructure
168,686
44,761
21,469
Pipe installation
33,170
13,569
6,818
Operation
1,199,550
1,199,550
1,199,550
Pre Treatment
Preliminary
treatment
Operation
509,396
509,396
509,396
Infrastructure
5.94
5.94
5.94
Fine screening
Operation
226,983
226,983
226,983
Infrastructure
26.3
26.3
26.3
Plug flow activated
sludge with MBR
Aeration, AeMBR
Operation
28,811,000
28,811,000
28,811,000
Infrastructure
46,094
46,094
46,094
Sludge recycle
pumping
Operation
10,921,900
10,921,900
10,921,900
Infrastructure
44.8
44.8
44.8
MBR operation
Scouring
Operation
13,145,700
13,145,700
13,145,700
Sodium hypochlorite, 15%
970,878
970,878
970,878
Permeate pumping
Operation
3,406,930
3,406,930
3,406,930
Infrastructure
8.75
8.75
8.75
Waste sludge
pumping
Operation
85,557
85,557
85,557
Infrastructure
6.61
6.61
6.61
MBR
Infrastructure
1,705,070
1,705,070
1,705,070
Post treatment
Chlorination
Operation
1,435,070
1,435,070
1,435,070
Sodium hypochlorite, 15%
6,578,710
6,578,710
6,578,710
Infrastructure
5,543
5,543
5,543
Recycled water delivery
Operation
4,178,340
1,145,450
538,875
Pipe infrastructure
563,936
153,616
71,723
Pipe installation
8,317
2,272
1,059
Displaced drinking water
-168,407,000
-168,407,000
-168,407,000
Net Impact
-94,406,078
-97,998,858
-98,718,583
A-5
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-6. Detailed Energy Results for 0.05 MGD AnMBR, 35°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
69. ISO
69. ISO
69. ISO
69. ISO
0.05 MGD
AnMBR
[semi rural
single
family]
0.05 MGD
AnMBR
[single family]
0.05 MGD
AnMBR
[multi family]
0.05 MGD
AnMBR
[high density
urban]
Pipe infrastructure
1,725
943
230
108
Wastewater collection
Pipe installation
339
166
45.2
21.1
Operation
5,998
5,998
5,998
5,998
Preliminary
treatment
Operation
43,819
43,819
43,819
43,819
Pre Treatment
Infrastructure
0.030
0.030
0.030
0.030
Fine
Operation
1,095
1,095
1,095
1,095
screening
Infrastructure
0.13
0.13
0.13
0.13
Heating of influent
4,416,950
4,416,950
4,416,950
4,416,950
MBR pump
11,221
11,221
11,221
11,221
Heat loss control
13,476
13,476
13,476
13,476
MBR operation
Recovery of methane
-279,690
-279,690
-279,690
-279,690
Effluent pumping out
38,089
38,089
38,089
38,089
Heat recovery from discharge water
-3,478,530
-3,478,530
-3,478,530
-3,478,530
Biogas recirculation pump
1,748
1,748
1,748
1,748
Sodium hypochlorite, 15%
19,701
19,701
19,701
19,701
MBR
Infrastructure
26,758
26,758
26,758
26,758
Post
treatment
Operation
500,775
500,775
500,775
500,775
Chlorination
Sodium hypochlorite, 15%
32,889
32,889
32,889
32,889
Infrastructure
1,312
1,312
1,312
1,312
Operation
50,774
28,972
13,803
10,773
Recycled water delivery
Pipe infrastructure
5,751
2,820
769
360
Pipe installation
85.1
41.7
11.4
5.40
Displaced drinking water
-851,088
-851,088
-851,088
-851,088
Net Impact
563,197
537,464
519,380
515,790
A-6
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-7. Detailed Energy Results for 0.1 MGD AnMBR, 35°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
158.25') 158.25') 158.25') 158.25')
0.1 MGD
AnMBR
[semi rural
single
family]
0.1 MGD
AnMBR
[single family]
0.1 MGD
AnMBR
[multi family]
0.1 MGD
AnMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
3,279
1,687
460
206
Pipe installation
678
332
90.5
63.3
Operation
11,996
11,996
11,996
11,996
Pre Treatment
Preliminary
treatment
Operation
60,361
60,361
60,361
60,361
Infrastructure
0.059
0.059
0.059
0.059
Fine
screening
Operation
2,191
2,191
2,191
2,191
Infrastructure
0.26
0.26
0.26
0.26
MBR operation
Heating of influent
8,833,900
8,833,900
8,833,900
8,833,900
MBR pump
22,441
22,441
22,441
22,441
Heat loss control
19,228
19,228
19,228
19,228
Recovery of methane
-559,379
-559,379
-559,379
-559,379
Effluent pumping out
76,171
76,171
76,171
76,171
Heat recovery from discharge water
-6,957,060
-6,957,060
-6,957,060
-6,957,060
Biogas recirculation pump
3,495
3,495
3,495
3,495
Sodium hypochlorite, 15%
39,413
39,413
39,413
39,413
MBR
Infrastructure
27,497
27,497
27,497
27,497
Post
treatment
Chlorination
Operation
574,884
574,884
574,884
574,884
Sodium hypochlorite, 15%
65,789
65,789
65,789
65,789
Infrastructure
1,329
1,329
1,329
1,329
Recycled water delivery
Operation
93,417
49,823
19,497
13,427
Pipe infrastructure
11,523
5,631
1,533
716
Pipe installation
171
83.2
22.7
10.5
Displaced drinking water
-1,703,660
-1,703,660
-1,703,660
-1,703,660
Net Impact
627,664
576,152
540,199
533,019
A-7
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-8. Detailed Energy Results for 1 MGD AnMBR, 35°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
1.382.5')! 1,3X2.591 1.3X2.5')/
1 MGD AnMBR
[semi rural single
family]
1 MGD AnMBR
[single family]
1 MGD AnMBR
[multi family]
Wastewater collection
Pipe infrastructure
34,504
16,869
4,601
Pipe installation
6,785
3,317
905
Operation
119,955
119,955
119,955
Pre Treatment
Preliminary
treatment
Operation
175,276
175,276
175,276
Infrastructure
0.59
0.59
0.59
Fine screening
Operation
22,676
22,676
22,676
Infrastructure
2.63
2.63
2.63
MBR operation
Heating of influent
88,339,000
88,339,000
88,339,000
MBR pump
224,412
224,412
224,412
Heat loss control
68,568
68,568
68,568
Recovery of methane
-5,593,790
-5,593,790
-5,593,790
Effluent pumping out
761,649
761,649
761,649
Heat recovery from discharge water
-69,570,600
-69,570,600
-69,570,600
Biogas recirculation pump
34,952
34,952
34,952
Sodium hypochlorite, 15%
291,739
291,739
291,739
MBR
Infrastructure
518,521
518,521
518,521
Post treatment
Chlorination
Operation
909,245
909,245
909,245
Sodium hypochlorite, 15%
1,568,860
1,568,860
1,568,860
Infrastructure
1,719
1,719
1,719
Recycled water delivery
Operation
861,124
498,231
121,853
Pipe infrastructure
115,305
56,414
15,196
Pipe installation
1,706
832
227
Displaced drinking water
-17,095,900
-17,095,900
-17,095,900
Net Impact
1,795,710
1,351,948
919,068
A-8
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-9. Detailed Energy Results for 5 MGD AnMBR, 35°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
6. 9 12,954
6.912.954
6.912.954
5 MGD
AnMBR [single
family]
5 MGD AnMBR
[multi family]
5 MGD
AnMBR [high
density urban]
Pipe infrastructure
70,901
23,003
10,735
Wastewater collection
Pipe installation
16,585
4,523
2,596
Operation
599,775
599,775
599,775
Preliminary
treatment
Operation
369,175
369,175
369,175
Pre Treatment
Infrastructure
2.98
2.98
2.98
Fine screening
Operation
113,491
113,491
113,491
Infrastructure
13.1
13.1
13.1
Heating of influent
441,695,000
441,695,000
441,695,000
MBR pump
1,122,060
1,122,060
1,122,060
Heat loss control
233,580
233,580
233,580
MBR operation
Recovery of methane
-27,969,000
-27,969,000
-27,969,000
Effluent pumping out
3,808,220
3,808,220
3,808,220
Heat recovery from discharge water
-347,853,000
-347,853,000
-347,853,000
Biogas recirculation pump
174,760
174,760
174,760
Sodium hypochlorite, 15%
1,215,600
1,215,600
1,215,600
MBR
Infrastructure
2,160,855
2,160,855
2,160,855
Operation
1,252,700
1,252,700
1,252,700
Post treatment
Chlorination
Sodium hypochlorite, 15%
3,289,350
3,289,350
3,289,350
Infrastructure
3,419
3,419
3,419
Operation
2,093,230
576,786
273,497
Recycled water delivery
Pipe infrastructure
281,726
76,865
35,861
Pipe installation
4,165
1,135
530
Displaced drinking water
-85,565,700
-85,565,700
-85,565,700
Net Impact
-2,883,092
-4,667,387
-5,026,480
A-9
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-10. Detailed Energy Results for 10 MGD AnMBR, 35°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
l?.S25.')0
I5.825.l)<)
1?.S25,')D
10 MGD
AnMBR
[single
family]
10 MGD AnMBR
[multi family]
10 MGD
AnMBR [high
density urban]
Pipe infrastructure
168,686
44,761
21,469
Wastewater collection
Pipe installation
33,170
13,569
6,818
Operation
1,199,550
1,199,550
1,199,550
Preliminary
treatment
Operation
509,396
509,396
509,396
Pre Treatment
Infrastructure
5.94
5.94
5.94
Fine screening
Operation
226,983
226,983
226,983
Infrastructure
26.3
26.3
26.3
Heating of influent
883,390,000
883,390,000
883,390,000
MBR pump
2,244,120
2,244,120
2,244,120
Heat loss control
399,243
399,243
399,243
MBR operation
Recovery of methane
-55,937,900
-55,937,900
-55,937,900
Effluent pumping out
7,616,430
7,616,430
7,616,430
Heat recovery from discharge water
-695,706,000
-695,706,000
-695,706,000
Biogas recirculation pump
349,522
349,522
349,522
Sodium hypochlorite, 15%
2,188,000
2,188,000
2,188,000
MBR
Infrastructure
3,888,905
3,888,905
3,888,905
Operation
1,435,070
1,435,070
1,435,070
Post treatment
Chlorination
Sodium hypochlorite, 15%
6,578,710
6,578,710
6,578,710
Infrastructure
5,543
5,543
5,543
Operation
4,178,340
1,145,450
538,875
Recycled water delivery
Pipe infrastructure
563,936
153,616
71,723
Pipe installation
8,317
2,272
1,059
Displaced drinking water
-171,080,000
-171,080,000
-171,080,000
Net Impact
-7,739,946
-11,332,727
-12,052,451
A-10
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-ll. Detailed Energy Results for 0.05 MGD AnMBR, 20°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
69. ISO 69,!?() 69,!?() 69,!?()
0.05 MGD
AnMBR
[semi rural
single
family]
0.05 MGD
AnMBR [single
family]
0.05 MGD
AnMBR
[multi family]
0.05 MGD
AnMBR
[high
density
urban]
Wastewater collection
Pipe infrastructure
1,725
943
230
108
Pipe installation
339
166
45.2
21.1
Operation
5,998
5,998
5,998
5,998
Pre Treatment
Preliminary
treatment
Operation
43,819
43,819
43,819
43,819
Infrastructure
0.030
0.030
0.030
0.030
Fine
screening
Operation
1,095
1,095
1,095
1,095
Infrastructure
0.13
0.13
0.13
0.13
MBR operation
Heating of influent
0
0
0
0
MBR pump
11,221
11,221
11,221
11,221
Heat loss control
0
0
0
0
Recovery of methane
-251,125
-251,125
-251,125
-251,125
Effluent pumping out
38,089
38,089
38,089
38,089
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
1,748
1,748
1,748
1,748
Sodium hypochlorite, 15%
19,701
19,701
19,701
19,701
MBR
Infrastructure
26,758
26,758
26,758
26,758
Post
treatment
Chlorination
Operation
500,775
500,775
500,775
500,775
Sodium hypochlorite, 15%
32,889
32,889
32,889
32,889
Infrastructure
1,312
1,312
1,312
1,312
Recycled water delivery
Operation
50,774
28,972
13,803
10,773
Pipe infrastructure
5,751
2,820
769
360
Pipe installation
85.1
41.7
11.4
5.40
Displaced drinking water
-851,088
-851,088
-851,088
-851,088
Net Impact
-360,134
-385,867
-403,951
-407,542
A-ll
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-12. Detailed Energy Results for 0.1 MGD AnMBR, 20°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
158.25V
15 $.2 59
158.25'J
158.259
0.1 MGD
AnMBR
[semi rural
single
family]
0.1 MGD
AnMBR
[single
family]
0.1 MGD
AnMBR
[multi family]
0.1 MGD
AnMBR [high
density urban]
Pipe infrastructure
3,279
1,687
460
206
Wastewater collection
Pipe installation
678
332
90.5
63.3
Operation
11,996
11,996
11,996
11,996
Preliminary
treatment
Operation
60,361
60,361
60,361
60,361
Pre Treatment
Infrastructure
0.059
0.059
0.059
0.059
Fine
Operation
2,191
2,191
2,191
2,191
screening
Infrastructure
0.26
0.26
0.26
0.26
Heating of influent
0
0
0
0
MBR pump
22,441
22,441
22,441
22,441
Heat loss control
0
0
0
0
MBR operation
Recovery of methane
-502,249
-502,249
-502,249
-502,249
Effluent pumping out
76,171
76,171
76,171
76,171
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
3,495
3,495
3,495
3,495
Sodium hypochlorite, 15%
39,413
39,413
39,413
39,413
MBR
Infrastructure
27,497
27,497
27,497
27,497
Post
treatment
Operation
574,884
574,884
574,884
574,884
Chlorination
Sodium hypochlorite, 15%
65,789
65,789
65,789
65,789
Infrastructure
1,329
1,329
1,329
1,329
Operation
93,417
49,823
19,497
13,427
Recycled water delivery
Pipe infrastructure
11,523
5,631
1,533
716
Pipe installation
171
83.2
22.7
10.5
Displaced drinking water
-1,703,660
-1,703,660
-1,703,660
-1,703,660
Net Impact
-1,211,274
-1,262,786
-1,298,739
-1,305,920
A-12
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-13. Detailed Energy Results for 1 MGD AnMBR, 20°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
1.382,591 1.3X2.591 1.382,591 1.382.591
1 MGD
AnMBR [semi
rural single
family]
1 MGD
AnMBR
[single
family]
1 MGD
AnMBR
[multi family]
1 MGD
AnMBR [high
density urban]
Wastewater collection
Pipe infrastructure
34,504
16,869
4,601
2,147
Pipe installation
6,785
3,317
905
485
Operation
119,955
119,955
119,955
119,955
Pre Treatment
Preliminary
treatment
Operation
175,276
175,276
175,276
175,276
Infrastructure
0.59
0.59
0.59
0.59
Fine
screening
Operation
22,676
22,676
22,676
22,676
Infrastructure
2.63
2.63
2.63
2.63
MBR operation
Heating of influent
0
0
0
0
MBR pump
224,412
224,412
224,412
224,412
Heat loss control
0
0
0
0
Recovery of methane
-5,022,490
-5,022,490
-5,022,490
-5,022,490
Effluent pumping out
761,649
761,649
761,649
761,649
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
34,952
34,952
34,952
34,952
Sodium hypochlorite, 15%
291,739
291,739
291,739
291,739
MBR
Infrastructure
518,521
518,521
518,521
518,521
Post
treatment
Chlorination
Operation
909,245
909,245
909,245
909,245
Sodium hypochlorite, 15%
1,568,860
1,568,860
1,568,860
1,568,860
Infrastructure
1,719
1,719
1,719
1,719
Recycled water delivery
Operation
861,124
498,231
121,853
61,200
Pipe infrastructure
115,305
56,414
15,196
7,172
Pipe installation
1,706
832
227
107
Displaced drinking water
-17,095,900
-17,095,900
-17,095,900
-17,095,900
Net Impact
-16,469,959
-16,913,720
-17,346,601
-17,418,271
A-13
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-14. Detailed Energy Results for 5 MGD AnMBR, 20°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
6.012.9?4
6 .VI2.V54
6.9I2.V54
5 MGD AnMBR
[single family]
5 MGD AnMBR
[multi family]
5 MGD AnMBR
[high density urban]
Pipe infrastructure
70,901
23,003
10,735
Wastewater collection
Pipe installation
16,585
4,523
2,596
Operation
599,775
599,775
599,775
Preliminary
treatment
Operation
369,175
369,175
369,175
Pre Treatment
Infrastructure
2.98
2.98
2.98
Fine
Operation
113,491
113,491
113,491
screening
Infrastructure
13.1
13.1
13.1
Heating of influent
0
0
0
MBR pump
1,122,060
1,122,060
1,122,060
Heat loss control
0
0
0
MBR operation
Recovery of methane
-25,112,500
-25,112,500
-25,112,500
Effluent pumping out
3,808,220
3,808,220
3,808,220
Heat recovery from discharge water
0
0
0
Biogas recirculation pump
174,760
174,760
174,760
Sodium hypochlorite, 15%
1,215,600
1,215,600
1,215,600
MBR
Infrastructure
2,160,855
2,160,855
2,160,855
Post
treatment
Operation
1,252,700
1,252,700
1,252,700
Chlorination
Sodium hypochlorite, 15%
3,289,350
3,289,350
3,289,350
Infrastructure
3,419
3,419
3,419
Operation
2,093,230
576,786
273,497
Recycled water delivery
Pipe infrastructure
281,726
76,865
35,861
Pipe installation
4,165
1,135
530
Displaced drinking water
-85,565,700
-85,565,700
-85,565,700
Net Impact
-94,102,172
-95,886,467
-96,245,560
A-14
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-15. Detailed Energy Results for 10 MGD AnMBR, 20°C Reactor Temperature
(MJ/Year)
Water treated per year (m3)
13.S25.90
13.$2.1.00 ¦
13.825.W~
10 MGD AnMBR
[single family]
10 MGD
AnMBR [multi
family]
10 MGD AnMBR
[high density
urban]
Pipe infrastructure
168,686
44,761
21,469
Wastewater collection
Pipe installation
33,170
13,569
6,818
Operation
1,199,550
1,199,550
1,199,550
Preliminary
treatment
Operation
509,396
509,396
509,396
Pre Treatment
Infrastructure
5.94
5.94
5.94
Fine
Operation
226,983
226,983
226,983
screening
Infrastructure
26.3
26.3
26.3
Heating of influent
0
0
0
MBR pump
2,244,120
2,244,120
2,244,120
Heat loss control
0
0
0
MBR operation
Recovery of methane
-50,224,900
-50,224,900
-50,224,900
Effluent pumping out
7,616,430
7,616,430
7,616,430
Heat recovery from discharge water
0
0
0
Biogas recirculation pump
349,522
349,522
349,522
Sodium hypochlorite, 15%
2,188,000
2,188,000
2,188,000
MBR
Infrastructure
3,888,905
3,888,905
3,888,905
Operation
1,435,070
1,435,070
1,435,070
Post treatment
Chlorination
Sodium hypochlorite, 15%
6,578,710
6,578,710
6,578,710
Infrastructure
5,543
5,543
5,543
Operation
4,178,340
1,145,450
538,875
Recycled water delivery
Pipe infrastructure
563,936
153,616
71,723
Pipe installation
8,317
2,272
1,059
Displaced drinking water
-171,080,000
-171,080,000
-171,080,000
Net Impact
-190,110,189
-193,702,970
-194,422,694
Detailed Global Warming Potential Baseline Results
Detailed global warming potential results for all AeMBR scenarios on an annual basis are
presented in Table A-16 through Table A-20. Similar annual global warming potential results for
AnMBR baseline scenarios (mesophilic and psychrophilic) are provided in Table A-21 through
Table A-30.
A-15
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-16. Detailed Global Warming Potential Results for 0.05 MGD AeMBR
(kg C02 eq/Year)
Water treated per year (m3)
69.130
69.130
69.130
69.130
0.05 MGD
0.05 MGD
AeMBR [semi
AeMBR
0.05 MGD
0.05 MGD
rural single
family]
[single
family]
AeMBR [multi
family]
AeMBR [high
density urban]
Pipe infrastructure
229
116
30.5
14.4
Wastewater collection
Pipe installation
22.3
10.9
2.98
1.39
Operation
925
925
925
925
Preliminary
treatment
Operation
2,735
2,735
2,735
2,735
Pre Treatment
Infrastructure
0.0020
0.0020
0.0020
0.0020
Fine
Operation
68.4
68.4
68.4
68.4
screening
Infrastructure
0.0087
0.0087
0.0087
0.0087
Plug flow
activated
Aeration,
AeMBR
Operation
37,679
37,679
37,679
37,679
Infrastructure
748
748
748
748
sludge with
MBR
Sludge
recycle
pumping
Operation
3,453
3,453
3,453
3,453
Infrastructure
0.44
0.44
0.44
0.44
Scouring
Operation
4,601
4,601
4,601
4,601
Sodium hypochlorite, 15%
291
291
291
291
MBR operation
Permeate
Operation
1,073
1,073
1,073
1,073
pumping
Infrastructure
0.42
0.42
0.42
0.42
Waste
sludge
pumping
Operation
27.1
27.1
27.1
27.1
Infrastructure
0.42
0.42
0.42
0.42
MBR
Infrastructure
1,055
1,055
1,055
1,055
Operation
31,253
31,253
31,253
31,253
Post treatment
Chlorination
Sodium hypochlorite, 15%
1,671
1,671
1,671
1,671
Infrastructure
242
242
242
242
Operation
3,151
1,798
857
669
Recycled water delivery
Pipe infrastructure
301
148
40.2
18.8
Pipe installation
5.60
2.75
0.75
0.36
Displaced drinking water
-52,299
-52,299
-52,299
-52,299
Net Impact
37,230
35,597
34,453
34,225
A-16
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-17. Detailed Global Warming Potential Results for 0.1 MGD AeMBR
(kg C02 eq/Year)
Water treated per year (m3)
1 38.259
138.259
138.259
138.259
0.1 MGD
AeMBR [semi
rural single
family]
0.1 MGD
AeMBR
[single
family]
0.1 MGD
AeMBR [multi
family]
0.1 MGD
AeMBR [high
density urban]
Pipe infrastructure
427
223
61.0
27.9
Wastewater collection
Pipe installation
44.7
21.8
5.96
4.17
Operation
1,849
1,849
1,849
1,849
Preliminary
treatment
Operation
3,767
3,767
3,767
3,767
Pre Treatment
Infrastructure
0.0039
0.0039
0.0039
0.0039
Fine
Operation
137
137
137
137
screening
Infrastructure
0.017
0.017
0.017
0.017
Plug flow
activated
Aeration,
AeMBR
Operation
47,379
47,379
47,379
47,379
Infrastructure
748
748
748
748
sludge with
MBR
Sludge
recycle
pumping
Operation
6,905
6,905
6,905
6,905
Infrastructure
0.45
0.45
0.45
0.45
Scouring
Operation
9,230
9,230
9,230
9,230
Sodium hypochlorite, 15%
566
566
566
566
MBR operation
Permeate
Operation
2,147
2,147
2,147
2,147
pumping
Infrastructure
0.43
0.43
0.43
0.43
Waste
sludge
pumping
Operation
54.0
54.0
54.0
54.0
Infrastructure
0.42
0.42
0.42
0.42
MBR
Infrastructure
1,857
1,857
1,857
1,857
Operation
35,878
35,878
35,878
35,878
Post treatment
Chlorination
Sodium hypochlorite, 15%
3,343
3,343
3,343
3,343
Infrastructure
245
245
245
245
Operation
5,797
3,092
1,210
833
Recycled water delivery
Pipe infrastructure
603
294
80.1
37.5
Pipe installation
11.2
5.48
1.50
0.69
Displaced drinking water
-104,599
-104,599
-104,599
-104,599
Net Impact
16,390
13,144
10,865
10,410
A-17
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-18. Detailed Global Warming Potential Results for 1 MGD AeMBR
(kg C02 eq/Year)
Water treated per year (mi)
1.3X2.591 1.3X2.591 1.3X2.591 1.3X2.591
1 MGD AeMBR
[semi rural
single family]
1 MGD
AeMBR
[single family]
1 MGD
AeMBR
[multi
family]
1 MGD
AeMBR [high
density urban]
Wastewater collection
Pipe infrastructure
4,572
2,235
610
2X4
Pipe installation
447
21X
59.6
32.0
Operation
IX,491
IX,491
IX,491
IX,491
Pre Treatment
Preliminary
treatment
Operation
10,939
10,939
10,939
10,939
Infrastructure
0.039
0.039
0.039
0.039
Fine
screening
Operation
1,415
1,415
1,415
1,415
Infrastructure
0.17
0.17
0.17
0.17
Plug flow
activated
sludge with
MBR
Aeration,
AeMBR
Operation
1X9,37X
1X9,37X
1X9,37X
1X9,37X
Infrastructure
1,012
1,012
1,012
1,012
Sludge
recycle
pumping
Operation
6X,367
6X,367
6X,367
6X,367
Infrastructure
0.6X
0.6X
0.6X
0.6X
MBR operation
Scouring
Operation
92,296
92,296
92,296
92,296
Sodium hypochlorite, 15%
5,557
5,557
5,557
5,557
Permeate
pumping
Operation
21,331
21,331
21,331
21,331
Infrastructure
0.45
0.45
0.45
0.45
Waste sludge
pumping
Operation
537
537
537
537
Infrastructure
0.42
0.42
0.42
0.42
MBR
Infrastructure
15,7X0
15,7X0
15,7X0
15,7X0
Post treatment
Chlorination
Operation
56,745
56,745
56,745
56,745
Sodium hypochlorite, 15%
34,330
34,330
34,330
34,330
Infrastructure
316
316
316
316
Recycled water delivery
Operation
53,441
30,920
7,562
3,79X
Pipe infrastructure
6,032
2,952
776
375
Pipe installation
112
54.X
15.0
6.XX
Displaced drinking water
-1,045,990
-1,045,990
-1,045,990
-1,045,990
Net Impact
-464,890
-493,115
-520,472
-524,998
A-18
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-19. Detailed Global Warming Potential Results for 5 MGD AeMBR
(kg C02 eq/Year)
Water treated per year (mS)
6.912.954 6.912.954 6.912.954
5 MGD AeMBR
[single family]
5 MGD AeMBR
[multi family]
5 MGD AeMBR [high
density urban]
Wastewater collection
Pipe infrastructure
9,391
3,048
1,422
Pipe installation
1,092
298
171
Operation
92,454
92,454
92,454
Pre Treatment
Preliminary
treatment
Operation
23,040
23,040
23,040
Infrastructure
0.20
0.20
0.20
Fine screening
Operation
7,083
7,083
7,083
Infrastructure
0.87
0.87
0.87
Plug flow
activated sludge
with MBR
Aeration,
AeMBR
Operation
950,306
950,306
950,306
Infrastructure
6,672
6,672
6,672
Sludge recycle
pumping
Operation
341,153
341,153
341,153
Infrastructure
1.68
1.68
1.68
MBR operation
Scouring
Operation
408,837
408,837
408,837
Sodium hypochlorite, 15%
24,725
24,725
24,725
Permeate
pumping
Operation
106,653
106,653
106,653
Infrastructure
0.50
0.50
0.50
Waste sludge
pumping
Operation
2,673
2,673
2,673
Infrastructure
0.43
0.43
0.43
MBR
Infrastructure
70,430
70,430
70,430
Post treatment
Chlorination
Operation
78,179
78,179
78,179
Sodium hypochlorite, 15%
167,159
167,159
167,159
Infrastructure
627
627
627
Recycled water delivery
Operation
129,905
35,795
16,973
Pipe infrastructure
14,743
4,021
1,876
Pipe installation
274
74.8
34.9
Displaced drinking water
-5,229,940
-5,229,940
-5,229,940
Net Impact
-2,794,540
-2,906,708
-2,929,467
A-19
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-20. Detailed Global Warming Potential Results for 10 MGD AeMBR
(kg C02 eq/Year)
Water treated per year (m3)
13.825.907 13.825.907 13.825.907
10 MGD AeMBR
[single family]
10 MGD
AeMBR [multi
family]
10 MGD AeMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
22,350
5,924
2,845
Pipe installation
2,184
893
449
Operation
184,908
184,908
184,908
Pre Treatment
Preliminary
treatment
Operation
31,791
31,791
31,791
Infrastructure
0.39
0.39
0.39
Fine screening
Operation
14,166
14,166
14,166
Infrastructure
1.73
1.73
1.73
Plug flow activated
sludge with MBR
Aeration,
AeMBR
Operation
1,798,060
1,798,060
1,798,060
Infrastructure
8,457
8,457
8,457
Sludge recycle
pumping
Operation
681,623
681,623
681,623
Infrastructure
2.95
2.95
2.95
MBR operation
Scouring
Operation
820,408
820,408
820,408
Sodium hypochlorite, 15%
49,338
49,338
49,338
Permeate
pumping
Operation
212,622
212,622
212,622
Infrastructure
0.58
0.58
0.58
Waste sludge
pumping
Operation
5,339
5,339
5,339
Infrastructure
0.44
0.44
0.44
MBR
Infrastructure
138,680
138,680
138,680
Post treatment
Chlorination
Operation
89,561
89,561
89,561
Sodium hypochlorite, 15%
334,318
334,318
334,318
Infrastructure
1,016
1,016
1,016
Recycled water delivery
Operation
259,305
71,086
33,442
Pipe infrastructure
29,506
8,037
3,752
Pipe installation
548
150
69.7
Displaced drinking water
-10,459,900
-10,459,900
-10,459,900
Net Impact
-5,775,714
-6,003,517
-6,049,049
A-20
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-21. Detailed Global Warming Potential Results for 0.05 MGD AnMBR, 35°C
Reactor Temperature (kg C02 eq/Year)
Water treated per year (m3)
69.130
69.130
69.130
69.130
0.05 MGD
AnMBR
[semi rural
single
family]
0.05 MGD
AnMBR
[single
family]
0.05 MGD
AnMBR
[multi family]
0.05 MGI)
AnMBR
[high
density
urban]
Pipe infrastructure
229
116
30.5
14.4
Wastewater collection
Pipe installation
22.3
10.9
2.98
1.39
Operation
925
925
925
925
Preliminary
treatment
Operation
2,735
2,735
2,735
2,735
Pre Treatment
Infrastructure
0.0020
0.0020
0.0020
0.0020
Fine
Operation
68.4
68.4
68.4
68.4
screening
Infrastructure
0.0087
0.0087
0.0087
0.0087
Heating of influent
267,455
267,455
267,455
267,455
MBR pump
700
700
700
700
Heat loss control
816
816
816
816
MBR operation
Recovery of methane
-16,021
-16,021
-16,021
-16,021
Effluent pumping out
2,377
2,377
2,377
2,377
Heat recovery from discharge water
-210,632
-210,632
-210,632
-210,632
Biogas recirculation pump
109
109
109
109
Sodium hypochlorite, 15%
1,001
1,001
1,001
1,001
MBR
Infrastructure
3,293
3,293
3,293
3,293
Operation
31,253
31,253
31,253
31,253
Post treatment
Chlorination
Sodium hypochlorite, 15%
1,671
1,671
1,671
1,671
Infrastructure
242
242
242
242
Operation
3,151
1,798
857
669
Pipe infrastructure
301
148
40.2
18.8
Recycled water delivery
Pipe installation
5.60
2.75
0.75
0.36
Displaced drinking water
-52,862
-52,862
-52,862
-52,862
Methane emissions from permeate
20,300
20,300
20,300
20,300
Net Impact
57,138
55,505
54,361
54,134
A-21
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-22. Detailed Global Warming Potential Results for 0.1 MGD AnMBR, 35°C
Reactor Temperature (kg C02 eq/Year)
Water treated per year (m3)
138.259
138.259
138.259
138.259
0.1 MGD
AnMBR
[semi rural
single
family]
0.1 MGD
AnMBR
[single
family]
0.1 MGD
AnMBR
[multi family]
0.1 MGD
AnMBR
[high
density
urban]
Pipe infrastructure
427
223
61.0
27.9
Wastewater collection
Pipe installation
44.7
21.8
5.96
4.17
Operation
1,849
1,849
1,849
1,849
Preliminary
treatment
Operation
3,767
3,767
3,767
3,767
Pre Treatment
Infrastructure
0.0039
0.0039
0.0039
0.0039
Fine
Operation
137
137
137
137
screening
Infrastructure
0.017
0.017
0.017
0.017
Heating of influent
534,910
534,910
534,910
534,910
MBR pump
1,401
1,401
1,401
1,401
Heat loss control
1,164
1,164
1,164
1,164
MBR operation
Recovery of methane
-32,043
-32,043
-32,043
-32,043
Effluent pumping out
4,754
4,754
4,754
4,754
Heat recovery from discharge water
-421,263
-421,263
-421,263
-421,263
Biogas recirculation pump
218
218
218
218
Sodium hypochlorite, 15%
2,003
2,003
2,003
2,003
MBR
Infrastructure
3,475
3,475
3,475
3,475
Operation
35,878
35,878
35,878
35,878
Post treatment
Chlorination
Sodium hypochlorite, 15%
3,343
3,343
3,343
3,343
Infrastructure
245
245
245
245
Operation
5,797
3,092
1,210
833
Pipe infrastructure
603
294
80.1
37.5
Recycled water delivery
Pipe installation
11.2
5.48
1.50
0.69
Displaced drinking water
-105,815
-105,815
-105,815
-105,815
Methane emissions from permeate
40,634
40,634
40,634
40,634
Net Impact
81,541
78,295
76,016
75,561
A-22
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-23. Detailed Global Warming Potential Results for 1 MGD AnMBR, 35°C Reactor
Temperature (kg C02 eq/Year)
Water treated per year (m3)
1.382.591
1.382.591
1.382.591
1.382.591
1 MGD
AnMBR
[semi rural
single
family]
1 MGD
AnMBR
[single
family]
1 MGD
AnMBR
[multi family]
1 MGD
AnMBR
[high
density
urban]
Pipe infrastructure
4,572
2,235
610
284
Wastewater collection
Pipe installation
447
218
59.6
32.0
Operation
18,491
18,491
18,491
18,491
Preliminary
treatment
Operation
10,939
10,939
10,939
10,939
Pre Treatment
Infrastructure
0.039
0.039
0.039
0.039
Fine
Operation
1,415
1,415
1,415
1,415
screening
Infrastructure
0.17
0.17
0.17
0.17
Heating of influent
5,349,100
5,349,100
5,349,100
5,349,100
MBR pump
14,005
14,005
14,005
14,005
Heat loss control
4,152
4,152
4,152
4,152
MBR operation
Recovery of methane
-320,426
-320,426
-320,426
-320,426
Effluent pumping out
47,534
47,534
47,534
47,534
Heat recovery from discharge water
-4,212,630
-4,212,630
-4,212,630
-4,212,630
Biogas recirculation pump
2,181
2,181
2,181
2,181
Sodium hypochlorite, 15%
14,826
14,826
14,826
14,826
MBR
Infrastructure
42,772
42,772
42,772
42,772
Operation
56,745
56,745
56,745
56,745
Post treatment
Chlorination
Sodium hypochlorite, 15%
34,330
34,330
34,330
34,330
Infrastructure
316
316
316
316
Operation
53,441
30,920
7,562
3,798
Pipe infrastructure
6,032
2,952
776
375
Recycled water delivery
Pipe installation
112
54.8
15.0
6.88
Displaced drinking water
-1,061,840
-1,061,840
-1,061,840
-1,061,840
Methane emissions from permeate
407,758
407,758
407,758
407,758
Net Impact
474,272
446,048
418,691
414,165
A-23
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-24. Detailed Global Warming Potential Results for 5 MGD AnMBR, 35°C Reactor
Temperature (kg C02 eq/Year)
Water treated per year (m3)
6.912.954
6.912.954
6.912.954
5 MGD AnMBR
[single family]
5 MGD
AnMBR
[multi family]
5 MGD AnMBR
[high density
urban]
Pipe infrastructure
9,391
3,048
1,422
Wastewater collection
Pipe installation
1,092
298
171
Operation
92,454
92,454
92,454
Preliminary
treatment
Operation
23,040
23,040
23,040
Pre Treatment
Infrastructure
0.20
0.20
0.20
Fine screening
Operation
7,083
7,083
7,083
Infrastructure
0.87
0.87
0.87
Heating of influent
26,745,500
26,745,500
26,745,500
MBR pump
70,027
70,027
70,027
Heat loss control
14,144
14,144
14,144
MBR operation
Recovery of methane
-1,602,130
-1,602,130
-1,602,130
Effluent pumping out
237,666
237,666
237,666
Heat recovery from discharge water
-21,063,200
-21,063,200
-21,063,200
Biogas recirculation pump
10,907
10,907
10,907
Sodium hypochlorite, 15%
61,775
61,775
61,775
MBR
Infrastructure
178,293
178,293
178,293
Operation
78,179
78,179
78,179
Post treatment
Chlorination
Sodium hypochlorite, 15%
167,159
167,159
167,159
Infrastructure
627
627
627
Operation
129,905
35,795
16,973
Pipe infrastructure
14,743
4,021
1,876
Recycled water delivery
Pipe installation
274
74.8
34.9
Displaced drinking water
-5,314,540
-5,314,540
-5,314,540
Methane emissions from permeate
2,008,360
2,008,360
2,008,360
Net Impact
1,870,749
1,758,581
1,735,822
A-24
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-25. Detailed Global Warming Potential Results for 10 MGD AnMBR, 35°C
Reactor Temperature (kg C02 eq/Year)
Water treated per year (m3)
13.825.907
13.825.907
13.825.907
10 MGD AnMBR
[single family]
10 MGD
AnMBR
[multi family]
10 MGD
AnMBR
[high density
urban]
Pipe infrastructure
22,350
5,924
2,845
Wastewater collection
Pipe installation
2,184
893
449
Operation
184,908
184,908
184,908
Preliminary
treatment
Operation
31,791
31,791
31,791
Pre Treatment
Infrastructure
0.39
0.39
0.39
Fine screening
Operation
14,166
14,166
14,166
Infrastructure
1.73
1.73
1.73
Heating of influent
53,491,000
53,491,000
53,491,000
MBR pump
140,053
140,053
140,053
Heat loss control
24,175
24,175
24,175
MBR operation
Recovery of methane
-3,204,260
-3,204,260
-3,204,260
Effluent pumping out
475,333
475,333
475,333
Heat recovery from discharge water
-42,126,300
-42,126,300
-42,126,300
Biogas recirculation pump
21,813
21,813
21,813
Sodium hypochlorite, 15%
111,195
111,195
111,195
MBR
Infrastructure
320,777
320,777
320,777
Operation
89,561
89,561
89,561
Post treatment
Chlorination
Sodium hypochlorite, 15%
334,318
334,318
334,318
Infrastructure
1,016
1,016
1,016
Operation
259,305
71,086
33,442
Pipe infrastructure
29,506
8,037
3,752
Recycled water delivery
Pipe installation
548
150
69.7
Displaced drinking water
-10,625,900
-10,625,900
-10,625,900
Methane emissions from permeate
4,080,460
4,080,460
4,080,460
Net Impact
3,678,000
3,450,198
3,404,666
A-25
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-26. Detailed Global Warming Potential Results for 0.05 MGD AnMBR, 20°C
Reactor Temperature (kg CO2 eq/Year)
Water treated per year (m3)
69.130
69.130
69.130
69.130
0.05 MGD
AnMBR [semi
rural single
family]
0.05 MGD
AnMBR
[single
family]
0.05 MGD
AnMBR
[multi
family]
0.05 MGD
AnMBR
[high
density
urban]
Pipe infrastructure
229
116
30.5
14.4
Wastewater collection
Pipe installation
22.3
10.9
2.98
1.39
Operation
925
925
925
925
Preliminary
treatment
Operation
2,735
2,735
2,735
2,735
Pre Treatment
Infrastructure
0.0020
0.0020
0.0020
0.0020
Fine
Operation
68.4
68.4
68.4
68.4
screening
Infrastructure
0.0087
0.0087
0.0087
0.0087
Heating of influent
0
0
0
0
MBR pump
700
700
700
700
Heat loss control
0
0
0
0
MBR operation
Recovery of methane
-14,241
-14,241
-14,241
-14,241
Effluent pumping out
2,377
2,377
2,377
2,377
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
109
109
109
109
Sodium hypochlorite, 15%
1,001
1,001
1,001
1,001
MBR
Infrastructure
3,293
3,293
3,293
3,293
Operation
31,253
31,253
31,253
31,253
Post treatment
Chlorination
Sodium hypochlorite, 15%
1,671
1,671
1,671
1,671
Infrastructure
242
242
242
242
Operation
3,151
1,798
857
669
Pipe infrastructure
301
148
40.2
18.8
Recycled water delivery
Pipe installation
5.60
2.75
0.75
0.36
Displaced drinking water
-52,862
-52,862
-52,862
-52,862
Methane emissions from permeate
26,284
26,284
26,284
26,284
Net Impact
7,264
5,631
4,487
4,259
A-26
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-27. Detailed Global Warming Potential Results for 0.1 MGD AnMBR, 20°C
Reactor Temperature (kg C02 eq/Year)
Water treated per year (m3)
138.259
138.259
138.259
138.259
0.1 MGD
AnMBR [semi
rural single
family]
0.1 MGD
AnMBR
[single family]
0.1 MGD
AnMBR
[multi
family]
0.1 MGD
AnMBR
[high density
urban]
Pipe infrastructure
427
223
61.0
27.9
Wastewater collection
Pipe installation
44.7
21.8
5.96
4.17
Operation
1,849
1,849
1,849
1,849
Preliminary
treatment
Operation
3,767
3,767
3,767
3,767
Pre Treatment
Infrastructure
0.0039
0.0039
0.0039
0.0039
Fine
Operation
137
137
137
137
screening
Infrastructure
0.017
0.017
0.017
0.017
Heating of influent
0
0
0
0
MBR pump
1,401
1,401
1,401
1,401
Heat loss control
0
0
0
0
MBR operation
Recovery of methane
-28,482
-28,482
-28,482
-28,482
Effluent pumping out
4,754
4,754
4,754
4,754
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
218
218
218
218
Sodium hypochlorite, 15%
2,003
2,003
2,003
2,003
MBR
Infrastructure
3,475
3,475
3,475
3,475
Post
treatment
Operation
35,878
35,878
35,878
35,878
Chlorination
Sodium hypochlorite, 15%
3,343
3,343
3,343
3,343
Infrastructure
245
245
245
245
Operation
5,797
3,092
1,210
833
Pipe infrastructure
603
294
80.1
37.5
Recycled water delivery
Pipe installation
11.2
5.48
1.50
0.69
Displaced drinking water
-105,815
-105,815
-105,815
-105,815
Methane emissions from permeate
52,614
52,614
52,614
52,614
Net Impact
-17,730
-20,977
-23,255
-23,710
A-27
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-28. Detailed Global Warming Potential Results for 1 MGD AnMBR, 20°C Reactor
Temperature (kg C02 eq/Year)
Water treated per year (m3)
1.382.591 1.382.591 1.382.591 1.382.591
1 MGD AnMBR
[semi rural single
family]
1 MGD
AnMBR
[single family]
1 MGD
AnMBR
[multi
family]
1 MGD
AnMBR
[high
density
urban]
Wastewater collection
Pipe infrastructure
4,572
2,235
610
284
Pipe installation
447
218
59.6
32.0
Operation
18,491
18,491
18,491
18,491
Pre Treatment
Preliminary
treatment
Operation
10,939
10,939
10,939
10,939
Infrastructure
0.039
0.039
0.039
0.039
Fine
screening
Operation
1,415
1,415
1,415
1,415
Infrastructure
0.17
0.17
0.17
0.17
MBR operation
Heating of influent
0
0
0
0
MBR pump
14,005
14,005
14,005
14,005
Heat loss control
0
0
0
0
Recovery of methane
-284,823
-284,823
-284,823
-284,823
Effluent pumping out
47,534
47,534
47,534
47,534
Heat recovery from discharge water
0
0
0
0
Biogas recirculation pump
2,181
2,181
2,181
2,181
Sodium hypochlorite, 15%
14,826
14,826
14,826
14,826
MBR
Infrastructure
42,772
42,772
42,772
42,772
Post
treatment
Chlorination
Operation
56,745
56,745
56,745
56,745
Sodium hypochlorite, 15%
34,330
34,330
34,330
34,330
Infrastructure
316
316
316
316
Recycled water delivery
Operation
53,441
30,920
7,562
3,798
Pipe infrastructure
6,032
2,952
776
375
Pipe installation
112
54.8
15.0
6.88
Displaced drinking water
-1,061,840
-1,061,840
-1,061,840
-1,061,840
Methane emissions from permeate
527,970
527,970
527,970
527,970
Net Impact
-510,535
-538,759
-566,116
-570,642
A-28
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-29. Detailed Global Warming Potential Results for 5 MGD AnMBR, 20°C Reactor
Temperature (kg C02 eq/Year)
Water treated per year (m3)
6.912.954 6.912.954 6.912.954
5 MGD AnMBR
[single family]
5 MGD AnMBR
[multi family]
5 MGD AnMBR
[high density
urban]
Wastewater collection
Pipe infrastructure
9,391
3,048
1,422
Pipe installation
1,092
298
171
Operation
92,454
92,454
92,454
Pre Treatment
Preliminary
treatment
Operation
23,040
23,040
23,040
Infrastructure
0.20
0.20
0.20
Fine
screening
Operation
7,083
7,083
7,083
Infrastructure
0.87
0.87
0.87
MBR operation
Heating of influent
0
0
0
MBR pump
70,027
70,027
70,027
Heat loss control
0
0
0
Recovery of methane
-1,424,110
-1,424,110
-1,424,110
Effluent pumping out
237,666
237,666
237,666
Heat recovery from discharge water
0
0
0
Biogas recirculation pump
10,907
10,907
10,907
Sodium hypochlorite, 15%
61,775
61,775
61,775
MBR
Infrastructure
178,293
178,293
178,293
Post treatment
Chlorination
Operation
78,179
78,179
78,179
Sodium hypochlorite, 15%
167,159
167,159
167,159
Infrastructure
627
627
627
Recycled water delivery
Operation
129,905
35,795
16,973
Pipe infrastructure
14,743
4,021
1,876
Pipe installation
274
74.8
34.9
Displaced drinking water
-5,314,540
-5,314,540
-5,314,540
Methane emissions from permeate
2,600,450
2,600,450
2,600,450
Net Impact
-3,055,585
-3,167,753
-3,190,512
A-29
-------
AppendixA-DetailedEnergy and GWP Baseline Results
Table A-30. Detailed Global Warming Potential Results for 10 MGD AnMBR, 20°C
Reactor Temperature (kg C02 eq/Year)
Water treated per year (m3)
13.825.907 13.825.907 13.825.907
10 MGD AnMBR
[single family]
10 MGD
AnMBR [multi
family]
10 MGD AnMBR
[high density urban]
Wastewater collection
Pipe infrastructure
22,350
5,924
2,845
Pipe installation
2,184
893
449
Operation
184,908
184,908
184,908
Pre Treatment
Preliminary
treatment
Operation
31,791
31,791
31,791
Infrastructure
0.39
0.39
0.39
Fine
screening
Operation
14,166
14,166
14,166
Infrastructure
1.73
1.73
1.73
MBR operation
Heating of influent
0
0
0
MBR pump
140,053
140,053
140,053
Heat loss control
0
0
0
Recovery of methane
-2,848,230
-2,848,230
-2,848,230
Effluent pumping out
475,333
475,333
475,333
Heat recovery from discharge water
0
0
0
Biogas recirculation pump
21,813
21,813
21,813
Sodium hypochlorite, 15%
111,195
111,195
111,195
MBR
Infrastructure
320,777
320,777
320,777
Post
treatment
Chlorination
Operation
89,561
89,561
89,561
Sodium hypochlorite, 15%
334,318
334,318
334,318
Infrastructure
1,016
1,016
1,016
Recycled water delivery
Operation
259,305
71,086
33,442
Pipe infrastructure
29,506
8,037
3,752
Pipe installation
548
150
69.7
Displaced drinking water
-10,625,900
-10,625,900
-10,625,900
Methane emissions from permeate
5,283,430
5,283,430
5,283,430
Net Impact
-6,151,875
-6,379,677
-6,425,209
A-30
-------
Appendix B-Full Baseline LCIA Results
Appendix B
Full Baseline LCIA Results
-------
Appendix B-Full Baseline LCIA Results
Appendix B - Full Baseline LCIA Results
This Appendix presents the summary results for all LCIA indicators evaluated. Table B-l
through Table B-5 provide the LCIA summary results for the AeMBR scenarios. Summary
LCIA results for all AnMBR scenarios, with the reactor operating at 35 C are shown in Table B-
6 through Table B-10. Summary LCIA results for the AnMBR operating at ambient temperature
are illustrated in Table B-l 1 through Table B-l5.
Table B-l. LCIA Summary Results on Yearly Basis for 0.05 MGD AeMBR
Water treated per year (m3)
(.'J. 1 "in
<¦'>. no
(.'J. 1 ^0
(.'J. 1 .0
0.05 MGD
0.05
0.05 MGD
AeMBR
MGD
0.05 MGD
AeMBR
[semi rural
AeMBR
AeMBR
[high
single
[single
[multi
density
family]
family]
family!
urban]
Acidification
kg S02 eq
321
308
298
296
Eco toxicity
CTUe
295
277
265
262
Energy Demand
MJ
573,879
548,146
530,063
526,472
Eutrophication
kgN eq
20.0
19.7
19.4
19.4
Fossil Depletion
kg oil eq
9,357
8,907
8,591
8,528
Global Warming
kg C02 eq
37,230
35,597
34,453
34,225
Human Health Criteria
kgPM2.5 eq
17.3
16.6
16.1
16.0
Human Health Cancer
CTUh
1.2E-06
9.3E-07
7.1E-07
6.6E-07
Human Health NonCancer
CTUh
0.089
0.086
0.084
0.084
Ozone Depletion
kg CFC-11 eq
0.0010
9.8E-04
9.5E-04
9.5E-04
Smog
kg 03 eq
2,469
2,365
2,293
2,279
Water Depletion
m3
-64,875
-64,884
-64,890
-64,891
B-l
-------
Appendix B-Full Baseline LCIA Results
Table B-2. LCIA Summary Results on Yearly Basis for 0.1 MGD AeMBR
Water treated
per year (m3)
1
1 'X.:5<>
138.259
1 'X.:5<>
0.1 MGD
AeMBR
[semi rural
single
family]
0.1 MGD
AeMBR
[single
family]
0.1 MGD
AeMBR
[multi
family!
0.1 MGD
AeMBR
[high
density
urban]
Acidification
kg S02 eq
151
124
105
102
Eco toxicity
CTUe
478
443
419
414
Energy Demand
MJ
230,555
179,043
143,090
135,909
Eutrophication
kgN eq
31.9
31.2
30.7
30.6
Fossil Depletion
kg oil eq
3,220
2,320
1,691
1,566
Global Warming
kg C02 eq
16,390
13,144
10,865
10,410
Human Health Criteria
kgPM2.5 eq
8.76
7.30
6.28
6.08
Human Health Cancer
CTUh
1.2E-06
6.1E-07
1.6E-07
7.2E-08
Human Health NonCancer
CTUh
0.083
0.077
0.073
0.072
Ozone Depletion
kg CFC-11 eq
7.7E-04
6.9E-04
6.4E-04
6.3E-04
Smog
kg 03 eq
1,526
1,322
1,178
1,149
Water Depletion
m3
-130,095
-130,112
-130,125
-130,127
Table B-3. LCIA Summary Results on Yearly Basis for 1 MGD AeMBR
Water treated
per year (m3)
nx:.5i>i
l.^s:.5'H
l.^x:.5lH
1 MGD
AeMBR [semi
rural single
family]
1 MGD
AeMBR
[single
family]
1 MGD
AeMBR
[multi family]
1 MGD
AeMBR
[high density
urban]
Acidification
kg S02 eq
-3,832
-4,064
-4,292
-4,330
Eco toxicity
CTUe
3,702
3,349
3,101
3,052
Energy Demand
MJ
-6,756,690
-7,200,452
-7,633,332
-7,705,003
Eutrophication
kgN eq
232
225
219
218
Fossil Depletion
kg oil eq
-136,244
-144,052
-151,578
-152,833
Global Warming
kg C02 eq
-464,890
-493,115
-520,472
-524,998
Human Health Criteria
kgPM2.5 eq
-193
-206
-218
-220
Human Health Cancer
CTUh
-1.2E-06
-7.4E-06
-1.2E-05
-1.3E-05
Human Health NonCancer
CTUh
-0.20
-0.25
-0.31
-0.31
Ozone Depletion
kg CFC-11 eq
-0.0060
-0.0066
-0.0072
-0.0073
Smog
kg 03 eq
-21,733
-23,537
-25,251
-25,538
Water Depletion
m3
-1,304,680
-1,304,820
-1,304,970
-1,304,990
B-2
-------
Appendix B-Full Baseline LCIA Results
Table B-4. LCIA Summary Results on Yearly Basis for 5 MGD AeMBR
Water treated
per year (m3)
2.^54
12.^54
(>.lH 2.^54
5 MGD
AeMBR
[single family]
5 MGD
AeMBR
[multi family]
5 MGD
AeMBR
[high density
urban]
Acidification
kg S02 eq
-23,074
-24,003
-24,192
Ecotoxicity
CTUe
16,128
14,896
14,659
Energy Demand
MJ
-45,730,658
-47,514,952
-47,874,045
Eutrophication
kgN eq
1,044
1,019
1,014
Fossil Depletion
kg oil eq
-807,708
-838,879
-845,157
Global Wanning
kg C02 eq
-2,794,540
-2,906,708
-2,929,467
Human Health Criteria
kg PM 2.5 eq
-1,176
-1,227
-1,237
Human Health Cancer
CTUh
-4.7E-05
-6.6E-05
-7.1E-05
Human Health NonCancer
CTUh
-1.82
-2.04
-2.08
Ozone Depletion
kg CFC-11 eq
-0.041
-0.043
-0.044
Smog
kg 03 eq
-136,675
-143,721
-145,154
Water Depletion
m3
-6,526,020
-6,526,620
-6,526,740
Table B-5. LCIA Summary Results on Yearly Basis for 10 MGD AeMBR
Water treated per
year (m3)
i vx:.v«r
13.825.907
1 vX25.'J
-------
Appendix B-Full Baseline LCIA Results
Table B-6. LCIA Summary Results on Yearly Basis for 0.05 MGD AnMBR (35°C)
Water treated
per year (m3)
69.130
i<1). 1 i()
69.130
i.'J.nu
0.05 MGD
AnMBR
[semi rural
single
family]
0.05 MGD
AnMBR
[single
family]
0.05 MGD
AnMBR
[multi
family]
0.05 MGD
AnMBR
[high density
urban]
Acidification
kg S02 eq
-125
-139
-148
-150
Ecotoxicity
CTUe
338
321
308
306
Energy Demand
MJ
563,197
537,464
519,380
515,790
Eutrophication
kgN eq
25.5
25.1
24.9
24.8
Fossil Depletion
kg oil eq
15,748
15,298
14,981
14,918
Global Wanning
kg C02 eq
57,138
55,505
54,361
54,134
Human Health Criteria
kg PM 2.5 eq
-6.00
-6.73
-7.24
-7.35
Human Health Cancer
CTUh
3.0E-07
-1.9E-08
-2.4E-07
-2.9E-07
Human Health NonCancer
CTUh
0.034
0.031
0.029
0.029
Ozone Depletion
kg CFC-11 eq
-1.2E-04
-1.6E-04
-1.8E-04
-1.9E-04
Smog
kg 03 eq
221
118
45.4
31.1
Water Depletion
m3
-65,909
-65,918
-65,924
-65,925
Table B-7. LCIA Summary Results on Yearly Basis for 0.1 MGD AnMBR (35°C)
Water treated
per year (m3)
1
1
1 iX.25lJ
1
0.1 MGD
AnMBR
[semi rural
single family]
0.1 MGD
AnMBR
[single
family]
0.1 MGD
AnMBR
[multi
family]
0.1 MGD
AnMBR
[high density
urban]
Acidification
kg S02 eq
-516
-543
-562
-565
Ecotoxicity
CTUe
554
519
494
490
Energy Demand
MJ
627,664
576,152
540,199
533,019
Eutrophication
kgN eq
40.2
39.5
39.0
38.9
Fossil Depletion
kg oil eq
22,795
21,894
21,266
21,140
Global Wanning
kg C02 eq
81,541
78,295
76,016
75,561
Human Health Criteria
kg PM 2.5 eq
-26.2
-27.7
-28.7
-28.9
Human Health Cancer
CTUh
-1.8E-07
-7.5E-07
-1.2E-06
-1.3E-06
Human Health NonCancer
CTUh
0.013
0.0067
0.0023
0.0014
Ozone Depletion
kg CFC-11 eq
-0.0010
-0.0011
-0.0012
-0.0012
Smog
kg 03 eq
-1,394
-1,599
-1,743
-1,771
Water Depletion
m3
-132,136
-132,154
-132,166
-132,168
B-4
-------
Appendix B-Full Baseline LCIA Results
Table B-8. LCIA Summary Results on Yearly Basis for 1 MGD AnMBR (35°C)
Water treated
per year (m3)
nxi5l>l
nx:.5i>i
nxi5l>l
1 MGD
AnMBR [semi
rural single
family]
1 MGD
AnMBR
[single
family]
1 MGD
AnMBR
[multi
family]
1 MGD
AnMBR
[high
density
urban]
Acidification
kg S02 eq
-8,246
-8,303
-8,706
-8,743
Eco toxicity
CTUe
3,782
4,478
3,181
3,132
Energy Demand
MJ
1,795,710
1,351,948
919,068
847,397
Eutrophication
kgN eq
255
345
243
242
Fossil Depletion
kg oil eq
125,224
125,570
109,891
108,635
Global Warming
kg C02 eq
474,272
446,048
418,691
414,165
Human Health Criteria
kg PM 2.5 eq
-428
-428
-453
-455
Human Health Cancer
CTUh
-9.6E-06
-1.5E-05
-2.0E-05
-2.1E-05
Human Health NonCancer
CTUh
-0.54
-0.49
-0.64
-0.65
Ozone Depletion
kg CFC-11 eq
-0.020
-0.018
-0.021
-0.021
Smog
kg 03 eq
-35,489
-36,212
-39,008
-39,294
Water Depletion
m3
-1,328,340
-1,328,080
-1,328,630
-1,328,660
Table B-9. LCIA Summary Results on Yearly Basis for 5 MGD AnMBR (35°C)
Water treated per
year (m3)
2.^54
I :.<)54
<>.'>12.^54
5 MGD
AnMBR
[single family]
5 MGD
AnMBR
[multi family]
5 MGD
AnMBR
[high density
urban]
Acidification
kg S02 eq
-43,876
-44,806
-44,994
Eco toxicity
CTUe
20,307
19,075
18,838
Energy Demand
MJ
-2,883,092
-4,667,387
-5,026,480
Eutrophication
kgN eq
1,534
1,509
1,504
Fossil Depletion
kg oil eq
547,035
515,863
509,585
Global Warming
kg C02 eq
1,870,749
1,758,581
1,735,822
Human Health Criteria
kgPM2.5 eq
-2,270
-2,321
-2,331
Human Health Cancer
CTUh
-8.5E-05
-1.0E-04
-1.1E-04
Human Health NonCancer
CTUh
-3.02
-3.24
-3.28
Ozone Depletion
kg CFC-11 eq
-0.10
-0.10
-0.10
Smog
kg 03 eq
-197,687
-204,734
-206,167
Water Depletion
m3
-6,649,020
-6,649,620
-6,649,740
B-5
-------
Appendix B-Full Baseline LCIA Results
Table B-10. LCIA Summary Results on Yearly Basis for 10 MGD AnMBR (35°C)
Water treated per
year (m3)
I vx:.\'«r
1 vS:5.^)-
1 VXlVfl)"
10 MGD
AnMBR [single
family]
10 MGD
AnMBR [multi
family]
10 MGD
AnMBR [high
density urban]
Acidification
kg S02 eq
-88,646
-90,529
-90,906
Eco toxicity
CTUe
38,682
36,303
35,774
Energy Demand
MJ
-7,739,946
-11,332,727
-12,052,451
Eutrophication
kgN eq
2,897
2,847
2,837
Fossil Depletion
kg oil eq
1,060,140
997,326
984,731
Global Warming
kg C02 eq
3,678,000
3,450,198
3,404,666
Human Health Criteria
kgPM2.5 eq
-4,594
-4,696
-4,716
Human Health Cancer
CTUh
-1.7E-04
-2.1E-04
-2.2E-04
Human Health NonCancer
CTUh
-6.32
-6.76
-6.85
Ozone Depletion
kg CFC-11 eq
-0.20
-0.21
-0.21
Smog
kg 03 eq
-401,570
-415,925
-418,830
Water Depletion
m3
-13,295,000
-13,296,200
-13,296,400
Table B-ll. LCIA Summary Results on Yearly Basis for 0.05 MGD AnMBR (20°C)
Water treated
per year (m3)
(••>. 1 .()
(.'J. 1 .()
(.'J. 1 .()
0.05 MGD
AnMBR
[semi rural
single
family]
0.05 MGD
AnMBR
[single
family]
0.05 MGD
AnMBR
[multi
family]
0.05 MGD
AnMBR
[high density
urban]
Acidification
kg S02 eq
-180
-193
-203
-205
Ecotoxicity
CTUe
328
310
298
295
Energy Demand
MJ
-360,134
-385,867
-403,951
-407,542
Eutrophication
kgN eq
21.2
20.8
20.6
20.5
Fossil Depletion
kg oil eq
-6,186
-6,635
-6,952
-7,015
Global Warming
kg C02 eq
7,264
5,631
4,487
4,259
Human Health Criteria
kgPM2.5 eq
-8.64
-9.37
-9.89
-9.99
Human Health Cancer
CTUh
4.2E-08
-2.8E-07
-5.0E-07
-5.4E-07
Human Health NonCancer
CTUh
-7.5E-04
-0.0039
-0.0061
-0.0066
Ozone Depletion
kg CFC-11 eq
-9.8E-05
-1.3E-04
-1.6E-04
-1.7E-04
Smog
kg 03 eq
-960
-1,063
-1,136
-1,150
Water Depletion
m3
-65,899
-65,907
-65,913
-65,914
B-6
-------
Appendix B-Full Baseline LCIA Results
Table B-12. LCIA Summary Results on Yearly Basis for 0.1 MGD AnMBR (20°C)
Water treated per
year (m3)
1
138.259
1 'X.:5l>
1 'X.:5<>
0.1 MGD
0.1 MGD
0.1 MGD
0.1 MGD
AnMBR
AnMBR
AnMBR
AnMBR
[semi rural
single family]
[single
family]
[multi
family]
[high density
urban]
Acidification
kg S02 eq
-624
-651
-670
-674
Eco toxicity
CTUe
533
497
473
469
Energy Demand
MJ
-1,211,274
-1,262,786
-1,298,739
-1,305,920
Eutrophication
kgN eq
31.7
31.0
30.5
30.4
Fossil Depletion
kg oil eq
-20,890
-21,790
-22,419
-22,544
Global Warming
kg C02 eq
-17,730
-20,977
-23,255
-23,710
Human Health Criteria
kgPM2.5 eq
-31.5
-32.9
-33.9
-34.1
Human Health Cancer
CTUh
-6.9E-07
-1.3E-06
-1.7E-06
-1.8E-06
Human Health NonCancer
CTUh
-0.057
-0.063
-0.068
-0.069
Ozone Depletion
kg CFC-11 eq
-0.0010
-0.0011
-0.0011
-0.0011
Smog
kg 03 eq
-3,746
-3,950
-4,094
-4,123
Water Depletion
m3
-132,115
-132,132
-132,144
-132,147
Table B-13. LCIA Summary Results on Yearly Basis for 1 MGD AnMBR (20°C)
Water treated per
year (m3)
l.^s:.5'H
nx:.5i>i
1.^X2.5<>l
1.^X2.5<>l
1 MGD
1 MGD
1 MGD
AnMBR
AnMBR
1 MGD
AnMBR
[high
[semi rural
single family]
AnMBR
[single family]
[multi
family]
density
urban]
Acidification
kg S02 eq
-9,323
-9,380
-9,783
-9,820
Eco toxicity
CTUe
3,570
4,266
2,970
2,920
Energy Demand
MJ
-16,469,959
-16,913,720
-17,346,601
-17,418,271
Eutrophication
kgN eq
170
261
158
157
Fossil Depletion
kg oil eq
-308,703
-308,356
-324,036
-325,291
Global Warming
kg C02 eq
-510,535
-538,759
-566,116
-570,642
Human Health Criteria
kgPM2.5 eq
-480
-480
-505
-507
Human Health Cancer
CTUh
-1.5E-05
-2.0E-05
-2.6E-05
-2.6E-05
Human Health NonCancer
CTUh
-1.23
-1.19
-1.34
-1.35
Ozone Depletion
kg CFC-11 eq
-0.020
-0.018
-0.021
-0.021
Smog
kg 03 eq
-58,834
-59,557
-62,352
-62,639
Water Depletion
m3
-1,328,120
-1,327,870
-1,328,420
-1,328,440
B-7
-------
Appendix B-Full Baseline LCIA Results
Table B-14. LCIA Summary Results on Yearly Basis for 5 MGD AnMBR (20°C)
Water treated per
year (m3)
2.^54
12.^54
(>.lH 2.^54
5 MGD
AnMBR
[single family]
5 MGD
AnMBR
[multi family]
5 MGD
AnMBR
[high density
urban]
Acidification
kg S02 eq
-49,252
-50,182
-50,370
Ecotoxicity
CTUe
19,250
18,018
17,781
Energy Demand
MJ
-94,102,172
-95,886,467
-96,245,560
Eutrophication
kgN eq
1,110
1,085
1,080
Fossil Depletion
kg oil eq
-1,620,020
-1,651,190
-1,657,470
Global Wanning
kg C02 eq
-3,055,585
-3,167,753
-3,190,512
Human Health Criteria
kg PM 2.5 eq
-2,531
-2,581
-2,591
Human Health Cancer
CTUh
-1.1E-04
-1.3E-04
-1.3E-04
Human Health NonCancer
CTUh
-6.50
-6.72
-6.76
Ozone Depletion
kg CFC-11 eq
-0.098
-0.10
-0.10
Smog
kg 03 eq
-314,266
-321,312
-322,745
Water Depletion
m3
-6,647,940
-6,648,540
-6,648,660
Table B-15. LCIA Summary Results on Yearly Basis for 10 MGD AnMBR (20°C)
Water treated
per year (m3)
1 VXIVJU"
13.825.907
1 \X25.W
10 MGD
AnMBR [single
family]
10 MGD
AnMBR [multi
family]
10 MGD
AnMBR [high
density urban]
Acidification
kg S02 eq
-99,391
-101,275
-101,651
Ecotoxicity
CTUe
36,569
34,190
33,661
Energy Demand
MJ
-190,110,189
-193,702,970
-194,422,694
Eutrophication
kgN eq
2,050
2,000
1,990
Fossil Depletion
kg oil eq
-3,272,360
-3,335,180
-3,347,770
Global Warming
kg C02 eq
-6,151,875
-6,379,677
-6,425,209
Human Health Criteria
kg PM 2.5 eq
-5,114
-5,216
-5,237
Human Health Cancer
CTUh
-2.2E-04
-2.6E-04
-2.7E-04
Human Health NonCancer
CTUh
-13.3
-13.7
-13.8
Ozone Depletion
kg CFC-11 eq
-0.20
-0.21
-0.21
Smog
kg 03 eq
-634,623
-648,978
-651,883
Water Depletion
m3
-13,292,800
-13,294,000
-13,294,300
B-8
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Appendix C
Detailed Life Cycle Cost Analysis Results
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Appendix C - Detailed Life Cycle Cost Analysis Results
Detailed cost results for baseline scenarios are presented in Table C-l through Table C-7.
Detailed cost results are provided for the sensitivity analysis performed in Section 5 in Table C-8
and Table C-9.
Table C-l. Detailed Cost Results for AeMBR WWT Facilities ($/Year)
Water treated per year (m3)
69.130
138.259
1.382.591
6.912.954
13.825.907
0.05 MGD
AeMBR
0.1 MGD
AeMBR
1 MGD
AeMBR
5 MGD
AeMBR
10 MGD
AeMBR
Amortized Capital Cost
206,783
248,937
774,819
2,633,319
4,434,612
Operation - Labor
203,470
227,700
431,590
911,300
1,438,800
Operation and
Maintenance
(O&M) Cost
Maintenance - Labor
51,693
57,884
109,500
213,890
317,320
Materials
37,991
35,674
45,330
129,290
193,300
Chemicals
666
1,326
13,228
65,102
130,165
Energy Cost
11,832
15,420
64,507
279,541
533,823
Net Total Cost
512,435
586,941
1,438,973
4,232,442
7,048,020
Table C-2. Detailed Cost Results for the AnMBRWWT Facilities Operating at 35°C
($/Year)
Water treated per year (mS)
69.130
138.259
1.382.591
6.912.954
13.825.907
0.05 MGD
AnMBR
0.1 MGD
AnMBR
1 MGD
AnMBR
5 MGD
AnMBR
10 MGD
AnMBR
Amortized Capital Cost
251,265
305,614
1,021,423
3,797,222
7,165,747
Operation
and
Operation - Labor
259,180
318,633
1,271,990
4,261,850
7,569,450
Maintenance - Labor
64,530
87,619
512,148
1,975,949
3,600,776
Maintenance
(O&M) Cost
Materials
31,928
35,099
71,578
257,024
453,831
Chemicals
907
1,814
16,373
77,671
151,151
Energy Cost
Energy Demand
19,408
25,901
209,010
1,008,711
2,004,555
Electricity Generated
-2,553
-5,106
-51,063
-255,314
-510,627
Net Total Cost
624,664
769,574
3,051,460
11,123,114
20,434,883
Table C-3. Detailed Cost Results for the AnMBRWWT Facilities Operating at 20°C
($/Year)
Water treated per year (m3)
69.130
138.259
1.382.591
6.912.954
13.825.907
0.05 \1( ,1)
AnMBR
0.1 MGD
AnMBR
1 MGD
AnMBR
5 MGD
AnMBR
10 \1GD
AnMBR
Amortized Capital Cost
250,491
304,510
1,016,655
3,779,655
7,134,650
Operation - Labor
259,180
318,633
1,271,990
4,261,850
7,569,450
Operation and
Maintenance
(O&M) Cost
Maintenance - Labor
64,530
87,619
512,148
1,975,949
3,600,776
Materials
31,928
35,099
71,578
257,024
453,831
Chemicals
907
1,814
16,373
77,671
151,151
Energy Cost
Energy Demand
5,448
6,731
19,119
60,858
109,845
Electricity Generated
-2,292
-4,585
-45,848
-229,238
-458,476
Net Total Cost
610,191
749,822
2,862,016
10,183,769
18,561,228
C-l
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Table C-4. Detailed Cost Results for Construction and Operation of the Recycled Water
Delivery System ($/Year)
Amortized
Capital Cost
O&M Cost
I ¦!nemv Cost
Total Cost
0.05 MGD [semi rural single family]
69,428
2,377
463
72.2 M
0.05 MGD [single family]
33,943
1,162
264
35,369
0.05 MGD [multi family]
9,257
317
126
9,700
0.05 MGD [high density urban]
4,320
148
98
4,566
0.1 MGD [semi rural single family]
138,856
4,753
853
144,462
0.1 MGD [single family]
67,885
2,324
455
70,664
0.1 MGD [multi family]
18,514
634
178
19,326
0.1 MGD [high density urban]
8,640
296
123
9,058
1 MGD [semi rural single family]
1,388,565
47,531
7,860
1,443,956
1 MGD [single family]
678,854
23,237
3,880
705,972
1 MGD [multi family]
185,142
6,337
1,112
192,592
1 MGD [high density urban]
86,400
2,957
559
89,916
5 MGD [single family]
3,394,270
116,186
19,106
3,529,562
5 MGD [multi family]
925,710
31,687
5,265
962,662
5 MGD [high density urban]
431,998
14,787
2,496
449,282
10 MGD [single family]
6,788,540
232,373
38,138
7,059,050
10 MGD [multi family]
1,851,420
63,374
10,455
1,925,249
10 MGD [high density urban]
863,996
29,575
4,919
898,489
Table C-5. Detailed Combined AeMBR, Recycled Water delivery, and Avoided DWT Cost
Results ($/Year)
Water
treated pe
year (m3j
Amortized
Capital Cost
()&M Cost
I -Inersiv Cost
Avoided
l)\YT Cost
Total Cost
0.05 MGD [semi rural single family]
69,130
276,211
296,196
12,295
-4,423
584,703
0.05 MGD [single family]
69,130
240,726
294,982
12,096
-4,423
547,804
0.05 MGD [multi family]
69,130
216,040
294,137
11,958
-4,423
522,135
0.05 MGD [high density urban]
69,130
211,103
293,968
11,930
-4,423
517,001
0.1 MGD [semi rural single family]
138,259
387,794
327,337
16,272
-8,846
731,403
0.1 MGD [single family]
138,259
316,823
324,908
15,874
-8,846
657,605
0.1 MGD [multi family]
138,259
267,452
323,218
15,597
-8,846
606,267
0.1 MGD [high density urban]
138,259
257,577
322,880
15,542
-8,846
595,999
1 MGD [semi rural single family]
1,382,591
2,163,384
647,178
72,367
-88,461
2,882,929
1 MGD [single family]
1,382,591
1,453,673
622,885
68,388
-88,461
2,144,945
1 MGD [multi family]
1,382,591
959,961
605,985
65,619
-88,461
1,631,565
1 MGD [high density urban]
1,382,591
861,218
602,605
65,066
-88,461
1,528,889
5 MGD [single family]
6,912,954
6,027,589
1,435,768
298,647
-442,303
7,762,004
5 MGD [multi family]
6,912,954
3,559,029
1,351,269
284,806
-442,303
5,195,104
5 MGD [high density urban]
6,912,954
3,065,317
1,334,369
282,038
-442,303
4,681,724
10 MGD [single family]
13,825,907
11,223,152
2,311,958
571,960
-884,606
14,107,071
10 MGD [multi family]
13,825,907
6,286,032
2,142,960
544,278
-884,606
8,973,270
10 MGD [high density urban]
13,825,907
5,298,608
2,109,160
538,741
-884,606
7,946,510
C-2
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Table C-6. Detailed Combined AnMBR (35 °C), Recycled Water Delivery, and Avoided
DWT Cost Results ($/Year)
Water
treated pe
year (m3)
Amortized
Capital Cost
()&M Cost
I Iner"v Cost
Avoided
DW T Cost
Total Cost
0.05 MGD [semi rural single family]
69,130
320,693
358,921
17,318
-4,471
692,462
0.05 MGD [single family]
69,130
285,207
357,707
17,119
-4,471
655,563
0.05 MGD [multi family]
69,130
260,522
356,862
16,981
-4,471
629,894
0.05 MGD [high density urban]
69,130
255,584
356,693
16,953
-4,471
624,760
0.1 MGD [semi rural single family]
138,259
444,470
447,919
21,647
-8,949
905,088
0.1 MGD [single family]
138,259
373,499
445,489
21,250
-8,949
831,289
0.1 MGD [multi family]
138,259
324,128
443,799
20,973
-8,949
779,951
0.1 MGD [high density urban]
138,259
314,254
443,461
20,917
-8,949
769,684
1 MGD [semi rural single family]
1,382,591
2,409,988
1,919,619
165,808
-89,801
4,405,615
1 MGD [single family]
1,382,591
1,700,277
1,895,326
161,828
-89,801
3,667,631
1 MGD [multi family]
1,382,591
1,206,565
1,878,426
159,060
-89,801
3,154,250
1 MGD [high density urban]
1,382,591
1,107,823
1,875,046
158,506
-89,801
3,051,575
5 MGD [single family]
6,912,954
7,191,492
6,688,681
772,503
-449,457
14,203,219
5 MGD [multi family]
6,912,954
4,722,932
6,604,182
758,662
-449,457
11,636,319
5 MGD [high density urban]
6,912,954
4,229,220
6,587,282
755,894
-449,457
11,122,939
10 MGD [single family]
13,825,907
13,954,287
12,007,581
1,532,065
-898,643
26,595,290
10 MGD [multi family]
13,825,907
9,017,167
11,838,583
1,504,383
-898,643
21,461,490
10 MGD [high density urban]
13,825,907
8,029,743
11,804,783
1,498,846
-898,643
20,434,729
Table C-7. Detailed Combined AnMBR (20 °C), Recycled Water Delivery, and Avoided
DWT Cost Results ($/Year)
Water
treated per
year (mi)
Amortized
Capital Cost
O&M Cost
Knerav Cost
Avoided
DW T Cost
Total Cost
0.05 MGD [semi rural single family]
69,130
319,919
358,921
3,619
-4,471
6" 989
0.05 MGD [single family]
69,130
284,434
357,707
3,420
-4,471
641,090
0.05 MGD [multi family]
69,130
259,748
356,862
3,281
-4,471
615,421
0.05 MGD [high density urban]
69,130
254,811
356,693
3,254
-4,471
610,287
0.1 MGD [semi rural single family]
138,259
443,367
447,919
2,999
-8,949
885,335
0.1 MGD [single family]
138,259
372,395
445,489
2,601
-8,949
811,537
0.1 MGD [multi family]
138,259
323,024
443,799
2,324
-8,949
760,199
0.1 MGD [high density urban]
138,259
313,150
443,461
2,268
-8,949
749,931
1 MGD [semi rural single family]
1,382,591
2,405,220
1,919,619
-18,868
-89,801
4,216,171
1 MGD [single family]
1,382,591
1,695,509
1,895,326
-22,848
-89,801
3,478,187
1 MGD [multi family]
1,382,591
1,201,797
1,878,426
-25,616
-89,801
2,964,806
1 MGD [high density urban]
1,382,591
1,103,055
1,875,046
-26,170
-89,801
2,862,130
5 MGD [single family]
6,912,954
7,173,925
6,688,681
-149,274
-449,457
13,263,874
5 MGD [multi family]
6,912,954
4,705,365
6,604,182
-163,115
-449,457
10,696,974
5 MGD [high density urban]
6,912,954
4,211,653
6,587,282
-165,883
-449,457
10,183,594
10 MGD [single family]
13,825,907
13,923,190
12,007,581
-310,493
-898,643
24,721,636
10 MGD [multi family]
13,825,907
8,986,070
11,838,583
-338,176
-898,643
19,587,835
10 MGD [high density urban]
13,825,907
7,998,646
11,804,783
-343,712
-898,643
18,561,074
C-3
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Table C-8. Detailed Cost Results for Sensitivity Analysis of 1 MGD AnMBR WWT
Facilities ($/Year)
Amortized
Capital Cost
O&M Cost
I ¦iners v Cost
Total Cost
CN winter no insulation; biogas flare; permeate
methane recovery
1,009,618
1,872,089
270,460
3,152,167
CN winter no insulation; biogas flare; no
methane biogas recovery
1,009,314
1,872,089
269,663
3,151,066
CN winter no insulation; elect; no permeate
methane recovery
1,017,979
1,872,089
224,274
3,114,341
CN winter no insulation; elect; permeate
methane recovery
1,019,782
1,872,089
217,474
3,109,345
CN winter no insulation; CHP; no permeate
methane recovery
1,019,910
1,872,089
207,209
3,099,207
CN winter no insulation; CHP; permeate
methane recovery
1,022,047
1,872,089
197,250
3,091,386
CN winter w/ insulation; biogas flare; permeate
methane recovery
1,013,555
1,872,089
194,980
3,080,624
CN winter w/ insulation; biogas flare; no
permeate methane recovery
1,013,252
1,872,089
194,183
3,079,524
CN winter w/ insulation; elect; no permeate
methane recovery
1,021,916
1,872,089
148,794
3,042,799
CN winter w/ insulation; elect; permeate
methane recovery
1,023,719
1,872,089
141,994
3,037,802
CN winter w/ insulation; CHP; no permeate
methane recovery
1,023,847
1,872,089
131,729
3,027,665
CN winter w/ insulation; CHP; permeate
methane recovery
1,025,985
1,872,089
121,770
3,019,843
MIA; biogas flare; permeate methane recovery
1,009,634
1,872,089
19,977
2,901,700
MIA; biogas flare; no permeate methane
recovery
1,009,314
1,872,089
19,119
2,900,522
MIA; elect; no permeate methane recovery
1,018,479
1,872,089
-28,675
2,861,892
MIA; elect; permeate methane recovery
1,020,131
1,872,089
-34,605
3,152,167
MIA; CHP; no permeate methane recovery
1,020,521
1,872,089
-46,644
3,151,066
MIA; CHP; permeate methane recovery
1,022,471
1,872,089
-55,396
3,114,341
C-4
-------
Appendix C-Detailed Life Cycle Cost Analysis Results
Table C-9. Detailed Combined 1 MGD AnMBR, Recycled Water Delivery, and Avoided
DWT Cost Results for Sensitivity Analysis ($/Year)
Amortized
Capital Cost
O&M Cost
I ¦iners v Cost
Avoided
DWT Cost
Total Cost
CN winter no insulation; biogas flare; permeate
methane recovery
1,194,760
1,878,426
271,572
-89,801
3,254,958
CN winter no insulation; biogas flare; no
methane biogas recovery
1,194,456
1,878,426
270,775
-89,801
3,253,857
CN winter no insulation; elect; no permeate
methane recovery
1,203,121
1,878,426
225,386
-89,801
3,217,132
CN winter no insulation; elect; permeate
methane recovery
1,204,924
1,878,426
218,586
-89,801
3,212,135
CN winter no insulation; CHP; no permeate
methane recovery
1,205,052
1,878,426
208,321
-89,801
3,201,998
CN winter no insulation; CHP; permeate
methane recovery
1,207,189
1,878,426
198,362
-89,801
3,194,177
CN winter w/ insulation; biogas flare; permeate
methane recovery
1,198,697
1,878,426
196,093
-89,801
3,183,415
CN winter w/ insulation; biogas flare; no
permeate methane recovery
1,198,394
1,878,426
195,296
-89,801
3,182,314
CN winter w/ insulation; elect; no permeate
methane recovery
1,207,058
1,878,426
149,906
-89,801
3,145,589
CN winter w/ insulation; elect; permeate
methane recovery
1,208,861
1,878,426
143,107
-89,801
3,140,593
CN winter w/ insulation; CHP; no permeate
methane recovery
1,208,989
1,878,426
132,841
-89,801
3,130,455
CN winter w/ insulation; CHP; permeate
methane recovery
1,211,127
1,878,426
122,882
-89,801
3,122,634
MIA; biogas flare; permeate methane recovery
1,194,776
1,878,426
21,089
-89,801
3,004,491
MIA; biogas flare; no permeate methane
recovery
1,194,456
1,878,426
20,232
-89,801
3,003,313
MIA; elect; no permeate methane recovery
1,203,621
1,878,426
-27,563
-89,801
2,964,683
MIA; elect; permeate methane recovery
1,205,273
1,878,426
-33,492
-89,801
2,960,406
MIA; CHP; no permeate methane recovery
1,205,663
1,878,426
-45,532
-89,801
2,948,756
MIA; CHP; permeate methane recovery
1,207,613
1,878,426
-54,284
-89,801
2,941,954
C-5
-------
Appendix D-Ambient and Influent Wastewater Temperatures for Climate Scenarios
Appendix D
Ambient and Influent Wastewater Temperatures for Climate Scenarios
-------
Appendix D—Ambient and Influent Wastewater Temperatures for Climate Scenarios
Appendix D - Ambient and Influent Wastewater Temperature for Climate Scenarios
Influent wastewater temperature varies from ambient air temperature. Based on
information from Metcalf and Eddy (2014), influent wastewater temperature is often higher than
ambient air temperature. One reason for this is the addition of warmer water from household
activities. In addition, the specific heat of water is greater than air, so the wastewater temperature
is generally higher than air for most months except the warmest summer months. Figure D- 1
below shows influent wastewater temperature versus ambient air temperature for example
locations across the U.S. (with influent temperatures derived from Metcalf and Eddy (2014),
Figure 2-13).
El Paso Texas
Martinez California
40
30
20
10
0
0.0
20
0
-20
5.0
10.0
—•—Average Influent Temp °C
• Average Ambient Temp °C
Burlington Vermont
^Average Influent Temp °C
~—Average Ambient Temp °C
Ouray Colorado
15.0
15
15
30
20
10
0
30
25
20
15
10
5 10
• Average Influent Temp °C
—Average Ambient Temp °C
Greenville Alabama
5 10
—Average Influent Temp °C
—Average Ambient Temp °C
Wahiawa Hawaii
40
20
0
•=«-
15
15
10
15
-Average Influent Temp °C
-Average Ambient Temp °C
-Average Influent Temp °C
¦Average Ambient Temp °C
Figure D- 1. Ambient v. Influent Temperature throughout the Year for Sample Cities in
the U.S. (Adapted from Metcalf and Eddy 2014, Figure 2-13
D-l
-------
Appendix D—Ambient and Influent Wastewater Temperatures for Climate Scenarios
The annual ambient air temperature profile for Cincinnati most closely matches that of
Burlington Vermont (ambient air temperature on average is 6.8 degrees C below average influent
temperature). The annual ambient air temperature profile for Miami most closely matches that of
Wahiawa Hawaii (ambient air temperature on average is 1.3 degrees C below average influent
temperature). We can use these differentials to determine the relative influent wastewater
temperatures in the climate scenarios investigated in Section 5.0. Using this approach, we see the
following temperature profiles for our two climate scenarios (Figure D-2).
30
25
20
15
10
0 V
-5 0
Cincinnati Ohio
40
30
20
10
0
5 10
-Average Influent Temp °C
-Average Ambient Temp °C
15
Miami Florida
5 10
¦Average Influent Temp °C
-Average Ambient Temp °C
15
Figure D-2. Cincinnati, OH and Miami, FL Ambient V. Influent Temperature throughout
the Year
These profiles can be used to generate the ambient and influent temperature parameters
within the OpenLCA scenario analyses (Table D-l). It is assumed that May through September
represents "summer" and October through April is "winter." Miami, FL scenarios are not run for
different seasons as the influent and ambient temperatures remain relative constant throughout
the year.
Table D-l. Scenario Temperature Profiles for Miami, FL and Cincinnati, OH
Cincinnati, OH
Miami, FL
Annual Average Ambient Temp C
12.6
25.0
Annual Average Influent Temp C
19.4
26.4
May-Sept Ambient Temp C
21.6
May-Sept Influent Temp C
21.4
Oct-April Ambient Temp C
6.1
Oct-April Influent Temp C
17.9
D-2
-------
Appendix E-Biogas Flaring and Recovery with CHP
Appendix E
Biogas Flaring and Recovery with CHP
-------
Appendix E-Biogas Flaring and Recovery with CHP
Appendix E - Biogas Flaring and Recovery with CHP
Emissions inventory information for biogas flaring was compiled from three resources
with the maximum reported emission value for each compound being taken as the emission
factor for this project. Table E-l shows the data extracted from each study with the last column
displaying the emission factor selected for inclusion in this study. All emission factors in the
table are included as kg of compound emitted per cubic meter of biogas flared. Emission factors
from Levis and Barlaz 2013 are presented in the original study per cubic meter of biogas CH4
content.
Table E-l. Biogas Flaring Emission Factors (All values are kg/m3 Biogas Flared)
Compound
liiirlii/'1
Alhorlii
l.n\ ironim-iil1'
l.n\ ironim-iil
(;in;i(l;r
1 his Siudj
(M;i\ Ysiluc)
Nitrous Oxide
1.13E-05
3.50E-05
4.53E-04
4.53E-04
PM-Total
5.95E-05
8.49E-04
8.49E-04
PM10
1.02E-05
8.49E-04
8.49E-04
PM-2.5
4.66E-06
8.49E-04
8.49E-04
Nitrogen Oxides
1.22E-02
1.22E-02
NMVOCs
2.03E-05
2.03E-05
Sulfur Oxides
4.34E-04
9.21E-05
4.34E-04
Carbon
Monoxide
6.18E-03
5.56E-05
6.18E-03
Ammonia
1.82E-05
1.82E-05
Hydrogen Sulfide
3.92E-06
3.92E-06
PAH
8.71E-06
8.71E-06
a Levis, J.W., and Barlaz, M.A. 2013. Anaerobic Digestion Process Model Documentation. North Carolina State
University, http://www4.ncsu.edu/~iwlevis/AD.pdf Accessed 5 April, 2016.
b Alberta Environment. 2007. Quantification Protocol for the Anaerobic Decomposition of Agricultural Materials
Project: Excel Biogas Calculator. http://environment.gov.ab.ca/info/librarv/7917.pdf Accessed 5 April, 2016.
0 Environment Canada. 2005. Biogas Flare. https://www.ec.gc.ca/inrp-npri/14618D02-387B-469D-BlCD-
42BC61E51652/biogas flare e 04 02 2009.xls Accessed 5 April, 2016.
For methane recovery with CHP, the model assumes the energy not converted to electric
power is captured with a heat exchanger and used to heat the incoming influent. The power
available for heat is based on results from Equation 1 in the main report with adaptations for
available heat for power shown in Equation E-l.
HPch4 = ((PRch4*LHVch4) - EPaufMTeff (Eqn. E-1)
Where:
HPch4 = Heat power from recovered headspace methane in kW
PRch4 = Methane production rate (grams CH4/second)
LHVch4 = Lower heating value methane (modeled as 50 kJ/g)
EPCH4 = Electric power from recovered headspace methane in kW
MT eff = Microturbine efficiency (modeled as 34%)
E-l
-------
Appendix E-Biogas Flaring and Recovery with CHP
This calculation assumes the CHP system is a microturbine. Microturbines are the most
common type of CHP system for the size systems modeled in this study (U.S. EPA CHPP 2011).
The average heat recovery efficiency for a microturbine is 30% to 37% (Metcalf and Eddy
2014), with the average of 34% used in this study.
E-2
-------
SEPA
United States
Environmental Protection
Agency
National Center for Environmental Assessment
Office of Research and Development
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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