IDENTIFYING COST SAVINGS THROUGH ENERGY CONSERVATION MEASURES IN
MECHANICALLY AERATED ACTIVATED SLUDGE TREATMENT PROCESSES IN SOUTHEAST
FLORIDA
by
Eric Stanley
A Thesis Submitted to the Faculty of
The College of Engineering and Computer Science
in Partial Fulfillment of the Requirements for the Degree of
Master of Science
Florida Atlantic University
Boca Raton, FL
May 2012
IDENTIFYING COST SAVINGS THROUGH ENERGY CONSERVATION l\ffiASURES IN
l\ffiCHANICALLY AERATED ACTIVATED SLUDGE TREATMENT PROCESSES IN SOUTHEAST
FLORIDA
By
Eric Stanley
This thesis was prepared under the direction of the candidate's thesis advisor, Dr. Frederick Bloetscher,Department of Civil, Environmental, and Geomatics Engineering" and.has been approved by the membersof his supervisory committee. It was submitted to the faculty of the College of Engineering and ComputerScience and was accepted in partial fulfillment of the requirements for the degree of Master of Science.
SUPERVISORY COMMITTEE:
,Ph.D.
...._;:J-C-
eoerickBloetscher, Ph.D., P.E.Thesis Advi r
Panagiotis D. Scaralatos, Ph.D..Chair, Departmentof Civil, Environmeniii ,and Geomatics Engineering
Mohammad Ilyas, Ph.D.Interim Dean, College of Engineeringand Computer Science
Barry T. R son, Ph.D.Dean, Graduate College
b·l/~/ 'UJ1'2.Date ..
ii
iii
ABSTRACT
Author: Eric Stanley
Title: Identifying Cost Savings through Energy Conservation Measures in Mechanically Aerated Activated Sludge Treatment Processes in Southeast Florida
Institution: Florida Atlantic University
Thesis Advisor: Dr. Frederick Bloetscher
Degree: Master of Science
Year: 2012
This thesis presents a model which estimates energy and cost savings that can be realized by
implementing Energy Conservation Measures (ECMs) at mechanically aerated wastewater treatment plants
(WWTPs) in southeast Florida. Historical plant monitoring data is used to estimate savings achieved by
implementing innovative aeration technologies which include; 1) Fine Bubble Diffusers; 2) Single-Stage
Turbo Blowers; 3) Automatic Dissolved Oxygen (DO) Control. Key assumptions for modeling
performance of each technology are researched and discussed, such as trends in the future cost of
electricity, efficiency of blowers, and practical average DO levels for each scenario. Capital cost estimates
and operation and maintenance (O&M) costs are estimated to complete life-cycle cost and payback
analyses. The benefits are quantified on an individual and cumulative basis, to identify which technologies
are cost-beneficial. The results demonstrate that levels of payback of 20 years or less are available at the
three WWTPs studied.
iv
ACKNOWLEDGEMENTS
The author wishes to thank his wife, Tatyana, without whose love and support nothing would be
possible. The author also wishes to thank his employer, Hazen and Sawyer, P.C., including senior engineers
and coworkers, for providing a dynamic workplace environment supportive of furthering understanding of
complex engineering issues. The help of the utilities officials including Norm Wellings, Gabe Destio, and
Ed Catalano with the City of Boca Raton, and Chuck Flynn with the City of Plantation, was instrumental in
furthering the progress of this work. Lastly, the author would like to thank his thesis committee, including
Frederick Bloetscher, Ph.D., P.E., and Daniel Meerof, Ph.D, for their guidance in completing this thesis.
v
IDENTIFYING COST SAVINGS THROUGH ENERGY CONSERVATION MEASURES IN
MECHANICALLY AERATED ACTIVATED SLUDGE TREATMENT PROCESSES IN SOUTHEAST
FLORIDA
LIST OF TABLES .........................................................................................................................................ix
LIST OF FIGURES ..................................................................................................................................... xiii
I. INTRODUCTION ....................................................................................................................................... 1
1.1 Overview of the Aeration Process ................................................................................................. 3
1.2 Less Efficient Mechanical Aeration Versus More Efficient Fine-Bubble Diffused Aeration ........ 5
1.3 Less Efficient Multi-stage Centrifugal Blowers Versus More Efficient Single-stage Turbo Blowers ....................................................................................................................................................... 6
1.4 Less Efficient Manual DO Control Versus More Efficient Automatic DO Control ...................... 7
1.5 Combining Technologies to Optimize Efficiency ........................................................................ 10
1.6 Summary of Facilities Studied ..................................................................................................... 11
II - LITERATURE REVIEW – DISCUSSION OF THE STATE OF THE ART IN ACTIVATED SLUDGE PROCESS CONTROL AND KEY MODELING ASSUMPTIONS ............................................ 13
2.1 Energy Conservation Measure Case Studies ................................................................................ 13
2.2 Fine Bubble Diffusers .................................................................................................................. 17
2.3 Blower Technology ...................................................................................................................... 18
2.4 DO Control Strategy ................................................................................................................... 23
2.4.1 Manual Control ........................................................................................................................ 23
2.4.2 Automatic DO Control ............................................................................................................. 24
2.4.3 DO Probes ................................................................................................................................ 25
2.4.4 Modulating Valves ................................................................................................................... 25
2.4.5 Flow Meters ............................................................................................................................. 26
2.5 Piping ........................................................................................................................................... 27
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2.6 Summary of Technologies ........................................................................................................... 27
2.7 Key Assumptions For Aeration Model ........................................................................................ 28
2.7.1 DO Levels ................................................................................................................................ 28
2.7.2 Blower Efficiency Assumptions .............................................................................................. 30
2.7.3 Flowrate Assumptions ............................................................................................................. 30
2.7.4 Aeration Modeling Global Assumptions ................................................................................. 31
III. LITERATURE REVIEW – COST ESTIMATING METHODS AND ASSUMPTIONS ...................... 33
3.1 Cost Estimate Level of Accuracy ................................................................................................ 33
3.2 Life Cycle Cost Analysis Method And Assumptions .................................................................. 35
3.3 Capital Cost ................................................................................................................................. 41
3.3.1 Cost of Blower Technology ..................................................................................................... 42
3.3.2 Cost of Fine Bubble Diffused Aeration Technology ............................................................... 43
3.3.3 Foregone Capital Replacement Costs and Salvage Value ........................................................ 43
3.4 Operation and Maintenance Costs ............................................................................................... 44
IV. METHODOLOGY .................................................................................................................................. 46
4.1 Identifying Specific Energy Conservation Measures .................................................................. 46
4.2 Lifecycle Cost Analysis of ECMs ................................................................................................ 46
4.2.1 Historical Plant Data ................................................................................................................ 49
4.2.2 Estimating Yield ...................................................................................................................... 50
4.2.3 Project Future Flows and Loadings ......................................................................................... 52
4.2.4 Calculate Oxygen Requirement and Required Air Flowrates .................................................. 53
4.2.5 Size Process Air Piping ............................................................................................................ 66
4.2.6 Estimate Headloss Through Pipes and Create System Curve .................................................. 68
4.2.7 Size Blowers ............................................................................................................................ 73
4.2.8 Estimate Capital Cost ............................................................................................................... 77
4.2.9 Estimate O&M and Foregone Capital Replacement Costs ...................................................... 78
4.2.10 Energy Baseline – Estimated Energy Consumption of Existing Mechanical Aerators ............ 79
vii
4.2.11 Complete Life Cycle Cost Analysis ......................................................................................... 81
4.2.12 Model Accuracy Verification................................................................................................... 86
V. PLANT ECM ASSESSMENT ................................................................................................................. 93
5.1 City of Boca Raton WWTP ......................................................................................................... 93
5.1.1 Boca Raton WWTP - Existing Secondary Treatment .............................................................. 93
5.1.2 Boca Raton WWTP –Influent and Effluent Water Quality ...................................................... 95
5.1.3 Boca Raton WWTP – Proposed ECM Design ......................................................................... 96
5.1.4 Boca Raton WWTP - Results and Discussion ......................................................................... 97
5.1.5 Boca Raton WWTP - Sensitivity Analysis ............................................................................ 101
5.2 Broward County North Regional WWTP .................................................................................. 102
5.2.1 Broward County North Regional WWTP - Existing Secondary Treatment .......................... 102
5.2.2 Broward County North Regional WWTP –Influent and Effluent Water Quality .................. 103
5.2.3 Broward County North Regional WWTP – Plant Specific Methodology Considerations .................................................................................................................................... 104
5.2.4 Broward County North Regional WWTP – Proposed ECM Design ..................................... 106
5.2.5 Broward County North Regional WWTP – Results and Discussion ..................................... 107
5.2.6 Broward County North Regional WWTP - Sensitivity Analysis ........................................... 112
5.3 Plantation Regional WWTP ...................................................................................................... 113
5.3.1 Plantation Regional WWTP - Existing Secondary Treatment .............................................. 113
5.3.2 Plantation Regional WWTP – Influent and Effluent Water Quality ...................................... 113
5.3.3 Plantation Regional WWTP – Proposed ECM Design .......................................................... 115
5.3.4 Plantation Regional WWTP – Results and Discussion ......................................................... 115
5.3.5 Plantation Regional WWTP - Sensitivity Analysis ............................................................... 119
VI. DISCUSSION AND COMPARISON OF RESULTS .......................................................................... 121
6.1 Improvement of Efficiency Comparison and Analysis .............................................................. 121
6.2 Capital Cost Comparison and Analysis .................................................................................... 125
6.3 Payback Comparison and Analysis ............................................................................................ 128
viii
6.4 Sensitivity Analysis Comparison ............................................................................................... 132
6.5 Total Savings And Regional Savings ......................................................................................... 136
6.6 Current Energy Intensity Discrepancy and Potential Operational Modifications at Plantation Regional WWTP .................................................................................................................... 136
6.7 Ocean Outfall Rule Compliance ................................................................................................ 142
6.8 Greenhouse Gas Emissions ........................................................................................................ 144
VII. CONCLUSIONS AND RECOMMENDATIONS .............................................................................. 146
7.1 Conclusions ................................................................................................................................ 146
7.2 Recommendations ...................................................................................................................... 151
APPENDICES ............................................................................................... Error! Bookmark not defined.
BIBILIOGRAPHY ...................................................................................................................................... 268
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LIST OF TABLES
Table 1.1 – Study Facility Summary ............................................................................................................. 12
Table 2.1 – General ECM Case Study Survey .............................................................................................. 14
Table 2.2 - Fine Bubble Diffuser Technologies with Highest SOTE’s ......................................................... 18
Table 2.3 – Blower Technology Comparison ................................................................................................ 23
Table 2.4 – Summary of Technologies .......................................................................................................... 28
Table 2.5 – Manual DO Control - Case Study DO Levels ............................................................................ 29
Table 2.6 – Automatic DO Control – Case Study DO Levels ....................................................................... 30
Table 3.1 - AACE Estimate Class Level Characteristics (Christensen, 2005) .............................................. 34
Table 3.2 – 2006 – 2011 AEO Report Average Predicted US Electricity Annual Real Inflation Rates .............................................................................................................................................................. 39
Table 3.3 – 2011 AEO Report Base and Side Case Assumptions ................................................................. 39
Table 3.4 – Cost of Blower Technologies ..................................................................................................... 42
Table 3.5 – Cost of Fine Bubble Diffusers .................................................................................................... 43
Table 3.6 – Major Equipment Requiring Eventual Replacement .................................................................. 44
Table 3.7 – Major Equipment Requiring Eventual Replacement .................................................................. 45
Table 4.1 – Summary of Methodology .......................................................................................................... 48
Table 4.2 – Boca Raton WWTP– Incremental Life-Cycle Cost Analysis ..................................................... 52
Table 4.3 – Key Assumptions for ECMs ....................................................................................................... 57
Table 4.4 – Extreme Weather Design Conditions ......................................................................................... 74
Table 4.5 – Power Factor .............................................................................................................................. 80
Table 4.6 – Predicted SCFM vs. Standard Oxygen Requirement based on Loading .................................... 90
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Table 4.7 – Model Verification Sensitivity Analysis .................................................................................... 90
Table 4.8 – Mechanically Aerated Module A, B, vs. Fine Bubble Aerated Module C Measured Energy Usage Comparison ............................................................................................................................ 91
Table 4.9 – Model Efficiency Gain Prediction Vs. Actual Efficiency Gain Prediction ................................ 92
Table 5.1 – Study Facility Summary ............................................................................................................. 93
Table 5.2 - Aeration Basin Characteristics .................................................................................................... 94
Table 5.3 - Mechanical Aeration Characteristics .......................................................................................... 94
Table 5.4 - Diffused Aeration Characteristics ............................................................................................... 94
Table 5.5 - Blower Characteristics ................................................................................................................ 95
Table 5.6 – Boca Raton WWTP – Design Influent/Effluent Based on 2007-2009 Flow/Loading Data ............................................................................................................................................................... 95
Table 5.7 – Boca Raton WWTP – Design Influent/Effluent Adjusted to Est. 2011-2031 Avg Flowrate ......................................................................................................................................................... 96
Table 5.8 – Boca Raton WWTP – Design Influent/Effluent Adjusted to Design Flow ................................ 96
Table 5.9 – Life Cycle Cost Analyses Estimated Costs ................................................................................ 97
Table 5.10 – Life Cycle Cost Analyses Estimated Savings ........................................................................... 97
Table 5.11 – Boca Raton WWTP– Incremental Life-Cycle Cost Analysis ................................................... 99
Table 5.12 – Boca Raton WWTP – Payback Sensitivity Analysis .............................................................. 101
Table 5.13 - Aeration Basin Characteristics – Modules A and B ................................................................ 103
Table 5.14 - Mechanical Aeration Characteristics – Modules A and B ...................................................... 103
Table 5.15 – Broward Co. N. Regional WWTP – Design Influent/Effluent Based on 2004-2006 ............. 104
Table 5.16 – Broward Co. N. Regional WWTP – Design Influent/Effluent Adjusted to Est. 2011- 2031 Avg Flow ............................................................................................................................................ 104
Table 5.17 – Broward Co. N. Regional WWTP – Design Influent/Effluent Adjusted to Design Flow ............................................................................................................................................................ 104
Table 5.18 – 2004-2006 # of Basins In Service vs. Flowrate ...................................................................... 105
Table 5.19 – Projected Module D Energy Reduction .................................................................................. 106
Table 5.20 – Life Cycle Cost Analyses Estimated Costs ............................................................................ 107
Table 5.21 – Life Cycle Cost Analyses Estimated Savings ......................................................................... 108
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Table 5.22 – Broward Co. N. Regional WWTP – Incremental Life-Cycle Cost Analysis .......................... 110
Table 5.23 – Broward Co. N. Regional WWTP – Payback Sensitivity Analysis ........................................ 112
Table 5.24 - Aeration Basin Characteristics ................................................................................................ 113
Table 5.25 - Mechanical Aeration Characteristics ...................................................................................... 113
Table 5.26 – Plantation Regional WWTP – Design Influent/Effluent Based on 2007-2009 Flow/ Loading Data ............................................................................................................................................... 114
Table 5.27 – Plantation Regional WWTP – Design Influent/Effluent Adjusted to Est. 2011-2031 Avg Flow ..................................................................................................................................................... 114
Table 5.28 – Plantation Regional WWTP – Design Influent/Effluent Adjusted to Design Flow ................ 114
Table 5.29 – Life Cycle Cost Analyses Estimated Costs ............................................................................ 116
Table 5.30 – Life Cycle Cost Analyses Estimated Savings ......................................................................... 116
Table 5.31 – Plantation Regional WWTP – Incremental Life-Cycle Cost Analysis ................................... 118
Table 5.32 – Plantation Regional WWTP – Payback Sensitivity Analysis ................................................. 119
Table 6.1 – Percent Efficiency Gain Per Plant and Scenario ....................................................................... 121
Table 6.2 – Payback Per Plant and Scenario ............................................................................................... 121
Table 6.3 – Cumulative Capital Cost Per ECM ........................................................................................... 126
Table 6.4 – Sensitivity Analysis Comparison ............................................................................................. 134
Table. 6.5 – Projected Energy Savings Related To Implementation of ECMs ............................................ 136
Table 6.6 – Current Aeration Energy Intensity Comparison ....................................................................... 136
Table 6.7 – Average Mechanical Aerator Energy Use Comparison ............................................................ 137
Table 6.8 – Average Power Supplied Per Zone ........................................................................................... 138
Table 6.9 – Current Oxygen Supplied vs. Oxygen Required ...................................................................... 139
Table 6.10 – Plantation Operational Modification - Energy Intensity Comparison .................................... 140
Table 6.11 – Plantation Operational Modification - Current Oxygen Supplied vs. Oxygen Required ....... 141
Table 6.12 – Plantation Operational Modification –Energy Savings Resulting From ECM Implementation Following Operational Modification ................................................................................. 141
Table 6.13 – Plantation Operational Modification – Payback Resulting From ECM Implementation Following Operational Modification ........................................................................................................... 142
xii
Table 6.14 – Greenhouse Gas Prevention Equivalency For Three Facilities Studied ................................. 144
Table 7.1 – Life Cycle Cost Analysis Assumptions .................................................................................... 146
Table 7.2 – Life Cycle Cost Analyses Estimated Costs .............................................................................. 146
Table 7.3 – Life Cycle Cost Analyses Estimated Savings ........................................................................... 147
Table 7.4 – Life Cycle Cost Analyses Estimated Median Paybacks ........................................................... 147
xiii
LIST OF FIGURES
Figure 1.1 – Typical Electricity Requirements at Activated Sludge Treatment Processes in the US .............. 1
Figure 1.2 – Typical Activated Sludge Treatment Process With Aeration ...................................................... 4
Figure 1.3 – Aerial Photograph - City of Boca Raton Activated Sludge Treatment Process (Photo by Google Earth) .................................................................................................................................................. 4
Figure 1.4 – Surface Mechanical Aerator – Plantation Regional WWTP ....................................................... 5
Figure 1.5 – Fine Bubble Diffuser (Photo by ITT Water and Wastewater – Sanitaire) .................................. 6
Figure 1.6 – Multi-Stage Centrifugal Blower and Turbo Blower .................................................................... 7
Figure 1.7 – Manual vs. Automatic DO Control ............................................................................................. 8
Figure 1.8 – Automatic DO Controller (Photo by Hach Company) ................................................................ 9
Figure 1.9 – Automatic DO Control System ................................................................................................... 9
Figure 1.10 – Existing Aeration Basin and Proposed ECM Nos. 1 through 3............................................... 11
Figure 2.1 – Positive Displacement Blower Cross-Section (Photo by Aerzen USA Corporation) ............... 19
Figure 2.2 – Dual Guide Vane Control Blower Cross-Section (Graphic by Siemens, Inc.) .......................... 20
Figure 2.3 – Multi-Stage Centrifugal Blower Cross-Section (Graphic by Gardner Denver, Inc.) ................ 21
Figure 2.4 – Turbo Blower (Dual) Cross-Section (Graphic by APG Neuros) ............................................... 22
Figure 2.5 – Typical Flow Meters for Measuring Air Flowrates ................................................................... 26
Figure 2.6 – Temperature vs. Tau ................................................................................................................. 32
Figure 3.1 –2011 - 2035 AEO Report Predicted US Electricity Real Rates .................................................. 38
Figure 3.2 – 2006 – 2011 AEO Report Predicted US Electricity Annual Real Inflation Rates ..................... 39
Figure 4.1 – Spreadsheet 1. 1 – Influent-Effluent Specifier .......................................................................... 49
xiv
Figure 4.2 – Typical Yield for Primarily Treated Domestic Wastewater (Tchobanoglous et al., 2003) ....... 51
Figure 4.3 – Typical Yield for Raw Domestic Wastewater (Tchobanoglous et al., 2003) ............................ 51
Figure 4.4 – Spreadsheet 1. 2 – Flow Projection ........................................................................................... 53
Figure 4.5 – Sanitaire Silver Series II - SOTE Vs. SCFM per diffuser ........................................................ 58
Figure 4.6 – Spreadsheet 2.0 – Aeration Calculations – Global Parameters ................................................. 59
Figure 4.7 – Spreadsheet 2.1 – Aeration Calculations – Diffusers ................................................................ 63
Figure 4.8 – Spreadsheet 2.2 – Aeration Calculations – Turbo Blowers ....................................................... 64
Figure 4.9 – Spreadsheet 2.3 – Aeration Calculations – DO Control ............................................................ 65
Figure 4.10 – Spreadsheet 3.1 – System Design – Size Pipes ....................................................................... 68
Figure 4.11 – Spreadsheet 3.2 – System Design – Estimate Losses Through Pipes ..................................... 72
Figure 4.12 – Spreadsheet 3.3 – System Design – System Curve ................................................................. 73
Figure 4.13 – Spreadsheet 3.4 – System Design – Blower Design ............................................................... 77
Figure 4.14 – Spreadsheet 4.0 – Cost Estimate - Summary .......................................................................... 78
Figure 4.15 – Spreadsheet 5.0 – O&M Costs ................................................................................................ 79
Figure 4.16 – Spreadsheet 6.0 – Lifecycle Cost Analysis Inputs .................................................................. 81
Figure 4.17 – Spreadsheet 6.1.1 – Life Cycle Cost Analysis ........................................................................ 84
Figure 4.18 – Spreadsheet 6.2 – Incremental Life Cycle Cost Analysis Summary ....................................... 85
Figure 4.19 – Model Verification - Week of August 8, 2010 ........................................................................ 88
Figure 4.20 – Predicted SCFM vs. Measured SCFM .................................................................................... 89
Figure 5.1 – Present Value Comparison of Existing Process Versus Proposed ECMs ................................. 98
Figure 5.2 – Boca Raton WWTP – Incremental Increase in Efficiency Per ECM ...................................... 100
Figure 5.3 – Present Value Comparison of Existing Process Versus Proposed ECMs ............................... 109
Figure 5.4 – Present Value Comparison of Existing Process Versus Proposed ECMs – No Consideration for Module D Effects ........................................................................................................... 109
Figure 5.5 – Broward Co. N. Regional WWTP – Incremental Increase in Efficiency Per ECM ................ 111
Figure 5.6 – Present Value Comparison of Existing Process Versus Proposed ECMs ............................... 117
Figure 5.7 – Plantation Regional WWTP – Incremental Increase in Efficiency Per ECM ......................... 118
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Figure 6.1 – Improvement of Efficiency Per Scenario– kWh / lb BOD Treated ......................................... 122
Figure 6.2 – Improvement of Efficiency Per Scenario– kWh / SOR ........................................................... 122
Figure 6.3 – Improvement of Efficiency Per Scenario– kWh / MGD Treated ............................................ 123
Figure 6.4 – Improvement of Efficiency Per Scenario– kWh / SOR - (not considering Broward County North Regional WWTP Module D Assumptions) .......................................................................... 124
Figure 6.5 – Range of Capital Cost / MGD Treated .................................................................................... 126
Figure 6.6 – Range of Capital Cost / lb CBOD5 Treated ............................................................................ 127
Figure 6.7 – Range of Capital Cost / SOR .................................................................................................. 127
Figure 6.8 – ECM No. 1 - Fine Bubble Diffuser Payback Comparison ...................................................... 128
Figure 6.9 – ECM No. 2 - Turbo Blower Payback Comparison ................................................................. 129
Figure 6.10 – ECM No. 3 - DO Control Payback Comparison ................................................................... 130
Figure 6.11 – ECM No. 1 through 3 - Cumulative Payback Comparison ................................................... 131
Figure 6.12 – Sensitivity Analysis – Results of Variation in CPI Inflation or Bond Rate Assumptions (Boca Raton WWTP Example) ................................................................................................................... 135
Figure 6.13 – Sensitivity Analysis – Results of Variation in Electricity Price (Boca Raton WWTP Example) ..................................................................................................................................................... 135
Figure 7.1 – Average Contribution of Each ECM to Overall Total Energy Savings ................................... 149
1
I. INTRODUCTION
Electricity comprises a significant and rising portion of operating costs for municipal wastewater
utilities in the United States. Approximately 3 percent of energy consumed in the United States is by water
and wastewater treatment plants (WWTPs) (Krause et al., 2010). Seventy percent of WWTPs in the United
States exceeding 2.5 million gallons per day (MGD) utilize activated sludge secondary treatment, where 45
to 75 percent of electricity use is consumed in the aeration process (Rosso and Stenstrom, 2006). Because
the aeration treatment process consumes the majority of energy in WWTPs utilizing secondary treatment,
improving the efficiency of aeration can result in the largest cost and energy savings to utilities in southeast
Florida, nationwide and beyond. Figure 1.1 demonstrates the typical energy usage at wastewater treatment
facilities in the United States utilizing the activated sludge treatment process.
Aeration54.1%
Clarifiers3.2%
Grit1.4%
Screens0.0%
Pumping14.3%
Lighting &Buildings8.1%
Chlorination0.3%
Belt Press3.9%
Anaerobic Digestion14.2%
Gravity Thickening0.1%
Return Sludge Pumping0.5%
(SAIC, 2006)
Figure 1.1 – Typical Electricity Requirements at Activated Sludge Treatment Processes in the US
2
Within the southeast Florida region, the effects of the energy-consuming aeration process are also
apparent. For example, the Broward County North Regional WWTP utilizes secondary treatment and is the
largest single electricity user in Broward County consuming approximately 133,000 KW. The aeration
basins comprise approximately half of this power demand (Bloetscher, 2011).
The state-of-the-art for energy efficient wastewater treatment aeration technology continues to
advance. However, improved air diffusers, blowers, and automated control systems have not yet been
adopted by many WWTPs that could benefit from them. Treatment plants continue to delay modernizing
their aeration systems for various reasons. Joseph Cantwell with the Wisconsin Focus on Energy indicates
that this may be because plant operators typically focus on meeting effluent quality requirements and
keeping operating costs in accordance with expectations and not energy efficiency. Similarly, capital
expenditures are driven by the need to increase capacity and comply with permit requirements (Jones et al.,
2007). .
This thesis presents a model developed to estimate the energy savings and resulting cost savings
that can be realized by implementing Energy Conservation Measures (ECMs) at conventional activated
sludge WWTPs, focusing on three facilities in southeast Florida; the City of Boca Raton WWTP (WWTP),
the Broward County North Regional WWTP, and the Plantation Regional WWTP. A model is developed
and presented which uses historical plant monitoring data to estimate the energy and cost savings achieved
by implementing innovative aeration technologies, which include; ECM No. 1 - fine bubble diffusers; ECM
No. 2 - single-stage turbo blowers; and ECM No. 3 - automatic dissolved oxygen (DO) control. Many key
assumptions for modeling the performance of each technology were researched, such as predicted trends in
the future cost of electricity, practical values to assume for efficiency of fine bubble diffuser or single-stage
turbo blower performance, and average DO level used for automatic DO control. The model was verified
to demonstrate reasonable accuracy using actual side by side efficiency data for mechanical aeration and
fine bubble diffused aeration.
A preliminary construction plan for implementing each ECM is designed and used for developing
a feasibility-level capital cost estimate. Operation and maintenance (O&M) costs for implementing each
technology are also estimated. The capital cost estimate is then compared with the net present value of
estimated energy savings and O&M costs to estimate the net present value life-cycle cost evaluation and
3
payback period. The net present value of implementing each technology is quantified on an individual and
cumulative basis, to identify the cost-effectiveness of each technology. The goal of the model is to provide
a tool to evaluate the cost-effectiveness of implementing ECMs within a reasonable level of effort.
1.1 Overview of the Aeration Process
The main purpose of aeration in conventional wastewater treatment processes is to stimulate
bacteria and protozoa to consume the organic material in wastewater. In the presence of oxygen, various
strains of bacteria incorporate organic matter into their biomass, replicate, and produce extracellular
polymers that result in the formation of biological flocs. Flocs are bodies made up of multiple bacterial
colonies that are heavier and have less surface area than the sum of their parts. Some of the organic
material is completely metabolized into simple end products such as carbon dioxide and water
(Tchobanoglous et al., 2003), but the majority remains solid material. Once exiting the aeration process, the
flocculated bacterial and organic matter enter the secondary clarification process which brings flow to a
relatively quiescent state, where most of the heavier flocs are able to settle out of the wastewater by gravity
and settle into a thickened sludge at the bottom of the tank, while the clarified effluent water overflows the
top of the tank and flows downstream where it is further treated. A majority of the sludge containing
bacterial and protozoan biomass is then pumped back to the beginning of the aeration process to “seed” the
incoming flow as return activated sludge (RAS), and a smaller portion of the sludge is wasted as waste
activated sludge (WAS) to downstream solids treatment processes where it is ultimately disposed of.
Figure 1.2 provides an overview of a typical activated sludge treatment process with aeration. An aerial
photograph of the activated sludge treatment process at the City of Boca Raton WWTP is provided as
Figure 1.3 as an example.
4
Figure 1.2 – Typical Activated Sludge Treatment Process with Aeration
Figure 1.3 – Aerial Photograph - City of Boca Raton Activated Sludge Treatment Process (Photo by Google Earth)
Bacteria and protozoa incorporate organic matter into their biomass and form
flocs in the presence of oxygen
Aeration Basin No. 1
Aeration Basin No. 2
Aeration Basin No. 3
Clarifier No. 1
Clarifier No. 2
Wastewater with suspended organic matter enters the
aeration basin
Wastewater is brought to standstill in clarifier tank where flocs settle
out as sludge
Clarifier effluent spills over the top of clarifier
tank for further treatment downstream
A portion of biomass is returned to the beginning of the aeration basin
to seed the incoming flow as RAS
A portion of the biomass wasted to downstream solids treatment
processes as WAS
5
1.2 Less Efficient Mechanical Aeration Versus More Efficient Fine-Bubble Diffused Aeration
The two most common methods of providing oxygen to wastewater in the aeration basin are
mechanical aeration or diffused aeration systems. Mechanical aeration is provided by large impellers that
are submerged in the wastewater and rotated using high capacity electric motors which consume a large
amount of electricity. For example, the Broward County North Regional WWTP utilizes twenty four 100
horsepower (hp) aerators in their module A and module B aeration basins, for a total nameplate power draw
of 2,400 hp. The mechanical aerator impellers agitate the wastewater so that it is splashed into the air at
the water surface, which increases the rate of transfer of oxygen from the atmosphere into the aqueous
phase. The three plants investigated in this study; the City of Boca Raton WWTP, Broward County North
Regional WWTP, and Plantation Regional WWTP, each utilize mechanical aeration. A view of one of the
mechanical aerators at the Plantation Regional WWTP is provided as Figure 1.4.
Figure 1.4 – Surface Mechanical Aerator – Plantation Regional WWTP
It has been well established that diffused air systems, specifically fine bubble diffused air systems,
are much more efficient at oxygen transfer than mechanical aeration (Shammas et al., 2007). The small
bubble size produced by fine bubble diffusers has a high surface area to volume ratio, which allows much
higher oxygen transfer efficiency compared to mechanical aeration. Thus, implementing fine bubble
6
diffused aeration at the treatment plants currently utilizing mechanical aeration will lead to cost and energy
savings. Fine bubble diffusers are referred to throughout this paper as ECM No. 1. A view of a fine
bubble diffuser is provided as Figure 1.5 below.
Figure 1.5 – Fine Bubble Diffuser (Photo by ITT Water and Wastewater – Sanitaire)
1.3 Less Efficient Multi-stage Centrifugal Blowers versus More Efficient Single-stage Turbo Blowers
For diffused air systems, it is necessary to provide a high volume of relatively high pressure air to
the diffusers. A blower is a compressor that is operated by a high-capacity electric motor which supplies
high-volume, high-pressure air to the activated sludge treatment process. In recent history the most
common blower technology for supplying air at WWTPs has been the multi-stage centrifugal blower,
which is a blower where multiple impellers are mounted on a common rotor shaft. More recently, a new
blower technology has come into use known as turbo blowers, which comprises a high-efficiency single
impeller direct-driven by a high-speed permanent magnet motor and variable frequency drive (VFD) to
achieve speed and airflow turndown. The first turbo blower units in North America were installed in 2004
(Rohrbacher et al., 2010). The combination of the high efficiency impeller and VFD capability combine to
provide efficiencies of approximately 10 to 15 percent greater than a comparable multi-stage centrifugal
blower (Rohrbacher et al., 2010). Thus, implementing turbo blowers instead of the typical multi-stage
centrifugal blowers at the treatment plants currently utilizing mechanical aeration could lead to cost and
7
energy savings. Turbo blowers are referred to throughout this paper as ECM No. 2. Figure 1.6 provides
a view of a multi-stage centrifugal blower and a turbo blower.
Multi-Stage Centrifugal Blower (Photo by HSI, Inc.) Turbo Blower (Photo by Gray and Osborne, Inc.)
Figure 1.6 – Multi-Stage Centrifugal Blower and Turbo Blower
1.4 Less Efficient Manual DO Control Versus More Efficient Automatic DO Control
Another way that WWTPs can save energy is by optimizing the amount of air that is supplied to
the aeration basins, by continuously varying the amount of air supplied based on the amount of oxygen
required by the treatment process. It is common for WWTPs to control the amount of air supplied based on
DO level, where most plants attempt to maintain a DO level of 1 to 3 mg/L in aeration basins. The most
common, yet inefficient method to control DO is the manual DO control strategy, where operators take one
or more manual readings of DO throughout the day. DO is typically measured with a handheld meter or in-
situ meter, and then a corresponding airflow rate to meet the required DO. The manual control method is
lacks accuracy and is most likely to result in excessive electricity costs, because operators must
conservatively set the airflow to a high setting that will meet the maximum oxygen demand during the time
of day where the peak wastewater loading occurs.
The alternative is the automatic DO control strategy, which utilizes DO sensors that are
permanently submerged in the wastewater of the aeration basins and continuously take readings and
“feedback” signals to a controller. The controller then automatically adjusts airflow to maintain a
predetermined DO set point (typically 1 to 3 mg/L) by continuously adjusting the blowers and/or motor-
8
operated air distribution control valves to each basin. The automatic DO control feedback strategy greatly
reduces electricity costs when compared to manual DO control by preventing overaeration. Recent
advances in DO probe technology within the past 10 years have increased the reliability of using automatic
DO control. Figure 1.7 shows a typical DO response curve plotted against the DO level of an aeration
basin with and without automatic DO control. The figure demonstrates how manual DO control results in
excessive aeration at most times during the day except for the time of peak oxygen demand, compared to
automatic DO control which maintains a constant low DO level which results in energy savings.
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
0
200
400
600
800
1,000
1,200
1,400
1,600
0:00 4:00 8:00 12:00 16:00 20:00
DO Sup
plied (m
g/L)
Oxygen Dem
and (lb
/hr)
Time of Day
Oxygen Demand (lb/hr)
DO supplied (manual control) (mg/L)
DO supplied (auto control) (mg/L)
0:00
Manual DO control ‐ excessive DO is supplied throughout the day except for time of peak oxygen demand
Automatic DO control ‐ DO is maintained at predetermined setpoint, preventing wastedenergy by supplying excessive air
Figure 1.7 – Manual vs. Automatic DO Control
A view of a typical DO controller and DO probe is shown in Figure 1.8. Automatic DO control
strategy is referred to throughout this paper as ECM No. 3. The automatic DO control system installed
alongside the aeration basins at the Jacksonville Electrical Authority (JEA) – Arlington East Water
Reclamation facility in Jacksonville, Florida is provided as Figure 1.9 for example.
9
Figure 1.8 – Automatic DO Controller (Photo by Hach Company)
Figure 1.9 – Automatic DO Control System
DO probe - probe is permanently submerged in wastewater, and provides signal to DO controller
DO controller – controller processes signal from probe, and sends signal to motor operated valve to open/close, or blower to increase/decrease airflow
10
1.5 Combining Technologies to Optimize Efficiency
In the previous sections, three ECMs were discussed that can be employed at WWTPs; ECM No.
1 - fine bubble diffusers; ECM No. 2 - single-stage turbo blowers; and ECM No. 3 - automatic DO control.
By combining the three ECMs, energy efficiency can be maximized. It will be shown in this paper that fine
bubble diffusers potentially account for an approximate 20 percent increase in efficiency in the aeration
process, single-stage turbo blowers potentially account for a 10 percent increase in efficiency, and
automatic DO control accounts for an approximate 20 percent increase in efficiency. The combination of
all three technologies can potentially result in a total potential increase in energy efficiency of
approximately 50 percent within the aeration process. Case studies for making similar improvements to
aeration basins have shown increases in efficiency as high as 77% (Peters et al., 2008).
A model was developed and presented which uses historical plant monitoring data to estimate the
energy and cost savings achieved by implementing the innovative aeration technologies discussed above.
Capital costs, O&M costs, and energy savings are estimated and a life cycle cost analysis is completed for
the following options.
• Base case – implement no ECMs, continue operating with mechanical aeration
• ECM No. 1 – fine bubble diffusers
• ECM No. 1 – fine bubble diffusers, and ECM No. 2 – single-stage turbo blowers
• ECM No. 1 – fine bubble diffusers, ECM No. 2 – single stage turbo blowers, and ECM No. 3 –
automatic DO control
Figure 1.10 illustrates the proposed ECMs for each option:
11
Aeration Basin
Surface mechanical aerators
Existing system ECM No. 1 - fine bubble diffusers
Aeration Basin
Aeration Basin
ECM No. 2 – turbo blowers
Aeration Basin
ECM No. 3 – automatic DO control system
Figure 1.10 – Existing Aeration Basin and Proposed ECM Nos. 1 through 3
1.6 Summary of Facilities Studied
The model developed to estimate the energy savings and resulting cost savings by implementing
ECMs was applied to the plants shown in Table 1.1. These facilities are the only three plants in the
Southeast Florida region that currently utilize mechanically aerated conventional activated sludge treatment
processes.
12
Table 1.1 – Study Facility Summary
PLANT NAME CITY AERATION SYSTEM SUMMARY
Boca Raton WWTP Boca Raton, FL
17.5 MGD capacity plant, (3) 2.1 MG aeration basins each with (3)
100-hp mechanical surface aerators. (3) multi-stage centrifugal
blowers provide peak season / high loading supplemental aeration.
Broward County
North Regional
WWTP
Pompano
Beach, FL
95 MGD capacity plant with both mechanical and fine bubble
diffused aeration. Study focuses on (8) 2.2 MG aeration basins
each with (3) 100-hp mechanical surface aerators.
Plantation Regional
WWTP Plantation, FL
18.9 MGD capacity plant with (3) 1.1 MG aeration basins each with
(1) 125-hp and (2) 100-hp mechanical surface aerators.
13
II - LITERATURE REVIEW – DISCUSSION OF THE STATE OF THE ART IN ACTIVATED
SLUDGE PROCESS CONTROL AND KEY MODELING ASSUMPTIONS
2.1 Energy Conservation Measure Case Studies
ECMs implemented by various municipalities have been presented and documented at the Water
Environment Federation Technical Exhibition and Conferences (WEFTEC) and are presented to provide an
approximate range of energy savings actually achieved at plants implementing ECMs similar to those in
this study. The scope of information and methodology for each case varies too widely to make scientific
comparisons. For example, capital costs are given for some projects but not for others, capital costs that are
given for ECMs are not isolated from other non-ECM related improvements, and methodology for
measuring energy savings varies. However, a general survey of the ECM’s implemented and resulting
energy savings is provided for demonstrative purposes in Table 2.1.
14
Table 2.1 – General ECM Case Study Survey
Plant
AD
F (M
GD
)
Fine
B
ubbl
e D
iffus
ers
Turb
o B
low
ers
DO
C
ontro
l
Savi
ngs
Description Source
City of Conroe
WWTP (TX) 6.4 77%
Add luminescent DO probes and master control panel,
replace (2) 300 hp multi-stage w/ (2) 250 hp single stage
centrifugal dual-point control blowers (efficiency roughly
equal to turbo), replace coarse bubble with fine bubble
diffusers, install modulating butterfly valves at each
aeration basin, maintaining DO at 2 mg/L
Peters et
al., 2008
Green Bay
Metropolitan
Sewer District -
DePere WWTF
(WI)
8 37.5% Replace (5) 450 hp multi-stage centrifugal with (6) 330
hp turbo blowers, add DO probes.
Mont-
enegro
and
Shum-
aker,
2007
Fort Myers
Central
Advanced
WWTP (FL)
11 36.6%
Demonstration project of replacing 250-hp multi-stage
centrifugal with turbo blower in aerobic digester w/
coarse bubble diffuser, average DO of 1 mg/L as opposed
to 1.5 mg/L maintained
Bell et
al., 2010
14
Table 2.1 – General ECM Case Study Survey
Plant
AD
F (M
GD
)
Fine
B
ubbl
e D
iffus
ers
Turb
o B
low
ers
DO
C
ontro
l
Savi
ngs
Description Source
Florence
WWTP
Demonstration
(AL)
9
17%
Add luminescent DO probes and master control panel to
control (3) existing 350 hp multi-stage and (1) 150 hp
multi-stage centrifugal blowers w/ fine bubble diffusers
by throttling intake valve, DO maintained at 2 mg/L DO
Brog-
don et
al., 2008
Unnamed
Poultry
Processing
Facility (MS)
1
22% Add luminescent DO probes and VFD to existing
centrifugal blower w/ fine bubble diffusers
Brog-
don et
al., 2008
Oxnard WWTP
(CA)
22.4
20%
Installed (2) influent TSS meter, updated DO probes to
luminescent probes, implemented model-predictive
control strategy to continuously modify DO setpoint
based on influent TSS and DO with existing single stage
centrifugal dual point control blowers and fine bubble
diffusers
Moise
and
Morris,
2005
15
Table 2.1 – General ECM Case Study Survey
Plant
AD
F (M
GD
)
Fine
B
ubbl
e D
iffus
ers
Turb
o B
low
ers
DO
C
ontro
l
Savi
ngs
Description Source
Phoenix 23rd
Ave WWTP
(AZ)
48 15.3%
Install feed-forward BIOS system (BioChem
Technology, Inc.) with DO, flow, TSS, temperature,
nutrient and flow measurement to control DO setpoints in
different zones, with minimum DO setpoint of 2.0, 1.3,
and 0.7 mg/L in three zones of a modified Ludzack-
Ettinger process, compared to fixed DO setpoints of 2.5,
2.0, and 2.0 mg/L, respectively.
Walz et
al., 2009
Abington
WWTP (PA) 2 5.5%
Install feed-forward/feedback model predictive control
system, with BOD, TSS, nutrient, flow, and DO
measurement in a preanoxic selector/aeration process for
a reduction of DO from 2 mg/L setpoint to average
adjustable setpoint of 1.5 mg/L with minimum and
maximum setpoints of 1.0 and 2.0 mg/L, respectively
Liu et
al., 2005
Enfield WWTP
(CT) 5 13%
Install feed-forward BIOS system (BioChem
Technology, Inc.) with DO, flow, TSS, temperature,
nutrient and flow measurement to control DO setpoints in
different zones of a modified Ludzack-Ettinger process to
unreported values, compared to fixed DO setpoints of
2.75, 2.0, and 0.5 mg/L, respectively.
Liu et
al., 2005
16
17
Local ECM Case Study
Locally, the City of Pembroke Pines WWTP is currently replacing their existing multi-stage
centrifugal blowers with new turbo blowers. Six existing 100 hp and seven existing 200 hp blowers are
being replaced with four 150 HP and four 250 HP blowers provided by Houston Services Industries (HSI).
The blowers currently provide the process air to the 9.5-MGD plant equipped with Sanitaire silver series
fine bubble diffusers, one one-million gallon and one 500,000 gallon surge tanks, and one 70,000 gallon
sludge holding tank. The plant has an average annual daily flowrate (ADF) of 6.75 MGD and an average
annual BOD concentration of 294 mg/L. The system is designed to maintain a minimum DO concentration
of 2.0 mg/L (Pembroke Pines, 2011).
The project is still under construction at the time of publication. However, yearly power savings
estimates range from $27,000 to $73,000 annually, or 5.0% to 15.6% of the existing cost. Capital cost for
the blowers portion of the project is approximately $1,222,000 (Pembroke Pines, 2011). Assuming the
same bond discount rate and inflation assumptions for the life cycle cost analysis discussed later in this
report, a life cycle cost payback of 21 years results assuming $73,000 of annual power savings, to no
payback assuming the $27,000 of annual power savings. However, when considering that the existing
blowers were at the end of their service life and would be required to be replaced, an approximate capital
cost replacement of $900,000 was avoided. This consideration results in a life cycle cost payback of 5
years assuming $73,000 of annual power savings, to a 15 year payback assuming the $27,000 of annual
power savings.
2.2 Fine Bubble Diffusers
The principal types of aeration are diffused aeration, mechanical aeration, and high-purity oxygen
systems. High purity oxygen systems are not within the scope of this study. It has been well established
that diffused air systems, specifically fine bubble diffused air systems are much more efficient at oxygen
transfer than mechanical aeration or coarse bubble diffused air technology (Shammas et al., 2007). The
smaller bubble size produced by fine bubble diffusers has a high surface area to volume ratio, which allows
much higher oxygen transfer with the same volume of air as other technologies. As such, only fine bubble
18
diffused air technologies are considered in this paper. Table 2.2 summarizes fine bubble technologies
possessing the highest standard oxygen transfer efficiencies (SOTEs):
Table 2.2 - Fine Bubble Diffuser Technologies with Highest SOTE’s
Diffuser type and placement
Airflow rate
scfm/diffuser
SOTE at 15-ft
submergence (%)
Ceramic discs 0.4–3.4 25–40
Ceramic domes 0.5–2.5 27–39
Perforated flexible membrane discs 0.5–20.5 16–381
Nonrigid porous plastic tubes 1–7 19–371
1 Wider Range of Transfer Efficiency generally attributed to wider airflow rate range, transfer efficiency generally goes down as airflow rate increases (Shammas et al., 2007)
The perforated flexible membrane diffusers can provide energy savings beyond improved transfer
efficiency. Most membranes are required to be constantly submerged when not in use to prevent diffuser
degradation, including perforated membrane and ceramic diffusers. However, ceramic membranes require
air to be continually fed through the membranes even when the aeration basin is not in use to prevent
permanent fouling of the diffuser pores. Air to perforated flexible membrane diffusers can be completely
turned off, which can result in substantial energy savings (Cantwell et al., 2007). Since the perforated
flexible membrane discs have a high relative SOTE and have operational flexibility to completely turn off
airflow, this technology will be considered as the state of the art for comparison purposes. Membrane
diffusers have a useful life of 5 to 10 years, depending on operating conditions (Schroedel et al., 2010).
2.3 Blower Technology
WWTPs typically use four types of blowers for aeration as listed below:
• Rotary lobe positive displacement blower
• Single-stage dual guide vane blower
• Multi-stage centrifugal blower
• Single-stage turbo blower
19
A brief description of the four technologies are provided below.
Rotary Lobe Positive Displacement Blower
Rotary lobe positive displacement blowers have a wire to air efficiency of 45 to 65 percent, which
is the least efficient of the blower technologies typically implemented in a wastewater aeration process
(Liptak, 2006; O’Connor et al., 2010). Although less efficient (especially at lower speeds), advantages of
the positive displacement blowers are that they have a greater ability to turndown with VFDs compared to
the other blower technologies, can operate at a wide spectrum of pressures, and generally have the lowest
capital cost of the blower alternatives. Another benefit is that the control systems are relatively simple. A
view of a positive displacement blower is provided in Figure 2. 1.
Figure 2.1 – Positive Displacement Blower Cross-Section (Photo by Aerzen USA Corporation)
Single-stage dual guide vane blowers
Dual guide vane control blowers have the ability to turndown speed and flow while maintaining a
relatively constant efficiency compared to multi-stage centrifugal and positive displacement blowers.
Single-stage centrifugal blowers range from 70 percent to 80 percent wire to air efficiency for designs
utilizing advanced impeller and case aerodynamics (Liptak, 2006; O’Connor et al., 2010). Inlet guide
vanes convert pressure drop into rotational energy to increase the efficiency of single stage blowers, and
Inlet Outlet
Rotating Lobes
20
variable diffuser vanes on the blower outlet control the flowrate (Lewis et al., 2004). The vanes continually
adjust their position to optimize efficiency. The dual vane control technology allows for a flow capacity of
approximately 45 to 100 percent with relatively constant high efficiency, and can be operated with a VFD
to achieve additional flexibility. The single-stage dual guide vane blowers tend to have higher maintenance
than other blower alternatives due to more complex mechanics. On plant in South Florida reports annual
maintenance costs of approximately $15,000 per blower, related to accelerated corrosion and locking of
guide vanes due to the humid south Florida climate. A cross section of a dual guide vane control blower is
provided in Figure 2.2.
Figure 2.2 – Dual Guide Vane Control Blower Cross-Section (Graphic by Siemens, Inc.)
Multi-Stage Centrifugal Blowers
Multi-stage centrifugal blowers are the most common type of blower used in the activated sludge
process (Schmidt Jr. et al., 2008), due to relatively high efficiencies compared to positive displacement
blowers and mechanical simplicity compared to single- stage dual guide vane blowers. Multi-stage
centrifugal blowers have a wire to air efficiency between 50 to 70 percent (Liptak, 2006; O’Connor et al.,
2010). Similar to positive displacement blowers, multi-stage centrifugal blowers efficiency decreases with
InletOutlet
Inlet Guide VanesVariable Diffuser Vanes
Impeller
21
speed. Multi-stage centrifugal blowers are also limited in their ability to turndown flow to a minimum of
about 55 percent before the blowers begin malfunctioning, by demonstrating a condition known as surging.
A cross section of a dual guide vane control blower is provided in Figure 2.3.
Figure 2.3 – Multi-Stage Centrifugal Blower Cross-Section (Graphic by Gardner Denver, Inc.)
Single-Stage Turbo Blowers
Turbo blowers are direct-driven by high-speed permanent magnet motors and utilize VFDs to
achieve speed and flow turndown. Turbo blowers have reported wire to air efficiencies of 70 to 80 percent
(Rohrbacher et al., 2010; O’Connor et al., 2010). Rohrbacher et al., 2010, documented three life cycle
analysis case studies where turbo blowers were found to result in 10 to 15 percent present worth cost
savings compared to multi-stage centrifugal blowers. Turbo blowers have 10 to 20 percent greater
efficiency than the most-commonly utilized multistage centrifugal blowers. However, unlike dual vane
single stage blowers, turbo blowers are not capable of maintaining constant efficiencies throughout the flow
Inlet
Outlet
Impeller (one of multiple stages)
22
range, so when turned down the reported high efficiencies of turbo blowers drops off. Turbo blowers use
magnetic or air bearings which reduce maintenance compared to other blowers.
Besides having a high efficiency, advantages of turbo blowers are smaller footprint and ease of
installation compared to other blower options. Disadvantages of turbo blowers are that they typically have
a higher capital cost than multi-stage centrifugal or positive displacement blowers, and the airflow
capacities are currently limited to approximately 7,000 standard cubic feet per minute (scfm) meaning
multiple units must be installed in larger systems, or dual units that consist of two blowers operated by a
common rotor and stator. Turbo blowers were recently introduced to the municipal market in 2007,
therefore the general long-term performance is unknown (O’Connor et al., 2010). A cross section of a dual
turbo blower is provided in Figure 2.4.
Figure 2.4 – Turbo Blower (Dual) Cross-Section (Graphic by APG Neuros)
Selection of Blower Technology
Turbo blower and single-stage dual guide vane blowers have similar efficiencies. However, dual
guide vane blowers typically require more maintenance due to more mechanical complexity, which can be
exacerbated by the humid south Florida climate. For the purpose of predicting capital and O&M costs,
turbo blowers are considered to be the state of the art. Based on efficiency and capital cost, it will be
demonstrated that turbo blowers have equivalent or less present value cost compared to the conventional
Outlet
Inlet
Impeller
StatorRotor
Air foil bearings
23
blower alternative of multi-stage centrifugal blowers, while utilizing less energy (O’Connor et al., 2010).
Table 2.3 summarizes the comparison of key blower technology parameters.
Table 2.3 – Blower Technology Comparison
Parameter Positive
Displacement1 Multi-Stage Centrifugal1
Single-Stage Dual Guide Vane1 Turbo2
Wire to Air Efficiency 45 - 65 50 - 70 70 - 80 70 - 80
Capital Cost Factor3 1 1.5 2.5 2.4
VFD Capability Yes Limited
Yes but not necessary to achieve high efficiencies
Required
1. (Liptak, Keskar, 2006), (O’Connor, 2010) 2. (Rohrbacher, 2010), (O’Connor, 2010), (Hazen and Sawyer, 2011), (Atlas Copco, 2008) 3. Capital cost factor indicates ratio of capital cost from 1 technology to the other. For example, multistage centrifucgla blowers are approximately 1.5 times more expensive than positive displacement blowers
2.4 DO Control Strategy
The ratio of minimum to maximum oxygen demand within a typical activated sludge process
varies from approximately 3:1 to 5:1 between the peak and off-peak hours. For smaller plants the ratio can
be as much as 16:1 (Tchobanoglous et al., 2003). As wastewater flow and strength fluctuate, there is a
corresponding fluctuation in the amount of oxygen required to provide treatment. It is common to maintain
a DO level of 1 to 3 mg/L in aeration basins to ensure adequate oxygen is supplied to sustain the
microorganisms in the wastewater. There are two main alternatives for controlling the DO level in aeration
basins; manual DO control, or automatic DO control.
2.4.1 Manual Control
The most simple DO control strategy is manual control, where operators take periodic manual
readings of DO, or less commonly parameters related to DO such as nitrate concentration, ammonia
concentration, or average influent flow and mixed liquor suspended solids (MLSS) concentration. The
operator then manually sets a corresponding airflow rate to meet the required DO by adjusting valves or
blowers settings. However, because operators must conservatively set the airflow to the maximum worst-
case airflow demand incurred during peak flow and wastewater strength, the result is that during many
24
times of the day DO levels higher than 1 to 3 mg/L are supplied, resulting in wasted energy. If additional
readings are taken throughout the day to more closely match air supplied to DO required, then labor costs
are increased.
Supplying excessive DO beyond that required by the activated sludge process can inhibit nutrient
removal of phosphorous. Conversely, supplying too little DO can also cause problems with effluent quality
like TSS, BOD, and ammonia. Reduced settleability and breakthrough of nitrite into the effluent causing
disinfection problems are also a concern related to low DO (Ekster et al., 2007).
2.4.2 Automatic DO Control
The main alternative to manual DO control is the automatic DO control strategy, which utilizes
DO sensors to continuously take DO readings and “feedback” signals to a controller that automatically
adjusts airflow to maintain a predetermined DO setpoint, (typically 1 to 3 mg/L), by continuously adjusting
the blowers and/or air distribution control valves to each basin. As such, implementing automated DO
control can greatly reduce electricity costs, operator workload, and help to maintain consistent effluent
quality.
By consistently matching the amount of air supplied to the amount of oxygen required to maintain
a DO setpoint, automatic DO control can prevent overaeration and resulting wasted electricity when
compared to manual DO control. However, the method of feedback control has some inherent problems in
that it is constantly controlling airflow to affect a change in DO after the high or low DO condition has
already occurred (and energy wasted). The automatic DO control strategy can also be problematic due to
the delayed response in DO following change in airflow. Additionally, problems with the control logic can
cause wide valve oscillations and blower output oscillations. In the past, unreliable control loop elements
that were hard to control and prone to fail such as DO meters have been problematic when utilizing the DO
control strategy (Ekster et al., 2005). However, recent advances in DO probe technology have increased
the reliability of using automatic DO control.
A variety of components in an aeration system can be controlled with the automatic DO control
strategy to optimize and control air flowrate. Depending on the type of blower technology, these options
include changing the total system airflow by continuously throttling the blower intake valve, changing the
25
speed of the blower motor with a VFD, repositioning the inlet guide vanes and discharge control vanes, or
other methods. The airflow to individual aeration zones can be controlled by adjusting air distribution
control valves. There are various DO control strategies available which are discussed in the following
sections. Figures 1.7 though 1.10 in the introduction illustrate the automatic DO control concept and
associated equipment.
2.4.3 DO Probes
One limiting factor in implementing well functioning DO control systems in the past has been the
unreliability of DO probes. Older galvanic and polarographic membrane-type DO probe technology using
anodes, cathodes, membranes, membrane-cleaning devices, and electrolyte solutions are relatively
unreliable (Liptak, 2006). Membrane DO probes are fragile and utilize an electrochemical process which
fouls the sensor, requiring frequent cleaning, maintenance, and recalibration (Hope, 2005).
Optical DO sensors use a light quenching process, as opposed to membrane-type probes that
utilize an electrochemical process which consumes oxygen. Optical DO sensors do not require flow across
the probes and do not intrinsically foul with byproducts from the oxygen-consuming electrochemical
measurement process. The optical DO probes are more accurate than membrane-type probes in measuring
low DO concentrations typical in activated sludge processes. Optical sensor probes have been installed in
activated sludge processes throughout the United States between 2000 and 2010 and have a record of
successful operation proving their reliability (Brogdon et al., 2008). Limited monthly and annual
maintenance and calibration of the optical probes are suggested by the manufacturers. The maintenance is
relatively unintensive compared to membrane probes which require time-consuming weekly calibration and
bimonthly membrane replacement of membranes (Brogdon et al., 2008).
2.4.4 Modulating Valves
To control DO level in different parts of the aeration basins, an automatic DO control system will
send a signal to one or more motor-operated modulating valves to open or close to sustain DO level within
a desired range. Automatically actuated equal percentage butterfly valves are commonly used in aeration
systems. Facilities with valve actuators that are linear, equal percentage, and quick opening have had
success in controlling airflows (Liptak, 2006). The linear, equal percentage operators increase valve flow
26
capacity by the same percentage for each equal increment of travel, which simplifies control of the valves
and reduces tuning and calibration by instrumentation engineers. Therefore, automatically actuated equal
percentage butterfly valves are considered as state of the art.
2.4.5 Flow Meters
Automatic DO control systems typically have flow meters associated with each major control
valve so that operators can ensure flowrates are being maintained within a desired range in each aeration
basin section. Pitot tube, venturi tube, or thermal dispersion meters are typically used for measuring air
flow in aeration. The pitot tube is less accurate than the venturi or thermal dispersion. The venturi is
accurate but requires long runs of straight pipe upstream and downstream of the meter. Thermal dispersion
meters also require some distance of straight pipe upstream and downstream of the meter (Liptak, 2006).
Thermal dispersion devices in air service require cleaning once every six months (Hill et al., 2007),
whereas venturi flow tubes are not required to be removed and maintained. For this reason, venturi flow
tubes are considered the state of the art for this analysis. Figure 2.4.5.1 demonstrates the three main types
of flow meters.
Pitot Tube Venturi Flow Tube Insert Thermal Dispersion (photo by ABB group) (photo by BIF Flow Measurement) (photo byABB group)
Figure 2.5 – Typical Flow Meters for Measuring Air Flowrates
Pitot tube
Transmitter
Differential pressure connections, transmitter not shown
One heated and one unheated temperature sensor
Transmitter
27
2.5 Piping
Pipe materials for aeration process piping are often stainless steel, fiberglass, or plastics suitable
for high temperatures. Mild steel or cast iron with external and interior coatings can also be used
(Tchobanoglous, 2003). Type 304 and 316 stainless steel are most commonly used in WWTPs. Type 304L
or Type 316L should be used when field welding is required due to the low carbon content. Type 316
stainless steel is approximately 40 percent more expensive than 304 stainless steel (MEPS International
LTD, 2012). Schedule 10S is a common thickness of stainless steel piping in aeration applications. Type
304L stainless steel piping provides the anti-corrosion benefits and durability of stainless steel with field-
weldability. For this reason, Schedule 10S 304L stainless steel is assumed for this analysis.
2.6 Summary of Technologies
The objective of this thesis is to identify the state of the art technology for ECMs in the activated
sludge process and determine the feasibility of their implementation on a cost-benefit basis at WWTPs in
South Florida. The preceding section has discussed the various alternatives for ECMs in the activated
sludge process. It is emphasized that the technologies identified here are for the purposes of providing a
general framework to estimate the costs and benefits of implementing ECM’s at WWTPs on a regional
basis. Every WWTP is unique in what technologies are most appropriate and could vary significantly from
those identified here on an individual basis. The findings of the preceding sections are summarized in
Table 2.4:
28
Table 2.4 – Summary of Technologies
System Component State of the Art ECM No.
Fine Bubble Diffusers Perforated flexible membrane disk in grid pattern 1
Piping 304 L Sch 10S stainless steel 2
Blowers Single stage centrifugal turbo 2
DO control Automatic DO Control 3
DO probes Optical DO probes 3
Modulating valves Modulating equal-percentage butterfly 3
Flow meters Thermal dispersion or venturi 3
2.7 Key Assumptions For Aeration Model
2.7.1 DO Levels
To model the energy consumption of implementing the various DO control strategies identified in
Section 2.4, case studies and authoritative texts were researched to determine the appropriate values to be
used. WEF MOP 8 recommends a design value of 1 to 2 mg/L DO for aerobic selectors (Krause et al.,
2010). (Mueller et al., 2002 indicates that a design value of 2 mg/L is typical for designing activated sludge
processes at average loading. Stenstrom et al., 1991indicated that values to achieve adequate nitrification
range from 0.5 to 2.5 mg/L DO.
Manual DO Control – DO Level Assumptions
To ensure that the required DO concentration is maintained at all times during the day, operators
using a manual DO control strategy will typically set the airflow to a high setting that will meet the
maximum worst-case airflow demand during peak flow and loading. In turn, this strategy often results in
over aeration except when the air demand matches the worst-case flow and loading. Available case studies
using manual control were researched to determine an average design value to assume for modeling
aeration system energy consumption and detailed in Table 2.5. Table 2.5 demonstrates that manually
controlled DO levels throughout the day vary widely due to variable oxygen demand and constant air
supply. The mean value of available case studies indicates an average DO level of 3.2 mg/L is common for
29
manually controlled systems. Rounding to the nearest whole number, a conservative design value of 3.0
mg/L is assumed which may slightly understate the amount of energy typically consumed with manual DO
control based on the case studies reviewed. It will be shown this assumption should not greatly affect the
calculated payback.
Table 2.5 – Manual DO Control - Case Study DO Levels
Min
(mg/L)
Max
(mg/L)
Avg
(mg/L) Source
1 6 2.3 ( Malcolm Pirnie, 2005)
1.5 6 3.1 (Brischke et al., 2005)
2 7 3.7 (Dimassimo, 2000)
2 7 3.6 (Schroedel et al., 2009)
Total Average 3.2
Model Value 3.0
Automatic DO Control – DO Level Assumptions
Automatic DO control strategy relies on finding a suitable setpoint which will maintain adequate
DO levels at all design loadings. Some case studies using automatic DO control were researched to support
an average design value to assume for modeling aeration system energy consumption and detailed in Table
2.6. Table 2.6 demonstrates that automatically controlled DO level setpoints average approximately 1.4
mg/L for the case studies reviewed. Actual DO setpoint requirements will vary for specific WWTPs on a
case by case basis, depending on the wastewater constituents and strength, process design, effluent limits,
and other factors. Based on these results, a conservative design value of 1.5 mg/L is assumed.
30
Table 2.6 – Automatic DO Control – Case Study DO Levels Min
(mg/L)
Max
(mg/L)
Avg
(mg/L) Source
0.5 2.1 1.5 (Sunner, 2009)
0.5 2.75 1.75 (Liu, 2005)
0.75 3 1.4 (Brischke, 2005)
0.8 1.2 1 (Moise and Norris, 2005)
1.4 1.6 1.5 (Leber, 2009)
Total Average 1.4
Model Value 1.5
2.7.2 Blower Efficiency Assumptions
Rohrbacher et al., 2010, completed multiple life-cycle cost analyses comparing multi-stage
centrifugal blower to single-stage turbo blowers from 150 horsepower to 500 horsepower based on blower
curves provided by manufacturers. The study included over 17 single-stage turbo blowers and 5 multi-
stage centrifugal blowers. The study indicated that the average wire-to-air efficiency of single-stage turbo
blowers over their operating curve was approximately 72 percent, whereas the average efficiency of multi-
stage centrifugal blowers was 62 percent. O’Connor et al., 2010, indicates the typical range the
efficiencies of single-stage turbo blowers to be 10% higher than multi-stage centrifugal blowers. The
values used in the Rohrabacher et al., 2010, case studies are at the lower end of this range and are used as
conservative assumptions.
2.7.3 Flowrate Assumptions
The typical planning period used for calculating life cycle cost analyses and also used in this study
is 20 years. Accordingly, the flowrate and loading used as the basis of comparison for each ECM and
scenario is the average flow over the 20 year planning period. Assuming a linear growth in loading and
flowrate over the 20 year design period, the average flowrate and loading is equal to the year 2021 average
daily flow and loading. The average flows over the 20 year planning periods are determined using various
methods depending on the data available for each plant and are discussed in Section 5.
31
2.7.4 Aeration Modeling Global Assumptions
The following assumptions are made for modeling the performance of the proposed aeration
systems.
Minimum Mixing Requirements
It is required to maintain a minimum level of aeration at all times to maintain minimum mixing
requirements. According to (Mueller et al., 2002) and (Krause et al., 2010), for a full-floor grid, 0.12
cfm/sf is a typical value for providing adequate mixing.
Minimum and Maximum Flow Per Diffuser
According to Sanitaire literature (Sanitaire, 2010), the Silver Series II diffuser has a range of 0.5 to
4.5 cfm per diffuser. Since the SOTE of the diffusers drops off at higher ranges, and to guard against
overshooting the diffuser range causing coarse bubble production, a conservative limit of 3.0 cfm per
diffuser is assumed at maximum day average flow and loading.
Beta
Beta is a factor which reduces the predicted oxygen transfer efficiency of the system based on total
dissolved solids concentration effects. A lower beta value results in reduced oxygen transfer per unit
volume of air supplied and higher energy consumption. According to (Mueller et al., 2002), for municipal
wastewater where TDS < 1,500 mg/L, an appropriate Beta value is 0.99. However, (Tchobanoglous et al.,
2003) report that values of 0.95 – 0.98 are typical. TDS concentrations greater than 1,500 mg/L is not
common in domestic wastewater, even at facilities blending nanofiltration or reverse osmosis concentrate
with effluent (Stanley et al., 2009). The high value of the (Tchobanoglous et al., 2003) recommended
range of 0.98 is assumed for the model.
Alpha
The alpha factor is the ratio of oxygen mass transfer coefficients in dirty water versus clean water.
It is generally accepted that alpha factors vary as a function of SRT in conventional activated sludge
treatment processes. A lower alpha value results in reduced oxygen transfer per unit volume of air supplied
and higher energy consumption. Alpha factors for fine bubble diffused aeration fall within 0.1 to 0.7, with
the average observed value of 0.4 (Krause et al., 2010). The alpha factors used in the models were
32
determined based on published SRT versus alpha data (Rosso et al., 2005). A conservative alpha value of
0.43 was assumed based on published SRT versus alpha data except in scenarios where full nitrification is
achieved, in which case an alpha value of 0.5 is assumed as would be expected with a higher SRT
associated with nitrification (Krause et al., 2010).
Temperature
A range of 23 to 27 degrees Celsius are typically recorded for wastewater temperatures during
sampling of WWTPs in South Florida. An average of 25 degrees is assumed for the model.
Standard Oxygen Transfer Efficiency
Tables that relate SOTE to flow per diffuser are provided by the diffuser manufacturer. Silver
Series II diffuser is assumed. A best fit fourth order curve is fit to the SOTE data available from Sanitaire
and is provided in Section 4.2.3 (Sanitaire, 2010).
Tau
The tau value (τ) is a termperature correction factor for the oxygen saturation value. Since
Henry’s law constant increases with increasing temperature, a termperature correction for the oxygen
saturation value must be applied. τ is interpolated using empirical oxygen saturation values from the
following Figure 2.6 (Mueller et al., 2002). A best fit exponential curve is fit to the data to obtain the
equation used in the model to estimate τ.
y = 1.5394e-0.02x
R² = 0.9925
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30 35 40
Tau (
dim
ensio
nles
s)
Temperature (°C)
Figure 2.6 – Temperature vs. Tau
33
III. LITERATURE REVIEW – COST ESTIMATING METHODS AND ASSUMPTIONS
3.1 Cost Estimate Level of Accuracy
The capital cost of construction for implementing the proposed ECM’s are estimated to compare
to the life-cycle cost evaluation of operating and maintaining the ECM’s. Cost estimates are by definition
not completely accurate, they are an estimate. A range of unknown and constantly changing conditions
affect the accuracy of an estimate, such as the economy, market conditions, and competiveness of bidding a
specific job, which in turn affect material, equipment, and labor rates (ASPE, 2008). The preliminary-
design level of project definition for ECM implementation at each wastewater treatment facility does not
imply a high level of accuracy. Rather, the goal of this analysis is to provide a reasonable level of
accuracy.
Multiple agencies, such as the Association for the Advancement of Cost Engineering (AACE),
American National Standards Institute (ANSI), and the American Society of Professional Estimators
(ASPE) recommend classifying cost estimates based on degree of project definition, end usage of the
estimate, estimating methodology, expected accuracy range, and the effort and time needed to prepare the
estimate. The Water Environment Federation – Manual of Practice 8 recommends using the AACE system
(Krause et al., 2010). ANSI recommends a three-tiered system of estimate classification. Both AACE and
ASPE define a five-tiered range of estimate classes, with AACE Class 1 being the highest level or project
definition and AACE Class 5 being the lowest level of project definition.
The AACE classes of estimate levels are reproduced in Table 3.1 below for reference and to help
demonstrate how the level of estimate used in this paper was determined by AACE International
Recommended Practice No. 18R-97 (Christensen et al., 2005).
34
Table 3.1 - AACE Estimate Class Level Characteristics (Christensen, 2005)
ESTIMATE
CLASS
LEVEL OF
DEFINITION
PURPOSE METHODOLOGY
ACCURACY
RANGE
(Expected)
EFFORT
(As %
Of total cost)
Class 5
0% to 2% Concept
Screening
Capacity Factored,
Parametric Models,
Judgment, or
Analogy
Low: -20% to -50%
High: +30% to +100%
0.005%
Class 4 1% to 15% Study or
Feasibility
Equipment
Factored or
Parametric Models
Low: -15% to -30%
High: +20% to +50%
0.01% to 0.02%
Class 3
10% to 40%
Budget,
Authorizati
on, or
Control
Semi-Detailed Unit
Costs with
Assembly Level
Line Items
Low: -10% to -20%
High: +10% to +30%
0.015% to
0.05%
Class 2
30% to 70% Control or
Bid/
Tender
Detailed Unit Cost
with Forced
Detailed Take-Off
Low: -5% to -15%
High: +5% to +20%
0.02% to 0.1%
Class 1
50% to 100% Check
Estimate or
Bid/Tender
Detailed Unit Cost
with Detailed
Take-
Off
Low: -3% to -10%
High: +3% to +15%
0.025% to 0.5%
Study
Facilities
20% to 30% Study or
Feasibility
Semi-Detailed Unit
Costs with
Assembly Level
Line Items
Low: -20%
High: +30%
0.1% to 0.3%
Table 3.1 and the Estimate Input Checklist and Maturity Matrix available in the AACE
International Recommended Practice No. 18R-97 were referenced to ascertain the recommended class of
estimate and associated accuracy range of the capital cost estimates. The level of project definition for the
case studies detailed in this paper demonstrate characteristics of both a Class 4 and Class 3 cost estimate.
The estimated level of project definition is 20 to 30 percent and the cost estimates do comprise semi-
35
detailed unit costs with assembly line items, consistent with Class 3 estimate characteristics. Additionally,
preliminary mechanical, electrical, instrumentation, and structural site drawings are completed, which are
characteristic of a Class 3 cost estimate and not a Class 4. However, when referencing the Estimate Input
Checklist and Maturity Matrix, many required deliverables are not developed to a preliminary or complete
level characteristic of a Class 3 estimate. As a conservative assumption, the cost estimates completed for
this project are considered to be AACE Level 4. Since the estimate does exhibit many characteristics of a
Class 3 level, the most conservative recommended Class 3 accuracy range (-20 to +30 percent) is assumed,
which falls within the confines of the Class 4 estimate accuracy (Low -15 to -30 percent, High +20 to 50
percent).
3.2 Life Cycle Cost Analysis Method And Assumptions
The electricity and maintenance costs will be incurred over the life of the operation of the plant.
Electricity costs are subject to a different rate of escalation than general inflation. For this reason, the
appropriate equations to use for calculating net present value considering the contrasting escalation rate of
energy costs over general inflation are the Present Worth of a Geometric Gradient Series equations.
(1)
Where P = present value
A = annuity value
n = number of periods
i = average annual bond rate (%)
g = average annual inflation rate (%)
The appropriate equation to use for calculating net present value of annual costs that rise with
inflation such as operation and maintenance costs over general inflation are the Present Worth of a Periodic
Series equation.
( ) ( )
giifi
nAP
giifgi
igAPnn
=⎥⎦⎤
⎢⎣⎡+
=
≠⎥⎦
⎤⎢⎣
⎡
−++−
=−
1
111
1
1
36
(2)
Where P = present value
A = annuity value
n = number of periods
i = average annual bond rate (%)
Payback
This paper compares the energy savings of implementing ECMs to the sum of capital costs, and
present value of change in operation and maintenance costs and foregone capital costs. The payback is
defined as the point in time at which the accruing energy savings realized by implementing the ECMs is
equal to the capital cost and change in O&M cost, and foregone capital cost. This can be expressed as
follows:
Penergy saving,n = Capital Cost + Pforegone caital + P∆O&M,n (3)
Where Penergy savings = present value of energy savings at time = n
Capital Cost = capital cost for implementing ECMs
Pforegone capital = capital improvements avoided by implementing ECMs
P∆O&M,n = present value of change in O&M costs due to implementing ECMs
Payback = n = number of periods per equation (1) and (2) (years), solved for iteratively in
equation (3)
Inflation rate
The Consumer Price Index (CPI), reported by the U.S. Bureau of Labor Statistics, is the most
common indicator for price and wage inflation. It is the most common indicator used by businesses and
labor unions in making economic decisions and adjusting income payments. Over 80 million Americans
collecting Social Security, Federal Civil service pensions, and Federal food stamp recipients are affected by
the CPI (US BLS, 2010).
The Producer Price Index is another common indicator for inflation. The PPI measures the average
change in selling prices received by domestic producers of goods and services over time from the
37
perspective of the seller. The PPI contrasts with the CPI, which measures price change from the
perspective of the purchaser. Sellers' and purchasers' prices differ because of distribution costs, sales and
excise taxes, and government subsidies (US BLS, 2010).
Since the planning period for the life-cycle cost analysis is over 20 years, the annual average CPI
is assumed. The US BLS has been reporting CPI statistics since 1919. The US BLS 1919 to 2010 annual
average CPI inflation rate is 3.0 percent. For comparison, the more recent US BLS 1991 to 2010 20-year
annual average CPI inflation rate is similar at 2.5 percent, whereas the 20-year PPI average is 2.3 percent
(US BLS, 2010). For the purposes of this analysis, the more conservative 2.5 percent inflation rate is
assumed, which will effect wages and electricity rate. The small difference between CPI and PPI will not
have a substantial effect on a lifecycle cost analysis.
Electricity costs and electricity escalation rate
Electricity rates used in the life cycle cost analysis are subject to escalation over the course of the
planning period and are taken into account. The Annual Energy Outlook (AEO) reports released by the
United States Energy Information Administration (US EIA) are used to predict trends in the national price
of electricity. According to the 2011 AEO, long term electricity trends will be relatively steady. Figure 3.1
demonstrates that the 2011 real average electricity price of 9.0 cents per kilowatt-hour (kWh) is predicted
to increase to 9.2 cents per kWh in 2035 (in 2011 dollars) for a predicted 0.09 percent annual rise in real
electricity rate over the rate of inflation (US EIA, 2011).
38
8.8
8.8
8.9
8.9
9.0
9.0
9.1
9.1
9.2
9.2
9.3
2010 2015 2020 2025 2030 2035
Cent
s / k
Wh
Year
Figure 3.1 –2011 - 2035 AEO Report Predicted US Electricity Real Rates
Variations in key assumptions in the AEO reports can result in different outlooks for electricity
prices, especially in the long term. Figure 3.2 below demonstrates the variation in predicted electricity
inflation rates from the AEO 2006 report to the current AEO 2011 report. The 2009 AEO Report predicted
a rise in energy inflation due to the 2008 spike in global oil prices. More recently, predicted energy
inflation has dropped and actually turned negative due to the 2010-2011 global recession. The AEO
predicts electricity prices for “side cases”, based on the sensitive variables of US annual gross domestic
product (GDP) and global oil prices, and the effects of the variations in those variables are also
demonstrated in Figure 3.2 and Table 3.2. The assumptions for the AEO 2011 Report side case
assumptions are included in Table 3.3.
39
‐0.6%
‐0.4%
‐0.2%
0.0%
0.2%
0.4%
0.6%
0.8%
1.0%
2005 2006 2007 2008 2009 2010 2011 2012
AEO Re
port Ann
ual Inflatio
n Pred
iction
Year
Base Case
High Economic Growth
Low Economic Growth
High Oil Price
Low Oil Price
Figure 3.2 – 2006 – 2011 AEO Report Predicted US Electricity Annual Real Inflation Rates
Table 3.2 – 2006 – 2011 AEO Report Average Predicted US Electricity Annual Real Inflation Rates
AEO Report Year Base Case
High Economic Growth
Low Economic Growth
High Oil Price
Low Oil Price
2006 – 2011 Average 0.08% 0.25% -0.13% 0.20% 0.08%
Table 3.3 – 2011 AEO Report Base and Side Case Assumptions
Low GDP
Base GDP
High GDP
2.1% 2.7% 3.2%
Low Oil Price
Base Oil Price
High Oil Price
$50 $78 $200
Due to the variability in AEO electricity inflation predictions, the average of the base case from
the 2006 through 2011 reports of 0.08 percent is assumed. While this rate will have a minimal effect on the
outcome of the model, adding the capability into the model for consideration of energy inflation provides
40
the capability of modeling the effects of unpredicted future fluctuations in energy price or theoretical
scenarios.
The electricity costs for the facilities in this report were obtained through the average cost per
kWh. According to interviews with plant staff and review of electric bills, the three facilities in this study
are currently paying an average price of $0.07 per kWh (FPL, 2011). As recently as the end of 2009,
electricity costs for WWTPs in south Florida were averaging $0.09 per kWh. A recent precipitous drop in
southeast Florida plant’s electrical bills from 2009 to 2010 of approximately 20 percent occurred, due to a
reduction in “pass through fuel charge” from FPL. If fuel charges increase again on a similar scale, life
cycle cost analysis results could be greatly affected.
Discount (Bond) Rate
The discount rate is the return on capital that could be earned had the capital been invested or used
to pay down debt, as opposed to utilized for the capital project. The interest that could have been earned or
saved is “discounted” from the life-cycle cost analysis as a deduction to the net present value of a project.
The regulations that govern the State Revolving Fund (SRF) Program (40 CFR 35.2130[b][3], U.S. EPA
[1978]) mandate that facilities using the program use the discount rate established by the United States
Environmental Protection Agency (US EPA) for the year that facilities planning commences (Krause et al.,
2010). The Florida Department of Environmental Protection (FDEP) calculates the SRF funding rate based
on the bond market rate for interest established using the “Bond Buyer” 20-Bond GO Index published by
the Thomson Publishing Corporation. For the April to June 2011 3-month period, the bond market rate is
4.70 percent. It should be noted that projects that qualify for funding through the SRF program typically
receive funding at 60 percent to 80 percent of the market rate, which would improve the results of the life-
cycle analysis. As a conservative assumption, no SRF funding revenue is assumed for the ECM analyses.
The United States Department of Energy (US DOE) annually publishes required discount rates to
use for projects funded under the Federal Energy Management Program (FEMP) in the Energy Price and
Discount Factors for Life-Cycle Cost Analysis Supplement (OMB, 2010). The discount factors reported
are used with the FEMP procedures for life-cycle cost analysis established by the US DOE in Subpart A of
Part 436 of Title 10 of the Code of Federal Regulations (10 CFR 436A) and summarized in the National
41
Institute of Standards and Technology (NIST) Handbook 135 (Fuller et al., 1995). The discount factors
are specifically for use with federal projects related to energy and water conservation investments. While
the study facilities are not federal facilities, the aforementioned documents provide standardized guidelines
to follow when conducting life cycle cost analyses at publicly owned facilities. The US DOE Supplement
requires that applicable facilities use a nominal discount rate based on long-term Treasury bond rates
averaged over the 12 months prior to the preparation of this report. The US Treasury Bond rate
approximates the interest rate a municipality would have to pay for a municipal bond issue. The US DOE
Supplement indicates that a nominal discount rate of 3.9 percent, which includes inflation, be used as the
discount rate for life-cycle cost analyses completed in 2011 (OMB, 2010).
Based on the FDEP, SRF, and US DOE recommended discount rates for public project life-cycle
cost analyses and the prevailing market interest rate for municipal bonds, a conservative nominal discount
rate of 4.7 percent which includes inflation is assumed for this analysis. It should be noted that factors such
as funding aid through programs such as the SRF program could greatly increase the cost-benefit ratio of
the analysis.
Planning Period and Life Expectancies
The planning period used for calculating life cycle cost analyses is typically 20 years. Equipment
is typically expected to have a design life expectancy of 15 to 20 years (Krause et al., 2010). Equipment
that is expected to last longer than the planning period can be recognized by realizing a salvage value at the
final year. Equipment that lasts less than 20 years will have replacement or overhaul costs for the
corresponding year. Buildings, structures, and pipelines generally have a life expectancy of 50 years, with
metal structures having a lower life expectancy (Krause et al., 2010).
3.3 Capital Cost
Following design of the proposed ECMs, a capital cost estimate of construction is completed. A
majority of the direct capital costs of construction are estimated using 2011 - RS Means Construction Cost
Data literature (Waier et al., 2011). RS Means Construction Cost Data is an industry standard for cost
estimating data. Major direct capital costs for proprietary and niche industry equipment, such as fine bubble
diffusers, blowers, and instrumentation are not available in RS Means and are estimated based on budgetary
42
quotes from specialty contractors or manufacturers. Markup and contingency percentages for overhead,
profit, mobilization, bond and insurance, and contingency are interpreted based on prevailing local rates
and information from Water Environment Federation – Manual of Practice No. 8, which is a resource that
is specific to the utility industry (Krause et al., 2010).
3.3.1 Cost of Blower Technology
The cost of turbo blowers varies between manufacturers. The cost of blowers were collected from
two data sources for various manufacturers and models. The capital cost assumed for the cost analysis is
the average of the costs for each data source. Cost data for turbo blowers was obtained from the USEPA
2010 study (O’Connor et al., 2010) and from (Rohrbacher et al., 2010), and are presented in Table 3.4
below:
Table 3.4 – Cost of Blower Technologies
hp Budget $ Average hp Budget $ Average
50 $56,0001 $79,000
250 $180,0001
$170,000 50 $102,0001 250 $151,0002
75 $75,0001 $75,000 250 $165,0002
100 $115,0001 $104,000
250 $168,0002
100 $93,0002 250 $188,0002
150 $120,0001 $127,000
300 $175,0001
$159,000
150 $134,0002 300 $142,0001
200 $120,0001
$122,000
300 $119,0002
200 $160,0001 300 $119,0002
200 $86,0002 300 $143,0002
200 $90,0002 300 $156,0002
200 $93,0002 300 $208,0002
200 $124,0002 300 $209,0002
200 $128,0002 400 $275,0001
$202,000 200 $176,0002 400 $132,0002
400 $198,0002
500 $325,0001 $325,000 (1) (O’Connor et al., 2010) (2) (Rohrbacher et al., 2010)
43
3.3.2 Cost of Fine Bubble Diffused Aeration Technology
The costs for fine bubble diffused aeration headers and membranes depend on a variety of factors,
such as material, amount of diffusers, and amount of grids. As such they must be assessed on a case by
case basis. Quotes from two manufacturers that provide flexible porous membrane fine bubble diffusers
were obtained for each plant studied. Prices are based upon market pricing of these systems based on
typical materials of construction, factory testing, warranty and field services. As a competitive bidding
scenario amongst the two manufacturers would be likely, the low cost estimate is assumed. Details on the
cost of aeration grids for each technology are provided in Table 3.5.
Table 3.5 – Cost of Fine Bubble Diffusers
Plant Description Manufacturer Estimate
Boca Raton WWTP
10,700 diffusers, 18 grids ITT Water and Wastewater - Sanitaire $430,000
Aquarius Technologies $320,000
Broward County North Regional WWTP
20,160 diffusers, 48 grids ITT Water and Wastewater - Sanitaire $845,000
Aquarius Technologies $600,000
Plantation WWTP 11,020 diffusers, 18 grids ITT Water and Wastewater - Sanitaire $450,000
Aquarius Technologies $330,000
3.3.3 Foregone Capital Replacement Costs and Salvage Value
Foregone capital replacement costs are an important component of lifecycle cost analyses. If new
aeration equipment was not installed at the study facilities, eventual significant capital investments would
be required for replacement of existing mechanical aeration equipment. The existing mechanical aerators
at the plants in this study have surpassed their typical 20 year lifespan. Typically equipment beyond a 20
year lifespan would be considered deferred maintenance and have no present value worth. However, for
this analysis it is recognized that most facilities keep this equipment in operation for more than the 20 year
design life. For this reason a conservative assumption of 5 years of remaining life is assumed for existing
mechanical aeration equipment for the life cycle analysis. Table 3.6 below summarizes major equipment at
each plant that would require eventual replacement and their characteristics.
44
Table 3.6 – Major Equipment Requiring Eventual Replacement
Aerators Blowers App.
Date of Install
Typical Useful
Life Current Life
Plant Amt Capacity
(hp) Amt Capacity
(hp)
Assumed RemainingLife
Boca Raton 9 100 3 200 1986 1 20 25 5
N Broward 24 100 0 1982 2 20 29 5
Plantation 9 100, 125 0 1989 3 20 22 5
1. (Hazen and Sawyer (2), 2007) 2. (Hazen and Sawyer (1), 2007) 3. (Hazen and Sawyer, 2004)
Salvage value of equipment is not considered in this analysis at 20 years. Mechanical aerators
replaced at 5 years would have a salvage value at the end of the 20 year time period under the baseline
case. However, under the ECM No. 1, No. 2, and No. 3 case, significant salvage value would also remain
at the 20 year time period for the blower building and piping network although the blowers, diffusers, and
instrumentation would theoretically be at the end of their useful life with no salvage value. Due to the
multiple competing salvage values of assets under the baseline versus ECM No. 1 through 3 cases, salvage
value is not considered in this analysis.
3.4 Operation and Maintenance Costs
Maintenance costs are typically accounted for assuming 1 percent of equipment capital costs
annually (Krause et al., 2010). This does not include periodic overhauls or major parts replacements.
Maintenance costs are assumed to escalate at the same rate as general inflation. O&M costs for
components of this study were obtained from various sources and are provided as Table 3.7 below:
45
Table 3.7 – Major Equipment Requiring Eventual Replacement
System Component Description O&M Costs Source
Base Case -
Mechanical Aerators
Annual general
maintenance
$1,000 1% rule of thumb and
$100K manufacturer’s
quote for replacement
Base Case - Manual
DO Measurement
Collect DO manually
one or more times per
day
30 minutes per shift Boca Raton WWTP staff
interview
ECM No. 1 - Fine
Bubble Diffusers
Replace Membranes in
every 7 to 10 years
Approximately $6 per
membrane, 5 minutes
per membrane
(Sanitaire, 2010); (Rosso
and Stenstrom, 2006)
ECM No. 1 - Fine
Bubble Diffusers
Clean membranes, hose
from top of tank
8 manhours per tank
based on 8,500 sf tank
with 2,400 diffusers
(Rosso and Stenstrom,
2006)
ECM No. 1 - Multi-
Stage Centrifugal
Annual general
maintenance
1.5% of Equipment
Capital Cost
(Rohrbacher, 2010)
ECM No. 2 – Turbo
Blowers
Annual filter
replacement, inspection,
adjustment, parts
replacement
$2,500 per year (Rohrbacher, 2010)
ECM No. 3 – DO
Probe Maintenance
Annual Replacement
Sensor Caps
$140 per cap (Hach, 2010)
General Hourly Average Staff
Rate Including Benefits
$70,000 per year or
$36.45 per hour
Boca Raton WWTP staff
interview
46
IV. METHODOLOGY
4.1 Identifying Specific Energy Conservation Measures
This paper analyzes the benefit of implementing three specific ECMs at wastewater treatment
facilities in southeast Florida by conducting a life-cycle cost analysis on each ECM. The ECMs that are
listed below will be analyzed for energy savings gained versus the capital cost and present value for change
in O&M costs associated with installing the ECM.
ECM No. 1 - Fine Bubble Diffusers
Implementation of ECM No. 1 - fine bubble diffusers results in increased aeration efficiency
compared to mechanical surface aeration, based on the amount of pounds of oxygen transferred to
wastewater per kilowatt-hour of electricity consumed (lb O2 / kWh). The plants considered in this analysis
currently utilize mechanical surface aeration, and in one case also medium-bubble diffusers.
ECM No. 2 – Turbo Blowers
Implementation of turbo blower technology results in greater efficiency compared to other blower
technologies due to better mechanical efficiencies, resulting in reduced electrical costs. The ECM No. 2
life cycle cost analysis scenario assumes that a fine bubble diffuser system with blowers of comparable
horsepower is already installed.
ECM No. 3 – Automatic DO Control Strategy
Implementation of automatic DO control strategy reduces electrical costs by matching blower
output to oxygen required. The ECM No. 3 life cycle cost analysis scenario assumes that a fine bubble
diffuser system and turbo blowers are already installed, but includes installation of DO probes, modulating
valves, flow meters, and other associate electrical and instrumentation costs.
4.2 Lifecycle Cost Analysis of ECMs
To complete a lifecycle cost analysis of each ECM, it is necessary to complete a preliminary
design of the aeration system at each plant and estimate the net present value of annual energy savings and
47
compares to the net present value of change in O&M costs and capital costs of the proposed ECMs. The
flow-chart below in Table 4.1 summarizes a step by step method used for completing the life cycle cost
analysis:
48
Table 4.1 – Summary of Methodology
1. Obtain and input historical plant operating data, estimate sludge yield (Spreadsheet 1.1)
2. Project future and design flowrates and loadings (Spreadsheet 1.2)
3. Calculate O2 requirement air flowrates for design flows and loadings (Spreadsheet 2.0 - 2.3)
4. Size and layout process air piping (Spreadsheet 3.1.)
5. Estimate friction loss through air piping and create system curve (Spreadsheet 3.2 and 3.3)
6. Size blowers using available manufacturer’s blower performance data (Spreadsheet 3.4)
7. Insert equation for system curve into Spreadsheet 2.0 and calculate required power and energy
consumption of blowers for ECM Nos. 1 through 3 (return to Spreadsheets 2.0 - 2.3)
8. Complete capital cost estimate (Spreadsheets 4.0 - 4.7)
9. Complete O&M and foregone capital cost estimate (Spreadsheet 5.0 and 5.1)
10. Estimate existing energy use under current plant configuration for comparison with Energy use
under ECM Nos. 1 through 3 (Spreadsheet 6.0)
11. Complete a Life Cycle Cost Analysis for ECM Nos. 1 through 3 and calculate payback.
(Spreadsheets 6.1 and 6.2)
49
The sections that follow detail the methodology used in the model. Screenshots of the actual
model spreadsheets are provided from the City of Boca Raton WWTP analysis for example. In the
screenshots, fields highlighted in grey indicate user input fields. All other fields are output fields.
4.2.1 Historical Plant Data
Available historical plant data is required for the model. It is typical to use at minimum two years
of historical data for determining design flowrates and loadings to a plant (Tchobanoglous et al., 2003).
Three years of historical data were used for this analysis to account for erratic seasonal flow and storm data
characteristic of the south Florida region. Historical data for the study facilities are gleaned from available
monthly operating reports and annual operating reports. Historical plant data is input into Spreadsheet 1. 1
of the model. A screenshot of Spreadsheet 1.1 is provided as Figure 4.1.
Figure 4.1 – Spreadsheet 1. 1 – Influent-Effluent Specifier
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The fields in grey receive direct user input based on the years of historical data used, and the fields
in white are calculated based on the data input. In the case of the City of Boca Raton shown in Figure 4.1,
the future flowrates and loadings are predicted based on design plant flowrate as established per the
existing permit, and 2011-2031 average flowrate which is predicted in Spreadsheet 1.2.
4.2.2 Estimating Yield
One of the most common problems with obtaining accurate historical plant data is encountered
with obtaining accurate sludge wastage rates, which is a model input in Spreadsheet 1.1 (effluent waste
activated sludge volatile suspended solids, or EFF WAS VSS). WAS flow is the most commonly
mismeasured and misreported variable due to the relatively small magnitude of WAS flow compared to
other flows, and inadequate measurement instrumentation. The result is that significant uncertainty is often
associated with WAS when using historical data for modeling purposes (Melcer et al., 2003). Since the
wastage is a key variable in calculating oxygen requirement and hence effecting predicted energy
consumption, historical wastage data available from each of the plants was compared to typical values to
check their reasonableness. Typical sludge yield values are obtained using Figure 8-7a and 8-7b from
(Tchobanoglous et al., 2003) and are provided as Figure 4.2 and Figure 4.3, below:
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Figure 4.2 – Typical Yield for Primarily Treated Domestic Wastewater (Tchobanoglous et al., 2003)
Figure 4.3 – Typical Yield for Raw Domestic Wastewater (Tchobanoglous et al., 2003)
In addition, (Dold, 2007) indicated in Figures 4.2 and 4.3 above, particularly the typical yield
curve for raw wastewater from Figure 4.3, may significantly underpredict sludge yield. Equation (4) is
used to predict typical sludge yield for each plant. The results of observed yields compared to estimated
yields using both the (Tchobanoglous et al., 2003) typical yield curves and Equation (4) adapted from
(Dold, 2007) are provided in Table 4.2.
lb VSS produced = BOD5 (4) lb BOD5 influent COD
Where COD = typical value of 2.04 for raw influent, or 1.87 for settled influent
BOD5
fUS = unbiodgradable soluble fraction, typical value of 0.05 for raw influent, or 0.08 for settled influent
fUP = unbiodegradable particulate fraction, typical value of 0.13 for raw influent, or 0.08 for settled influent
Y = 0.47 mg VSS/mg COD
Θx = SRT
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f = 0.2
fCV,P = 1.6 mg COD / mg VSS
b = 0.24 x 1.029 T – 20 d-1 (5)
Where T = temperature (°C)
Table 4.2 – Boca Raton WWTP– Incremental Life-Cycle Cost Analysis
INF BOD
INF TSS
WAS VSS
Avg SRT Obs.
(Metcalf & Eddy,
2003) Est.
(Dold,2007) Est.
Plant Type (lb/day) (lb/day) (lb/day) (days) Yield Yield Yield Boca Raton Primary Eff 18,410 9,592 10,659 3.9 0.58 0.58 0.53 N Broward Raw Inf 54,818 71,891 27,444 3.7 0.50 0.91 0.63 Plantation Primary Eff 8,615 6,737 2,849 30 0.33 0.35 0.30
Table 4.2 demonstrates that both Boca Raton WWTP and Plantation Regional WWTP yields are
both within 10% of (Tchobanoglous et al., 2003) and (Dold, 2007). However, the observed yield at
Broward County North Regional WWTP is significantly lower than typical values. For this reason, the
(Dold, 2007) predicted yield of 0.63 is used to determine EFF WAS VSS in place of historical values due
to an apparent reporting error in sludge values. The model user must determine the viability of existing
sludge wastage data and make these calculations outside of the spreadsheets.
4.2.3 Project Future Flows and Loadings
It is necessary to project future 20-year flowrates and loadings for designing capital improvements
and estimating future energy use over the 20-year design horizon. The flowrates and loadings projected at
the end of the 20-year period are used to design capital improvements, and the average flowrate and
loading over the 20-year period is used to estimate average annual energy use. Future loadings are
extrapolated on a linear basis from the three year data on a flow-proportional basis using the equation
below:
Future Predicted Loading Rate = Three Year Average Loading Rate x Future Predicted Flowrate (6) Three Year Average Flowrate
53
Future predicted loading rates are input into Spreadsheet 1.2 of the model. A screenshot of
Spreadsheet 1.2 is provided as Figure 4.4.
Figure 4.4 – Spreadsheet 1. 2 – Flow Projection
4.2.4 Calculate Oxygen Requirement and Required Air Flowrates
The amount of oxygen required to achieve current treatment standards was determined using the
following equations:
1) Oxygen required by the activated sludge process is determined by the following equation,
Ro = So – S – 1.42PX,Bio + 4.33x(NOx) = SOTR (7)
Where Ro = total oxygen required, lb/d
54
So = influent substrate concentration, lb/d (of bCOD)
S = effluent substrate concentration lb/d (of bCOD)
SOTR = Standard Oxygen Transfer Required (lb 02/d)
NOx = ammonia oxidized, lb/d
bCOD = 1.6 x BOD5
BOD5 = 1.16 x CBOD5
(Adapted f/ eq. 8-17, Tchobanoglous et al., 2003)
PX,Bio = WAS VSS – WAS nbVSS (8)
Where WAS VSS = biomass as VSS wasted ( lb/d)
WAS nbVSS = nonbiodegradeable VSS in influent
(Adapted f/ eq. 8-17, Tchobanoglous et al., 2003)
Typical WAS nbVSS = 0.13 for raw influent, 0.08 for primary clarified influent (Dold, 2007)
The Boca Raton WWTP and the Broward County North Regional WWTP do not currently fully
nitrify. As such, WAS VSS must be estimated (as opposed to using historical measured values) for
predicting oxygen consumption for the three facilities. Conversely, the Plantation Regional WWTP
currently completely nitrifies. Therefore, WAS VSS for a non-nitrifying condition at that plant must be
estimated. In these cases, Equation (4) presented in Section 4.2.1 is used to predict yield.
2) The amount of ammonia oxidized, or NOx by the activated sludge process is determined by the
following equation:
NOx = TKN – Ne – 0.12(PX,Bio) (9)
Where TKN = influent TKN, lb/d
Ne = effluent NH4-N, lb/d
(Adapted f/ eq. 8-18, Tchobanoglous et al., 2003)
55
An alternate and more conservative method for calculating oxygen required for the purpose of
determining maximum aeration system capacity is often employed in the design and operation of WWTPs
as opposed to the method of Equation (7). The method in equation (10) below assumes that all CBOD5 that
does not leave the liquid stream treatment process through the plant effluent is oxidized in the activated
sludge process. However, at all plants a significant portion of CBOD5 and nitrogen is not oxidized in the
activated sludge process and exits the liquids stream process in the form of volatile suspended solids (VSS)
in the waste activated sludge (WAS) stream, or PX,Bio as denoted in equation (8) (Schroedel et al., 2010).
The CBOD5 is then further broken down in digesters or other solids stream treatment processes. This
method is not used for this paper as it results in a very conservative and more expensive design of aeration
systems.
Ro = (So – S eff) + 4.57(TKNo – TKN eff) = SOTR (10)
The oxygen required that is estimated by equation (7) must then be adjusted to reflect the effect of
multiple external factors on oxygen transfer in the system such as salinity-surface tension (beta factor),
temperature, elevation, diffuser depth, target oxygen level, and the effects of mixing intensity and tank
geometry. The actual oxygen transfer required, or AOTR, is determined by the following expression:
(11)
Where AOTR = actual oxygen transfer rate under field conditions, lb 02/hr
SOTR = standard oxygen transfer rate in clean water at 20° C, zero DO, lb 02/hr
β = salinity-surface tension correction factor, 0.99 (Mueller et al., 2002)
CŚ,T,H = average dissolved oxygen saturation concentration in clean water in aeration tank at
temp. T and altitude H, mg/L:
(12)
CS,T,H =oxygen saturation concentration in clean water at temp. T and altitude H, mg/L
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Pd = pressure at the depth of air release, psi
Patm,H = atmospheric pressure at altitude H, psi
Pw, mid depth = water column pressure at mid depth, above point of air release, psi
CL = operating oxygen concentration, mg/L
Cs,20 = dissolved oxygen saturation concentration in clean water at 20° C and 1 atm, mg/L
T = operating temperature, ° C
α = oxygen transfer correction factor (values taken from Rosso, 2005)
F = fouling factor (values taken from Rosso, 2005)
τ = Oxygen saturation temperature correction factor of water
τ = 4.08x10-4(T2) – 3.82x10-2(T) + 1.6 (from Figure 3.6.1) (13)
(Adapted f/ eq. 5-55, Tchobanoglous et al., 2003; and eq. 2.53, Mueller et al., 2002)
To calculate the estimated power draw for diffused aeration, an air flowrate must be calculated
based on the SOTR determined in equation (11) that will provide the amount of oxygen transfer required at
design conditions. The series of equations presented below are used to calculate the power requirement for
diffused aeration:
Air Flowrate, SCFM = SOTR . (14) [(SOTE)(24 hr/d) (60 min/hr) (O2 ρ)]
Where SCFM = Standard Cubic Feet Per Minute
SOTE = Standard Oxygen Transfer Efficiency
O2 ρ = density of oxygen in volume of air, lb O2 / lb air
The SOTE is an observed value that varies with every diffuser. SOTE charts are typically
provided by the diffuser manufactuer. For this analysis, the Sanitaire – Silver Series II diffuser is assumed.
A best fit fourth order curve was applied to the SOTE data available from Sanitaire to obtain the equation
used in the model to estimate SOTE at each flowrate as demonstrated in Figure 4.5.
57
The energy use of each proposed ECM was calculated by assuming the air requirement for the
average annual flowrate and loading in the blower power equation for 365 days of continual operation.
Blower power is estimated using the power requirement for adiabatic compression equation.
(15)
Where Pw = power requirement of blower, hp
R = engineering gas constant for air, 53.3 ft.lb / lb air . °R
°R = °F + 459.67
T1 = Absolute inlet temperature, °R
P1 = absolute inlet pressure, psi
P2 = absolute outlet pressure, psi
n = 0.283 for air
550 = constant, 550 ft-lb / s-hp
e = efficiency
w = mass flowrate of air, lb/s = (SCFM) (ρair) / (60 seconds/minute) (16)
Where ρair = 0.0750 lb/cf (density of air at Standard Conditions, 68°F, 36% relative
humidity)
(Adapted f/ eq. 5-56b, Tchobanoglous et al., 2003)
The key assumptions used for ECM scenario Nos. 1 through 3 are detailed in previous sections
and are reiterated below.
Table 4.3 – Key Assumptions for ECMs
ECM No. Description DO Efficiency
ECM No. 1 Fine bubble diffusers 3 62%
ECM No. 2 Turbo blowers 3 72%
ECM No. 3 Automatic DO control 1.5 72%
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Spreadsheet 2.0 - Aeration Calculations – Global Parameters, is the main user input spreadsheet
for the aeration and airflow calculations. A screenshot of Spreadsheet 2.0 is provided as Figure 4.6.
Figure 4.5 – Sanitaire Silver Series II - SOTE Vs. SCFM per diffuser
59
Figure 4.6 – Spreadsheet 2.0 – Aeration Calculations – Global Parameters
Description of inputs for Spreadsheet 2.0 – Global Parameters
The numerous assumptions input into Spreadsheet 2.0 were discussed in Section 2.7, and are also
briefly discussed following Figure 4.6.
• Area Under Aeration Per Basin (ft2) – Existing area per aeration basins, used for calculating
volume and calculating minimum mixing requirement
• # of Basins Online – Average number of basins online at a given time over the 20 year study
period, used for calculating total volume
• Side Water Depth (ft) – depth from water surface elevation to basin bottom, used for calculating
total volume
• Diffuser Submergence (ft) – depth from water surface elevation to top of diffuser, typically 1 foot,
used in oxygen transfer calculations
60
• Equation for System Curve – the system curve is estimated in Spreadsheet 3.3, a second order
polynomial best fit curve is applied to the system curve and the first number of the equation is
insert here
• Number of Diffusers Per Basin – the number of diffusers is adjusted by the user to insure that the
maximum recommended airflow per diffuser is not exceeded under most conditions
• Site Elevation (feet above MSL) – elevation of site above mean sea level, used for oxygen transfer
calculations
• Minimum Mixing Requirements (scfm/ft2) – minimum recommended airflow to maintain adequate
mixing, 0.12 sfm per (Mueller et al., 2002)
• Minimum Flow Per Diffuser (scfm) – minimum recommended flow per diffusers (0.5 cfm /
diffuser for Sanitaire Silver Series II diffusers)
• Maximum Flow Per Diffuser (scfm) – maximum recommended flow per diffuser (3 cfm / diffuser
for Sanitaire Silver Series II diffusers)
• General Temperature (°C) – Average temperature of wastewater, used for oxygen transfer
calculations
• Beta (unitless) - Beta is a factor which reduces the predicted oxygen transfer efficiency of the
system based on total dissolved solids concentration effects
• Patm (psi) – Standard atmospheric pressure, 14.7 psi at sea level
• Patm (mid depth, ft wc/2/2.31(psi)) – Pressure at mid depth of water column between water
surface and top of diffuser)
• CstH (per App D for mech aer, mg/L) – Saturated DO concentration in water at 25°C, 14.7 psi
• CstH* (mg/L) – Average saturated DO concentration, assumed to be saturated DO concentration
at mid depth of water column between water surface and top of diffuser per (Metcalf & Eddy,
2003)
61
• Dens air (lb/cf) – density of air at standard conditions, (68°F, 14.7 psi, 36% relative humidity)
• Mass fraction O2 in air – fraction of oxygen in air at standard conditions, (68°F, 14.7 psi, 36%
relative humidity)
• Alpha – oxygen transfer correction factor for wastewater based on SRT per (Rosso et al., 2005)
• Alpha for complete nitrification - oxygen transfer correction factor for wastewater at SRT of 5
days
• Average or minimum SOTE – when “a” is input into this field, the oxygen transfer calculations
assume the average efficiency reported by the manufacturer, when “m” is input into this field, the
oxygen transfer calculations assume to minimum efficiency reported by the manufacturer
• Manual DO Control O2 (mg/L) – the average DO practically obtainable by using manual DO
control, 3.0 mg/L as determined in earlier sections
• Auto DO Control O2 (mg/L) – the average DO practically obtainable by using automatic DO
control, 1.5 mg/L as discussed in earlier sections
• MSC Blower Efficiency – the average total efficiency practically obtainable by using multi-stage
centrifugal blowers, 62% as discussed in earlier sections
• Turbo Blower Efficiency - the average total efficiency practically obtainable by using turbo
blowers, 72% as discussed in earlier sections
• O2 Concentration at Max Day (mg/L) – Allowable DO concentration at maximum day loading
conditions, 0.5 mg/L
• Pre-ECM Existing DO (mg/L) – Existing DO concentration prior to implementing proposed
ECMs at plants, varies by plant
• Y, (per Dold, 2007) – Sludge yield as measured by VSS, calculated using equation (4)
• Fup (Dold, 2007) – Unbiodegradable particulate fraction of influent wastewater, 0.08 for settled
influent and 0.13 for raw influent
62
• VSS/TSS (Tchobanoglous et al., 2003) – typical VSS/TSS ratio of 0.85
Description of Aeration Calculation Spreadsheets 2.1 – 2.3 – Aeration Calculations
Inputs into Spreadsheet 1.0 and Spreadsheet 2.0 feed into Spreadsheets 2.1 – Aeration Calculations –
Diffusers, Spreadsheet 2.2 – Aeration Calculations – Turbo Blowers, and Spreadsheet 2.3 – Aeration
Calculations – 1.5 mg/L DO Control. The first three columns of each spreadsheet are used as the basis for
calculating total air and horsepower required to satisfy the average daily flow and loading conditions over
the 20 year design period, using the methodology discussed earlier in this section. The horsepower
calculated in the first three columns of each spreadsheet are used as the basis for predicting energy savings
in Spreadsheet 6.1, where it is compared to existing horsepower usage. The remaining columns are used to
predict airflow at multiple design conditions such as minimum day, maximum month, and maximum day to
appropriately size the aeration system such as pipes, blowers, and number of diffusers so that capital cost
can then be estimated. It is necessary for the user to click the “Calculate SOTE” button in each spreadsheet,
which initiates a macro that iteratively solves for the SOTE through the diffusers at a given flowrate based
on manufacturer supplied SOTE curves. Screenshots of Spreadsheets 2.1 through 2.3 are provided as
Figures 4.7 through Figure 4.9.
Figure 4.7 – Spreadsheet 2.1 – Aeration Calculations – Diffusers
63
Figure 4.8 – Spreadsheet 2.2 – Aeration Calculations – Turbo Blowers
64
Figure 4.9 – Spreadsheet 2.3 – Aeration Calculations – DO Control
65
66
4.2.5 Size Process Air Piping
Process air piping is sized using the maximum day design air flow. Process air pipes are designed
to prevent velocities from exceeding the typical velocity ranges of 2,700 to 4,000 feet per minute (fpm) in
12 inch to 24 inch diameter piping, and 3,800 to 6,500 fpm in 30 inch to 60 inch piping (Tchobanoglous et
al., 2003). Exceptions are made for slight exceedances of the recommended velocities at peak day flows.
Once process air piping diameters have been appropriately sized and the air piping is laid out in a
preliminary design, the headloss through the system is estimated. To estimate the headloss through the
system, the flowrate of air moving through the system must be calculated. Because gasses that are
propelled through a blower turbine are compressed and heated, the air volume moving through the aeration
system is less than the air entering the system. The air moving through the aeration system is often referred
to as Actual Cubic Feet per Minute (ACFM). ACFM is converted from SCFM using the following
equation:
(17)
Where ACFM = Actual Cubic Feet Per Minute
SCFM = Standard Cubic Feet Per Minute (at Standard Conditions of 14.7 psia, 68°F and 36% RH)
TA = Actual Temperature (°F)
TS = Standard Temperature (68°F)
PA = Actual Pressure (psia)
PS = Standard Pressure (14.7 psia)
RHA = Actual Relative Humidity (%)
RHS = Standard Relative Humidity (36%)
VPA = Actual Saturation Water Vapor Pressure (psia)
VPS = Standard SaturationVapor Pressure (at Standard Conditions of 14.7 psig, 68°F and 36%
RH)
(Stephenson and Nixon, 1986)
67
The saturation water vapor pressure is determined from observed values (Stephenson and Nixon,
1986). A fifth order polynomial curve is fit to the data to arrive at the equation used for determining
saturation water vapor pressure from 32°F to 308°F, and is given below:
VPT = 2.27x10-11 (T5) – 2.5x10-10 (T4) + 5.08x10-7 (T3) + 7.42x10-6 (T2) + 1.46x10-3 (T) + 0.016 (18)
Where VPT = Saturation Water Vapor Pressure at temperature T
T = Temperature (°F) Description of Spreadsheet 3.1 – System Design – Size Pipes
Spreadsheet 3.1 is used to size the pipes throughout the basin in accordance with the methodlogy
discussed in this section. In the case of Boca Raton WWTP, Spreadsheet 3.1.1 and Spreadsheet 3.1.2 are
required to size multiple sections. The user adjusts the pipe diameter for each section of pipe to remain
within the allowable velocities for Table 5-28 of (Tchobanoglous et al., 2003). Headloss should also be
considered when sizing pipes, oftentimes the pipe diameter corresponds to the upper end of the suggested
velocity range. However, the middle to lower velocity range may be recommended for particular sections
to mimimize headloss through the system while taking into account capital cost and constructability
concerns. The pipe diameters from Spreadsheet 3.1 are fed into Spreadsheet 3.2, where the system head
loss is calcualted. A screenshot of Spreadsheet 3.1 is provided as Figure 4.10.
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Figure 4.10 – Spreadsheet 3.1 – System Design – Size Pipes
4.2.6 Estimate Headloss Through Pipes and Create System Curve
Headloss through the proposed piping system is estimated at the design flow using the following
equations:
The Swamee-Jain Equation is used to estimate the Darcy Weisbach Friction factor;
(19)
69
Where f = Darcy-Wesibach friction factor (unitless)
ε = roughness height (ft) (0.00005 for stainless steel)
D = Pipe Diameter (ft)
Re = Reynold’s Number
(Lindeburg, 2003)
The Reynolds Number is calculated using the following equation:
Re (20)
Where Re = Reynold’s Number (unitless)
V = air velocity (ft/s)
L = Length of pipe (ft)
ν = kinematic viscosity at discharge temperature (ft2/s)
(Lindeburg, 2003)
Next, major headloss is calculated using the following equation:
(21)
Where hL major = major headloss (inches of water column) or (in w.c.)
f = Darcy-Weisbach friction factor (unitless)
D = Pipe Diameter (ft)
hi = Velocity head of air (in w.c.)
(Metcalf & Eddy, 2003)
Minor headloss is calculated by summing up the friction loss K factors for each fitting or valve at
each different velocity head and adding to the major headloss.
(22)
70
Where hL minor = minor headloss (in. w.c.)
Ki = friction loss coefficient
hi = Velocity head of air (in w.c.)
(Lindeburg, 2003)
Static headloss is the headloss due to static water pressure, which is directly related to the depth of the
water in the aeration basins above the fine bubble diffusers:
(23)
Where hL static = static headloss (in w.c.)
ddiffusers = depth of diffusers below water surface (inches)
(Lindeburg, 2003)
The total system headloss is the sum of major, minor, and static headlosses:
(24)
The process air piping system curve for the system is created based on the headloss and maximum design
flow from the equation above. The maximum design flow required by the process is the maximum day
design flow. Various points are plotted to create the system curve based on the following equation.
hL d (25)
Where hL I = headloss at velocity vi
vi = velocity vi (fps)
vd = design velocity(fps)
hL d = headloss at velocity vd
(adapted from Lindeburg, 2003)
Description of Spreadsheet 3.2 – System Design – Estimate Losses Through Pipes and Spreadsheet 3.3 –
System Design – System Curve
Spreadsheet 3.2 is used to calculate system head loss in accordance with the methodlogy discussed
in this section. Once the system pressures and air flowrates are determined, the corresponding energy
71
requirements for supplying process air to meet the flowrate and pressure requirements can be determined
for ECM No. 1 through 3. Spreadsheet 3.3 is used to determine the system curve and the best fit second
order polynomial equation for user input back into Spreadsheet 2.0. A screenshot of Spreadsheet 3.2 and
Spreadsheet 3.3 are provided as Figure 4.11 and Figure 4.12, respectively.
Figure 4.11 – Spreadsheet 3.2 – System Design – Estimate Losses Through Pipes
72
73
Figure 4.12 – Spreadsheet 3.3 – System Design – System Curve
Note: The curve in Figure 4.12 results in an exact fit because psi is predicted based on equation (25)
4.2.7 Sizing Blowers
Once the maximum day design flow and associated headloss are determined, the blowers are
sized. The maximum day design flow and associated headloss through the system define the design point
for the blowers. Extreme weather conditions effect oxygen transfer and must be considered when sizing
blowers. Because hotter air expands and has less oxygen per unit volume, the blower system must provide
provide a high enough flowrate to supply adequate oxygen for the hottest summer day. Also effecting
oxygen transfer is humidity, because moisture contained in a unit volume of air displaces oxygen. The
following historical weather data was researched for the study area of West Palm Beach, Florida and is
assumed for all models.
74
Table 4.4 – Extreme Weather Design Conditions
Data Source Parameter Value
ASHRAE Extreme (1%) Conditions
for WPB (Kuehn et al., 2005) Design Temperature (Wet Bulb) (°F): 80
NOAA Records for West Palm
Beach from www.ncdc.noaa.gov
(NESDIS, 2010)
Maximum Temperature (°F): 101
Resulting relative humidity derived
from ASHRAE Psychrometric Chart
No. 1, Normal Temperature (Kuehn
et al., 2005)
Resulting Relative Humidity*: 41%
Once the extreme weather design conditions are determined, it is necessary to determine the
design blower flowrate and pressure based on the extreme hot weather event. The required air flowrate for
the design condition as determined by equation (14) is adjusted for extreme hot weather conditions using
the formula below:
(26)
Where ICFM = Inlet Cubic Feet Per Minute
SCFM = Standard Cubic Feet Per Minute (at Standard Conditions of 14.7 psia, 68°F and 36% RH)
TA = Design Temperature (101 °F)
TS = Standard Temperature (68°F)
PA = Design Pressure (psia) (varies depending on specific design)
PS = Standard Pressure (14.7 psia)
RHA = Design Relative Humidity (41 %)
RHS = Standard Relative Humidity (36%)
VPA = Actual Saturation Water Vapor Pressure (0.9781 psi at 101 °F)
VPS = Standard SaturationVapor Pressure (at Std Conditions of 14.7 psig, 68°F and 36% RH)
(Stephenson and Nixon, 1986)
75
Equation (26) is used to specify the total capacity required from the blower system. Each facility blower
system design is subject to the following criteria:
• Turbo blowers currently available on the market are generally limited to a maximum of
approximately 7,000 SCFM capacity.
• To comply with EPA Class I Reliability standards, it is necessary to have at least two blower units
available, so that if one or more are out of service the oxygen requirement can still be satisfied
with the remaining blowers (US EPA, 1974). Three or more units are typical.
• The blower system must be capable of providing the entire range of required airflows with
minimal gaps in coverage, from maximum day to minimum day design flow. This is generally
accomplished by providing at least one blower that is 60% to 80% capacity of larger blowers.
• Turbo blowers generally have the ability to turn down air flow to 50 percent or greater, which
reduces or eliminates gaps in air coverage. However, installing “small” and “large” blower units
to further reduce concern of providing entire range of required airflows should be provided if
feasible. For multi-stage centrifugal blowers, this is a necessity.
• The blower system must be sized so that with the largest unit out of service, it can still satisfy the
oxygen requirement of the system. To reduce capital costs and the need for extraneous blower
capacity, it is typical to allow the system to satisfy maximum month average daily loading with
one unit out of service, and maximum day loading with all units in service (Mueller et al., 2002).
• To reduce capital costs and the need for extraneous blower capacity, it is typical to allow the
system to provide 0.5 to 1.0 mg/L of oxygen concentration in the aeration basins during maximum
day loadings, as opposed to the typical 2 mg/L DO for lesser loadings (Mueller et al., 2002).
• The blower system must also be able to provide the minimum amount of air required for mixing,
which can be greater than the minimum day design loading oxygen requirements (Mueller et al.,
2002) .
The blower nameplate design pressure also must be adjusted to account for extreme weather conditions
using the following equation:
76
(27)
Where EAP = Equivalent Air Pressure (psi)
TA = Design Temperature (101 °F)
TS = Standard Temperature (68°F)
PI = Inlet Pressure (psia) (varies depending on specific design)
PS = Standard Pressure (14.7 psia)
(Stephenson and Nixon, 1986)
Spreadsheet 3.4 is used to size the blower requirements for the system in accordance with the
methodlogy discussed in this section. A screenshot of Spreadsheet 3.4 is provided as Figure 4.13.
77
Figure 4.13 – Spreadsheet 3.4 – System Design – Blower Design
4.2.8 Estimate Capital Cost
Following design of the proposed ECMs, a capital cost estimate of construction is completed. The
methodology and assumptions used for estimating the capital cost of the project are discussed fully in
Section 3. Spreadsheet 4.0 is used to summarize the results of capital cost estimating for the various
components of the project including demolition, blowers, diffusers, structural, mechanical, instrumentation,
and electrical. Spreadsheets 4.1 through 4.7 are provided for each facility investigated in the appendix. A
screenshot of the summary Spreadsheet 4.0 is provided as Figure 4.14.
78
Figure 4.14 – Spreadsheet 4.0 – Cost Estimate - Summary
4.2.9 Estimate O&M and Foregone Capital Replacement Costs
The methodology and assumptions used for estimating the O&M and foregone capital replacement
costs of the project are discussed fully in Section 3. Spreadsheet 5.0 is used to summarize the results of
O&M and foregone capital replacement costs. Spreadsheet 5.1 is provided for each facility investigated in
the appendix. A screenshot of the summary Spreadsheet 5.0 is provided as Figure 4.15.
79
Figure 4.15 – Spreadsheet 5.0 – O&M Costs
4.2.10 Energy Baseline – Estimated Energy Consumption of Existing Mechanical Aerators
The energy usage baseline is defined herein as the current energy usage of the existing system.
For mechanical aeration, the energy usage baseline is determined for comparison to predicted diffused
aeration performance. Electric motors are commonly oversized by approximately 10%, and are
approximately 90% efficient. For this reason, it is common to take nameplate horsepower at face value for
calculating power draw in energy calculations (Schroedel et al., 2010). However, if more detailed
information is available regarding a motor’s operation such as amperage draw measured in the field, a more
80
accurate estimate of energy consumption can be obtained using the three phase electric power equation.
Three phase electric power is calculated via the following equation:
P = V x I x 3 x PF (28)
Where P = Power consumed (kWh)
V = line voltage (kW)
I = average line current of 3 legs
PF = power factor
(Schreodel et al., 2010)
Voltage for the equipment at the plants investigated is 3-phase, 480 volts, which is typical of most
treatment plant equipment. Amperage was measured on each phase of the mechanical aerators of each plant
using portable or integral ammeters. The power factor is the ratio of actual power to apparent power, and
reflects the principle that electric motors draw more power than they use and return a portion of the power
to the source (Schroedel et al., 2010). In the absence of actual power factors, it was neccesary to determine
a practical power factor value to assume for the eqipment studied. The power factors for premium
efficiency, squirrel cage induction 1,200 rpm motors from four prominent manufacturer’s were researched
and are detailed in Table 4.5 below to derive an average power factor at full load and half load.
Table 4.5 – Power Factor
Manufacturer PF At Full Load PF at 1/2 Load
U.S. Motors 81.4 NA
ABB 82.5 73
Reliance 85.6 77.3
GE 87.5 NA
Average 84.2 75.1 To estimate existing energy usage at each plant, amp draws from each mechanical aerator were
obtained and energy usage was estimated based on equation (28). Spreadsheet 6.0 is used to estimate the
existing energy useage baseline in accordance with the methodology discussed in this section. A
screenshot of Spreadsheet 6.0 is provided as Figure 4.16.
81
4.2.11 Complete Life Cycle Cost Analysis
The methodology and assumptions used for completing a life-cycle cost analysis are discussed in
Section 3. Spreadsheet 6.0 is used to input life cycle assumptions and the energy baseline data discussed in
Section 4.3.9. A screenshot of the life cycle cost analuysis input Spreadsheet 6.0 is provided as Figure
4.16.
Figure 4.16 – Spreadsheet 6.0 – Lifecycle Cost Analysis Inputs
The energy savings analyses are were conducted on all ECM Nos. 1 thorugh 3 for three level of
treatment scenarios, “Current Treatment”, “Partial Nitrification (NOx)” and “Complete NOx”. Each
scenario is described below:
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1. Current Treatment – Two of the three mechanically aerated plants in this study do not currently
achieve full nitrification. Accordingly, the Current Treatment scenario demonstrates the potential
energy savings assuming that the activated sludge process continues to only partially nitrify, with
the existing DO levels for the City of Boca Raton WWTP and the Broward County North
Regional WWTP. It is unlikely that the current treatment low DO levels would be designed for
were the plant upgraded. Rather they would be designed to provide the capability for a higher DO
(Partial Nitrification scenario) or provide the capability to aerate to the point of full nitrfication
(Complete Nitrification scenario). However, the purpose of the Current Treatment scenario is to
demonstrate the baseline cost savings that are achieved by only varying the method of oxygen
delivery, without the additional benefits achieved by raising the oxygen concentration and/or
achieving full nitrification of ammonia.
2. Partial Nitrification – Similar to the Current Treatment scenario, the Partial Nitrification
comparison demonstrates the potential energy savings assuming that the activated sludge process
continues to only partially nitrify. Unlike the Current Treatment scenario, DO concentration is
raised beyond the existing low level baseline to a value more typical of fine bubble diffused
aeration systems (1.5 to 3.0 mg/L). The Partial Nitrification scenario is the most likely treatment
standard that a plant renovation would be designed to achieve.
3. Complete Nitrification – The Complete Nitrification comparison demonstrates the potential energy
savings assuming that hypothetical diffused aeration system is designed to achieve complete
nitrification. Although the plants are not currently required to provide nitrification, leading to
denitrification, it is likely that an upgrade to the plant’s aeration system would be designed with
the flexibility to provide complete nitrification in anticipation of medium to long term changes in
regulatory requirements.
Spreadsheets 6.1.1 through 6.1.3 are used to summarize the results of the life cycle cost analysis
for each ECM and level of treatment scenario combination. The only variable between Spreadsheets 6.1.1
through 6.1.3 are the capital costs. Spreadsheet 6.1.1 calculates the estimated payback based on the median
predicted capital cost from Spreadsheet 4.0, and Spreadsheet 6.1.2 and 6.1.3 calculate the estimated
83
payback based on the Class 4 AACE Cost Estimate low range of -20% and high range of + 30%,
respectively. Payback is computed by calculating the time at which the net present value of annual
estimated energy savings for each ECM and scenario is equal to the net present value of O&M and capital
costs. The user must activate the iterative calculation macro by clicking on the “Calculate Payback”
button. A screenshot of the life cycle cost analysis input Spreadsheet 6.1.1 is provided as Figure 4.17. The
life cycle cost analysis summary for Spreadsheets 6.1.1 through 6.1.3 is provided in Spreadsheet 6.1.2. A
screenshot of the life cycle cost analysis summary Spreadsheet 6.2 is provided as Figure 4.18.
Figure 4.17 – Spreadsheet 6.1.1 – Life Cycle Cost Analysis
84
Figure 4.18 – Spreadsheet 6.2 – Incremental Life Cycle Cost Analysis Summary
85
86
4.2.12 Model Accuracy Verification
The model was checked against real world conditions to verify it’s accuracy. Actual case study
data from other plants measuring electricity usage of mechanical aeration before replacement, and data
measuring electricity usage following implementation of fine bubble was not available. However, data
available from the Broward County North Regional WWTP was used to measure side by side efficiency of
mechanical aeration versus fine bubble diffused aeration, and also data to measure the model’s accuracy at
predicting average airflow rates and energy use.
Daily average electricity use and air flowrates from August through October 2010 were available
for Module C which was converted from mechanical air to fine bubble diffused air with multistage
centrifugal blowers and limited automatic DO control in 2005. The Module C basins are nearly identical to
the Module A and Module B tanks. The available daily flowrate and loading data for Module C was input
into the model, and the predicted air flowrate and horsepower was compared with measured air flowrate
and horsepower for the three month period. The following assumptions and considerations were made to
calibrate the model to the conditions at Module C for verification:
• Detailed data on daily average air flowrate, horsepower, influent flowrate, and CBOD5 loading
was available for August through October, 2010
• Actual daily influent CBOD5 loading data for August through October 2010 was assumed
• Daily CBOD5 effluent was assumed as 5 mg/L
• Daily TKN data for August through October 2010 was not available, so the 2004-2006 TKN
influent average of 33.7 mg/L was assumed
• An SRT of 3.7 days was assumed, similar to the 2004 – 2006 average of Modules A and B
• Wastewater temperature is assumed to vary each month based on the average ambient monthly
temperature provided by NOAA for West Palm Beach, FL. Yield is calculated per (Dold, 2007)
and is effected by the varying temperature, which results in a slightly lower yield and PX,Bio than
average conditions.
• Record drawings and design documents from the 2005 aeration system improvement project
(Hazen and Sawyer, 2005) were examined and are provided in the appendix. The module C basin
87
has the same approximate footprint as Module A and Module B. Sidewater depth is 15.33 feet and
diffuser submergence is 14.33 feet. Each basin has 3,330 Sanitaire – Silver Series II diffusers for
a total of 13,320 diffusers.
• The Module C system was designed with a limited DO control system. Each basin has a single
membrane type DO probe at the midpoint of the basin that is used to throttle a single MOV valve
to each basin. The system has a DO setpoint of 2.0 mg/L. Because DO data is not available for
the August through October 2010 timeframe, a range of 1.5 to 2.5 mg/L DO are checked in the
model verification.
• Three (3) 500 horsepower multistage centrifugal blowers provide air to Module C. The
dimensions of the piping system were ascertained from the record drawings for the 2005 aeration
system improvement project and used to determine the system curve and headloss for input into
the model verification.
• The airflow through the aeration system at Module C is partially comprised of foul air from the
headworks (approximately 8,000 cfm), which is conveyed to the aeration basins for odor control.
A low pressure centrifugal FRP fan blows the air from the headworks into the aeration system. A
detailed analysis of the FRP fan capacity was not completed. It is assumed that the foul air
arriving at the blower suction is similar to ambient pressure for blower power calculations.
As an example, a screenshot of a week of data from the North Broward Regional WWTP that was used
to verify model accuracy is provided as Figure 4.19.
88
Figure 4.19 – Model Verification - Week of August 8, 2010
89
The bottom rows of the Figure 4.19 demonstrate how the model predicted air flowrate and
horsepower correlate to measured values for the week of August 8 through August 13, 2010. It is apparent
that the method used to estimate horsepower, based on SCFM and efficiency assumption of 62% for multi-
stage centrifugal blowers, correlates well to the actual horsepower supplied at the Broward County
Northern Region WWTP – Module C. The values marked within the red box of Figure 4.19 show that the
model accurately predicts horsepower based on equation (19) and key efficiency assumptions, predicting a
daily average of 805 horsepower versus 803 horsepower measured.
It is also apparent from Figure 4.19 that the air flowrate and horsepower measured at Module C do
not correlate well with the model predicted values when considered on a day by day basis. It appears that
the Module C aeration system does not respond to fluctuations in influent loading as Equation (4) would
suggest. Figure 4.20 demonstrates the variability of predicted SCFM versus the much more confined
variation of measured SCFM.
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
1‐Aug 31‐Aug 30‐Sep 30‐Oct
SCFM
Date
Measured SCFM
Predicted SCFM
Linear (Measured SCFM)
Linear (Predicted SCFM)
Figure 4.20 – Predicted SCFM vs. Measured SCFM
90
Although predicted air flowrate and horsepower do not correlate well on a daily basis, Figure 4.20
and Table 4.6, below, demonstrate that when averaged over the three month timeframe from August
through October, 2010, a good correlation is apparent, with a SCFM predicted to SCFM measured value
ratio of 98%, and a horsepower predicted to horsepower measured value ratio of 100%.
Table 4.6 – Predicted SCFM vs. Standard Oxygen Requirement based on Loading
Key Assumptions Comparison of Model’s Predicted Values to
Actual Measured Values
DO (mg/L)
Yield (lb VSS/ lb BOD)
Efficiency (%) Alpha
SCFM Predicted/Measured (%)
hp Predicted/Measured (%)
2.5 0.62 62% 0.43 98% 100%
Under the key assumptions listed in Table 4.6, a good correlation is apparent. However, the key
variables that were developed for this paper are based on typical expected values of DO, yield, efficiency,
and alpha. The actual values at the Broward County North Regional WWTP – Module C were not able to
be verified. To determine the effects of variability of these key assumptions on the models accuracy, a
sensitivity analysis of the key assumptions was completed. Table 4.7 demonstrates that the model results
are most sensitive to variation of DO and alpha.
Table 4.7 – Model Verification Sensitivity Analysis
Parameter Value SCFM Predict /
Measured hp Predicted /Measured
DO (mg/L)
1.5 81% 79%
2 88% 89%
2.5 98% 100%
Yield (lb VSS / lb
BOD)
0.57 102% 106%
0.62 98% 100%
0.67 93% 94%
Efficiency (%)
57% - 108%
62% - 100%
67% - 92%
(Table 4.7 continued on next page)
91
Parameter Value SCFM Predict /
Measured hp Predicted /Measured (Table 4.7 continued)
Alpha
0.38 113% 120%
0.43 98% 100%
0.48 85% 84%
Daily average electricity usage was available for August through October, 2010 for mechanically
aerated Module A and Module B and compared to energy usage of Module C, presented in Table 4.8.
Table 4.8 demonstrates that all three modules are approximately equivalent in energy use over the three
month period on a hp/MGD basis. While this finding may seem contrary to this thesis’ assertion that
installation of fine bubble diffusers will improve the energy efficiency of treatment, it is important to note
that the treatment being supplied in Modules A and B are not equivalent to the level of treatment being
supplied in Module C. DO levels of 2.0 mg/L or higher are being supplied in Module C, and air is being
supplied beyond that required to satisfy carbonaceous oxygen demand to achieve complete nitrification.
Although Module C has fine bubble diffusers, it does not have the additional ECMs of turbo blowers and
automatic DO control with probes and valves in each zone with the capability to tightly control DO within
1.5 mg/L. Table 4.9 shows that using the assumptions in Table 4.6, a gain in efficiency of 4% is predicted,
matching relatively close to the measured gain in efficiency of 1% for the August to October 2010
timeframe (based on the key assumptions listed in Table 4.6).
Table 4.8 – Mechanically Aerated Module A, B, vs. Fine Bubble Aerated Module C Measured Energy
Usage Comparison
Module hp/MGD
Mechanically Aerated Module A 47.3
Mechanically Aerated Module B 45.7
Fine Bubble Aerated Module C 46.1
Actual % Efficiency Gain of Module
C vs. Module A/B for Aug – Oct 2010 1%
92
Table 4.9 – Model Efficiency Gain Prediction Vs. Actual Efficiency Gain Prediction
Technology Level of Treatment
Current hp (Mechanical Aeration) 1
Proposed hp (Fine Bubble
Diffused Air)
Predicted %
Efficiency Gain
Actual % Efficiency Gain of Module C vs. Module A/B for Aug –
Oct 2010
1. Fine Bubble Diffusers
Complete Nitrification 823 786 4% 1%
1. Projected hp assuming all aerators are on for each module
In summary, the model predictions appear to correlate reasonably well to the limited data available
from the Broward County North Regional WWTP for fine bubble diffused aeration energy, indicating that
the model is reasonably accurate at predicting average airflow rates and energy use. Broward County North
Regional WWTP provides a remarkably unique opportunity to measure the model’s accuracy due to the
side by side arrangement of mechanical aeration versus fine bubble diffused aeration in identical basins and
influent wastewater characteristics. Unfortunately similar information is not available at the Boca Raton
WWTP nor the Plantation Regional WWTP. The side by side measured efficiency of mechanical aeration
at Module A and Module B versus fine bubble diffused aeration at Module C was also compared, and
correlates reasonably well with the model. Variations in key assumptions can affect the model results as
demonstrated in Table 4.7. However, reasonable assumptions based on key assumption values in Table 4.6
demonstrate good correlation in this case and provide preliminary verification of the model’s relative
accuracy and precision. It is recommended that additional data sets and verification of key assumptions be
completed and used to verify the model.
93
V. PLANT ECM ASSESSMENT
The facilities shown in Table 5.1 are analyzed using the methodology discussed in previous
sections for ECM upgrades to the activated sludge process. The plants were chosen based on the common
factor that they all use a mechanically aerated conventional activated sludge treatment process.
Table 5.1 – Study Facility Summary
PLANT NAME CITY AERATION SYSTEM SUMMARY
Boca Raton WWTP Boca Raton, FL
17.5 MGD capacity plant, (3) 2.1 MG aeration basins each
with (3) 100-hp mechanical surface aerators. (3) multi-stage
centrifugal blowers provide peak season / high loading
supplemental aeration.
Broward Co North
Regional WWTP Pompano Beach, FL
95 MGD capacity plant with both mechanical and fine bubble
diffused aeration. Study focuses on (8) 2.2 MG aeration
basins each with (3) 100-hp mechanical surface aerators.
Plantation Regional
WWTP Plantation, FL
18.9 MGD capacity plant with (3) 1.1 MG aeration basins
each with (1) 125-hp and (2) 100-hp mechanical surface
aerators.
5.1 City of Boca Raton WWTP
5.1.1 Boca Raton WWTP - Existing Secondary Treatment
The Boca Raton WWTP utilizes the following liquid stream treatment processes; influent
screening and grit removal, primary clarification, a conventional activated sludge system with mechanical
aeration and limited medium-bubble diffused aeration, secondary clarification, chlorination, and high rate
filtration for producing reclaimed water. The secondary treatment process comprises three (3) 85-feet wide
94
by 255-feet long aeration basins with sidewater depth of 13 feet. Three (3) 100 hp mechanical surface
aerators normally provide air to each basin on a constant basis, with two of three basins in operation at any
given time. Additionally, supplemental aeration is typically provided by a medium-bubble diffuser system
in the first third of each basin during peak season / peak loading hours, approximately four hours per day.
Air is provided to the diffusers via one of three multi-stage centrifugal blowers. The details of the aeration
system at the Boca Raton WWTP are summarized in Table 5.2 through 5. 5.
Table 5.2 - Aeration Basin Characteristics
Description Unit Value
Type of Unit Conventional Activated Sludge No. of Basins 3 Basin Dimensions:
Width ft 85 Length ft 255 Side Water Depth ft 13
Volume (each) cf 281,775 Total Volume MG 6.32
Table 5.3 - Mechanical Aeration Characteristics
Description Unit Value No. of Aerators
Per Basin 3 Total 9
Mechanical Aerator Rating, each lbs-O2/hr 300 Total Mechanical Aeration Capacity lbs-O2/day 64,800
Table 5.4 - Diffused Aeration Characteristics
Description Unit Value Manufacturer Parkson Flex-a-Tube No. of Diffusers
Per Basin 860 Total 2,580 Diffuser Rating lbs-O2/hour 0.674
Oxygen Transfer Capacity lbs-O2/day 13,911 Total Oxygen Transfer Capacity lbs-O2/day 41,730
95
Table 5.5 - Blower Characteristics
Description Unit Value Manufacturer Gardner Denver / Hoffman No. of Units 3 Type Multi-Stage Centrifugal Air Flow (each) scfm 4,000 Horsepower hp 200
(Hazen and Sawyer (2), 2007)
5.1.2 Boca Raton WWTP –Influent and Effluent Water Quality
Water quality data for the Boca Raton WWTP was gleaned from the 2007-2009 monthly operating
reports and is presented in Table 5.6 througuh 5.8, below. The data was adjusted to the average study
period flow (2011 to 2031) based on predicted population increase in the plant service boundaries which
were gleaned and interpolated from a 2001 South Florida Water Management District (SFWMD)
Consumptive Use Permit for the Boca Raton WWTP, and are used for the purposes of predicting average
energy consumption of the 20-year design horizon. Also, the data was adjusted to the plant design flow of
17.5 MGD which was used for designing the capital improvements. The CBOD5 loading data for the Boca
Raton WWTP following the primary clarifier process was not available. Primary clarifier removal rates are
typically 25 to 40 percent of BOD and 50 to 70 percent of TSS (Tchobanoglous et al., 2003). A
conservative value of 25 percent CBOD5 removal and 50 percent TSS removal was assumed and applied to
the City of Boca Raton raw influent loading rates. The data that was used for analysis of the Boca Raton
WWTP’s activated sludge treatment process and is presented in Tables 5.6 through 5.8 below.
Table 5.6 – Boca Raton WWTP – Design Influent/Effluent Based on 2007-2009 Flow/Loading Data
Loading Condition
Inf Flow
(MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS (lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Avg DO (lbs)
Avg SRT
(days) Min Day 9.72 6,433 4,180 84 1,370 2,277 419
ADF 13.98 15,870 9,592 333 10,659 4,153 1,104 0.50 3.91 MMADF 15.73 20,223 12,267 496 14,054 4,956 1,554 Max Day 21.02 28,204 35,070 968 17,200 6,596 1,972
96
Table 5.7 – Boca Raton WWTP – Design Influent/Effluent Adjusted to Est. 2011-2031 Avg Flowrate
Loading Condition
Inf Flow (MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS (lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 10.12 6,695 4,350 87 1,426 2,369 436 ADF 14.55 16,516 9,983 347 11,093 4,322 1,149
MMADF 16.37 21,046 12,766 516 14,626 5,158 1,618 Max Day 21.87 29,351 36,497 1,008 17,900 6,865 2,053
Table 5.8 – Boca Raton WWTP – Design Influent/Effluent Adjusted to Design Flow
Loading Condition
Inf Flow (MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS (lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 12.16 8,051 5,231 105 1,715 2,849 524 ADF 17.50 19,861 12,004 417 13,339 5,197 1,382
MMADF 19.69 25,308 15,351 621 17,587 6,202 1,945 Max Day 26.30 35,295 43,888 1,212 21,525 8,255 2,468
5.1.3 Boca Raton WWTP – Proposed ECM Design
Each ECM is cumulative and cannot be installed without the installation of the prior ECM. For
example, ECM No. 2 – Turbo Blowers cannot be installed without prior installation of ECM No. 1 – Fine
Bubble Diffusers (refer to Figure 1.10).
ECM No. 1 - Fine Bubble Diffusers –To install membrane fine bubble diffusers, it is necessary to
demolish the existing diffusers and mechanical aerators. Each basin is divided into three zones, and each
zone will be fitted with a grid of 1,167 diffusers, for a total of 9 grids and 10,500 diffusers. ECM No. 1
also requires the demolition of the existing concrete blower canopy structure and blowers, and the
construction of a new blower building with (1) 200-hp and (3) 300 hp multi-stage centrifugal blowers. It is
assumed that the nearby existing motor control center (MCC) room has adequate capacity to support the
three blowers since three 300-hp blowers and three 100-hp mechanical surface aerator starters that are
being removed from the nearby MCC exceed the horsepower of the proposed improvements. Although the
existing blowers are housed under an open air blower shelter, it is common to store blowers indoors for
protection from heat and extreme weather. Therefore, the existing blower shelter will be demolished and
replaced with a dedicated blower building.
97
ECM No. 2 – Turbo Blowers – ECM No. 2 entails installing (1) 200-hp and (3) 300-hp more
efficient turbo blowers in place of the multi-stage centrifugal blowers proposed under ECM No. 1.
ECM No. 3 – Automatic DO Control Strategy – Dissolved oxygen probes and transmitters will be
installed at each zone for a total of nine probes and six transmitters. Motor-operated modulating valves
(MOVs) and venturi flow meters will be installed on the aeration piping of each grid, to control flow to
each basin based on the DO level signal from the probe, for a total of nine MOVs and nine venturi flow
meters. A programmable logic control (PLC) unit will be installed in the blower building to control the
modulating valves and blowers based on DO and air flowrate measurement.
The preliminary design drawings for the proposed ECMs at the Boca Raton WWTP are provided
in Appendix A.
5.1.4 Boca Raton WWTP - Results and Discussion
The Boca Raton WWTP does not currently achieve full nitrification, as the average ammonia
concentration in the secondary effluent for the 2007-2009 was 9.8 mg/L and the historical average DO level
in the aeration basins was 0.5 mg/L. Accordingly, the Current Treatment scenario demonstrates the
potential energy savings assuming that the activated sludge process continues to only partially nitrify, with
an average DO of 0.5 mg/L. The estimated life cycle costs and savings are presented in Table 5.9 and 5.10,
below. The detailed spreadsheet calculations for the analysis are attached in Appendix A.
Table 5.9 – Life Cycle Cost Analyses Estimated Costs
Plant Level of
Treatment
NPV of Change in
O&M Costs
NPV of Foregone Capital
Replacement Capital
Cost
NPV of Capital, O&M,
Foregone Capital
Boca Raton WWTP Partial Nitrification
- $161,857 -$1,558,926 $3,261,794 $1,541,011
Table 5.10 – Life Cycle Cost Analyses Estimated Savings
Plant Level of
Treatment
Power Reduction
(hp) % Eff. Gain
Ann. Energy
Cost Savings
Energy Savings Net
Present Value
Payback (years) [range]
Boca Raton WWTP Partial Nitrification
209 37% $95,403 -$1,541,492 20 [11 to 37]
1. Range for AACE Class 4 cost estimate of -20% to + 30% of median estimate shown in brackets
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Figure 5.1 demonstrates the payback of implementing ECM Nos. 1 through 3 at the Boca Raton
WWTP. The point where the lines cross is the payback point, or the point at which the sum of O&M,
energy, and capital costs for ECM No. 1 through 3 become cost beneficial compared maintaining operation
of the existing mechanical aeration system. Figure 5.1 also demonstrates the range of error for payback
based on the AACE Class 4 cost estimate range of -20% to +30%, with a minimum range of 11 years and a
maximum of beyond 20 years (37 years).
$0
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
$8,000,000
0 5 10 15 20 25
Presen
t Value
Worth
Years
Exist.
Partial Nitrification
‐20% Capital Cost
+30% Capital Cost
Figure 5.1 – Present Value Comparison of Existing Process Versus Proposed ECMs
Table 5.11 and Figure 5.2 indicate that the cumulative effects of the ECMs result in a median
estimated payback of 16 years under the Current Treatment Scenario, 20 years under the Partial
Nitrification scenario, and 31 years for the Complete Nitrification scenario. The paybacks for the Current
Treatment and Partial Nitrification scenarios are at or beneath the payback threshold of 20 years that most
plant managers consider to be an actionable threshold. The Complete Nitrification scenario is not below
the threshold, however still presents a considerable payback.
99
In an anaysis of the paybacks of each individual ECM, Table 5.11 reveals that the only ECM that
does not have a payback under 20 years is ECM No. 1 - Fine Bubble Diffusers. These results indicate that
once the Boca Raton WWTP clears the hurdle of the implementation of ECM No. 1, that implementation of
ECM Nos. 2 through 4 are very cost benefical even under the high capital cost estimate assumption for the
partial nitrification and complete nitrification scenarios.
Table 5.11 – Boca Raton WWTP– Incremental Life-Cycle Cost Analysis
Technology Level of Treatment % Eff. Gain
Avg. Daily
Energy Savings (kWh)
Ann. Energy
Cost Savings
($)
Payback (Low Est)
(Years)
Payback (Median
Est) (Years)
Payback (High Est)
(Years)
1. Fine Bubble
Diffusers
Cur. Treatment - 1.5 mg/L DO 38% 3,819 $97,588 5 12 24 Part. Nitrification - 3.0 mg/L DO 3% 261 $6,668 - - -
Complete Nitrification -17% -1,672 ($42,714) - - -
2. Turbo Blowers
Cur. Treatment - 1.5 mg/L DO 9% 858 $21,929 13 17 24 Part. Nitrification - 3.0 mg/L DO 14% 1,353 $34,557 8 10 14
Complete Nitrification 16% 1,621 $41,416 7 8 11
3. Auto DO Control - 1.5 mg/L
Cur. Treatment - 1.5 mg/L DO 0% 0 $0 - - - Part. Nitrification - 1.5 mg/L DO 21% 2,120 $54,179 5 7 9
Complete Nitrification 26% 2,604 $66,534 4 6 8
Total Cumulative
Cur. Treatment - 1.5 mg/L DO 47% 4,678 $119,517 9 16 28 Part. Nitrification - 1.5 mg/L DO 37% 3,734 $95,404 11 20 37
Complete Nitrification 26% 2,553 $65,235 17 31 67
(1) The Current Treatment scenario for ECM No. 3 is not applicable because there is no difference in any of the variables or assumptions for that scenario between the ECM No. 2 and ECM No. 3
100
‐20%
‐10%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1. Fine Bubble Diffusers
2. Turbo Blowers 3. Auto DO Control ‐1.5 mg/L
Total
Efficen
cy (%)
ECM
Current Treatment ‐ 0.5 mg/L
Partial Nitrification ‐ 1.5 mg/L
Complete NOx
Figure 5.2 – Boca Raton WWTP – Incremental Increase in Efficiency Per ECM
The results demonstrate that each successive ECM accumulates for a cumulative total
improvement in efficiency, resulting in predicted energy and cost savings. Figure 5.2 demonstrates the
contribution of each ECM to the total improvement of efficiency over the existing aeration system. For the
Boca Raton WWTP, it is apparent that implementation of ECM No. 1 actually results in a loss of efficiency
for the Partial and Complete Nitrification scenarios. It is important to reemphasize that this loss in
efficiency is due to the additional treatment benefits of providing higher dissolved oxygen and complete
nitrification and is not a like for like comparison of the efficiency of the proposed system to the existing.
A theoretical like for like comparison is provided under the Current Treatment scenario, where DO is
maintained at 0.5 mg/L and partial nitrification continues at the previous rate. Under the theoretical
Current Treatment scenario, great improvement efficiency is realized with the implementation of ECM No.
1 and for the total efficiency
101
5.1.5 Boca Raton WWTP - Sensitivity Analysis
Variables were isolated and manipulated in the model to determine their effects on the payback
results, which are demonstrated in Table 5.12 below.
Table 5.12 – Boca Raton WWTP – Payback Sensitivity Analysis
Payback
Case Current
Treatment Partial
Nitrification Complete
Nitrification Base 18 20 36
10% Capital Reduction 16 17 29
20% Capital Reduction 13 14 24
AEO High Electricity Growth of +0.25% 16 20 32
AEO Low Electricity Growth of -0.18% 15 20 30
$0.08 per kWh 13 17 27
$0.09 per kWh 12 15 23
CPI Inflation + 1% or Bond Rate - 1% 14 18 26
CPI Inflation - 1% or Bond Rate + 1% 17 23 40
+5% Turbo Blower Efficiency 14 18 25
-5% Turbo Blower Efficiency 17 23 43
2.0 mg/L DO 16 24 47
1.0 mg/L DO 16 17 24
The effects of capital cost reduction are explored to determine how the payback improves with the
effects of grants or error in the capital cost estimate. The Current Treatment and Partial Nitrification
scenarios reduce considerably with capital cost reduction. The Complete Nitrification scenario payback
also improves considerably but not close to the 20 year threshold.
The effects of variations in the rate of electricity inflation used in the model were investigated by
testing how the model responds to the AEO 2006 – 2011 Report Low Economic Growth and High
102
Economic Growth “side case” average electricity inflation rates detailed in Table 3.2. The effects of the
Low Oil Price and High Oil Price side cases were not tested because their effects on the upward and
downward rate of electricity inflation are less pronounced than the economic cases as demonstrated in
Figure 3.2 .
The effects of variations in the CPI inflation rate or bond rate are similar because they are both
used to determine the real interest rate used in equation (1) and equation (2) for the life cycle cost analyses.
An equivalent rise in the CPI Rate will have an identical effect to an equivalent drop in the bond rate, and
vice-versa.
The effects of an increase or decrease in turbo blower efficiency are tested because the average
turbo blower efficiency of 72 percent determined from (Rohrbacher et al., 2010) would likely vary on a
case by case basis.
The effects of a variation in DO levels is tested to determine the model’s sensitivity to variations
in plant DO level, which may not be able to be held an an average target level of 1.5 mg/L due to operator
or insrument error, or other practical limitations such as peak loadings or toxic slugs.
The ramifications of the sensitivity analysis and comparison to the other plants are further
discussed in Section 6.5.
5.2 Broward County North Regional WWTP
5.2.1 Broward County North Regional WWTP - Existing Secondary Treatment
The Broward County North Regional WWTP utilizes the following liquid stream treatment
processes; influent screening and grit removal, a conventional activated sludge system with mechanical
aerators or fine-bubble diffusers, secondary clarification, and then discharge via deep well injection or
ocean outfall discharge, or high rate filtration and chlorination for reclaimed water distribution. The plant
exerts a demand of approximately 133,000 kW, making it the largest single electricity user in Broward
County. The aeration basins comprise approximately half of this power demand (Bloetscher, 2011).
The secondary treatment process comprises five modules of aeration basins. Each module
contains four 75-feet wide by 255-feet long aeration basins with sidewater depth of 15.5 feet. Modules A,
B, and D are equipped with mechanical aerators, and fine bubble diffused aeration is equipped in modules
103
C and E. The focus of this study is on improvements to modules A and B, where three (3) 100 hp
mechanical surface aerators provide air to each mechanically aerated basin on a constant basis. The details
of the aeration system at the Broward County North Regional WWTP are summarized in Table 5.13 and
Table 5. 14.
Table 5.13 - Aeration Basin Characteristics – Modules A and B
Description Unit Value
Type of Unit Conventional Activated Sludge No. of Basins 8 Basin Dimensions:
Width ft 75 Length ft 255 Side Water Depth ft 15.5
Volume (each) cf 296,000 Total Volume MG 17.74
Table 5.14 - Mechanical Aeration Characteristics – Modules A and B
Description Unit Value No. of Aerators
Per Basin 3 Total 24
Mechanical Aerator Rating, each lbs-O2/hr 300 Total Mechanical Aeration Capacity lbs-O2/day 172,800
(Hazen and Sawyer (1), 2007)
5.2.2 Broward County North Regional WWTP –Influent and Effluent Water Quality
Water quality data for the Broward County North Regional WWTP was gleaned from the 2004-
2006 monthly operating reports and is presented in Table 5.15 through 5.17, below. More recent data was
not able to be obtained. The data was adjusted to the average study period flow (2011 to 2031) based on
predicted population increase in the service boundaries gleaned and interpolated from a 2011 Capacity
Analysis Report (CAR) completed by Hazen and Sawyer, P.C. for the plant, which is used for the purposes
of predicting average energy consumption of the 20-year design horizon. Also, the data was adjusted to the
current plant design flow of 95 MGD which was used for designing the capital improvements.
104
Table 5.15 – Broward Co. N. Regional WWTP – Design Influent/Effluent Based on 2004-2006
Loading Condition
Inf Flow
(MGD)
Inf CBOD5
(lbs)
Inf TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS(1)
( )
Inf TKN (lbs)
Eff NH3 (lbs)
Avg DO (lbs)
Avg SRT
(days) Min Day 14.21 1,994 10,522 510 1,457 4,707 1,011
ADF 37.20 47,257 71,891 1,599 34,536 10,458 3,268 1.0 3.7
MMADF 44.15 71,927 126,168 2,643 52,564 13,935 5,459 Yield
Max Day 56.72 180,246 733,683 6,810 131,724 15,516 8,453 0.63
(1) Calculated based on Yield, estimated per (Dold, 2007) method
Table 5.16 – Broward Co. N. Regional WWTP – Design Influent/Effluent Adjusted to Est. 2011-2031 Avg Flow
Loading Condition
Inf Flow
(MGD)
Inf CBOD5
(lbs)
Inf TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS(1)
(lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 15.94 2,236 11,800 572 1,634 5,279 1,134
ADF 41.72 52,998 80,624 1,793 38,731 11,729 3,665
MMADF 49.52 80,665 141,495 2,964 58,950 15,628 6,122
Max Day 63.61 202,143 822,813 7,638 147,726 17,401 9,480
Table 5.17 – Broward Co. N. Regional WWTP – Design Influent/Effluent Adjusted to Design Flow
Loading Condition
Inf Flow
(MGD)
Inf CBOD5
(lbs)
Inf TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS(1)
(lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 18.14 2,546 13,434 652 1,861 6,010 1,291
ADF 47.50 60,338 91,790 2,042 44,095 13,353 4,173
MMADF 56.37 91,836 161,090 3,375 67,114 17,792 6,970
Max Day 72.41 230,137 936,761 8,695 168,184 19,810 10,793
5.2.3 Broward County North Regional WWTP – Plant Specific Methodology Considerations
Number of Basins Normally In Service
The calculation for the amount of horsepower used and the number of basins in service for the
Broward County North Regional WWTP model is nuanced. Unlike the Boca Raton WWTP or the
Plantation Regional WWTP, which both typically have a fixed number of basins in service at all times,
monthly operating reports reveal that Broward County North Regional WWTP brings basins at Modules A
and B in and out of service as flow and loading change, with as little as 5 and as many as 8 basins in service
105
during the 2004-2006 data study period. It is important to consider that over the 2011 – 2031 model period,
basins will be taken on and offline as neccesary depending on flowrates and loadings through the plant, and
also for scheduled maintenance. To estimate the amount of basins and horsepower used in the model, the
number of basins online compared with the amount of flow through each basin were analyzed for the years
2004 through 2006, and extrapolated to the 2011-2031 study period to predict the average amount of basins
in service . The results of this analysis are presented in Table 5.18.
Table 5.18 – 2004-2006 # of Basins In Service vs. Flowrate
Condition Avg # of Basins in Service
Module A and B Flow (MGD) MGD Per Basin
Avg Day 6.3 36.3 5.8
2011-2031 Avg 7.2 41.7 5.8
Module D Energy Reduction
Module D is similar to Module A and B, except that the aerator in the first zone of each basin at
Module D is 150 hp capacity. Currently the Broward County North Regional WWTP typically operates
two of the four basins at Module D. Once Module A and Module B are brought online with fine bubble
diffused air, it will be practical for the Broward County North Regional WWTP to divert flow away from
the mechanically aerated Module D to Module A and B, or to the existing fine-bubble aerated Module C
and E to achieve improved treatment efficiency. The mechanical aerators that are no longer required to be
operated at Module D are a key source of energy savings for this analysis.
According to the most recent O&M Performance Report (Hazen and Sawyer (1), 2007), the
average flow to each basin is 5.6 MGD, with a design capacity of 7 MGD per basin. Conservatively
assuming 5.6 MGD through each basin, the fine-bubble aerated Modules A, B, C, and E should have
adequate capacity to treat 89.6 MGD of flow, or 84 MGD with one basin out of service. Given that the
projected average flow over the 2011-2031 design period is 83.4 MGD, Module D should be able to be
kept out of service for the majority of the time, providing spare aeration capacity as needed for peak
seasonal flows and loadings, and for growth in flows and loadings towards the end of the design period.
For this analysis, it is conservatively assumed that on avearge one of the four basins at Module D will
remain in service over the 2011-2031 timeframe, and the energy saved by bringing one basin out of service
106
is deducted from the projected energy use for implementing ECM Nos. 1 through 3. Since Module D is
assumed to be offline, for modeling puporses it is assumed that half of all flow and loading entering the
plant will be routed through Module A and B, with the other half routed to Module C and E. Table 5.19
below summarizes the calculation of the Module D Energy Reduction.
Table 5.19 – Projected Module D Energy Reduction
Parameter Value Unit
Typical flow through each basin per 2007 O&M Report 5.6 MGD
Number of basins per module 4 Basins
Number of basins per module A, B, C, and E 16 Basins
Total capacity Module A, B, C, and E 89.6 MGD
Total capacity of Module A, B, C, and E with one basin out of service 84 MGD
Projected average flow over 2011-2031 time period 83.4 MGD
Number of basins at Module D typically online 2 Basins
Number of basins at Module D assumed to be brought offline due to flow routed to fine-bubble aerated modules 1 Basin
Typical energy usage per basin at Module D according to Aug through Oct 2010 average daily data (to be deducted from projected energy use for ECM No. 1 through 3) 309 hp
5.2.4 Broward County North Regional WWTP – Proposed ECM Design
ECM No. 1 - Fine Bubble Diffusers –To install membrane fine bubble diffusers, the existing
mechanical aerators will need to be demolished. Each basin is divided into three zones, and each zone will
be fitted with a grid of 830 diffusers, for a total of 24 grids and 20,000 diffusers. ECM No. 1 also entails
the construction of a new blower building with (2) 200-hp and (6) 300 hp multi-stage centrifugal blowers.
It is assumed that the nearby existing motor control center (MCC) room has adequate capacity to support
the eight blowers since the twenty four (24) 100-hp mechanical surface aerators that are being removed
exceed the horsepower of the proposed improvements. Although the existing blowers are housed under an
open air blower shelter, it is common to store blowers indoors for protection from heat and extreme
weather. The existing blower shelter will be demolished and replaced with a blower building.
107
ECM No. 2 – Turbo Blowers – ECM No. 2 entails installing (2) 200-hp and (6) 300-hp more
efficient turbo blowers in place of the multi-stage centrifugal blowers proposed under ECM No. 1.
ECM No. 3 – Automatic DO Control Strategy – Dissolved oxygen probes and transmitters will be
installed at each zone for a total of twenty four probes and twelve transmitters. Motor-operated modulating
valves (MOVs) and venturi flow meters will be installed on the aeration piping of each grid, to control flow
to each basin based on the DO level signal from the probe, for a total of twenty four MOVs and twenty four
venturi flow meters. A programmable logic control (PLC) unit will be installed in the blower building to
control the modulating valves and blowers based on DO and air flowrate.
The preliminary design drawings for the proposed ECMs at the Broward County North Regional
WWTP are provided in Appendix B.
5.2.5 Broward County North Regional WWTP – Results and Discussion
The Broward County North Regional WWTP does not achieve full nitrification, as the average
ammonia concentration in the secondary effluent (from the entire plant, not just Modules A and B) for the
2004-2006 year was 10.8 mg/L and the historical average DO level is 1.0 mg/L. Accordingly, the Current
Treatment scenario demonstrates the potential energy savings assuming that the activated sludge process
continues to only partially nitrify, with an average DO of 1.0 mg/L. The estimated life cycle costs and
savings are presented in Table 5.20 and 5.21, below. The detailed spreadsheet calculations for the analysis
are attached in Appendix B.
Table 5.20 – Life Cycle Cost Analyses Estimated Costs
Conditions Level of
Treatment
NPV of Change in
O&M Costs
NPV of Foregone Capital
Replacement Capital
Cost
NPV of Capital, O&M,
Foregone Capital
Broward Co N Regional Broward WWTP
Partial Nitrification
-$194,519 - $3,035,109 $7,954,846 $4,725,218
108
Table 5.21 – Life Cycle Cost Analyses Estimated Savings
Condition Level of
Treatment
Power Reduction
(hp)
% Eff.
Gain
Ann. Energy
Cost Savings
Energy Savings Net
Present Value
Payback (years) [range]
Not Considering Module D
Partial Nitrification
434 29% $198,730 ($3,211,003) 33
[19 to 63]
Considering One Basin at Module D Out of Service
Partial Nitrification
743 50% $340,081 ($5,494,902) 17 [11 to 28]
Considering Module D Completely Out of Service
Partial Nitrification
1052 71% $481,432 ($7,778,801) 11 [7 to 18]
1. Range for AACE Class 4 cost estimate of -20% to + 30% of median estimate shown in brackets
Figure 5.3 and Figure 5.4 demonstrate the payback of implementing ECM Nos. 1 through 3 at the
Broward County North Regional WWTP considering one basin at Module D out of service, and not
considering Module D effects, respectively. The point where the lines cross is the payback point, or the
point at which the sum of O&M, energy, and capital costs for ECM No. 1 through 3 becomes cost
beneficial compared to the current operation. Figure 5.3 and 5.4 demonstrate the range of error for
payback based on the AACE Class 4 cost estimate range of -20% to +30%, with a minimum range of 11
and maximum range of beyond 20 years (28 years) for the consideration of one basin at Module D out of
service, and a minimum range or 19 years and a maxmum beyond 20 years (63 years) for no consideration
of Module D effects.
109
$0
$2,000,000
$4,000,000
$6,000,000
$8,000,000
$10,000,000
$12,000,000
$14,000,000
$16,000,000
$18,000,000
$20,000,000
0 5 10 15 20 25
Presen
t Value
Worth
Years
Exist.
Partial Nitrification
‐20% Capital Cost
+30% Capital Cost
Figure 5.3 – Present Value Comparison of Existing Process Versus Proposed ECMs
$0
$5,000,000
$10,000,000
$15,000,000
$20,000,000
$25,000,000
0 5 10 15 20 25
Presen
t Value
Worth
Years
Exist.
Partial Nitrification
‐20% Capital Cost
+30% Capital Cost
Figure 5.4 – Present Value Comparison of Existing Process Versus Proposed ECMs – No Consideration for Module D Effects
110
Table 5.22 and Figure 5.5 indicate that the cumulative effects of the ECMs result in a median
estimated payback of 15 years under the Current Treatment Scenario, 17 years under the Partial
Nitrification scenario, and 21 years for the Complete Nitrification scenario. In an anaysis of the paybacks
of each individual ECM, Table 5.20 reveals that the each individual ECM achieves a considerable payback
at or beneath the 20 year threshold, except for the ECM No. 1 Partial Nitrification and Complete
Nitrification Scenarios.
Table 5.22 – Broward Co. N. Regional WWTP – Incremental Life-Cycle Cost Analysis
Technology Level of Treatment % Eff. Gain
Avg. Daily
Energy Savings (kWh)
Ann. Energy
Cost Savings
($)
Payback (Low Est)
(Years)
Payback (Median
Est) (Years)
Payback (High Est)
(Years)
1. Fine Bubble
Diffusers
Cur. Treatment - 1.5 mg/L DO 45% 6472 $306,702 7 13 22
Part. Nitrification - 3.0 mg/L DO 12% -2310 $82,343 47 - -
Complete Nitrification -1% -5847 ($8,051) - - -
2. Turbo Blowers
Cur. Treatment - 1.5 mg/L DO 10% 2784 $71,123 9 12 16
Part. Nitrification - 3.0 mg/L DO 15% 4003 $102,284 6 7 10
Complete Nitrification 17% 4495 $114,839 5 7 9
3. Auto DO Control - 1.5
mg/L
Cur. Treatment - 1.5 mg/L DO 0% 0 $0 - - -
Part. Nitrification - 1.5 mg/L DO 23% 6084 $155,455 5 6 8
Complete Nitrification 26% 6871 $175,551 4 5 7
Total Cumulative
Cur. Treatment - 1.5 mg/L DO 56% 9255 $377,824 10 15 24
Part. Nitrification - 1.5 mg/L DO 50% 7778 $340,081 11 17 28
Complete Nitrification 42% 5518 $282,338 13 21 36
(1) The Current Treatment scenario for ECM No. 3 is not applicable because there is no difference in any of the variables or assumptions for that scenario between the ECM No. 2 and ECM No. 3
111
‐10%
0%
10%
20%
30%
40%
50%
60%
1. Fine Bubble Diffusers
2. Turbo Blowers 3. Auto DO Control ‐1.5 mg/L
Total
Incease in Efficen
cy (%
)
ECM
Current Treatment ‐ 1.0 mg/L
Current Treatment ‐ 1.5 mg/L
Complete NOx
Figure 5.5 – Broward Co. N. Regional WWTP – Incremental Increase in Efficiency Per ECM
The results demonstrate that each successive ECM accumulates for a cumulative total
improvement in efficiency, resulting in predicted energy and cost savings. Figure 5.5 demonstrates the
contribution of each ECM to the total improvement of efficiency over the existing aeration system. For the
Broward County North Regional WWTP, it is apparent that implementation of ECM No. 1 actually results
in a loss of efficiency for the Partial and Complete Nitrification scenarios similar to the Boca Raton
WWTP. It is important to reemphasize that this loss in efficiency is due to the additional treatment benefits
of providing higher dissolved oxygen and complete nitrification and is not a like for like comparison of the
efficiency of the proposed system to the existing. A theoretical like for like comparison is provided under
the Current Treatment scenario, where DO is maintained at 1.0 mg/L and partial nitrification continues at
the previous rate. Under the theoretical Current Treatment scenario, a great improvement efficiency is
realized with the implementation of ECM No. 1 and for the total efficiency
112
5.2.6 Broward County North Regional WWTP - Sensitivity Analysis
Variables were isolated and manipulated in the model to determine their effects on the payback
results, which are demonstrated in Table 5.23 below.
Table 5.23 – Broward Co. N. Regional WWTP – Payback Sensitivity Analysis
Payback
Case Current
Treatment Partial
Nitrification Complete
Nitrification Base 15 17 21
10% Capital Reduction 12 14 17
20% Capital Reduction 10 11 13
AEO High Electricity Growth of +0.25% 15 17 20
AEO Low Electricity Growth of -0.18% 15 17 21
$0.08 per kWh 13 14 18
$0.09 per kWh 11 13 16
CPI Inflation + 1% or Bond Rate - 1% 14 15 19
CPI Inflation - 1% or Bond Rate + 1% 16 19 24
+5% Turbo Blower Efficiency 14 15 18
-5% Turbo Blower Efficiency 16 19 25
2.0 mg/L DO 15 20 26
1.0 mg/L DO 15 15 17
All scenarios show reasonable paybacks, with most cases for the Current Treatment and Partial
Nitrification base cases at or beneath the typical 20 year threshold that plant managers consider the
actionable threshold. The results in Table 5.23 generally do not deviate greatly from the Base Case. This
indicates that the Life Cycle Cost Analysis and Payback Analysis for the Broward County North Regional
WWTP are less sensitive to certain variable input parameters than the Boca Raton WWTP. This is due to
the the smaller relative effect of each change on the analysis at lower paybacks. Refer to Section 5.1.5 for a
discussion of the other parameters tested for sensitivity analysis which are similar between facilities
113
studied. The ramifications of the sensitivity analysis and comparison to the other plants are further
discussed in Section 6.5.
5.3 Plantation Regional WWTP
5.3.1 Plantation Regional WWTP - Existing Secondary Treatment
The Plantation Regional WWTP utilizes the following liquid stream treatment processes; influent
screening and grit removal, primary clarifiers, a conventional activated sludge system with mechanical
aerators, secondary clarification, and then deep well injection. The secondary treatment process comprises
three 65-feet wide by 195-feet long aeration basins with sidewater depth of 12 feet. One (1) 125-hp and
two (2) 100 hp mechanical surface aerators normally provide air to each basin on a constant basis, with all
basins normally in operation. One of the two 100-hp mechanical aerators is typically operating at a low
speed during the winter season when DO is able to be maintained with less power. The details of the
aeration system at the Broward County North Regional WWTP are summarized in Table 5.24 and Table
5.25.
Table 5.24 - Aeration Basin Characteristics
Description Unit Value
Type of Unit Conventional Activated Sludge No. of Basins 3 Basin Dimensions:
Width ft 65 Length ft 195 Side Water Depth ft 12
Volume (each) cf 152,100 Total Volume MG 3.41
Table 5.25 - Mechanical Aeration Characteristics
Description Unit Value No. of Aerators
Per Basin (1) 125 hp and (2) 100-hp Total (3) 125 hp and (6) 100-hp
(Hazen and Sawyer, 2004)
5.3.2 Plantation Regional WWTP – Influent and Effluent Water Quality
Water quality data for the Plantation Regional WWTP was gleaned from the 2007-2009 monthly
operating reports and is presented in Table 5.26 through 5.28, below. The data was adjusted to the average
114
study period flow (2011 to 2031) based on predicted population increase in the service boundaries gleaned
and interpolated from a 2011 Capacity Analysis Report (CAR) for the plant, which is used for the purposes
of predicting average energy consumption of the 20-year design horizon (Hazen and Sawyer, 2011). Also,
the data was adjusted to the plant design flow of 18.9 MGD which was used for designing the capital
improvements.
Table 5.26 – Plantation Regional WWTP – Design Influent/Effluent Based on 2007-2009 Flow/Loading Data
Loading Condition
Inf Flow
(MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS
(lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Avg DO (lbs)
Avg SRT
(days) Min Day 9.52 3,359 3,974 74 2,278 1,370 0
ADF 14.21 7,427 6,737 173 2,849 1,861 0 1.5 30.0
MMADF 16.06 11,614 10,131 256 3,263 2,237 0
Max Day 21.88 22,580 61,358 500 4,159 2,992 0
Table 5.27 – Plantation Regional WWTP – Design Influent/Effluent Adjusted to Est. 2011-2031 Avg Flow
Loading Condition
Inf Flow (MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS
(lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 10.44 3,682 4,356 81 2,498 1,502 0
ADF 15.58 8,142 7,385 190 3,123 2,040 0
MMADF 17.60 12,732 11,106 281 3,577 2,453 0
Max Day 23.99 24,754 67,264 548 4,559 3,280 0
Table 5.28 – Plantation Regional WWTP – Design Influent/Effluent Adjusted to Design Flow
Loading Condition
Inf Flow (MGD)
Pri. Eff CBOD5
(lbs)
Pri. Eff TSS (lbs)
Eff CBOD5
(lbs)
Eff WAS VSS
(lbs)
Inf TKN (lbs)
Eff NH3 (lbs)
Min Day 12.66 4,467 5,285 99 3,030 1,823 0
ADF 18.90 9,879 8,961 230 3,789 2,475 0
MMADF 21.36 15,448 13,474 341 4,340 2,976 0
Max Day 29.11 30,033 81,609 665 5,531 3,979 0
115
5.3.3 Plantation Regional WWTP – Proposed ECM Design
ECM No. 1 - Fine Bubble Diffusers –To install membrane fine bubble diffusers, the existing
diffusers and mechanical aerators will need to be demolished. Each basin is divided into three zones, and
each zone will be fitted with a grid of 667 diffusers, for a total of 9 grids and 2,000 diffusers. ECM No. 1
also entails the construction of a new blower building with (1) 200-hp and (3) 300 hp multi-stage
centrifugal blowers. It is assumed that the nearby existing motor control center (MCC) room has adequate
capacity to support the four blowers since the six 100-hp and three 125-hp mechanical surface aerator
starters that are being removed from the nearby Motor Control Center are of approximate equivalent power
capacity to the proposed improvements.
ECM No. 2 – Turbo Blowers – ECM No. 2 entails installing (1) 200-hp and (3) 300-hp more
efficient turbo blowers in place of the multi-stage centrifugal blowers proposed under ECM No. 1.
ECM No. 3 – Automatic DO Control Strategy – Dissolved oxygen probes and transmitters will be
installed at each zone for a total of nine probes and six transmitters. Motor-operated modulating valves
(MOVs) and venturi flow meters will be installed on the aeration piping of each grid, to control flow to
each basin based on the DO level signal from the probe, for a total of nine MOVs and nine venturi flow
meters. A programmable logic control (PLC) unit will be installed in the blower building to control the
modulating valves and blowers based on DO and air flowrate measurement.
The preliminary design drawings for the proposed ECMs at the Plantation Regional WWTP are
provided in Appendix C.
5.3.4 Plantation Regional WWTP – Results and Discussion
The Plantation Regional WWTP currently achieves full nitrification, as the average ammonia
concentration in the secondary effluent is less than 0.5 mg/L and DO is typically mainatined at 1.5 mg/L.
Accordingly, the Current Treatment scenario for the Plantation Regional WWTP case demonstrates the
potential energy savings assuming that the activated sludge process continues to completely nitrify, with an
average DO of 1.5 mg/L. The estimated life cycle costs and savings are presented in Table 5.29 and 5.30,
below. The detailed spreadsheet calculations for the analysis are attached in Appendix C.
116
Table 5.29 – Life Cycle Cost Analyses Estimated Costs
Plant Level of
Treatment
NPV of Change in
O&M Costs
NPV of Foregone Capital
Replacement Capital
Cost
NPV of Capital, O&M,
Foregone Capital
Plantation Regional WWTP
Complete Nitrification
-$146,489 -$1,034,902 $3,099,083 $1,917,692
Table 5.30 – Life Cycle Cost Analyses Estimated Savings
Plant Level of
Treatment
Power Reduction
(hp) % Eff. Gain
Ann. Energy
Cost Savings
Energy Savings Net
Present Value
Payback (years) [range]
Plantation Regional WWTP
Complete Nitrification
580 70% $265,401 ($4,288,241) 8 [6 to 13]
1. Range for AACE Class 4 cost estimate of -20% to + 30% of median estimate shown in brackets
Figure 5.6 demonstrates the payback of implementing ECM Nos. 1 through 3 at the Plantation
Regional WWTP. The point where the lines cross is the payback point, or the point at which the sum of
O&M, energy, and capital costs for ECM No. 1 through 3 become cost beneficial compared to maintaining
operation of the existing mechanical aeration system. Figure 5.6 demonstrates the range of error for
payback based on the AACE Class 4 cost estimate range of -20% to +30%, with a minimum range of 6
years and a maximum of 13 years.
117
$0
$2,000,000
$4,000,000
$6,000,000
$8,000,000
$10,000,000
$12,000,000
0 5 10 15 20 25 30
Presen
t Value
Worth
Years
Existing Treatment.
Proposed Upgrade
‐20% Capital Cost
+30% Capital Cost
Figure 5.6 – Present Value Comparison of Existing Process Versus Proposed ECMs
Table 5.31 and Figure 5.7 indicate that the cumulative effects of the ECMs result in a median
estimated payback of 8 years under the Current Treatment Scenario and 13 years under the Complete
Nitrification Scenario (essentially the same scenarios from a cumulative perspective). A payback of 7
years results under the Partial Nitrification scenario which assumes that 8 mg/L of ammonia remains in the
effluent. In an analysis of the paybacks of each individual ECM, Table 5.31 reveals that the each
individual ECM achieves a considerable payback near or below the 20 year threshold, except for the ECM
No. 2.
118
Table 5.31 – Plantation Regional WWTP – Incremental Life-Cycle Cost Analysis
Technology Level of Treatment % Eff. Gain
Avg. Daily
Energy Savings (kWh)
Ann. Energy
Cost Savings
($)
Payback (Low Est)
(Years)
Payback (Median
Est) (Years)
Payback (High Est)
(Years)
1. Fine Bubble
Diffusers
Cur. Treatment - 1.5 mg/L DO 65% 9663 $246,886 4 6 10 Part. Nitrification - 3.0 mg/L DO 72% 10658 $272,309 4 6 9
Complete Nitrification 53% 7910 $202,091 5 8 12
2. Turbo Blowers
Cur. Treatment - 1.5 mg/L DO 5% 725 $18,515 18 24 34 Part. Nitrification - 3.0 mg/L DO -1% -79 -$2,020 - - -
Complete Nitrification 7% 968 $24,736 12 16 21
3. Auto DO Control - 1.5 mg/L
Cur. Treatment - 1.5 mg/L DO 0% 0 $0 - - - Part. Nitrification - 1.5 mg/L DO 8% 1152 $29,422 7 9 12
Complete Nitrification 10% 1510 $38,573 6 8 10
Total Cumulative
Cur. Treatment - 1.5 mg/L DO 70% 10387 $265,401 6 8 13 Part. Nitrification - 1.5 mg/L DO 79% 11730 $299,711 5 7 11
Complete Nitrification 70% 10387 $265,401 6 8 13
1) The Current Treatment scenario for ECM No. 3 is not applicable because there is no difference in any of the variables or assumptions for that scenario between the ECM No. 2 and ECM No. 3
‐10%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1. Fine Bubble Diffusers 2. Turbo Blowers 3. Auto DO Control ‐ 1.5 mg/L
Total
Increase in Efficen
cy (%
)
ECM
Current Treatment ‐ 0.5 mg/L
Partial Nitrification ‐ 1.5 mg/L
Complete NOx
Figure 5.7 – Plantation Regional WWTP – Incremental Increase in Efficiency Per ECM
119
The results demonstrate that each successive ECM accumulates for a cumulative total
improvement in efficiency, resulting in predicted energy and cost savings. Figure 5.7 demonstrates the
contribution of each ECM to the total improvement of efficiency over the existing aeration system.
5.3.5 Plantation Regional WWTP - Sensitivity Analysis
Variables were isolated and manipulated in the model to determine their effects on the payback
results, which are demonstrated in Table 5.32 below.
Table 5.32 – Plantation Regional WWTP – Payback Sensitivity Analysis
Payback (Years)
Case Current
Treatment Partial
Nitrification Complete
Nitrification Base 8 7 8
10% Capital Reduction 7 6 7
20% Capital Reduction 6 5 6
AEO High Electricity Growth of +0.25% 8 7 8
AEO Low Electricity Growth of -0.18% 8 7 8
$0.08 per kWh 7 6 7
$0.09 per kWh 6 6 6
CPI Inflation + 1% or Bond Rate - 1% 8 7 8
CPI Inflation - 1% or Bond Rate + 1% 9 8 9
+5% Turbo Blower Efficiency 8 7 8
-5% Turbo Blower Efficiency 9 7 9
2.0 mg/L DO 8 8 9
1.0 mg/L DO 8 7 8
The results in Table 5.32 generally do not deviate greatly from the Base Case. This indicates that
the Life Cycle Cost Analysis and Payback Analysis for the Plantation Regional WWTP are generally less
sensitive to certain variable input parameters compared to the Boca Raton WWTP due to lower paybacks
being less sensitive to these changes in variables. Refer to Section 5.1.5 for a discussion of the other
120
parameters tested for sensitivity analysis which are similar between facilities studied. The ramifications of
the sensitivity analysis and comparison to the other plants are further discussed in Section 6.5.
121
VI. DISCUSSION AND COMPARISON OF RESULTS
The results of the analysis for each plant are compared and contrasted in this section.
6.1 Improvement of Efficiency Comparison and Analysis
Table 6.1 summarizes the results of the percent efficiency gain for each plant and scenario. Table
6.2 demonstrates the payback for each plant and scenario. The tables demonstrate that the Plantation
Regional WWTP is predicted to receive the highest proportional increase in efficiency and demonstrates
the most advantageous payback for each of the three plants.
Table 6.1 – Percent Efficiency Gain Per Plant and Scenario
% Eff. Gain
Boca Raton Broward Plantation Current Treatment 47% 56% 70%
Partial Nitrification - 1.5 mg/L DO 37% 50% 79%
Complete Nitrification 26% 42% 70%
Table 6.2 – Payback Per Plant and Scenario
Payback (Median Estimate) (Years)
Boca Raton Broward Plantation Current Treatment 16 15 8
Partial Nitrification - 1.5 mg/L DO 20 17 7
Complete Nitrification 31 21 8
To meaningfully compare the results of the analyses, it is important that the results are reflective
of the varying plant sizes and average flow through each plant, and the varying average loading through
each plant. Figure 6.1, Figure 6.2, and Figure 6.3 provide a comparison of the results and presents them on
a kWh / lb CBOD5, kWh / lb SOR, and also kWh / MGD basis, respectively.
122
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
Base Case Current Treatment Partial Nitrification Complete Nitrification
kWh / lb BOD Treated
Scenario
Boca Raton
North Broward
Plantation
Figure 6.1 – Improvement of Efficiency Per Scenario– kWh / lb BOD Treated
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Base Case Current Treatment Partial Nitrification Complete Nitrification
kWh / SO
R
Scenario
Boca Raton
North Broward
Plantation
Figure 6.2 – Improvement of Efficiency Per Scenario– kWh / SOR
123
0
200
400
600
800
1,000
1,200
Base Case Current Treatment Partial Nitrification Complete Nitrification
kWh / MGD
Scenario
Boca Raton
North Broward
Plantation
Figure 6.3 – Improvement of Efficiency Per Scenario– kWh / MGD Treated
The results demonstrate that prior to implementing ECMs, the Boca Raton WWTP and Broward
County North Regional WWTP demonstrate similar scales of efficiency. However, Plantation Regional
WWTP shows a scale of efficiency significantly greater that the other two plants on all three metrics for
Figure 6.1 through Figure 6.3. The main reason Plantation Regional WWTP is the least efficient prior to
ECM implementation is that the plant fully nitrifies, meaning that the plant fully oxidizes ammonia to
nitrate by aerating mixed liquor to a greater degree than the other plants, and also maintains higher solids
retention time (SRT) above 30 days. Although Plantation Regional WWTP is not required to fully nitrify
per the FDEP operation permit, they reportedly operate with increased DO and SRT levels to minimize
sludge yield and to reduce their solids loading to their digesters.
The results demonstrate that following implementation of the ECMs, each plants efficiency
improves greatly. However, a variable scale of efficiency following implementation of ECMs is apparent
between the plants on a kWh / lb of CBOD5 treated basis. Comparing the results on a SOR basis as shown
in Figure 6.2, as opposed to comparing the results on a kWh / lb CBOD5 or kWh / MGD basis as shown in
Figure 6.1 and Figure 6.3, results in the closest comparison of the three metrics. This is because the SOR
124
metric accounts for the varying degrees of nitrogen loading in addition to carbonaceous loading at each
plant, and also accounts for varying depths of diffuser submergence, temperature, DO, and alpha factors.
However, since the plants are not required to nitrify per their permit, the kWh / lb CBOD5 metric is still
meaningful as an efficiency measure.
Because the efficiency for the Broward County North Regional Plant was calculated with the side
assumption that a basin at Module D could be taken offline resulting in additional energy savings, the
metrics in Figure 6.1 through Figure 6.3 cannot be used as a baseline to measure plants outside of the study.
Removing the module D offline assumption from consideration results in an approximately equivalent
comparison in predicted energy use between each plant following implementation of the ECMs using the
kWh / lb SOR metric, as shown in Figure 6.4.
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Base Case Current Treatment Partial Nitrification Complete Nitrification
kWh / SO
R
Scenario
Boca Raton
North Broward
Plantation
Figure 6.4 – Improvement of Efficiency Per Scenario– kWh / SOR - (not considering Broward
County North Regional WWTP Module D Assumptions)
125
For this reason, the results of this study indicate that mechanically aerated plants implementing the
ECMs suggested in this study may roughly predict that they will achieve the average kWh / SOR treated
shown in Figure 6.4. The equation below formulates the estimated energy improvement.
Esaved = [kWhexisting - 0.10 ( SORavg)] x 8,760 hr/yr (29)
Where Esaved = predicted annual energy savings (kWh)
kWhexisting = plants exsting energy usage specific to activated sludge treatment process
SORavg = average predicted SOR folloing implementation of ECMs
6.2 Capital Cost Comparison and Analysis
The capital costs resulting from the analysis were also analyzed on a Capital Cost / MGD, Capital
Cost / lb CBOD5 treated, and Capital Cost / SOR basis. Table 6.3 demonstrates that all of the plants fall
within a similar capital cost range in proportion to plant capacity (in MGD). Figure 6.5 through 6.7 further
demonstrate that the Capital Cost / MGD appears to be the metric where the plants are most correlated.
126
Table 6.3 – Cumulative Capital Cost Per ECM
Boca Raton
N Broward Plantation Average Range
ECM No. 1 $2,486,493 $6,247,399 $2,428,616 - -
Capital Cost / ADF MGD Capacity $170,857 $149,738 $155,903 $158,833 14.1%
Capital Cost / lb BOD Treated $151 $118 $298 $189 153.0%
Capital Cost / SOR $31 $27 $44 $34 64.7%
ECM No. 1 and 2 $2,807,759 $6,889,931 $2,702,913 - -
Capital Cost / ADF MGD Capacity $192,933 $165,139 $173,512 $177,194 16.8%
Capital Cost / lb BOD Treated $170 $130 $332 $211 155.3%
Capital Cost / SOR $35 $30 $49 $38 66.3%
ECM No. 1 Through 3 $3,261,794 $7,954,846 $3,099,083 - -
Capital Cost / ADF MGD Capacity $224,132 $190,663 $198,943 $204,579 17.6%
Capital Cost / lb BOD Treated $197 $150 $381 $243 153.6%
Capital Cost / SOR $52 $43 $72 $56 67.4%
$0
$50,000
$100,000
$150,000
$200,000
$250,000
ECM No. 1 ECM No. 1 and 2 ECM No. 1 Through 3
Capital C
ost ($) / M
GD
High ‐ Boca Raton
Avg
Low ‐ Broward
Figure 6.5 – Range of Capital Cost / MGD Treated
127
$0
$50
$100
$150
$200
$250
$300
$350
$400
ECM No. 1 ECM No. 1 and 2 ECM No. 1 Through 3
Capital C
ost ($) / lb
CBO
D
High ‐ Plantation
Avg
Low ‐ Broward
Figure 6.6 – Range of Capital Cost / lb CBOD5 Treated
$0
$10
$20
$30
$40
$50
$60
$70
$80
ECM No. 1 ECM No. 1 and 2 ECM No. 1 Through 3
Capital C
ost ($) / SOR
High ‐ Plantation
Avg
Low ‐ Broward
Figure 6.7 – Range of Capital Cost / SOR
128
From Table 6.4 and Figures 6.5 through 6.7, it is apparent that the plants are within a closer range
on a Capital Cost / Avg MGD capacity basis compared to the Capital Cost / lb BOD or Capital Cost / SOR
basis. For this reason, the results of this study indicate that mechanically aerated plants implementing the
ECMs suggested in this study may estimate their capital cost based on the equation below.
Ccapital = Cavg x Qavg (30)
Where Ccapital = predicted capital cost for implmenting ECMs
Cavg = average Capital Cost / ADF MGD from Table 6.3
Qavg = average predicted flowrate over the design period
6.3 Payback Comparison and Analysis
The incremental payback for each ECM is compared in Figure 6.8, Figure 6.9, Figure 6.10, and
Figure 6.11.
0
5
10
15
Boca N Broward Plantation Boca N Broward Plantation Boca N Broward Plantation
Payback (years)
SCENARIO:
1. Fine Bubble Diffusers
Current Treatment Partial Nitrification Complete Nitrification
Over 100 YearsOver 100 Years
Figure 6.8 – ECM No. 1 - Fine Bubble Diffuser Payback Comparison
129
Comparing Figure 6.8 with Figure 6.9 and Figure 6.10, it is apparent that ECM No. 1 – Fine
Bubble Diffusers is the ECM resulting in the least advantageous incremental payback. This is related to the
fact that the capital cost involved with implementing ECM No. 1 is a major hurdle, comprising
approximately 75 to 85 percent of the total capital cost of each project. Another important trend to note in
Figure 6.8 is that for ECM No. 1, the payback decreases as the level of treatment increases from the current
treatment scenario partial nitrification scenario complete nitrification scenario. This is because the
amount of aeration and corresponding energy requirements increases as the level of treatment increases,
however the capital cost remains the same. The more cost advantageous incremental paybacks associated
with implementation of ECM No. 2 and ECM No. 3 cannot be realized without first implementing ECM
No. 1. Figure 6.9 and Figure 6.10 demonstrate that once ECM No. 1 is implemented, that ECM No. 2 and
ECM No. 3 are cost advantageous for most scenarios.
0
5
10
15
20
25
30
Boca N Broward Plantation Boca N Broward Plantation Boca N Broward Plantation
Payback (years)
SCENARIO:
2. Turbo Blowers
Current Treatment Partial Nitrification Complete Nitrification
N/A
Figure 6.9 – ECM No. 2 - Turbo Blower Payback Comparison
130
0
5
10
15
20
25
30
35
40
45
50
Boca N Broward Plantation Boca N Broward Plantation Boca N Broward Plantation
Payback (years)
SCENARIO:
3. Auto DO Control ‐ 1.5 mg/L
Current Treatment Partial Nitrification Complete Nitrification
N/A N/A
Figure 6.10 – ECM No. 3 - DO Control Payback Comparison
The trend of payback going from the current treatment scenario partial nitrification scenario
complete nitrification scenario for ECM No. 2 and No. 3 is decreasing. This decreasing trend may appear
counterintuitive, because as additional energy is required to achieve a higher DO going from the current
treatment scenario partial nitrification scenario, or as even more energy is required to provide additional
air for complete oxidation of ammonia going from the partial nitrification scenario complete nitrification
scenario, the amount of energy used increases which would result in more dollars spent on electricity.
However, the decreasing trend is explained by the fact that as the electricity required to supply additional
aeration increases, it also provides more opportunity for energy savings when compared to the alternative
of operating a fine bubble diffuser system without installing ECM No. 2 or ECM No. 3.
131
0
5
10
15
20
25
30
35
Boca N Broward Plantation Boca N Broward Plantation Boca N Broward Plantation
Payback (years)
SCENARIO:
Total (Cumulative)
Current Treatment Partial Nitrification Complete Nitrification
Figure 6.11 – ECM No. 1 through 3 - Cumulative Payback Comparison
The cumulative payback shown in Figure 6.11 demonstrates that excellent paybacks are obtained
for all three plants modeled for the current treatment and partial nitrification scenarios, with paybacks for
the complete nitrification scenarios below the 20 year range only for Plantation Regional WWTP.
Comparing Figures 6.8 through 6.11 clearly demonstrates that to achieve excellent paybacks at the three
plants studied, implementation of fine bubble diffusers is not enough. Installation of high efficiency
blowers and DO control systems are needed. This finding should be instructive for utilities considering
implementation of fine bubble diffusers but possibly not high efficiency blowers or DO control due to
capital constraints. Installation of ECM Nos. 2 and No. 3 leverages the benefit of the fine bubble diffusers
and will likely have a payback below 20 years at other facilities.
Finally, due the trends identified in the study related to predicted capital cost versus flowrate, and
predicted energy saved versus SOR, a general formula is presented to predict the payback of the ECM Nos.
1 through 3 at mechanically aerated activated sludge treatment processes.
132
NPV [Esaved * (Celectricity)] = NPV (∆O&M) + NPV Cforegone + Ccapital (31)
Where Ccapital = predicted capital cost for implmenting ECMs from Eq. (30)
Esaved = predicted annual energy savings (kWh) from Eq. (29)
Celectricity = current cost of electricity specific to each plant ($ / kWh)
∆O&M = change in O&M due to implementing ECMs specific to each plant
Cforegone = foregone capital replacement due to implementing ECMs specific to each
plant
NPV indicates to find Net Present Value over the 20 year time period using Eq. (1)
The above equation can then be iteratively solved for n (number of time periods in Present Worth
of a Geometric Gradient Series) to determine payback.
6.4 Sensitivity Analysis Comparison
The sensitivity analyses of the three plants were compared to identify parameters that are more or
less likely to affect the results. It should be noted that the greater the base case payback, the more
exaggerated are the effects of changing sensitive parameters such as in the case of Boca Raton WWTP.
The comparison in Table 6.4 indicates that one of the sensitive parameters affecting the payback is the
current price of electricity. A $.01 change in the price of electricity will alter the payback significantly.
Another sensitive parameter effecting payback is the capital cost. Capital cost may be offset by 10 percent
or more by public or private grants. Additionally, capital cost estimating methods are -20 / +30 percent
level of accuracy with a 10 percent contingency (Krause, 2010). Blower efficiencies are known to vary
from project to project. A 5 percent increase or decrease in efficiency appears to significantly affect the
payback.
Reductions in capital costs through public or private grants are obtainable. Locally, the Palm
Beach County – Southern Regional Water Reclamation Facility (SRWRF) recently received a $1.2 million
grant in 2009 from the US Department of Energy’s Efficiency and Conservation Block Grant toward the
construction of a biogas generator, which uses methane produced from the anaerobic digestion process to
power a generator to produce electricity as opposed to sending the methane to a waste gas flare. The grant
133
reduced the capital cost of total project delivery by 33%, which included the costs for a feasibility study,
engineering design, and construction. The grant was justified as a way to reduce dependence on fossil fuels
by reducing the facility’s energy draw by 14%, provide local job opportunities, and reduce greenhouse gas
emissions by approximately 1,250 metric tons annually (Palm Beach County, 2012).
Less sensitive parameters include inflation/bond rate. A 1 percent rise in inflation or drop in bond
rate can result in a marked improvement in payback. Conversely, a 1 percent drop in inflation or rise in
bond rate can result in a marked degradation of payback. However since inflation and bond rates generally
rise and fall in unison, the net effect can be expected to be minimial. Figure 6.12 illustrates the effects of
variation in the CPI inflation rate or bond rate on payback at the Boca Raton WWTP for example. Although
electricity prices are a sensitive parameter if changed, the AEO 2011 high and low economic growth
electricty predictions do no predict great variation in electricity prices which indicates a lower likelihood
that they would vary greatly from this analysis. However, a recent precipitous drop in southeast Florida
plant’s electrical bills from 2009 to 2010 of approximately 20 percent recently occurred, due to a reduction
in “pass through fuel charge” from FPL. Were fuel charges to rise again on a similar scale, paybacks
would be reduced for each plant from 2 to 5 years. Figure 6.13 illustrates the effects of a rise in electricity
price on payback at the Boca Raton WWTP for example.
134
Table 6.4 – Sensitivity Analysis Comparison
Change in Payback (years)
Boca1 N. Broward1 Plantation2
Base 20 17 8
10% Capital Reduction -3 -3 -1
20% Capital Reduction -6 -6 -2
AEO Report High Growth 0 0 0
AEO Report Low Growth 0 0 0
$0.08 per kWh -3 -3 -1
$0.09 per kWh -5 -5 -2
CPI Inflation + 1% or Bond Rate - 1% -2 -2 0
CPI Inflation - 1% or Bond Rate + 1% +3 +2 +1
+5% Turbo Blower Efficiency -2 -2 0
-5% Turbo Blower Efficiency +3 +2 +1
2.0 mg/L DO +4 +3 +1
1.0 mg/L DO -3 -2 0 (1) Considers partial nitrification case for the Boca Raton WWTP and the Broward County North Regional WWTP (2) Considers complete nitrification case for the Plantation Regional WWTP
135
$0
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
$8,000,000
$9,000,000
0 5 10 15 20 25
Presen
t Value
Worth
Years
Exist.
Partial Nitrification
CPI Inflation + 1% or Bond Rate ‐ 1%
CPI Inflation ‐1% or Bond Rate + 1%
Figure 6.12 – Sensitivity Analysis – Results of Variation in CPI Inflation or Bond Rate Assumptions
(Boca Raton WWTP Example)
$0
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
$8,000,000
$9,000,000
$10,000,000
0 5 10 15 20 25
Presen
t Value
Worth
Years
Exist ($0.07 per kwh).
Partial Nitrification
$0.09 per kwh
Figure 6.13 – Sensitivity Analysis – Results of Variation in Electricity Price (Boca Raton WWTP Example)
136
6.5 Total Savings And Regional Savings
The available energy saving for each plant, and total available energy savings, are tabulated in
Table 6.5. Table 6.5 demonstrates that on a regional basis, approximately 1.14 megawatts can be saved, or
approximately 10,000 megawatt-hours (MWh) can be saved per year if the ECMs were implemented at all
three plants. At the current price of $0.07 per kWh, 10,000 MWhs translates to $701K per year.
Table. 6.5 – Projected Energy Savings Related To Implementation of ECMs
Level of Treatment kWh kWh / Day
kWh / Year
% Eff. Gain
Boca Raton
Base Case 417 9,999 3,649,689 -
Part. Nitrification - 1.5 mg/L DO 261 6,265 2,286,780 37%
North Broward
Base Case 1,105 26,514 9,677,648 -
Part. Nitrification - 1.5 mg/L DO 550 13,204 4,819,453 50%
Plantation Base Case 620 14,880 5,431,323 -
Part. Nitrification - 1.5 mg/L DO 187 4,493 1,639,919 70%
Total Savings 1,143 27,432 10,012,507
6.6 Current Energy Intensity Discrepancy and Potential Operational Modifications at
Plantation Regional WWTP
Table 6.6 below demonstrates the difference in energy intensity between the plants prior to
implementing ECMs, (considering energy usage of aeration equipment only).
Table 6.6 – Current Aeration Energy Intensity Comparison
Aeration Energy Intensity (Current Usage) Boca Raton
N Broward Plantation
Power per carbonaceous load treated (kWh / lb CBOD5) 0.61 0.50 1.83
Factor 1.21 1.00 3.65
Power per total load treated (kWh / lb SOR) 0.19 0.17 0.33
Factor 1.14 1.00 2.00
Power per volume treated (kWh / MG) 687 635 955
Factor 1.08 1.00 1.50
137
From Table 6.6, it is apparent that the Broward County North Regional WWTP is currently the
most efficient of the three plants. On a power per carbonaceous load treated basis, it is apparent that
Plantation utilizes 265% additional energy than the most efficient plant, Broward County North Regional
WWTP. However, because each plant is treating varying degrees of nitrogen loading in addition to
carbonaceous loading, and has varying depths of diffuser submergence and alpha factors, a more
appropriate efficiency comparison is provided as power per total load treated as measured by the standard
oxygen requirement (SOR). On this basis, the Broward County North Regional WWTP and Boca Raton
WWTP are closer in efficiency, whereas the Plantation Regional WWTP utilizes 100% more energy than
the most efficient plant. The following section explores the reasons that the Plantation Regional WWTP,
and to a much lesser extent, the Boca Raton WWTP, are less efficient than the Broward County North
Regional WWTP.
The average energy use of the mechanical aerators at each facility are provided in Table 6.7. It is
apparent from Table 6.7 that the Broward County North Regional WWTP aerators indeed use less power
than the Boca Raton WWTP or Plantation Regional WWTP.
Table 6.7 – Average Mechanical Aerator Energy Use Comparison
(Nameplate hp)
Boca Raton
(hp used)
N Broward (hp used)
Plantation (hp used)
56 - - 59
100 92 69 100
125 - - 123
Avg Operating hp / Nameplate hp 92% 69% 98%
Factor 1.34 1.00 1.43
The mechanical aerator average power usage is broken down on a zone by zone basis in Table 6.8.
Table 6.8 demonstrates that Broward County North Regional WWTP and Plantation Regional WWTP both
taper their power usage down from Zone 1 to Zones 2 and 3, whereas Boca Raton WWTP does not.
Tapering aeration, from more aeration in the first zone to less in the later zones, is a common practice that
is used to provide more aeration where it is required in the first zone where most of the oxygen demand is
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incurred. Table 6.8 also demonstrates that on a power per tank volume basis, the Boca Raton WWTP
provides 26% more power and the Plantation Regional WWTP provides 82% more power than the most
efficient plant. The relative energy efficiency of the Broward County North Regional WWTP on the power
per aeration tank volume measure is related to their tapering down of power supplied in Zones 2 and 3.
However, it is important to note that Broward County North Regional WWTP is operating below the
recommended power input range for providing complete mixing of 0.75 – 1.5 hp per 1,000 cf
(Tchobanoglous et al., 2003) in zones 2 and 3. It is not known whether or not Broward County North
Regional WWTP currently experiences settling issues in their basins related to this factor.
Table 6.8 – Average Power Supplied Per Zone
Boca Raton N Broward Plantation
Zone 1 Avg Power (hp) 96.3 84.2 123.0
Zone 2 Avg Power (hp) 87.3 59.9 85.6
Zone 3 Avg Power (hp) 91.8 61.5 68.4
Zone 1 power / volume (hp / 1,000 cf) 1.03 0.97 2.43
Zone 2 power / volume (hp / 1,000 cf) 0.93 0.69 1.69
Zone 3 power / volume (hp / 1,000 cf) 0.98 0.71 1.35
Total power / volume (hp / 1,000 cf) 0.99 0.79 1.82
Factor 1.26 1.00 1.82
Typical power / volume requirement for adequate mixing (hp / 1,000 cf) 0.75 - 1.5
To further compare efficiencies, the current oxygen supplied by the mechanical aerators is
estimated based on horsepower, and the estimated oxygen required based on the methodology presented
earlier in this paper are compared in Table 6.9. From Table 6.9, it is apparent that Plantation Regional
WWTP is providing more than double the amount of oxygen required to meet their current treatment,
whereas Boca Raton WWTP and Broward County North Regional WWTP are currently supplying much
less excess oxygen.
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Table 6.9 – Current Oxygen Supplied vs. Oxygen Required
Boca Raton Broward Plantation
Adjusted oxygen transfer capacity (lb 02 / hr) (based on 3.0 lb / hp.hr and per Metcalf & Eddy, 2003 eq. 5-62)
2.3 2.1 2.0
Current average power supplied (hp) 558 1,481 831
Current estimated avg oxygen supplied (lb 02 / day) 30,600 75,700 39,500
Current estimated avg oxygen required (lb 02 / day) 22,600 64,300 16,900
% lb supplied vs required 135% 118% 234%
Factor 1.15 1.00 1.99
Potential Operational Modifications Based on Existing Energy Usage Comparison
The Plantation Regional WWTP aeration process energy intensity is significantly greater than the
City of Boca Raton WWTP and Broward County North Regional WWTP. The comparison in the previous
section indicates that the Plantation Regional WWTP is supplying power in excess of that required to meet
their oxygen demand.
It is apparent that the difference in energy intensity is due to a combination of three main factors:
1) Complete Nitrification / Extended SRT - Unlike the other two plants, the Plantation Regional
WWTP completely nitrifies, meaning that they typically supply more oxygen to the activated
sludge process compared to the other plants to completely oxidize ammonia to nitrite or nitrate.
The additional air supplied results in additional energy use. Although Plantation Regional WWTP
is not required to fully nitrify per the FDEP operation permit, the complete nitrification that occurs
is a byproduct of their extended SRT operating condition of over 30 days which they maintain to
reduce their solids loading to their digesters.
2) Higher DO Level - Plantation Regional maintains a DO of 1.5 mg/L compared to 1.0 mg/L at
Broward County North Regional WWTP and 0.5 mg/L at the City of Boca Raton WWTP. The
increased DO that the Plantation Regional WWTP is able to maintain is likely due to the reduced
oxygen demand in the system related to a high SRT and resulting low food to mass (F/M) ratio.
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3) Inefficient Equipment - Thirdly, cursory measurements obtained of the amp draws from Plantation
Regional WWTP’s mechanical aerators indicate that their energy consumption per aerators is
greater than the City of Boca Raton and Broward County North Regional WWTPs. It is not clear
whether the additional measured amp draws are due to greater submergence of the aerators (which
helps maintain the apparent higher DO levels), or motor or mechanical inefficiency due to aged or
obsolete motors or mechanical components.
The payback for the Plantation Regional WWTP is calculated based on the existing base condition
of inefficient operation related to the three factors discussed above. For the purposes of comparison, a
hypothetical side case is calculated by assuming that the Plantation Regional WWTP could operate with
one basin normally out of service. SRT could be maintained at greater than 20 days with the same mixed
liquor concentration by reducing the aerated volume by one-third, which would sustain complete
nitrification and result in a relatively small percent increase in sludge production. Therefore, the costs
related to processing and hauling the additional sludge downstream would also be expected to be minimal.
Operating with one basin out of service and assuming the same proportional power usage (two
thirds) results in the following scenario. Table 6.10 demonstrates that with one basin out of service, the
power per total load treated is still greater than the most efficient Broward County North Regional WWTP
and the power per volume is equivalent to the Broward County North Regional WWTP. Table 6.11
demonstrates that the oxygen supplied under the operational modification still exceeds the amount required
by 56%.
Table 6.10 – Plantation Operational Modification - Energy Intensity Comparison
Parameter Value
Power per carbonaceous load treated (kWh / lb CBOD5) 1.22
Factor (compared to N. Broward) 2.44
Power per total load treated (kWh / lb SOR) 0.22
Factor (compared to N. Broward) 1.33
Power per volume treated (kWh / MG) 637
Factor (Compared to N. Broward) 1.00
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Table 6.11 – Plantation Operational Modification - Current Oxygen Supplied vs. Oxygen Required
Parameter Value
Adjusted oxygen transfer capacity (lb 02 / hr) (per eq. 5-62) 2.0
Projected average power supplied (hp) 554.1
Projected avg oxygen supplied (lb 02 / day) 26,330
Projected avg oxygen required (lb 02 / day) 16,886
% lb supplied vs required 156%
Table 6.12 and Table 6.13 present the results of implementing the ECMs following making the
operational modification of taking one basin out of service at the Plantation Regional WWTP. It is
apparent from the results that even if Plantation were to make the suggested operational modification or
taking one basin out of service, the payback for implementing the ECMs is still excellent at a median
estimate of 17 years were they to maintain a fully nitrifying plant. If the Plantation Regional WWTP were
to only partially nitrify, even greater energy savings and payback would result. It is important to note that
the decision to reduce SRT and partially nitrify would need to be balanced with the consideration of the
additional sludge that would be produced and how much could be reliably digested in the anaerobic
digesters to prevent a great increase in final sludge requiring disposal. Because taking one basin offline
would still maintain an SRT of greater than 20 days, a significant increase in sludge production should not
be anticipated.
Table 6.12 – Plantation Operational Modification –Energy Savings Resulting From ECM Implementation Following Operational Modification
Technology Level of Treatment Avg. Operating
hp
kWh / Day
% Eff. Gain
Ann. Energy Cost Savings ($)
Base Case Complete Nitrification 554 9,920 - -
ECM No. 1 - 3 Complete Nitrification 251 4,493 55% $138,667
ECM No. 1 - 3 Partial Nitrification 176 3,150 68% $172,980
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Table 6.13 – Plantation Operational Modification – Payback Resulting From ECM Implementation Following Operational Modification
Technology Level of Treatment
% Eff.
Gain
Avg. Daily
Energy Savings (kWh)
Ann. Energy
Cost Savings
($)
Payback (Low Est)
(Years)
Payback (Median
Est) (Years)
Payback (High Est)
(Years)
ECM No. 1 - 3 Complete Nitrification 55% 5427 $138,667 11 17 27
ECM No. 1 - 3 Partial Nitrification 68% 6770 $172,980 9 13 20
6.7 Ocean Outfall Rule Compliance
In addition to providing energy savings and increased treatment capacity, installation of the
proposed ECMs at the Boca Raton WWTP and the Broward County North Regional WWTP provide
additional capacity to comply with the ‘Ocean Outfall’ rule, (the Plantation Regional WWTP does not
discharge to an ocean outfall thus the Ocean Outfall rule is not applicable). The use of ocean outfalls for
wastewater effluent disposal were mandated in consolidated bill Chapter 2008-232 and was signed into law
on July 1, 2008, known as the ‘Outfall Rule’, which mandates that the discharge of domestic wastewater
through ocean outfalls meet advanced wastewater treatment (AWT) and management requirements by
December 31, 2018 and that outfall use cease except for emergency usage by December 31, 2025. The rule
also requires that utilities distribute at least 60% of the effluent waste stream that was previously being
discharged to the ocean as reclaimed water. AWT standards as defined by Florida Statute 403.086(4) are
limited to the following concentrations (Hazen and Sawyer, 2010):
• Biochemical Oxygen Demand (CBOD5) = 5 mg/L
• Total Suspended Solids (TSS) = 5 mg/L
• Total Nitrogen (TN) = 3 mg/L
• Total Phosphorus (TP) = 1 mg/L
• High level disinfection (HLD) of the effluent per Florida Administrative Code 62-600.440(5)
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To meet these requirements, plants in southeast Florida utilizing ocean outfalls are generally faced
with the following options:
• Option 1: Continue the current treatment process and construct facilities to meet AWT standards
by 2018
• Option 2: Reduce cumulative outfall loadings of TN and TP occurring between December 31,
2008 and December 31, 2025, as equivalent to that which would be achieved if the AWT
requirements were fully implemented beginning December 31, 2018, and continued through
December 31, 2025; or
• Option 3: Continue the current treatment process and construct a 100% reuse system by 2018.
Option 1 has been investigated at southeast Florida WWTPs, and it has generally been concluded
that it is not cost feasible. As such, utilities are exploring Option 2 and Option 3 as more cost beneficial
options. To delay the conversion to 100% reuse, Broward County North Regional WWTP concluded that
they could operate their aeration basins in partial nutrient removal mode, in which they fully nitrify their
wastestream from ammonia to nitrate, and partially denitrify to nitrogen gas utilizing an anoxic zone in the
first zone of their aeration basins. The anoxic zone could be outfitted with fine bubble diffusers that could
normally remain off to maintain anoxic conditions, but could periodically be “bumped” To maintain mixing
and prevent solids form depositing. Operation in partial nutrient removal mode would allow Broward
County North Regional WWTP to reduce their cumulative loading to the outfall from current to 2025 as
equivalent to that which would be achieved if the AWT requirements were fully implemented by 2018
(Hazen and Sawyer, 2010).
At the City of Boca Raton, the Outfall Rule could not be satisfied solely by switching to partial
nutrient removal. Loading would also have to be reduced by increasing reclaimed water distribution
capacity. The City of Boca Raton’s strategy for meeting the Ocean Outfall rule is shifting to 100% reuse
by 2018. However, reducing their current loading TN and TP loading to the ocean outfall would provide
additional time and flexibility for the City of Boca Raton WWTP to comply with the Outfall Rule. The
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current mechanical aeration processes at Boca Raton WWTP and North Broward WWTP cannot provide
adequate oxygen to operate in partial nutrient removal mode.
6.8 Greenhouse Gas Emissions
Table 6.14 presents the amount of total annual electricity saved for the three facilities studied. The
table also shows various greenhouse gas reduction measures that municipalities may employ, and shows the
equivalent units for each method that result in an equal amount of annual greenhouse gas emissions
reduction.
Table 6.14 – Greenhouse Gas Prevention Equivalency For Three Facilities Studied
Total
Total Electricity saved (MWh/Year) 10,013
Saving this amount of electricity annually is equivalent to preventing or sequestering CO2 gas by the following methods:
Total
Release of Metric Tons of CO2 (per year) 6,904
Converting From Full-Size Pick Up Trucks to Toyota Prius Hybrids (# of vehicles) a, c 1,548
Sequestering Carbon By Planting Tree Seedlings Grown For 10 Years (# of seedlings) d 177,030
Amount of pine forest acreage that sequesters an equivalent amount of CO2 (# of acres) d 1,472
Converting traffic signals from incandescent to LED bulbs (# of signals) b 13,716
a Assumes average mileage per gallon being increased from 16 mpg to 46 mpg at 15,000 miles per driven annually. (Peters 2008)
b Assumes signals are reduced from an average of 100W to 20W, for a savings of 730 kWh/year (Peters 2008)
c Calculations based on 8.92*10-3 metric tons CO2/gallon of gasoline and 6.8956 x 10-4 metric tons CO2 / kWh (US EPA 2011)
d Calculated using EPA’s Greenhouse Gas Equivalency calculator (US EPA 2011)
Reduction of greenhouse gases is a tangible benefit that will help the utilities in the study meet
regional goals for greenhouse gas reduction and energy efficiency. For example, the Broward County
Climate Change Action Plan states as a specific goal to reduce their utility carbon footprint (Broward
County, 2010), which could help be achieved with the implementation of ECMs at the Broward County
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North Regional WWTP and Plantation Regional WWTP. The Palm Beach County – Green Task Force On
Environmental Sustainability and Conservation recommended that a comprehensive county wide energy
conservation and greenhouse gas reduction strategy be implemented (Palm Beach County, 2009), which
could help be achieved through implementation of ECMs at the City of Boca Raton WWTP. On a
statewide level, the Governor’s Climate Action Plan, Executive Order # 07-128, mandates reduction of
statewide Greenhouse Gas Emissions by the year 2017 to the year 2000 levels (Palm Beach County, 2009).
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VII. CONCLUSIONS AND RECOMMENDATIONS
7.1 Conclusions
A model was developed to estimate the energy savings and resulting cost savings that can be
realized by implementing ECMs at three conventional activated sludge WWTPs in southeast Florida. The
ECMs investigated are 1) Fine Bubble Diffusers; 2) Single-Stage Turbo Blowers; and 3) Automatic
Dissolved Oxygen (DO) Control. The results of the analysis are provided as Tables 7.1 through 7.4:
Table 7.1 – Life Cycle Cost Analysis Assumptions
$/ kWh Bond Rate CPI
Inflation
Real Rate
(interest) Energy
Inflation
Planning Period (years)
0.07 4.7% 2.5% 2.2% 0.08% 20
Table 7.2 – Life Cycle Cost Analyses Estimated Costs
Plant Level of
Treatment
Annual Delta O&M
Foregone Capital
Replacement Net Present
Value Capital
Cost
NPV of Capital, O&M,
Foregone Capital
Boca Raton Partial Nitrification -$10,091 -$1,558,926 $3,261,794 $1,541,011
N Broward Partial Nitrification -$12,127 -$3,035,109 $7,954,846 $4,725,218
Plantation Complete Nitrification
-$9,133 -$1,034,902 $3,099,083 $1,917,692
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Table 7.3 – Life Cycle Cost Analyses Estimated Savings
Plant Level of
Treatment hp
Reduction % Eff. Gain
Ann. Energy
Cost Savings
Energy Savings Net
Present Value
Boca Raton Partial Nitrification 209 37% $95,404 ($1,541,495)
N Broward Partial Nitrification 743 50% $340,074 ($5,494,781)
Plantation Complete Nitrification 580 70% $265,398 ($4,288,205)
Table 7.4 – Life Cycle Cost Analyses Estimated Median Paybacks
Boca Raton N Broward Plantation
Level of Treatment Partial Nitrification Partial Nitrification Complete Nitrification
Payback (years) 20 17 8
AACE Class 4 Cost Estimate Range
(years) 11 - 37 11 - 28 6 - 13
Paybacks – A median payback estimate of 20 years or under is predicted at all three plants studied,
which meets the 20 year threshold typically considered by most plant managers to be a compelling level of
payback. The predicted levels of payback of 20 years or less for all plants are compelling arguments for
plants to implement ECM Nos. 1 through 3. When accounting for the cost estimating accuracy range for
AACE Class 4 estimates of -20 to + 30 percent, the paybacks for the three plants can rise to 13 to 37 years.
Regional Electricity Savings - Approximately 1.14 MWs can be saved, or approximately 10,000
MWh can be saved per year if the ECMs were implemented at all three plants. At the current price of
$0.07 per kWh, 10,000 MWh translates to $701K per year.
Greenhouse Gas Prevention - Saving this amount of energy is equivalent to preventing 6,900
metric tons per year of greenhouse gas release by converting approximately 13,700 traffic signals from
incandescent to LED bulbs, a commonly employed tactic by municipalities. The amount of greenhouse gas
emissions is also equivalent to converting 1,548 fleet vehicles from full-size pick up trucks to Toyota
148
Priuses, or by planting 177,000 tree seedlings every year (assuming amount of carbon sequestered in 10
years of growth).
Model Accuracy Verification – The model’s accuracy was verified by comparing actual side-by-
side data available from the Broward County North Regional WWTP for fine bubble diffused aeration and
mechanical aeration energy usage. Broward County North Regional WWTP provides a remarkably unique
opportunity to measure the model’s accuracy due to the side by side arrangement of mechanical aeration
versus fine bubble diffused aeration in identical basins with identical influent wastewater characteristics.
The verification results indicated that the model is reasonably accurate at predicting average airflow rates
and energy use.
The Greatest Cumulative Benefit Is Achieved When All 3 ECMs are Implemented - The benefit of
implementing each technology is quantified on an individual and cumulative basis, to identify which
technologies are cost-beneficial and which are not. It is apparent that the ECM No. 1 – Fine Bubble
Diffusers has the greatest (least beneficial) incremental payback in general, generally over 20 years when
not considering addition of ECM No. 2 and No. 3. What these results clearly demonstrate is that to achieve
excellent paybacks at the three plants studied, implementation of fine bubble diffusers is not enough.
Installation of high efficiency blowers and DO control systems are needed. This finding should be
instructive for utilities considering implementation of fine bubble diffusers but possibly not high efficiency
blowers or DO control due to capital constraints. Installation of high efficiency blowers (ECM No. 2) and
automatic DO control (ECM No. 3) leverages the benefit of fine bubble diffusers (ECM No. 1) and will
likely result in a payback below 20 years. The results demonstrate that each successive ECM accumulates
for a cumulative total improvement in efficiency, resulting in an average predicted energy savings of 52
percent at the three plants studied. Figure 7.1 demonstrates the average contribution of each ECM to the
total overall efficiency improvement.
149
Fine Bubble Diffusers, 23%
Turbo Blowers, 12%
DO Control, 18%
Remaining Energy Use, 48%
Figure 7.1 – Average Contribution of Each ECM to Overall Total Energy Savings
Sensitivity Analysis - Paybacks can be degraded or improved by varying sensitive model
parameters. Payback predictions are improved by considering the effects of public or private grants on
capital cost such as the $1.2 million grant recently received by the Palm Beach County SRWRF for
installation of a biogas generator, resulting in a project capital cost reduction of 33%. Payback can also be
improved from a rise in the cost of electricity, increase in assumed predicted blower efficiency, or other
factors. Conversely, payback predictions are degraded by considering a lower assumed cost of electricity,
blower efficiency, or other factors. However, the paybacks predicted by the model are relatively resilient to
variations in the key variable inputs discussed above. Changes in capital cost due to third-party grants or
cost estimating errors, or sudden changes in electricity costs are the most sensitive parameters effecting
payback. A recent precipitous drop in southeast Florida plant’s electrical bills from 2009 to 2010 of
approximately 20 percent recently occurred, due to a reduction in “pass through fuel charge” from FPL.
Were fuel charges to rise again on a similar scale, paybacks would be improved for each plant from 2 to 5
years.
Variable Treatment Efficiencies Prior to ECM Implementation - The results demonstrate that prior
to implementing ECM’s, the Boca Raton WWTP and Broward County North Regional WWTP
150
demonstrate similar scales of efficiency on a kWh / lb of CBOD5 and kWh / SOR basis with Broward
County North Regional WWTP being the most efficient. However, Plantation Regional WWTP shows a
scale of efficiency almost three times less efficient than the other two plants. The main reason Plantation
Regional WWTP is the least efficient prior to ECM implementation is that it operates as an extended
aeration facility by maintaining a long SRT above 30 days, to minimize sludge yield and reduce their
digester solids loading.
The apparent discrepancy in current energy intensity between Plantation WWTP and the other two
facilities is the main reason for the excellent payback of 8 years predicted relative to the other plants due to
the increased opportunity for realizing energy savings. Therefore, the effects of making zero-capital cost
operational improvements first to improve the efficiency before implementing ECMs was explored. It is
apparent that even if Plantation were to improve their efficiency by reducing SRT through taking one of the
three aeration basins offline, the payback for implementing the ECMs is still excellent at a median estimate
of 17 years.
Conversely, the Broward County North Regional WWTP current operation is currently the most
efficient. As a consequence, the payback would be the least beneficial at a median value of 32 years if not
considering the effects of removing Module D from service. However, the mechanical aerators that are no
longer required to be operated at Module D are a key source of energy savings for this analysis, resulting in
an excellent payback for implementing EMC Nos. 1 through 3 of 17 years.
Correlated Unit Efficiencies and Capital Costs Following ECM Implementation - Following
theoretical implementation of the ECM’s, each activated sludge treatment process demonstrates relatively
correlated scales of predicted efficiency on a kWh / SOR basis with average value of 0.10 kWh / SOR
treated for the Current Treatment, Partial Nitrification, and Complete Nitrification scenarios. The predicted
capital costs for implementing the proposed ECMs are well correlated on a Capital Cost / MGD ADF
Capacity treated basis with an average value of $205K / MGD ADF Capacity treated over the design
period. Although the dataset of three plants is too limited to predict universal correlation, it appears that
other mechanically aerated plants implementing the ECMs suggested in this study may roughly predict
their achievable energy savings based on the 0.10 kWh / SOR benchmark and their rough capital cost based
on the $205K / MGD ADF Capacity benchmark. The kWh / SOR treated and capital cost / MGD ADF
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benchmark values can be supplemented with plant specific O&M and foregone repair and replacement
costs to estimate a given plant’s payback in accordance with the methodology of this study. An equation
was developed and is provided herein, which is a formula for completing a rough payback analysis for
other mechanically aerated plants implementing ECM Nos. 1 through 3.
Critical Assumptions Were Researched - An average value of 72 percent efficiency was
determined to estimate average turbo blower performance and 62 percent to estimate multi-stage
centrifugal blower performance based on available surveys (Rohrbacher et al., 2010). An average value of
3.0 mg/L was determined to estimate average fine-bubble aeration DO levels without DO control, and 1.5
mg/L was determined to estimate practical fine-bubble aeration DO levels following implementation of DO
control based on numerous studies surveyed. It was determined that a feasibility study-level AACE Class
4 capital cost estimate was practical for this level of study, which implies a -20 / +30 percent accuracy
range in capital cost. Operation and maintenance (O&M) costs associated with implementing each
technology were researched based on similar studies and interviews with plant personnel. The critical
assumptions researched in this paper should inform other researchers conducting similar analyses
elsewhere.
7.2 Recommendations
Further Model Accuracy Verification
Although the model predictions appear to correlate reasonably well to the limited data available
from the Broward County North Regional WWTP for fine bubble diffused aeration energy usage and side
by side measured efficiency of mechanical aeration versus fine bubble diffused aeration, it is recommended
that additional data sets and verification of key assumptions be completed and used to verify the model.
The Broward County North Regional WWTP is currently under preliminary study by a third party for
potentially implementing ECMs similar to those proposed in this study at aeration basin Module A and
Module B. If implemented, the results of the implementation can be used to further gauge the accuracy of
the model predictions developed in this thesis.
Specific Wastewater Characterization
More accurate model results could be achieved through completing wastewater characterization
sampling events at each facility. Typical values were assumed for important variables for modeling
152
purposes, such as the nonbiodegradable volatile suspended solids or readily biodegradable chemical oxygen
demand (Dold, 2007; Melcer et al., 2003). More accurate characterization of these wastewater fractions at
each facility through conducting sampling events would allow for more accurate predictions of oxygen
demand and energy use through the methodology outlined in this thesis. In addition, removal of TSS and
BOD by primary clarifiers at the City of Boca Raton were conservatively estimated based on typical values
due to lack of historical primary clarifier effluent data. Specific characterization of the settleability of the
influent wastewater and removal capacity of the clarifiers at the City of Boca Raton through sampling
events would allow for more accurate prediction of influent wastewater, which could effect oxygen demand
and energy use predictions.
Biogas Optimization and Cogeneration
Another ECM at WWTPs that is an excellent candidate for completing regional life cycle cost
analyses is biogas optimization and cogeneration. Innovative power generation technologies, primary
sludge capture, and waste activated sludge pretreatment are technologies and methods that should be
included in a biogas optimization study. Locally, a biogas generator at the Palm Beach County –SRWRF
facility is currently under construction, which uses methane produced from the anaerobic digestion process
to power a generator to produce electricity, as opposed to wasting the methane to a waste gas flare. The
biogas generator is anticipated to reduce the facility’s energy draw by 14%. Many other plants could also
realize a benefit from biogas generation, including the Boca Raton WWTP, Broward County North
Regional WWTP, and the Plantation Regional WWTP.
Grants, Incentives, and Funding Sources
Payback can be improved through obtaining grants, incentives, or reduced interest loans.
Available public and private funding at the local, state, and federal level should be investigated for each
facility as a potential way to improve the payback for ECMs. As a local example of success, the Palm
Beach County – SRWRF recently received a $1.2 million grant in 2009 from the US Department of Energy
toward the construction of a biogas generator, which reduced the capital cost of total project delivery by
33%. Alternative project delivery from Energy Services Performance Contractors (ESCOs) can also be
explored to finance projects, in which the ESCO finances the project with no or little capital upfront from
the owner and guarantees the energy savings, and the debt is paid back by the owner with money generated
153
by the energy savings over a certain time frame (Dobyns and Lequio, 2008). At the time of this
publication, the Broward County North Regional WWTP is currently under discussions with Chevron
Energy Solutions, an ESCO, to install a biogas generator, as well as ECMs similar to those discussed in this
study.
APPENDIX A-1 –BOCA RATON WWTP PRELIMINARY DESIGN DRAWINGS
154
155
156
157
158
159
APPENDIX A-2 –BOCA RATON WWTP DATA SPREADSHEETS
160
CITY OF BOCA RATON - ENERGY EFFICIENCY ANALYSIS SPREADSHEETSSPREADSHEET TABLE OF CONTENTS
1.1 INFLUENT EFFLUENT SPECIFIER1.2 FLOW PROJECTION2.0 AERATION CALCULATIONS - GLOBAL PARAMETERS2.1 AERATION CALCULATIONS - DIFFUSERS2.2 AERATION CALCULATIONS - TURBO BLOWERS2.3 AERATION CALCULATIONS - 1.5 MG/L DO CONTROL3.1.1 SYSTEM DESIGN - SIZE PIPES - TRAIN 13.1.2 SYSTEM DESIGN - SIZE PIPES - TRAINS 2 AND 33.2 SYSTEM DESIGN - ESTIMATE LOSSES THROUGH PIPES3.3 SYSTEM DESIGN - SYSTEM CURVE3.4 SYSTEM DESIGN - BLOWER DESIGN4.0 - COST ESTIMATE - SUMMARY4.1 - COST ESTIMATE - DEMOLITION4.2 - COST ESTIMATE - BLOWERS4.3 - COST ESTIMATE - DIFFUSERS4.4 - COST ESTIMATE - STRUCTURAL4.5 - COST ESTIMATE - MECHANICAL PIPING4.6 - COST ESTIMATE - INSTRUMENTATION4.7 - COST ESTIMATE - ELECTRICAL5.0 - O&M COSTS5.1 - O&M COSTS - REPLACE AERATORS6.0�LIFE�CYCLE�COST�ANALYSIS�INPUTS6.1.1 LIFE-CYCLE COST ANALYSIS6.1.2 LIFE-CYCLE COST ANALYSIS (LOW RANGE)6.1.3 LIFE-CYCLE COST ANALYSIS (HIGH RANGE)6.2 LIFE-CYCLE COST ANALYSIS SUMMARY
161
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8413
7022
7741
90.
53.
9A
DF
13.9
815
870
9592
333
1065
941
5311
04M
MA
DF
15.7
320
223
1226
749
614
054
4956
1554
Max
Day
21.0
228
204
3507
096
817
200
6596
1972
2007
- 20
09 3
Yea
r Ave
rage
- A
djus
ted
to 2
011-
2031
AD
FPR
IMA
RY
INF
FLO
WEF
F C
BO
DIN
F TS
SEF
F C
BO
DEF
F W
AS
V SIN
F TK
NEF
F N
H3
MG
DLB
SLB
SLB
S.LB
SLB
SLB
S.M
in D
ay10
.12
6695
4350
8714
2623
6943
6A
DF
14.5
516
516
9983
347
1109
343
2211
49M
MA
DF
16.3
721
046
1276
651
614
626
5158
1618
Max
Day
21.8
729
351
3649
710
0817
900
6865
2053
2007
- 20
09 -
Adj
uste
d to
Des
ign
Flow
of 1
7.5
MG
DPR
IMA
RY
INF
FLO
WEF
F C
BO
DIN
F TS
SEF
F C
BO
DEF
F W
AS
V SIN
F TK
NEF
F N
H3
MG
DLB
SLB
SLB
S.LB
SLB
SLB
S.M
in D
ay12
.16
8051
5231
105
1715
2849
524
AD
F17
.50
1986
112
004
417
1333
951
9713
82M
MA
DF
19.6
925
308
1535
162
117
587
6202
1945
Max
Day
26.3
035
295
4388
812
1221
525
8255
2468
162
1.2 FLOW PROJECTIONThis spreadsheet summarizes the Flow Projection through the 20 year design horizo
2008 128107 14.282009 128517 13.882010 129472 13.792011 130082 14.132012 130520 14.182013 131017 14.242014 131378 14.272015 131892 14.332016 132425 14.392017 133017 14.452018 133435 14.502019 133854 14.542020 134483 14.612021 134902 14.662022 135320 14.702023 135739 14.752024 136157 14.792025 136609 14.842026 137034 14.89 2007-2009 ADF 13.98 MGD2027 137461 14.94 2031 ADF 15.12 MGD2028 137889 14.98 2011-2031 Avg Flow 14.55 MGD2029 138319 15.032030 138751 15.082031 139179 15.12
Projected Population to 2025 per SFWMD 2001 Consumptive Use PermExtrapolated 2026 population =2025 population + average 2021-2025 population growExtrapolated 2027 population = extrapolated 2026 population + average 2022-2026 projectProjected Flow Year Y = (Projected Population Year Y / Projected Population Year X) * Projected Flow Year
YearProjectedPopulation
ProjectedFlow
14.00
14.20
14.40
14.60
14.80
15.00
15.20
2010 2015 2020 2025 2030 2035
Flow
(MG
D)
Year
Flow Projection
163
2.0 AERATION CALCULATIONS - GLOBAL PARAMETERSSpreadsheet 2.1 - 2.3 calculates the amount of air and horsepower needed to treat various flowrates and loading rates throughout the plant. 2.0 Aeration Calculations - Global Paramters spreadsheet specifies the glbaal variables input to spreadsheets 2.1 - 2.3.
Area�under�Aeration�per�Basin�(ft2)�= 21675 Manual�DO�Control�O2�(mg/L) 3#�of�basins�online�=� 2 Auto�DO�Control�O2�(mg/L) 1.5Side�water�Depth�(ft)�=� 13 MSC�Blower�Efficiency 0.62Diffuser�Submergence�(ft)�=� 12 Turbo�Blower�Efficiency 0.72Equation�For�System�Curve 2.74E�09 *�x^2 Concentration�at�Max�Day�(mg/L) 0.5Number�of�Diffusers�per�Basin�=� 3500 Pre�ECM�Existing�DO�(mg/L) 0.5Site�Elevation�(ft�above�MSL)�=� 10Minimum�Mix�Requirements�(scfm/ft2) 0.12 Y�(per�Dold,�2007) 0.49Minimum�Flow�per�Diffuser�(scfm) 0.5 (for�nitrifying�assume�5�day�SRT)Maximum�Flow�per�Diffuser�(scfm) 3.0General�Temperature 25 Fup�(Dold,�2007) 0.08Beta�(unitless)=� 0.98 VSS/TSS�(Metcalf�&�Eddy,�2003) 0.85Patm�(psi)�=� 14.7Patm�(mid�depth,�ft�wc/2/2.31�psi,�psi)�=� 2.60Csth�(per�App�D�for�mech�aer,�mg/L)�= 8.24Cs20�(DO�@�20�deg�C,�1�atm,�mg/L)�=� 9.08CstH*�(mg/L)�= 9.70Dens�Air�(lb/cf)�=� 0.0750Mass�Fraction�O2�in�air�=� 0.2315Alpha�=� 0.43Alpha�for�complete�nitrification�=� 0.5Average�of�minimum�SOTE a
Figure 2.10 & Sanitaire
Temp. Tau
0 1.65 1.4
10 1.2415 1.1220 125 0.9130 0.8335 0.7740 0.71
Submergence = 20.00-ft
y = 4.08E-04x2 - 3.82E-02x + 1.60E+00R² = 9.98E-01
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30 35 40
Tau
(dim
ensi
onle
ss)
Temperature (C)
Tau vs. Temperature
Air Average Minimum Average Minimum Results from trendline in chartFlow SOTE SOTE SOTE SOTE
(SCFM/Unit (%) (%) (%/ft) (%/ft) Constants�for�the�following�formula:�ax4+bx3+cx2+dx+e
0.59 46.83 41.25 2.34 2.06 Avg SOTE 0.05140.88 42.50 37.98 2.13 1.90 Avg SOTE �0.46031.00 41.26 37.37 2.06 1.87 Avg SOTE 1.54051.18 39.89 36.95 1.99 1.85 Avg SOTE �2.34731.47 38.48 35.92 1.92 1.80 Avg SOTE 3.27791.75 38.33 35.90 1.92 1.80 Min SOTE 0.04672.06 37.52 35.39 1.88 1.77 Min SOTE �0.40152.35 37.21 35.35 1.86 1.77 Min SOTE 1.27242.50 37.07 35.20 1.85 1.76 Min SOTE �1.79842.65 36.87 35.18 1.84 1.76 Min SOTE 2.75262.94 36.69 35.01 1.83 1.753.00 36.66 35.00 1.83 1.75
Air Average Minimum Average MinimumFlow SOTE SOTE SOTE SOTE
(SCFM/Unit (%) (%) (%/ft) (%/ft)
0.59 40.58 35.74 2.34 2.060.88 36.83 32.91 2.13 1.901.00 35.75 32.38 2.06 1.871.18 34.56 32.02 1.99 1.851.47 33.34 31.12 1.92 1.801.75 33.21 31.11 1.92 1.802.06 32.51 30.67 1.88 1.772.35 32.24 30.63 1.86 1.772.50 32.12 30.57 1.85 1.762.65 31.95 30.48 1.84 1.762.94 31.79 30.34 1.83 1.753.00 31.77 30.33 1.83 1.75
Submergence = 17.33-ft
y�=�0.0514x4 � 0.4603x3 +�1.5405x2 � 2.3473x�+�3.2779R²�=�0.9987
y�=�0.0467x4 � 0.4015x3 +�1.2724x2 � 1.7984x�+�2.7526R²�=�0.9944
1.50
1.60
1.70
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50
SOTE�%�/�fo
ot�of�d
iffuser�sub
mergence
SCFM/Diffuser
SOTE�vs.�SCFM/diffuser�Sanitaire�� Silver�Series�II��9"�Membrane�Disc�Diffuser�
Average�SOTE
Min.�SOTE
Poly.�(Average�SOTE)
Poly.�(Min.�SOTE)
164
2.1
AER
ATI
ON
CA
LCU
LATI
ON
S - D
IFFU
SER
SS
prea
dshe
et 2
.1 -
2.3
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
1 A
erat
ion
Cal
cula
tions
- D
iffus
ers
spre
adsh
eet p
redi
cts
the
effic
ienc
y im
prov
emen
t by
upgr
adin
g to
fine
bub
ble
diffu
sers
with
no
othe
r EC
Is.
Ass
umes
mul
ti-st
age
cent
rifug
al b
low
ers
at 6
2% e
ffici
ency
.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
FC
ur T
reat
2.�In
puts
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2007���2009
MGD
14.55
14.55
14.55
9.72
12.16
17.50
17.50
19.69
19.69
26.30
26.30
13.98
Num
ber�of�Basins�Online
22
22
22
22
22
22
So�=�CBO
Dinf
16,516
16,516
16,516
6,433
8,051
19,861
19,861
25,308
25,308
35,295
35,295
(lb/day)
15,870
S�=�CB
ODeff
347
347
347
84105
417
417
621
621
1,212
1,212(lb
/day)
333
Eq.�8�15�(w
here�hilighted),�PxBio�=�
10,414
10,414
8,709
1,086
1,359
12,523
10,473
16,544
13,341
18,540
17,077
(lb/day)
10,007
TKN�=�
4,322
4,322
4,322
2,277
2,849
5,197
5,197
6,202
6,202
8,255
8,255(lb
/day)
4,153
NH3�eff�=
�1,149
1,149
61419
524
1,382
731,945
822,468
110(lb
/day)
1,104
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
0.5
33
33
33
33
0.5
0.5mg/L
0.5
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
25Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
0.43
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
aa
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,923
1,923
3,216
1,727
2,162
2,313
3,868
2,271
4,519
3,562
6,096(lb
/day)
1,848
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AOR�=
23,551
23,551
31,570
17,721
22,177
28,320
37,963
32,163
46,441
52,353
65,403
(lb/day)
22,630
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(T�20)](Alpha)(F)}
0.43
0.30
0.34
0.30
0.30
0.30
0.34
0.30
0.34
0.43
0.50
0.43
SOR�=�
54,857
79,559
91,717
59,864
74,916
95,670
110,290
108,650
134,922
121,945
131,015(lb
/day)
52,712
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
2,194
3,182
3,668
2,394
2,996
3,826
4,411
4,346
5,396
4,877
5,240
2,108
TotalN
umbe
rof
Diffusers=
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
Total�N
umbe
r�of�Diffusers�=�
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
2.01
2.34
1.47
1.88
2.45
2.86
2.82
3.41
3.15
3.34
1.33
Diffuser�Flow,�scfm/diffuser�=�
1.33
2.01
2.34
1.47
1.88
2.45
2.86
2.82
3.41
3.15
3.34
1.28
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
23.50%
22.62%
22.36%
23.20%
22.72%
22.28%
22.03%
22.05%
22.62%
22.12%
22.42%
23.50%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�*�Den
sAir�*�%02
�in�air)
9,338
14,070
16,405
10,320
13,191
17,178
20,020
19,710
23,862
22,053
23,368
8,973
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
345
544
652
385
505
689
835
819
1055
948
1025
hp331
Dynam
ic�Losses
0.24
0.54
0.74
0.29
0.48
0.81
1.10
1.06
1.56
1.33
1.50
psi
0.22
Wire�to�Air�Eff�=�
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
Unitle
ss0.62
e=100%
*((P1+14.7)/14.7)0.283�1)/�1
��(P2
+14.7)/14.7)0.283�1)/�2)/((P1+14.7)/14.7)�0
.283�1)/�2
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
165
2.2
AER
ATI
ON
CA
LCU
LATI
ON
S - T
UR
BO
BLO
WER
SS
prea
dshe
et 2
.1 -
2.3
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
2 A
erat
ion
Cal
cula
tions
-Tur
bo B
low
ers
spre
adsh
eet p
redi
cts
effic
ienc
y im
prov
emen
t of f
ine
bubb
le d
iffus
ers
with
turb
o bl
ower
s as
sum
ing
72%
effi
ency
.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
F
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�Inpu
tsMGD
14.55
14.55
14.55
9.72
12.16
17.50
17.50
19.69
19.69
26.30
26.30
Num
ber�of�Basins�Online
22
22
22
22
22
2So�=�CBO
Dinf
16,516
16,516
16,516
6,433
8,051
19,861
19,861
25,308
25,308
35,295
35,295
(lb/day)
S�=�CB
ODeff
347
347
347
84105
417
417
621
621
1,212
1,212(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
10,414
10,414
8,709
1,086
1,359
12,523
10,473
16,544
13,341
18,540
17,077
(lb/day)
TKN�=�
4,322
4,322
4,322
2,277
2,849
5,197
5,197
6,202
6,202
8,255
8,255(lb
/day)
NH3�eff�=
�1,149
1,149
61419
524
1,382
731,945
822,468
110(lb
/day)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
0.5
33
33
33
33
0.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,923
1,923
3,216
1,727
2,162
2,313
3,868
2,271
4,519
3,562
6,096(lb
/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AOR�=
23,551
23,551
31,570
17,721
22,177
28,320
37,963
32,163
46,441
52,353
65,403
(lb/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(T�20)](Alpha)(F)}
0.43
0.30
0.34
0.30
0.30
0.30
0.34
0.30
0.34
0.43
0.50
SOR�=�
54,857
79,559
91,717
59,864
74,916
95,670
110,290
108,650
134,922
121,945
131,015(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
2,194
3,182
3,668
2,394
2,996
3,826
4,411
4,346
5,396
4,877
5,240
TotalN
umbe
rof
Diffusers=
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
Total�N
umbe
r�of�Diffusers�=�
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
2.01
2.34
1.47
1.88
2.45
2.86
2.82
3.41
3.15
3.34
Diffuser�Flow,�scfm/diffuser�=�
1.33
2.01
2.34
1.47
1.88
2.45
2.86
2.82
3.41
3.15
3.34
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
23.50%
22.62%
22.36%
23.20%
22.72%
22.28%
22.03%
22.05%
22.62%
22.12%
22.42%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�*�Den
sAir�*�%02
�in�air)
9,338
14,070
16,405
10,320
13,191
17,178
20,020
19,710
23,862
22,053
23,368
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
297
468
561
331
435
594
719
705
908
816
883hp
Dynam
ic�Losses
0.24
0.54
0.74
0.29
0.48
0.81
1.10
1.06
1.56
1.33
1.50
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
166
2.3
AER
ATI
ON
CA
LCU
LATI
ON
S - 1
.5 M
G/L
DO
CO
NTR
OL
Spr
eads
heet
2.1
- 2.
3 ca
lcul
ates
the
amou
nt o
f air
and
hors
epow
er re
quire
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
3 A
erat
ion
Cal
cula
tions
-1.5
MG
/L D
o C
ontro
l spr
eads
heet
pre
dict
s ef
ficie
ncy
impr
ovem
ent o
f fin
e bu
bble
diff
user
s, tu
rbo
blow
ers,
and
DO
Con
trol
.
Cur
Tre
atA
DF
AD
F +
Nit
Min
Day
Min
Day
AD
F A
DF
MM
AD
FM
MA
DF
MD
FM
DF
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�Inpu
tsMGD
14.55
14.55
14.55
9.72
12.16
17.50
17.50
19.69
19.69
26.30
26.30
Num
ber�of�Basins�Online
22
22
22
22
22
2So�=�CBO
Dinf
16,516
16,516
16,516
6,433
8,051
19,861
19,861
25,308
25,308
35,295
35,295
(lb/day)
S�=�CB
ODeff
347
347
347
84105
417
417
621
621
1,212
1,212(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
10,414
10,414
8,709
1,086
1,359
12,523
10,473
16,544
13,341
18,540
17,077
(lb/day)
TKN�=�
4,322
4,322
4,322
2,277
2,849
5,197
5,197
6,202
6,202
8,255
8,255(lb
/day)
NH3�eff�=
�1,149
1,149
61419
524
1,382
731,945
822,468
110(lb
/day)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
0.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
0.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,923
1,923
3,216
1,727
2,162
2,313
3,868
2,271
4,519
3,562
6,096(lb
/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AOR�=
23,551
23,551
31,570
17,721
22,177
28,320
37,963
32,163
46,441
52,353
65,403
(lb/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(T�20)](Alpha)(F)}
0.43
0.38
0.44
0.38
0.38
0.38
0.44
0.38
0.44
0.43
0.50
SOR�=�
54,857
62,636
72,208
47,131
58,981
75,320
86,830
85,539
106,223
121,945
131,015(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
2,194
2,505
2,888
1,885
2,359
3,013
3,473
3,421
4,249
4,877
5,240
TotalN
umbe
rof
Diffusers=
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
7000
Total�N
umbe
r�of�Diffusers�=�
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
7,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
1.55
1.81
1.11
1.45
1.90
2.21
2.17
2.75
3.15
3.34
Diffuser�Flow,�scfm/diffuser�=�
1.33
1.55
1.81
1.11
1.45
1.90
2.21
2.17
2.75
3.15
3.34
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
23.50%
23.08%
22.78%
24.22%
23.25%
22.71%
22.47%
22.49%
22.08%
22.12%
22.42%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�*�Den
sAir�*�%02
�in�air)
9,338
10,856
12,679
7,783
10,148
13,268
15,459
15,211
19,245
22,053
23,368
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
297
350
416
245
325
438
523
513
684
816
883hp
Dynam
ic�Losses
0.24
0.32
0.44
0.17
0.28
0.48
0.65
0.63
1.01
1.33
1.50
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
5202
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
167
3.1.
1 SY
STEM
DES
IGN
- SI
ZE P
IPES
- TR
AIN
1Th
is s
prea
dshe
et d
emon
stra
tes
the
sizi
ng o
f the
pro
pose
d ae
ratio
n pr
oces
s ai
r pip
es a
t Tra
in 1
.Fr
om 5
th O
rder
Cur
ve F
it of
Ste
phen
son/
Nix
on,
RH
Inle
t =
0.41
Figu
re 4
-1 -
Sat
urat
ion
Wat
er V
apor
Pre
ssur
e,T d
isch
arge�=
175
FW
ater
vap
or p
ress
ure
(psi
) vs
tem
pera
ture
(°F)
can
P
disc
harg
e =
#VA
LUE
!ps
igbe
cal
cula
ted
with
the
follo
win
g fo
rmul
a:V
p ac
t6.
7169
0069
8V
P =
a*T
5+�b*
T4+�c*T3
+�d*
T2+�e*T�+�f
VP
std
0.33
9020
46W
here
:a
=2.
268E
-11
b =
-2.4
9E-1
0P
er T
able
5-2
8 - M
etca
lf &
Edd
yc
=5.
083E
-07
Typi
cal a
ir ve
loci
ties
in a
erat
ion
d =
7.41
6E-0
6he
ader
pip
ese
=0.
0014
849
Pipe
Dia
Velo
city
f =0.
0162
738
Infp
m1
- 312
00 -
1800
4 - 1
018
00 -
3000
12 -
2427
00 -
4000
30 -
6038
00 -
6500
Airf
low
sA
vera
ge A
nnua
l Air
Flow
, Ful
ly N
itrify
:20
,020
scfm
#VA
LUE
!ac
fmM
axim
um M
onth
Air
Flow
, Ful
ly N
itrify
:23
,862
scfm
#VA
LUE
!ac
fmM
axim
um D
ay A
ir Fl
ow, F
ully
Nitr
ify:
23,3
68sc
fm#V
ALU
E!
acfm
Tota
l Air
Flow
:#V
ALU
E!
scfm
#VA
LUE
!sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
36in
Act
ual V
eloc
ity:
#VA
LUE
!fp
m#V
ALU
E!
fpm
Pea
k D
ayM
ax. M
onth
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
Num
ber o
f Par
alle
l Aer
atio
n Tr
ains
:2
ea2
eaA
ir Fl
ow P
er T
reat
men
t Tra
in:
#VA
LUE
!sc
fm#V
ALU
E!
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:30
inA
ctua
l Vel
ocity
:#V
ALU
E!
fpm
#VA
LUE
!fp
m
Num
ber o
f Zon
es p
er tr
ain:
3ea
3ea
Air
Flow
To
Trai
n 2
and
3:#V
ALU
E!
scfm
#VA
LUE
!sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
24in
Act
ual V
eloc
ity:
#VA
LUE
!fp
m#V
ALU
E!
fpm
Air
Flow
To
Trai
n 3
:#V
ALU
E!
scfm
#VA
LUE
!sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
16in
Act
ual V
eloc
ity:
#VA
LUE
!fp
m#V
ALU
E!
fpm
Air
Flow
Spl
it:#V
ALU
E!
scfm
#VA
LUE
!sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
12in
Act
ual V
eloc
ity:
#VA
LUE
!fp
m#V
ALU
E!
fpm
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
168
3.1.
2 SY
STEM
DES
IGN
- SI
ZE P
IPES
- TR
AIN
S 2
AN
D 3
This
spr
eads
heet
dem
onst
rate
s th
e si
zing
of t
he p
ropo
sed
aera
tion
proc
ess
air p
ipes
at T
rain
2-3
.
RH
Inle
t =
0.41
From
5th
Ord
er C
urve
Fit
of S
teph
enso
n/N
ixon
, T d
isch
arge�=
175
°FFi
gure
4-1
- S
atur
atio
n W
ater
Vap
or P
ress
ure,
Pdi
scha
rge
=7.
14ps
igW
ater
vap
or p
ress
ure
(psi
) vs
tem
pera
ture
(°F)
can
V
p ac
t6.
7169
0069
8be
cal
cula
ted
with
the
follo
win
g fo
rmul
a:V
P s
td0.
3390
2046
VP
= a
*T5+�b*
T4 �+�c*T
3 �+�d*T
2+�e*T�+�f
Whe
re:
a =
2.26
8E-1
1P
er T
able
5-2
8 - M
etca
lf &
Edd
yb
=-2
.49E
-10
Typi
cal a
ir ve
loci
ties
in a
erat
ion
c =
5.08
3E-0
7he
ader
pip
esd
=7.
416E
-06
Pipe
Dia
Velo
city
e =
0.00
1484
9In
fpm
f =0.
0162
738
1 - 3
1200
- 18
004
- 10
1800
- 30
0012
- 24
2700
- 40
0030
- 60
3800
- 65
00
Airf
low
sA
vera
ge A
nnua
l Air
Flow
, Ful
ly N
itrify
:20
,020
scfm
18,3
89ac
fmM
axim
um M
onth
Air
Flow
, Ful
ly N
itrify
:23
,862
scfm
21,9
18ac
fmM
axim
um D
ay A
ir Fl
ow, F
ully
Nitr
ify:
23,3
68sc
fm21
,464
acfm
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
y,
yy
,,
Max
. Mon
thP
eak
Day
Air
Flow
To
Zone
s 1,
2, a
nd 3
for T
rain
s 1
and
2:21
,918
scfm
21,4
64sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
36in
Act
ual V
eloc
ity:
3,10
1fp
m3,
036
fpm
Air
Flow
To
Zone
s 2
and
3 fo
r Tra
ins
1 an
d 2:
14,6
12sc
fm14
,309
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:30
inA
ctua
l Vel
ocity
:2,
977
fpm
2,91
5fp
m
Air
Flow
To
Zone
s 3
for T
rain
s 1
and
2:7,
306
scfm
7,15
5sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
24in
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
169
3.2
SYST
EM D
ESIG
N -
ESTI
MA
TE L
OSS
ES T
HR
OU
GH
PIP
ESFr
om 5
th O
rder
Cur
ve F
it of
Ste
phen
son/
Nix
on,
This
spr
eads
heet
dem
onst
rate
s th
e ca
lcul
atio
n of
wor
st-c
ase
head
loss
thro
ugh
the
prop
osed
aer
atio
n pi
ping
sys
tem
.Fi
gure
4-1
- S
atur
atio
n W
ater
Vap
or P
ress
ure,
Wat
er v
apor
pre
ssur
e (p
si) v
s te
mpe
ratu
re (°
F) c
an
P in
let =
14
.53
psia
be c
alcu
late
d w
ith th
e fo
llow
ing
form
ula:
T in
let =
10
1°F
Qpr
oces
s23
368
scfm
VP
= a
*T5+�b*
T4+�c*T3
+�d*
T2+�e*T�+�f
#VA
LUE
!0.
41Q
proc
ess
2561
0.51
icfm
Whe
re:
T dis
char
ge�=
175
°FQ
proc
ess
2151
0.33
acfm
a =
2.27
E-1
1P
disc
harg
e =
7.1
psig
b =
-2.5
E-1
0��=
0.00
0225
ft2/s
c =
5.08
E-0
7�
=0.
0000
5in
ches
for s
t. st
eel
d =
7.42
E-0
6�
act=
0.09
2404
2lb
/scf
e =
0.00
1485
Vp
act
6.71
6900
7f =
0.01
6274
VP
std
0.33
9020
5V
p in
let
0.97
8097
1
Des
crip
tion
Cum
mul
ativ
e Lo
ssh L
(inH
2O)
h L(p
si)
(1)
Inle
t Filt
er L
oss
30.
1082
3(2
)In
let S
ilenc
er L
oss
1.5
0.05
411
(3)
Loss
acr
oss
diffu
ser
120.
4329
Tota
l Blo
wer
Pip
ing
Inle
t Los
ses
=0.
16ps
i
Min
or L
osse
s (e
st.)
Cum
mul
ativ
e Lo
ssD
escr
iptio
nD
iam
(in)
Q (s
cfm
)Q
(icf
m)
Q (a
cfm
)D
iam
(in )
Vel (
fpm
)Le
ngth
(ft)
Re
�/D
f cal
chi
(inH
2O)
h L(in
H2O
)�
Kh L
(inH
2O)
h L(p
si)
h L(in
H2O
)h L
(psi
)
(1)
16" B
low
er O
utle
t16
5841
.93
6402
.628
5377
.58
1638
51.4
113
4.95
E+0
60.
0000
030.
009
1.14
1064
0.10
2743
5.2
5.93
353
0.21
4052
5.93
353
0.21
4052
(2)
30" A
ir P
ipin
g36
2336
7.7
2561
0.51
2151
0.3
3630
43.0
8977
5.21
E+0
70.
0000
010.
007
0.71
236
0.12
7462
3.3
2.35
0789
0.08
4805
8.28
432
0.29
8857
(3)
24" A
ir P
ipin
g30
1168
3.9
1280
5.26
1075
5.2
3021
91.0
2412
95.
23E
+07
0.00
0002
0.00
70.
3692
880.
1341
552.
650.
9786
120.
0353
039.
2629
320.
3341
61(4
)20
" Air
Pip
ing
2485
36.8
485
36.8
3778
58.2
924
2501
.371
843.
11E
+07
0.00
0002
0.00
70.
4813
120.
1504
220.
850.
4091
150.
0147
599.
6720
470.
3489
19(5
)14
" Air
Pip
ing
1638
94.6
242
68.4
1835
85.0
616
2567
.607
125
3.17
E+0
70.
0000
030.
008
0.50
7139
0.36
2048
2.27
1.15
1206
0.04
153
10.8
2325
0.39
0449
(6)
12" A
ir P
ipin
g/D
iff. H
ead
1219
47.3
121
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0917
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312
2282
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79E
+06
0.00
0004
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90.
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1812
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81.
9233
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0693
8612
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630.
4598
35(7
)6"
Air
Pip
ing
616
2.27
617
7.85
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9.37
76
760.
7723
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47E
+06
0.00
0008
0.01
10.
0445
230.
0516
564.
80.
2137
080.
0077
112
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330.
4675
45(8
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Thh
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/Oifi
1515
054
1126
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033
100
867
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atio
n S
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m L
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(8)
Loss
Thr
ough
Diff
user
/Orif
ice
1515
0.54
1126
27.9
6033
1.00
867
(9)
Diff
user
Fou
ling
Loss
1414
0.50
5051
41.9
6033
1.51
3721
Tota
l Blo
wer
Pip
ing
Dis
char
ge L
osse
s =
1.51
psi
Cel
l Mfc
alc
base
d on
Sw
amee
Jai
n eq
uatio
nSt
atic
Pre
ssur
e =
5.63
psi
Cel
l Nhi
(inH
2O) P
ress
ure
VC
ell O
Dar
cy W
eisb
ach
Blo
wer
Dis
char
ge P
ress
ure
Req
uire
d =
7.14
psi
(1)
16" B
low
er O
utle
t1
Che
ck V
alve
, 1 B
FV, 1
4' x
16"
Exp
.(2
)30
" Air
Pip
ing
1 90
Ben
d, 4
thru
tees
(3)
24" A
ir P
ipin
g30
" x 2
4" c
ontra
ctio
n, 2
90
bend
s, 1
thru
tee
(4)
20" A
ir P
ipin
g24
" x 2
0" c
ontra
ctio
n, 1
thru
tee
(5)
14" A
ir P
ipin
g1
thru
tee,
1 9
0 be
nd, v
entu
ri m
eter
, mod
ulat
ing
valv
e 10
deg
clo
sed
(6)
12" A
ir P
ipin
g/D
iff. H
ead
2 te
es, 2
90
deg
bend
s(7
)6"
Air
Pip
ing
(8)
Loss
Thr
ough
Diff
user
Bas
ed o
n 13
/64"
orif
ice
Silv
er S
erie
s II
Diff
user
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iffus
er L
oss
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geR
ecom
men
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anita
ire
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170
3.3 SYSTEM DESIGN - SYSTEM CURVEThis spreadsheet displays the system curve of the aeration blower piping system. The data is poltted on graphs on the following spreadsh
SCFM PSI0 5.63
1000 5.632000 5.643000 5.654000 5.675000 5.706000 5.737000 5.768000 5.819000 5.85
10000 5.9011000 5.9612000 6.0313000 6.1014000 6.1715000 6.2516000 6.3417000 6.4318000 6.5319000 6.6320000 6.7421000 6.8522000 6.9723000 7.0924000 7.2225000 7.36
y�=�2.77E�09x2 +�1.73E�18x�+�5.63E+00R²�=�1.00E+00
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
0 5000 10000 15000 20000 25000 30000
Series1
Poly.�(Series1)
171
3.4 SYSTEM DESIGN - BLOWER DESIGNThis spreadsheet details the multiple temperature, pressure, and flow related conditions that are taken into account to correctly size the blowers.
Historical Weather Data for West Palm BeachData Source Parameter Value
ASHRAE Extreme (1%) Conditions for WPB
#VALUE! 80
NOAA Records for West Palm Beach
Maximum Temperature (°F): 101
Resulting Relative Humidity*: 41%
Blower Inlet and Discharge Pressures From 5th Order Curve Fit of Stephenson/Nixon, Ambient Barometric Pressure (psia) 14.696 Figure 4-1 - Saturation Water Vapor Pressure,Blower Inlet Pressure (psia) 14.53 Water vapor pressure (psi) vs temperature (°F) can System Design Pressure Loss (psig): 7.14 be calculated with the following formula:Estimated Discharge Pressure (psia ): 21.84 VP = a*T5 +�b*T4 +�c*T3�+�d*T2�+�e*T�+�f
Where:Correct Blower Florate Design Point for Extreme Hot Weather Condition a = 2.27E-11 32°F � T � 140°FParameter Std. Cond. Design b = -2.5E-10Inlet Temperature (°F): 68.0 101.0 c = 5.08E-07Absolute Inlet Temperature (°R): 528 561 d = 7.42E-06Relative Humidity: 36% 41% e = 0.001485Vapor Pressure (psi): 0.3390 0.9781 --------------> f = 0.016274Barometric Pressure (psi): 14.70 14.53Density Correction Factor (ICFM/SCFM): 1.00 1.10 -------------->Maximum Day Air Flow (CFM): 23,368 25,604
Correct Blower Pressure Design Point for Extreme Hot Weather Conditionk-1/k 0.283 0.283Approximate Site Discharge Pressure (psig): 7.14Equivalent Air Pressure (EAP) (psig): 7.92 -------------->
Size Blowers Additional InformationMinimum Mixing Air Flow (SCFM): 5,202Average Annual Air Flow (SCFM), not nitrifying: 13,268 14,538 icfmMaximum Month Air Flow (SCFM), not nitrifying: 15,211 16,667 icfmMaximum Day Air Flow (SCFM), not nitrifying: 22,053 24,163 icfmConversion Factor (ICFM/SCFM): 1.10Number of Blowers: 4
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Ratio of Large To Small 1.5Small Blower Capacity (ICFM): (1 x) 5,000 4,563 SCFM 23728.7277Large Blower Capacity (ICFM): (3 x) 7,000 6,389 SCFMFirm Blower Capacity (ICFM): 12,000Is Max. Month Requirement met w/ Firm Capacity? NoRequired Blower Turn Down to Meet Minimum Flow: 25.7%Site Barometric Pressure (psia): 14.70Small Blower Rating Point (SCFM) 5,000 @ 7.92 psig 200 HP Large Blower Rating Point (SCFM) 7,000 @ 7.92 psig 300 HP
=IF(C38=2,ROUND(D36/2.5,-2),IF(C38=3,ROUND(D36/3.5,-2),IF(C38=4,ROUND(D36/5.5,-2),IF(C38=5,ROUND(D36/7,-2),0))))
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172
4.0 - COST ESTIMATE - SUMMARYThis spreadsheet summarizes the results of the capital cost estimate in spreadsheets 4.1 - 4.7
Item ECM�No.�1 ECM�No.�2 ECM�No.�3 Comments/SourceDemolition $52,271 $52,271 $52,271 Spreadsheet�8.1Blowers #VALUE! $748,750 $748,750 Spreadsheet�8.2Diffusers $432,000 $432,000 $432,000 Spreadsheet�8.3Structural���Blower�Building $76,481 $76,481 $76,481 Spreadsheet�8.4Mechanical���Piping $334,214 $334,214 $334,214 Spreadsheet�8.5Instrumentation $69,000 $69,000 $319,125 Spreadsheet�8.6Electrical $155,387 $155,387 $207,348 Spreadsheet�8.7
SubTotal�1 #VALUE! $1,868,103 $2,170,189
Contractor�OH&P #VALUE! $280,215 $325,528 15%���Based�on�prevailing�ratesMobilization/Demobilization #VALUE! $93,405 $108,509 5%���Based�on�prevailing�rates
Subtotal�2 #VALUE! $2,241,724 $2,604,226
Performance�Bond #VALUE! $22,417 $26,042 1%Insurance #VALUE! $11,209 $13,021 0.5%���Higher�end�of�01�31�13.30Permits #VALUE! $22,417 $26,042 1%���Mid�range�"rule�of�thumb",�01�41�26.50
Subtotal�3 #VALUE! $2,297,767 $2,669,332
Contingency #VALUE! $229,777 $266,933 10%���01�21�16.50���Preliminary�Working�Drawing�StageEngineering�Fee�(design�and�construction�administration�based�on�subtotal�1) #VALUE! $280,215 $325,528 15%���Based�on�prevailing�rates
Grand�Total #VALUE! $2,807,759 $3,261,794AACE�Class�4�Low�Range�(�20%) #VALUE! $2,250,000 $2,610,000AACE�Class�4�Hi�Range�(+30%) #VALUE! $3,650,000 $4,240,000
173
4.1
- CO
ST E
STIM
ATE
- D
EMO
LITI
ON
WPB
�City
SOURC
EDESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
M�No.
Mat�In
dex
0.964
DEM
OLITION
WPB
�City
Kelly�Tractor�Quo
te#V
ALU
E!2
MO
$10,000.0 0
$20,000
1La
bor I
ndex
PIPING
0.699
22�05�05.10�215 5
Piping,�m
etal�24"���26"�dia.
200LF
$19.20
$1.02
$14.44
$2,88 8
122�05�05.10�215 3
Piping,�m
etal�16"���20"�dia.
250LF
$15.10
$0.80
$11.35
$2,839
1
22�05�05.10�2162
Plastic�pipe�w/�fittin
gs,�2"��3"�dia.�
(diffusers)
2300
LF$1.87
$1.31
$3,006
1DIP�pipe�weight
6.4TO
NS
$0.00
1MEC
HANICAL�AER
ATO
RRe
move�Mech�Aerator
9EA
$500.00
$349.50
$3,146
1Mechanical�A
erator�W
eight�X
�94.5TO
NS
$01
26�05�05.25�1070
Dem
olish�10
0�HP�Motor�and
�electrical
9EA
$218.00
$152.38
$1,371
1
BLOWER
�SHELTER
02�41�16.17�1080
Footings,�Con
crete,�1'�6
"�thick,�2'�w
ide
120LF
$7.45
$4.34
$9.55
$1,146
102�41�16.17�120 0
�����A
verage�Reinforcing,�add
�10%
120LF
$0.75
$0.43
$0.95
$115
102�41�16.17�2420
Concrete,�plain�con
crete,�8"�thick
672SF
$8.75
$1.37
$7.49
$5,031
102�41�16.17�260 0
�����A
verage�Reinforcing,�add
�10%
672SF
$0.88
$0.14
$0.75
$503
1
02�41�16.13�0600
Small�bldgs,�con
crete,�incl�20�mi�haul,�no
�foun
datio
n�or�dum
p�fees
470CF
$0.14
$0.17
$0.27
$126
1
02�41�19.18�0300
Selective�Dem
olition
,�Dispo
sal�O
nly,�
loading�and�5�mi�haul�to�du
mp
59.5
CY$4.25
$5.20
$8.17
$486
1�����A
dd�50%
�for�20�m
i�haul
59.5
CY$2.13
$2.60
$4.09
$243
1
02�41�19.19�0100
Selective�Dem
olition
,�Dum
p�Ch
arges,�
tipping�fe
es�only,�(assum
�CY�=�TO
N)
59.5
TON
$95.00
$91.58
$5,448
1
26�05�05.25�1090
Dem
olish�20
0�HP�Motor�and
�electrical
3EA
$585.00
$408.92
$1,227
1
Aeration�ba
sin�cond
uit�o
n�ba
sins�and
�cable�f�M
CCs
26�05�05.10�010 0
Dem
olish�RG
S�Co
nduit,�1/2"���1
"1000
LF$1.62
$1.13
$1,132
126�05�05.10�012 0
Dem
olish�RG
S�Co
nduit,�1�1/4"���2
"1000
LF$1.96
$1.37
$1,37 0
126�05�05.10�030 0
Dem
olish�armored
�cable,�2�#�12
2000
LF$0.65
$0.45
$909
126�05�05.10�029 0
Dem
olish�armored
�cable,�3�#�14
2000
LF$0.69
$0.48
$965
126�05�05.10�187 0
Dem
olish�cable,�#6�GND
2000
LF$0.12
$0.08
$168
1
Blow
er�con
duit�and
�cab
le�f�MCC
�to�
Blow
er26�05�05.10�1990
Dem
olish�50
0�MCM
�cable
300lf
$0.49
$0.34
$103
116�05�05.10�191 0
Dem
olish�1�#1/0�cable
300lf
$0.24
$0.17
$50
1Sum
ECM�No.�1
$52,271
ECM�No.�2
$52,271
ECM�No.�3
$52,271
174
4.2
- CO
ST E
STIM
ATE
- B
LOW
ERS
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
I�No.�
BLOWER
S(3)�3
00�HP�Bo
wers
3EA
$159,00 0
$39,750
$198,750
$596,250
2(1)�2
00�HP�Blow
er1EA
$122,00 0
$30,500
$152,500
$152,500
2
Total
$748,750
COMPA
RABLE�MULTI�S
TAGE�CE
NTR
IFUGAL�CO
ST(3)�3
00�HP�Blow
ers
3EA
$110,00 0
$27,500
$137,500
$412,500
1(1)�2
00�HP�Blow
ers
1EA
$98,000
$24,500
$122,500
$122,500
1
Total
$535,000
Sum
ECM�No.�1
$535,00 0
ECM�No.�2
$748,750
ECM�No.�3
$748,750
Blow
er�Cost�D
ata
HP
Budget�$
Source
Average
HP
Budget�$
Source
Average
50$56,000
EPA
250
$180,000
EPA
Ratio
200
1.24
50$102,00 0
EPA
250
$151,000
Rohrbache
250
1.89
75$75,000
EPA
$75,000
250
$165,000
Rohrbache
300
1.45
100
$115,00 0
EPA
250
$168,000
Rohrbache
400
1.80
100
$93,000
Rohrbacher,�et.�al
250
$188,000
Rohrbache
500
1.61
150
$120,00 0
EPA
300
$175,000
EPA
1.60
150
$134,00 0
Rohrbacher,�et.�al
300
$142,000
EPA
200
$120,00 0
EPA
300
$119,000
Rohrbache
200
$160,00 0
EPA
300
$119,000
Rohrbache
200
$86,000
Rohrbacher,�et.�al
300
$143,000
Rohrbache
200
$90,000
Rohrbacher,�et.�al
300
$156,000
Rohrbache
200
$93,000
Rohrbacher,�et.�al
300
$208,000
Rohrbache
200
$124,00 0
Rohrbacher,�et.�al
300
$209,000
Rohrbache
200
$128,00 0
Rohrbacher,�et.�al
400
$275,000
EPA
200
$176,00 0
Rohrbacher,�et.�al
400
$132,000
Rohrbache
400
$198,00 0
Rohrbache
500
$325,00 0
EPA
$325,000
MULTI_STAGE�CE
NTR
IFUGAL�CO
STS
HP
Budget�$
Source
Average
200
$98,000H&S
$98,000
250
$90,000H&S
$90,000
300
$153,000
H&S
300
$72,000H&S
300
$104,00 0
H&S
350
$110,00 0
H&S
$110,000
400
$135,000
H&S
400
$88,000H&S
500
$245,00 0
H&S
500
$170,00 0
H&S
500
$190,00 0
H&S
$110,000
$112,000
$202,000
$170,000
$104,000
$127,000
$159,000
$122,000
$202,000
$79,000
175
4.3
- CO
ST E
STIM
ATE
- D
IFFU
SER
S
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Factor
Total�U
nit
TOTA
LEC
I�No.
DIFFU
SERS
Equipm
ent
1LS
3200
001.35
4320
00$4
32,000
Aqu
arius�qu
ote
Sum
ECM�No.�1
$432
,000
ECM�No.�2
$432
,000
ECM�No.�3
$432
,000
176
4.4
- CO
ST E
STIM
ATE
- ST
RU
CTU
RA
LWPB
�City
WPB
�City
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
otal�Unit�C
oTO
TAL
ECI�N
o.Mat�In
dex
Labo
r Ind
exBLOWER
�BUILDING�CONSTRU
CT98.10%
78.10%
03�41�33
.60�22
00Precast�T
ees,�Dou
ble�Tees,�R
oof�M
embe
rs,�Std.�
Weight,�12"�x�8'�w
ide,�30'�span
9EA
$1,575
$138
$86
$1,738
$15,645
103
�30�53
.40�08
2016
"�x�16
",�Avg.�R
einforcing
9.4CY
$455
$610
$60
$983
$9,238
103
�30�53
.40�39
40Footings,�strip,�24"�x�12",�reinforced
9.3CY
$133
$86
$1$1
98$1,839
103
�30�52
.40�40
50Foun
datio
n�mat,�over�20
�C.Y.
42.2
CY$1
97$1
06$1
$277
$11,676
104�22�10.28�0300
Concrete�Block,�H
igh�Sten
gth,�350
0�psi,�8"�th
ick
2260
SF$3
$4$6
$14,479
103
�30�53
.40�35
70Equipm
ent�P
ads,�6'�x�6'�x�8"�Thick
5EA
$157
$129
$2$2
57$1,283
103
�30�53
.40�35
50Equipm
ent�P
ads,�4'�x�4'�x�8"�Thick
5EA
$67
$61
$1$1
14$569
107
�26�10
.10�07
00Po
yethylen
e�Va
por�Ba
rrier,�Stand
ard,�.004
"�Thick
21.2
100�SF
$3$8
$9$200
1
31�23�16
.16�60
70Structura l�Excavation�for�Minor�Structures,�Sand,�3/4�
CY�Bucket
200CY
$6$6
$10
$1,990
131
�23�23
.13�19
00Dozer�Backfill,�bulk
100CY
$0$1
$2$157
131
�23�23
.13�22
00Co
mpact�Backfill,�12"�lifts
200CY
$1$2
$3$510
108
�11�63
.23
Storm�Doo
r,�Clear�Ano
dic�Co
ating,�7'0"�x�3'�wide
2EA
$266
$48
$299
$597
108
�33�23
.10�01
00Ro
lling�Service�Doo
r,�10'�x�10'�high
1EA
$1,675
$490
$2,026
$2,026
123
�37�23
.10�11
00HVA
C�Louvers,�Stand
ard�8"�x�5"
336EA
$31
$15
$42
$14,181
109
�24�23
.40�10
00Exterior�Stucco,�w/�bo
nding�agen
t83
.7SY
$4$7
$1$9
$776
1
09�91�13
.60�16
00Paint�S
tucco,�rou
gh,�oil�base,�paint�2�coats,�spray
2260
SF$0
$0$0
$606
109
�91�23
.72�28
80Paint�C
MU�Interior,�paint�2�coats,�spray
2260
SF$0
$0$0
$708
1Sum
ECM�No.�1
$76,481
177
4.1
- CO
ST E
STIM
ATE
- D
EMO
LITI
ON
WPB
�City
SOURC
EDESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
M�No.
Mat�In
dex
0.964
DEM
OLITION
WPB
�City
Kelly�Tractor�Quo
te#V
ALU
E!2
MO
$10,000.0 0
$20,000
1La
bor I
ndex
PIPING
0.699
22�05�05.10�215 5
Piping,�m
etal�24"���26"�dia.
200LF
$19.20
$1.02
$14.44
$2,88 8
122�05�05.10�215 3
Piping,�m
etal�16"���20"�dia.
250LF
$15.10
$0.80
$11.35
$2,839
1
22�05�05.10�2162
Plastic�pipe�w/�fittin
gs,�2"��3"�dia.�
(diffusers)
2300
LF$1.87
$1.31
$3,006
1DIP�pipe�weight
6.4TO
NS
$0.00
1MEC
HANICAL�AER
ATO
RRe
move�Mech�Aerator
9EA
$500.00
$349.50
$3,146
1Mechanical�A
erator�W
eight�X
�94.5TO
NS
$01
26�05�05.25�1070
Dem
olish�10
0�HP�Motor�and
�electrical
9EA
$218.00
$152.38
$1,371
1
BLOWER
�SHELTER
02�41�16.17�1080
Footings,�Con
crete,�1'�6
"�thick,�2'�w
ide
120LF
$7.45
$4.34
$9.55
$1,146
102�41�16.17�120 0
�����A
verage�Reinforcing,�add
�10%
120LF
$0.75
$0.43
$0.95
$115
102�41�16.17�2420
Concrete,�plain�con
crete,�8"�thick
672SF
$8.75
$1.37
$7.49
$5,031
102�41�16.17�260 0
�����A
verage�Reinforcing,�add
�10%
672SF
$0.88
$0.14
$0.75
$503
1
02�41�16.13�0600
Small�bldgs,�con
crete,�incl�20�mi�haul,�no
�foun
datio
n�or�dum
p�fees
470CF
$0.14
$0.17
$0.27
$126
1
02�41�19.18�0300
Selective�Dem
olition
,�Dispo
sal�O
nly,�
loading�and�5�mi�haul�to�du
mp
59.5
CY$4.25
$5.20
$8.17
$486
1�����A
dd�50%
�for�20�m
i�haul
59.5
CY$2.13
$2.60
$4.09
$243
1
02�41�19.19�0100
Selective�Dem
olition
,�Dum
p�Ch
arges,�
tipping�fe
es�only,�(assum
�CY�=�TO
N)
59.5
TON
$95.00
$91.58
$5,448
1
26�05�05.25�1090
Dem
olish�20
0�HP�Motor�and
�electrical
3EA
$585.00
$408.92
$1,227
1
Aeration�ba
sin�cond
uit�o
n�ba
sins�and
�cable�f�M
CCs
26�05�05.10�010 0
Dem
olish�RG
S�Co
nduit,�1/2"���1
"1000
LF$1.62
$1.13
$1,132
126�05�05.10�012 0
Dem
olish�RG
S�Co
nduit,�1�1/4"���2
"1000
LF$1.96
$1.37
$1,37 0
126�05�05.10�030 0
Dem
olish�armored
�cable,�2�#�12
2000
LF$0.65
$0.45
$909
126�05�05.10�029 0
Dem
olish�armored
�cable,�3�#�14
2000
LF$0.69
$0.48
$965
126�05�05.10�187 0
Dem
olish�cable,�#6�GND
2000
LF$0.12
$0.08
$168
1
Blow
er�con
duit�and
�cab
le�f�MCC
�to�
Blow
er26�05�05.10�1990
Dem
olish�50
0�MCM
�cable
300lf
$0.49
$0.34
$103
116�05�05.10�191 0
Dem
olish�1�#1/0�cable
300lf
$0.24
$0.17
$50
1Sum
ECM�No.�1
$52,271
ECM�No.�2
$52,271
ECM�No.�3
$52,271
178
4.2
- CO
ST E
STIM
ATE
- B
LOW
ERS
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
I�No.�
BLOWER
S(3)�3
00�HP�Bo
wers
3EA
$159,00 0
$39,750
$198,750
$596,250
2(1)�2
00�HP�Blow
er1EA
$122,00 0
$30,500
$152,500
$152,500
2
Total
$748,750
COMPA
RABLE�MULTI�S
TAGE�CE
NTR
IFUGAL�CO
ST(3)�3
00�HP�Blow
ers
3EA
$110,00 0
$27,500
$137,500
$412,500
1(1)�2
00�HP�Blow
ers
1EA
$98,000
$24,500
$122,500
$122,500
1
Total
$535,000
Sum
ECM�No.�1
$535,00 0
ECM�No.�2
$748,750
ECM�No.�3
$748,750
Blow
er�Cost�D
ata
HP
Budget�$
Source
Average
HP
Budget�$
Source
Average
50$56,000
EPA
250
$180,000
EPA
Ratio
200
1.24
50$102,00 0
EPA
250
$151,000
Rohrbache
250
1.89
75$75,000
EPA
$75,000
250
$165,000
Rohrbache
300
1.45
100
$115,00 0
EPA
250
$168,000
Rohrbache
400
1.80
100
$93,000
Rohrbacher,�et.�al
250
$188,000
Rohrbache
500
1.61
150
$120,00 0
EPA
300
$175,000
EPA
1.60
150
$134,00 0
Rohrbacher,�et.�al
300
$142,000
EPA
200
$120,00 0
EPA
300
$119,000
Rohrbache
200
$160,00 0
EPA
300
$119,000
Rohrbache
200
$86,000
Rohrbacher,�et.�al
300
$143,000
Rohrbache
200
$90,000
Rohrbacher,�et.�al
300
$156,000
Rohrbache
200
$93,000
Rohrbacher,�et.�al
300
$208,000
Rohrbache
200
$124,00 0
Rohrbacher,�et.�al
300
$209,000
Rohrbache
200
$128,00 0
Rohrbacher,�et.�al
400
$275,000
EPA
200
$176,00 0
Rohrbacher,�et.�al
400
$132,000
Rohrbache
400
$198,00 0
Rohrbache
500
$325,00 0
EPA
$325,000
MULTI_STAGE�CE
NTR
IFUGAL�CO
STS
HP
Budget�$
Source
Average
200
$98,000H&S
$98,000
250
$90,000H&S
$90,000
300
$153,000
H&S
300
$72,000H&S
300
$104,00 0
H&S
350
$110,00 0
H&S
$110,000
400
$135,000
H&S
400
$88,000H&S
500
$245,00 0
H&S
500
$170,00 0
H&S
500
$190,00 0
H&S
$110,000
$112,000
$202,000
$170,000
$104,000
$127,000
$159,000
$122,000
$202,000
$79,000
179
4.3
- CO
ST E
STIM
ATE
- D
IFFU
SER
S
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Factor
Total�U
nit
TOTA
LEC
I�No.
DIFFU
SERS
Equipm
ent
1LS
3200
001.35
4320
00$4
32,000
Aqu
arius�qu
ote
Sum
ECM�No.�1
$432
,000
ECM�No.�2
$432
,000
ECM�No.�3
$432
,000
180
4.4
- CO
ST E
STIM
ATE
- ST
RU
CTU
RA
LWPB
�City
WPB
�City
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
otal�Unit�C
oTO
TAL
ECI�N
o.Mat�In
dex
Labo
r Ind
exBLOWER
�BUILDING�CONSTRU
CT98.10%
78.10%
03�41�33
.60�22
00Precast�T
ees,�Dou
ble�Tees,�R
oof�M
embe
rs,�Std.�
Weight,�12"�x�8'�w
ide,�30'�span
9EA
$1,575
$138
$86
$1,738
$15,645
103
�30�53
.40�08
2016
"�x�16
",�Avg.�R
einforcing
9.4CY
$455
$610
$60
$983
$9,238
103
�30�53
.40�39
40Footings,�strip,�24"�x�12",�reinforced
9.3CY
$133
$86
$1$1
98$1,839
103
�30�52
.40�40
50Foun
datio
n�mat,�over�20
�C.Y.
42.2
CY$1
97$1
06$1
$277
$11,676
104�22�10.28�0300
Concrete�Block,�H
igh�Sten
gth,�350
0�psi,�8"�th
ick
2260
SF$3
$4$6
$14,479
103
�30�53
.40�35
70Equipm
ent�P
ads,�6'�x�6'�x�8"�Thick
5EA
$157
$129
$2$2
57$1,283
103
�30�53
.40�35
50Equipm
ent�P
ads,�4'�x�4'�x�8"�Thick
5EA
$67
$61
$1$1
14$569
107
�26�10
.10�07
00Po
yethylen
e�Va
por�Ba
rrier,�Stand
ard,�.004
"�Thick
21.2
100�SF
$3$8
$9$200
1
31�23�16
.16�60
70Structura l�Excavation�for�Minor�Structures,�Sand,�3/4�
CY�Bucket
200CY
$6$6
$10
$1,990
131
�23�23
.13�19
00Dozer�Backfill,�bulk
100CY
$0$1
$2$157
131
�23�23
.13�22
00Co
mpact�Backfill,�12"�lifts
200CY
$1$2
$3$510
108
�11�63
.23
Storm�Doo
r,�Clear�Ano
dic�Co
ating,�7'0"�x�3'�wide
2EA
$266
$48
$299
$597
108
�33�23
.10�01
00Ro
lling�Service�Doo
r,�10'�x�10'�high
1EA
$1,675
$490
$2,026
$2,026
123
�37�23
.10�11
00HVA
C�Louvers,�Stand
ard�8"�x�5"
336EA
$31
$15
$42
$14,181
109
�24�23
.40�10
00Exterior�Stucco,�w/�bo
nding�agen
t83
.7SY
$4$7
$1$9
$776
1
09�91�13
.60�16
00Paint�S
tucco,�rou
gh,�oil�base,�paint�2�coats,�spray
2260
SF$0
$0$0
$606
109
�91�23
.72�28
80Paint�C
MU�Interior,�paint�2�coats,�spray
2260
SF$0
$0$0
$708
1Sum
ECM�No.�1
$76,481
181
4.5
- CO
ST E
STIM
ATE
- M
ECH
AN
ICA
L PI
PIN
G
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total
TOTA
LEC
I�No.
2/08
�Felker�Bro12
"�30
4L�SS
180FT
6315
.75
78.75
$14,17
51
2/08
�Felker�Bro14
"�30
4L�SS
510FT
8020
100
$51,00
01
2/08
�Felker�Bro20
"�30
4L�SS
170FT
113
28.25
141.25
$24,01
31
2/08
�Felker�Bro24
"�30
4L�SS
130FT
178
44.5
222.5
$28,92
51
2/08
�Felker�Bro30
"�30
4L�SS
215FT
222
55.5
277.5
$59,66
31
2/08
�Felker�Bro30
"�x�14
"�Tee
5EA
2800
700
3500
$17,50
01
2/08
�Felker�Bro30
"�x�30
"�Tee
1EA
3000
750
3750
$3,750
12/08
�Felker�Bro30
"�x�24
"�Re
d1EA
900
225
1125
$1,125
12/08�Felker�Bro30"�x�30"�Elbo
w1EA
3246
811.5
4057
.5$4
,058
12/08�Felker�Bro30"�x�30
"�Blind�Fl
1EA
1000
250
1250
$1,250
12/08
�Felker�Bro20
"�x�14
"�Cross
2EA
3000
750
3750
$7,500
12/08
�Felker�Bro30
"�x�20
"�Re
d1EA
1500
375
1875
$1,875
12/08
�Felker�Bro24
"�x�24
"�Elbo
w2EA
3232
808
4040
$8,080
12/08
�Felker�Bro24
"�x�20
"�Re
d1EA
808
202
1010
$1,010
12/08
�Felker�Bro20
"�x�14
"�Tee
3EA
1500
375
1875
$5,625
12/08�Felker�Bro20"�x�14'�Red
1EA
900
225
1125
$1,125
12/08
�Felker�Bro14
"�x�14
"�Elbo
w1EA
400
100
500
$500
12/08
�Felker�Bro14
'�x�12"�Tee
9EA
2500
625
3125
$28,12
51
2/08
�Felker�Bro12
"�x�12
"�Elbo
w18
EA30
075
375
$6,750
1
30"�x�30
"�Exp.�Cou
p1EA
1500
1500
$1,500
124
"�x�24
"�Exp.�Cou
p1EA
1000
1000
$1,000
1Quo
te�f/�Vict
14"�Dep
endo
Lok
9EA
950
237.5
1187
.5$1
0,68
81
22�05�29
.10�017H
eavy�Duty�Wall�SS
104EA
298
14.3
312.3
$32,47
91
8'�Tall���304
�SS�Elevat
36EA
500
125
625
$22,50
01
Sum
Adjusted�material�cost�for�carbo
n�over�304
�SS�steel�price,�~5:1.�
ECM�No.�1
$334
,214
(f/�MEPS.com�ta
bles).��Assum
ing�supp
ort�is�50
�lb,�M
ay�201
0�$8
28�per
ECM�No.�2
$334
,214
�ton�steel�*50
/200
0�=�$2
0.7�for�material�x�1.5�factor�=�$31
�for�material
ECM�No.�3
$334
,214
$174
��$31
�+�$31
*5�=�$29
8�for�30
4�SS�sup
port
Quantity
�assum
es�sup
ports�every�10
',�18
�+�22*2�+�7*6�=�10
4Add
ed�30%
�to�labo
r�for�concrete�installatio
n
182
4.5
- CO
ST E
STIM
ATE
- M
ECH
AN
ICA
L PI
PIN
G
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total
TOTA
LEC
I�No.
2/08
�Felker�Bro12
"�30
4L�SS
180FT
6315
.75
78.75
$14,17
51
2/08
�Felker�Bro14
"�30
4L�SS
510FT
8020
100
$51,00
01
2/08
�Felker�Bro20
"�30
4L�SS
170FT
113
28.25
141.25
$24,01
31
2/08
�Felker�Bro24
"�30
4L�SS
130FT
178
44.5
222.5
$28,92
51
2/08
�Felker�Bro30
"�30
4L�SS
215FT
222
55.5
277.5
$59,66
31
2/08
�Felker�Bro30
"�x�14
"�Tee
5EA
2800
700
3500
$17,50
01
2/08
�Felker�Bro30
"�x�30
"�Tee
1EA
3000
750
3750
$3,750
12/08
�Felker�Bro30
"�x�24
"�Re
d1EA
900
225
1125
$1,125
12/08�Felker�Bro30"�x�30"�Elbo
w1EA
3246
811.5
4057
.5$4
,058
12/08�Felker�Bro30"�x�30
"�Blind�Fl
1EA
1000
250
1250
$1,250
12/08
�Felker�Bro20
"�x�14
"�Cross
2EA
3000
750
3750
$7,500
12/08
�Felker�Bro30
"�x�20
"�Re
d1EA
1500
375
1875
$1,875
12/08
�Felker�Bro24
"�x�24
"�Elbo
w2EA
3232
808
4040
$8,080
12/08
�Felker�Bro24
"�x�20
"�Re
d1EA
808
202
1010
$1,010
12/08
�Felker�Bro20
"�x�14
"�Tee
3EA
1500
375
1875
$5,625
12/08�Felker�Bro20"�x�14'�Red
1EA
900
225
1125
$1,125
12/08
�Felker�Bro14
"�x�14
"�Elbo
w1EA
400
100
500
$500
12/08
�Felker�Bro14
'�x�12"�Tee
9EA
2500
625
3125
$28,12
51
2/08
�Felker�Bro12
"�x�12
"�Elbo
w18
EA30
075
375
$6,750
1
30"�x�30
"�Exp.�Cou
p1EA
1500
1500
$1,500
124
"�x�24
"�Exp.�Cou
p1EA
1000
1000
$1,000
1Quo
te�f/�Vict
14"�Dep
endo
Lok
9EA
950
237.5
1187
.5$1
0,68
81
22�05�29
.10�017H
eavy�Duty�Wall�SS
104EA
298
14.3
312.3
$32,47
91
8'�Tall���304
�SS�Elevat
36EA
500
125
625
$22,50
01
Sum
Adjusted�material�cost�for�carbo
n�over�304
�SS�steel�price,�~5:1.�
ECM�No.�1
$334
,214
(f/�MEPS.com�ta
bles).��Assum
ing�supp
ort�is�50
�lb,�M
ay�201
0�$8
28�per
ECM�No.�2
$334
,214
�ton�steel�*50
/200
0�=�$2
0.7�for�material�x�1.5�factor�=�$31
�for�material
ECM�No.�3
$334
,214
$174
��$31
�+�$31
*5�=�$29
8�for�30
4�SS�sup
port
Quantity
�assum
es�sup
ports�every�10
',�18
�+�22*2�+�7*6�=�10
4Add
ed�30%
�to�labo
r�for�concrete�installatio
n
183
4.6
- CO
ST E
STIM
ATE
- IN
STR
UM
ENTA
TIO
N
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total
TOTA
LEC
I�No.
DO�Probe
�and
�Transmitter
CC�Con
trols�Quo
te���L.�Garcia���
9/16
/10
Alum�Pipe�Stand�Mou
nt�w/�
sunshield,�NEM
A�4X�bo
x,�(1
)�24�V�+�
(1)�1
20�V�surge�sup
pressor,�to
ggle�
switch,�wiring
627
5068
7.5
3437
.5$2
0,62
5.00
3
Hach�List�Price
Hach�SC�100
�Con
troller,�((3(�2�probe
�controllers,�(3)�1�probe
�con
trollers)
613
5033
7.5
1687
.5$1
0,12
5.00
3Hach�List�Price
LDO�Probe
915
1037
7.5
1887
.5$1
6,98
7.50
3Hach �List� Price
115�V �Air�Blast�Cleaning�System
980
020
010
00$9
,000
.00
3Hach�List�Price
Pole�M
ount�Kit
938
095
475
$4,275
.00
3
Mod
ulating�BF
V6/09
�Dezurik�Quo
te14
"�Mod
ulating�BFV
968
0017
0085
00$7
6,50
0.00
3
CC�Con
trols�Quo
te���L.�Garcia���
9/16
/10
NEM
A�4X�bo
x,�(1
)�24�V�+�(1)�1
20�V�
surge�supp
ressor,�toggle�sw
itch,�
wiring
922
0055
027
50$2
4,75
0.00
3SS�Unistrut�M
ount
950
12.5
62.5
$562
.50
3
Differen
tial�Pressure�Indicators�(Flow�M
eter)
5/09
�PFS�Quo
te14
"�Ve
nturi�Flow�Elemen
t9
3300
825
4125
$37,12
5.00
310
/08�PFS�Quo
te`
Pressure�Indicatin
g�Transm
itter
1818
0045
022
50$4
0,50
0.00
3CC
�Con
trols�Quo
te���L.�Garcia���
9/16
/10
Alum�Pipe�Stand�Mou
nt�w/�sunshield
965
016
2.5
812.5
$7,312
.50
3Amerispo
nse.com,�9/19/10
4�20
�ma�Surge�Supp
ressor
1810
526
.25
131.25
$2,362
.50
3
PLC�an
d�Programming
Job�of�sim
ilar�scop
e/scale,�1/11
Programmab
le�Logic�Con
troller
1LS
5000
050
000
$25,00
0.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Software
1LS
3000
3000
$1,500
.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Training/Calibratio
n/Docum
ents
1LS
1000
010
000
$5,000
.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Programming�and�Trou
blesho
oting
1LS
1500
015
000
$7,500
.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Spare�Parts
1LS
1000
010
000
$5,000
.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
HMI�Program
ming�and�Re
ports
1LS
5000
050
000
$25,00
0.00
1/3
Sum
ECM�No.�1
$69,00
0.00
ECM�No.�2
$69,00
0.00
ECM�No.�3
$319
,125
.00
184
4.7
- CO
ST E
STIM
ATE
- EL
ECTR
ICA
LWPB
�City
WPB
�City
DIVISION�NO
DESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total
INSTALLATION
TOTA
LEC
I�No.�
Mat�In
dexLab
or�In
dex
Motor�Related
98.10%
78.10%
D5020�145�2520
Motor�Install,�200�HP
1EA
$12,500.00
$4,075.00
$15,445.08
$15,445.08
1interpolated
Motor�Install,�300�HP
3EA
$18,750.00
$6,112.00
$23,167.22
$69,501.67
1D5020�145�0240
Motor�Install,�1�HP
1EA
$700.00
$890.00
$1,381.79
$1,381.79
1Bu
ilding�Internal
15445.08
D5025�120�1160
14�Recep
tacles/2,000�sf
2117
SF$0.56
$1.95
$2.07
$4,387.08
169501.67
D5025�120�1280
Light�S
witche
s/4�sw
itche
s2117
SF$0.10
$0.35
$0.37
$786.36
11381.79
D5020�208�0680
Lightin
g,�Fluroescent�Fixtures
2117
SF$2.33
$4.88
$6.10
$12,907.37
126�24�16.30
Pane
lboard
1EA
$735.00
$605.00
$1,193.54
$1,193.54
1Wiring
26�05�19.90�3280
#350�XHHW�(6
�per�300�HP)
900LF
$8.45
$2.18
$9.99
$8,992.83
126�05�19.35�1400
��Terminate�#35 0
18EA
$51.00
$85.00
$116.42
$2,095.49
126�05�19.90�33200#500�XHHW�(3
�per�200�HP)
150LF
$14.00
$3.00
$16.08
$2,411.55
126�05�19.35�1500
��Terminate�#50 0
3EA
$66.00
$98.00
$141.28
$423.85
126�05�26.80�0700
#1�GND
350LF
$1.66
$0.87
$2.31
$807.78
126�05�19.35�0750
��Terminate�#1
7EA
$10.90
$35.50
$38.42
$268.93
126�05�19.90�3140
#13540
LF$2.74
$0.98
$3.45
$12,224.75
326�05�19.35�0750
��Terminate�#1
18EA
$10.90
$35.50
$38.42
$691.53
326�05�19.90�3120
#2200LF
$2.14
$0.87
$2.78
$555.76
126�05�19.35�0750
��Terminate�#2
4EA
$8.65
$32.50
$33.87
$135.47
126�05�19.90�3120
#21770
LF$2.14
$0.87
$2.78
$4,918.49
326�05�19.35�0750
��Terminate�#2
9EA
$8.65
$32.50
$33.87
$304.81
326�05�23.10�0020
2�#12
1770
LF$0.18
$0.44
$0.52
$920.79
326�05�23.10�0030
3�#12
1770
LF$0.25
$0.49
$0.63
$1,111.45
326�05�26.80�0330
#12�GND
3540
LF$0.11
$0.30
$0.34
$1,211.42
326�05�19.35�1630
��Terminate�#12
63EA
$0.58
$7.85
$6.70
$422.09
326�05�23.10�0300
8�#14
200LF
$0.67
$0.74
$1.24
$247.04
126�05�26.80�0320
#14�GND
400LF
$0.07
$0.28
$0.29
$114.94
126�05�19.35�1620
��Terminate�#14
32EA
$0.43
$6.55
$5.54
$177.20
126�05�26.80�0320
#14�GND
5310
LF$0.07
$0.28
$0.29
$1,525.83
326�05�19.35�1620
��Terminate�#14
27EA
$0.43
$6.55
$5.54
$149.51
3Co
nduit
26�05�33.05�0700
1"�Con
duit,�Alum
500LF
$4.30
$4.90
$8.05
$4,022.60
126�05�33.05�0700
1"�Con
duit,�Alum
3540
LF$4.30
$4.90
$8.05
$28,480.01
326�05�33.05�1100
3"�Con
duit,�Alum
450LF
$22.50
$8.70
$28.87
$12,990.24
133�77�19.17�0800
Concrete�Handh
oles
2EA
$510.00
$582.50
$955.24
$1,910.49
133�17�19.17�7000
Ductbank�and�Co
nduit,�10��@
50LF
$171.25
$39.25
$198.65
$9,932.53
133�71�19.17�7830
Concrete�(1
5�CY
/100�LF)
50LF
$1.61
$0.72
$2.14
$107.09
133�71�19.17�7860
Reinforcing�(10�Lb/LF)
50LF
$4.00
$3.40
$6.58
$328.97
1Exterior�Groun
ding/Lightning�Protection
26�05�26.80�0130
Groun
ding�Rod
s,�cop
per
8EA
$92.00
$98.00
$166.79
$1,334.32
126�05�26.80�1000
4/0�Groun
ding
320LF
$3.85
$1.38
$4.85
$1,553.48
126�41�13.13�0500
Air�Terminals
10EA
$24.50
$49.00
$62.30
$623.04
126�41�13.13�2500
Alum�Cable
270LF
$0.85
$1.40
$1.93
$520.36
126�41�13.13�3000
Arrestor
2EA
$78.50
$49.00
$115.28
$230.56
1Sum
ECM�No.�1
$155,387.37
ECM�No.�2
$155,387.37
ECM�No.�3
$207,348.06
185
5.0
- O&
M C
OST
S
Plant�Labor�Rate
Discoun
t�Rate�(in
terest)
CPI
Real�Rate
Planning�
Period
�(years)
36.45
0.047
0.025
0.022
20
Equipm
ent
O&M�Item
Cost
Amou
nt�
Unit
Ann
ual
NPV
ECM
Source
Diffusers
Replace�Mem
branes
$9.04
10500EA
$11,862
$190,26 4
1,2,3
Sanitaire,�5/m
in�per�diffuser,�$6�replacem
ent�cost,�7�10�year�inter
Blow
ers
Replace�Filte
rs,�Inspe
ctio
$2,500
4EA
$10,000
$160,402
2,3
Rohrbacher�et.�al
LDO�Probe
sRe
place�Sensor�Caps
$140
9EA
$1,26 0
$20,211
3Article:�"DO"ing�m
ore�with
�Less,�List�P
rice:�H
ach
Diffusers
Clean�Mem
branes
$36
60HR
$2,18 7
$35,080
1,2,3
Rosso,�Econo
mic�Im
plications�of�Fine�Po
re�Diffuser�Aging
Multi�Stage�Blow
ers
Typical�O
&M�based
�on�1
$1,50 0
4$6,000
$96,241
11.5%
�Capita
l�Cost,�per�Roh
rbache
r�et.�al
Equipm
ent
O&M�Item
Cost
Amou
nt�
Ann
ual
NPV
ECM
Source
Manual�D
OCo
llect�DO�M
anually
�$55
365
�$19
,95 6
�$320,104
3City�of�B
oca�Ra
ton
Mech�Diffuser�M
otors
Service�Motors
�$1,000
9�$9,000
�$144,362
1,2,3
City�of�B
oca�Ra
ton
Multi�Stage�Blow
ers
Typical�O
&M�based
�on�1
�$1,500
3�$4,500
�$72,181
2,3
1.5%
�Capita
l�cost,�per�Roh
rbache
r�et.�al
Diffusers
Replace�Mem
branes
�$9
215
�$1,943
�$31,16 7
1,2,3
City�of�B
oca�Ra
ton,�rep
lace�25%
�of�d
iffusers�pe
r�basin�each�year
Sum
Sum
Ann
ual
NPV
ECM��N
o.�1
$9,10 6
$146,056
ECM��N
o.�2
$8,606
$138,036
ECM��N
o.�3
�$10,091
�$161,857
Equipm
ent
Useful�Life
Remaining�Rep
lacemeAmou
nt�
Total
NPV
Source
200�HP�Multi�Stage�Ce
ntrif u
205
�$122,500
3�$367,500
�$329,612
1,2,3
Quo
te�fo
r�200�HP�+�25%�installatio
n200�HP�Motor�Starters
205
�$21,55 0
3�$64,650
�$57,985
1,2,3
RS�M
eans�26�24�19.40�0600
100�HP�Electric�M
otors
201000
�$9,325
9�$83,925
$01,2,3
RS�M
eans�26�71�13.10�5260�+�26�71�13.20�2100
100�HP�Motor�Starters
205
�$6,425
9�$57,825
�$51,863
1,2,3
RS�M
eans�26�24�19.40�0500
Replace�Aerators
205
�$100,000
9�$1,248,146
�$1,119,466
1,2,3
6/17/11�Quo
te�f/�TSC�Ja
cobs
Sum
NPV
ECM��N
o.�1��$1,558,926
ECM��N
o.�2
�$1,558,926
ECM��N
o.�3
�$1,558,926
O&M�No�Longer�Neccesary
O&M�Costs
Equipm
ent�R
eplacemen
t�Costs�Avoided
186
5.1
- O&
M C
OST
S - R
EPLA
CE
AER
ATO
RS
WPB
�City
WPB
�City
SOURC
EDESCR
IPTION
QUANTITY
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
M�No.
Mat�In
dexL
abor
Inde
x0.964
0.69
9
Kelly�Tractor�Quo
teCR
ANE�RE
NTA
L���4
0�TO
N�CAPA
CIT Y
3MO
$10,00
0.00
$30,000
Remove�Mech�Aerator
9EA
$500
.00
$349
.50
$3,146
Mechanical�A
erator�W
eight�X
�94.5
TONS
$0New
�Mechanical�A
erators
9EA
1000
0035
000
1350
00$1
,215
,000
Sum
ECM�No.�1
$1,248
,145
.50
187
6.0 LIFE-CYCLE COST ANALYSIS INPUTS
CurrentCost per
kwH
Bond Rate CPI Inflation
Real Rate (interest)
EnergyInflation
PlanningPeriod(years)
TotalCurrent
HP0.07 0.047 0.025 0.022 0.00083 20 558.5
PowerFactor
If no Amp draws,
assumed% of
Nameplate
AvgBasins in Operation
0.84 0.85 2
Aerator # Nameplate HP
Avg Low SpeedAmps
Avg High Speed
Amps (1)
Months in low setting
Avg Amps Avg KW Avg Operating
HP#1 100 0.00 0 121.2 84.6 113.5#2 100 0.00 0 95.1 66.4 89.0#3 100 0.00 0 99.2 69.3 92.9#4 100 92.66 0 105.8 73.9 99.0#5 100 100.2 0 102.7 71.7 96.1#6 100 84.66 0 94.0 65.6 87.9#7 100 77.47 0 81.6 57.0 76.4#8 100 76.85 0 82.1 57.3 76.8 Avg#9 100 93.71 0 101.1 70.6 94.6 91.8
T t l 883 616 4 826 3Total 883 616.4 826.3(1)�Data�based�on�typical�3�year�24�hr�average�obtained�from�City�of�Boca�Raton�for�2009���2011
Blower # Nameplate HP
Factor(2) Adjusted HP
#1 100 0.09 7.65#2 100 0#3 100 0
(2)�Factor�based�on�one�blower�operating�4�hours�per�day,�3�months�out�of�year
Operating�HP�/�Nameplate�HP Zone�1�Avg Zone�2�Avg Zone�3�Avg0.92 96.3 87.3 91.8
188
6.1.
1 LI
FE-C
YCLE
CO
ST A
NA
LYSI
STh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 0
.5 m
g/L
213
38%
$97,
588
($1,
576,
789)
#VALU
E!11.98
0.07
0.04
70.
025
0.02
20.
0008
320
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
153%
$6,6
68($
107,
737)
#VALU
E!C
ompl
ete
NO
x-9
3-1
7%($
42,7
14)
$690
,161
#VALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
489%
$21,
929
($35
4,32
4)#V
ALU
E!17
.26
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
7614
%$3
4,55
7($
558,
359)
#VALU
E!10
.30
Com
plet
e N
Ox
9116
%$4
1,41
6($
669,
178)
#VALU
E!8.
46C
urre
nt T
reat
men
t - 0
.5 m
g/L
00%
$0$0
154,141
$���������
Par
tial N
itrifi
catio
n -
1.5
mg/
L11
821
%$5
4,17
9($
875,
399)
154,141
$���������
6.76
Com
plet
e N
Ox
145
26%
$66,
534
($1,
075,
026)
154,141
$���������
5.72
Cur
rent
Tre
atm
ent -
0.5
mg/
L26
147
%$1
19,5
17($
1,93
1,11
3)1,
541,
011
$
15
.58
Par
tial N
itrifi
catio
n -
1.5
mg/
L20
937
%$9
5,40
4($
1,54
1,49
5)1,
541,
011
$
19
.99
Com
plet
e N
Ox
143
26%
$65,
235
($1,
054,
043)
1,54
1,01
1$
31.1
8*
Cur
rent
trea
tmen
t ind
icat
es e
nerg
y im
prov
emen
t rea
lized
by
treat
ing
to p
artia
l nitr
ifica
tion
at 0
.5 m
g/L,
whi
ch is
the
plan
ts c
urre
nt le
vel o
f tre
atm
ent
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual
Sav
ings
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
834
538
%$9
7,58
8($
1,57
6,78
9)9,106
$��������������
146,056
$������������
(1,558,926)
$�������
#VALU
E!#V
ALU
E!11
.98
Par
tial N
itrifi
catio
n -
3.0
mg/
L55
854
43%
$6,6
68($
107,
737)
9,106
$��������������
146,056
$������������
(1,558,926)
$�������
#VALU
E!#V
ALU
E!C
ompl
ete
NO
x55
865
2-1
7%($
42,7
14)
$690
,161
9,106
$��������������
146,056
$������������
(1,558,926)
$�������
#VALU
E!#V
ALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
558
297
47%
$119
,517
($1,
931,
113)
8,606
$��������������
138,036
$������������
(1,558,926)
$�������
$2,807,759
1,386,870
$��
13.0
0P
artia
l Nitr
ifica
tion
- 3.
0 m
g/L
558
468
16%
$41,
225
($66
6,09
6)8,606
$��������������
138,036
$������������
(1,558,926)
$�������
$2,807,759
1,386,870
$��
78.2
4C
ompl
ete
NO
x55
856
1-1
%($
1,29
9)$2
0,98
38,606
$��������������
138,036
$������������
(1,558,926)
$�������
$2,807,759
1,386,870
$��
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
Tota
l (C
umul
ativ
e)
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
829
747
%$1
19,5
17($
1,93
1,11
3)(10,091)
$����������
(161,857)
$����������
(1,558,926)
$�������
$3,261,794
1,541,011
$��
15.5
8P
artia
l Nitr
ifica
tion
- 1.5
mg/
L55
835
037
%$9
5,40
4($
1,54
1,49
5)(10,091)
$����������
(161,857)
$����������
(1,558,926)
$�������
$3,261,794
1,541,011
$��
19.9
9C
ompl
ete
NO
x55
841
626
%$6
5,23
5($
1,05
4,04
3)(10,091)
$����������
(161,857)
$����������
(1,558,926)
$�������
$3,261,794
1,541,011
$��
31.1
8
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
4. M
ost O
pen
Val
ve
Blo
wer
Con
trol v
s/
Pre
ssur
e S
etpo
int
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
189
6.1.
2 LI
FE-C
YCLE
CO
ST A
NA
LYSI
S (L
OW
RA
NG
E)Th
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 0
.5 m
g/L
213
38%
$97,
588
($1,
576,
789)
#VALU
E!5.20
0.07
0.04
70.
025
0.02
20.
0008
320
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
153%
$6,6
68($
107,
737)
#VALU
E!C
ompl
ete
NO
x-9
3-1
7%($
42,7
14)
$690
,161
#VALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
489%
$21,
929
($35
4,32
4)#V
ALU
E!13
.45
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
7614
%$3
4,55
7($
558,
359)
#VALU
E!8.
16C
ompl
ete
NO
x91
16%
$41,
416
($66
9,17
8)#V
ALU
E!6.
73C
urre
nt T
reat
men
t - 0
.5 m
g/L
00%
$0$0
60,107
$������������
Par
tial N
itrifi
catio
n -
1.5
mg/
L11
821
%$5
4,17
9($
875,
399)
60,107
$������������
5.28
Com
plet
e N
Ox
145
26%
$66,
534
($1,
075,
026)
60,107
$������������
4.48
Cur
rent
Tre
atm
ent -
0.5
mg/
L26
147
%$1
19,5
17($
1,93
1,11
3)88
9,21
7$
9.
00P
artia
l Nitr
ifica
tion
- 1.
5 m
g/L
209
37%
$95,
404
($1,
541,
495)
889,
217
$
11.3
2C
ompl
ete
NO
x14
326
%$6
5,23
5($
1,05
4,04
3)88
9,21
7$
16
.74
* C
urre
nt tr
eatm
ent i
ndic
ates
ene
rgy
impr
ovem
ent r
ealiz
ed b
y tre
atin
g to
par
tial n
itrifi
catio
n at
0.5
mg/
L, w
hich
is th
e pl
ants
cur
rent
leve
l of t
reat
men
t
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
834
538
%$9
7,58
8($
1,57
6,78
9)9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!5.
20P
artia
l Nitr
ifica
tion
- 3.
0 m
g/L
558
544
3%$6
,668
($10
7,73
7)9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!C
ompl
ete
NO
x55
865
2-1
7%($
42,7
14)
$690
,161
9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
558
297
47%
$119
,517
($1,
931,
113)
8,60
6$��������������
138,03
6$������������
(1,558
,926
)$��������
$2,250,000
829,111
$�����
6.76
Par
tial N
itrifi
catio
n -
3.0
mg/
L55
846
816
%$4
1,22
5($
666,
096)
8,60
6$��������������
138,03
6$������������
(1,558
,926
)$��������
$2,250,000
829,111
$�����
28.3
3C
ompl
ete
NO
x55
856
1-1
%($
129
9)$2
098
3860
6$
13803
6$
(155
892
6)$
$2250000
829111
$
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x55
856
1-1
%($
1,29
9)$2
0,98
38,60
6$��������������
138,03
6$������������
(1,558,926
)$��������
$2,250,000
829,111
$�����
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
829
747
%$1
19,5
17($
1,93
1,11
3)(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$2,610,000
889,217
$�����
Par
tial N
itrifi
catio
n - 1
.5 m
g/L
558
350
37%
$95,
404
($1,
541,
495)
(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$2,610,000
889,217
$�����
11.3
2C
ompl
ete
NO
x55
841
626
%$6
5,23
5($
1,05
4,04
3)(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$2,610,000
889,217
$�����
16.7
4
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
190
6.1.
3 LI
FE-C
YCLE
CO
ST A
NA
LYSI
S (H
IGH
RA
NG
E)Th
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 0
.5 m
g/L
213
38%
$97,
588
($1,
576,
789)
#VALU
E!24
.36
0.07
0.04
70.
025
0.02
20.
0008
320
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
153%
$6,6
68($
107,
737)
#VALU
E!C
ompl
ete
NO
x-9
3-1
7%($
42,7
14)
$690
,161
#VALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
489%
$21,
929
($35
4,32
4)#V
ALU
E!24
.13
Par
tial N
itrifi
catio
n - 3
.0 m
g/L
7614
%$3
4,55
7($
558,
359)
#VALU
E!13
.98
Com
plet
e N
Ox
9116
%$4
1,41
6($
669,
178)
#VALU
E!11
.39
Cur
rent
Tre
atm
ent -
0.5
mg/
L0
0%$0
$029
0,10
7$���������
Par
tial N
itrifi
catio
n -
1.5
mg/
L11
821
%$5
4,17
9($
875,
399)
290,10
7$���������
8.99
Com
plet
e N
Ox
145
26%
$66,
534
($1,
075,
026)
290,10
7$���������
7.57
Cur
rent
Tre
atm
ent -
0.5
mg/
L26
147
%$1
19,5
17($
1,93
1,11
3)2,
519,
217
$
27
.55
Par
tial N
itrifi
catio
n -
1.5
mg/
L20
937
%$9
5,40
4($
1,54
1,49
5)2,
519,
217
$
36
.96
Com
plet
e N
Ox
143
26%
$65,
235
($1,
054,
043)
2,51
9,21
7$
67.3
0*
Cur
rent
trea
tmen
t ind
icat
es e
nerg
y im
prov
emen
t rea
lized
by
treat
ing
to p
artia
l nitr
ifica
tion
at 0
.5 m
g/L,
whi
ch is
the
plan
ts c
urre
nt le
vel o
f tre
atm
ent
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
834
538
%$9
7,58
8($
1,57
6,78
9)9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!24
.36
Par
tial N
itrifi
catio
n -
3.0
mg/
L55
854
43%
$6,6
68($
107,
737)
9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!C
ompl
ete
NO
x55
865
2-1
7%($
42,7
14)
$690
,161
9,10
6$��������������
146,05
6$������������
(1,558
,926
)$��������
#VALU
E!#V
ALU
E!C
urre
nt T
reat
men
t - 0
.5 m
g/L
558
297
47%
$119
,517
($1,
931,
113)
8,60
6$��������������
138,03
6$������������
(1,558
,926
)$��������
$3,650,000
2,229,111
$��
24.3
1P
artia
l Nitr
ifica
tion
- 3.
0 m
g/L
558
468
16%
$41,
225
($66
6,09
6)8,60
6$��������������
138,03
6$������������
(1,558
,926
)$��������
$3,650,000
2,229,111
$��
Com
plet
eN
Ox
558
561
-1%
($1
299)
$20
983
860
6$
13803
6$
(155
892
6)$
$3650000
2229111
$
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x55
856
1-1
%($
1,29
9)$2
0,98
38,60
6$��������������
138,03
6$������������
(1,558,926
)$��������
$3,650,000
2,229,111
$��
Cur
rent
Tre
atm
ent -
0.5
mg/
L55
829
747
%$1
19,5
17($
1,93
1,11
3)(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$4,240,000
2,519,217
$��
Par
tial N
itrifi
catio
n - 1
.5 m
g/L
558
350
37%
$95,
404
($1,
541,
495)
(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$4,240,000
2,519,217
$��
36.9
6C
ompl
ete
NO
x55
841
626
%$6
5,23
5($
1,05
4,04
3)(10,09
1)$�����������
(161
,857
)$�����������
(1,558
,926
)$��������
$4,240,000
2,519,217
$��
67.3
0
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
191
6.2
LIFE
-CYC
LE C
OST
AN
ALY
SIS
SUM
MA
RY
Tech
nolo
gyLe
vel o
f Tre
atm
ent
% E
ff. G
ain
Avg
. Dai
ly
Ener
gy S
avin
gs(k
wH
)
Ann
. Ene
rgy
Cos
t Sav
ings
($
)
Payb
ack
(Low
Es
timat
e)(Y
ears
)
Payb
ack
(Med
ian
Estim
ate)
(Yea
rs)
Payb
ack
(Hig
h Es
timat
e)(Y
ears
)
Cur
rent
Tre
atm
ent -
0.5
mg/
L D
O38
%3,
819
$97,
588
512
24Pa
rt. N
itrifi
catio
n - 3
.0 m
g/L
DO
3%26
1$6
,668
--
-C
ompl
ete
Nitr
ifica
tion
-17%
-1,6
72($
42,7
14)
--
-C
urre
nt T
reat
men
t - 0
.5 m
g/L
DO
9%85
8$2
1,92
913
1724
Part.
Nitr
ifica
tion
- 3.0
mg/
L D
O14
%1,
353
$34,
557
810
14C
ompl
ete
Nitr
ifica
tion
16%
1,62
1$4
1,41
67
811
Cur
rent
Tre
atm
ent -
0.5
mg/
L D
O0%
0$0
--
-
Part.
Nitr
ifica
tion
- 1.5
mg/
L D
O21
%2,
120
$54,
179
57
9C
ompl
ete
Nitr
ifica
tion
26%
2,60
4$6
6,53
44
68
Cur
rent
Tre
atm
ent -
0.5
mg/
L D
O47
%4,
678
$119
,517
916
28Pa
r. N
itrifi
catio
n - 1
.5 m
g/L
DO
37%
3,73
4$9
5,40
411
2037
Com
plet
e N
itrifi
catio
n26
%2,
553
$65,
235
1731
67
MWs
0.16
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.5
mg/
L
192
APPENDIX B-1 – BROWARD CO. N. REGIONAL WWTP PRELIMINARY DESIGN DRAWINGS
193
194
195
196
197
198
APPENDIX B-2 – BROWARD CO. N. REGIONAL WWTP DATA SPREADSHEETS
199
BROWARD COUNTY NORTH REGIONAL WWTP - ENERGY EFFICIENCY ANALYSIS SPREASPREADSHEET TABLE OF CONTENTS
1.1 INFLUENT EFFLUENT SPECIFIER1.2�FLOW�PROJECTION2.0 AERATION CALCULATIONS - GLOBAL PARAMETERS2.1 AERATION CALCULATIONS - DIFFUSERS2.2 AERATION CALCULATIONS - TURBO BLOWERS2.3 AERATION CALCULATIONS - 1.5 MG/L DO CONTROL3.1 SYSTEM DESIGN - SIZE PIPES - TRAIN 13.2 SYSTEM DESIGN - ESTIMATE LOSSES THROUGH PIPES3.3 SYSTEM DESIGN - SYSTEM CURVE3.4 SYSTEM DESIGN - BLOWER DESIGN4.0 - COST ESTIMATE - SUMMARY4.1 - COST ESTIMATE - DEMOLITION4.2 - COST ESTIMATE - BLOWERS4.3 - COST ESTIMATE - DIFFUSERS4.4 - COST ESTIMATE - STRUCTURAL4.5 - COST ESTIMATE - MECHANICAL PIPING4.6 - COST ESTIMATE - INSTRUMENTATION4.7 - COST ESTIMATE - ELECTRICAL5.0 - O&M COSTS5.1 - O&M COSTS - REPLACE AERATORS6.0�LIFE�CYCLE�COST�ANALYSIS�INPUTS6.1.1 LIFE-CYCLE COST ANALYSIS6.1.2 LIFE-CYCLE COST ANALYSIS (LOW RANGE)6.1.3�LIFE�CYCLE�COST�ANALYSIS�(HIGH�RANGE)6.2 LIFE-CYCLE COST ANALYSIS SUMMARY
Eric�Stanley���Thesis���2/19/2012���Pg�1�of�29
200
1.1
INFL
UEN
T EF
FLU
ENT
SPEC
IFIE
RTh
is s
prea
dshe
et s
umm
ariz
es th
e va
lues
gle
aned
from
ava
ilabl
e hi
stor
ical
mon
itorin
g da
ta a
t the
WW
TPV
alue
s fro
m th
is s
prea
dshe
et a
re in
serte
d di
rect
ly in
to S
prea
dshe
ets
2.1
- 2.3
.
2004
- 20
06
Cal
cula
ted
Avg
Avg
INF
FLO
WIN
F C
BO
DIN
F TS
SEF
F C
BO
DEF
F W
AS
V SIN
F TK
NEF
F N
H3
DO
SRT
MG
DLB
SLB
SLB
S.LB
S LB
SLB
S.m
g/L
Day
sYi
eld
Min
Day
14.2
119
9410
522
510
1457
4707
1011
1.0
3.7
0.63
AD
F37
.20
4725
771
891
1599
3453
610
458
3268
MM
AD
F44
.15
7192
712
6168
2643
5256
413
935
5459
Max
Day
56.7
218
0246
7336
8368
1013
1724
1551
684
53
2004
- 20
06 A
djus
ted
to 2
011
- 203
1 A
DF
INF
FLO
WIN
F C
BO
DIN
F TS
SEF
F C
BO
DEF
F W
AS
V SIN
F TK
NEF
F N
H3
MG
DLB
SLB
SLB
S.LB
SLB
SLB
S.M
in D
ay15
.94
2236
1180
057
216
3452
7911
34A
DF
41.7
252
998
8062
417
9338
731
1172
936
65M
MA
DF
49.5
280
665
1414
9529
6458
950
1562
861
22M
ax D
ay63
.61
2021
4382
2813
7638
1477
2617
401
9480
2004
- 20
06 3
Yea
r Ave
rage
- A
djus
ted
to D
esig
n Fl
ow o
f 95
MG
D (a
ssum
es 2
bas
ins
in M
odul
e D
onl
ine)
INF
FLO
WIN
F C
BO
DIN
F TS
SEF
F C
BO
DEF
F W
AS
V SIN
F TK
NEF
F N
H3
MG
DLB
SLB
SLB
S.LB
SLB
SLB
S.M
in D
ay16
.12
2262
1193
557
916
5353
3911
47A
DF
42.2
053
605
8154
818
1439
175
1186
337
07M
MA
DF
50.0
881
589
1431
1629
9859
625
1580
761
92M
ax D
ay64
.33
2044
5883
2238
7725
1494
1817
600
9588
Dol
d, 2
007
201
1.2 FLOW PROJECTION
2011 77.95 83.444192012 78.42013 78.852014 79.32015 79.752016 80.6262017 81.5022018 82.3782019 83.2542020 84.132021 84.3762022 84.6222023 84.8682024 85.1142025 85.362026 85.82027 86.32028 86.82029 87.32030 882031 88
Source: North Broward WWTP 2011 Capacity Analysis Report to FDEP
Flow(MGD)Year
2011-2031 Avg
76
78
80
82
84
86
88
90
2010 2015 2020 2025 2030 2035
Cap
ita
Year
Flow Projection
202
2.0 AERATION CALCULATIONS - GLOBAL PARAMETERSSpreadsheet 2.1 - 2.3 calculates the amount of air and horsepower needed to treat various flowrates and loading rates throughout the plant. 2.0 Aeration Calculations - Global Paramters spreadsheet specifies the global variables input to spreadsheets 2.1 - 2.3
Area�under�Aeration�per�Basin�(ft2)�= 16875 Manual�DO�Control�O2�Concentration 3#�of�basins�online�=� 7.2 Auto�DO�Control�O2�Concentration 1.5Side�water�Depth�(ft)�=� 15.5 MSC�Blower�Efficiency 0.62Diffuser�Submergence�(ft)�=� 14.5 Turbo�Blower�Efficiency 0.72Equation�For�System�Curve 5.87E�10 *�x^2 able�O2�Concentration�at�Max�Day 0.5Number�of�Diffusers�per�Basin�=� 2500 Pre�ECM�Existing�DO�Concentration 1Site�Elevation�(ft�above�MSL)�=� 10Minimum�Mix�Requirements�(scfm/ft2) 0.12Minimum�Flow�per�Diffuser�(scfm) 0.5 Dold�yield,�assume�5�days 0.59 NitrifyingMaximum�Flow�per�Diffuser�(scfm) 3.0General�Temperature 25Beta�(unitless)=� 0.98 Fup 0.13 Biowin�default�for�RawPatm�(psi)�=� 14.7 VSS/TSS 0.85Patm�(mid�depth,�ft�wc/2/2.31�psi,�psi)�=� 3.14Csth�(per�App�D�for�mech�aer,�mg/L)�= 8.24Cs20�(DO�@�20�deg�C,�1�atm,�mg/L)�=� 9.08CstH*�(mg/L)�= 10.00Dens�Air�(lb/cf)�=� 0.0750Mass�Fraction�O2�in�air�=� 0.2315Alpha�=� 0.43Alpha�for�complete�nitrification�=� 0.5Average�of�minimum�SOTE a
Temp. Tau Figure 2.10 & Sanitaire
0 1.65 1.4
10 1.2415 1.1220 125 0.9130 0.8335 0.7740 0.71
y = 4.08E-04x2 - 3.82E-02x + 1.60E+00R² = 9.98E-01
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30 35 40
Tau
(dim
ensi
onle
ss)
Temperature (C)
Tau vs. Temperature
Air Average Minimum Average Minimum Results from trendline in chartFlow SOTE SOTE SOTE SOTE
(SCFM/Unit (%) (%) (%/ft) (%/ft) Constants�for�the�following�formula:�ax4+bx3+cx2+dx+e
0.59 46.83 41.25 2.34 2.06 Avg SOTE 0.05140.88 42.50 37.98 2.13 1.90 Avg SOTE �0.46031.00 41.26 37.37 2.06 1.87 Avg SOTE 1.54051.18 39.89 36.95 1.99 1.85 Avg SOTE �2.34731.47 38.48 35.92 1.92 1.80 Avg SOTE 3.27791.75 38.33 35.90 1.92 1.80 Min SOTE 0.04672.06 37.52 35.39 1.88 1.77 Min SOTE �0.40152.35 37.21 35.35 1.86 1.77 Min SOTE 1.27242.50 37.07 35.20 1.85 1.76 Min SOTE �1.79842.65 36.87 35.18 1.84 1.76 Min SOTE 2.75262.94 36.69 35.01 1.83 1.753.00 36.66 35.00 1.83 1.75
Air Average Minimum Average MinimumFlow SOTE SOTE SOTE SOTE
(SCFM/Unit (%) (%) (%/ft) (%/ft)
0.59 40.58 35.74 2.34 2.060.88 36.83 32.91 2.13 1.901.00 35.75 32.38 2.06 1.871.18 34.56 32.02 1.99 1.851.47 33.34 31.12 1.92 1.801.75 33.21 31.11 1.92 1.802.06 32.51 30.67 1.88 1.772.35 32.24 30.63 1.86 1.772.50 32.12 30.57 1.85 1.762.65 31.95 30.48 1.84 1.762.94 31.79 30.34 1.83 1.753.00 31.77 30.33 1.83 1.75
Submergence = 20.00-ft
Submergence = 17.33-ft
y�=�0.0514x4 � 0.4603x3 +�1.5405x2 � 2.3473x�+�3.2779R²�=�0.9987
y�=�0.0467x4 � 0.4015x3 +�1.2724x2 � 1.7984x�+�2.7526R²�=�0.9944
1.50
1.60
1.70
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50
SOTE�%�/�fo
ot�of�d
iffuser�sub
mergence
SCFM/Diffuser
SOTE�vs.�SCFM/diffuser�Sanitaire�� Silver�Series�II��9"�Membrane�Disc�Diffuser�
Average�SOTE
Min.�SOTE
Poly.�(Average�SOTE)
Poly.�(Min.�SOTE)
203
2.1
AER
ATI
ON
CA
LCU
LATI
ON
S - D
IFFU
SER
SS
prea
dshe
et 2
.1 -
2.3
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
1 A
erat
ion
Cal
cula
tions
- D
iffus
ers
spre
adsh
eet p
redi
cts
the
effic
ienc
y im
prov
emen
t by
upgr
adin
g to
fine
bub
ble
diffu
sers
with
no
othe
r EC
Is.
Ass
umes
mul
ti-st
age
cent
rifug
al b
low
ers
at 6
2% e
ffici
ency
.
Cur
Tre
atA
DF
AD
F +
Nit
Min
Day
Min
Day
AD
F A
DF
MM
AD
FM
MA
DF
MD
FM
DF
Cur
Tre
at
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2004���2006
2.�In
puts
MGD
41.72
41.72
41.72
14.21
16.12
42.20
42.20
50.08
50.08
64.33
64.33
37.20
Num
ber�of�Basins�Online
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
88
6.3
So�=�CBO
Dinf
52,998
52,998
52,998
1,994
2,262
53,605
53,605
81,589
81,589
104,806
104,806(lb
/day)
47,257
S�=�CB
ODeff
1,793
1,793
1,793
510
579
1,814
1,814
2,998
2,998
3,851
3,851(lb
/day)
1,599
Eq.�8�15�(w
here�hilighted),�PxBio�=�
29,822
29,822
27,363
295
334
30,164
27,676
43,811
40,025
43,811
55,915
(lb/day)
26,592
TKN�=�
11,729
11,729
11,729
4,707
5,339
11,863
11,863
15,807
15,807
20,305
20,305
(lb/day)
10,458
NH3�eff�=
�3,665
3,665
174
1,011
1,147
3,707
176
6,192
209
7,955
268(lb
/day)
3,268
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
13
33
33
33
30.5
0.5mg/L
1T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
25Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
0.43
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
aa
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
4,485
4,485
8,271
3,661
4,152
4,536
8,366
4,357
10,795
7,093
13,326
(lb/day)
3,999
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
72,108
72,108
91,995
18,186
20,629
72,934
93,049
102,518
135,770
155,872
165,676(lb
/day)
64,297
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.42
0.31
0.36
0.31
0.31
0.31
0.36
0.31
0.36
0.44
0.52
0.40
SOR�=�
172,953
232,394
254,979
58,611
66,484
235,056
257,900
330,401
376,308
351,395
321,208(lb
/day)
159,682
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
6,918
9,295
10,198
2,344
2,659
9,401
10,315
13,215
15,051
14,055
12,847
6,387
TotalN
umbe
rof
Diffusers=
18000
18000
18000
18000
18000
18000
18000
18000
18000
20000
20000
22050
Total�N
umbe
r�of�Diffusers�=�
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
20,000
20,000
22,050
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.36
1.88
2.08
0.34
0.40
1.90
2.10
2.75
3.13
2.63
2.38
1.33
Diffuser�Flow,�scfm/diffuser�=�
1.36
1.88
2.08
0.34
0.40
1.90
2.10
2.75
3.13
2.63
2.38
1.23
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.10
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
28.33%
27.45%
27.27%
38.28%
37.12%
27.43%
27.24%
26.67%
26.70%
26.77%
26.98%
23.50%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
24421
33860
37404
6124
7164
34277
37865
49542
56363
52511
47609
27,181
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
1119
1610
1808
270
316
1633
1834
2553
3026
2754
2426
hp1269
Dynam
ic�Losses
0.35
0.67
0.82
0.02
0.03
0.69
0.84
1.44
1.86
1.62
1.33
psi
2.02
Wire�to�Air�Eff�=�
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
Unitle
ss0.62
e=100%
*((P1+14.7)/14.7)0.283�1)/�1
��(P2
+14.7)/14.7)0.283�1)/�2)/((P1+14.7)/14.7)�0
.283�1)/�2
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)14580
14580
14580
14580
14580
14580
14580
14580
14580
16200
16200
16386.3
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
204
2.2
AER
ATI
ON
CA
LCU
LATI
ON
S - T
UR
BO
BLO
WER
SS
prea
dshe
et 2
.1 -
2.3
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
2 A
erat
ion
Cal
cula
tions
-Tur
bo B
low
ers
spre
adsh
eet p
redi
cts
effic
ienc
y im
prov
emen
t of f
ine
bubb
le d
iffus
ers
with
turb
o bl
ower
s as
sum
ing
72%
effi
ency
.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
F
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�In
puts
MGD
41.72
41.72
41.72
14.21
16.12
42.20
42.20
50.08
50.08
64.33
64.33
Num
ber�of�Basins�Online
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
88
So�=�CBO
Dinf
52,998
52,998
52,998
1,994
2,262
53,605
53,605
81,589
81,589
104,806
104,806(lb
/day)
S�=�CB
ODeff
1,793
1,793
1,793
510
579
1,814
1,814
2,998
2,998
3,851
3,851(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
29,822
29,822
27,363
295
334
30,164
27,676
43,811
40,025
43,811
55,915
(lb/day)
TKN�=�
11,729
11,729
11,729
4,707
5,339
11,863
11,863
15,807
15,807
20,305
20,305
(lb/day)
NH3�eff�=
�3,665
3,665
174
1,011
1,147
3,707
176
6,192
209
7,955
268(lb
/day)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
13
33
33
33
30.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
4,485
4,485
8,271
3,661
4,152
4,536
8,366
4,357
10,795
7,093
13,326
(lb/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
72,108
72,108
91,995
18,186
20,629
72,934
93,049
102,518
135,770
155,872
165,676(lb
/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.42
0.31
0.36
0.31
0.31
0.31
0.36
0.31
0.36
0.44
0.52
SOR�=�
172,953
232,394
254,979
58,611
66,484
235,056
257,900
330,401
376,308
351,395
321,208(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
6,918
9,295
10,198
2,344
2,659
9,401
10,315
13,215
15,051
14,055
12,847
TotalN
umbe
rof
Diffusers=
18000
18000
18000
18000
18000
18000
18000
18000
18000
20000
20000
Total�N
umbe
r�of�Diffusers�=�
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
20,000
20,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.36
1.88
2.08
0.34
0.40
1.90
2.10
2.75
3.13
2.63
2.38
Diffuser�Flow,�scfm/diffuser�=�
1.36
1.88
2.08
0.34
0.40
1.90
2.10
2.75
3.13
2.63
2.38
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
28.33%
27.45%
27.27%
38.28%
37.12%
27.43%
27.24%
26.67%
26.70%
26.77%
26.98%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
24421
33860
37404
6124
7164
34277
37865
49542
56363
52511
47609
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
964
1386
1556
232
272
1406
1579
2199
2606
2371
2089
hpDynam
ic�Losses
0.35
0.67
0.82
0.02
0.03
0.69
0.84
1.44
1.86
1.62
1.33
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)14580
14580
14580
14580
14580
14580
14580
14580
14580
16200
16200
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
205
2.3
AER
ATI
ON
CA
LCU
LATI
ON
S - 1
.5 M
G/L
DO
CO
NTR
OL
Spr
eads
heet
2.1
-2.3
cal
cula
tes
the
amou
nt o
f air
and
hors
epow
er re
quire
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
3 A
erat
ion
Cal
cula
tions
-1.5
MG
/L D
o C
ontro
l spr
eads
heet
pre
dict
s ef
ficie
ncy
impr
ovem
ent o
f fin
e bu
bble
diff
user
s, tu
rbo
blow
ers,
and
DO
Con
trol
.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
F
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�In
puts
MGD
41.72
41.72
41.72
14.21
16.12
42.20
42.20
50.08
50.08
64.33
64.33
Num
ber�of�Basins�Online
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
88
So�=�CBO
Dinf
52,998
52,998
52,998
1,994
2,262
53,605
53,605
81,589
81,589
104,806
104,806(lb
/day)
S�=�CB
ODeff
1,793
1,793
1,793
510
579
1,814
1,814
2,998
2,998
3,851
3,851(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
29,822
29,822
27,363
295
334
30,164
27,676
43,811
40,025
43,811
55,915
(lb/day)
TKN�=�
11,729
11,729
11,729
4,707
5,339
11,863
11,863
15,807
15,807
20,305
20,305
(lb/day)
NH3�eff�=
�3,665
3,665
174
1,011
1,147
3,707
176
6,192
209
7,955
268(lb
/day)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
11.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
0.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.43
0.43
0.5
0.43
0.43
0.43
0.5
0.43
0.5
0.43
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
4,485
4,485
8,271
3,661
4,152
4,536
8,366
4,357
10,795
7,093
13,326
(lb/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
72,108
72,108
91,995
18,186
20,629
72,934
93,049
102,518
135,770
155,872
165,676(lb
/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.42
0.39
0.45
0.39
0.39
0.39
0.45
0.39
0.45
0.44
0.52
SOR�=�
172,953
184,768
202,725
46,599
52,859
186,884
205,047
262,690
299,189
351,395
321,208(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
6,918
7,390
8,108
1,864
2,114
7,475
8,201
10,507
11,967
14,055
12,847
TotalN
umbe
rof
Diffusers=
18000
18000
18000
18000
18000
18000
18000
18000
18000
20000
20000
Total�N
umbe
r�of�Diffusers�=�
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
20,000
20,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.36
1.46
1.62
0.26
0.30
1.48
1.64
2.15
2.47
2.63
2.38
Diffuser�Flow,�scfm/diffuser�=�
1.36
1.46
1.62
0.26
0.30
1.48
1.64
2.15
2.47
2.63
2.38
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
28.33%
28.06%
27.77%
40.12%
39.16%
28.02%
27.74%
27.20%
26.90%
26.77%
26.98%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
24421
26338
29201
4645
5399
26678
29568
38623
44484
52511
47609
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
964
1046
1173
176
205
1061
1189
1617
1919
2371
2089
hpDynam
ic�Losses
0.35
0.41
0.50
0.01
0.02
0.42
0.51
0.88
1.16
1.62
1.33
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)14580
14580
14580
14580
14580
14580
14580
14580
14580
16200
16200
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
206
3.1
SYST
EM D
ESIG
N -
SIZE
PIP
ES -
TRA
IN 1
This
spr
eads
heet
dem
onst
rate
s th
e si
zing
of t
he p
ropo
sed
aera
tion
proc
ess
air p
ipes
.P
er T
able
5-2
8 - M
etca
lf &
Edd
yFr
om 5
th O
rder
Cur
ve F
itTy
pica
l air
velo
citie
s in
aer
atio
n Fi
gure
4-1
- S
atur
atio
n W
RH
Inle
t =
0.41
head
er p
ipes
Wat
er v
apor
pre
ssur
e (p
sT d
isch
arge�=
175
Fbe
cal
cula
ted
with
the
foll
Pdi
scha
rge
=8.
71ps
igPi
pe D
iaVe
loci
tyV
P =
a*T
5+�b*
T4+�c*T3
+V
p ac
t6.
7169
0069
8In
fpm
Whe
re:
VP
std
0.33
9020
461
- 312
00 -
1800
a =
2.27
E-1
1A
irflo
ws
4 - 1
018
00 -
3000
b =
-2.5
E-1
0A
vera
ge A
nnua
l Air
Flow
:26
,678
scfm
2263
9ac
fm12
- 24
2700
- 40
00c
=5.
08E
-07
Max
imum
Mon
th A
ir Fl
ow:
44,4
84sc
fm37
750
acfm
30 -
6038
00 -
6500
d =
7.42
E-0
6M
axim
um D
ay A
ir Fl
ow:
47,6
09sc
fm40
402
acfm
e =
0.00
1485
f =0.
0162
74
Tota
l Air
Flow
:37
,750
scfm
40,4
02sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
48in
Act
ual V
eloc
ity:
3,00
4fp
m3,
215
fpm
Num
ber o
f Par
alle
l Aer
atio
n Tr
ains
:2
ea2
eaA
ir Fl
ow P
er T
reat
men
t Tra
in:
18,8
75sc
fm20
,201
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:36
inA
ctua
l Vel
ocity
:2,
670
fpm
2,85
8fp
m
Spl
it 1
2ea
2ea
Max
. Mon
thP
eak
Day
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
Spl
it 1
2ea
2ea
Air
Flow
To
Zone
s 1,
2, 3
:9,
437
scfm
10,1
00sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
30in
Act
ual V
eloc
ity:
1,92
3fp
m2,
058
fpm
Spl
it 2
0.67
ea0.
67ea
Air
Flow
to Z
ones
2, 3
6,29
2sc
fm6,
734
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:24
inA
ctua
l Vel
ocity
:2,
003
fpm
2,14
3fp
m
Spl
it 3
0.33
0.33
Air
Flow
To
Trai
n 3
:3,
146
scfm
3,36
7sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
20in
Act
ual V
eloc
ity:
1,44
2fp
m1,
543
fpm
Spl
it to
hal
f bas
in
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
207
3.2
SYST
EM D
ESIG
N -
ESTI
MA
TE L
OSS
ES T
HR
OU
GH
PIP
ESFr
om 5
th O
rder
Cur
ve F
it of
Ste
phen
son/
Nix
on,
This
spr
eads
heet
dem
onst
rate
s th
e ca
lcul
atio
n of
wor
st-c
ase
head
loss
thro
ugh
the
prop
osed
aer
atio
n pi
ping
sys
tem
Figu
re 4
-1 -
Sat
urat
ion
Wat
er V
apor
Pre
ssur
e,W
ater
vap
or p
ress
ure
(psi
) vs
tem
pera
ture
(°F)
can
P
inle
t =
14.5
3ps
iabe
cal
cula
ted
with
the
follo
win
g fo
rmul
aT
inle
t =
101
fQ
proc
ess
4760
9sc
fmV
P =
a*T
5+�b*
T4+�c*T3
+�d*
T2+�e*T�+�f
RH
Inle
t =
0.41
Qpr
oces
s52
178.
59ic
fmW
here
:T d
isch
arge�=
175
FQ
proc
ess
3975
4.7
acfm
a =
2.27
E-1
1P d
isch
arge
=9.
05ps
igb
=-2
.5E
-10
��=
0.00
022 5
ft2/s
c =
5.08
E-0
7�
=0.
0000
5in
ches
for s
t. st
eel
d =
7.42
E-0
6�
act=
0.10
0669
7lb
/scf
e =
0.00
1485
Vp
act
6.71
6900
7f =
0.01
6274
VP
std
0.33
9020
5V
p in
let
0.97
8097
1
Des
crip
tion
Cum
mul
ativ
e Lo
ssh L
(inH
2O)
h L(p
si)
(1)
Inle
t Filt
er L
oss
30.
1082
3(2
)In
let S
ilenc
er L
oss
1.5
0.05
411
(3)
Loss
acr
oss
diffu
ser
120.
4329
Tota
l Blo
wer
Pip
ing
Inle
t Los
ses
=0.
16ps
i
Min
or L
osse
s (e
st.)
Tota
l Los
ses
Cum
mul
ativ
e Lo
ssD
escr
iptio
nD
iam
(in)
Q (s
cfm
)Q
(icf
m)
Q (a
cfm
)D
iam
(in)
Vel (
fpm
)Le
ngth
(ft)
Re
�/D
f cal
chi
(inH
2O)
h L(in
H2O
)�
Kh L
(inH
2O)
h L(in
H2O
)h L
(psi
)h L
(inH
2O)
h L(p
si)
(1)
16" B
low
er O
utle
t16
6801
.313
044.
6556
79.2
416
4067
.458
135.
22E
+06
0.00
0003
0.00
91.
3865
120.
1239
655.
27.
2098
647.
3338
290.
2645
687.
3338
290.
2645
68(2
)48
" Air
Pip
ing
4847
609.
152
178.
5939
754.
748
3163
.579
777.
22E
+07
0.00
0001
0.00
70.
8387
540.
1079
453.
93.
2711
423.
3790
870.
1219
0110
.712
920.
3864
69(3
)36
" Air
Pip
ing
3623
804.
626
089.
2919
877.
436
2812
.07
192
1.20
E+0
80.
0000
010.
007
0.66
2719
0.27
8922
1.4
0.92
7807
1.20
6729
0.04
3533
11.9
1964
0.43
0002
(4)
30" A
ir P
ipin
g30
1190
2.3
1739
2.86
9938
.68
3020
24.6
919
57.
31E
+07
0.00
0002
0.00
70.
3435
540.
1841
670.
80.
2748
430.
4590
10.
0165
5912
.378
650.
4465
6(5
)24
" Air
Pip
ing
2479
34.8
586
96.4
3166
25.7
824
2109
.052
682.
12E
+07
0.00
0002
0.00
80.
3727
80.
0977
320.
80.
2982
240.
3959
560.
0142
8412
.774
610.
4608
45(6
)20
" Air
Pip
ing
2039
67.4
386
96.4
3133
12.8
920
1518
.518
681.
27E
+07
0.00
0003
0.00
80.
1932
490.
0645
826.
11.
1788
191.
2434
0.04
4856
14.0
1801
0.50
57(7
)12
" Air
Pip
ing/
Diff
. Hea
d12
1983
.71
4348
.215
1656
.45
1221
09.0
5210
01.
56E
+07
0.00
0004
0.00
80.
3727
80.
3063
560.
60.
2236
680.
5300
240.
0191
2114
.548
030.
5248
21(8
)Lo
ss T
hrou
gh D
iffus
er/O
rific
e15
150.
5411
2629
.548
031.
0659
46(9
)D
iffus
er F
oulin
g Lo
ss14
140.
5050
5143
.548
031.
5709
97
Aer
atio
n S
yste
m L
osse
s
Blo
wer
Pip
ing
Inle
t Los
ses
��
��� ��
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���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
(9)
use
oug
oss
050
505
35
803
509
9
Tota
l Blo
wer
Pip
ing
Dis
char
ge L
osse
s =
1.57
psi
Cel
l MS
wam
ee J
ain
Stat
ic P
ress
ure
= 7.
14ps
iC
ell N
Pre
ssur
e V
Cel
l OD
arcy
Wei
sbac
hB
low
er D
isch
arge
Pre
ssur
e R
equi
red
=8.
71ps
i
(1)
16" B
low
er O
utle
t1
Che
ck V
alve
, 1 B
FV, 1
4' x
16"
Exp
.(2
)36
" Air
Pip
ing
1 te
e, 4
thru
tees
(3)
30" A
ir P
ipin
g1
thru
tee
(4)
24" A
ir P
ipin
g1
thru
tee,
1 9
0 be
nd, c
ontra
ctio
n(5
)18
" Air
Pip
ing
cont
ract
ion,
1 th
ru te
e(6
)14
" Air
Pip
ing
1 co
ntra
ctio
n, 2
tees
, ven
turi
met
er, m
odul
atin
g bu
tterfl
y va
lve
(7)
12" A
ir P
ipin
g/D
iff. H
ead
2 90
ben
ds(8
)6"
Air
Pip
ing
(9)
Loss
Thr
ough
Diff
user
Rec
omm
ende
d pe
r San
itaire
(10)
Diff
user
Los
s w
/ Age
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
208
3.3 SYSTEM DESIGN - SYSTEM CURVEThis spreadsheet displays the system curve of the aeration blower piping system. The data is poltted on graphs on the following spreadsheets.
SCFM PSI0 7.14
1000 7.142000 7.153000 7.154000 7.155000 7.166000 7.177000 7.188000 7.199000 7.20
10000 7.2111000 7.2312000 7.2413000 7.2614000 7.2815000 7.3016000 7.3217000 7.3418000 7.3719000 7.3920000 7.4221000 7.4522000 7.4823000 7.5124000 7.5425000 7.5826000 7.6127000 7.6528000 7.6929000 7.7330000 7.7731000 7.8132000 7.8533000 7.9034000 7.9435000 7 99
y�=�6.93E�10x2 +�7.14E+00R²�=�1.00E+00
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0 20000 40000 60000 80000
Series1
Poly.�(Series1)
35000 7.9936000 8.0437000 8.0938000 8.1439000 8.2040000 8.2541000 8.3142000 8.3743000 8.4244000 8.4845000 8.5546000 8.6147000 8.6748000 8.7449000 8.8150000 8.8851000 8.9552000 9.0253000 9.0954000 9.1655000 9.2456000 9.3257000 9.3958000 9.4759000 9.5660000 9.6461000 9.7262000 9.8163000 9.8964000 9.9865000 10.0766000 10.1667000 10.25
209
3.4 SYSTEM DESIGN - BLOWER DESIGNThis spreadsheet details the multiple temperature, pressure, and flow related conditions that are taken into account to correctly size the blowers
Historical Weather Data for West Palm BeachData Source Parameter Value
ASHRAE Extreme (1%) Conditions for WPB
Design Temperature (Wet Bulb) (°F): 80
NOAA Records for West Palm Beach
Maximum Temperature (°F): 101
Resulting Relative Humidity*: 41%
Blower Inlet and Discharge Pressures From 5th Order Curve Fit of Stephenson/Nixon, Ambient Barometric Pressure (psia) 14.696 Figure 4-1 - Saturation Water Vapor Pressure,Blower Inlet Pressure (psia) 14.53 Water vapor pressure (psi) vs temperature (°F) can System Design Pressure Loss (psig): 8.71 be calculated with the following formula:Estimated Discharge Pressure (psia): 23.41 VP = a*T5 +�b*T4 +�c*T3�+�d*T2�+�e*T�+�f
Where:Correct Blower Florate Design Point for Extreme Hot Weather Condition a = 2.27E-11 32°F � T � 140°FParameter Std. Cond. Design b = -2.5E-10Inlet Temperature (°F): 68.0 101.0 c = 5.08E-07Absolute Inlet Temperature (°R): 528 561 d = 7.42E-06Relative Humidity: 36% 41% e = 0.001485Vapor Pressure (psi): 0.3390 0.9781 --------------> f = 0.016274Barometric Pressure (psi): 14.70 14.53Density Correction Factor (ICFM/SCFM): 1.00 1.10 -------------->Maximum Day Air Flow (CFM): 47,609 52,166
Correct Blower Pressure Design Point for Extreme Hot Weather Conditionk-1/k 0.283 0.283Approximate Site Discharge Pressure (psig): 8.71Equivalent Air Pressure (EAP) (psig): 9.64 -------------->
Size Blowers Additional InformationMinimum Mixing Air Flow (SCFM): 14,580Average Annual Air Flow (SCFM): 26,678 29,231 icfmMaximum Month Air Flow (SCFM): 38,623 42,320 icfmMaximum Day Air Flow (SCFM): (no nitrification) 52,511 57,538 icfmConversion Factor (ICFM/SCFM): 1.10Number of Blowers: 8
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S
A
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DS
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PTTPEAP
Number of Blowers: 8Ratio of Large To Small 1.5Small Blower Capacity (ICFM): (2 x) 5,000 4,563 SCFM 47457.4554Large Blower Capacity (ICFM): (6 x) 7,000 6,389 SCFMFirm Blower Capacity (ICFM): 45,000Is Max. Month Requirement met w/ Firm Capacity? YesRequired Blower Turn Down to Meet Minimum Flow: 91.7%Site Barometric Pressure (psia): 14.70Small Blower Rating Point (SCFM) 5,000 @ 9.64 psig 200 HP Large Blower Rating Point (SCFM) 7,000 @ 9.64 psig 300 HP
=IF(C38=2,ROUND(D36/2.5,-2),IF(C38=3,ROUND(D36/3.5,-2),IF(C38=4,ROUND(D36/5.5,-2),IF(C38=5,ROUND(D36/7,-2),0)))
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S
A
VPRHPVPRHP
TTSCFMICFM
**
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11
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PTTPEAP
210
4.0 - COST ESTIMATE - SUMMARYThis spreadsheet summarizes the results of the capital cost estimate in spreadsheets 8.1 - 8.7
Item ECM�No.�1 ECM�No.�2 ECM�No.�3 Comments/SourceDemolition $41,132 $41,132 $41,132 Spreadsheet�8.1Blowers $1,070,000 $1,497,500 $1,497,500 Spreadsheet�8.2Diffusers $810,000 $810,000 $810,000 Spreadsheet�8.3Structural���Blower�Building $152,733 $152,733 $152,733 Spreadsheet�8.4Mechanical���Piping $1,367,733 $1,367,733 $1,367,733 Spreadsheet�8.5Instrumentation $138,000 $138,000 $784,500 Spreadsheet�8.6Electrical $577,021 $577,021 $639,047 Spreadsheet�8.7
SubTotal�1 $4,156,619 $4,584,119 $5,292,646
Contractor�OH&P $623,493 $687,618 $793,897 15%���Based�on�Prevailing�RatesMobilization/Demobilization $207,831 $229,206 $264,632 5%���Based�on�prevailing�rates
Subtotal�2 $4,987,943 $5,500,943 $6,351,175
Performance�Bond $49,879 $55,009 $63,512 1%Insurance $24,940 $27,505 $31,756 0.5%���Higher�end�of�01�31�13.30Permits $49,879 $55,009 $63,512 1%���Mid�range�"rule�of�thumb",�01�41�26.50
Subtotal�3 $5,112,642 $5,638,467 $6,509,954
Contingency $511,264 $563,847 $650,995 10%���01�21�16.50���Preliminary�Working�Drawing�StageEngineering�Fee�(design�and�construction�administration�based�on�subtotal�1) $623,493 $687,618 $793,897 15%���Based�on�???
Grand�Total $6,247,399 $6,889,931 $7,954,846AACE�Class�4�Low�Range�(�20%) $5,000,000 $5,510,000 $6,360,000AACE�Class�4�Hi�Range�(+30%) $8,120,000 $8,960,000 $10,340,000
211
4.1
- CO
ST E
STIM
ATE
- D
EMO
LITI
ON
WPB
�City
SOU
RC
ED
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal U
nit C
ost
TOTA
LEC
I No.
Mat
Inde
x0.96
4DEM
OLITION
WPB
�City
Kelly�Tractor�Quo
teC
RA
NE
RE
NTA
L - 4
0 TO
N C
AP
AC
ITY
2M
O$1
0,00
0.00
$20,
000
1La
bor I
ndex
MEC
HANICAL�AER
ATO
R0.69
9Re
move�Mech�Aerator
24EA
$500
.00
$349
.50
$8,3
881
26�05�05
.25�10
70Dem
olish�10
0�HP�Motor�and
�electrical
24EA
$218
.00
$152
.38
$3,6
571
Aeration�ba
sin�cond
uit�o
n�ba
sins�and
�cable�f�M
CCs
26�05�05
.10�01
0 0Dem
olish�RG
S�Co
nduit,�1/2"���1
"20
00LF
$1.62
$1.13
$2,2
651
26�05�05
.10�01
2 0Dem
olish�RG
S�Co
nduit,�1�1/4"���2
"20
00LF
$1.96
$1.37
$2,7
401
26�05�05
.10�03
0 0Dem
olish�armored
�cable,�2�#�12
4000
LF$0
.65
$0.45
$1,8
171
26�05�05
.10�02
9 0Dem
olish�armored
�cable,�3�#�14
4000
LF$0
.69
$0.48
$1,9
291
26�05�05
.10�18
7 0Dem
olish�cable,�#6�GND
4000
LF$0
.12
$0.08
$336
1Sum
ECM�No.�1
$41,13
2EC
M�No.�2
$41,13
2EC
M�No.�3
$41,13
2
212
4.2
- CO
ST E
STIM
ATE
- B
LOW
ERS
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal
TOTA
LEC
I No.
BLOWER
S(6)�3
00�HP�Bo
wers
6EA
$159
,000
$39,750
$198
,750
$1,1
92,5
002
(2)�2
00�HP�Blow
er2EA
$122
,000
$30,500
$152
,500
$305
,000
2
Total
$1,497
,50 0
COMPA
RABLE�MULTI�S
TAGE�CE
NTR
IFUGAL�CO
ST(6)�3
00�HP�Blow
ers
6EA
$110
,000
$27,500
$137
,500
$825
,000
1(2)�2
00�HP�Blow
ers
2EA
$98,000
$24,500
$122
,500
$245
,000
1
Total
$1,070
,000
Sum
ECM�No.�1
$1,070
,000
ECM�No.�2
$1,497
,500
ECM�No.�3
$1,497
,500
Blow
er�Cost�D
ata
HP
Bud
get $
Sou
rce
Ave
rage
HP
Bud
get $
Sou
rce
Ave
rage
50$5
6,00
0E
PA
250
$180
,000
EP
A50
$102
,000
EP
A25
0$1
51,0
00R
ohrb
ach e
75$7
5,00
0E
PA
$75,
000
250
$165
,000
Roh
rbac
he10
0$1
15,0
00E
PA
250
$168
,000
Roh
rbac
he10
0$9
3,00
0R
ohrb
ache
r, et
. al
250
$188
,000
Roh
rbac
he15
0$1
20,0
00E
PA
300
$175
,000
EP
A15
0$1
34,0
00R
ohrb
ache
r, et
. al
300
$142
,000
EP
A20
0$1
20,0
00E
PA
300
$119
,000
Roh
rbac
h e20
0$1
60,0
00E
PA
300
$119
,000
Roh
rbac
he20
0$8
6,00
0R
ohrb
ache
r, et
. al
300
$143
,000
Roh
rbac
he20
0$9
0,00
0R
ohrb
ache
r, et
. al
300
$156
,000
Roh
rbac
he20
0$9
3,00
0R
ohrb
ache
r, et
. al
300
$208
,000
Roh
rbac
he20
0$1
24,0
00R
ohrb
ache
r, et
. al
300
$209
,000
Roh
rbac
he20
0$1
28,0
00R
ohrb
ache
r, et
. al
400
$275
,000
EP
A20
0$1
76,0
00R
ohrb
ache
r, et
. al
400
$132
,000
Roh
rbac
h e40
0$1
98,0
00R
ohrb
ache
500
$325
,000
EP
A$3
25,0
00
MULTI_STAGE�CE
NTR
IFUGAL�CO
STS
HP
Bud
get $
Sour
ceA
vera
ge20
0$9
8,000H&S
$98,000
250
$90,000H&S
$90,000
300
$153
,000
H&S
300
$72,000H&S
300
$104
,000
H&S
350
$110
,000
H&S
$110
,000
400
$135
,000
H&S
400
$88,000H&S
500
$245
,000
H&S
500
$170
,000
H&S
500
$190
,000
H&S
$110
,000
$112
,000
$202
,000
$170
,000
$104
,000
$127
,000
$159
,000
$122
,000
$202
,000
$79,
000
213
4.3
- CO
ST E
STIM
ATE
- D
IFFU
SER
S
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lFa
ctor
Tota
l Uni
tTo
tal
DIFFU
SERS
Equipm
ent
1LS
6000
001.35
8100
0081
0000
Aqu
arius�qu
ote
ECM�No.�1
$810
,000
ECM�No.�2
$810
,000
ECM�No.�3
$810
,000
214
4.1
- CO
ST E
STIM
ATE
- D
EMO
LITI
ON
WPB
�City
SOU
RC
ED
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal U
nit C
ost
TOTA
LEC
I No.
Mat
Inde
x0.96
4DEM
OLITION
WPB
�City
Kelly�Tractor�Quo
teC
RA
NE
RE
NTA
L - 4
0 TO
N C
AP
AC
ITY
2M
O$1
0,00
0.00
$20,
000
1La
bor I
ndex
MEC
HANICAL�AER
ATO
R0.69
9Re
move�Mech�Aerator
24EA
$500
.00
$349
.50
$8,3
881
26�05�05
.25�10
70Dem
olish�10
0�HP�Motor�and
�electrical
24EA
$218
.00
$152
.38
$3,6
571
Aeration�ba
sin�cond
uit�o
n�ba
sins�and
�cable�f�M
CCs
26�05�05
.10�01
0 0Dem
olish�RG
S�Co
nduit,�1/2"���1
"20
00LF
$1.62
$1.13
$2,2
651
26�05�05
.10�01
2 0Dem
olish�RG
S�Co
nduit,�1�1/4"���2
"20
00LF
$1.96
$1.37
$2,7
401
26�05�05
.10�03
0 0Dem
olish�armored
�cable,�2�#�12
4000
LF$0
.65
$0.45
$1,8
171
26�05�05
.10�02
9 0Dem
olish�armored
�cable,�3�#�14
4000
LF$0
.69
$0.48
$1,9
291
26�05�05
.10�18
7 0Dem
olish�cable,�#6�GND
4000
LF$0
.12
$0.08
$336
1Sum
ECM�No.�1
$41,13
2EC
M�No.�2
$41,13
2EC
M�No.�3
$41,13
2
215
4.2
- CO
ST E
STIM
ATE
- B
LOW
ERS
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal
TOTA
LEC
I No.
BLOWER
S(6)�3
00�HP�Bo
wers
6EA
$159
,000
$39,750
$198
,750
$1,1
92,5
002
(2)�2
00�HP�Blow
er2EA
$122
,000
$30,500
$152
,500
$305
,000
2
Total
$1,497
,50 0
COMPA
RABLE�MULTI�S
TAGE�CE
NTR
IFUGAL�CO
ST(6)�3
00�HP�Blow
ers
6EA
$110
,000
$27,500
$137
,500
$825
,000
1(2)�2
00�HP�Blow
ers
2EA
$98,000
$24,500
$122
,500
$245
,000
1
Total
$1,070
,000
Sum
ECM�No.�1
$1,070
,000
ECM�No.�2
$1,497
,500
ECM�No.�3
$1,497
,500
Blow
er�Cost�D
ata
HP
Bud
get $
Sou
rce
Ave
rage
HP
Bud
get $
Sou
rce
Ave
rage
50$5
6,00
0E
PA
250
$180
,000
EP
A50
$102
,000
EP
A25
0$1
51,0
00R
ohrb
ach e
75$7
5,00
0E
PA
$75,
000
250
$165
,000
Roh
rbac
he10
0$1
15,0
00E
PA
250
$168
,000
Roh
rbac
he10
0$9
3,00
0R
ohrb
ache
r, et
. al
250
$188
,000
Roh
rbac
he15
0$1
20,0
00E
PA
300
$175
,000
EP
A15
0$1
34,0
00R
ohrb
ache
r, et
. al
300
$142
,000
EP
A20
0$1
20,0
00E
PA
300
$119
,000
Roh
rbac
h e20
0$1
60,0
00E
PA
300
$119
,000
Roh
rbac
he20
0$8
6,00
0R
ohrb
ache
r, et
. al
300
$143
,000
Roh
rbac
he20
0$9
0,00
0R
ohrb
ache
r, et
. al
300
$156
,000
Roh
rbac
he20
0$9
3,00
0R
ohrb
ache
r, et
. al
300
$208
,000
Roh
rbac
he20
0$1
24,0
00R
ohrb
ache
r, et
. al
300
$209
,000
Roh
rbac
he20
0$1
28,0
00R
ohrb
ache
r, et
. al
400
$275
,000
EP
A20
0$1
76,0
00R
ohrb
ache
r, et
. al
400
$132
,000
Roh
rbac
h e40
0$1
98,0
00R
ohrb
ache
500
$325
,000
EP
A$3
25,0
00
MULTI_STAGE�CE
NTR
IFUGAL�CO
STS
HP
Bud
get $
Sour
ceA
vera
ge20
0$9
8,000H&S
$98,000
250
$90,000H&S
$90,000
300
$153
,000
H&S
300
$72,000H&S
300
$104
,000
H&S
350
$110
,000
H&S
$110
,000
400
$135
,000
H&S
400
$88,000H&S
500
$245
,000
H&S
500
$170
,000
H&S
500
$190
,000
H&S
$110
,000
$112
,000
$202
,000
$170
,000
$104
,000
$127
,000
$159
,000
$122
,000
$202
,000
$79,
000
216
4.3
- CO
ST E
STIM
ATE
- D
IFFU
SER
S
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lFa
ctor
Tota
l Uni
tTo
tal
DIFFU
SERS
Equipm
ent
1LS
6000
001.35
8100
0081
0000
Aqu
arius�qu
ote
ECM�No.�1
$810
,000
ECM�No.�2
$810
,000
ECM�No.�3
$810
,000
217
4.4
- CO
ST E
STIM
ATE
- ST
RU
CTU
RA
LWPB
�City
WPB
�City
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal U
nit C
osTO
TAL
ECI N
o.M
at In
dex
Labo
r Ind
exBLOWER
�BUILDING�CONSTRU
CT0.964
0.699
03�41�33
.60�22
00Precast�T
ees,�Dou
ble�Tees,�R
oof�M
embe
rs,�Std.�
Weight,�12"�x�8'�w
ide,�30'�span
20EA
$1,575
$138
$86
$1,700
$34,
005
103
�30�53
.40�08
2016
"�x�16
",�Avg.�R
einforcing
21CY
$455
$610
$60
$925
$19,
425
103
�30�53
.40�39
40Footings,�strip,�24"�x�12",�reinforced
21CY
$133
$86
$1$1
88$3
,958
103
�30�52
.40�40
50Foun
datio
n�mat,�over�20
�C.Y.
93CY
$197
$106
$1$2
65$2
4,61
21
04�22�10
.28�03
00Co
ncrete�Block,�H
igh�Sten
gth,�350
0�psi,�8"�th
ick
3540
SF$3
$4$6
$21,
324
103
�30�53
.40�35
70Equipm
ent�P
ads,�6'�x�6'�x�8"�Thick
10EA
$157
$129
$2$2
43$2
,433
103
�30�53
.40�35
50Equipm
ent�P
ads,�4'�x�4'�x�8"�Thick
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$67
$61
$1$1
08$1
,077
107
�26�10
.10�07
00Po
yethylen
e�Va
por�Ba
rrier,�Stand
ard,�.004
"�Thick
46100�SF
$3$8
$9$4
011
31�23�16
.16�60
70Structura l�Excavation�for�Minor�Structures,�Sand,�3/4�
CY�Bucket
440CY
$6$6
$9$4
,173
131
�23�23
.13�19
00Dozer�Backfill,�bulk
220CY
$0$1
$2$3
371
31�23�23
.13�22
00Co
mpact�Backfill,�12"�lifts
440CY
$1$2
$3$1
,100
108
�11�63
.23
Storm�Doo
r,�Clear�Ano
dic�Co
ating,�7'0"�x�3'�wide
8EA
$266
$48
$290
$2,3
211
08�33�23
.10�01
00Ro
lling�Service�Doo
r,�10'�x�10'�high
2EA
$1,675
$490
$1,957
$3,9
141
23�37�23
.10�11
00HVA
C�Louvers,�Stand
ard�8"�x�5"
700EA
$31
$15
$40
$28,
307
109
�24�23
.40�10
00Exterior�Stucco,�w/�bo
nding�agen
t39
4.0SY
$4$7
$1$9
$3,4
151
09�91�13
.60�16
00Paint�S
tucco,�rou
gh,�oil�base,�paint�2�coats,�spray
3540
SF$0
$0$0
$889
109
�91�23
.72�28
80Paint�C
MU�Interior,�paint�2�coats,�spray
3540
SF$0
$0$0
$1,0
411
Sum
ECM�No.�1
$152,733
218
4.4
- CO
ST E
STIM
ATE
- ST
RU
CTU
RA
LWPB
�City
WPB
�City
DIV
ISIO
N N
OD
ESC
RIP
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NQ
UA
NTI
TYU
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Mat
eria
lLa
bor
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pTo
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nit C
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ECI N
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exBLOWER
�BUILDING�CONSTRU
CT0.964
0.699
03�41�33
.60�22
00Precast�T
ees,�Dou
ble�Tees,�R
oof�M
embe
rs,�Std.�
Weight,�12"�x�8'�w
ide,�30'�span
20EA
$1,575
$138
$86
$1,700
$34,
005
103
�30�53
.40�08
2016
"�x�16
",�Avg.�R
einforcing
21CY
$455
$610
$60
$925
$19,
425
103
�30�53
.40�39
40Footings,�strip,�24"�x�12",�reinforced
21CY
$133
$86
$1$1
88$3
,958
103
�30�52
.40�40
50Foun
datio
n�mat,�over�20
�C.Y.
93CY
$197
$106
$1$2
65$2
4,61
21
04�22�10
.28�03
00Co
ncrete�Block,�H
igh�Sten
gth,�350
0�psi,�8"�th
ick
3540
SF$3
$4$6
$21,
324
103
�30�53
.40�35
70Equipm
ent�P
ads,�6'�x�6'�x�8"�Thick
10EA
$157
$129
$2$2
43$2
,433
103
�30�53
.40�35
50Equipm
ent�P
ads,�4'�x�4'�x�8"�Thick
10EA
$67
$61
$1$1
08$1
,077
107
�26�10
.10�07
00Po
yethylen
e�Va
por�Ba
rrier,�Stand
ard,�.004
"�Thick
46100�SF
$3$8
$9$4
011
31�23�16
.16�60
70Structura l�Excavation�for�Minor�Structures,�Sand,�3/4�
CY�Bucket
440CY
$6$6
$9$4
,173
131
�23�23
.13�19
00Dozer�Backfill,�bulk
220CY
$0$1
$2$3
371
31�23�23
.13�22
00Co
mpact�Backfill,�12"�lifts
440CY
$1$2
$3$1
,100
108
�11�63
.23
Storm�Doo
r,�Clear�Ano
dic�Co
ating,�7'0"�x�3'�wide
8EA
$266
$48
$290
$2,3
211
08�33�23
.10�01
00Ro
lling�Service�Doo
r,�10'�x�10'�high
2EA
$1,675
$490
$1,957
$3,9
141
23�37�23
.10�11
00HVA
C�Louvers,�Stand
ard�8"�x�5"
700EA
$31
$15
$40
$28,
307
109
�24�23
.40�10
00Exterior�Stucco,�w/�bo
nding�agen
t39
4.0SY
$4$7
$1$9
$3,4
151
09�91�13
.60�16
00Paint�S
tucco,�rou
gh,�oil�base,�paint�2�coats,�spray
3540
SF$0
$0$0
$889
109
�91�23
.72�28
80Paint�C
MU�Interior,�paint�2�coats,�spray
3540
SF$0
$0$0
$1,0
411
Sum
ECM�No.�1
$152,733
219
4.5
- CO
ST E
STIM
ATE
- M
ECH
AN
ICA
L PI
PIN
G�NEED�RS�MEA
NS�QUOTES
DIV
ISIO
N N
OD
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RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal
TOTA
LEC
I No.
2/08
�Felker�Bro12
"�30
4L�SS
1800
FT10
025
125
$225
,000
12/08
�Felker�Bro20
"�30
4L�SS
327FT
200
5025
0$8
1,75
01
2/08
�Felker�Bro24
"�30
4L�SS
272FT
310
77.5
387.5
$105
,400
12/08
�Felker�Bro30
"�30
4L�SS
653FT
400
100
500
$326
,500
12/08
�Felker�Bro36
"�30
4L�SS
277FT
500
125
625
$173
,125
12/08
�Felker�Bro48
"�30
4L�SS
104FT
600
150
750
$78,00
01
30"�Elbo
w2EA
4500
1125
5625
$11,25
01
30"�x�20
"�Tee
11EA
5000
1250
6250
$68,75
01
36"�x�48
"�Tee
1EA
7500
1875
9375
$9,375
136
"�Tee
2EA
7000
1750
8750
$17,50
01
20"�x�12
"�Cross
4EA
4000
1000
5000
$20,00
01
2/08�Felker�Bro24"�x�12"�Cross
4EA
5000
1250
6250
$25,00
01
2/08
�Felker�Bro20
"�x�12
"�Tee
4EA
2500
625
3125
$12,50
01
12"�Tee
24EA
400
100
500
$12,00
01
12"�90
�Deg�Ben
d48
EA50
012
562
5$3
0,00
01
30"�Exp.�Cou
p2EA
1500
375
1875
$3,750
124
"�Exp.�Cou
p6EA
1000
250
1250
$7,500
1Quaote�f/�Vict
12"�Dep
endo
Lok
24EA
950
237.5
1187
.5$2
8,50
01
22�05�29
.10�017H
eavy�Duty�Wall�Sup
208EA
298
14.3
312.3
$64,95
81
12'�Tall���Galv�Steel�Su
7EA
2500
625
3125
$21,87
51
8'�Tall���304
�SS�Elevat
72EA
500
125
625
$45,00
01
Sum
ECM�No.�1
#########
Adjusted�material�cost�for�carbo
n�over�304
�SS�steel�price,�~5:1.�
ECM�No.�2
#########
(f/�MEPS.com�ta
bles).��Assum
ing�supp
ort�is�50
�lb,�M
ay�201
0�$8
28�per
ECM�No.�3
#########
�ton�steel�*50
/200
0�=�$2
0.7�for�material�x�1.5�factor�=�$31
�for�material
$174
��$31
�+�$31
*5�=�$29
8�for�30
4�SS�sup
port
Quantity
�assum
es�sup
ports�every�10
',�18
�+�22*2�+�7*6�=�10
4Add
ed�30%
�to�labo
r�for�concrete�installatio
n
220
4.6
- CO
ST E
STIM
ATE
- IN
STR
UM
ENTA
TIO
N
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal
TOTA
LEC
I No.
DO�Probe
�and
�Transmitter
CC�Con
trols�Quo
te���L.�Garcia���
9/16/10
Alum�Pipe�Stand�Mou
nt�w/�
sunshield,�NEM
A�4X�bo
x,�(1
)�24�V�+�
(1)�1
20�V�surge�sup
pressor,�to
ggle�
switch,�wiring
122750
687.5
3437.5
$41,250.00
3
Hach�List�Price
Hach�SC�100
�Con
troller,�((3(�2�probe
�controllers,�(3)�1�probe
�con
trollers)
121350
337.5
1687.5
$20,250.00
3Hach�List�Price
LDO�Probe
241510
377.5
1887.5
$45,300.00
3Hach�List�Price
115�V�Air�Blast�Cleaning�System
24800
200
1000
$24,000.00
3Hach�List�Price
Pole�M
ount�Kit
24380
95475
$11,400.00
3
Mod
ulating�BF
V6/09�Dezurik�Quo
te14"�Mod
ulating�BFV
246800
1700
8500
$204,000.00
3
CC�Con
trols�Quo
te���L.�Garcia���
9/16/10
NEM
A�4X�bo
x,�(1
)�24�V�+�(1)�1
20�V�
surge�supp
ressor,�toggle�sw
itch,�
wiring
242200
550
2750
$66,000.00
3SS�Unistrut�M
ount
2450
12.5
62.5
$1,500.00
3
Differen
tial�Pressure�Indicators�(Flow�M
eter)
5/09�PFS�Quo
te14"�Ve
nturi�Flow�Elemen
t24
3300
825
4125
$99,000.00
310/08�PFS�Quo
te`
Pressure�Indicatin
g�Transm
itter
481800
450
2250
$108,000.00
3CC
�Con
trols�Quo
te���L.�Garcia���
9/16/10
Alum�Pipe�Stand�Mou
nt�w/�sunshield
24650
162.5
812.5
$19,500.00
3Amerispo
nse.com,�9/19/10
4�20�m
a�Surge�Supp
ressor
48105
26.25
131.25
$6,300.00
3
PLC�an
d�Programming
Job�of�sim
ilar�scop
e/scale,�1/11
Programmab
le�Logic�Con
troller
1LS
50000
50000
$50,000.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Software
1LS
3000
3000
$3,000
.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Training/Calibratio
n/Docum
ents
1LS
10000
10000
$10,000.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Programming�and�Trou
blesho
oting
1LS
1500
015
000
$15,00
0.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Spare�Parts
1LS
10000
10000
$10,000.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
HMI�Program
ming�and�Re
ports
1LS
5000
050
000
$50,00
0.00
1/3
Sum
ECM�No.�1
$138,000.00
ECM�No.�2
$138,000.00
ECM�No.�3
$784,500.00
221
4.7
- CO
ST E
STIM
ATE
- EL
ECTR
ICA
LWPB
�City
WPB
�City
DIV
ISIO
N N
OD
ESC
RIP
TIO
NQ
UA
NTI
TYU
NIT
Mat
eria
lLa
bor
Equi
pTo
tal
INST
ALL
ATI
ON
TOTA
LEC
I No.
M
at In
dex
Labo
r Ind
ex98.10%
78.10%
Mot
or R
elat
edD5020�145�252
Motor�Install,�200�HP
3EA
########
$4,075.00
########
$46,335.23
1interpolated
Motor�Install,�300�HP
8EA
########
$6,112.00
########
$185,337.78
1D5020�145�024
Motor�Install,�1�HP
2EA
$700.00
$890.00
$1,381.79
$2,763.58
1Bu
ilding�Internal
D5025�120�116
14�Recep
tacles/2,000�sf
4584
SF$0.56
$1.95
$2.07
$9,499.47
1D5025�120�128
Light�S
witche
s/4�sw
itche
s4584
SF$0.10
$0.35
$0.37
$1,702.73
1D5020�208�068
Lightin
g,�Fluroescent�Fixtures
4584
SF$2.33
$4.88
$6.10
$27,948.69
126�24�16.30
Pane
lboard
1EA
$735.00
$605.00
$1,193.54
$1,193.54
1Wiring
26�05�19.90�328#350�XH
HW�(6
�per�300�HP)
5400
LF$8.45
$2.18
$9.99
$53,956.96
126�05�19.35�140��Terminate�#350
36EA
$51.00
$85.00
$116.42
$4,190.98
126�05�19.90�332#500�XH
HW�(3
�per�200�HP)
900LF
$14.00
$3.00
$16.08
$14,469.30
126�05�19.35�150��Terminate�#500
6EA
$66.00
$98.00
$141.28
$847.70
126�05�26.80�070#1�GND
2080
LF$1.66
$0.87
$2.31
$4,800.49
126�05�19.35�075��Terminate�#1
14EA
$10.90
$35.50
$38.42
$537.86
126�05�19.90�314#1
4120
LF$2.74
$0.98
$3.45
$14,227.68
326�05�19.35�075��Terminate�#1
48EA
$10.90
$35.50
$38.42
$1,844.08
326�05�19.90�312#2
1650
LF$2.14
$0.87
$2.78
$4,585.04
126�05�19.35�075��Terminate�#2
13EA
$8.65
$32.50
$33.87
$440.29
126�05�19.90�312#2
2060
LF$2.14
$0.87
$2.78
$5,724.35
326�05�19.35�075��Terminate�#2
24EA
$8.65
$32.50
$33.87
$812.84
326�05�23.10�0022�#12
2060
LF$0.18
$0.44
$0.52
$1,071.65
326�05�23.10�0033�#12
2060
LF$0.25
$0.49
$0.63
$1,293.56
326�05�26.80�033#12�GND
4120
LF$0.11
$0.30
$0.34
$1,409.91
326�05�19.35�163��Terminate�#12
48EA
$0.58
$7.85
$6.70
$321.59
326�05�23.10�0308�#14
1200
LF$0.67
$0.74
$1.24
$1,482.25
126�05�26.80�032#14�GND
2400
LF$0.07
$0.28
$0.29
$689.64
126�05�19.35�162��Terminate�#14
16EA
$0.43
$6.55
$5.54
$88.60
126�05�26.80�032#14�GND
6180
LF$0.07
$0.28
$0.29
$1,775.82
326�05�19.35�162��Terminate�#14
72EA
$0.43
$6.55
$5.54
$398.69
3Co
nduit
26�05�33.05�0701"�Co
nduit,�Alum
6000
LF$4.30
$4.90
$8.05
$48,271.20
126�05�33.05�0701"�Co
nduit,�Alum
4120
LF$4.30
$4.90
$8.05
$33,146.22
326�05�33.05�1103"�Co
nduit,�Alum
4500
LF$22.50
$8.70
$28.87
$129,902.40
133�77�19.17�080Con
crete�Handh
oles
2EA
$510.00
$582.50
$955.24
$1,910.49
133�17�19.17�700Ductbank�and�Co
nduit,�10��@
150LF
$171.25
$39.25
$198.65
$29,797.58
133�71�19.17�783Con
crete�(15�CY
/100�LF)
150LF
$1.61
$0.72
$2.14
$321.26
133�71�19.17�786Reinforcing�(1
0�Lb/LF)
150LF
$4.00
$3.40
$6.58
$986.91
1Exterior�Groun
ding/Lightning�Protection
26�05�26.80�013Groun
ding�Rod
s,�cop
per
8EA
$92.00
$98.00
$166.79
$1,334.32
126�05�26.80�1004/0�Groun
ding
380LF
$3.85
$1.38
$4.85
$1,844.76
126�41�13.13�050Air�Terminals
15EA
$24.50
$49.00
$62.30
$934.55
126�41�13.13�250Alum�Cable
320LF
$0.85
$1.40
$1.93
$616.72
126�41�13.13�300Arrestor
2EA
$78.50
$49.00
$115.28
$230.56
1Sum
ECM�No.�1
$577,020.85
ECM�No.�2
$577,020.85
ECM�No.�3
$639,047.24
222
5.0
- O&
M C
OST
S
Plant�Labor�Rate
Discoun
t�Rate�(in
terest)
CPI
Real�Rate
Planning�
Period
�(years)
36.45
0.04
70.02
50.02
220
Equipm
ent
O&M�Item
Cost
Amou
nt�
Unit
Ann
ual
NPV
ECM
Source
Diffusers
Replace�Mem
branes
$9.04
2000
0EA
$22,59
4$3
62,408
1,2,3
Sanitaire�respon
se�fo
r�Lesourdsville,�5/m
in�per�diffuser,�$6�replacem
ent�cost,�7�10�year�
Blow
ers
Replace�Filte
rs,�Inspe
cti o
$2,500
8EA
$20,000
$320,804
2,3
Rohrbacher�et.�al
LDO�Probe
sRe
place�Sensor�Caps
$140
24EA
$3,360
$53,89
53
Article:�"DO"ing�m
ore�with
�Less,�List�P
rice:�H
ach
Diffusers
Clean�Mem
branes
$36
160HR
$5,832
$93,54
61,2,3
Rosso,�Econo
mic�Im
plications�of�Fine�Po
re�Diffuser�Aging
Multi�Stage�Blow
ers
Typical�O
&M�based
�on�1
$1,500
8$1
2,00
0$1
92,482
11.5%
�Capita
l�Cost,�per�Roh
rbache
r�et.�al
Equipm
ent
O&M�Item
Cost
Amou
nt�
Ann
ual
NPV
ECM
Source
Manual�D
OCo
llect�DO�M
anually
�$10
936
5�$39
,913
�$64
0,20
83
30�M
ins�Pe
r�Ba
sin,�3�times�per�day
Mech�Diffuser�M
otors
Service�Motors
�$1,00
024
�$24
,000
�$38
4,96
41,2,3
1%�of�aerator�rep
lacemen
t�cost
Sum
Sum
Ann
ual
NPV
ECM��N
o.�1
$16,42
6$2
63,472
ECM��N
o.�2
$24,42
6$3
91,794
ECM��N
o.�3
�$12
,127
�$19
4,51
9
Equipm
ent
Useful�Life
Remaining�Rep
lacemeAmou
nt�
Total
NPV
ECM
Source
100�HP�Electric�M
otors
201000
�$6,025
24�$144,600
$01,2,3
RS�M
eans�26�71�13.10�5260�+�26�71�13.20�2100
100�HP�Motor�Starters
205
�$3,150
24�$75,600
�$67,806
1,2,3
RS�M
eans�26�24�19.40�0500
Replace�Aerators
205
24� $3,30
8,38
8�$2,96
7,30
31,2,3
6/17/11�Quo
te� f/� TSC�Ja
cobs
Sum
NPV
ECM��N
o.�1
�$3,03
5,10
9EC
M��N
o.�2
�$3,03
5,10
9EC
M��N
o.�3
�$3,03
5,10
9
O&M�Costs
O&M�No�Longer�Neccesary
Equipm
ent�R
eplacemen
t�Costs�Avoided
223
5.1
- O&
M C
OST
S - R
EPLA
CE
AER
ATO
RS
WPB
�City
WPB
�City
SOURC
EDESCR
IPTION
QUANTIT Y
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
M�No.
Mat�In
dexL
abor
Inde
x0.96
40.69
9
Kelly�Tractor�Quo
teCR
ANE�RE
NTA
L���4
0�TO
N�CAPA
CITY
6MO
$10,00
0.00
$60,00
0Re
move�Mech�Aerator
24EA
$500
.00
$349
.50
$8,388
Mechanical�A
erator�W
eight�X
�94.5TO
NS
$0New
�Mechanical�A
erators
24EA
1000
0035
000
1350
00$3
,240
,000
Sum
ECM�No.�1
$3,308
,388
.00
224
6.0 LIFE-CYCLE COST ANALYSIS INPUTS
CurrentCost per
kwH
Bond Rate CPI Inflation
Real Rate (interest)
EnergyInflation
PlanningPeriod(years)
CurrentHP
0.07 0.047 0.025 0.022 0.00083 20 1480.9
PowerFactor
If no Amp draws,
assumed% of
Nameplate
AvgBasins in Operation
0.84 0.85 7.2
Aerator # Nameplate HP
Avg Low SpeedAmps
Avg High Speed
Amps (1)
Months in low setting
Avg Amps Avg KW Avg Operating
HPA1-1 100 83.08 0 83 58.0 77.8A1-2 100 65.11 0 65 45.5 61.0A1-3 100 62.02 0 62 43.3 58.1A2-1 100 78.81 0 79 55.0 73.8A2-2 100 64.90 0 65 45.3 60.8A2-3 100 58.07 0 58 40.6 54.4A3-1 100 93.60 0 94 65.4 87.6A3-2 100 63.77 0 64 44.5 59.7A3-3 100 68.32 0 68 47.7 64.0A4-1 100 102.87 0 103 71.8 96.3A4-2 100 65.06 0 65 45.4 60.9A4-3 100 47.88 0 48 33.4 44.8B1-1 100 85.75 0 86 59.9 80.3B1 1 100 85.75 0 86 59.9 80.3B1-2 100 63.07 0 63 44.0 59.0B1-3 100 83.25 0 83 58.1 77.9B2-1 100 94.73 0 95 66.2 88.7B2-2 100 64.10 0 64 44.8 60.0B2-3 100 74.63 0 75 52.1 69.9B3-1 100 94.92 0 95 66.3 88.9B3-2 100 62.46 0 62 43.6 58.5B3-3 100 68.99 0 69 48.2 64.6B4-1 100 86.22 0 86 60.2 80.7B4-2 100 63.68 0 64 44.5 59.6 AvgB4-3 100 62.43 0 62 43.6 58.4 68.6
Total 1758 1227.5 1645.4
(1)�Data�based�on�Aug���Sep�2010�daily�amperage�recorded�by�Broward�County�North�Regional�WWTP
Blower # Nameplate HP
Factor(2) Adjusted HP
#1#2#3
Operating�HP�/�Nameplate�HP Zone�1�Avg Zone�2�Avg Zone�3�Avg kw hp0.69 84.2 59.9 61.5 230.5927 309.1054
225
6.1.
1 LI
FE-C
YCLE
CO
ST A
NA
LYSI
STh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
y S
avin
gs
NP
VC
apita
l and
O
&M
NP
VP
ayba
ckC
urre
nt C
ost p
er
kwH
Bon
d R
ate
CP
I Inf
latio
nR
eal R
ate
(inte
rest
)E
nerg
yIn
flatio
nP
lann
ing
Per
iod
(yea
rs)
Cur
rent
Tre
atm
ent -
1.0
mg/
L67
045
%$3
06,7
02($
4,95
5,56
7)3,47
5,76
1$������
12.75
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L18
012
%$8
2,34
3($
1,33
0,45
9)3,47
5,76
1$������
Com
plet
e N
Ox
-18
-1%
($8,
051)
$130
,091
3,47
5,76
1$������
Cur
rent
Tre
atm
ent -
1.0
mg/
L15
510
%$7
1,12
3($
1,14
9,17
7)77
0,85
4$���������
11.5
9C
urre
nt T
reat
men
t - 3
.0 m
g/L
224
15%
$102
,284
($1,
652,
664)
770,85
4$���������
7.44
Mod
ule
D s
avin
gsC
ompl
ete
NO
x25
117
%$1
14,8
39($
1,85
5,51
8)77
0,85
4$���������
6.50
309
Cur
rent
Tre
atm
ent -
1.0
mg/
L0
0%$0
$047
8,60
2$���������
47.0
7C
apita
l %C
urre
nt T
reat
men
t - 1
.5 m
g/L
340
23%
$155
,447
($2,
511,
658)
478,60
2$���������
5.97
1C
ompl
ete
NO
x38
426
%$1
75,5
47($
2,83
6,41
9)47
8,60
2$���������
5.37
Cur
rent
Tre
atm
ent -
1.0
mg/
L82
656
%$3
77,8
24($
6,10
4,74
4)4,
725,
218
$
14
.85
Cur
rent
Tre
atm
ent -
1.5
mg/
L74
350
%$3
40,0
74($
5,49
4,78
1)4,
725,
218
$
16
.75
Com
plet
e N
Ox
617
42%
$282
,334
($4,
561,
846)
4,72
5,21
8$
20.8
6*
Cur
rent
trea
tmen
t ind
icat
es e
nerg
y im
prov
emen
t rea
lized
by
treat
ing
to p
artia
l nitr
ifica
tion
at 0
.5 m
g/L,
whi
ch is
the
plan
ts c
urre
nt le
vel o
f tre
atm
ent
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8181
045
%$3
06,7
02($
4,95
5,56
7)16
,426
$������������
263,47
2$������������
(3,035
,109
)$��������
6,247,399
$�3,475,761
$��
12.7
5C
urre
nt T
reat
men
t - 3
.0 m
g/L
1481
1301
12%
$82,
343
($1,
330,
459)
16,426
$������������
263,47
2$������������
(3,035
,109
)$��������
6,247,399
$�3,475,761
$��
Com
plet
e N
Ox
1481
1499
-1%
($8,
051)
$130
,091
16,426
$������������
263,47
2$������������
(3,035
,109
)$��������
6,247,399
$�3,475,761
$��
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8165
556
%$3
77,8
24($
6,10
4,74
4)24
,426
$������������
391,79
4$������������
(3,035
,109
)$��������
6,889,931
$�4,246,615
$��
12.5
4C
urre
nt T
reat
men
t - 3
.0 m
g/L
1481
1077
27%
$184
,626
($2,
983,
123)
24,426
$������������
391,79
4$������������
(3,035
,109
)$��������
6,889,931
$�4,246,615
$��
33.9
3C
ompl
ete
NO
x14
8112
4716
%$1
0678
7($
172
542
8)24
426
$39
179
4$
(303
510
9)$
6889931
$4246615
$
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x14
8112
4716
%$1
06,7
87($
1,72
5,42
8)24,426
$������������
391,79
4$������������
(3,035,109
)$��������
6,889,931
$�4,246,615
$��
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8165
556
%$3
77,8
24($
6,10
4,74
4)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
7,954,846
$�4,725,218
$��
14.8
5C
urre
nt T
reat
men
t - 1
.5 m
g/L
1481
737
50%
$340
,074
($5,
494,
781)
(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
7,954,846
$�4,725,218
$��
16.7
5C
ompl
ete
NO
x14
8186
442
%$2
82,3
34($
4,56
1,84
6)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
7,954,846
$�4,725,218
$��
20.8
6
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
226
6.1.
1 LI
FE-C
YCLE
CO
ST A
NA
LYSI
STh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
y S
avin
gs
NP
VC
apita
l and
O
&M
NP
VP
ayba
ckC
urre
nt C
ost p
er
kwH
Bon
d R
ate
CP
I Inf
latio
nR
eal R
ate
(inte
rest
)E
nerg
yIn
flatio
nP
lann
ing
Per
iod
(yea
rs)
Cur
rent
Tre
atm
ent -
1.0
mg/
L67
045
%$3
06,7
02($
4,95
5,56
7)2,22
6,28
2$������
7.38
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L18
012
%$8
2,34
3($
1,33
0,45
9)2,22
6,28
2$������
47.23
Com
plet
e N
Ox
-18
-1%
($8,
051)
$130
,091
2,22
6,28
2$������
Cur
rent
Tre
atm
ent -
1.0
mg/
L15
510
%$7
1,12
3($
1,14
9,17
7)64
2,34
7$���������
9.04
Cur
rent
Tre
atm
ent -
3.0
mg/
L22
415
%$1
02,2
84($
1,65
2,66
4)64
2,34
7$���������
5.86
Mod
ule
D s
avin
gsC
ompl
ete
NO
x25
117
%$1
14,8
39($
1,85
5,51
8)64
2,34
7$���������
5.13
309
Cur
rent
Tre
atm
ent -
1.0
mg/
L0
0%$0
$026
5,61
9$���������
33.0
4C
apita
l %C
urre
nt T
reat
men
t - 1
.5 m
g/L
340
23%
$155
,447
($2,
511,
658)
265,61
9$���������
4.71
0.8
Com
plet
e N
Ox
384
26%
$175
,547
($2,
836,
419)
265,61
9$���������
4.25
Cur
rent
Tre
atm
ent -
1.0
mg/
L82
656
%$3
77,8
24($
6,10
4,74
4)3,
134,
248
$
9.
52C
urre
nt T
reat
men
t - 1
.5 m
g/L
743
50%
$340
,074
($5,
494,
781)
3,13
4,24
8$
10.6
7C
ompl
ete
NO
x61
742
%$2
82,3
34($
4,56
1,84
6)3,
134,
248
$
13
.07
* C
urre
nt tr
eatm
ent i
ndic
ates
ene
rgy
impr
ovem
ent r
ealiz
ed b
y tre
atin
g to
par
tial n
itrifi
catio
n at
0.5
mg/
L, w
hich
is th
e pl
ants
cur
rent
leve
l of t
reat
men
t
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8181
045
%$3
06,7
02($
4,95
5,56
7)16
,426
$������������
263,47
2$������������
(3,035
,109
)$��������
4,997,919
$�2,226,282
$��
7.38
Cur
rent
Tre
atm
ent -
3.0
mg/
L14
8113
0112
%$8
2,34
3($
1,33
0,45
9)16
,426
$������������
263,47
2$������������
(3,035
,109
)$��������
4,997,919
$�2,226,282
$��
47.2
3C
ompl
ete
NO
x14
8114
99-1
%($
8,05
1)$1
30,0
9116
,426
$������������
263,47
2$������������
(3,035
,109
)$��������
4,997,919
$�2,226,282
$��
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8165
556
%$3
77,8
24($
6,10
4,74
4)24
,426
$������������
391,79
4$������������
(3,035
,109
)$��������
5,511,945
$�2,868,629
$��
7.67
Cur
rent
Tre
atm
ent -
3.0
mg/
L14
8110
7727
%$1
84,6
26($
2,98
3,12
3)24
,426
$������������
391,79
4$������������
(3,035
,109
)$��������
5,511,945
$�2,868,629
$��
18.9
2C
ompl
ete
NO
x14
8112
4716
%$1
0678
7($
172
542
8)24
426
$39
179
4$
(303
510
9)$
5511945
$2868629
$47
97
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x14
8112
4716
%$1
06,7
87($
1,72
5,42
8)24,426
$������������
391,79
4$������������
(3,035,109
)$��������
5,511,945
$�2,868,629
$��
47.9
7C
urre
nt T
reat
men
t - 1
.0 m
g/L
1481
655
56%
$377
,824
($6,
104,
744)
(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
6,363,877
$�3,134,248
$��
9.52
Cur
rent
Tre
atm
ent -
1.5
mg/
L14
8173
750
%$3
40,0
74($
5,49
4,78
1)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
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$�3,134,248
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ompl
ete
NO
x14
8186
442
%$2
82,3
34($
4,56
1,84
6)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
6,363,877
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13.0
7
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
227
6.1.
1 LI
FE-C
YCLE
CO
ST A
NA
LYSI
STh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
ING
loba
l Cos
t Cal
cula
tion
Par
amet
ers
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
y S
avin
gs
NP
VC
apita
l and
O
&M
NP
VP
ayba
ckC
urre
nt C
ost p
er
kwH
Bon
d R
ate
CP
I Inf
latio
nR
eal R
ate
(inte
rest
)E
nerg
yIn
flatio
nP
lann
ing
Per
iod
(yea
rs)
Cur
rent
Tre
atm
ent -
1.0
mg/
L67
045
%$3
06,7
02($
4,95
5,56
7)5,34
9,98
1$������
22.13
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L18
012
%$8
2,34
3($
1,33
0,45
9)5,34
9,98
1$������
Com
plet
e N
Ox
-18
-1%
($8,
051)
$130
,091
5,34
9,98
1$������
Cur
rent
Tre
atm
ent -
1.0
mg/
L15
510
%$7
1,12
3($
1,14
9,17
7)96
3,61
4$���������
15.6
9C
urre
nt T
reat
men
t - 3
.0 m
g/L
224
15%
$102
,284
($1,
652,
664)
963,61
4$���������
9.92
Mod
ule
D s
avin
gsC
ompl
ete
NO
x25
117
%$1
14,8
39($
1,85
5,51
8)96
3,61
4$���������
8.64
309
Cur
rent
Tre
atm
ent -
1.0
mg/
L0
0%$0
$079
8,07
7$���������
82.3
1C
apita
l %C
urre
nt T
reat
men
t - 1
.5 m
g/L
340
23%
$155
,447
($2,
511,
658)
798,07
7$���������
7.92
1.3
Com
plet
e N
Ox
384
26%
$175
,547
($2,
836,
419)
798,07
7$���������
7.11
Cur
rent
Tre
atm
ent -
1.0
mg/
L82
656
%$3
77,8
24($
6,10
4,74
4)7,
111,
672
$
24
.15
Cur
rent
Tre
atm
ent -
1.5
mg/
L74
350
%$3
40,0
74($
5,49
4,78
1)7,
111,
672
$
27
.64
Com
plet
e N
Ox
617
42%
$282
,334
($4,
561,
846)
7,11
1,67
2$
35.6
2*
Cur
rent
trea
tmen
t ind
icat
es e
nerg
y im
prov
emen
t rea
lized
by
treat
ing
to p
artia
l nitr
ifica
tion
at 0
.5 m
g/L,
whi
ch is
the
plan
ts c
urre
nt le
vel o
f tre
atm
ent
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8181
045
%$3
06,7
02($
4,95
5,56
7)16
,426
$������������
263,47
2$������������
(3,035
,109
)$��������
8,121,618
$�5,349,981
$��
22.1
3C
urre
nt T
reat
men
t - 3
.0 m
g/L
1481
1301
12%
$82,
343
($1,
330,
459)
16,426
$������������
263,47
2$������������
(3,035
,109
)$��������
8,121,618
$�5,349,981
$��
Com
plet
e N
Ox
1481
1499
-1%
($8,
051)
$130
,091
16,426
$������������
263,47
2$������������
(3,035
,109
)$��������
8,121,618
$�5,349,981
$��
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8165
556
%$3
77,8
24($
6,10
4,74
4)24
,426
$������������
391,79
4$������������
(3,035
,109
)$��������
8,956,910
$�6,313,595
$��
20.9
2C
urre
nt T
reat
men
t - 3
.0 m
g/L
1481
1077
27%
$184
,626
($2,
983,
123)
24,426
$������������
391,79
4$������������
(3,035
,109
)$��������
8,956,910
$�6,313,595
$��
72.3
2C
ompl
ete
NO
x14
8112
4716
%$1
0678
7($
172
542
8)24
426
$39
179
4$
(303
510
9)$
8956910
$6313595
$
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x14
8112
4716
%$1
06,7
87($
1,72
5,42
8)24,426
$������������
391,79
4$������������
(3,035,109
)$��������
8,956,910
$�6,313,595
$��
Cur
rent
Tre
atm
ent -
1.0
mg/
L14
8165
556
%$3
77,8
24($
6,10
4,74
4)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
##########
7,111,672
$��
24.1
5C
urre
nt T
reat
men
t - 1
.5 m
g/L
1481
737
50%
$340
,074
($5,
494,
781)
(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
##########
7,111,672
$��
27.6
4C
ompl
ete
NO
x14
8186
442
%$2
82,3
34($
4,56
1,84
6)(12,12
7)$�����������
(194
,519
)$�����������
(3,035
,109
)$��������
##########
7,111,672
$��
35.6
2
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
- All
effic
ienc
y an
d D
O v
alue
s ar
e su
ppor
ted
by d
ata
com
plile
d in
the
man
uscr
ipt.
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
con
serv
ativ
ely
mai
ntai
n D
O a
t ave
rage
of 3
mg/
L Th
is o
ptio
n as
sum
es c
onve
ntio
nal m
ulti-
stag
e ce
ntrif
ugal
blo
wer
s at
62%
avg
. effi
cien
cy.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
72%
effi
cien
cy w
ith tu
rbo
blow
ers
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y m
odel
ing
diur
nal h
ourly
airf
low
requ
irem
ents
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (2
mg/
L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
228
APPENDIX B-3 – BROWARD CO. N. REGIONAL WWTP RECORD DRAWINGS
229
230
231
232
233
234
APPENDIX C-1 – PLANTATION REGIONAL WWTP PRELIMINARY DESIGN DRAWINGS
235
236
237
238
239
240
APPENDIX C-2 – PLANTATION REGIONAL WWTP DATA SPREADSHEETS
241
PLANTATION- ENERGY EFFICIENCY ANALYSIS SPREADSHEETSSPREADSHEET TABLE OF CONTENTS
1.1 INFLUENT EFFLUENT SPECIFIER1.2 FLOW PROJECTION2.0 AERATION CALCULATIONS - GLOBAL PARAMETERS2.1 AERATION CALCULATIONS - DIFFUSERS2.2 AERATION CALCULATIONS - TURBO BLOWERS2.3 AERATION CALCULATIONS - 1.5 MG/L DO CONTROL3.1 SYSTEM DESIGN - SIZE PIPES3.2 SYSTEM DESIGN - ESTIMATE LOSSES THROUGH PIPES3.4 SYSTEM DESIGN - BLOWER DESIGN3.3 SYSTEM DESIGN - SYSTEM CURVE4.0 - COST ESTIMATE - SUMMARY4.1 - COST ESTIMATE - DEMOLITION4.2 - COST ESTIMATE - BLOWERS4.3 - COST ESTIMATE - DIFFUSERS4.4 - COST ESTIMATE - STRUCTURAL4.5 - COST ESTIMATE - MECHANICAL PIPING4.6 - COST ESTIMATE - INSTRUMENTATION4.7 - COST ESTIMATE - ELECTRICAL5.0 - O&M COSTS5.1 - O&M COSTS - REPLACE AERATORS6.0�LIFE�CYCLE�COST�ANALYSIS�INPUTS6.1.1�LIFE�CYCLE�COST�ANALYSIS6.1.2�LIFE�CYCLE�COST�ANALYSIS�(LOW�RANGE)6.1.3�LIFE�CYCLE�COST�ANALYSIS�(HIGH�RANGE)6.2�LIFE�CYCLE�COST�ANALYSIS�SUMMARY
242
1.1
INFL
UEN
T EF
FLU
ENT
SPEC
IFIE
RTh
is s
prea
dshe
et is
a c
ontin
uatio
n of
the
prev
ious
Influ
ent-E
fflue
nt S
umm
ary
spre
adsh
eet.
All
the
valu
es o
nth
is s
prea
dshe
et a
re in
serte
d di
rect
ly in
to th
e 3.
1 - 3
.6 A
erat
ion
Cal
cula
tion
spre
ashe
ets
that
follo
w.
2007
- 20
09 3
Yea
r Ave
rage
PRIM
AR
YPR
IMA
RY
Avg
INF
FLO
W E
FF C
BO
DEF
F TS
SEF
F C
BO
DEF
F W
AS
VSS
INF
TKN
EFF
NH
3D
OSR
TM
GD
LBS
LBS
LBS.
LBS
LBS
LBS.
mg/
LD
ays
Min
Day
9.52
3,35
93,
974
742,
278
1,37
00
1.5
30.0
AD
F14
.21
7,42
76,
737
173
2,84
91,
861
0M
MA
DF
16.0
611
,614
10,1
3125
63,
263
2,23
70
Max
Day
21.8
822
,580
61,3
5850
04,
159
2,99
20
2007
- 20
09 3
Yea
r Ave
rage
- A
djus
ted
to 2
011-
2031
AD
FPR
IMA
RY
PRIM
AR
YIN
F FL
OW
EFF
CB
OD
EFF
TSS
EFF
CB
OD
EFF
WA
S VS
SIN
F TK
NEF
F N
H3
MG
DLB
SLB
SLB
S.LB
SLB
SLB
S.M
in D
ay10
.44
3,68
24,
356
812,
498
1,50
20
AD
F15
.58
8,14
27,
385
190
3,12
32,
040
0M
MA
DF
17.6
012
,732
11,1
0628
13,
577
2,45
30
Max
Day
23.9
924
,754
67,2
6454
84,
559
3,28
00
2007
- 20
09 3
Yea
r Ave
rage
- A
djus
ted
to D
esig
n Fl
ow o
f 16.
9 M
GD
PRIM
AR
YPR
IMA
RY
INF
FLO
W E
FF C
BO
DEF
F TS
SEF
F C
BO
DEF
F W
AS
VSS
INF
TKN
EFF
NH
3M
GD
LBS
LBS
LBS.
LBS
LBS
LBS.
Min
Day
12.6
64,
467
5,28
599
3,03
01,
823
0A
DF
18.9
09,
879
8,96
123
03,
789
2,47
50
MM
AD
F21
.36
15,4
4813
,474
341
4,34
02,
976
0M
ax D
ay29
.11
30,0
3381
,609
665
5,53
13,
979
0
243
1.2 FLOW PROJECTIONThis spreadsheet summarizes the Flow Projection through the 20 year design horizon
2010 86208 161 5,066 13.882011 87219.2 161 5,125 14.042012 88230.4 161 5,185 14.212013 89241.6 161 5,244 14.372014 90252.8 161 5,304 14.532015 91264 161 5,363 14.692016 92275.2 161 5,423 14.862017 93286.4 161 5,482 15.022018 94297.6 161 5,541 15.182019 95308.8 161 5,601 15.342020 97191 161 5,711 15.652021 98202.2 161 5,771 15.812022 99213.4 161 5,830 15.972023 100224.6 161 5,890 16.142024 101235.8 161 5,949 16.302025 102277 161 6,010 16.472026 103288.2 161 6,070 16.632027 104299.4 161 6,129 16.792028 105310.6 161 6,189 16.962029 106322 161 6,248 17.122030 106727 161 6,272 17.18
15.58
YearPlantationPopulation
WastewaterGeneration
TotalAnnual(MG)
AADF(MGD)
80000
85000
90000
95000
100000
105000
110000
2005 2010 2015 2020 2025 2030 2035
Cap
ita
Year
Population Projection
244
2.0 AERATION CALCULATIONS - GLOBAL PARAMETERSSpreadsheet 3.1 - 3.5 calculates the amount of air and horsepower need to treat various flowrates and loading rates throughout the plant. 3.0 Aeration Calculations - Global Paramters spreadsheet specifies the golbale variables that are in put to each aeration calculation spreadsheet.
Area�under�Aeration�per�Basin�(ft2)�= 12675 Manual�DO�Control�O2�(mg/L) 3#�of�basins�online 3 Auto�DO�Control�O2�(mg/L) 1.5Side�water�Depth�(ft)�=� 12 ft MSC�Blower�Efficiency 0.62Diffuser�Submergence�(ft)�=� 11 ft Turbo�Blower�Efficiency 0.72Equation�For�System�Curve 2.51E�09 *�x^2 2�Concentration�at�Max�Day�(mg/L) 0.5Number�of�Diffusers�per�Basin�=� 2000 Pre�ECM�Existing�DO�(mg/L) 1.5Site�Elevation�(ft�above�MSL)�=� 10Minimum�Mixing�Requirements�(scfm/ft2) 0.12 Dold�predicted�yield 0.52Minimum�Flow�per�Diffuser�(scfm) 0.5 non�fully�nitrifying�assume�SRT�4�daysMaximum�Flow�per�Diffuser�(scfm) 3.0General�Temperature 25Beta�(unitless)=� 0.98 unitless fup 0.08 Biowin�settled�defaultPatm�(psi)�=� 14.7 psi VSS/TSS 0.85Patm�(mid�depth,�ft�wc/2/2.31�psi,�psi)�=� 2.38 psiCsth�(per�App�D�for�mech�aer,�mg/L)�= 8.24 mg/LCs20�(DO�@�20�deg�C,�1�atm,�mg/L)�=� 9.08 mg/LCstH*�(mg/L)�= 9.57Dens�Air�(lb/cf)�=� 0.0750 lb/cfMass�Fraction�O2�in�air�=� 0.2315Alpha�=� 0.43Alpha�for�complete�nitrification�=� 0.5Average�of�minimum�SOTE a
Figure 2.10TauTemp.
1.60 1.45 1.24
10 1.1215 120 0.9125 0.8330 0.7735 0.7140
Submergence = 20 00 ft
y = 4.08E-04x2 - 3.82E-02x + 1.60E+00R² = 9.98E-01
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30 35 40
Tau
(dim
ensi
onle
ss)
Temperature (C)
Tau vs. Temperature
Average Minimum Average Minimum Results from trendline in chartAir SOTE SOTE SOTE SOTE
Flow (%) (%) (%/ft) (%/ft) Constants�for�the�following�formula:�ax4+bx3+cx2+dx+e(SCFM/Unit)
46.83 41.25 2.34 2.06 Avg SOTE "a"0.59 42.50 37.98 2.13 1.90 Avg SOTE 0.05140.88 41.26 37.37 2.06 1.87 Avg SOTE �0.46031.00 39.89 36.95 1.99 1.85 Avg SOTE 1.54051.18 38.48 35.92 1.92 1.80 Avg SOTE �2.34731.47 38.33 35.90 1.92 1.80 Min SOTE 3.27791.75 37.52 35.39 1.88 1.77 Min SOTE 0.04672.06 37.21 35.35 1.86 1.77 Min SOTE �0.40152.35 37.07 35.20 1.85 1.76 Min SOTE 1.27242.50 36.87 35.18 1.84 1.76 Min SOTE �1.79842.65 36.69 35.01 1.83 1.75 2.75262.94 36.66 35.00 1.83 1.753.00
Average Minimum Average MinimumAir SOTE SOTE SOTE SOTE
Flow (%) (%) (%/ft) (%/ft)(SCFM/Unit)
40.58 35.74 2.34 2.060.59 36.83 32.91 2.13 1.900.88 35.75 32.38 2.06 1.871.00 34.56 32.02 1.99 1.851.18 33.34 31.12 1.92 1.801.47 33.21 31.11 1.92 1.801.75 32.51 30.67 1.88 1.772.06 32.24 30.63 1.86 1.772.35 32.12 30.57 1.85 1.762.50 31.95 30.48 1.84 1.762.65 31.79 30.34 1.83 1.752.94 31.77 30.33 1.83 1.753.00
Submergence = 20.00-ft
Submergence = 17.33-ft y�=�0.0514x4 � 0.4603x3 +�1.5405x2 � 2.3473x�+�3.2779R²�=�0.9987
y�=�0.0467x4 � 0.4015x3 +�1.2724x2 � 1.7984x�+�2.7526R²�=�0.9944
1.50
1.60
1.70
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50
SOTE�%�/�fo
ot�of�d
iffuser�sub
mergence
SCFM/Diffuser
SOTE�vs.�SCFM/diffuser�Sanitaire�� Silver�Series�II��9"�Membrane�Disc�Diffuser�
Average�SOTE
Min.�SOTE
Poly.�(Average�SOTE)
Poly.�(Min.�SOTE)
245
2.1
AER
ATI
ON
CA
LCU
LATI
ON
S - D
IFFU
SER
SS
prea
dshe
et 3
.1 -
3.5
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
1 A
erat
ion
Cal
cula
tions
- D
iffus
ers
spre
adsh
eet p
redi
cts
the
effic
ienc
y im
prov
emen
t by
upgr
adin
g to
fine
bub
ble
diffu
sers
with
no
othe
r EC
Ms.
Cur
Tre
atA
DF
AD
F +
Nit
Min
Day
Min
Day
AD
F A
DF
MM
AD
FM
MA
DF
MD
FM
DF
Cur
Tre
at
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2007���2009
2.�In
puts
MGD
15.58
15.58
15.58
9.52
12.66
18.90
18.90
21.36
21.36
29.11
29.11
14.21
Num
ber�of�Basins�Online
33
33
33
33
33
33
So�=�CBO
Dinf
8,142
8,142
8,142
3,359
4,467
9,879
9,879
15,448
15,448
30,033
30,033
(lb/day)
7,427
S�=�CB
ODeff
190
190
190
7499
230
230
341
341
665
665(lb
/day)
173
Eq.�8�15�(w
here�hilighted),�PxBio�=�
2,620
4,409
2,620
2,008
2,671
3,179
3,179
3,423
3,423
�1,210
3,423(lb
/day)
2,390
TKN�=�
2,040
2,040
2,040
1,370
1,823
2,475
2,475
2,976
2,976
3,979
3,979(lb
/day)
1,861
NH3�eff�=
�0
1039
00
00
00
00
0(lb
/day)
0CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
1.5
33
33
33
33
0.5
0.5mg/L
1.5
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
25Alpha�=�
0.5
0.43
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5un
itless
0.43
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
aa
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,726
472
1,726
1,129
1,502
2,094
2,094
2,565
2,565
4,124
3,568(lb
/day)
1,574
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
18,511
10,541
18,511
8,135
10,820
22,459
22,459
34,283
34,283
74,084
65,097
(lb/day)
16,886
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.43
0.29
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.49
0.49
0.38
SOR�=�
42,992
36,310
54,835
24,099
32,053
66,530
66,530
101,558
101,558
150,402
132,158(lb
/day)
44,909
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
1,720
1,452
2,193
964
1,282
2,661
2,661
4,062
4,062
6,016
5,286
1,796
TotalN
umbe
rof
Diffusers=
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
10500
Total�N
umbe
r�of�Diffusers�=�
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
10,500
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
1.09
1.75
0.64
0.93
2.15
2.15
3.30
3.30
4.03
3.83
1.33
Diffuser�Flow,�scfm/diffuser�=�
1.33
1.09
1.75
0.64
0.93
2.15
2.15
3.30
3.30
4.03
3.84
0.73
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.61
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
21.55%
22.30%
20.94%
25.28%
23.07%
20.63%
20.63%
20.49%
20.49%
24.90%
22.97%
23.50%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
7980
6512
10475
3813
5556
12896
12896
19827
19827
24157
23010
7,645
27.38324
27.6106
26.90513
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
291
236
389
137
200
490
490
815
815
1056
989hp
279
Dynam
ic�Losses
0.16
0.11
0.28
0.04
0.08
0.42
0.42
0.99
0.99
1.46
1.33
psi
0.16
Wire�to�Air�Eff�=�
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
0.62
Unitle
ss0.62
e=100%
*((P1+14.7)/14.7)0.283�1)/�1
��(P2
+14.7)/14.7)0.283�1)/�2)/((P1+14.7)/14.7)�0
.283�1)/�2
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
7803
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
FALSE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
246
2.2
AER
ATI
ON
CA
LCU
LATI
ON
S - T
UR
BO
BLO
WER
SS
prea
dshe
et 2
.1 -
2.3
calc
ulat
es th
e am
ount
of a
ir an
d ho
rsep
ower
nee
d to
trea
t var
ious
flow
rate
s an
d lo
adin
g ra
tes
thro
ugho
ut th
e pl
ant.
2.
2 A
erat
ion
Cal
cula
tions
-Tur
bo B
low
ers
spre
adsh
eet p
redi
cts
effic
ienc
y im
prov
emen
t of f
ine
bubb
le d
iffus
ers
with
turb
o bl
ower
s.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
F
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�In
puts
MGD
15.58
15.58
15.58
9.52
12.66
18.90
18.90
21.36
21.36
29.11
29.11
Num
ber�of�Basins�Online
33
33
33
33
33
3So�=�CBO
Dinf
8,142
8,142
8,142
3,359
4,467
9,879
9,879
15,448
15,448
30,033
30,033
(lb/day)
S�=�CB
ODeff
190
190
190
7499
230
230
341
341
665
665(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
2,620
3,633
2,620
2,008
2,671
3,179
3,179
3,423
3,423
�1,210
3,423(lb
/day)
TKN�=�
2,040
2,040
2,040
1,370
1,823
2,475
2,475
2,976
2,976
3,979
3,979(lb
/day)
NH3�eff�=
�0
1039
00
00
00
00
0(lb
/day)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
1.5
33
33
33
33
0.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.5
0.43
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,726
565
1,726
1,129
1,502
2,094
2,094
2,565
2,565
4,124
3,568(lb
/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
18,511
12,047
18,511
8,135
10,820
22,459
22,459
34,283
34,283
74,084
65,097
(lb/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.43
0.29
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.49
0.49
SOR�=�
42,992
41,495
54,835
24,099
32,053
66,530
66,530
101,558
101,558
150,402
132,158(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
1,720
1,660
2,193
964
1,282
2,661
2,661
4,062
4,062
6,016
5,286
TotalN
umbe
rof
Diffusers=
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
Total�N
umbe
r�of�Diffusers�=�
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
1.28
1.75
0.64
0.93
2.15
2.15
3.30
3.30
4.03
3.83
Diffuser�Flow,�scfm/diffuser�=�
1.33
1.28
1.75
0.64
0.93
2.15
2.15
3.30
3.30
4.03
3.84
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
21.55%
21.68%
20.94%
25.28%
23.07%
20.63%
20.63%
20.49%
20.49%
24.90%
22.97%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
7980
7655
10475
3813
5556
12896
12896
19827
19827
24157
23010
31.86246
31.24467
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
251
240
335
118
173
422
422
702
702
909
851hp
Dynam
ic�Losses
0.16
0.15
0.28
0.04
0.08
0.42
0.42
0.99
0.99
1.46
1.33
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
247
2.3
AER
ATI
ON
CA
LCU
LATI
ON
S - 1
.5 M
G/L
DO
CO
NTR
OL
Spr
eads
heet
2.1
- 2.
3 ca
lcul
ates
the
amou
nt o
f air
and
hors
epow
er n
eed
to tr
eat v
ario
us fl
owra
tes
and
load
ing
rate
s th
roug
hout
the
plan
t.
2.3
Aer
atio
n C
alcu
latio
ns -2
MG
/L D
o C
ontro
l spr
eads
heet
pre
dict
s ef
ficie
ncy
impr
ovem
ent o
f fin
e bu
bble
diff
user
s, tu
rbo
blow
ers,
and
DO
Con
trol
.
Cur
Tre
atA
DF
AD
FM
in D
ayM
in D
ayA
DF
AD
FM
MA
DF
MM
AD
FM
DF
MD
F
11��3
1�ADF11��3
1�ADF11��3
1�ADF
Curren
tDesign
Design
Des�+�Nit
Des
Des�+�Nit
Des
Des�+�Nit
2.�In
puts
MGD
15.58
15.58
15.58
9.52
12.66
18.90
18.90
21.36
21.36
29.11
29.11
Num
ber�of�Basins�Online
33
33
33
33
33
3So�=�CBO
Dinf
8,142
8,142
8,142
3,359
4,467
9,879
9,879
15,448
15,448
30,033
30,033
(lb/day)
S�=�CB
ODeff
190
190
190
7499
230
230
341
341
665
665(lb
/day)
Eq.�8�15�(w
here�hilighted),�PxBio�=�
2,620
3,633
2,620
2,008
2,671
3,179
3,179
3,423
3,423
�1,210
3,423(lb
/day)
TKN�=�
2,040
2,040
2,040
1,370
1,823
2,475
2,475
2,976
2,976
3,979
3,979(lb
/day)
NH3�eff�=
�0
1039
00
00
00
00
0(lb
/day)
(0.5�m
g/L)
CL�(o
perat.�oxygen�concen
tration,�m
g/L�)�=
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
0.5
0.5mg/L
T�(deg�C)
2525
2525
2525
2525
2525
25de
g�C
Alpha�=�
0.5
0.43
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5un
itless
Average�of�m
inim
um�SOTE
aa
aa
aa
aa
aa
a
3.�AOR�Ca
lculations
Eq.�8�18
TKNinf���NH3eff���0.12(PxBio)�=
�NOx�=�
1,726
565
1,726
1,129
1,502
2,094
2,094
2,565
2,565
4,124
3,568(lb
/day)
Eq.�8�17
1.6*1.16
*(So���S)���1.42
(PxBio)�+
�4.33(NOx)�=�AO
18,511
12,047
18,511
8,135
10,820
22,459
22,459
34,283
34,283
74,084
65,097
(lb/day)
4.�SOR�Ca
lculations
Tau=
�0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
Eq�5�55
AOR�/�SO
R�=�{[(Beta*CstH*���C
L)/Cs20][1.024^(
0.43
0.37
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.49
0.49
SOR�=�
42,992
32,533
42,992
18,894
25,130
52,161
52,161
79,623
79,623
150,402
132,158(lb
/day)
5.�Aeration�Dem
and�Ca
lculations
Air�req
uired�at�100%�Efficiency�=�
1,720
1,301
1,720
756
1,005
2,086
2,086
3,185
3,185
6,016
5,286
TotalN
umbe
rof
Diffusers=
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
6000
Total�N
umbe
r�of�Diffusers�=�
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
6,000
Diffuser�Flow,�scfm/diffuser�(m
acro�inpu
t)�=�
1.33
0.94
1.33
0.46
0.67
1.65
1.65
2.61
2.61
4.03
3.83
Diffuser�Flow,�scfm/diffuser�=�
1.33
0.94
1.33
0.46
0.67
1.65
1.65
2.61
2.61
4.03
3.84
Differen
ce�=�
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
SOTE�at�D
es�Sub
m�and
�Diff�Flow�=
21.55%
22.97%
21.55%
27.27%
24.93%
21.03%
21.03%
20.31%
20.31%
24.90%
22.97%
SCFM
�=�SOTR
�/�(�SO
TE�*�60�min/hr�*�24
�hr/day�
7980
5664
7980
2771
4031
9921
9921
15679
15679
24157
23010
32.19375
31.79986
6.�Pow
er�Dem
and�Ca
lculations
Pw�=[(W*R
*T1)/(550*n*
Eff)]*[(P2
/P1)^.283���1
]Pw
�(blower�horsepo
wer�req
uired)�=�
251
176
251
85124
316
316
527
527
909
851hp
Dynam
ic�Losses
0.16
0.08
0.16
0.02
0.04
0.25
0.25
0.62
0.62
1.46
1.33
psi
Wire�to�Air�Eff�=�
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
0.72
Unitle
ss
7. C
heck
s
Minim
um�M
ixing�Airflo
w�Req
uiremen
t�(scfm
)4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
4563
Minim
um�M
ixing�Re
quirem
ent�M
et?
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Is�Diffuser�Flow�W
ithin�Range?
TRUE
TRUE
TRUE
FALSE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
All�Equatio
ns�referen
ced,�(M
etcalf�&�Edd
y,�2003)
248
3.1
SYST
EM D
ESIG
N -
SIZE
PIP
ESTh
is s
prea
dshe
et d
emon
stra
tes
the
sizi
ng o
f the
pro
pose
d ae
ratio
n pr
oces
s ai
r pip
es a
t Tra
in 1
.P
er T
able
5-2
8 - M
etca
lf &
Edd
yFr
om 5
th O
rder
Cur
ve F
itTy
pica
l air
velo
citie
s in
aer
atio
n Fi
gure
4-1
- S
atur
atio
n W
RH
Inle
t =
0.41
head
er p
ipes
Wat
er v
apor
pre
ssur
e (p
sT d
isch
arge�=
175
Fbe
cal
cula
ted
with
the
foll
Pdi
scha
rge
=6.
5ps
igPi
pe D
iaVe
loci
tyV
P =
a*T
5+�b*
T4+�c*T3
+V
p ac
t6.
7169
0069
8In
fpm
Whe
re:
VP
std
0.33
9020
461
- 312
00 -
1800
a =
2.27
E-1
1A
irflo
ws
4 - 1
018
00 -
3000
b =
-2.5
E-1
0A
vera
ge A
nnua
l Air
Flow
:10
,528
scfm
1000
6ac
fm12
- 24
2700
- 40
00c
=5.
08E
-07
Max
imum
Mon
th A
ir Fl
ow:
11,7
34sc
fm11
153
acfm
30 -
6038
00 -
6500
d =
7.42
E-0
6M
axim
um D
ay A
ir Fl
ow:
20,0
74sc
fm19
079
acfm
e =
0.00
1485
f =0.
0162
74
Tota
l Air
Flow
:11
,153
scfm
19,0
79sc
fmM
inim
um P
ipe
Size
to M
eet V
eloc
ity C
riter
ia:
30in
Act
ual V
eloc
ity:
2,27
2fp
m3,
887
fpm
Flow
to A
erat
ion
Trai
ns 1
& 2
:0.
67ea
0.67
eaA
ir Fl
ow P
er T
reat
men
t Tra
in:
7,43
5sc
fm12
,720
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:24
inA
ctua
l Vel
ocity
:2,
367
fpm
4,04
9fp
m
Spl
it 2
0.67
ea0.
67ea
Max
. Mon
thP
eak
Day
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
Spl
it 2
0.67
ea0.
67ea
Air
Flow
to Z
ones
2, 3
4,95
7sc
fm8,
480
scfm
Min
imum
Pip
e Si
ze to
Mee
t Vel
ocity
Crit
eria
:20
inA
ctua
l Vel
ocity
:2,
272
fpm
3,88
7fp
m
Spl
it 3
0.33
0.33
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
249
3.2
SYST
EM D
ESIG
N -
ESTI
MA
TE L
OSS
ES T
HR
OU
GH
PIP
ESFr
om 5
th O
rder
Cur
ve F
it of
Ste
phen
son/
Nix
on,
This
spr
eads
heet
dem
onst
rate
s th
e ca
lcul
atio
n of
wor
st-c
ase
head
loss
thro
ugh
the
prop
osed
aer
atio
n pi
ping
sys
tem
Figu
re 4
-1 -
Sat
urat
ion
Wat
er V
apor
Pre
ssur
e,W
ater
vap
or p
ress
ure
(psi
) vs
tem
pera
ture
(°F)
can
P
inle
t =
14.5
3ps
iabe
cal
cula
ted
with
the
follo
win
g fo
rmul
aT
inle
t =
101
fQ
proc
ess
2415
7sc
fmV
P =
a*T
5+�b*
T4+�c*T3
+�d*
T2+�e*T�+�f
RH
Inle
t =
0.41
Qpr
oces
s26
475.
77ic
fmW
here
:T d
isch
arge�=
175
FQ
proc
ess
2017
1.81
acfm
a =
2.27
E-1
1P d
isch
arge
=9.
05ps
igb
=-2
.5E
-10
��=
0.00
022 5
ft2/s
c =
5.08
E-0
7�
=0.
0000
5in
ches
for s
t. st
eel
d =
7.42
E-0
6�
act=
0.10
0669
7lb
/scf
e =
0.00
1485
Vp
act
6.71
6900
7f =
0.01
6274
VP
std
0.33
9020
5V
p in
let
0.97
8097
1
Des
crip
tion
Cum
mul
ativ
e Lo
ssh L
(inH
2O)
h L(p
si)
(1)
Inle
t Filt
er L
oss
30.
1082
3(2
)In
let S
ilenc
er L
oss
1.5
0.05
411
(3)
Loss
acr
oss
diffu
ser
120.
4329
Tota
l Blo
wer
Pip
ing
Inle
t Los
ses
=0.
16ps
i
Min
or L
osse
s (e
st.)
Tota
l Los
ses
Cum
mul
ativ
e Lo
ssD
escr
iptio
nD
iam
(in)
Q (s
cfm
)Q
(icf
m)
Q (a
cfm
)D
iam
(in)
Vel (
fpm
)Le
ngth
(ft)
Re
�/D
f cal
chi
(inH
2O)
h L(in
H2O
)�
Kh L
(inH
2O)
h L(in
H2O
)h L
(psi
)h L
(inH
2O)
h L(p
si)
(1)
16" B
low
er O
utle
t16
6039
.366
18.9
4350
42.9
516
3611
.749
134.
64E
+06
0.00
0003
0.00
91.
0932
320.
0992
675.
25.
6848
095.
7840
750.
2086
615.
7840
750.
2086
61(2
)30
" Air
Pip
ing
3024
157
1323
7.89
2017
1.8
3041
09.3
6715
01.
14E
+08
0.00
0002
0.00
71.
4152
310.
5681
90.
550.
7783
771.
3465
680.
0485
777.
1306
430.
2572
38(3
)18
" Air
Pip
ing
1880
52.4
8825
.258
6723
.94
1838
04.9
710
54.
44E
+07
0.00
0003
0.00
71.
2133
330.
6262
060.
550.
6673
331.
2935
380.
0466
648.
4241
810.
3039
03(4
)14
" Air
Pip
ing
1453
68.2
744
12.6
2944
82.6
214
4193
.232
662.
39E
+07
0.00
0004
0.00
81.
4735
850.
6545
880.
30.
4420
761.
0966
640.
0395
629.
5208
450.
3434
65(5
)12
" Air
Pip
ing
1226
84.1
344
12.6
2922
41.3
112
2853
.727
952.
01E
+07
0.00
0004
0.00
80.
6825
0.52
1569
2.1
1.43
3249
1.95
4818
0.07
052
11.4
7566
0.41
3985
(6)
10" A
ir P
ipin
g/D
iff. H
ead
1013
42.0
722
06.3
1411
20.6
610
2054
.684
202.
54E
+06
0.00
0005
0.01
00.
3538
080.
0866
630.
30.
1061
420.
1928
050.
0069
5511
.668
470.
4209
4(8
)Lo
ss T
hrou
gh D
iffus
er/O
rific
e15
150.
5411
2626
.668
470.
9620
66(9
)D
iffus
er F
oulin
g Lo
ss14
140.
5050
5140
.668
471.
4671
16
Aer
atio
n S
yste
m L
osse
s
Blo
wer
Pip
ing
Inle
t Los
ses
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
Tota
l Blo
wer
Pip
ing
Dis
char
ge L
osse
s =
1.47
psi
Cel
l MS
wam
ee J
ain
Stat
ic P
ress
ure
= 5.
63ps
iC
ell N
Pre
ssur
e V
Cel
l OD
arcy
Wei
sbac
hB
low
er D
isch
arge
Pre
ssur
e R
equi
red
=7.
09ps
i
(1)
16" B
low
er O
utle
t14
" X 3
0" B
end
(2)
30" A
ir P
ipin
g30
" Ben
d, 3
0" x
18"
Red
(3)
18" A
ir P
ipin
g18
" Ben
d, 1
8" x
14"
Red
(4)
14" A
ir P
ipin
g14
" x 1
2" R
ed(5
)12
" Air
Pip
ing
12" B
end,
12"
x 1
0" T
ee(6
)10
" Air
Pip
ing/
Diff
. Hea
d10
" Ben
d(7
)Lo
ss T
hrou
gh D
iffus
erR
ecom
men
ded
per S
anita
ire(8
)D
iffus
er L
oss
w/ A
ge
��
��� ��
� �
�� � �� ��
���
AA
I
SS
S
SA
VPRH
PVP
RHP
TTSCFM
ICFM
**46
046
0*
250
3.3 SYSTEM DESIGN - SYSTEM CURVEThis spreadsheet displays the system curve of the aeration blower piping system. The data is poltted on graphs on the following spreadsheets.
SCFM PSI0 5.63
1000 5.632000 5.643000 5.654000 5.675000 5.696000 5.727000 5.758000 5.799000 5.83
10000 5.8811000 5.9312000 5.9913000 6.0514000 6.1215000 6.1916000 6.2717000 6.3518000 6.4419000 6.5420000 6.6321000 6.74
y�=�2.51E�09x2 +�5.63E+00R²�=�1.00E+00
5.40
5.60
5.80
6.00
6.20
6.40
6.60
6.80
0 5000 10000 15000 20000 25000
Series1
Poly.�(Series1)
251
3.4 SYSTEM DESIGN - BLOWER DESIGNThis spreadsheet details the multiple temperature, pressure, and flow related conditions that are taken into account to correctly size the blowers
Historical Weather Data for West Palm BeachData Source Parameter Value
ASHRAE Extreme (1%) Conditions for WPB
Design Temperature (Wet Bulb) (°F): 80
NOAA Records for West Palm Beach
Maximum Temperature (°F): 101
Resulting Relative Humidity*: 41%
Blower Inlet and Discharge Pressures From 5th Order Curve Fit of Stephenson/Nixon, Ambient Barometric Pressure (psia) 14.696 Figure 4-1 - Saturation Water Vapor Pressure,Blower Inlet Pressure (psia) 14.53 Water vapor pressure (psi) vs temperature (°F) can System Design Pressure Loss (psig): 7.09 be calculated with the following formula:Estimated Discharge Pressure (psia): 21.79 VP = a*T5 +�b*T4 +�c*T3�+�d*T2�+�e*T�+�f
Where:Correct Blower Florate Design Point for Extreme Hot Weather Condition a = 2.27E-11 32°F � T � 140°FParameter Std. Cond. Design b = -2.5E-10Inlet Temperature (°F): 68.0 101.0 c = 5.08E-07Absolute Inlet Temperature (°R): 528 561 d = 7.42E-06Relative Humidity: 36% 41% e = 0.001485Vapor Pressure (psi): 0.3390 0.9781 --------------> f = 0.016274Barometric Pressure (psi): 14.70 14.53Density Correction Factor (ICFM/SCFM): 1.00 1.10 -------------->Maximum Day Air Flow (CFM): 24,157 26,469
Correct Blower Pressure Design Point for Extreme Hot Weather Conditionk-1/k 0.283 0.283Approximate Site Discharge Pressure (psig): 7.09Equivalent Air Pressure (EAP) (psig): 7.87 -------------->
Size Blowers Additional InformationMinimum Mixing Air Flow (SCFM): 4,563Average Annual Air Flow (SCFM): 9,921 10,870 icfmMaximum Month Air Flow (SCFM): 15,679 17,180 icfmMaximum Day Air Flow (SCFM): 24,157 26,469 icfmConversion Factor (ICFM/SCFM): 1.10Number of Blowers: 4
� �� ���
���
���
���
���
�AAI
SSS
S
A
VPRHPVPRHP
TTSCFMICFM
**
460460*
� � 111
11
��
��
�
��
��
��
���
�
�
���
�
��
�
���
����
���
��
kk
kk
BI
DS
S
iS P
PTTPEAP
Number of Blowers: 4Ratio of Large To Small 1.5Small Blower Capacity (ICFM): (1 x) 5,000 4,563 SCFM 23728.7277Large Blower Capacity (ICFM): (3 x) 7,000 6,389 SCFMFirm Blower Capacity (ICFM): 17,000Is Max. Month Requirement met w/ Firm Capacity? NoRequired Blower Turn Down to Meet Minimum Flow: 34.8%Site Barometric Pressure (psia): 14.70Small Blower Rating Point (SCFM) 5,000 @ 7.87 psig 200 HP Large Blower Rating Point (SCFM) 7,000 @ 7.87 psig 300 HP
=IF(C38=2,ROUND(D36/2.5,-2),IF(C38=3,ROUND(D36/3.5,-2),IF(C38=4,ROUND(D36/5.5,-2),IF(C38=5,ROUND(D36/7,-2),0)))
� �� ���
���
���
���
���
�AAI
SSS
S
A
VPRHPVPRHP
TTSCFMICFM
**
460460*
� � 111
11
��
��
�
��
��
��
���
�
�
���
�
��
�
���
����
���
��
kk
kk
BI
DS
S
iS P
PTTPEAP
252
4.0
- CO
ST E
STIM
ATE
- SU
MM
AR
YTh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he c
apita
l cos
t est
imat
e in
spr
eads
heet
s 8.
1 - 8
.7
Item
ECM�No.�1
ECM�No.�2
ECM�No.�3
Commen
ts/Sou
rce
Dem
olition
$30,242
$30,242
$30,242Spreadsheet�8
.1Blow
ers
$535,000
$748,750
$748,750
Spreadsheet�8
.2Diffusers
$445,500
$445,500
$445,500
Spreadsheet�8
.3Structural���Blow
er�Building
$73,104
$73,104
$73,104Spreadsheet�8
.4Mechanical���Piping
$290,786
$290,786
$290,786
Spreadsheet�8
.5Instrumen
tatio
n$69,000
$69,000
$298,875
Spreadsheet�8
.6Electrical
$187,213
$187,213
$220,924
Spreadsheet�8
.7
SubT
otal�1
$1,630,845
$1,844,595
$2,108,182
Contractor�OH&P
$326,169
$368,919
$421,636
20%���Interpolated
�from
�01�31�13.80
Subtotal�2
$1,957,015
$2,213,515
$2,529,818
Performance�Bon
d$19,570
$22,135
$25,2981%
Insurance
$9,785
$11,068
$12,6490.5%
���Highe
r�en
d�of�01�31�13.30
Perm
its$19,570
$22,135
$25,2981%
���Mid�range�"rule�of�thu
mb",�01�41�26.50
Subtotal�3
$2,005,940
$2,268,852
$2,593,063
Contingency
$200,594
$226,885
$259,306
10%���01�21�16.50���P
relim
inary�Working�Drawing�Stage
Engine
ering�Fee�(design�and�
constructio
n�administration�
based�on
�sub
total�1)
$244,627
$276,689
$316,227
15%���Ba
sed�on
�typical
Grand
�Total
$2,451,161
$2,772,427
$3,168,597
AACE
�Class�4�Low
�Ran
ge�(�20%)
$1,960,000
$2,220,000
$2,530,000
AACE
�Class�4�Hi�R
ange�(+
30%)
$3,190,000
$3,600,000
$4,120,000
253
4.1
- CO
ST E
STIM
ATE
- D
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9EA
$500.00
$349.50
$3,1
461
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erator�W
eight�X
�94.5TO
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$01
26�05�05.25�1070
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olish�10
0�HP�Motor�and
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9EA
$218.00
$152.38
$1,3
711
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�cable�f�M
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26�05�05.10�010 0
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$1.13
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$1.37
$1,9
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1400
LF$0.65
$0.45
$636
126�05�05.10�029 0
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2800
LF$0.69
$0.48
$1,3
501
26�05�05.10�187 0
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2800
LF$0.12
$0.08
$235
1
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ECM�No.�1
$30,242
ECM�No.�2
$30,242
ECM�No.�3
$30,242
254
4.2
- CO
ST E
STIM
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- B
LOW
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DIV
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N N
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$159,00 0
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$198,750
$596
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$122,00 0
$30,500
$152,500
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2
$748,750
COMPA
RABLE�MULTI�S
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NTR
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$110,000
$27,500
$137,500
$412
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1(2)�2
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1EA
$98,000
$24,500
$122,500
$122
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1
$535,000
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$535,000
ECM�No.�2
$748,750
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$748,750
HP
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HP
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get $
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50$5
6,00
0E
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250
$180
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$102
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$75,
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$165
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250
$168
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250
$188
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Roh
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20,0
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300
$175
,000
EP
A15
0$1
34,0
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300
$142
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EP
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20,0
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PA
300
$119
,000
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60,0
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300
$119
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Roh
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300
$143
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Roh
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0$9
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. al
300
$156
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Roh
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0R
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300
$208
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$209
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400
$275
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400
$132
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$325
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25,0
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MULTI_STAGE�CE
NTR
IFUGAL�CO
STS
HP
Bud
get $
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ceA
vera
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$98,000H&S
$98,000
250
$90,000H&S
$90,000
300
$153,000
H&S
300
$72,000H&S
300
$104,00 0
H&S
350
$110,00 0
H&S
$110,000
400
$135,000
H&S
400
$88,000H&S
500
$245,00 0
H&S
500
$170,00 0
H&S
500
$190,00 0
H&S
$110,000
$112,000
$202,000
$170
,000
$104
,000
$127
,000
$159
,000
$122
,000
$202
,000
$79,
000
255
4.3
- CO
ST E
STIM
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- D
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DIV
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N N
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Mat
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$445
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ECM�No.�2
$445
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$445
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256
4.4
- CO
ST E
STIM
ATE
- ST
RU
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LWPB
�City
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$86
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103
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$610
$60
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$133
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$129
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�30�53
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50Equipm
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$61
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$6$6
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�23�23
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$48
$290
$580
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$1,675
$490
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$31
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$568
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2260
SF$0
$0$0
$665
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$73,104
257
4.5
- CO
ST E
STIM
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- M
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L PI
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$26,77
51
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6315
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78.75
$24,88
51
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�Felker�Bro14
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100
$15,50
01
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�Felker�Bro18
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$10,20
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�Felker�Bro20
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113
28.25
141.25
$9,323
12/08
�Felker�Bro24
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44.5
222.5
$8,233
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$41,62
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1000
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1000
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1000
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$2,000
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1000
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"�x�24
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1000
1000
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$2,000
124
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1000
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120
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"�Cross
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1000
1000
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$2,000
114
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1000
1000
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$2,000
118
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1000
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$2,000
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1000
1000
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$2,000
124
"�x�20
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1000
1000
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$2,000
120
"�x�14
"�Re
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1000
1000
2000
$2,000
118
"�x�14
"�Re
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1000
1000
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$2,000
114
"�x�12
"�Re
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1000
1000
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$2,000
114
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1000
1000
2000
$2,000
112
"�x�12
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1000
1000
2000
$2,000
112
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"�Tee
9EA
1000
1000
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$18,00
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01
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1500
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$1,875
124
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1000
250
1250
$1,250
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0,68
81
22�05�29
.10�017H
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298
14.3
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125
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$42,50
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$290
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$290
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258
4.6
- CO
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STIM
ATE
- IN
STR
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TIO
N
DIV
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N N
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$20,625.00
3
Hach�List�Price
Hach�SC�100
�Con
troller,�((3(�2�probe
�controllers,�(3)�1�probe
�con
trollers)
61350
337.5
1687.5
$10,125.00
3Hach�List�Price
LDO�Probe
91510
377.5
1887.5
$16,987.50
3Hach�List�Price
115�V�Air�Blast�Cleaning�System
9800
200
1000
$9,000.00
3Hach�List�Price
Pole�M
ount�Kit
9380
95475
$4,275.00
3
Mod
ulating�BF
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96800
1700
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$76,500.00
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9/16/10
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surge�supp
ressor,�toggle�sw
itch,�
wiring
92200
550
2750
$24,750.00
3SS�Unistrut�M
ount
950
12.5
62.5
$562.50
3
Differen
tial�Pressure�Indicators�(Flow�M
eter)
5/09�PFS�Quo
te14"�Ve
nturi�Flow�Elemen
t9
3300
825
4125
$37,125.00
310/08�PFS�Quo
te`
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g�Transm
itter
91800
450
2250
$20,250.00
3CC
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9/16/10
Alum�Pipe�Stand�Mou
nt�w/�sunshield
9650
162.5
812.5
$7,312.50
3Amerispo
nse.com,�9/19/10
4�20�m
a�Surge�Supp
ressor
18105
26.25
131.25
$2,362.50
3
Programming�Co
sts
Job�of�sim
ilar�scop
e/scale,�1/11
Programmab
le�Logic�Con
troller
1LS
50000
50000
$25,000.00
1/3
Job�of�sim
ilar�scop
e/scale,�1/11
Software
1LS
3000
3000
$1,500
.00
1/3
Job�of�sim
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10000
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$5,000.00
1/3
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Programming�and�Trou
blesho
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1LS
1500
015
000
$7,500
.00
1/3
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1000
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$5,000
.00
1/3
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ming�and�Re
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5000
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$25,00
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$69,000.00
ECM�No.�2
$69,000.00
ECM�No.�3
$298,875.00
259
4.7
- CO
ST E
STIM
ATE
- EL
ECTR
ICA
LWPB
�City
WPB
�City
Mat
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1D5020�145�0240M
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$700
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$890
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D5025�120�116
014�Re
ceptacles/2,00
0�sf
2117
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$1.95
$2.07
$4,387
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$0.10
$0.35
$0.37
$786
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1D5020�208�0680Lighting,�Fluroescent�Fixtures
2117
SF$2
.33
$4.88
$6.10
$12,90
7.37
126
�24�16
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Pane
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$735
.00
$605
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26�05�19
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$66.00
$98.00
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$1.66
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$10.90
$35.50
$38.42
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$10.90
$35.50
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$691
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326
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$2.14
$0.87
$2.78
$555
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126
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$8.65
$32.50
$33.87
$135
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$2.14
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326
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$8.65
$32.50
$33.87
$304
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326
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$0.44
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326
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.34
326
�05�26
.80�033#12
�GND
1050
LF$0
.11
$0.30
$0.34
$359
.32
326
�05�19
.35�163��Terminate�#12
18EA
$0.58
$7.85
$6.70
$120
.60
326
�05�23
.10�0308�#14
400LF
$0.67
$0.74
$1.24
$494
.08
126
�05�26
.80�032#14
�GND
800LF
$0.07
$0.28
$0.29
$229
.88
126
�05�19
.35�162��Terminate�#14
32EA
$0.43
$6.55
$5.54
$177
.20
126
�05�26
.80�032#14
�GND
1575
LF$0
.07
$0.28
$0.29
$452
.58
326
�05�19
.35�162��Terminate�#14
27EA
$0.43
$6.55
$5.54
$149
.51
3Co
nduit
26�05�33
.05�0701"�Co
nduit,�Alum
800LF
$4.30
$4.90
$8.05
$6,436
.16
126
�05�33
.05�0701"�Co
nduit,�Alum
3150
LF$4
.30
$4.90
$8.05
$25,34
2.38
326
�05�33
.05�1103"�Co
nduit,�Alum
700LF
$22.50
$8.70
$28.87
$20,20
7.04
133
�77�19
.17�080Con
crete�Handh
oles
1EA
$510
.00
$582
.50
$955
.24
$955
.24
133
�17�19
.17�700D
uctbank�and�Co
nduit,�10��@
100LF
$171
.25
$39.25
$198
.65
$19,86
5.05
133
�71�19
.17�783Con
crete�(15�CY
/100
�LF)
100LF
$1.61
$0.72
$2.14
$214
.17
133
�71�19
.17�786Reinforcing�(1
0�Lb/LF)
100LF
$4.00
$3.40
$6.58
$657
.94
1Exterior�Groun
ding/Lightning�Protection
26�05�26
.80�013G
roun
ding�Rod
s,�cop
per
8EA
$92.00
$98.00
$166
.79
$1,334
.32
126
�05�26
.80�1004/0�Groun
ding
320LF
$3.85
$1.38
$4.85
$1,553
.48
126
�41�13
.13�050A
ir�Terminals
10EA
$24.50
$49.00
$62.30
$623
.04
126
�41�13
.13�250A
lum�Cable
270LF
$0.85
$1.40
$1.93
$520
.36
126
�41�13
.13�300A
rrestor
2EA
$78.50
$49.00
$115
.28
$230
.56
1
ECM�No.�1
$187
,213
.28
ECM�No.�2
$187
,213
.28
ECM�No.�3
$220
,924
.44
260
5.0
- O&
M C
OST
S
Plant�Labor�Rate
Discoun
t�Rate�(in
terest)
CPI
Real�Rate
Planning�
Period
�(years)
36.45
0.047
0.025
0.022
20
Equipm
ent
O&M�Item
Cost
Amou
nt�
Unit
Ann
ual
NPV
ECM
Source
Diffusers
Replace�Mem
branes
$9.04
1EA
$1$18
1,2,3
Sanitaire/Lesourdsville,�5/m
in�per�diffuser,�$6�replacem
ent�cost,�7�10�year�inter v
Turbo�Blow
ers
Replace�Filte
rs,�Inspe
ctio
$2,500
4EA
$10,000
$160,402
2,3
Rohrbacher�et.�al
LDO�Probe
sRe
place�Sensor�Caps
$140
9EA
$1,26 0
$20,211
3Article:�"DO"ing�m
ore�with
�Less,�List�P
rice:�H
ach
Diffusers
Clean�Mem
branes
$36
60HR
$2,18 7
$35,080
1,2,3
Rosso,�Econo
mic�Im
plications�of�Fine�Po
re�Diffuser�Aging
Multi�Stage�Blow
ers
Typical�O
&M�based
�on�1
$1,50 0
4$6,000
$96,241
11.5%
�Capita
l�Cost,�per�Roh
rbache
r�et.�al
Equipm
ent
O&M�Item
Cost
Amou
nt�
Ann
ual
NPV
ECM
Source
Manual�D
OCo
llect�DO�M
anually
�$55
365
�$19,95 6
�$320,104
330�M
ins�Pe
r�Ba
sin,�3�times�per�day
Mech�Diffuser�M
otors
Service�Motors
�$292
9�$2,624
�$42,096
1,2,3
Need�to�ask�Boca�Ra
ton
SUMMAR Y
Ann
ual
NPV
ECM��N
o.�1�O&M
$5,56 4
$89,243
ECM��N
o.�2�O&M
$9,56 4
$153,404
ECM��N
o.�3�O&M
�$9,133
�$146,489
Equipm
ent
Useful�Life
Remaining�Rep
lacemeAmou
nt�
Total
NPV
Source
100�HP�Electric�M
otors
201000
�6025
9�$54,22 5
$01,2,3
RS�M
eans�26�71�13.10�5260�+�26�71�13.20�2100
100�HP�Motor�Starters
2010
�$3,150
9�$28,350
�$22,806
1,2,3
RS�M
eans�26�24�19.40�0500
Replace�Aerators
2010
�$100,000
9�$1,258,146
�$1,012,096
1,2,3
6/17/11�Quo
te�f/�TSC�Ja
cobs
SUMMARY
NPV
ECM��N
o.�1
�$1,034,902
ECM��N
o.�2
�$1,034,902
ECM��N
o.�3
�$1,034,902
O&M�Costs
O&M�No�Longer�Neccesary
Equipm
ent�R
eplacemen
t�No�Longer�Neccesary
261
5.1
- O&
M C
OST
S - R
EPLA
CE
AER
ATO
RS
WPB
�City
WPB
�City
SOURC
EDESCR
IPTION
QUANTIT Y
UNIT
Material
Labo
rEq
uip
Total�U
nit
TOTA
LEC
M�No.
Mat�In
dexL
abor
Inde
x0.96
40.69
9
Kelly�Tractor�Quo
teCR
ANE�RE
NTA
L���4
0�TO
N�CAPA
CITY
4MO
$10,00
0.00
$40,00
0Re
move�Mech�Aerator
9EA
$500
.00
$349
.50
$3,146
Mechanical�A
erator�W
eight�X
�94.5TO
NS
$0New
�Mechanical�A
erators
9EA
1000
0035
000
1350
00$1
,215
,000
Sum
ECM�No.�1
$1,258
,145
.50
262
6.0 LIFE-CYCLE COST ANALYSIS INPUTS
CurrentCost per
kwH
Bond Rate CPI Inflation
Real Rate (interest)
EnergyInflation
PlanningPeriod(years)
CurrentHP
0.07 0.047 0.025 0.022 0.00083 20 831.1
PowerFactor
If no Amp draws,
assumed% of
Nameplate
AvgBasins in Operation
0.84 0.85 3
Aerator # Nameplate HP
Avg Low SpeedAmps
Avg High Speed
Amps (1)
Months in low setting
Avg Amps Avg KW Avg Operating
HP#1 100 59 109.00 12 59 41.2 55.2#2 100 60.67 112.67 5 91 63.6 85.2#3 125 169.67 170 118.5 158.8#4 100 59 111 12 59 41.2 55.2#5 100 59.67 111.67 4 94 65.9 88.3#6 125 145.33 145 101.5 136.0#7 100 71.33 104 1 101 70.7 94.8#8 100 65.67 91 1 89 62.1 83.2#9 125 79.33 79 55.4 74.3
Total 888 620.0 831.1(1)�Data�based�on�amp�draw�readings�provided�by�City�of�Plantation�for�11/29/11
Blower # Nameplate HP
Factor(2) Adjusted HP
#1#2#3
125 100 56 Operating�HP�/�Nameplate�HP123 100 59 0.98
Zone�1�Avg Zone�2�Avg Zone�3�Avg123.0 85.6 68.4
263
6.1.
1 LI
FE-C
YCLE
CO
ST A
NA
LYSI
STh
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
IN
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 1
.5 m
g/L
540
65%
$246
,886
($3,
989,
085)
1,50
5,50
2$������
6.34
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L59
572
%$2
72,3
09($
4,39
9,85
9)1,50
5,50
2$������
5.70
Com
plet
e N
Ox
442
53%
$202
,091
($3,
265,
307)
1,50
5,50
2$������
7.91
Cur
rent
Tre
atm
ent -
1.5
mg/
L40
5%$1
8,51
5($
299,
156)
385,42
7$���������
30.0
8C
urre
nt T
reat
men
t - 3
.0 m
g/L
-4-1
%($
2,02
0)$3
2,63
538
5,42
7$���������
Com
plet
e N
Ox
547%
$24,
736
($39
9,68
1)38
5,42
7$���������
18.9
6C
urre
nt T
reat
men
t - 1
.5 m
g/L
00%
$0$0
96,277
$������������
28.8
4C
urre
nt T
reat
men
t - 1
.5 m
g/L
648%
$29,
422
($47
5,39
1)96
,277
$������������
9.16
Com
plet
e N
Ox
8410
%$3
8,57
1($
623,
217)
96,277
$������������
7.57
Cur
rent
Tre
atm
ent -
1.5
mg/
L58
070
%$2
65,4
01($
4,28
8,24
1)1,
987,
205
$
8.
59C
urre
nt T
reat
men
t - 1
.5 m
g/L
655
79%
$299
,711
($4,
842,
614)
1,98
7,20
5$
7.55
Com
plet
e N
Ox
580
70%
$265
,398
($4,
288,
205)
1,98
7,20
5$
8.59
* C
urre
nt tr
eatm
ent i
ndic
ates
ene
rgy
impr
ovem
ent r
ealiz
ed b
y tre
atin
g to
par
tial n
itrifi
catio
n at
0.5
mg/
L, w
hich
is th
e pl
ants
cur
rent
leve
l of t
reat
men
t
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
129
165
%$2
46,8
86($
3,98
9,08
5)5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$2,451,161
1,505,502
$��
6.34
Cur
rent
Tre
atm
ent -
3.0
mg/
L83
123
672
%$2
72,3
09($
4,39
9,85
9)5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$2,451,161
1,505,502
$��
5.70
Com
plet
e N
Ox
831
389
53%
$202
,091
($3,
265,
307)
5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$2,451,161
1,505,502
$��
7.91
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
125
170
%$2
65,4
01($
4,28
8,24
1)9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$2,772,427
1,890,929
$��
7.41
Cur
rent
Tre
atm
ent -
3.0
mg/
L83
124
071
%$2
70,2
89($
4,36
7,22
4)9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$2,772,427
1,890,929
$��
7.26
Com
plet
eN
Ox
831
335
60%
$226
827
($3
664
988)
956
4$
15340
4$
(103
490
2)$
$2772427
1890929
$8
86
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
Tota
l (C
umul
ativ
e)
Com
plet
eN
Ox
831
335
60%
$226
,827
($3,
664,
988)
9,56
4$��������������
153,40
4$������������
(1,034,902
)$��������
$2,772,427
1,890,929
$��
8.86
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
125
170
%$2
65,4
01($
4,28
8,24
1)(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$3,168,597
1,987,205
$��
8.59
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
117
679
%$2
99,7
11($
4,84
2,61
4)(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$3,168,597
1,987,205
$��
7.55
Com
plet
e N
Ox
831
251
70%
$265
,398
($4,
288,
205)
(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$3,168,597
1,987,205
$��
8.59
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
mai
ntai
n D
O a
t ave
rage
of 3
to 4
mg/
L. T
he a
ctua
l val
ue u
sed
can
be b
ased
on
aver
age
DO
mea
sure
men
ts a
t oth
er c
ount
y pl
ants
.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
62%
effi
cien
cy w
/ Mul
ti-S
tage
cen
trifu
gal,
then
72%
with
turb
os.
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y us
ing
diur
nal c
urve
vs.
pre
ssur
e se
tpoi
nt.
3. A
utom
atic
DO
C
ontro
l (1.
5 m
g/L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
1. F
ine
Bub
ble
Diff
user
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
264
6.1.
2 LI
FE-C
YCLE
CO
ST A
NA
LYSI
S (L
OW
RA
NG
E)Th
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
IN
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 1
.5 m
g/L
540
65%
$246
,886
($3,
989,
085)
1,01
4,34
1$������
4.04
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L59
572
%$2
72,3
09($
4,39
9,85
9)1,01
4,34
1$������
3.64
Com
plet
e N
Ox
442
53%
$202
,091
($3,
265,
307)
1,01
4,34
1$������
5.01
Cur
rent
Tre
atm
ent -
1.5
mg/
L40
5%$1
8,51
5($
299,
156)
324,16
1$���������
22.7
1C
urre
nt T
reat
men
t - 3
.0 m
g/L
-4-1
%($
2,02
0)$3
2,63
532
4,16
1$���������
Com
plet
e N
Ox
547%
$24,
736
($39
9,68
1)32
4,16
1$���������
14.7
2C
urre
nt T
reat
men
t - 1
.5 m
g/L
00%
$0$0
10,107
$������������
20.8
5C
urre
nt T
reat
men
t - 1
.5 m
g/L
648%
$29,
422
($47
5,39
1)10
,107
$������������
7.01
Com
plet
e N
Ox
8410
%$3
8,57
1($
623,
217)
10,107
$������������
5.82
Cur
rent
Tre
atm
ent -
1.5
mg/
L58
070
%$2
65,4
01($
4,28
8,24
1)1,
348,
608
$
5.
85C
urre
nt T
reat
men
t - 1
.5 m
g/L
655
79%
$299
,711
($4,
842,
614)
1,34
8,60
8$
5.17
Com
plet
e N
Ox
580
70%
$265
,398
($4,
288,
205)
1,34
8,60
8$
5.85
* C
urre
nt tr
eatm
ent i
ndic
ates
ene
rgy
impr
ovem
ent r
ealiz
ed b
y tre
atin
g to
par
tial n
itrifi
catio
n at
0.5
mg/
L, w
hich
is th
e pl
ants
cur
rent
leve
l of t
reat
men
t
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
129
165
%$2
46,8
86($
3,98
9,08
5)5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$1,960,000
1,014,341
$��
4.04
Cur
rent
Tre
atm
ent -
3.0
mg/
L83
123
672
%$2
72,3
09($
4,39
9,85
9)5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$1,960,000
1,014,341
$��
3.64
Com
plet
e N
Ox
831
389
53%
$202
,091
($3,
265,
307)
5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$1,960,000
1,014,341
$��
5.01
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
125
170
%$2
65,4
01($
4,28
8,24
1)9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$2,220,000
1,338,502
$��
4.93
Cur
rent
Tre
atm
ent -
3.0
mg/
L83
124
071
%$2
70,2
89($
4,36
7,22
4)9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$2,220,000
1,338,502
$��
4.83
Com
plet
eN
Ox
831
335
60%
$226
827
($3
664
988)
956
4$
15340
4$
(103
490
2)$
$2220000
1338502
$5
86
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x83
133
560
%$2
26,8
27($
3,66
4,98
8)9,56
4$��������������
153,40
4$������������
(1,034,902
)$��������
$2,220,000
1,338,502
$��
5.86
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
125
170
%$2
65,4
01($
4,28
8,24
1)(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$2,530,000
1,348,608
$��
5.85
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
117
679
%$2
99,7
11($
4,84
2,61
4)(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$2,530,000
1,348,608
$��
5.17
Com
plet
e N
Ox
831
251
70%
$265
,398
($4,
288,
205)
(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$2,530,000
1,348,608
$��
5.85
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
mai
ntai
n D
O a
t ave
rage
of 3
to 4
mg/
L. T
he a
ctua
l val
ue u
sed
can
be b
ased
on
aver
age
DO
mea
sure
men
ts a
t oth
er c
ount
y pl
ants
.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
62%
effi
cien
cy w
/ Mul
ti-S
tage
cen
trifu
gal,
then
72%
with
turb
os.
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y us
ing
diur
nal c
urve
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (1.
5 m
g/L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
265
6.1.
3 LI
FE-C
YCLE
CO
ST A
NA
LYSI
S (H
IGH
RA
NG
E)Th
is s
prea
dshe
et s
umm
ariz
es th
e re
sults
of t
he li
fe c
ycle
cos
t ana
lyse
s.
TAB
LE 1
- IN
CR
EMEN
TAL
GA
IN
Tech
nolo
gyLe
vel o
f Tre
atm
ent
HP
R
educ
tion
% E
ff.
Gai
nA
nn. E
nerg
y C
ost S
avin
gsE
nerg
yS
avin
gs N
PV
Cap
ital a
nd
O&
M N
PV
Pay
back
Cur
rent
Cos
t per
kw
HB
ond
Rat
eC
PI I
nfla
tion
Rea
l Rat
e (in
tere
st)
Ene
rgy
Infla
tion
Pla
nnin
gP
erio
d(y
ears
)C
urre
nt T
reat
men
t - 1
.5 m
g/L
540
65%
$246
,886
($3,
989,
085)
2,24
4,34
1$������
10.01
0.07
0.04
70.
025
0.02
20.
0008
320
Cur
rent
Tre
atm
ent -
3.0
mg/
L59
572
%$2
72,3
09($
4,39
9,85
9)2,24
4,34
1$������
8.96
Com
plet
e N
Ox
442
53%
$202
,091
($3,
265,
307)
2,24
4,34
1$������
12.62
Cur
rent
Tre
atm
ent -
1.5
mg/
L40
5%$1
8,51
5($
299,
156)
474,16
1$���������
43.2
5C
urre
nt T
reat
men
t - 3
.0 m
g/L
-4-1
%($
2,02
0)$3
2,63
547
4,16
1$���������
Com
plet
e N
Ox
547%
$24,
736
($39
9,68
1)47
4,16
1$���������
25.8
5C
urre
nt T
reat
men
t - 1
.5 m
g/L
00%
$0$0
220,10
7$���������
43.4
9C
urre
nt T
reat
men
t - 1
.5 m
g/L
648%
$29,
422
($47
5,39
1)22
0,10
7$���������
12.4
4C
ompl
ete
NO
x84
10%
$38,
571
($62
3,21
7)22
0,10
7$���������
10.2
1C
urre
nt T
reat
men
t - 1
.5 m
g/L
580
70%
$265
,401
($4,
288,
241)
2,93
8,60
8$
12.9
8C
urre
nt T
reat
men
t - 1
.5 m
g/L
655
79%
$299
,711
($4,
842,
614)
2,93
8,60
8$
11.3
5C
ompl
ete
NO
x58
070
%$2
65,3
98($
4,28
8,20
5)2,
938,
608
$
12
.98
* C
urre
nt tr
eatm
ent i
ndic
ates
ene
rgy
impr
ovem
ent r
ealiz
ed b
y tre
atin
g to
par
tial n
itrifi
catio
n at
0.5
mg/
L, w
hich
is th
e pl
ants
cur
rent
leve
l of t
reat
men
t
TAB
LE 2
- C
UM
ULA
TIVE
GA
IN (e
ach
proc
eedi
ng im
prov
emen
t is
accu
mul
ativ
e of
the
prev
ious
list
ed)
Tech
nolo
gyLe
vel o
f Tre
atm
ent
Cur
rent
HP
Pro
pose
d H
PA
nnua
l Sav
ings
%
Ann
ual S
avin
gs
$E
nerg
y S
avin
gs
NP
VA
nnua
l Cha
nge
O&
MC
hang
e O
&M
N
PV
Fore
gone
Cap
ital
Rep
lace
men
tC
apita
l Cos
t C
apita
l and
O
&M
NP
VP
ayba
ck
Cur
rent
Tre
atm
ent -
1.5
mg/
L83
129
165
%$2
46,8
86($
3,98
9,08
5)5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$3,190,000
2,244,341
$��
10.0
1C
urre
nt T
reat
men
t - 3
.0 m
g/L
831
236
72%
$272
,309
($4,
399,
859)
5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$3,190,000
2,244,341
$��
8.96
Com
plet
e N
Ox
831
389
53%
$202
,091
($3,
265,
307)
5,56
4$��������������
89,243
$��������������
(1,034
,902
)$��������
$3,190,000
2,244,341
$��
12.6
2C
urre
nt T
reat
men
t - 1
.5 m
g/L
831
251
70%
$265
,401
($4,
288,
241)
9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$3,600,000
2,718,502
$��
11.4
0C
urre
nt T
reat
men
t - 3
.0 m
g/L
831
240
71%
$270
,289
($4,
367,
224)
9,56
4$��������������
153,40
4$������������
(1,034
,902
)$��������
$3,600,000
2,718,502
$��
11.1
6C
ompl
ete
NO
x83
133
560
%$2
2682
7($
366
498
8)956
4$
15340
4$
(103
490
2)$
$3600000
2718502
$13
74
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.
5 m
g/L
Tota
l (C
umul
ativ
e)
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
sC
ompl
ete
NO
x83
133
560
%$2
26,8
27($
3,66
4,98
8)9,56
4$��������������
153,40
4$������������
(1,034,902
)$��������
$3,600,000
2,718,502
$��
13.7
4C
urre
nt T
reat
men
t - 1
.5 m
g/L
831
251
70%
$265
,401
($4,
288,
241)
(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$4,120,000
2,938,608
$��
12.9
8C
urre
nt T
reat
men
t - 1
.5 m
g/L
831
176
79%
$299
,711
($4,
842,
614)
(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$4,120,000
2,938,608
$��
11.3
5C
ompl
ete
NO
x83
125
170
%$2
65,3
98($
4,28
8,20
5)(9,133
)$�������������
(146
,489
)$�����������
(1,034
,902
)$��������
$4,120,000
2,938,608
$��
12.9
8
Des
crip
tion
of A
ssum
ptio
ns T
echn
olog
ies
Est
imat
e fin
e bu
bble
effi
cien
cy g
ain
assu
min
g pl
ant o
pera
tors
will
mai
ntai
n D
O a
t ave
rage
of 3
to 4
mg/
L. T
he a
ctua
l val
ue u
sed
can
be b
ased
on
aver
age
DO
mea
sure
men
ts a
t oth
er c
ount
y pl
ants
.
2. T
urbo
Blo
wer
sE
stim
ate
turb
o bl
ower
effi
cien
cy g
ain
by a
ssum
ing
62%
effi
cien
cy w
/ Mul
ti-S
tage
cen
trifu
gal,
then
72%
with
turb
os.
at 3
mg/
L av
erag
e D
O.
Est
imat
e au
to D
O c
ontro
l effi
cien
cy g
ain
by a
ssum
ing
1.5
mg/
L.
Est
imat
e M
OV
effi
cien
cy b
y us
ing
diur
nal c
urve
vs.
pre
ssur
e se
tpoi
nt.
3. A
uto
DO
Con
trol -
1.
5 m
g/L
1. F
ine
Bub
ble
Diff
user
s
3. A
utom
atic
DO
C
ontro
l (1.
5 m
g/L)
4.M
ostO
pen
Val
veB
low
er C
ontro
l vs/
P
ress
ure
Set
poin
t
266
6.2
LIFE
-CYC
LE C
OST
AN
ALY
SIS
SUM
MA
RY
Tech
nolo
gyLe
vel o
f Tre
atm
ent
% E
ff.
Gai
nA
vg. D
aily
E
nerg
y S
avin
gs
(kw
H)
Ann
. Ene
rgy
Cos
t Sav
ings
($
)
Pay
back
(Low
Est
) (Y
ears
)
Pay
back
(Med
ian
Est
)(Y
ears
)
Pay
back
(Hig
h E
st)
(Yea
rs)
Cur
rent
Tre
atm
ent -
1.5
mg/
L D
O65
%96
63$2
46,886
46
10P
art.
Nitr
ifica
tion
- 3.0
mg/
L D
O72
%10
658
$272
,309
46
9C
ompl
ete
Nitr
ifica
tion
53%
7910
$202
,091
58
13C
urre
nt T
reat
men
t - 1
.5 m
g/L
DO
5%72
5$1
8,51
523
3043
Par
t. N
itrifi
catio
n - 3
.0 m
g/L
DO
-1%
-79
-$2,
020
Com
plet
e N
itrifi
catio
n7%
968
$24,
736
1519
26
Cur
rent
Tre
atm
ent -
1.5
mg/
L D
O0%
0$0
2129
43
Par
t. N
itrifi
catio
n - 1
.5 m
g/L
DO
8%11
52$2
9,42
27
912
Com
plet
e N
itrifi
catio
n10
%15
10$3
8,57
16
810
Cur
rent
Tre
atm
ent -
1.5
mg/
L D
O70
%10
387
$265
,401
69
13Pa
rt. N
itrifi
catio
n - 1
.5 m
g/L
DO
79%
1173
0$2
99,7
115
811
Com
plet
e N
itrifi
catio
n70
%10
387
$265
,398
69
13
0.43
1. F
ine
Bub
ble
Diff
user
s
2. T
urbo
Blo
wer
s
3. A
uto
DO
Con
trol -
1.5
mg/
L
Tota
l (C
umul
ativ
e)
267
268
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