EPA-430/9-75-002
JULY 1975
TECHNICAL REPORT
A Guide to the Selection of
COST-EFFECTIVE WASTEWATER
TREATMENT SYSTEMS
I
55
\
01
C3
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Water Program Operations
Washington, D. C. 20460
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JIPA Review Notice
This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not sienify that the
contents necessarily reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or commercial pro-
ducts constitute endorsement or recommendation for use.
NOTE
Methods of estimating costs and evaluating
the cost-effectiveness of land-application
systems are being developed in a separate
document, entitled, Technical Report, Costs
of Wastewater Treatment by Land Application,
No. EPA 430/9-75-003, which will become
available later in 1975.
US EPA - AWBERC LIBRARY
30701 100507125
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EPA-430/9-75-002
July 1975
A GUIDE TO THE SELECTION OF
COST-EFFECTIVE WASTEWATER TREATMENT SYSTEMS
by
Robert H. Van Note
Paul V. Hebert
Ramesh M. Patel
Craig Chupek
Lester Feldman
CONTRACT 68-01-0973
Revised by Order Number 68-01-1276
Project Officer
Gary F. Otakie
Municipal Construction Division
Office of Water Program Operations
U.S. Environmental Protection Agency
Prepared for
OFFICE OF WATER PROGRAMS OPERATIONS
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
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THIS PAGE INTENTIONALLY
BLANK
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FOREWORD
U.S. Environmental Protection Agency
Office of Water Program Operations
TECHNICAL REPORT
A GUIDE TO THE SELECTION OF COST-EFFECTIVE
WASTEWATER TREATMENT SYSTEMS
In response to the Federal Water Pollution Control Act Amend-
ments of 1972 (PL 92-500) this country has undertaken an unprece-
dented building program for new and improved wastewater treatment
works. It is incumbent upon the EPA and all other government
entities to ensure that the funds authorized for this enormous under-
taking be justifiably expended. Accordingly the Act requires that all
construction grant applicants perform a cost-effective analysis to
determine the most cost-effective wastewater management alternative.
Publication of the Cost-Effectiveness Analysis Guidelines
(APPENDIX C of the Report) set forth the procedures for making
a cost-effective analysis. This Technical Report provides technical
information including wastewater treatment costs and examples of
how to use the cost data in performing a cost-effective analysis to
further assist the construction grant applicant. It is emphasized that
the Report presents information only and does not contain mandatory
requirements. The data provides a guide for planners, engineers
and decision makers at all levels of government to evaluate the cost-
effectiveiiess of alternative wastewater treatment methods.
This publication is not intended as a design manual but as an
effective means for making preliminary cost comparisons of waste-
water treatment alternatives based upon the assumptions set forth in
the Report. These assumptions may not be valid in certain cases thus
limiting the Report's applicability.
It is the intention of the Environmental Protection Agency to revise
and update this Technical Report as more technical information becomes
available. The most valuable source of information for revisions
will be the actual experiences of those using the Report. All users
are encouraged to submit such information to the Director of the
Municipal Construction Division (WH-447), Office of Water Program
Operations, Environmental Protection Agency, Washington, D. C.
20460.
Tames L". Ag"ee~
Ssistant Administrator
for Water and Hazardous Materials
III
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THIS PAGE INTENTIONALLY
BLANK
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Abstract
Flow sheets describing various unit processes associated with wastewater
treatment and sludge handling are presented. Curves depicting total, O & M
and amortized capital cost in cents per thousand gallons influent wastewater
are shown for plant capacities ranging from 1-100 MGD. The unit processes
described, for which cost data were developed, include conventional and
advanced wastewater treatment units as well as most sludge handling and
processing units. Diagrams are presented which show logical combinations
of the unit processes to form complete wastewater treatment systems capa-
ble of achieving various levels of effluent quality.
From these diagrams, alternative wastewater treatment systems capable
of achieving the same effluent quality can be selected, and costs of the
systems can be determined by referring to the unit process cost curves.
The data provide a guide for planners, engineers, and decision makers at
all levels of government to evaluate cost-effectiveness of alternative waste-
water treatment proposals.
Appendices have been prepared to enable the users of this guide to obtain cost-
effective information when assumptions other than those used here prevail.
In Appendix A, word descriptions of various unit processes associated with
wastewater treatment and sludge handling are presented. In Appendix B,
equations depicting capital, fixed O&M and flow variable O&M costs in cents
per thousand gallons influent wastewater are shown for plant capacities rang-
ing from 1 to 100 MGD. From these equations, the cost of a wastewater treat-
ment system can be determined by summing costs associated with each unit
process in the treatment system.
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This report was originally submitted in fulfillment of Contract
Number 68-01-0973, and is now resubmitted revised by Order Number
68-01-1276 under the sponsorship of the U.S. Environmental Protection
Agency.
ACKNOWLEDGEMENT
This report was prepared by Bechtel Incorporated, Hydro and Community
Facilities Division, Environmental Water Projects Department, San
Francisco, California.
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CONTENTS
Section
Foreword
Abstract
I INTRODUCTION
Purpose 1-1
Definition 1-1
Application 1-2
Limitations 1-3
II UNIT WASTEWATER TREATMENT PROCESSES
Unit Processes II-l
Unit Process Flow Sheets II-2
III COSTS OF UNIT PROCESSES
Cost Determinations III-l
Costs Included III-2
Costs Not Included III-3
Cost Curves for Unit Processes III-3
Factors Other Than Cost Considered in Selecting III-4
Wastewater Treatment Unit Processes
Calculation of Capital, O&M Cost, and Total Costs III-5
IV COMBINING UNIT PROCESSES FOR VIABLE
WASTEWATER TREATMENT SYSTEMS
Definition IV-1
Combined Unit Process Diagrams IV-1
V DETERMINING COST EFFECTIVENESS OF
WASTEWATER TREATMENT SYSTEMS
Procedure for Use of Diagrams and V-l
Comparaing Alternative Systems Costs
Examples of Comparing Cost-Effectiveness of V-4
Complete Wastewater Treatment Systems
APPENDIX A Unit Process Descriptions
APPENDIX B Cost Formulae
APPENDIX C Cost-Effectiveness Analysis Guidelines
ABBREVIATIONS AND BIBLIOGRAPHY
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TABLES, FLOW SHEETS, DIAGRAMS
Section
II
III
IV
V
Alternative Methods and Equipment for Various
Processes
Unit Process Flow Sheets
Properties and Cost of Common Waste Treatment
Chemicals and Costs of Energy
Factors Other than Cost Normally Considered in
Selection of Wastewater Treatment and Sludge
Handling Unit Processes
Unit Process Cost Curves
Combined Unit Processes for Wastewater
Treatment Systems
Combined Unit Processes for Sludge Handling
Systems
Example No. 1
Example No. 2
Example No. 3
No.
II-1
III-l
III-2
IV-1
IV-2
V-l
V-2
V-3
Page
II-5
II-6
III-5
III-7
III-6
IV-4
IV-5
V-7
V-ll
V-12
Appendix B Flow-Variable Cost Elements
B-l
B-5
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1. INTRODUCTION
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A GUIDE TO THE SELECTION OF COST-EFFECTIVE
WASTEWATER TREATMENT SYSTEMS
Section I - Introduction
1. 1 Purpose
The application of cost-effective methodologies is needed for the
development of sound waste treatment management systems responsive to
the Federal Water Pollution Control Act Amendments of 1972 (the Act).
This technical report represents an initial effort to aid in the identification
of most of the wastewater treatment process sequences (other than land
treatment and pond systems) currently available to meet point source discharge
standards. In addition to identifying a wide range of treatment alternatives
available to meet the standards, this technical report is intended to aid
in the further screening of alternatives as to their cost-effective potential.
1. 2 Definition
For waste treatment management systems, a cost-effective solution is
one which will minimize total resources costs to the nation over time to
meet the Federal and State water quality standards and treatment require-
ments. Resources costs include capital (construction and lands); operation,
maintenance and replacements; and social and environmental costs.
In comparing joint municipal-industrial waste treatment management
systems to separate systems, a cost-effective system is one in
1-1
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which the total resources cost over time are less than the total resources
costs of other alternative systems.
A cost-effective waste treatment management system may provide for
wastewater reuse when the sale or net value from wastewater reuse will,
at a minimum, offset any additional resources cost to the system which is
required to meet Federal and State water quality standards and treatment
requirements.
1. 3 Application
This publication is intended to aid water quality management planners,
decision makers at all levels of government, and design engineers in evalua-
ting cost-effective potential of alternative wastewater treatment systems.
This publication is not intended as a design manual but as an effective means
for making preliminary cost comparisons based upon the assumptions set
forth in this report. The cost-effectiveness data presented should be of parti-
cular value throughout the planning, project formulation, and preliminary
engineering process.
It is expected that the cost effectiveness data presented in the report will be
revised and updated periodically. This is a necessity since waste treatment
costs are continually changing, and new and improved waste treatment tech-
niques and methodologies are rapidly appearing. As more experience is
1-2
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gained in practice with the newer advanced wastewater treatment and
sludge handling processes, more cost data will become available for
analysis. Also, improvements in processes already in current use
will most likely result in significant cost changes.
1.4 Limitations
Although the information presented should be of particular value throughout
the planning, project formulation, and preliminary engineering process,
the reader should be aware of the limitations of this publication. He should
realize that the circumstances of a particular situation may alter the cost-
effectiveness data presented. For example, the influence of very cold
weather would likely eliminate from consideration a highly temperature
dependent process such as ammonia stripping and could change costs for
other systems such as activated sludge and trickling filters. Similarly,
if the percentage of industrial wastewater or inflow and infiltration is high
or if the composition of the waste stream differs markedly from the "typical1
influent wastewater quality assumed herein, modifications must be made in
choosing cost-effective systems. Similar adjustments would have to be
made if any of the design criteria as shown on the process flow sheets were
to be changed.
Additionally, the reader should be aware that not every wastewater treat-
ment method and piece of equipment is presented. Alternatives to the pro-
cesses considered are presented in Table II-l.
1-3
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2. UNIT WASTEWATER TREATMENT PROCESSES
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Section II - Unit Wastewater Treatment Processes
2. 1 Unit Processes
There are two basic areas of concern in wastewater treatment. One is the
removal of deleterious matter from wastewater: suspended solids, BOD, bacteria,
phosphorous and nitrogen. The Qjbher is handling a variety of sludges generated
within the wastewater treatment systems. Unit processes presently available
for wastewater treatment and sludge handling are presented at the end of this
chapter in the form of flow sheets.
Before developing costs associated with each unit process or making cost-
effective analyses, it was first necessary to evaluate relative treatment
efficiencies of the various unit processes and all combinations thereof. The
first step required in this evaluation was the selection of representative influent
wastewater characteristics. Based upon these characteristics and estimated
treatment efficiencies, effluent characteristics for each unit process were
determined. Nominal design criteria, equipment sizing and quantities and
characteristics of sludges generated from the various processes were then
established.
To determine effluent quality expected from each unit process, a "typical"
raw influent wastewater quality was chosen, as described below:
Biochemical Oxygen Demand, 5 days @ 20 ° C 210 mg/1
Total Suspended Solids 230 mg/1
Total Phosphorus (total as P) 11 mg/1
TKN (as N) 30 mg/1
Total - N (as N) 30 mg/1
PH 7.3
Alkalinity (as CaCO ) 300 mg/1
II-1
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The raw influent wastewater quality listed above is intended to represent
a rough average of a wide variety of wastewater qualities found in the United
States. The raw influent quality and process efficiencies chosen were deter-
mined from available literature listed in the bibliography. Design parameters
for equipment associated with each unit process were determined also from
available literature, including guidelines listed in the "Ten States Stanards"
and from recent engineering experience. They represent commonly accepted
values. From the selected design parameters and loadings on the processes,
the units were sized based on influent wastewater flow. The quantities of
sludges generated by the unit processes were calculated and sludge handling
units' sizes were based upon the sludge quantities, characteristics, and se-
lected design parameters.
2. 2 Unit Process Flow Sheets
All major equipment associated with each unit process are depicted on the
unit process flow sheets. Other equipment and appurtenances generally asso-
ciated with each unit process are included in the cost equations described in
the addendum even though not shown on the flow sheets.
Influent quality, effluent quality, design larameters, unit sizing and, where
appropriate, sludge quantities produced by the unit process are depicted on
the flow sheets. Also shown on the flow sheets, where applicable, are che-
mical quantities used, air requirements and waste gases produced. Other
quality parameters are presented where necessary for specific unit process
characterization.
II-2
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Table II-1 lists the process methods and basic equipment upon which cost
data are based. The Table also lists alternative methods and/or equipment
that could be used in place of those selected.
Certain unit processes are designed to remove specific pollutants: suspended
solids, BOD, phosphorus, or nitrogen compounds. In the course of removing
the primary pollutants for which the unit process is intended, other deleter-
ious materials are partially removed as well. For example, unit processes
comprising chemical treatment are designed primarily to remove phosphorus,
but these steps are also effective in removing suspended solids and a relatively
high percentage of BOD. A system comprising addition of chemicals (lime,
alum or ferric chloride) in the primary sedimentation process to effect phos-
phorus removal would produce an effluent of lower BOD content than would con-
ventional primary sedimentation. Because of the differences in BOD content
of the effluent from primary treatment in the two systems, design parameters
of secondary treatment would change accordingly, even if the same secondary
treatment process was used in both cases.
Therefore, design parameters and all characteristics of a given unit operation
will vary depending upon the primary purpose of a unit process in the system,
the unit processes preceding in the system and, in a few cases, following in
the system. For this reason, in most cases there are a number of flow sheets
for a given unit process. For example, there are five flow sheets for the pri-
mary sedimentation process and eight flow sheets for the activated sludge
II - 3
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process. In the sludge handling unit processes, there are nine flow sheets
for the sludge dewatering process and seven flow sheets for sludge incinera-
tion. Each flow sheet is specific to a given condition and may be identified
by the following:
• The title of each flow sheet identifies the unit process and the function
of the process in the system.
• For liquid treatment unit processes, the sources of influents that can be
treated in the particular flow sheet are listed.
• For sludge handling unit processes, the sources of sludges that can be
handled in the particular flow sheet are listed.
By these means, compatible unit processes can be selected and used as build-
ing blocks to form complete systems.
11-4
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TABLE II-l
ALTERNATIVE METHODS AND EQUIPMENT
FOR VARIOUS PROCESSES
Process
Sedimentation
Thickening
Secondary Treatment
Aeration
Filtration
Carbon Adsorption
Digestion
Sludge Stabilization
Dewatering
Incineration
Recalcination
Disinfection
Chemical Treatment
(Primary & Tertiary)
Biological Nitrification
Biological
Denitrifi cation
Ion Exchange and
regeneration
Methods and Equipment
Selected
Circular Units
Gravity
Trickling Filters
Activated Sludge
Air (Media)
Diffusers (Method)
Dual-Media
Granular
Anaerobic
Digestion
Heat Treatment
Air Drying
Vacuum Filters
Multiple-Hearth
Multiple-Hearth
Chlorination
Flocculation-
Clarifiers
Separate suspended
growth Aeration Basin
Separate basin with
suspended growth
Ammonia Stripping
Tower, to remove
NH3-N from
regenerant
Preliminary Treatment
Grit Removal Gravity Grit Chamber
Screening
Flow Measurement
Bar Racks
Par shall Flume
Alternative
Methods & Equipment
Rectangular Units
Flotation
Rotary Biological Filters
Oxygen
Mechanical
Brushes
Microscreens
Multi-media
Single-media
Powdered
Aerobic
Chemical-Chlorine; Lime
Sludge Lagoons
Centrifuges
Pressure Filters
Fluid-Bed
Rotary Kiln
Fluid-Bed
Rotary Kiln
Ozonation
Separate Flocculation
& Clarification Units
Combined with Activated
Sludge Basin or separate
basin with fixed growth
Separate basin with
Fixed growth or com-
bined with nitrification
Electrolysis with Break
Point Chlorination to
remove NH3-N from
regenerant
Aerated Grit Chamber
Cyclone Separation
Comminutors
Palme r-Bowlus Flume
II-5
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WASTEWATER TREATMENT PROCESSES
FLOW SHEETS
Preliminary Treatment
Pump ing
Primary Sedimentation
Trickling Filter
Activated Sludge
Filtration
Activated Carbon
Two Stage Tertiary Lime
Biological Nitrification
Biological Denitrification
Ion Exchange
Breakpoint Chlorination
Ammonia Stripping
Disinfection
AA
AB
A-l thru A-5
B-l thru B-3
C-l thru C-8
D
E
F-l thru F-2
G-l thru G-4
H
I
J
K
R
II-7
II-8
II- 9 thru II- 13
11-14 thru 11-16
II- 17 thru II- 24
11-25
11-26
11-27 thru 11-28
11-29 thru 11-32
11-33
II-34
11-35-
11-36
11-37
SLUDGE HANDLING PROCESSES
FLOW SHEETS
Anaerobic Digestion
Heat Treatment
Air Drying
De watering
Incineration
Re calcination
L-l & L-2
M-l &c M-2
N-l fe N-2
O-l thru O-9
P-l thru P-7
Q-l thru Q-3
11-38 thru II-39
11-40 thru 11-41
11-42 thru 11-43
11-44 thru 11-52
11-53 thru II- 59
11-60 thru 11-62
II-6
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AA. PRELIMINARY TREATMENT
Influent: Raw Waste water
GRINDING —I
SCREENINGS
1-3 ft
3
RAW W.W.-
BAR RACK
TO DISPOSAL
BOD = 210mg/l
SS = 230mg/l
P =11 mg/l
GRIT
2-5 ft3
Design criteria in bold type arc per
mgd influent wastewater flow.
II-7
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AB. RAW WASTEWATER PUMPING
Influent: Effluent from Preliminary Treatment AA
Q*
TDH = 30ft
BOD = 210mg/l
SS = 230mg/l
P =11 mg/l
*Peak Capacity (with largest unit out of service) = 2 x Q
Design criteria in bold type are per
mgd influent wastewater flow.
II-8
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A-1. PRIMARY SEDIMENTATION - CONVENTIONAL
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
1250 ft2
BOD = 210mg/l
SS = 230mg/l
P =11 mg/l
PRIMARY
SEDIMENTATION
2
4% Solids
1000 Ib
2 gpm
BOD = 140 mg/l
-*• SS = 110 mg/l
P = 10 mg/l
8% Solids
1000 Ib
1 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II-9
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A-2. PRIMARY SEDIMENTATION - TWO-STAGE LIME ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
BOD =210 mg/l
SS = 230 mg/l
P =11 mg/l
BOD= 40 mg/l
SS = 30 mg/l
P =1.0 mg/l
1000gpd/ft2
1000 ft2
FLOCCULATOR
CLARIFIER
FLOCCULATOR
CLARIFIER
5% Solids
7500 Ib
13 gpm
THICKENER
25 Ib/ft2/day
300ft2
10% Sol ids
7500 Ib
6.5 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-10
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A-3. PRIMARY SEDIMENTATION - SINGLE-STAGE LIME ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
BOD =210mg/l
SS = 230 mg/l
P =11 mg/l
1000 gpd/ft
1000 ft2
Dosage = 200 mg/l
1670 Ib
FLOCCULATOR
CLARIFIER
pH > 9.5
BOD = 100 mg/l
SS = 65 mg/l
P = 2.7 mg/l
5% Sol ids
4200 Ib
7 gpm
THICKENER
25 Ib/ft2/day
170ft2
10% Sol ids
4200 Ib
3.5 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II- 1 1
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A-4. PRIMARY SEDIMENTATION -ALUM ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
BOD = 210mg/l
SS = 230mg/l
P =11 mg/l
600 gpd/ff*
1670 ft2
Dosage = 170 mg/l
1420 Ib
FLOCCULATOR
CLARIFIER
2% Solids
1900 Ib
8 gpm
BOD = 100 mg/l
SS = 65 mg/l
P = 2.2 mg/l
THICKENER
8 Ib/ft2/day
240ft2
4% Solids
1900 Ib
4 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-12
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A-5. PRIMARY SEDIMENTATION - FeCI3 ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
BOD =210 mg/l
SS = 230 mg/l
P =11 mg/l
600 gpd/fV
1670ft2
Dosage = 80 mg/l as FeClg
670 Ib
CaO = 35 mg/l
290 Ib
FLOCCULATOR
CLARIFIER
BOD = 100 mg/l
SS = 65 mg/l
P = 2.2 mg/l
2% Solids
2000 Ib
9 gpm
THICKENER
8 Ib/ft2/day
250 ft2
4% Solids
2000 Ib
4.5 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II- 1
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B-1. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation — Conventional
A-1
Reci rculation = I :
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l ,
30 Ib influent BOD/1000 ft3/day
39,000 cu ft
700 gpd/h"
1430 ft2
FINAL
SEDIMENTATION
3% Solids
275 Ibs
0.8 gpm
BOD =30 mg/l
SS =35 mg/l
P = 9 mg/l
lOlb/ftVday
28ft2
6% Solids
275 Ibs
0.4 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-14
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B-2. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation — Single-Stage Lime Addition A-3
Reci rculation =1:1
BOD = 100mg/l
SS = 65mg/l
P = 2.7 mg/l,
30 Ib influent BOD/1000 ft3/day
27,800 ft3
700 gpd/ft2
1430 ft2
FINAL
SEDIMENTATION
BOD = 20 mg/l
SS = 15 mg/l
P = 2.2 mg/l
3% Sol ids
200 Ibs
0.6 gpm
10lb/fr/day
20ft2
6% Solids
200 Ibs
0.3 gpm
Design criteria in bold type are per
mgd" influent wastewater flow.
11-15
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B-3. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation — Alum or FeClg Addition A-4 or A-5
Reci rcula tion = 1:
BOD = 100 mg/l
SS = 65 mg/l
P = 2.2 mg/l
30 Ib influent BOD/1000 ft3/day
27,800 ft3
700 gpd/f H
1430 ft2
FINAL
SEDIMENTATION
BOD= 20 mg/l
SS = 15 mg/l
P =1.8 mg/l
3% Solids
200 Ibs
0.6 gpm
6% Solids
200 Ibs
0.3 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II-16
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C-1. ACTIVATED SLUDGE - CONVENTIONAL
Influent: Effluent from Primary Sedimentation —
Conventional A-1
1000cf/lbBOD
810cfm
AIR
700 gpd/ft'
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
i
f 1430ft2 BOD = 20 mg/l
AERATION
35 Ib BOD/1 000 ft3/day
33,300 ft3
SS = 25 mg/l
QnniMPMTA-r,™ P = 8m9/'
\Tx
DT 6hr 0.8% Sol ids
^^ 500 Ibs
RAS viy " ai""
THICKENER
5 Ib/ft2/day
3% Solids
500 Ibs
1.2 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II- I 7
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C -2. ACTIVATED SLUDGE
Influent: Effluent from Primary Sedimentation — Single-Stage Lime Addition A-3
1000cf/lbBOD
580 cf m
AIR
700 gpd/ft'
BOD = 100 mg/l
SS = 65 mg/l
P = 2.7 mg/l
i j
T 1430ft2 BOD = 15 mg/l
AERATION
loading - 35 Ib BOD/1000 ft3
22,300 ft3
DT = 4 hr
/C\
SS = 15 mg/l
«n,McNMTATiniu P = 2'1 mg/'
/day ^s f
0.8% Solids
RAS W JbU lbs
A 3.5 gpm
3% Solids
350 lbs
1.0 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
I- 18
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C-3. ACTIVATED SLUDGE
Influent: Effluent from Primary Sedimentation - Alum or FeClg Addition A-4 or A-5
1000cf/lbBOD
580 cfm
AIR
BOD = 100mg/l
SS = 65 mg/l
P = 2.2 mg/l
AERATION
700 gpd/ft'
1430 ft2
FINAL
SEDIMENTATION
loading = 35 Ib BOD/1000ft3/day
22,300 ft3
DT = 4 hr
BOD = 15 mg/l
SS = 15 mg/l
P = 1.8 mg/l
RAS
0.8% Solids
350 Ibs
3.5 gpm
THICKENER
5 Ib/ft2/day
70ft2
3% Solids
350 Ibs
1.0 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II- 19
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C-4. ACTIVATED SLUDGE + ALUM ADDITION
Influent: Effluent From Primary Sedimentation — Conventional A-1
1000cf/lb BOD
810 cfm
AIR
BLOWER
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
700 gpd/ft2
1430 ft2
AERATION
RAS
FINAL
SEDIMENTATION
BOD = 20 mg/l
SS = 20 mg/l
P = 2 mg/l
35lb/1000ftJ/day
33,300 ft3
D.T. = 6 hr
0
1% Solids
900 Ibs
7.5 gpm
ALUM
160 mg/l
1330 Ib
3% Sol ids
900 Ibs
2.5 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-20
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C-5. ACTIVATED SLUDGE - FeCI3 ADDITION
Influent: Effluent from Primary Sedimentation — Conventional A-1
1000 cf/lb BOD
810 cfm
AIR
BLOWER
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
700 gpd/ft'
1430 ft2
AERATION
RAS
FINAL
SEDIMENTATION
35 Ib BOD/1000 ft°/day
33,300 ft3
DT = 6 hr
0
Fed,
70 mg/l FeCI3
580 Ibs
CaO = 30 mg/l
250 Ibs
BOD = 20 mg/l
SS = 20 mg/l
P = 2 mg/l
1% Sol ids
1000 Ibs
8.5 gpm
THICKENER
5 Ib/ft2/day
200 ft2
3% Solids
1000 Ibs
2.9 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
II- ?. 1
-------
C-6. ACTIVATED SLUDGE - HIGH RATE
Influent: Effluent from Primary Sedimentation — Conventional
A-1
600 cf air/lb BOD
490 cf m
AIR
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
700 gpd/ft2
1430ft2
AERATION
FINAL
SEDIMENTATION
11,100ft3
DT = 2 hr
BOD = 40 mg/l
SS = 35 mg/l
P = 9 mg/l
RAS
1% Solids
425 Ibs
3.5 gpm
THICKENER
5 Ib/ft2/day
85ft2
3% Sol ids
425 Ibs
1.2 gpm
Design criteria in bold type are per
mgd influent wastewater flow
11-22
-------
C-7. ACTIVATED SLUDGE - HIGH RATE + ALUM ADDITION
Influent: Effluent from Primary Sedimentation — Conventional A-1
600 cf air/lb BOD
490 cfm
AIR
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
700 gpd/f2
1430 ft2
AERATION
11.100ft3
DT = 2hr
RAS
FINAL
SEDIMENTATION
BOD = 40 mg/l
SS = 35 mg/l
P =2 mg/l
1% Solids
1000 Ibs
8.5 gpm
THICKENER
5 Ib/ft2/day
200 ft2
ALUM
160 mg/l
1330 Ibs
3% Solids
1000 Ibs
3.0 gpm
Design criteria in bold type are per
mgd influent wastewater flow
11-23
-------
C-8. ACTIVATED SLUDGE - HIGH RATE + FeCI3 ADDITION
Influent: Effluent from Primary Sedimentation — Conventional A-1
600 cf air/lbBOD
490 cf m
AIR
BOD = 140 mg/l
SS = 110 mg/l
P = 10 mg/l
700 gpd/ft2
1430 ft 2
AERATION
11,100ft3
DT = 2hr
RAS
FINAL
SEDIMENTATION
BOD = 40 mg/l
SS = 35 mg/l
P = 2 mg/l
1% Solids
1000 Ibs
8.5 gpm
THICKENER
5 Ib/ft2/day
200 ft2
FeCU
70 mg/l FeCI3
580 Ibs
30 mg/l CaO
250 Ibs
3% Solids
1000 Ibs
3.0 gpm
Design criteria in bold type are per
mgd influent wastewater flow
11-24
-------
D. FILTRATION
Influent: Effluent from Primary Sedimentation - Two Stage Lime Addition
A-2
Activated Sludge - Alum or FeClg Addition
C-4 or C-5
Two Stage Tertiary Lime Treatment
F-1 or F-2
Trickling Filter B-2, B-3
Activated Sludge C-2, C-3
Biological Nitrification G-1, G-2, G-3, G-4
Biological Denitrification H
Breakpoint Chlorination J
Ammonia Stripping K
TO HEAD OF PLANT
STORAGE
FILTER BACKWASH
WASTE
40,000 gal
BOD =
SS =
P
20 mg/l *
18 mg/l *
2.0 mg/l *
•**."/ " ' " ' " ° ' ° ° •
' ' FILTER . ' ,
' ° 24 hour filter run , ,
9 ~ o * „ Oj-j°
4 gpm/ft2
180ft2
BOD =
SS =
P
10 mg/l
5 mg/l
1 .0 mg/l
0
BACKWASH
RESERVOIR
'Averaged values from above influent
Design criteria in bold type are per
mgd influent wastewater flow
11-25
-------
E. ACTIVATED CARBON
Influent: Effluent from Filtration D
TO HEAD OF PLANT
BOD = 10mg/l
SS = 5 mg/l
P = 1.0 mg/l
30 min contact time
300 Ibs Carbon
ADSORPTION
TOWER .
SPENT
CARBON
BOD = 4 mg/l
SS = 2 mg/l
P = 0.8 mg/l
BACKWASH*
©
DEWATER
SPENT
CARBON
STORAGE OF
SPENT
CARBON
80 Ibs/ffVday
1700°F
1 Ib steam/ 1 Ib carbon
4500 Btu/ 1 Ib carbon
AFTERBURNER
AIR SCRUBBER
REGENERATION
FURNACE
CARBON
SLURRY
TANK
SLURRY WATER
MAKE-UP
CARBON
Design criteria in bold type are per
mgd influent waste water flow
11-26
Backwash frequency
varies from once every
2 days to once every
2 weeks.
-------
F-1. TWO-STAGE TERTIARY LIME TREATMENT
Influent: Effluent from Trickling Filter System B-1
Dosage = 400 mg/l
3340 Ib
BOD =
SS =
P
30 mg/l
35 mg/l
9 mg/l
100Qgpd/ft<
1000 ft2
FLOCCULATOR
CLARIFIER
1000 gpd/ft2
1000ft2
FLOCCULATOR
CLARIFIER
BOD
SS
P
10 mg/l
10 mg/l
0.5 mg/l
5% Solids
6300 Ib
10gpm
THICKENER
40 Ib/ft2/day
160ft2
10% Solids
6300 Ib
5gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-27
-------
F-2. TWO-STAGE TERTIARY LIME TREATMENT
Influent: Effluent from Conventional Activated Sludge C-1
Dosage = 400 mg/l
3340 Ib
BOD = 20 mg/l
ec - oc mn/l
P = 8 mg/l
LIME
\
i
RAPID
MIX
j
co2 co2
1000gpd/ft2 1000gpd/ft2
1000ft2 1000ft2 800= 8 mg/l
CC - Q mn/1
|^ , , , P = 0.5 mg/l
' FLOCCULATOR FLOCCULATOR
M CLARIFIER ^ I M CLARIFIER \
(SP) (SP)
5% Sol ids
6300 Ib
i • 10 gpm
THICKENER
40 Ib/ft/day
160ft2
10% Sol ids
6300 Ib
5 gpm
Design criteria in bold type are per
mgd influent wastewater flow.
11-28
-------
G-1. BIOLOGICAL NITRIFICATION
Influent: Effluent from High Rate Activated Sludge C-6
600 Ib O2/hr
575 cfm of Air @ 10% oxygen transfer efficiency
AIR
I BLOWER
BOD = 40 mg/l
SS = 35 mg/l
TKN = 29 mg/l
Total - N = 30 mg/l
700 gpd/ftx
1430ft2
AERATION
CLARIFIER
BOD = 12 mg/l
SS = 15 mg/l
TKN = 1 mg/l
Total-N =30 mg/l
DT = 4 hr
22,300ft3
RAS
Design criteria in bold type are per
mgd influent wastewater flow
11-29
-------
G-2. BIOLOGICAL NITRIFICATION
Influent: Effluent from Trickling Filter System B-1
460 Ibs O2/hr
440 cfm Air at 10% Oxygen transfer efficiency
AIR
BLOWER
BOD = 30 mg/l
SS = 35 mg/l
TKN = 29 mg/l
Total-N = 30 mg/l
700 gpd/ft''
1430ft2
AERATION
BOD = 10 mg/l
SS = 15 mg/l
TKN = 1 mg/l
Total - N = 30 mg/l
CLARIFIER
DT =4hr
22,300ft3
RAS
Design criteria in bold type are per
mgd influent wastewater flow
11-30
-------
G-3. BIOLOGICAL NITRIFICATION
Influent: Effluent from Primary Sedimentation-Single Stage Lime Addition
A-3
Primary Sedimentation — Alum or FeCI3 Addition
A-4 or A-5
910 Ibs O2/hr
871 cfm Air @ at 10% oxygen transfer efficiency
AIR
BLOWER
BOD = 100 mg/l
SS = 65 mg/l
TKN = 29 mg/l
Total - N = 30 mg/l
700 gpd/ft^
1430ft2
AERATION
DT = 4 hr
22,300 ft3
BOD = 25 mg/l
SS = 20 mg/l
TKN = 1 mg/l
Total-N = 30 mg/l
RAS
Design criteria in bold type are per
mgd influent wastewater flow
11-31
-------
G-4. BIOLOGICAL NITRIFICATION
Influent: Effluent from Primary Sedimentation — 2 Stage Lime Addition A-2.
or High rate Activated Sludge + Alum or FeClg Addition C-7 or C-8
600 Ibs O2/hr
530 cfm Air @ 10% oxygen transfer efficiency
AIR
BOD = 40 mg/l
SS = 30 mg/l
TKN = 29 mg/l
Total - N = 30 mg/l
BLOWER
1430ft2
700 gpd
AERATION
CLARIFIER
D.T. = 4 hr
22,300 ft3
BOD = 12 mg/l
SS = 15 mg/l
TKN = 1 mg/l
Total - N = 30 mg/l
RAS
Design criteria in bold type are per
mgd influent wastewater flow
11-32
-------
H. BIOLOGICAL DENITRIFICATION
Influent: Nitrification Process Effluents
G-1
G-2
G-3
G-4
4.5 Ibs/lb NO3-N
1090 Ibs
METHANOL
150 Ib air/hr
30 Ib O2/hr
AIR OR OXYGEN
BOD =
SS =
1 KIM -
Total -N =
I
15 mg/l*
16mg/l*
1 mg/l
30 mq/l
i
j f \ BLOWE
ANAEROBIC
REACTOR
AERATION
DT = 2hrs DT = 15min
11,100ft3 1400ft3
R
700 gpd/ft2
1430 ft2
CLARIFIER
^^
BOD =
SS =
TKN =
Total N =
15 mg/l
16 mg/l
1 mg/l
3 mg/l
RS
'Averaged from G-1 through G-4; the design parameters
for H are independent of these values.
Design criteria in bold type are per
mgd influent wastewater flow.
11-33
-------
I. ION-EXCHANGE
Influent: Filtration - Effluent
D
Activated Carbon Treatment Effluent
E
AMMONIA
ABSORBER
TKN = 29mg/l
Total-N =30mg/l
1.5 gpm/ft3
450ft3
INFLUENT-
NH,
AMMONIA REMOVAL
FROM REGENERANT
SPENT
REGENERANT
ION EXCHANGE
BEDS
MAKE-UP
CLINOPTILOLITE
TKN = < 1 mg/l
Total - N = 1 mg/l
EFFLUENT
NaCI SOLUTION
CaCU
REGENERANT
STORAGE
RECYCLED
REGENERANT
MAKE-UP
REGENERANT
Length of service cycle approx. 175 bed
volumes or every 15 hrs.
In service 95% of time, regenerating 5% of time.
Design criteria in bold type are per
mgd influent wastewater flow
11-34
-------
J. BREAK POINT CHLORINATION
Influent: Effluent from A-2, B-1, B-2, B-3, C-1, C-2,
C-3, C-4, C-5. F-1, F-2
10lbCI2/lbNH3-N
2300 Ibs CI2
CHLORINE
ADDITION
TKN = 29mg/l
Total - N = 30 mg/l
r~
DT = 30 min
2800ft3
BREAK POINT CHLORINATION
TKN = 1 mg/l
Total - N = 3 mg/l
CaO
2100 Ibs
0.9 Ib CaO/lb CI2
L
Assumed alkalinity of 200 ppm
Design criteria in bold type are per
mgd influent wastewater flow.
11-35
-------
K. AMMONIA STRIPPING
Influent: Effluent from First Stage of Two Stage Tertiary Lime Treatment F-1 or F-2
Ca(OH)2
pH ^ 11
CHEMICALS
FOR pH CONTROL
NH3. AIR
TKN ~ 29 mg/l
Total - N ~ «*U mg/l ,
i
2 gpm/ft2
350 ft2
AMMONIA
STRIPPING
TKN - 2 mg/l
Total - N ~ 3 mg/l
' 400 cfm/gpm
280,000 cf m
AIR
*90% removal efficiency at 80°F ambient air temperature
Design criteria in bold type are per
mgd influent wastewater flow.
11-36
-------
R. DISINFECTION
Influent: Any Process Effluent
CI2
STORAGE
ONE TON
CYLINDERS
FEEDER
HOUSE
ANY
PROCESS -
INFLUENT
2780 ft3
Dosage = 10mg/l
83lbs
CONTACT
BASIN
-•»• < 200 Fecal
Coliform Bacteria
per 100ml.
D.T.>15min.
'Peak Flow = 2Q
Design criteria in bold type are per
mgd influent wastewater flow.
11-37
-------
L-1. ANAEROBIC DIGESTION
Sludge Influent: Primary Sedimentation — Conventional plus Trickling Filter
A-1 + B-1
Primary Sedimentation — Conventional plus Activated
Sludge — Conventional
A-1 + C-1
Primary Sedimentation — Conventional plus Activated
Sludge — High rate
A-1 + C-6
SUPERNATANT TO HEAD OF PLANT
70% Volatile Solids
5% Solids
1400 Ibs
2.3 gpm
AVERAGE THICKENED
SLUDGE
10ft3/lb
Volatile Solids
9800 ft3 GAS
600 BTU/cu ft
5.9 x 106 BTU
MIXING
4% Solids
54% Volatile Solids
910 Ibs
1.9 gpm
*- SURPLUS GAS
Digestor capacity calculation based on Volatile
Solids loading factor of 0.16 Ib/day/cuft
Design criteria in bold type are per
mgd influent wastewater flow.
11-38
-------
L-2. ANAEROBIC DIGESTION
Sludge Influent: Primary Sedimentation — Conventional and Activated Sludge
or High Rate Activated Sludge — Alum or Fed-? Addition
A-1 + C-4 or C-5
A-1 + C-7 or C-8
Primary Sedimentation — Alum or FeCl3 Addition + Activated
Sludge or-Trickling Filter
A-4 + B-3 or C-3
A-5 + B-3 or C-3
SUPERNATANT TO PRIMARY
50% Volatile Solids
4% Solids
2100 Ibs-Ave.
4.4 gpm
AVERAGE THICKENED
SLUDGE
10cuft/lb
Volatile Solids
10,500 ft2 Gas
600 BTU/ft3
6.3 x 106 BTU
MIXING
25% T. Sol. Reduction
33% Volatile Solids
3% Solids
1600 Ibs-Ave.
4.2 gpm
SURPLUS GAS
Digestor capacity based on Volatile Solids
loading factor of 0.129 Ib/day/cu ft
Design criteria in bold type are per
mgd influent wastewater flow.
11-39
-------
M-1. HEAT TREATMENT
Sludge Influent: Biological Primary + Secondary - Conventional or High rate
A-1 + B-1
A-1 + C-1
A-1 + C-6
168hr/wk Operation
HEAT EXCHANGER
5% Solids
1400 Ibs
2.3 gpm
AVERAGE
THICKENED
SLUDGE
HEAT REACTOR
DT = 30 min
135 gal/hr
390° F
HEAT
TO HEAD
OF PLANT *
AERATION
BOD = 5000 mg/l
10% Solids
1400 Ibs
1.2 gpm
TO
DEWATER
20 Ib/ft2/day
70ft2
SUPERNATANT
1.1 gpm
35 Ib BOD/1000 ft3/day
1900 ft3
AIR
1000cf/lbBOD
50cfm
Design criteria in bold type are per
mgd influent wastewater flow
11-40
-------
M-2. HEAT TREATMENT
Sludge Influent: Primary Sedimentation + Activated Sludge or high rate activated sludge
A-1 + C-4 or C-5 _ Alum or FeCI3 Addition
A-1 + C-7 or C-8
Primary Sedimentation — Alum or FeCl3 Addition + Activated Sludge
or Trickling Filter
A-4 + B-3 or C-3
A-5 + B-3 or C-3
168 hr/wk operation
HEAT EXCHANGER
4% Solids
2100 Ibs
4.4 gpm
AVERAGE
THICKENED
SLUDGE
8% Sol ids
2100 Ibs
2.2 gpm
TO
DE WATER
HEAT REACTOR
DT = 30 min
265 gal/hr
390°F
HEAT
TO HEAD
OF PLANT
AERATION
BOD = 5000 mg/l
10 Ib/ft2/day
210ft2
SUPERNATANT
2.2 gpm
;35lb BOD/1000 ft3/day
3780 ft3
(CJ
AIR
1000cf/lbBOD
100 cfm
Design criteria in bold type are per
mgd influent wastewater flow.
11-41
-------
O-1. DE WATER ING
Sludge Influent: Primary + Secondary — Conventional or High rate
A-1 + B-1
A-1 + C-1
A-1 + C-6
5% Solids
1400 Ibs
260 ton/yr
3200 gal
5 Ib/ft2/hr
23ft2
12 hr/day operation
CHEMICALS
STORAGE AND
FEEDING EQUIPMENT
Ferric Chloride 35 Ibs
CaO 105 Ibs
*- DEWATERED SLUDGE
FILTRATE
RECEIVER
20% Solids
1330 Ibs
245 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
II- 44
-------
0-2. DEWATERING
Sludge Influent: Primary-Conventional + Secondary-Alum or FeCI3 Addition
A-1 + C-4 or C-5
A-1 + C-7 or C-8
Primary-Alum or FeCl3 Addition + Secondary
A-4 + B-3
A-4 + C-3
A-5 + B-3
A-5 + C-3
4% Solids
2100 Ibs
380 ton/yr
6350 gal
4 Ib/ft2/hr
44ft2
12 hr/day operation
CHEMICALS
STORAGE AND
FEEDING EQUIPMENT
Ferric Chloride 50 Ibs
CaO 190 Ibs
DEWATERED SLUDGE
FILTRATE
RECEIVER
20% Solids
1900 Ibs
345 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-45
-------
O-3. DEWATERING
Sludge Influent: Primary Sedimentation - Two Stage Lime Addition A-2
10% Solids
7500 Ib
1370 ton/yr
9000 gal
7 Ib/ft2/hr
90ft2
12hr/day operation
*- DEWATERED SLUDGE
30% Solids
7100 Ib
1300 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-46
-------
O-4. DEW ATE RING
Sludge Influent: Primary Sedimentation — Single Stage Lime Addition
+ Trickling Filter or Activated Sludge
A-3 + B-2
A-3 + C-2
8% Solids
4500 Ibs
825 ton/yr
6500 gal
6 Ib/ft2/hr
63ft2
12 hr/day operation
*»• DEWATERED SLUDGE
FILTRATE
RECEIVER
25% Solids
4250 Ibs
775 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-47
-------
O-5. DEW ATE RING
Sludge Influent: Digested Primary + Secondary - Conventional (L-1)
4% Solids
910 Ibs
170ton/yr
2700 gal
5 Ib/ft2/hr
15ft2
12 hr/day operation
CHEMICALS
STORAGE AND
FEEDING EQUIPMENT
Ferric Chloride
CaO
DEWATERED SLUDGE
FILTRATE
RECEIVER
35 Ibs
65 Ibs
20% Solids
865 Ibs
158 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-48
-------
O-6. DEWATERING
Sludge Influent: Digested Primary + Secondary (Alum or FeCI-j Addition) (L-2)
3% Solids
1600 Ibs
290 ton/yr
6100 gal
5 Ib/ft2/hr
2g ff2 12 hr/day operation
CHEMICALS
STORAGE AND
FEEDING EQUIPMENT
Ferric Chloride 60 Ibs
Lime 135 Ibs
DEWATERED SLUDGE
FILTRATE
RECEIVER
20% Solids
1500 Ibs
275 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-49
-------
O-7. DEWATERING
Sludge Influent: Two-Stage Tertiary Lime Treatment F-1 or F-2
10% Sol ids
6300 Ibs
1150ton/yr
7200 gal
8 Ib/ft2/hr
-R 2 12 hr/day operation
*- DEWATERED SLUDGE
FILTRATE
RECEIVER
30% Solids
6000 Ib
llOOton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-50
-------
O-8. DEWATERING
Sludge Influent: Heat-Treated Primary + Secondary - Conventional
M-1
10% Solids
1400 Ibs
255 ton/yr
1700 gal
10 Ib/ft2/hr
12ft2
12 hr/day operation
•» DEWATERED SLUDGE
FILTRATE
RECEIVER
35% Solids
1330 Ibs
245 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-51
-------
O-9. DEWATERING
Sludge Influent: Heat Treated Primary + Secondary (Alum or FeCI3 Addition) M-2
8% Sol ids
2100 Ibs
385 ton/yr
3200 gal
8 Ib/ft2/hr
on f*2 12 hr/day operation
*- DEWATERED SLUDGE
FILTRATE
RECEIVER
35% Solids
1900 Ibs
345 ton/yr
ATMOSPHERE
TO HEAD
OF PLANT
Design criteria in bold type are per
mgd influent wastewater flow.
11-52
-------
P-1. INCINERATION
Sludge Influent: Dewatered Primary + Secondary — Conventional O-1
12hr/day operation
115lbs/hr
70% Volatile Organic Solids
20% Solids
1330 Ibs
245 ton/yr
AFTERBURNER
AIR SCRUBBERS
ASH TO DISPOSAL
35 Ibs/hr
AUXILIARY
FUEL
Design criteria in bold type are per
mgd influent wastewater flow.
11-53
-------
P-2. INCINERATION
Sludge Influent: Dewatered Primary + Secondary
(Alum or FeCI3 Addition) O-2
12 hr/day operation
160 Ibs/hr
40% Volatile Organic Solids
20% Solids
1900 Ibs
345 ton/yr
AFTERBURNER
AIR SCRUBBERS
ASH TO DISPOSAL
95 Ibs/hr
AUXILIARY
FUEL
Design criteria in bold type are per
mgd influent wastewater flow.
11-54
-------
P-3. INCINERATION
Sludge Influent: Primary Sedimentation - Two-Stage Lime Addition O-3
12 hr/day operation
330 Ib/hr
12% Volatile Organic Solids
30% Sol ids
4000 Ib
730 ton/yr
AFTERBURNER
AIR SCRUBBERS
ASH TO DISPOSAL
290 Ib/hr
AUXILIARY
FUEL
Design criteria in bold type are per
mgd influent waste water flow.
11-55
-------
P-4. INCINERATION
Sludge Influent: Dewatered Primary Sedimentation — Single Stage Lime Addition O-4
12 hr/day operation
200 Ibs/hr
35% Volatile Organic Solids
25% Solids
2450 Ibs
450 ton/yr
AFTERBURNER
AIR SCRUBBERS
-*• ASH TO DISPOSAL
135 Ibs/hr
AUXILIARY
FUEL
Design criteria in bold type are per
mgd influent wastewater flow.
11-56
-------
P-5. INCINERATION
Sludge Influent: Dewatered Tertiary Two-Stage Lime Treated + Dewatered Primary and
Secondary - Conventional
O-7 + O-1
12 hr/day operation
230 Ibs/hr
40% Volatile Organic Solids
30% Solids
2800 Ibs
510ton/yr
TO AFTERBURNER
AIR SCRUBBER
1500 Ibs LIME SLUDGE
1300 Ibs PRIM SEC SLUDGE
ASH TO DISPOSAL
140 Ibs/hr
AUXILIARY
FUEL
Design criteria in bold type are per
mgd invluent wastewater flow
11-57
-------
Q-1. RECALCINATION
Influent: Dewatered Sludge From Two-Stage Lime Addition in Primary
(0-3)
12% Volatile Organic Solids
30% Solids
3100 Ibs
570 ton/yr
4000 Ib
730 ton/yr
TO INCINERATION
12 hr/day operation
1200 Ib
100 Ib/hr
TO AFTERBURNER
AIR SCRUBBER
CO2 COMPRESSOR
90% CaO
3000 Ib
250 Ib/hr
LIME
35% CaO
1900lb
160 Ib hr
MAKEUP
LIME
STORAGE
LIME
REACTOR
Assumptions: 60% Solids recovery in furnace
Minimum of 75% purity by weight of Ca(OH>2
feed to lime rapid mix
Design criteria in bold type are per
mgd influent wastewater flow
11-60
-------
Q-2. RECALCINATION
Influent: Dewatered Sludge from Single Stage Lime Addition In Primary
Sedimentation + Sludge From Secondary Treatment
(0-4)
50% CaCO3
50% Other
20% Volatile Organic Solids
25% Solids
1800 Ibs
330 ton/yr
2450 Ibs
450 ton/yr
TO INCINERATION
12 hr/day operation
900 Ibs
75 Ibs/hr
TO AFTERBURNER
AIR SCRUBBER
90% CaO
1550lb
LIME
COMPRESSOR
MAKEUP
LIME
STORAGE
30% CaO
900 Ib
75 Ib/hr
LIME
RAPID MIX
Assumptions: 50% solids recovery in furnace
Minimum of 75% purity by weight of Ca(OH)2
feed to lime rapid mix
Only lime sludge is recalcined.
Design criteria in bold type are per
mgd influent wastewater flow
11-61
-------
Q-3. RECALCINATION
Influent: Dewatered Sludge From - Two-Stage Tertiary Lime Treatment
(0-7)
70% CaC03
30% Other Solids
4500 Ib
820 ton/yr
375 Ib/hr
i
— — \
1500 Ib
270 ton/yr
TO INCINERATION
12 hr/day operation
1800lb
150 Ib/hr
r--—-_^. TO AFTERBURNER
AIR SCRUBBER
CO2 COMPRESSOR
90%CaO
2200 Ib
180 Ib/hr
LIME
o
50% CaO
2700 Ib
225 Ib/hr
MAKEUP
LIME
STORAGE
0-*,
LIME
RAPID MIX
Assumptions: 60% solids recovery in furnace
Minimum of 75% purity be weight of
Ca(OH)2 feed to lime rapid mix.
Design criteria in bold type are per
mgd influent wastewater flow
11-62
-------
3. COSTS OF UNIT PROCESSES
-------
Section III - Costs of Unit Processes
3. 1 Cost Determinations
Costs were determined for each unit process depicted in the series of flow
sheets. Capital costs and operation and maintenance costs were developed
based upon unit sizing as determined by standard design criteria, process
loading capacities, solids generation, chemical and energy consumptions and
manpower requirements. The costs generated are not intended to reflect
costs for any particular region of the U.S., but are average values. Local
conditions, variations in wastewater characteristics, and numerous other var-
iables will significantly affect actual costs for specific plants. The costs
presented in this report are therefore not intended as precise values but
for comparing total cost of alternative wastewater treatment systems which
are capable of achieving comparable effluent water quality. Detailed discuss-
ion of the use of the cost-effectiveness data is included in subsequent sections.
The sources of information utilized in obtaining cost information on the various
unit processes are listed in the attached bibliography. In addition to current
literature sources, important cost data were obtained from current consulting
engineering design proposals for both wastewater treatment and sludge
handling systems. These designs propose utilizing many of the advanced unit
processes presented in this report and served as the most recent information
sources for comparing cost data.
III-l
-------
3.2 Costs Included
Total cost for each unit process comprises the sum of the capital, opera-
ting and maintenance costs. Capital costs include:
o Construction cost amortized over 20 years at 5-5/8 percent interest.
o Structures, equipment, pumps and integral piping, and appurtenances
described or implied by the unit process flow sheets.
o Land requirements at $2,000 per acre.
o Engineering, contingencies, and interest during construction at
27 percent.
Operating and Maintenance costs include:
o Annual average equivalent of operating and maintenance costs inclvd-
ing labor, taken at 100 percent utilization of each unit process within
the system throughout the life of the plant.
o All material costs, including chemicals, power and fuel, and other
materials.
A listing of consumable goods and associated costs considered in the unit
processes are presented in Table III-l. All costs utilized are trended to a
common cost level. Capital costs are trended by use of the National Average
Wastewater Treatment Plant Cost Index of 177. 5 for February 1973. Mate-
rial costs were trended using the Wholesale Price Index for Industrial Commo-
dities of 120.0, current for February, 1973. Labor cost, including allowance
for fringe benefits, was taken at $5. 00 per hour. The cost indices used were
made available by the EPA and Department of Labor Statistics office.
Ill-2
-------
The reader is reminded that construction and O&M costs are constantly
changing and since these cost curves were formulated (February 1973), the
National Average Wastewater Treatment Plant Cost Index, the Wholesale
Price Index for Industrial Commodities, the labor rate, the cost of land, and
the Water Resources Council interest rate have changed.
Should the reader desire to modify the cost curves presented herein by
changing one or more of these assumptions, he is directed to Appendix B
of this report where costs equations have been developed with a flexibility
that permits changing various economic parameters, e.g. cost indices,
labor rate, etc.
Ill-3
-------
3. 3 Costs Not Included
Costs are not included for ultimate sludge disposal, yardwork, pump sta-
tions and pipelines for conveyance of wastewater to the treatment plant, outfalls,
the effect of recycle streams where judged insignificant, or for other facilities,
such as garages, administration buildings and laboratories, most of which
would be common to any complete wastewater treatment system. Inclusion of
such common cost is not necessary since the focus of this study is primarily the
comparison of alternative wastewater treatment and sludge handling systems.
3. 4 Cost Curves for Unit Processes
Utilizing the sources coded in the bibliography, total annual costs were deter-
mined, including amortized capital cost and annual operation and maintenance
costs for each wastewater treatment and sludge handling process. This was
accomplished for influent wastewater flows of 1, 5, 20, and 100 MGD. The
total annual cost, annual amortized capital cost and annual operating and main-
tenance cost were then converted to cost in cents per 1000 gallons of treated
influent wastewater, and cost curves were plotted from 1 to 100 MGD for each
process considered. These curves follow at the end of this section.
For reasons discussed in the preceding section, there are several flow sheets
associated -with each unit process. For a given unit process, each flow sheet
defines specific operating conditions inherent to the flow sheet. The condi-
tions specified are sufficiently different to change capital and/or operating and
maintenance costs from those of a similar flow sheet defining the given unit
process under other specific operating conditions. Thus, three curves, one
for total cost, one for operating and maintenance costs, and one for amortized
capital cost have been developed for each flow sheet in Section II.
Each flow sheet and its companion cost curves bear the same identification
number and title.
III-4
-------
3. 5 Factors other than Cost Considered in Selecting Waste-water Treatment
Unit Processes
There are other factors which must be considered in the final selection of
appropriate unit processes for wastewater treatment and sludge handling.
These factors are assessed qualitatively in Table III -2.
3. 6 Calculation of Capital Cost, OfcM Cost, and Total Cost
For example's sake only, the capital cost (in dollars), O&tM cost (in dollars/yr)
and total cost (in dollars/yr) for a 20 MGD conventional primary sedimentation
facility (unit process A-l) are calculated below.
Before embarking on similar calculations, the user of this guide should
realize that its purpose is to make comparative cost analyses of alternative
treatment systems. These calculations are provided for the convenience of
those who wish to use the information contained herein as rough approxima-
tions of capital and O&M costs. Extreme caution should be exercised in
using data in this manner because (1) many costs have not been considered
(See Section 3. 3, Costs Not included), (2) there are wide cost variations
caused by factors unique to any given project, e. g. , site conditions, ^ocal
variations in material and labor costs and different wastewater characteris-
tics, and (3) cost curves were developed with cost indices, interest rate,
and manhour labor rate current for February 1973. (Refer to Section III - 2. )
The reader should obtain current cost indices, labor rate, and interest rate
and utilize the cost equations in Appendix B for more current information.
Ill - 5
-------
CAPITAL COST
/Amortized \
I Capital Costj , I x Q.10 gai x $ x 365 days = /Amortized V _£_
\from curve* / 1000 gal alTy100^ yr [Capital Cost) yr
/Amortized \
| Capital Cost\ x 3650 Q = / Amortized\, $/yr
\from curvely (^Capital Cost/
/Amortized \ $ x pwF (5 5/8%, 20 yrs)2 = Capital Cost, $
(^Capital Cost) yr
Substituting 11. 83 for PWF and summarizing,
/Amortized \
( Capital Cost! x 43179. 5 Q = Capital Cost, $
A from curve ]
/Amo r ti z e d \
Substituting 20 MGD for Q and 0. 8^/1000 gal for J Capital Cost! ,
e /
V from curve
Capital Cost = $690, OOP
1 Although this example uses a value from the capital cost curve for unit process A-l, the reader should calculate
the capital cost by using Appendix B equations with current indices,interest rate, and land cost for a more
current estimate.
2 PWF, present worth factor, is the inverse of the capital recovery factor used in Appendix B of this guide.
For a 20 year amortization period, some present worth factors are:
% interest
5 5/8
5 7/8
6 1/8
PWF
11.83
11.59
11.35
6 3/8 11.13
III-6
-------
O & M COST
fO & M CostX , _ In6
\ , 9 * Q, 10 gal x
ifrom curve I 1000 gal day
100
x 365 days = O&M Cost, $/yr
yr
I
fO & M CostX
from curve )
x 3650 Q - O & M Cost, $/yr
Substituting 20 MGD for Q and 0. 5 9/1000 gal for
/O&M Cost'
from curve
O & M Cost = $36500/yr
Although this example uses a value from the O&cM cost curve for unit process A-l, the reader should
calculate the O&M cost by using Appendix B equations with current indices and labor rate for a more
current estimate.
Ill-7
-------
TOTAL COST
Total cost, $/yr is obtained similarly to O&M Cost, $/yr
Total cost, $/yr = /Total Cost \ x 3650 Q
\from curve/
Substituting 20 for Q and 1. 3 for /Total Cost
\from curve
Total Cost = $94, 900/yr
4
An alternative method of calculating the total cost is to sum the amortized capital cost and O&M costs:
Total Cost = $58,400/yr + $36, 500/yr = $94, 900/yr
This method should be emoloyed when Appendix B equations are used to calculate capital and O&M costs.
III-8
-------
TABLE III-l
PROPERTIES & COSTS OF COMMON WASTE TREATMENT CHEMICALS
& COSTS OF ENERGY
Chemical Name
Formula
Trade Name
Aluminum Sulfate
A12(SO4)3. 14 H2O
Alum
Calcium Oxide
CaO
Quicklime
Calcium Hydroxide
Ca(OH)2
Form
As
Shipped
Bags
Bulk
Liquid
Bulk
Bags
Bulk
Bags
Commercial
Strength
17% A12O3 min.
17% A12O3 min.
8. 3% A12O3
93-98% CaO
72 - 74%
as CaO
Bulk
Density
Lbs/Cu Ft
62 - 67
62 - 67
55 - 60
25 - 35
Market
Price
F.O. B. Plant
$67. 25/ton
$62. 80/ton
$49. 15 /ton
$18. 00-$19. 50/ton
$23. 00-$25. 00/ton
$19. 50-$21. 75/ton
$25. 00-$25. 25/ton
Hydrated Lime
Ferric Chloride
FeCl3
Calcium Hypochlorite
Ca(OCl)2.4 H2O
Chlorine
ci2
Methanol
#2 Fuel Oil
Natural Gas
Electricity
Liquid
Drums
Tank Cars
One Ton Cylinders
Tanks
Sewage Grade
70% available 50 - 53
Chlorine
100%
$4. 00/100 Ibs
$29.80/100 Ibs
$3. 75/100 Ibs
$7.00/100 Ibs
$0. 12/gal.
$0. 65/million Btu
$0. 80/million Btu
$0.015/KWH
III - 9
-------
TABLE III-2 FACTORS OTHER THAN COSTS NORMALLY CONSIDERED ;N SELECTION OF WASTEWATER TREATMENT
AND SLUDGE HANDLING UNIT PROCESSES
Adverse
Land Climatic
Requirements Condition
Ability Ability
to Handle to Handle Industrial
Inlet Flow Influent Quality Pollutants
Variations Variations
Ease of
Reliability of Operation & Occupational Air Waste
Affecting Process the Process Maintenance Hazards Pollution Products
AA-Preliminary Treatment
AB -Pumping
A-Primary Sedimentation
Conventional
With Chemicals
B-Trickling Filters
C-Activated Sludge
Conventional
With Chemicals
D-Dual Media Filters
E-Activated Carbon
F- Two-Stage Lime Treatment
G-Biological Nitrification
I-Ion Exchange
J-Breakpoint Chlorination
K-Ammonia Stripping
L-Anaerobic Digestion
M-Heat Treatment
N-Air Drying
O -De watering
P-Incineration
R-Disinfection
Min.
Min.
Mod.
Min.
Max.
Mod.
Min.
Mod.
Mod.
Max.
Max.
Max.
Min.
Mod.
Mod.
Max.
Mod.
Max.
Min.
Min.
Min.
Good
Freezing Good
Fair
Good
Freezing Good
Fair
Good
Good
Good
Good
Cold Fair
Crtl A IT a i T-
oiu K air
Fair
Good
Cold Fair
Good
Fair
High Good
Rainfall
Fair
Fair
Good
Good
Good
Good
Very Good
Fair
Good
Very Good
Good
Fair
Good
Fair
F_ .• _
air
Good
Good
Fair
Good
Fair
Good
Fair
Good
Good
Min.
Min.
Mod.
Max.
Mod.
Mod.
Max.
Min.
Max.
Min.
Mod.
M—,3
OQ.
Max.
Max.
Min.
Max.
Min.
Min.
Min.
Min.
Max.
Very Good
Very Good
Good
Very Good
Very Good
Good
Good
Very Good
Good
Very Good
Fair
Fair
Good
Very Good
Good
Good
Good
Fair
Good
Very Good
Very Good
Fair
Fair
Very Good
Good
Very Good
Fair
Good
Good
Good
Fair
Fair
Fair
Good
Good
Fair
Good
Fair
Very Good
Good
Fair
Good
Structures
Mech.
Structures
Mech.
Structures
Chemicals
Structures
Structures
Chemicals
Structures
Mech.
Fires
Explosion
Chemicals
Structures
Explosions
Chemicals
Chemicals
Structures
Explosion
Explosion
Gas
-
Chemicals
Explosions
Chemicals
Odors
_
Odors
-
Odors
Regenerant
Gas
Odor
NH3
Chlorine
Odor
Ammonia
-
Odors
Odors
Grit
Screenings
_
Sludges
Sludges
Sludges
Sludges
Sludges
Backwash
Waste
Spent
Carbon
Excess Sludge
Sludge
Sludge
Waste
Regenerant
*
Ammonia
Sludge CO2
Methane
Sludge Filtrate
Sludge
Sludge Filtrate
Combustion Ash
Products
Chlorine
Odor
*
* Increases effluent total dissolved solids
III - 10
-------
WASTEWATER TREATMENT PROCESSES
COST CURVES
Preliminary Treatment
Pumping
Primary Sedimentation
Trickling Filter
Activated Sludge
Filtration
Activated Carbon
Two Stage Tertiary Lime
Biological Nitrification
Biological Denitrification
Ion Exchange
Breakpoint Chlorination
Ammonia Stripping
Disinfection
AA
AB
A-l thru A-5
B-l thru B-3
C-l thru C-8
D
E
F-l thru F-2
G-l thru G-4
H
I
J
K
R
III-12
111-13
III-14 thru III-l8
III-19 thru III-21
III-22 thru III-29
III-30
111-31
III-31A thru £11-32
III-33 thru III-36
III-37
III-38
III-39
III.40
111-41
SLUDGE HANDLING PROCESSES
COST CURVES
Anaerobic Digestion
Heat Treatment
Air Drying
Dewatering
Incine ration
Re calcination
L-l & L-2
M-l & M-2
N-l & N-2
0-1 thru 0-9
P-l thru P-7
Q-l thru Q-3
III-42 thru III-43
IH-44 thru 111-45
III-46 thru III-47
III-48 thru III-56
III-57 thru III-63
III - 64 thru III- 66
III-11
-------
AA. PRELIMINARY TREATMENT
Influent: Raw Wastewater
10.0
100
PLANT CAPACITY - MGD
111-12
-------
AB. RAW WASTEWATER PUMPING
Influent: Effluent from Preliminary Treatment AA
10.0-
9-
8-
7-
6-
5-
k-
C3
O
O
O
1.0-
.9
.8-
.7-
.6
.5
o
o
.3
.2-
0.1-
56789
10
PLANT CAPACITY - MGO
56789
100
III- 13
-------
A-1. PRIMARY SEDIMENTATION - CONVENTIONAL
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
10.0
0.1
100
PLANT CAPACITY - MGO
III- 14
-------
A-2. PRIMARY SEDIMENTATION - TWO-STAGE LIME ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
10.0-
9-
8-
7-
6-
z
o
o
o
o
1.0-
.9
.8-
z
UJ
CO
o
.6-
.5-
.3-
.2-
0.1-
56789
10
PLANT CAPACITY - MGD
56789
100
III- 15
-------
A-3. PRIMARY SEDIMENTATION - SINGLE-STAGE LIME ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
10
0.1
100
PLANT CAPACITY - MGD
III- 16
-------
100
A-4. PRIMARY SEDIMENTATION - ALUM ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
100
PLANT CAPACITY - MGD
III- 17
-------
100
A-5. PRIMARY SEDIMENTATION - FeCI3 ADDITION
Influent: Effluent from Preliminary Treatment AA or
Raw Wastewater Pumping AB
100
PLANT CAPACITY - MGD
III- 18
-------
B-1. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation - Conventional A-1
10.0
0.1
100
PLANT CAPACITY - MGD
III- 19
-------
B-2. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation — Single-Stage Lime Addition A-3
10.0-
9-
8-
7-
6-
to
z
o
o
o
o
1 .0-
?, .9
.8-
.7-
.6
.5
.4
.3
o
o
.2
0.1-
56789
10
PLANT CAPACITY - MGD
56789
100
III- 20
-------
B-3. TRICKLING FILTER
Influent: Effluent From Primary Sedimentation — Alum or FeClg Addition A-4 or A-5
10.0-
00
z
o
-------
C-1. ACTIVATED SLUDGE - CONVENTIONAL
Influent: Effluent from Primary Sedimentation — Conventional A-1
100
CO
2
O
O
O
O
CO
O
100
PLANT CAPACITY - MGD
III- 22
-------
C-2. ACTIVATED SLUDGE
Influent: Effluent from Primary Sedimentation - Single-Stage Lime Addition A-3
100
TOO
PLANT CAPACITY - MGD
III- 23
-------
C-3. ACTIVATED SLUDGE
Influent: Effluent from Primary Sedimentation — Alum or FeClg Addition A-4 or A-5
100
to
z
o
O
O
O
<_>
I
00
c
100
PLANT CAPACITY - MGD
III- 24
-------
C-4. ACTIVATED SLUDGE + ALUM ADDITION
Influent: Effluent from Primary Sedimentation — Conventional A-1
100
o
o
o
I/)
o
o
100
PLANT CAPACITY - MGO
III- Z5
-------
C-5. ACTIVATED SLUDGE - FeCI3 ADDITION
Influent: Effluent from Primary Sedimentation - Conventional A-1
100
I/O
z
o
o
o
o
I/O
o
-------
C-6. ACTIVATED SLUDGE - HIGH RATE
Influent: Effluent from Primary Sedimentation - Conventional A-1
100
100
PLANT CAPACITY - MGD
111-27
-------
C-7. ACTIVATED SLUDGE - HIGH RATE + ALUM ADDITION
Influent: Effluent from Primary Sedimentation - Conventional A-1
100
00
2
O
O
O
O
100
PLANT CAPACITY - MGD
III- 28
-------
C-8. ACTIVATED SLUDGE - HIGH RATE + FeCI3 ADDITION
Influent: Effluent from Primary Sedimentation — Conventional A-1
100
100
PLANT CAPACITY - MGD
111-29
-------
100
00
z
o
o
o
o
l/l
o
D. FILTRATION
Influent: Effluent from Primary Sedimentation — Two Stage Lime Addition
A-2
Activated Sludge — Alum or FeClg Addition
C-4 or C-5
Two Stage Tertiary Lime Treatment
F-1 or F-2
Trickling Filter B-2, B-3
Activated Sludge C-2, C-3
Biological Nitrification G-1, G-2, G-3, G-4
Biological Denitrification H
Breakpoint Chlorination J
Ammonia Stripping K
100
PLANT CAPACITY - MGD
III - 30
-------
E. ACTIVATED CARBON
Influent: Effluent from Filtration D
100
100
PLANT CAPACITY - MGD
III - 31
-------
F-1. TWO-STAGE TERTIARY LIME TREATMENT
Influent: Effluent from Trickling Filter System B-1
10.0-
9-
8-
7-
6-
co
z
o
o
o
o
o
1.0-
.9
.8
.7-
I-
1/1 ,
o .6
.5
.3
.2
0.1-
56789
10
PLANT CAPACITY - MGD
56789
100
III-31 A
-------
F-2. TWO-STAGE TERTIARY LIME TREATMENT
Influent: Effluent from Conventional Activated Sludge C-1
10.0
0.1
100
PLANT CAPACITY - MGD
III- 32
-------
G-1. BIOLOGICAL NITRIFICATION
Influent: Effluent from High Rate Activated Sludge C-6
100
O
O
O
100
PLANT CAPACITY - MGD
III- 33
-------
G-2. BIOLOGICAL NITRIFICATION
Influent: Effluent from Trickling Filter System B-1
100
GO
z
O
O
O
O
GO
O
TOO
PLANT CAPACITY - MGD
III - 34
-------
100
G-3. BIOLOGICAL NITRIFICATION
Influent: Effluent from Primary Sedimentation-Single Stage Lime Addition
Primary Sedimentation — Alum or FeCI3 Addition
A-4 or A-5
o
o
o
CO
o
o
100
PLANT CAPACITY - MGO
III- 35
-------
100
G-4. BIOLOGICAL NITRIFICATION
Influent: Effluent from Primary Sedimentation — 2 Stage Lime Addition A-2
or High Rate Activated Sludge + Alum or FeClg Addition C-7 or C-8
00
z
o
o
o
o
o
oo
O
O
100
PLANT CAPACITY - MGD
III- 36
-------
H. BIOLOGICAL DENITRIFICATION
Influent: Nitrification ProcMi Effluent
G-1
G-2
G-3
G-4
IOC-
8-
7-
6-
5-
4-
z
o
o
o
o
o
10-
9
8
7-
6
oo
o
o
56789
10
PLANT CAPACITY - MGD
111-37
56789
100
-------
TOO
I. ION-EXCHANGE
Influent: Filtration - Effluent
D
Activated Carbon Treatment Effluent
E
100
PLANT CAPACITY - MGD
III-3 8
-------
100
J. BREAK POINT CHLORINATION
Influent: Effluent from A-2. B-1. B-2. B-3. C-1, C-2,
C-3, C-4. C-5. F-1, F-2
100
PLANT CAPACITY - MGD
rn-39
-------
K. AMMONIA STRIPPING
Influent: Effluent from First Stage of Two Stage Tertiary Lime Treatment F-1 or F-2
100
100
PLANT CAPACITY - MGD
III- 40
-------
R. DISINFECTION
Influent: Any Process Effluent
10.0
0.1
100
PLANT CAPACITY - MGD
III- 41
-------
L-1. ANAEROBIC DIGESTION
Sludge Influent: Primary Sedimentation - Conventional plus Trickling Filter
A-1 + B-1
Primary Sedimentation - Conventional plus Activated
Sludge - Conventional
A-1 + C-1
Primary Sedimentation - Conventional plus Activated
Sludge - High rate
A-1 + C-6
10.0-
C5
O
O
o
z
UJ
CJ
1 .0-
LU Q
.8
.7
00 ,
O .6
.5
.2
0.1-
56789
10
PLANT CAPACITY - MGD
56789
100
III- 42
-------
L-2. ANAEROBIC DIGESTION
Sludge Influent: Primary Sedimentation — Conventional and Activated Sludge
or High Rate Activated Sludge — Alum or Fed3 Addition
A-1 + C-4 or C-5
A-1 + C-7 or C-8
Primary Sedimentation — Alum or Fed3 Addition + Activated
Sludge or Trickling Filter
A-4 + B-3 or C-3
A-5 + B-3 or C-3
10.0-
9-
8-
7-
6-
O
O
O
»/>
»—
1.0-
uj q.
o •J
.8
s -6
.5
.k-
.3
.2
o.i-
56789
10
PLANT CAPACITY - MGD
111-43
56789
100
-------
M-1. HEAT TREATMENT
Sludge Influent: Biological Primary + Secondary — Conventional or High rate
A-1 + B-1
A-1 + C-1
A-1 + C-6
10.0-
9-
8-
7-
6-
CJ
o
o
o
1 .0-
.9
.8-
.7-
.6-
.5
.k-
.3
o
I
.2
0.1-
56789
10
PLANT CAPACITY - MGD
111 - 44
56789
100
-------
M-2. HEAT TREATMENT
Sludge Influent: Primary Sedimentation + Activated Sludge or High Rate Activated Sludge
A-1 + C-4 or C-5 — Alum or FeCI3 Addition
A-1 + C-7 or C-8
Primary Sedimentation — Alum or FeClg Addition + Activated Sludge
or Trickling Filter
A-4 + B-3 or C-3
A-5 + B-3 or C-3
0.1
100
PLANT CAPACITY - MGD
111 - 45
-------
N-1. AIR DRYING
Sludge Influent: Digested Primary + Secondary — Conventional L-1
10.0-
9-
8-
7-
6-
O
O
o
1 .0-
.9
.8-
.7-
.6-
.5
O&M
CAPITAL
<_>
I
.3-
.2
0.1-
56789
10
PLANT CAPACITY - MGD
III- 46
56789
100
-------
N-2. AIR DRYING
Sludge Influent: Digested Primary + Secondary (Alum or FeClg Addition) L 2
10.0-
9-
8-
7-
6-
I I
CO
z
o
O
O
O
1 .0-
: .9
.8-
.7-
.6
.5
CO
o
o
.3-
.2
0.1-
H—h
56789
10
PLANT CAPACITY - MGD
56789
100
III- 47
-------
O-1. DEWATER ING
Sludge Influent: Primary + Secondary — Conventional or High rate
A-1 + B-1
A-1 + C-1
A-1 + C-6
10.0
0.1
100
PLANT CAPACITY - MGD
III- 48
-------
O-2. DEW ATE RING
Sludge Influent: Primary-Conventional + Secondary-Alum or FeCI3 Addition
A-1 + C-4 or C-5
A-1 + C-7 or C-8
Primary-Alum or FeCI3 Addition + Secondary
A-4 + B-3
A-4 + C-3
A-5 + B-3
A-5 + C-3
10.0-
9-
8-
7-
6-
C3
O
o
o
1 .0-
.9
.8
.7-
.6
.5
.V
.3-
.2
0.1-
56789
10
PLANT CAPACITY - MGD
III - 49
56789
100
-------
O-3. DEWATERING
Sludge Influent: Primary Sedimentation - Two Stage Lime Addition A-2
10.0
0.1
PLANT CAPACITY - MGD
III- 50
100
-------
10.0
O-4. DEWATERING
Sludge Influent: Primary Sedimentation — Single Stage Lime Addition
+ Trickling Filter or Activated Sludge
A-3 + B-2
A-3 + C-2
100
PLANT CAPACITY - MGD
III- 51
-------
O-5. DEWATERING
Sludge Influent: Digested Primary + Secondary — Conventional (L-1)
10.0
0.1
100
PLANT CAPACITY - MGO
III - 52
-------
O-6. DEWATERING
Sludge Influent: Digested Primary + Secondary (Alum or FeCl3 Addition) (L-2)
10.0
0.1
56789
10
PLANT CAPACITY - MGD
III- 53
100
-------
10.0
0.1
O-7. DEWATERING
Sludge Influent: Two-Stage Tertiary Lime Treatment F-1
F-2
100
PLANT CAPACITY - MGD
III- 54
-------
0-8. DEWATERING
Sludge Influent: Heat-Treated Primary + Secondary — Conventional M-1
10.0
0.1
100
PLANT CAPACITY - MGD
III-55
-------
O-9. DEWATERING
Sludge Influent: Heat Treated Primary + Secondary (Alum or FeCl3 Addition) M-2
10.0
0.1
100
PLANT CAPACITY - MGD
III-56
-------
P-1. INCINERATION
Sludge Influent: Dewatered Primary + Secondary - Conventional 0-1
10.0-
CO
z
o
CJ
o
o
o
1 .0
.9
.8
.7
.6
.5
.3
.2
oo
O
CJ
0.1-
56789
10
PLANT CAPACITY - MGD
III- 57
56789
100
-------
P-2. INCINERATION
Sludge Influwit: Dawatered Primary + Secondary
(Alum or FeCl3 Addition) 0-2
10.0-
9-
8-
7-
6-
o
o
o
o
£1.0-
UJ O .
!s-
i
r- -7'
S -6
.5
.3
.2
0.1-
56789
10
PLANT CAPACITY - MGD
56789
100
III- 58
-------
P-3. INCINERATION
Sludge Influent: Primary Sedimentation - Two-Stage Lime Addition O-3
100
100
PLANT CAPACITY - MGD
III- 59
-------
P-4. INCINERATION
Sludge Influent: Dewatered Primary Sedimentation - Single Stage Lime Addition 0-4
100
100
PLANT CAPACITY - MGD
III- 60
-------
P-5. INCINERATION
Sludge Influent: Dewatered Tertiary Two-Stage Lime Treated + Dewatered Primary and
Secondary — Conventional
O-7 + O-1
10.0-
9-
8-
7-
6-
5-
k-
o
-------
P-6. INCINERATION
Sludge Influent: Dmmtered Hert-TrMted Prirmry + Secondary - Conventional O-8
10.0-
9-
8-
7-
6-
o
o
o
:i.O-
! .9
.8-
.7-
.6-
.5
co
O
.3-
.2
0.1-
56789
10
PLANT CAPACITY - MGO
111- 62
56789
100
-------
P-7. INCINERATION
Sludge Influent: Dewatered Heat-Treated Primary + Secondary (Alum + FeCI3 Addition) O-9
100
TOO
PLANT CAPACITY - MGD
III- 63
-------
Q-1. RECALCINATION
Influent: Dewatered Sludge From Two-Stage Lime Addition in Primary
(0-3)
100-
9-
8-
7-
6-
2
O
C3
O
O
O
10-
9
8
7
6
5
56789
10
PLANT CAPACITY - MGD
56789
100
III-6 4
-------
100
Q-2. RECALCINATION
Influent: Dewatered Sludge from Single Stage Lime Addition in Primary
Sedimentation + Sludge From Secondary Treatment
(0-4)
100
PLANT CAPACITY - MGD
III- 65
-------
100
Q-3. RECALCINATION
Influent: Dewatered Sludge From - Two-Stage Tertiary Lime Treatment
(0-7)
100
PLANT CAPACITY - MGD
III- 66
-------
4. COMBINING UNIT PROCESSES FOR
VIABLE WASTEWATER TREATMENT SYSTEMS
-------
Section IV-Combining Unit Processes for Viable Waste-water Treatment Systems
4. 1 - Definition
The unit processes described by the flow sheets appended to Section II can
be combined in a variety of logical sequences to make up viable wastewater
treatment and sludge handling systems. Varying degrees of effuent quality
can be achieved, depending upon the choice of combinations.
4. 2 - Combined Unit Process Diagrams
Logical combinations of the unit processes are shown by means of Diagrams
IV-1 and IV-2. The combinations are limited to those which by experience
have proven to be effective in achieving intended levels of treatment.
Diagram IV-1 presents combinations of wastewater treatment unit processes
and Diagram IV-2 presents sludge handling unit process combinations.
Unit processes are given letter and numerical designations, the same as
noted on the unit process flow sheets in Section II and cost curves in
Section III. Descriptions of unit processes are included in the left hand
column of the Diagrams. Unit processes in Diagram IV-1 are connected by
lined pathways to form various complete wastewater treatment systems.
Generally, by beginning at the innermost unit processes (primary
sedimentation with or without chemical addition), and proceeding radially
outward along the various pathways to subsequent unit processes,
progressively higher levels of treatment are noted. The pathways need
not be followed to the end, but can be terminated at various intermediate
IV-1
-------
processes depending upon the degree of treatment desired. It is impor-
tant to note that, although disinfection has not been shown on Diagram IV-1,
it has been assumed to be the final unit process in any treatment system.
The effluent quality expected from each system is shown on the same cir-
cumferential line of the last unit process preceding disinfection. Each
unit process which could logically precede disinfection in a combined sys-
tem is located on a circumferential line. In addition to disinfection, pre-
liminary treatment and raw wastewater pumping have not been shown on
Diagram IV-1 for reasons explained in Section V.
Alternative sludge handling systems are presented in Diagram IV-2. The
inner portion of this diagram is similar to Diagram IV-1, but depicts only
unit processes which produce sludges. The outer portion of the diagram
shows combined sludge handling systems capable of handling the sludges
produced. By following the pathways outward, alternative systems can
be found which are capable of handling sludges produced by unit processes
in each wastewater treatment system. The pathways can be terminated
at intermediate processes as in Diagram IV-1. The final disposal require-
ments or alternatives are shown in the upper portion of the diagram, lo-
cated on the same circumferential line of the final sludge handling unit
process in any system chosen.
IV- 2
-------
A detailed description of how to use these two diagrams in comparing
cost-effectiveness of alternative wastewater treatment systems, including
three examples, follows in Section V.
IV - 3
-------
WASTEWATER TREATMENT UNIT PROCESSES
AA. Preliminary Treatment
Influent: Raw wastewater
AB.
A.
C.
Raw Wastewater Pumping
Influent: Effluent from AA
Primary Sedimentation
Influent: Effluent from AA or AB
A-1 Conventional
A-2 Two-Stage Lime Addition
A-3 Single Stage Lime Addition
D. Filtration
Influent: Effluent from A-2, B-2, B-3, C-2,
C-3, C-4, C-5, F-1 or F-2
G-1.G-2, G-3, G-4, H,J, K
E. Activated Carbon
Influent: Effluent from D
F. Two-Stage Tertiary Lime Treatment
F-1 Influent: Effluent from B-1
F-2 Influent: Effluent from C-1
THIS PAGE INTENTIONALLY
BLANK
D- I IIIMUCIIL. (-IIIUCIII IIUIII |-\- I
B-2 Influent: Effluent from A-3
B-3 Influent: Effluent from A-4 or A-5
Activated Sludge
C-1 Conventional
Influent: Effluent from A-1
C-2 Conventional
Influent: Effluent from A-3
C-3 Conventional
Influent: Effluent from A-4 or A-5
C-4 Alum Addition
Influent: Effluent from A-1
C-5 FeCI3 Addition
Influent: Effluent from A-1
C 6 High Rate
Influent: Effluent from A-1
C-7 High Rate & Alum Addition
Influent: Effluent from A-1
C-8 High Rate & FeClg Addition
Influent: Effluent from A-1
ication
Effluent from C-6
Effluent from B-1
u-j miiuinu. effluent from A-3, A-4 or A-5
G-4 Influent: Effluent from A-2,C-7 or C-8
Biological Denitrification
Influent: Effluent from G-1, G-2, G-3 or G-4
Ion Exchanges
Associated with A-2, B-2, B-3, C-2, C-3, C-4,
C-5, F-1, or F-2
Breakpoint Chlorination
Influent: Effluent from A-2, B-1, B-2, B-3, C-1, C-2,
C-3, C-4, C-5, F-1 or F-2
K.
R.
Ammonia Stripping
Influent: Effluent from F-1 or F-2
Disinfection
Influent: Effluent from any treatment process
-------
NOTES
1. All effluents
are disinfected
and contain no
more than 200 fe-
cal coliform per 100
ml.
2. Disinfection, preliminary
treatment, and raw wastewater
pumping have not been shown on
the diagram because, being common
to all or none of the treatment systems
producing a given effluent, they exert no
influence on the choice of one system over
another. To determine the total liquid process
cost, however, they must be considered.
DIAGRAM 1V-1
COMBINING UNIT PROCESSES FOR
WASTEWATER TREATMENT SYSTEMS
-------
SLUDGE HANDLING UNIT PROCESSES DESCRIPTION
L.
M.
N.
O.
Q.
Anaerobic Digestion
L-l Sludge Influent: Generated from A-l+B-1, C-l or C-6
L-2 Sludge Influent: Generated from A-l+C-4, or C-5, or C-7, or Ci
A-4+B-3 or C-3, A-5+B-3 or C-3 :
Heat Treatment
M-l Sludge Influent: Generated from A-l+B-1, C-l or C-6
M-2 Sludge Influent: Generated from A-l+C-4 or C-5, or C-7, or C -
A-4+B-3 or C-3, A-5+B-3 or C-3
Air Drying
N-l Sludge Influent:
N-2 Sludge Influent:
Dewatering
O-l Sludge Influent:
O-2 Sludge Influent:
O-3
O-4
O-5
0-6
O-7
0-8
O-9
Sludge Influent:
Sludge Influent:
Sludge Influent:
Sludge Influent:
Sludge Influent:
Sludge Influent:
Sludge Influent:
Incineration
P-l Influent Sludge:
P-2 Influent Sludge:
P-3 Influent Sludge:
P-4 Influent Sludge:
P-5* Influent Sludge:
P-6 -Influent Sludge:
P-7 Influent Sludge:
Effluent Sludge from L-l
Effluent Sludge from L-2
Generated from A-l+B-1, C-l or C-6 ,
Generated from A-l+C-4 or C-5, or C-7, or C-;
A-4+B-3 or C-3, A-5+B-3 or C-3
Generated from A-2
Generated from A-3+B-2 or C-2
Effluent Sludge from L-l
Effluent Sludge from L-2
Generated from F-l or F-2
Effluent Sludge from M-l
Effluent Sludge from M-2
Effluent Sludge from O-l
Effluent Sludge from O-2
Effluent Sludge from O-3
Effluent Sludge from O-4
Effluent Sludge from O-7+O-1
Effluent Sludge from O-8
Effluent Sludge from O-9
Recalcination (includes chemical storage & feeding)
Q-l Sludge Influent: Effluent Sludge from O-3
Q-2 Sludge Influent: Effluent Sludge from O-4
Q-3 Sludge Influent: Effluent Sludge from O-7
#Note - Use pathway from 0-1 to P-5
only when F-l or F-2 is included
in the complete system.
l;*Sludge leaving this process maybe
recalcined in part. If this is the case,
the remainder may be either incinerated
or hauled to disposal.
-------
HAUL ASH TO LAND DISPOSAL AND
' REL'SE RECALCINED LIME.
HAUL ASH TO LAND DISPOSAL
HAUL TO LAND DISPOSAL
HAUL TO LAND DISPOSAL
PIPE OR HAUL TO LAND DISPOSAL
PIPE OR HAUL TO LAND DISPOSAL
SLUDGE PRODUCING
WASTEWATER TREATMENT
DIAGRAM IV-2
COMBINING UNIT PROCESSES
FOR SLUDGE HANDLING SYSTEMS
-------
5. DETERMINING COST EFFECTIVENESS
OF WASTEWATER TREATMENT SYSTEMS
-------
Section V-Determining Cost-Effectiveness of Wastewater Treatment Systems
5. 1 - Procedure for Use of Diagrams IV-1 and IV-2 and Comparing
Alternative Systems Costs
Diagrams IV -1 and IV-2 can be used to easily find all logical unit process
combinations to achieve a specific effluent quality, and to identify alternative
sludge handling schemes. The general procedure for using the diagrams
followed by three specific examples are presented below.
The following procedure is intended to simplify the use of the diagrams.
Step 1 Find the desired or required effluent quality located on the
circumferential lines in the upper center portion of Diagram IV-1.
Step 2 Remembering that disinfection is usually the final unit process in any
system, follow the circumferential line on which the desired
effluent quality is located and stop at each unit process located
on the line. These are the unit processes that could precede
disinfection in a treatment system producing the desired effluent
quality chosen. Also remember that preliminary treatment is
the first process in any treatment system. If needed, raw
wastewater pumping would follow preliminary treatment. Dis-
infection, preliminary treatment, and raw wastewater pumping
have not been shown on the diagram because, being common to
all or none of the treatment alternatives producing a given effluent,
V-l
-------
they exert no influence on the choice of one system over another.
However, they must be included in the determinations of costs
associated with each treatment system.
Step 3 Beginning with each of the processes on the circumference,
follow the lined pathways toward the center of diagram noting
each unit process comprising the system until reaching the unit
process (A series) located nearest the center of the diagram.
Include all possible pathways. Some pathways may branch, in
which case more than one system would be obtained from a single
beginning pathway. Make note of all possible systems that will
give the required effluent. The total number of systems that
should be found for each effluent quality are shown in parentheses
beside the effluent qualities.
Step 4 Proceed to Diagram IV-2. For each system selected, certain
processes generate waste sludges. Find (on Diagram IV-2) the
sludge-producing unit process combinations which correspond to
those systems chosen from Diagram IV-1.
Step 5 Follow the pathways to the sludge handling unit processes, making
note of alternative sludge handling systems for each wastewater
treatment system chosen. Ultimate disposal requirements are
V-2
-------
shown in the upper center portion of the diagram on the circum-
ferential line associated with the last sludge handling unit process
considered for each complete system. It should be noted in this
diagram that some sludge handling systems will be common to
several wastewater treatment unit process combinations. This
is shown by converging pathways leading from the wastewater
treatment unit processes to the sludge handling unit processes.
Step 6 After all unit processes associated with each complete wastewater
treatment and sludge handling systems are listed, the total
O & M, and amortized capital cost of each unit process can be found
in the cost curves in Section III for plant sizes of 1-100 MGD. The
total cost of each system can be found by adding all unit process
total costs. Cost comparisons of alternative systems can then be
made.
Although each system will generally meet the effluent quality listed on the
same circumferential line of the last unit process in each system, some
systems will produce slightly better effluent than others. Therefore the effluent
values listed on Diagram IV-1 are shown as average values or narrow ranges of
values. To determine the specific effluent value that can be achieved by specif-
ic processes or systems, the unit process flow diagrams in Section II should
be referred to.
V-3
-------
5. 2 - Examples of Comparing Cost- Effectiveness of Complete Wastewater
Treatment Systems
Three examples are presented to illustrate the use of the diagrams and cost
curves to determine cost-effectiveness of various systems. The examples
include wastewater treatment systems which must achieve the following
effluent wastewater quality:
1. BOD §30 mg/1 SS S 35 mg/1, no P or N removal required
2. BOD §5 mg/1 SS s3 mg/1, P gl mg/1, no N removal required
3. BOD ^ 5 mg/1 SS §3 mg/1, P Slmg/1, total N 53 mg/1
The examples assume the use of similar sludge handling systems where possible
and recalcination of lime sludges. Costs are based on systems which must
treat a 20 MGD influent wastewater flow.
Example 1 The step-by-step procedure to follow in the example is as follows:
Step 1 Locate (on Diagram IV -1) the effluent quality that meets
the requirement. For this example, it is assumed pre-
liminary treatment, pumping, and disinfection are needed.
Processes which meet the BOD and SS criteria and include
P removal need not be considered. The effluent quality on
»
the second circumferential line from the center meets the
criteria, and it is noted from the number in parentheses
that two systems should be found which meet the required
effluent quality.
V-4
-------
Step 2 Proceed around the circumference stopping at C-l and B-l.
These processes would precede disinfection in each system.
Step 3 Following the lined pathways toward the center of the
diagram, B-l and C-l both lead to A-l. Therefore, the
two systems are A-l + B-l and A-l + C-l. As noted
from the process descriptions in the righthand column,
these are conventional primary sedimentation + trickling
filter and conventional primary sedimentation + activated
sludge processes, respectively. Preliminary treatment
AA, pumping AB, and disinfection R are common to both
systems and consequently will not influence the choice of
one system over the other. These costs, however, must
be included in determining total liquid processing costs.
Step 4 Proceed to Diagram IV-2. Locate the two wastewater
treatment systems A-l + B-l and A-l + C-l. The
presence of both unit processes in Diagram IV-2 compris-
ing the two systems indicates that each unit process pro-
duces waste sludge.
Step 5 Follow the pathways from both systems to the outer section
of the diagram. The two pathways converge indicating that
the sludges generated by the two systems are of similar
quantity and can be handled by common systems. Follow-
ing the pathways further shows that four systems are
capable of handling the sludges: L- 1 + N-1 (anaerobic
V-5
-------
digestion + air drying), L-l +0-5 (anaerobic digestion +
dewatering), M-l 4- O-8 + P-6 (heat treatment + dewater-
ing + incineration), and O-l + P-l (dewatering + incineration).
Step 6 The total, amortized capital, and O & M costs for each unit
process comprising each system can be taken from the
cost curves in Section III and added to give total waste-
water treatment costs and sludge handling costs. Total
costs have been determined for each treatment system
while the most cost-effective system has been broken
down into Q^ M and amortized capital costs.
The example is shown in Table V-l. The costs of preliminary treatment AA, raw
wastewater pumping AB, and disinfection R are common to both possible liquid
systems. Adding these costs to A-l + B-l and A-l + C-l, the table shows that sys-
tem 1 costs 11.0^/1000 gallons of influent and system 2 costs 9.3^/1000 gallons.
The least cost sludge handling system is L-l + O-5, costing 2.4^/1000 gallons.
Therefore, the most cost-effective system would contain (AA 4- AB + A-1+B-1+R)
+ (L-l + O-2) and cost 11. 7 £/1000 gallons. Often, factors other than cost (such as
those listed in Table III-2) .might result in the selection of a less cost-effective
system. Also, the cost of ultimate disposal of sludge or ash will vary depending
upon sludge characteristics and quantities involved and can influence the selection
of sludge handling and wastewater treatment alternatives.
Although the following two examples involve many more alternatives, the procedure
remains the same.
V-6
-------
TABLE V-l
EXAMPLE NO. 1
20 MGD Wastewater Treatment Plant Design for
BOD and SS Removal Only
Trfn .. ^ T, (BOD (mg/1) 30 P(mg/l) 9
Effluent Quality fss(rng/1) 35 TN(mg/1)30
(A) Wastewater Treatment Process Combinations and
Liquid Process Cost (Total Annual Cost in Cents per 1000 gallons)
1 2
Process
C-l
A-l
AA
AB
R
Cost
5.7
1 .3
0.7
2.2
1 .1
Process Cost
B-l 4.0
A-l 1.3
AA 0.7
AB 2.2
R 1.1
Subtotal 11.0 9.3
(B) Sludge Treatment Process Combinations
(Both liquid process sludges will require same kind of treatment.)
Sludge Process Cost
(Total Annual Cost in Cents per 1000 gallons influent)
Process
L-l
N-l
_
atal
Cost
0. 7
2.4
-
IT
Process
M-l
0-8
P-6
Cost
2.1
1. 4
2. 2
5. 7
Process
L-l
0-5
-
Cost
0. 7
1.7
-
zTT
Process
0-1
P-l
-
Cost
2.1
2.6
-
4.7
Use 2.4 cents/1000 gallons for sludge treatment process, but cost of sludge hauling and
disposal on land must be included for complete cost-effective comparison.
(C) Total Annual Cost in Cents per 1000 gallons.
Process No. 1 11.0+2.4 = 13.4
Process No. 2 9.3 + 2.4 = 11 .7
(D) O&M Cost and Amortized Capital Cost of the Most Cost-Effective
System in Cents per 1000 gallons:
Most Cost-Effective System: (AA + AB + A-l + B-l + R) + (L.-1 + O-5)
O&M Costs (from Cost Curves): (0.4 + 0.5 + 1.1+0.9)+ (0.2 + 1.2)
Total O&M Cost: 3.4+1.4 = 4.8
Amortized Capital Cost: (0.3 + 1.7 + 0.8 + 2.9 + 0.2) + (o.5 + 0.6)
(From. CostCurves)
Total Amortized Capital Cost: 5.9+1.1 =7.0
V-7
-------
Example 2 The steps in this example are summarized below. The effluent
which meets the requirements can be located on the sixth circum-
ferential line from the center. Preliminary treatment and disin-
fection are included. Eleven possible systems exist, as noted from
the number in parentheses. Starting from the unit processes
located on that circumferential line, the eleven systems can be
found which meet the desired effluent requirement by tracing the
pathways into the center of the diagram. Proceeding to Diagram
IV-2, the sludge producing unit processes associated with each
system can be found, and corresponding sludge handling systems
noted. For this example, only dewatering + incineration or
recalcination where lime sludges are present are considered.
Therefore, other possible alternative sludge handling systems are
not considered for each total system. This example is presented
in Table V-2. The unit process costs were found from the cost
curves, totaled for each complete system, and recorded in
Table V-2. The most cost-effective system combines (AA + A-3 +
B-2 + D + E + R) + (O-4 +Q-2), or namely preliminary treatment,
primary sedimentation + lime addition, trickling filter, filtration,
activated carbon and disinfection followed by sludge dewatering
+ recalcination. The total cost of the system is 34. 4<£ /1000 gallons.
However, 4 of the 10 other alternative systems were no more than
3^/1000 gallons higher in total cost, as noted in Table V-2.
V-8
-------
The two systems employing F-1 or F-2, tertiary lime treat-
ment and recalcining of lime sludge, were significantly higher
than other alternatives at a total cost of about 47^/1000 gallons.
Example 3 The steps followed in this example are the same as for the first
two examples, but involve selecting more alternative systems.
The required effluent quality is found on the two outer circumfer-
ential lines. In this example, 19 +11 (or 30) alternative systems
are possible, as noted from the numbers in parentheses. All
alternatives are easily found by locating a process on the circum-
ference, and as in the other examples, tracing the pathways to the
center. The 30 alternative systems are listed in Table V-3. Pre-
liminary treatment and disinfection have been added as in Example 2,
Similarly, only dewatering, incineration or recalcining -where lime
sludges are present are considered. Proceeding as in Example 2,
the specific sludge handling processes for each system can be
found. Those specific sludge handling processes associated -with
each system are also listed in Table V-3. The cost can then be
found as in the previous examples. The costs are listed and
totaled for the unit processes in each of the 30 systems. The
most cost-effective system in this example is the same system
found to be most cost-effective in Example 2 with the addition
of ion-exchange, and costing a total of 41.9^/1000 gallons.
However, many of the other alternative systems are very close
to the most cost-effective one.
V-9
-------
It must be emphasized that certain constraints which might be
present in particular cases could eliminate any of the combined
systems from consideration.
V-10
-------
TABLE V-2
EXAMPLE NO. 2
20 MGD Waste-water Treatment Plant Design for BOD, SS, and P Removal With Effluent Polishing
Subtotal
Effluent Quality: BOD (mg/1) 5
SS (mg/1) 3
P (mg/1) 1
TN (mg/1) 30
(A) Waste-water Treatment
1
E
D
A-2
AA
R
Liquid
14.8
4. 3
2.9
0. 7
1. 1
1 23. 8
(B) Sludge
2
E
D
B-2
A-3
AA
R
Process
14.8
4. 3
3. 3
1.6
0. 7
1. 1
25.8
3
E
D
B-3
A-4
AA
R
Cost -
14.8
4.3
3.5
6.0
0. 7
1. 1
30.4
Process Combinations:
4
E
D
B-3
A-5
AA
R
5
E
D
C-2
A-3
AA
R
(Total Annual Cost
14.8
4. 3
3. 5
6.3
0. 7
1. 1
30. 7
14.8
4. 3
4.9
1.6
0.7
1. 1
27.4
6
E
D
C-3
A-4
AA
R
in Cents
14.8
4. 3
4. 8
6.0
0.7
1. 1
31. 7
Treatment Process Combinations Based on
7
E
D
C-3
A-5
AA
R
per 1000
14.8
4. 3
4. 8
6.3
0.7
1. 1
32. 0
8
E
D
C-4
A-l
AA
R
gallons)
14.8
4.3
9.5
1. 3
0.7
1. 1
31.7
Only Dewatering,
9
E
D
C-5
A-l
AA
R
14.8
4.3
9.5
1. 3
0.7
1. 1
31.7
10
E
D
F-l
B-l
A-l
AA
R
14.8
4.3
2.6
4. 0
1.3
0.7
1. 1
28. 8
11
E
D
F-2
C-l
A-l
AA
R
14.8
4. 3
2.6
5.7
1. 3
0. 7
1. 1
30. 5
Incineration and
Recalcination where applicable:
0-3
Q-l
Sludge
4. 5
8. 5
0-4
Q-2
Process
3.4
5. 2
0-2
P-2
Cost -
3.0
5.6
0-2
P-2
0-4
Q-2
(Total Annual Cost
3. 0
3.6
3.4
5. 2
0-2
P-2
in Cents
3. 0
3.6
0-2
P-2
per 1000
3 0
3.6
0-2
P-2
gallons
3. 0
3,6
0-2
P-2
influent)
3. 0
3. 6
0-1
0-7
P-l
Q-3
2. 2
3.7
2. 7
8.8
0-1
0-7
P-l
Q-3
2. 2
3.7
2.7
8.8
Subtotal 13.0 8.6 6.6 6.6 8.6
Total Annual Cost in Cents per 1000 gallons
36.8 34.4 37.0 37.3 36.0
6.6
38.3
6.6
38.6
6.6
38.3
6.6
38. 3
17.4
46.2
17.4
47. 9
V-ll
-------
Subtotal
TABLE V-3
EXAMPLE NO. 3
20 MGD Wastewater Treatment Plant Design for BOD, SS, P and Nitrogen Removal with Effluent Polishing
Effluent Quality
BOD (mg/1) 5
SS (mg/1) 3
P (mg/1) 1
TN (mg/1) 4
(A) Wastewater Treatment Process Combinations:
1 2
E E
D D
H H
G-4 G-4
C-7 C-8
A-l A-l
AA AA
R R
Liquid
14.6 14.6
4. Z 4. Z
3.9 3.9
3.8 3.8
8.5 8.3
1.3 1.3
0.7 0.7
1.1 1.1
38.1 37.9
(B) Sludge
0-2 0-2
P-2 P-Z
Sludge
3.0 3.0
3.6 3.6
3 4
E E
D D
H H
G-3 G-3
A-3 A-4
AA AA
R R
5 6 7 8 9 10 11 12 13 14
EEEEEEEEEE
DDDDDDDDDD
H H I I I I I I I I
G-3 G-4 A-2 B-2 B-3 B-3 C-2 C-3 C-3 C-4
A-5 A-2 AA A-3 A-4 A-5 A-3 A-4 A-5 A-l
AA AA R AA AA AA AA AA AA AA
RR RRRRRRR
15
E
D
I
C-5
A-I
AA
R
16
E
D
I
F-l
B-l
A-l
AA
R
17 18
E E
D D
I J
F-2 A-2
C-l AA
A-l R
AA
R
19
E
D
J
B-2
A-3
AA
R
20
E
D
J
B-3
A-4
AA
R
21
E
D
J
B-3
A-5
AA
R
ZZ
E
D
J
C-2
A-3
AA
R^
23
E
D
J
C-3
A-4
AA
R
24
E
D
J
C-3
A-5
AA
R
Process Cost (Total Annual Cost in Cents per 1000 gallons)
14.6 14.6
4.2 4.2
3.9 3.9
4.2 4.2
1.6 6.0
0.7 0.7
1.1 1.1
30.3 34.7
Treatment
0-4 0-2
Q-2 P-2
14.6 14.6 14.6 14.6 14.6 14.6 14.6 14.6 14.6 14.6
4.2 4.2 4.2 4.2 4.Z 4.2 4.2 4.2 4.2 4.2
3.9 3.9 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.7
4.2 3.8 2.9 3.3 3.4 3.4 4.9 4.8 4.8 9.5
6.3 2.9 0.7 1.7 6.0 6.3 1.7 6.0 6.3 1.3
0.7 0.7 1.1 0.7 0.7 0.7 0.7 0.7 0.7 0.7
1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1
35.0 31.2 31.2 33.3 37.7 38.0 34.9 39.1 39.4 39.1
14.6
4.2
7.7
9.5
1.3
0.7
1. 1
?9. 1
14.6
4.2
7.7
2.6
4.0
1.3
0.7
1. 1
36. Z
14.6 14.6
4. Z 4.2
7.7 1Z.7
Z.6 3.0
5.7 0.7
1.3 1.1
0.7
1. 1
37.9 36.3
14.6
4.2
12. 7
3.3
1.7
0.7
1.1
38. 3
Process Combinations Based On Only Dewatering, Incineration and Recalcination Where
0-2 0-3 0-3 0-4 0-2 0-2 0-4 0-2 0-2 0-2
P-2 Q-l Q-I Q-2 P-2 P-2 Q-Z P-2 P-2 P-2
0-2
P-2
0-1
0-7
P-l
Q-3
0-1 0-3
0-7 Q-l
P-l
Q-3
0-4
Q-2
14.6
4.2
1Z. 7
3.5
6.0
0.7
1.1
4Z.8
14.6
4.2
12. 7
3.5
6.Z
0.7
1. 1
43.0
14.6
4.2
12.7
4.9
1.7
0.7
1.1
39.8
14.6
4.Z
12.7
4.8
6.0
0.7
1. 1
44.1
14.6
4.2
12.7
4.8
6.2
0.7
1. 1
44. 3
Applicable:
0-Z
P-2
0-Z
P-Z
0-4
Q-2
0-2
P-2
0-2
P-2
Process Cost (Total Annual Cost in Cents per 1000 gallons influent)
3.4 3.0
5.2 3.6
3.0 4.5 4.5 3.4 3.0 3.0 3.4 3.0 3.0 3.0
3.6 8.5 8.5 5.2 3.6 3.6 5.2 3.6 3.6 3.6
3.0
3.6
2.2
3.7
2. 7
8.9
2.2 4.5
3.7 8.5
2. 7
8.9
3.4
5.2
3.0
3.6
3.0
3.6
3.4
5.Z
3.0
3.6
3.0
3.6
Subtotal 6.6 6.6 8.6 6.6 6.6 13.0 13.0 8.6 6.6 6.6 8.6 6.6 6.6 6.6 6.6 17.5 17.5 13.0 8.6 6.6 6.6 8.6 6.6 6.6
Total Annual Cost in Cents per 1000 gallons
44.7 44.5 38.9 41.3 41.644.2 44.241.9 44.3 44.643.5 45.7 46.045.7 45.753.755.4 49.346.9 49.4 49.6 48.5 50.7 57.9
-------
25
E
D
J
C-4
A-l
AA
R
26
E
D
J
C-5
A-l
AA
R
27
E
D
J
F-l
B-l
A-l
AA
R
_28_
E
D
J
F-Z
C-l
A-l
AA
R
29
E
D
K
F-l
B-l
A-l
AA
R
30
E
D
K
F-2
C-l
A-l
AA
R
14.6 14.6 14.6 14.6 14.6 14.6
4.
12.
9.
1.
0.
1.
?
7
5
3
7
1
4.
12.
9.
1.
0.
1.
2
7
5
3
7
1
4.
12.
2.
4.
1.
0.
1.
2
7
6
0
3
7
1
4.
12.
-------
APPENDICES
-------
APPENDICES
TABLE OF CONTENTS
Section Page
Introduction to Appendices
Appendix A Unit Process Description A-l
Appendix B Cost Formulae B-l
Appendix C Cost Effectiveness Analysis Guidelines C-l
-------
INTRODUCTION TO APPENDICES
-------
INTRODUCTION TO APPENDICES
These appendices •were prepared to complement the revised edition of
"A Guide to the Selection of Cost-Effective Wastewater Treatment
Systems. " This publication is not intended as a design manual but
as an effective means for making cost comparisons. It allows decision
makers or designers to update and revise the cost curves appearing
in the aforementioned publication to obtain pertinent cost information
on any of the following unit processes.
• Pump Stations
• Preliminary Treatment
• Primary Sedimentation
• Trickling Filtration
• Activated Sludge
• Gravity Filtration
• Granular Activated Carbon
• Two Stage Tertiary Lime Treatment
• Biological Nitrification
• Biological Denitrification
• Ion Exchange
• Breakpoint Chlorination
• Ammonia Stripping
• Disinfection
-------
• Anaerobic Digestion
• Heat Treatment
• Air Drying
• Dewatering
• Incineration
• Recalcination
Appendix A concerns itself with a brief description of each unit process.
Process objectives, major mechanical equipment and intended func-
tions are discussed as are bases for capital and O&M costs.
Cost formulae for each unit process are presented in Appendix B. Each
set of formulae consists of:
• A formula for amortized capital cost
• A formula for fixed operation and maintenance costs
• A formula for operation and maintenance costs which
would be dependent on the quantity of wastewater
treated
The formulae contain economic variables which may be changed as time
and/or specific conditions warrant .
Appendix C is the Cost-Effectiveness Analysis Guidelines (40 CFR part 35)
A list of abbreviations and a bibliography follows Appendix C.
The bibliography includes coding of each data source for one or more
of the following areas of utilization:
• Treatment process characterization
• Process design parameters
-------
• Sludge generation
• Treatment costs
• Sludge handling costs
-------
APPENDIX A UNIT PROCESS DESCRIPTIONS
-------
Appendix A
UNIT PROCESS DESCRIPTIONS
This appendix contains a. brief description for each unit process. Major
topics covered include process objectives, average degress of removal,
major mechanical equipment and intended functions, and bases for capi-
tal and O&M costs. A directory of unit process descriptions follows.
Unit Process Description Page
Preliminary Treatment A-2
Raw Waste water Pumping A-7
Primary Sedimentation A-9
Trickling Filtration A-13
Activated Sludge A-15
Gravity Filtration A-18
Granular Activated Carbon A-19
Two-Stage Tertiary Lime Treatment A-21
Biological Nitrification A-22
Biological Denitrification A-24
Ion Exchange A-25
Breakpoint Chlorination A-26
Ammonia Stripping A-27
Disinfection A-28
Anaerobic Digestion A-29
Heat Treatment A-31
Air Drying A-32
De wate ring A - 34
Incineration A-36
Recalcination A-37
A-l
-------
AA. PRELIMINARY TREATMENT
The major function of preliminary treatment is to render the
waste suitable for processing by subsequent treatment processes.
This treatment includes the removal of large solids, such as rags
and boards, which could damage pumps, and plug lines and in-
organic grit which could cause operation and maintenance problems
within the plant. Because measurement of the raw waste flow rate
is normally made in the same structures as those in -which prelimi-
nary treatment is achieved it is included in this section.
SCREENING
Large solids found in raw waste may be removed by either com-
minution or screening. In the former process the waste passes into
a channel containing a low speed, rotating device equipped with cutting
teeth which shreds the large solids without removing them from the
wastewater. Comminution offers the advantage of being a simple single
step, operation. Unfortunately, because of its continuous operation,
communitor blades tend to dull quickly resulting in a deterioration in
performance. Inadequately shredded materials will commonly build-up
on moving equipment such as aerators, thus severely impeding their
operation. This problem can be minimized, however, by proper main-
tenance.
-------
Bar screens are more commonly used to remove large solids,
especially in larger plants. These screens consist of parallel steel
bars placed at an angle in a channel through which the -waste flows.
The clear openings between the bars vary from 3/4" to 2", depending
upon the specific application. Solids collecting on the bars may be
shredded at the point of collection or removed by automatic or manual
rakes. In the latter case, the collected solids (i.e. screenings)may be either
shredded and returned to the waste stream, incinerated, or buried in a sanitary
landfill. Because such materials are highly putrescible, their prompt
disposal is essential to good operation.
In evaluating the unit cost of preliminary treatment for this study,
the use of bar screens was assumed with screenings being ground and
returned to the plant influent.
FLOW MEASUREMENT
Several methods of flow measurement are available, depending on
the specific application. The most common methods are:
o Venturi meters
o Magnetic flow meters
o Weirs
o Parshall flume (Venturi flume)
The first two devices listed above are used in closed pipes while
the latter two are used in open channels. For measurement of flow in
an open channel, a parshall flume is generally preferred because the loss
in head is usually much less than the loss associated with a weir. Further-
more, a parshall flume when provided at the end of a channel with a parabo-
lic cross section achieves a constant velocity in the channel, which is of a
great advantage when constructed on the down stream side of a screen or
a grit chamber. Thus the functions of flow measurement and velocity control
can be achieved simultaneously.
A - 3
-------
A pa-r shall flume ape rates on the basis of a restriction in the
channel. The dimensions of each particular flume are such that the
flow is a function of the depth of water in the flume. Thus, the rate
of flow can be determined from a single upstream measurement of
depth. Several devices for the measurement of depth are commercially
available. Probably the most trouble free is the so called bubbler tube.
This device consists of a vertical tube in the channel through which air
is passed at a constant flow rate. As the depth of waste in the channel
varies, the pressure required to force the air at the fixed rate to the
bottom of the channel changes. By sensing this pressure, a signal is
obtained which is proportional to flow. This may be either recorded
locally or transmitted to the plant control room.
GRIT REMOVAL
Grit consists of high specific gravity solids, which enter the sewer
system through infiltration and inflow during wet weather and from food
preparation. Grit may consist of sand, gravel, cinders, eggshells,
bone chips, seeds and large organic particles such as food wastes.
It is not normally of concern as a pollutant but should be removed in
order to reduce wear on moving mechanical equipment and to prevent
deposition in pipe lines, channels, and conduits. Removal of grit also
results in significant reduction in the cleaning frequency of a digester where
grit will accumulate.
Grit removal may be achieved by any one of three methods. The first
two methods are gravity and aerated grit chambers which provide short
retention time sedimentation that allows rapidly settling grit to be removed,
while lighter organic solids remain in suspension. Gravity grit cham-
bers are generally horizontal flow chambers designed to provide nearly
constant flow-through velocity. The velocity control may be provided by
A - 4
-------
a series of narrow channels, but more common is some type of control
section, such as a par shall flume, in the outlet channel. In the aerated
grit chamber, an air diffuser located near the bottom of the chamber is
used to induce a helical flow pattern. This provides a positive means of
velocity control thus improving the grit removal efficiency. In both meth-
ods, the grit maybe removed from the chamber either manually or
by means of mechanical collectors, although the former method is limited
to very small plants. Grit from these basins may be disposed of directly
if suitable facilities are available. However, grit washing to remove or-
ganic materials is common practice. After washing, the grit is nonpu-
trescible and may be landfilled or disposed of without creating undesirable
nuisances.
A third method of grit removal is the cyclone .separator. Although-this
method may be used at one of several locations in the pretreatment scheme,
it is commonly used to degrit primary sludge. The grit is settled in a pri-
mary clarifier and pumped along with the primary sludge through a conical
cyclone which uses centrifugal force to separate the grit in a highly efficient
manner. Although this type of degritter results in increased wear on raw
waste and primary sludge pumps, cyclone degritting is finding greater use
because of over-all lower equipment maintenance cost.
For the purposes of this study, a gravity chamber with grit -washing and
separate disposal was assumed.
ITEMS INCLUDED IN COST ESTIMATES
The following items were included in preparation of the cost estimates for
the various sized facilities:
- 5
-------
Capital Cost
\. Flow channels and superstructures
2. Bar racks
3. Grinders (for screenings)
4. Grit chambers
5. Grit handling equipment
6. Par shall flume and flow recording equipment
Major O &c M Costs
The quantity of grit collected and the degree of mechanization of the
preliminary treatment system are the major factors affecting O&M costs.
The cost of grit disposal has not been included but must be considered in
estimating complete O&M costs.
- 6
-------
AB. RAW WASTEWATER PUMPING
Raw wastewater pumping stations are normally designed to provide
sufficient hydraulic head to permit gravity flow through the treatment plant.
In general, it has been found to be more cost-effective to provide sufficient
head in a single pump station than to provide multiple stations of lower
heads within the plant. The exceptions to this are those situations where
site topography prevents plant layout in such a manner that gravity flow can
be readily achieved.
PUMP STATION DESIGN
Pump station design varies widely from plant to plant because of
differences in capacity and head requirements. Generally, these pumping
stations are of relatively low head (10'-40') and high capacity. Various types
of pumps are in common use, but probably the most popular are the open im-
peller centrifugal pumps. Although these are relatively inefficient, they
offer the advantage of being able to pass large solids, an essential feature
of pumps used in this capacity.
An important consideration in the design of raw waste pumping stations
is the diurnal variation of wastewater flow. Because of this variation, the
pumping station must be capable of handling the peak instantaneous flow during
the life of the plant. Further, sufficient standby capacity must be provided to
insure that the maximum flow can be handled even though a portion of the pump-
ing facility is out of service.
For this study, pump capacities •were assigned for estimation of capital
and O & M based on the 24 hour peak flow, while costs of the pumping station
structure were based on ultimate pumping capacity. A typical value of 30' TDH
(total dynamic head) was used to determine horsepower requirements and
power costs.
- 7
-------
2*4 hour Peak Flow Ultimate Pumping Capacity
MGD MOD
1 2
5 7.5
20 30
100 133
ITEMS INCLUDED IN COST ESTIMATES
The following items were included in preparation of the cost estimates,
Capital Cost
1. Pumps and standby units
2. Pumping station structure & auxiliary equipment
3. Electrical Control System
4. Normal earthwork
O&M Costs
Labor requirements will vary with degree of automation, type of pumping
and auxiliary equipment installed. The cost of electric power will have a
major effect on material and supply costs.
A - 8
-------
A. PRIMARY SEDIMENTATION
Gravity settling with or without the addition of chemicals is commonly
used after preliminary treatment for the removal of suspended solids and
BOD. Phosphorus removal may also be accomplished by the addition of
chemical precipitants. For the purpose of this study, primary clarifica-
tion has been divided into four categories depending on the type and mode
of chemicals added to improve removal of suspended solids, BOD and phos-
phorus. Descriptions of each of these categories follows:
Al CONVENTIONAL SEDIMENTATION
Settleable solids represent about 50% of the total suspended matter
and 35% of the BOD contained in domestic sewage. Removal of this material
from the waste by gravity sedimentation serves two important functions.
First, the removal of BOD in the primary settling tanks reduces the load-
ing on the subsequent treatment units. This has the effect of reducing both
the capital and operating costs of such units. Secondly, the removal of the
settleable solids ahead of biological treatment prevents their conversion to
less readily dewaterable secondary sludge. This could have a major bene-
ficial impact on the sizing and operation of sludge thickening and dewatering
equipment.
The purpose of primary sedimentation tanks is to provide a quiescent
condition to allow the solids in the waste to settle. These solids are then
collected from the bottom of the tank and conveyed by scrapers to a trough
or sump for removal as primary sludge.
The design basis of sedimentation tanks is based on the surface loading
rate, expressed as the average rate of wastewater flow per square foot of
tank surface area. Although the suitable loading rate depends on the cha-
2
racteristics of the suspended solids, an average overflow rate of 800 gallons/day/ft
has been found to accomplish complete removal of settleable solids from do-
mestic wastewater. The required surface area of the primary sedimentation
tanks in this study are based on this loading rate.
- 9
-------
A2 TWO STAGE LIME ADDITION
In this modification, lime is rapidly mixed with the first-stage
influent to obtain a minimum pH of 11. The water is stirred in the
first-stage up-flow solids contact clarifier to encourage floe forma-
tion and precipitation. Following settling the water is discharged from
the first-stage unit. Carbon dioxide is added to the water to reduce
the pH in the second-stage to approximately 10, within range of the mi-
nimum calcium carbonate solubility. The water is again flocculated,
settled and discharged. The pH of the process effluent is then neutra-
lized with CO2 or acid.
Solids produced in the first and second-stage units are mechani-
cally collected, thickened and pumped to sludge treatment processes.
The increased efficiency of this process over conventional pri-
mary sedimentation resulting from flocculation of small suspended par-
ticles and precipitation of the oxygen demanding material combined with
other physical chemical unit operations, sometimes eliminates the need
for biological treatment. As much as 80% of the influent BOD, more than
90% of the suspended solids and approximately 90% of the phosphorus can
be removed from the raw waste water by this process. If a higher quality
effluent is required this process can be followed by filtration and activated
carbon to produce an effluent significantly lower in BOD and suspended solids
than conventional secondary effluent.
Advantages of using lime over other chemical agents include
1) more easily dewaterable sludge solids,
2) almost complete destruction of bacteria and viruses,
3) precipitation of nearly all heavy metals, and
4) potential for recovery of much of the lime used.
A major disadvantage is the handling and disposal of large quantities
of lime sludge.
A - 10
-------
A3 SINGLE STAGE LIME ADDITION
If a high degree of phosphorus removal is not required, and
the wastewater composition is suitable, single-stage lime treatment
may be satisfactory. This process is similar to the two stage system
previously described. In this case, however, a pH of about 10 is used
to promote maximum precipitation of calcium from the wastewater in
one step. The up-flow solids contact clarifiers are essentially iden-
tical to those used in the two stage process.
Because of the lower pH used this modification requires significantly
less lime and consequently produces less sludge than the two stage process.
These advantages, however, are gained if lower removals of BOD, suspen-
ded solids and phosphorus are acceptable. The single stage process will
normally produce reductions in BOD of about 60% with about 80% reductions
in both suspended solids and phosphorus.
The advantages to the use of lime as a flocculant discussed in the
previous sections apply equally well to the single stage processes. In
some instances, however, recalcination may not be cost effective because
of the reduced quantities of lime sludge produced.
A-4 and A-5 ALUM OR FERRIC CHLORIDE ADDITION
The similarities of unit processes A-4 and A-5 are sufficient to warrant
their discussion together. Operationally, these processes are similar to
single stage lime addition. Both the mode of chemical addition and the type
of feed equipment required are essentially the same and the removals of
BODs, suspended solids, and phosphorus are comparable.
The main advantages associated with the addition of either alum or ferric
chloride in comparison to the use of lime lie in the fact that less sludge is
produced, and mineral addition is effective in a pH range which is compati-
ble with biological treatment systems. However, the sludge that is produced
is more dilute and generally more difficult to dewater.
A -11
-------
Both alum and ferric chloride are salts of strong acids and
weak bases. Thus, when they are added to wastewater they form floe
through reaction with the alkalinity present in the waste. If sufficient
alkalinity is not present it must be added by dosing with small amounts
of lime, or soda ash; the former being more frequently used.
Because both coagulants require the same type of equipment and
achieve comparable results, the main factors involved in the selection
of one over the other are the local cost of the materials and the ease
with which either chemical can be handled at the specific plant site.
Since wastewater composition and chemical costs vary considerably
over the United States, the choice between these two must be made on
a case by case basis.
ITEMS INCLUDED IN COST ESTIMATE
Capital Cost
Costs for clarifier sludge removal devices, piping, all pumps and
sludge thickeners were included.
O 8t M Costs
For two stage lime treatment a dose rate of 400 mg/1 (as CaO)
was assumed while for single stage lime treatment 200 mg/1 was used.
Ferric chloride and alum dosages of 80 and 170 mg/1 respectively were
assumed. For all processes, the alkalinity of the wastewater was taken
as 300 mg/1. For the ferric chloride addition, this necessitated a supple-
mentary lime dose of 35 mg/1 (as CaO).
Normal allowances for operation and maintenance of the equipment
were included.
A -12
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B. TRICKLING FILTRATION
A trickling filter consists of a circular bed packed with filter
media, usually rock or a synthetic material. Primary effluent is uni-
formly applied over the media by means of a reaction driven rotary
distributor. Microorganisms grow as a slime layer on the filter me-
dia and consume the organic material in the wastewater oxidizing a
portion to carbon dioxide and water and converting the remainder to
cell mass. Cellular material accumulates on the media until the com-
bined effect of gravity and the flushing action of the percolating wastewater
causes it to slough off. The treated wastewater containing this cellular
material is collected in an underdrain system and conveyed to a second-
ary clarifier where the solids are removed as secondary sludge. A
portion of the filter effluent may be returned as recycle before or after
clarification.
Prior to the development of plastic media, trickling filters were
largely limited to a depth of approximately 6 feet and BOD removals to
about 75%. However with the development of lightweight media.bed depths
greater than 20 feet are common. This reduces the required land area
and increases the process efficiency.
The primary advantage of trickling filters is their simplicity of
operation and dependability. Also, the relatively small amount of sludge
produced is more easily dewatered then activated sludge.
The main disadvantages of trickling filters are their high land
requirements, high capital cost and lower degree of process control. These,
particularly in larger plants, outweigh the advantages noted above.
- 13
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The subalternatives (Bl, B2, B3) for trickling filters relate
to the strength of the feed from different modifications of the primary
treatment and not to changes in the trickling filter process itself.
ITEM INCLUDED IN COST ESTIMATES
Capital Costs
All costs for the filter structure, media, distribution system,
collection system and secondary clarification system are included for
six foot deep rock filters. Costs for raw waste pumping are not in-
cluded since they would be covered, if required, by the raw waste pump-
ing station. However, pumps and piping to provide for a 1:1 recycle ratio
are included. Cost for thickening the secondary sludge by means of gra-
vity thickeners are also included.
O fa M Costs
Operating and maintenance costs include all direct labor and ma-
terial required to operate and maintain the process in a proper manner.
- 14
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C. ACTIVATED SLUDGE
Unlike a trickling filter, which is a fixed growth process
activated sludge- is a. suspended growth process which biologi-
cally breaks down complex organic oxygen-demanding materials.
A well-operated activated sludge system, preceded by primary se-
dimentation, is capable of removing in excess of 90 percent of the
BOD and over 90 percent of the suspended solids in the influent waste-
water.
The activated sludge system consists of aeration basins where
primary effluent is continuously mixed with microorganisms. Air or
oxygen required in the basin is introduced by means of diffusers or
mechanical aerators. This aeration provides necessary dissolved
oxygen to the microorganisms and sufficient mixing to maintain the
cells in suspension. In a subsequent operation the activated sludge
solids are separated from the treated wastewater. A portion of the
microorganisms are returned to the aeration basins to be mixed with
the incoming wastewater while the excess, which constitutes the waste
sludge is sent to the sludge handling facilities.
The degree of treatment achieved in the activated sludge pro-
cess is a function of several parameters. Most important of these are
the mass of microorganisms returned per unit of biodegradable organic
material (BOD) contained in the wastewater and the retention time of the
aeration basins. In the design and operation of activated sludge systems
these variables are combined into a single factor called the organic load-
ing or food to microorganism ratio (F/M). This is defined as the amount
of biodegradable organic material to a given amount of microorganisms
per unit of time.
A -15
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signation Organic
Loading
(F/M)
C1-C3 0.25-1.0
C6 1-3
BOD Suspended solids
Removal Removal
90%
70%
90%
70%
Activated sludge systems are classified as high rate, con-
ventional, or extended aeration (low rate) based on the organic loading.
In domestic waste-water treatment, extended aeration is not as frequently
used because of the high biodegradability of the organic materials present
in sewage. As a result, cost data for this process are not included.
The table shown below gives the BOD and suspended solids removals
which maybe expected for conventional and high rate systems.
P rocess
Conventional
High Rate
Processes Cl through C3 differ only by the type of primary effluent re-
ceived. Two stage lime treatment is not commonly employed prior to
activated sludge treatment because of the high quality of effluent produced
by lime treatment.
High rate activated sludge alone does not produce an effluent with BOD
and suspended solids concentrations suitable for discharge into most surface
waters in the United States. Thus, it is employed generally as a pretreatment
process in a two stage activated sludge system, where the second stage is used
fcr biological nitrification. In such an application it is desirable to carry a
substantial amount of BOD (40-50 mg/l)into the nitrification step to develop
sufficient biological solids in the nitrification reactor to aid in clarification
of the nitrified effluent. Conversely, high rate activated sludge offers
little additional treatment to the high quality effluent from primary treat-
ment with single-stage lime, alum or ferric chloride addition.
A. -16
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Alum or ferric chloride are, however sometimes added directly
to the aeration basins of either the conventional or high rate activated
sludge systems after conventional primary sedimentation to precipitate
phosphorus. This treatment will remove about 80% of the phosphorus.
Cost data for these alternates are included under processes C4, C5, C7
and C8.
The main advantage to both conventional and high rate activated
sludge systems is the lower initial cost of the systems particularly
where a high quality effluent is required. This advantage is sometimes
offset, in smaller plants, by the greater degree of operational complexity
and higher operating costs of activated sludge systems.
ITEMS INCLUDED IN COST ESTIMATES
Capital Costs
Costs were developed using a F/M ratio of 0. 5 for conventional systems
and 1. 5 for high rate systems. The aeration system and all other mechanical
equipment and structures, (basins, buildings, etc. ) were included. Secondary
clarifiers were sized for an average overflow rate of 600 gal/day/ft^ in all
alternates. Provisions for sludges wastage and thickening were included.
For those alternates involving chemical additions the dosage rates were the
same as those specified for addition during primary sedimentation. Facilities
for chemical storage and feed were included.
O & M Costs
Operating and maintenance costs include all direct labor required to
operate and maintain the process in a proper manner. Where appropriate,
all chemical costs were determined on the same bases as in primary treat-
ment.
A. - 17
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D. GRAVITY FILTRATION
All of the suspended matter in wastewater cannot be removed by
gravity settling even after coagulation and flocculation. Thus, if a low
effluent suspended solids concentration is required, filtration of the
biological or two stage lime treatment effluent is generally necessary.
Filtration consists of passing the waste-water through a bed of po-
rous material, separating the suspended matter from the water. As
solids accumulate in the filter bed, it becomes necessary to backwash
the bed by passing clean water at a high rate through the filter in a re-
verse direction to that of normal flow. The wash water, containing the
suspended solids, is generally returned to the head of the plant and re-
cycled through the primary clarifiers, although the wash water optionally
can be returned to the other plant clarifiers when appropriate.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The capital cost of a filter installation is a function of the loading
rate at which the wastewater may be applied. This loading is determined
by characteristics of the filter media and the solids level of the -water being
2
applied. For this study a filtration rate of 4 gal/min/ft was assumed,
which is satisfactory for either a high quality biological effluent or effluent
from two stage lime treatment. Facilities for storage of backwash water
and all requisite pumps and piping were included.
O&M Costs
The O&M costs include all power and labor associated with filtration
and backwash cycles.
A -18
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E. GRANULAR ACTIVATED CARBON
At times it is necessary to achieve a greater degree of BOD removal
than can be obtained by biological or two stage lime treatment combined
with filtration. In such cases, it may be advantageous to use activated carbon
adsorption when the residual BOD is in a soluble form. Treatment by this
method consists of passage of the waste through a series of granular activated
carbon columns. The soluble organics in the wastewater are adsorbed by the
carbon, producing an effluent with less than 5 mg/1 BOD.
With time, the carbon in the first column of the series becomes sa-
turated with organic material. At this time the column is removed from
service and the flow is directed to the next column in the series. The
exhausted carbon is removed and the unit refilled with fresh material,
after which it is placed back in service.
The exhausted carbon is reactivated by burning off organic material
in a specially designed furnace. In each regeneration cycle, there is approx-
imately 5 percent loss of carbon which has to be replenished with purchased
material.
Activated carbon also aids in the removal of bacteria and viruses. Fur-
ther, it reduces the levels of organo-metallic compounds, pesticides and
other materials •which may have not been removed in preceding treatment steps.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major equipment included in estimating the capital cost is listed
below.
1. Carbon columns including carbon beds
2. Regeneration furnace
3. Building
4. Backwash system
A - 19
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O&M Costs
O&M costs are broken down evenly between labor associated
with carbon columns and furnace and material costs. Materials costs,
in turn, are divided evenly between make-up carbon and fuel for the re-
generation furnace.
- 20
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F. TWO-STAGE TERTIARY LIME TREATMENT
This process is very similar in purpose to primary sedimentation.
With two-stage lime addition, however, it follows, rather than precedes,
biological treatment.
Reasons for placing lime treatment after biological treatment in-
clude:
o additional BOD removal
o phosphorous removal
o lime sludge produced is relatively uncontaminated with
organic matter
The reader is directed to the discussion of Primary Sedimentation with
Two-Stage Lime Addition, unit process A2. for a more complete descrip-
tion and other information pertaining to efficiency and cost.
A 21
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G. BIOLOGICAL NITRIFICATION
Nitrogen in the form of ammonia and organic nitrogen compounds
is present in medium strength domestic sewage at a concentration averaging
30 mg/1. High effluent ammonia concentrations are undesirable because
ammonia can be toxic to fish, while both ammonia and organic nitrogen exert
oxygen demand upon the receiving waters. Further since many forms of ni-
trogen including ammonia and organic nitrogen compounds serve as nutrients
for aquatic growth, discharge of these compounds can contribute to eutro-
phication of receiving waters. Thus, in situations where eutrophication is
of concern, complete removal of nitrogen may be required. In other appli-
cations, where oxygen resources of the stream are important, oxidation to
the nitrate form may be adequate.
Conventional biological nitrification is similar to activated sludge
treatment. The difference is that biological nitrification relies on a spe-
cial group of autotrophic bacteria. These microbes derive energy by oxi-
dizing ammonia to nitrite and thence to nitrate. Carbon for synthesis of
cellular material is derived from carbon dioxide. Conventionally, biological
nitrification is preceeded by treatment designed to achieve partial BOD re-
moval. This reduces the size of the nitrification units but allows carry-over
of some BOD to the nitrification reactors to stimulate the growth of hetero-
trophic organisms in the nitrification system which both removes the residual
BOD and facilitates capture of the nitrifying bacteria in the clarifier.
Four different process options for biological nitrification are presented
depending on the nature of the preceeding treatment steps. From a cost
standpoint, the chief difference in these lies in the amount of air required
in the reactor.
Air must be supplied not only for the biological conversion of ammo-
nia to nitrate, but also for the removal of carbonaceous BOD. Therefore,
A -22
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systems with higher influent BOD concentrations will have greater air
requirements. System G2 treats relatively low-BOD effluent from
the trickling filter process and has the lowest air requirement. Pro-
cesses Gl and G4 treat influents with moderate BOD concentrations
and have intermediate air requirements. System G3 has the greatest
air requirement of the four systems.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major pieces of equipment included in the Capital Cost are
listed below:
1. Aeration basins
2. Diffused air system
3. Final clarifiers
4. Return sludge pumps
O&M Costs
Labor costs for plant operation and maintenance of equipment are
the major component of the O&M Costs.
- 23
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H. BIOLOGICAL DENITRIFICATION
If nitrogen removal is desired in addition to oxidation, biological
nitrification will be folio-wed by denitrification. In this process the nitri-
fied effluent is treated anoxically. In an anoxic environment, heterotro-
phic organisms convert the nitrates to nitrogen gas by utilizing nitrate
as an oxidizing agent in the absence of dissolved oxygen. An outside
carbon source, such as methanol, is generally required to provide food
and energy to the denitrifiers.
Following denitrification, wastewater enters an aeration basin where
air is blown into the liquid to release the nitrogen gas and to oxidize the
last traces of methanol. Clarification follows and the denitrifying bac-
teria are returned to the anoxic reactor.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major pieces of equipment considered in the capital cost are
listed below:
1. Anaerobic reactors
2. Aeration basins
3. Diffused air system
4. Return sludge pumps
5. Final clarifiers
6. Methanol storage and feed system
O & M Costs
The greatest single O & M is that for methanol, which is assumed to
be added at a rate of 3. 5 Ibs of rnethanol per Ib of nitrate-nitrogen.
A -24
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I. ION-EXCHANGE
An alternative to biological nitrification is the removal of ammonia
by ion exchange. In this process, the wastewater is passed through a bed
of clinoptilolite, a zeolite resin which selectively removes the ammonium ion.
Once saturated with ammonium ions, the resin is regenerated with a lime
slurry containing sodium chloride.
The waste produced by the regeneration is an alkaline, aqueous ammo-
nia solution •which requires final disposal. In this study, the waste is passed
through a packed tower into which air or steam is injected to strip the ammo-
nia gas. This ammonia gas is passed through an absorber material which has
a high selectivity for ammonia. Disposal of the ammonia-bearing absorber
material is not included.
Process efficiency is comparable to that of the conventional biological
nitrification, with 0. 5 to 1. 0 mg/1 ammonia in the effluent.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major pieces of equipment included in the capital cost are listed
below:
1. Clinoptilolite beds
2. Ammonia absorber
3. Regenerant storage
4. Stripping tower
Major O&tM Costs
Material represents a significant portion of O&M costs. Most notable
are:
1. Makeup clinoptilolite
2. Makeup regenerant
3. Ammonia absorbing material
The disposal of the ammonia-laden absorbing material is not included
here but must be considered in estimating total O&M costs.
-A. 25
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J. BREAKPOINT CHLORINATION
The addition of chlorine to ammonia laden water results in the
production of chloramines. These chloramires may be further oxi-
dized to nitrogen gas and nitrous oxides by adding additional chlorine
to the "break-point". The gases formed are released from, the water to
the atmosphere.
Breakpoint chlorination offers a significant advantage in the re-
moval of ammonia in that capital costs are very low. However, in
larger plants, this is usually more than offset by the high cost of the
chlorine required. Further, depression of the pH by the chlorine may
require the addition of some lime for pH control prior to discharge.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major pieces or equipment included in the capital cost are
listed below.
1. Chlorine storage and feed system
2. Lime storage and feed system
3. Chlorine contact tank
O&M Costs
1. Chlorine
2. Lime
- 26
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K. AMMONIA STRIPPING
Ammonia may be removed from wastewater by a physical stripping
process. If the pH of a wastewater is raised to about 11 esentially all
of the ammonium ion is converted to free ammonia. This gas may then
be stripped by passing the waste through a packed tower having a counter
current flow of air.
Stripping towers can be very effective in ammonia removal but their
efficiency is highly dependent on air temperature. As the air tempera-
ture decreases, the ammonia removal efficiency drops significantly.
This process, therefore, is not recommended in a cold climate. A ma-
jor operational disadvantage of stripping is calcium carbonate scaling
in the tower, which has been a persistent problem. Furthermore, the
discharge of ammonia to the atmosphere can be a significant source of
air pollution.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The major pieces of equipment included in the capital cost are listed
below.
1. Ammonia stripping towers
2. Blower
OfcM Costs
Costs are divided between power and labor.
A - 27
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R. DISINFECTION
Chlorination has been the most widely used method of disinfection of
water and wastewater in the United States for many years. The efficiency
of chlorine in the destruction of bacteria and viruses, combined with its
relatively low cost, as compared with other disinfectants, has dictated
its use in nearly all cases.
Because chlorine readily reacts with many substances found
in wastewater, the effectiveness of chlorine as a disinfectant is depen-
dent on a number of factors including pH, chlorine dosage, contact
time, temperature, ammonia concentration, and the concentrations of
other competing substances.
Since the determination of the bacterial levels in wastewater
requires a minimum of 24 hours by standard techniques, such tests are
of little use in controlling the process of chlorination. Thus, common
practice has been to maintain a chlorine residual after a stipulated contact time
Bactericidal observations of the effects at varying chlorine residuals are
used to establish the required free chlorine residual and then the dosage of
chlorine. Normally, a 15 minute contact time at maximum flow is provided
with the chlorine dosage being automatically varied according to flow and
residual.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
The chlorine storage and feed system plus contact basins are in-
cluded in estimating the capital cost.
O & M Costs
The major component of O & M Costs is chlorine. For this effort,
costs are based on a chlorine dose of 10 mg/1.
- 28
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L. ANAEROBIC DIGESTION
Anaerobic digestion is a common method of sludge treatment used
in domestic waste treatment plants. The process makes use of microor-
ganisms to decompose the complex organic constituents in the sludges to
methane, carbon dioxide and inert solid material. Methane has considerable
fuel value and when removed from the digester may be used to heat buildings,
produce steam, or to drive generators for the production of electricity. In
addition to stabilizing degradable organic material, anaerobic digestion also
results in a substantial decrease in the quantity of solids requiring further
treatment and disposal.
Anaerobic digestion may be performed in either a single digester
tank or in two tanks connected in series. In the latter case, the first tank,
called the primary digester receives the raw sludge. The sludge is heated
and continuously mixed to promote bacterial growth and good food - microor-
ganisms contact. After a period of detention, the sludge is transferred to the
second tank which is maintained in a quiescent state to promote separation
of the solids into as thick a sludge as possible. Periodically, the water (super-
natant) which has separated from the sludge in the secondary digester is de-
canted off and returned to the wastewater treatment operations. The solids
are removed as a stabilized sludge from the bottom of the second stage diges-
ter and are pumped to subsequent sludge treatment operations. Single stage
digestion does not achieve as high a degree of sludge stabilization or gas pro-
duction as the two stage system. Single stage digesters are not as frequently
used in modern plants and therefore, cost figures provided in this study are
based on two stage digestion.
A -29
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Eor the purposes of determing cost effectiveness, two unit pro-
cesses have been presented. These differ only in the nature of the
influent sludge. Process LI treats sludges from conventional sedi-
mentation and biological processes while unit process L2 receives slud-
ges from wastewater processes where chemicals are used to assist se-
dimentation or to remove phosphorus. Because of this difference, unit
process LI will achieve a greater reduction in solids resulting in smaller
dewatering systems.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
Capital costs include tanks, mixers, heating devices, controls and
all other appurtances inherent in the process. Devices for the collect-
ion of gas from the digesters are included but no provision is made for
the of utilization of this gas for power recovery.
O&M Costs
Labor represents the most significant OfeM cost for anaerobic di-
gestion. This process requires a high degree of operating control and
supervision for peak efficiency. Various tests must be run periodically
to monitor the digestion process and make appropriate adjustments.
Proper maintenance requires the cleaning of digesters periodically and
repairing equipment.
The cost of final sludge disposal has not been included here but must
be considered for determination of total O&M costs.
- 30
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M. HEAT TREATMENT
Heat treatment is a sludge dewatering process used as an alter-
native to anaerobic digestion. Raw sludge is heated with steam to appro-
ximately 360 F causing cellular material to rupture and release bound
water, and water of hydration. After cooking at elevated pressure for
about 30 minutes the sludge is cooled and discharged to a settling and
thickening tank. Sludge is withdrawn from the thickener at 8 to 14%
solids and pumped to a dewatering device.
The overflow from the thickener is a high-strength liquor typically
containing 4500 mg/1 BOD. This represents a considerable organic load
if returned directly to the head of the plant. Pretreatment of the clarified
liquor is sometimes practiced to reduce the BOD load to the system.
Heat treatment systems also are divided into two unit processes de-
pending on the nature of the feed sludge. Unit process M-l receives sludge
from conventional sedimentation and biological treatment whereas M-2 is
applicable for those sludges which contain chemical coagulants.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
Cost provisions were made for all necessary mechanical equipment
including heat exchangers, reactors, thickeners and an additional aeration
treatment system for thickener overflow.
O&M Costs
Operation and maintainance costs include all direct labor, steam gene-
ration, and a suitable allowance for replacement parts.
- 31
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N. AIR DRYING
Air drying is a method of further concentrating a sludge after it
has been stabilized by anerobic digestion. This process reduces the
moisture content of the sludge to facilitate handling and transport to
an ultimate disposal site.
The sludge drying beds used in air drying are commonly constructed
of a gravel bed covered by a layer of sand one half to one foot deep. The
size of the beds is determined by the solids content of the influent sludge,
the wetter the sludge the more land needed. The sludge beds can be designed
as covered or open. Covered beds allow an all weather operation and there-
by achieve a more efficient drying, thus a smaller land area is required.
Conversely open beds, require relatively large areas and have a potential
for causing problems that maybe objectionable. Both evaporation, and
seepage of moisture through the bed to an underdrain system are used to
reduce the moisture content of the influent sludge. Natural evaporation is
affected by surface winds, air temperature, and relative humidity. Seep-
age is affected by loading rates, influent sludge characteristics, and the
nature of the filter media. The percolate is collected from the underdrains
and returned to the head of the plant for treatment.
For purposes of this study, cost estimates were based on open beds.
Operation and maintenance costs include bed cleaning but not ultimate dis-
posal.
Air drying is divided into two unit processes , Nl and N2, according to
the nature of the influent sludge. Combined chemical and biological sludge
is treated in process N2, while process Nl treats only biological sludge.
- 32
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ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
Costs are included for sand-gravel open air beds complete with under-
drain system. Provision has also been made for collection of the percolate
in a sump and pumping back to the head of the plant.
O&M Costs
Labor for sludge application, and removal is included. Appropriate
provision has also been made for bed repair.
The cost of final sludge disposal has not been included here but must be
considered in a determination of complete O&M costs.
- 33
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Q. DEWATERING
The purpose of dewatering is to reduce the moisture content of
raw or digested sludge. By increasing the solids content to approximately
30%, the cost of ultimate disposal is greatly reduced through reduction in
both the weight and volume of material handled.
Vacuum filtration is probably the most popular method of mechani-
cal dewatering in use and therefore is the method considered in this
study. Depending on the nature of the sludge involved, dewatering may
be preceeded by conditioning with chemicals, usually lime and ferric
chloride, or organic polyelectrolytes.
The vacuum filter consists of a vat in -which a cylindrical drum
rotates. Sludge is fed to the vat where it forms a pool in the lower portion.
The drum is partially covered by filter medium, which may be a cloth of
natural or synthetic fibers, coil springs, or a wire mesh fabric. As the
drum rotates slowly, part of its circumference is subject to an internal
vacuum that draws sludge to the filter medium and permits the water to
be drawn from the porous filter cake.
The solids are retained on the filter medium for removal as a cake
during the drying cycle. The filtrate, in turn, passes into a compartment
in the interior of the drum, -where it is drawn to the filtrate receiver for return
to the head of the plant.
Unit processes 01, 02, 05 and 06 refer to vacuum filtration of chemically
conditioned sludges. These processes differ only in the character of the sludge
received from the specific process. A filter cake of about 20% solids is nor-
mally achieved.
Unit processes 03, 04 and 07 deal with sludges produced by processes
employing lime. These are separately considered because of the larger quan-
tities of sludge to be handled. These sludges do not ordinairly require chemical
conditioning and maybe dewatered to 25-30% solids. Unit processes 08 and 09
cover dewatering of thermally conditioned sludges. No conditioning chemicals
are required in these cases as well.
A - 34
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ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
Capital cost estimates include all mechanical equipment, pumps.
piping, etc. An allowance is included for a structure to house the fil-
ter and controls. Where applicable, tanks for sludge conditioning are
included.
O&M Costs
Costs include all labor and materials for normal operation and
maintenance. Where applicable chemical costs for lime and ferric
chloride are included at indicated application rates.
- 35
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P. INCINERATION %
Incineration is capable of considerable reduction in both weight
and volume of dewatered sludges. Several types of commercial units
are available; however the most common is the multiple hearth furnace
used in this study. In this furnace,temperatures are maintained at
slightly over 1400 F to insure complete combustion of the organic ma-
terial. The sludge is burned with the aid of auxiliary fuel in the pre-
sence of excess air and after combustion produces an odorless and
inert solid residue and combustion gases. These gases are sent to
the afterburners and air scrubbers before being discharged to the atmos-
phere. The amount of sludge reduction varies directly with the volatile
solids and moisture content of the feed sludge, but average 80 to 94%.
Due to the nature of various unit processes preceeding incineration,
seven cases of incineration were evaluated in this study. Incineration
has not been considered for sludges with low volatile solids contents,
such as the digested sludges, since fuel requirements would be excessive.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
All necessary mechanical equipment, controls and other necessary
equipment are included along with the devices required for air pollution
control and ash handling. An allowance is made for a suitable structure
for housing the incinerators.
OfcM Costs
Maintenance of incinerators including refractory replacement, con-
veyers, ash handling equipment, control center, and enclosing structure
are included. Also included are the costs for electric power, auxiliary fuel
and ash removal. The cost of ash disposal has not been included here but
must be considered in determining total O&M costs.
A - 36
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Q RECALCULATION
Lime recalcination consists of heating lime sludge in a furnace to
temperatures of about 1850 F, driving off water and converting calcium car-
bonate to calcium oxide plus carbon dioxide. The carbon dioxide, and other
stack gases, are passed through an afterburner and air scrubber. Carbon
dioxide may be collected and used in other treatment processes. The re-
calcined lime, is conveyed to a storage hopper and mixed with makeup
lime from a makeup lime storage bin.
Sludge character, and economic considerations determine what frac-
tion of the influent sludge should be reclaimed. For example, the cost of
new lime plus the cost of disposal of the lime sludge must be compared with
the cost of equipment, fuel and operation of the recalcining facilities. With
processes such as two stage lime treatment, the need for CO is also a
factor which should be considered.
Three cases under recalcination are presented. These are based
on the variations in both quality and quantity of the influent lime sludge.
ITEMS INCLUDED IN COST ESTIMATES
Capital Cost
Allowances are included for all mechanical equipment, storage vessels
and instrumentation.
O&M Costs
Estimates for fuel, labor and power are included. The quantity of lime
recovered by recalcination is deducted from the quantity of lime used in the
wastewater treatment processes.
- 37
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APPENDIX B COST EQUATIONS
-------
APPENDIX B
COST EQUATIONS
Three formulae have been developed for each unit process. They are:
1. A formula for amortized capital cost
2. A formula for fixed operation and maintenance costs
3. A formula for flow-variable operation and maintenance cost
The formulae have been developed in such a manner that the following
variables may be changed as time and/or specific conditions warrant:
Variable
Plant capacity
Amortization Period
(5)
Interest Rate
Service and Interest Factor
Labor Rate
Land Cost
Wholesale Price Index
Industrial Commodities' '•
National Average Wastewater
Treatment Plant Cost Index<4)' ^5^~
Symbol
Q
n
i
SIF
MHR
ULC
WPI
STP
Value Used
to Determine
Cost Curves(l)
1, 5, 20, 100
20
5-5/8
27
5
2000
120
177. 5
(1) Refers to "A Guide to the Selection of Cost-Effective Wastewater
Treatment Systems. "
(2) This includes allowance for engineering, contingencies, and interest
during construction.
(3) As of February 1973.
(4) As of February 1973.
(5) For April 1975, WPI = 169. 7 STP =: 232. 5
and i = 5 7/8% (Water Resources Council).
B-l
-------
Two expressions used commonly deserve a brief explanation.
The term 1 appears in each of the three cost formulae and is
3650 Q
used to convert dollars per year into cents per thousand gallons. The
term i (1+i) appears in the formula for total amortized cost. It is
known as the capital recovery factor and converts total capital invest-
ment in dollars to a yearly amortized cost in dollars per year based on
interest rate i and amortization period n.
Several other terms appear commonly throughout each group of formulae.
They are (l)base capital cost, BCC, (2) land requirements, LR, (3)base
manhours, BMH, and (4) base material cost, BMC. Each term varies
with flow for each unit process. Besides appearing individually in each
group of unit process cost formulae, they are summarized in Table III-I
appearing at the end of this section.
Note that the cost formulae have been developed using a least squares
curve fitting method. The equations that appear in this section represent
the best choice of equation over the range of input values. This is impor-
tant to know when using the cost formulae for very small values of Q. In
these situations, some equations yield negative values. This is true, for
instance, with the formula for the land requirement for the ion-exchange
process:
LR = - 0.17 + 0. 021 Q
For values of Q less than 8, the value of LR is less than 0.
The reader should realize that this occurs only due to poor curve fit at low
values of Q. In such occurrences, a zero value should be substituted for
any negative numbers thus obtained. Und»r no circumstances should a ne-
gative value be used.
B - 2
-------
The following formulae apply to any of the unit processes for which
flow sheets were developed in Section II.
Total Amortized Capital Cost, <£ / 1000 Gal. -
ii- -»
CRF(1)
where
BCC, Base Capital Cost, $ . = Refer to Table B-l
LR, Land Requirement, Acres - Refer to Table B-l
Fixed Operation and Maintenance Costs, <£/1000 Gal. =
where
BMH, Base Man-hour Requirement, Man-hours/Yr. = Refer to Table B-l
Variable Operation and Maintenance Costs, £/1000 Gal. =
where
BMC, Base Material Costs, $/Yr. = Refer to Table B-l
(1)
CRF (Capital recovery factor) =i(l+i)n
B-3
-------
Table B-l
FLOW VARIABLE COST ELEMENTS
Unit
Process
AA
AB
Al
A2
A3
A4
A5
Bl
B2
B3
Cl
C2
C3
C4
C5
C6
C7
C8
D
E
Fl
F2
Gl
G2
G3
G4
H
I
Base Capital
Cost (BCC)
3233! Q°'61
163612 Q°'62
139753 + 17341. 2 Q
307785 + 33538.6 Q
198801 + 19934. 9 Q
241226 + 33921.4 Q
269563 + 33561. 5 Q
232882 + 84335 Q
241083 + 63200. 5 Q
241083 + 63200. 5 Q
359744 + 84786.7 Q
349156 + 67047.4 Q
349156 + 67047.4 Q
395978 + 89419.7 Q
411240 + 89839. 2 Q
348852 + 53752. 3 Q
395350 + 59528.6 Q
413737 + 59627.4 Q
231495. OQ°'66
629840 + 90719.4 Q
327175 + 33438.9 Q
327175. 0 + 33438. 9 Q
210055 + 59204.6 Q
203714 + 56924.2 Q
209599 + 65633.4 Q
210055 + 59204.6 Q
155767 + 37290. 7 Q
163270 Q°'88
Land
Requirement(LR)
0
0
0.23 + 0.088 Q
0. 16 + 0. 18 Q
0. 68 + 0. 11 Q
0. 26 + 0. 16 Q
0. 26 + 0. 16 Q
1.20Q0'81
0.79Q0'84
0.79Q0'84
0.76Q0'80
0.46 + 0.32 Q
0.46 + 0. 32 Q
0.78Q0'81
0.78Q0'81
0. 50 Q°- 84
0.78Q0'81
0. 50 Q°- 84
0.024 + 0.028 Q
0. 024 + 0.028 Q
0. 16 + 0. 18 Q
0. 16 + 0. 18 Q
0.50Q0'84
0.50Q0'84
0.44 + 0.24 Q
0.50Q0'84
0.49 + 0. 16 Q
-0. 17 + 0. 021 Q
Base
Manhours (BMH)
1379. 2 + 143. 1 Q
738. 2 + 39.9 Q
1852. 8 Q°'42
0 41
4259.3 Q
3260. 8 + 161. 1 Q
2783. 4 Q°'47
2805. 5 Q°-43
2558.4 Q°'51
2500. 8 Q°-48
2500. 8 Q°'48
4574. 8 Q°'45
6228.4 + 303. 5 Q
6228.4 + 303. 5 Q
0 47
4834. 7 Q
5093. 2 Q°'47
0. 44
4292.9 Q
6959. 8 + 360.6 Q
4898.9 Q°'45
Q
0. 00068 +0.00058 Q
1600. 0 Q
2981. ID0'46
2981. 1Q°-46
3503. 5 + 192.4 Q
3360. 1 + 183. 9 Q
3820.6 + 226. 0 Q
3503. 5 + 192.4 Q
2031. 1Q°'42
3746. 2 Q°'72
Base Materials
Cost (BMC)
860.6 + 247.7 Q
Q
0.000885 + 0.000023 Q
1158.4 Q°-62
2956. 2 Q°'66
1694.4 Q°'65
Q
0. 0000662 + 0. 00000036 Q
2982.5 + 14255.3 Q
4097.3 + 902.0 Q
3525. 8 + 895. 8 Q
3525. 8 + 895. 8 Q
10499.7 Q°'73
10233. 9 Q°'73
10233. 9 Q°'73
184641. 1 + 15301. 8 Q
18720. 2 + 14714.7 Q
10336.4 Q°'73
18466. 2 + 15301. 5 Q
20047.7 + 14697.0 Q
16491. 9 Q°'68
Q
0.00011245 + 0,00000014 Q
2027. 6 Q°'65
2027. 6 Q°'65
8756. 5 Q°'75
8756. 5 Q°'75
8756. 5 Q°'75
8756. 5 Q°-75
-3559.4 + 8110.1 Q
15161. 5 Q°'86
B-4
-------
Table B-l (Continued)
Unit
Process
J
K
R
LI
L2
•Ml
M2
Nl
N2
01
O2
03
04
05
06
O7
08
09
PI
P2
P3
P4
P5
P6
P7
Ql
Q2
Q3
Base Capital
Cost(BCC)
136587 Q°'52
93029.1 Q°'89
62270.5 + 5127. 1 Q
111168 + 23450.4 Q
103721 + 21188.3 Q
92686.9 + 12701.3 Q
101672 Q°'55
-14885.6 + 57978.60
Q
0.00000971 +0.000000101 Q
153201 + 27538. 5 Q
123189 Q°'?1
194601.0 +45218.2 Q
173784 + 37399. 2 Q
140189 + 22599.2 Q
152608 + 22520. 1 Q
168827 + 31955.5 Q
127953 + 13386.5 Q
123931 + 18524.6 Q
0. 54
378837 Q
386161 Q°>5?
631877 + 67043.6 Q
410798 Q°'58
286299 Q°' "
390808 Q°' 54
634606 + 65598.6 Q
422409 Q '
331428 Q°'54
534671 Q°'59
Land
Requirement (LR)
-0.081 + 0.047 Q
-0.016 + 0.04 Q
0.21 + 0.018 Q
0.40 + 0. 09 Q
0.32 +0.09 Q
0
0
1.5 + 1.9 Q
Q
0. 287 + 0.0000972 Q
-0.026 + 0.021 Q
-0. 026 + 0.016 Q
-0.046 + 0.021 Q
-0.043 + 0.018 Q
-0.04 + 0.018 Q
-0.026 + 0.017 Q
-0.043 + 0.016 Q
-0.023 + 0.015 Q
-0.026 + 0.016 Q
-0.084 + 0.015 Q
-0.084 + 0.012 Q
-0.084 + 0.011 Q
0
-0.084 + 0.013 Q
-0. 084 + 0. 015 Q
-0, 084 + 0.012 Q
-0. 17 + 0.021 Q
-0. 17 + 0.021 Q
-0. 17 + 0.021 Q
Base
Manhours (BMH)
3043. 2 Q°'41
3385.6 + 660. 2 Q
462. 6 Q°-6°
923.39 + 108.1 Q
896. 1 + 94. 2 Q
2246.7 + 313.9 Q
2039.8 + 314.7 Q
Q
0.000518 + 0.00001161 Q
Q
0.000490 + 0.000002 Q
2264. 1 + 488.9 Q
2510.8 + 514.9 Q
2624. 6 Q0'78
2391. 8 + 920.04 Q
1899.5 + 385.5 Q
2339.4 + 405.2 Q
3352. 5 + 880.9 Q
1916.3 + 482.0 Q
1966. 1 + 507.7 Q
1280.6 + 509.2 Q
1521.8 + 504.7 Q
1281. 8 + 735.4 Q
1286.8 + 609. 1 Q
1519.3 + 291.4 Q
1433. 9 + 492. 1 Q
1464. 1 + 697. 8 Q
3048.8 + 550.9 Q
1770.4 + 356.9 Q
1904.0 + 911. 1 Q
Base Materials
Cost (BMC)
2399.3 + 39947. 7 Q
2103.0 + 3490.0 Q
-1748.7 + 2739.3 Q
1384.2 + 152.4 Q
1441.8 + 140.7 Q
2810.5 + 1025.8 Q
2148.8 + 1025.0 Q
5.4 + 822.7 Q
Q
0.001156 - 0.0000136 Q
6231. 8 Q°'86
8059. 1 + 3513.6 Q
8681. OQ°-7°
6875. 3 Q°'73
6061.6Q0'86
5978. IQ0'88
7524. 1 Q°'71
4058. 8 Q°'73
4481.9 Q°'71
7136.4 +728.8 Q
9938.7 + 933.7 Q
20391. 1 + 1974. 8 Q
13163.9 + 1214.7 Q
7926.8 + 549.8 Q
12703.3 + 1267.2 Q
8507. 3 + 891. 9 Q
4264. 7 + 14698. 8 Q
3267. 5 + 7913.7 Q
-262.8+ 12458.3 Q
B-5
-------
APPENDIX C COST EFFECTIVENESS
ANALYSIS GUIDELINES
-------
24639
Title 40—Protection of the Environment
CHAPTER I—ENVIRONMENTAL
PROTECTION AGENCY
SUBCHAPTER D—GRANTS
PART 35—STATE AND LOCAL
ASSISTANCE
Appendix A—Cost-Effectiveness Analysis
On July 3, 1973, notice was published
In the PKDERAL REGISTER that the En-
vironmental Protection Agency was pro-
posing guidelines on cost-effectiveness
analysis pursuant to section 212(2) (c) of
the Federal Water Pollution Act Amend-
ments of 1972 (the Act) to be published
as' appendix A to 40 CPR part 35.
Written comments on the proposed
rulemaking were invited and received
from interested parties. The Environ-
mental Protection Agency has carefully
considered all comments received. No
changes were made in the guidelines as
earlier proposed. All written comments
are on file with the agency.
Effective date.—These regulations shall
become effective October 10, 1973.
Dated September 4, 1973.
JOHN QUARLES,
Acting Administrator.
APPENDIX A
COST EFFECTIVENESS ANALYSIS GUIDELINES
a. Purpose.—These guidelines provide a
basic methodology for determining the most
cost-effective waste treatment management
system or the most cost-effective component
part of any waste treatment management
system.
b. Authority.—The guidelines contained
herein are provided pursuant to section 212
(2) (C) of the Federal Water Pollution Con-
trol Act Amendments of 1972 (the Act).
c. Applicability.—These guidelines apply
to the development of plans for and the
selection of component parts of a waste
treatment management system for which a
Federal grant is awarded under 40 CFR,
Part 35.
d. Definitions.—Definitions of terms used
In these guidelines are as follows:
(1) Waste treatment management sys-
tem.—A system used to restore the integrity
of the Nation's waters. Waste treatment
management system Is used synonymously
with "treatment works" as defined In 40
CFR, Part 35.905-15.
(2) Cost-effectiveness analysis.—An analy-
sis performed to determine which waste
treatment management system or compo-
nent part thereof will result in the minimum
total resources costs over time to meet the
Federal, State or local requirements.
(3) Planning period.—The period over
which a waste treatment management sys-
tem is evaluated for cost-effectiveness. The
planning period commences with the Initial
operation of the system.
(4) Service life.—The period of time dur-
ing which a component of a waste treat-
ment management system will be capable of
performing a function.
(5) Useful life.—The period of time dur-
ing which a component of a waste treat-
ment management system will be required to
perform a function which is necessary to
the system's operation.
e. Identification, selection and screening
of alternatives—(1) Identification of alter-
natives.—All feasible alternative waste man-
agement systems shall be Initially Identified.
These alternatives should Include systems
discharging to receiving waters, systems
using land or subsurface disposal techniques,
and systems employing the reuse of waste-
water. In Identifying alternatives, the possi-
bility of staged development of the system
shall be considered.
(2) Screening of alternatives.—The iden-
tified alternatives shall be systematically
screened to define those capable of meeting
the applicable Federal, State, and local
criteria.
(3) Selection of alternatives.—The
screened alternatives shall be Initially ana-
lyzed to determine which systems have cost-
effective potential and which should be fully
evaluated according to the cost-effectiveness
analysis procedures established in these
guidelines.
(4) Extent of effort.—The extent of effort
and the level of sophistication used In the
cost-effectiveness analysis should reflect the
size and importance of the project.
f. Cost-Effective analysis procedures—(1)
Method of Analysis.—The resources costs
shall be evaluated through the use of oppor-
tunity costs. For those resources that can be
expressed in monetary terms, the Interest
(discount) rate established in section (f) (5)
will be used. Monetary costs shall be calcu-
lated in terms of present worth values or
equivalent annual values over the planning
period as defined in section (f) (2). Non-
monetary factors (e.g., social and environ-
mental) shall be accounted for descriptively
in the analysis in order to determine their
significance and impact.
FEDERAL REGISTER, VOL. 38, NO. 174—MONDAY, SEPTEMBER 10, 1973
C-l
-------
24640
The most cost-effective alternative shall be
the waste treatment management system
determined from the analysis to have the
lowest present worth and/or equivalent an-
nual value without overriding adverse non-
monetary costs and to realize at least Identi-
cal minimum benefits In terms of applicable
Federal, State, and local standards for ef-
fluent quality, water quality, water reuse
and/or land and subsurface disposal.
(2) Planning period.—The planning period
for the cost-effectiveness analysis shall be 20
years.
(3) Elements of cost.—The costs to be
considered shall Include the total values of
the resources attributable to the waste treat-
ment management system or to one of Its
component parts. To determine these values,
;vll monies necessary for capital construction
costs and operation and maintenance costs
shall be Identified.
Capital construction costs used In a cost-
effectiveness analysis shall include all con-
tractors' costs of construction including over-
head and profit; coats of land, relocation, and
right-of-way and easement acquisition;
design engineering, field exploration, and en-
gineering services during construction; ad-
ministrative and legal services Including
costs of bond sales; startup costs such as op-
erator training; and interest during con-
struction. Contingency allowances consistent
with the level of complexity and detail of the
cost estimates shall be Included.
Annual costs for operation and mainte-
nance (including routine replacement of
equipment and equipment parts) shall be
Included in the cost-effectiveness analysis.
These costs shall be adequate to ensure ef-
fective and dependable operation during the
planning period for the system. Annual costs
shall be divided between fixed annual costs
and costs which would be dependent on the
annual quantity of wastewater collected and
treated.
(4) Prices.—The various components of
cost shall be calculated on the basis of mar-
ket prices prevailing at the time of the cost-
effectiveness analysis. Inflation of wages and
prices shall not be considered in the analysis.
The Implied assumption is that all prices
Involved will tend to change over time by
approximately the same percentage. Thus,
the results of the cost effectiveness analysis
will not be affected by changes In the gen-
eral level of prices.
Exceptions to the foregoing can be made
If their is Justification for expecting signifi-
cant changes in the relative prices of certain
items during the planning period. If such
cases are identified, the expected change in
these prices should be made to reflect their
future relative deviation from the general
price level.
(5) Interest (discount) rate.—A rate of 7
percent per year will be used for the cost-
effectiveness analysis until the promulgation
of the Water Resources Council's "Proposed
Principles and Standards for Planning Water
and Related Land Resources." After promul-
gation of the above regulation, the rate
established for water resource projects shall
be used for the cost-effectiveness analysis.
(6) Interest during construction.—In cases
where capital expenditures can be expected
to be fairly uniform during the construction
period. Interest during construction may be
calculated as IX Vz P X C where:
I=the interest (discount) rate in Section
1(5).
P = the construction period in years.
C=the total capital expenditures.
In cases when expenditures will not be
uniform, or when the construction period
will be greater than three years, Interest dur-
ing construction shall be calculated on a
year-by-year basis.
(7) Service life.—The service life of treat-
ment works for a cost-effectiveness analysis
shall be as follows:
Land Permanent
Structures 30-50 years
(includes plant buildings,
concrete process tankage,
basins, etc.; sewage collec-
tion and conveyance pipe-
lines; lift station struc-
tures; tunnels; outfalls)
Process equipment 15-30 years
(Includes major process
equipment such as clarlfler
mechanism, vacuum filters,
etc.; steel process tankage
and chemical storage facili-
ties; electrical generating
facilities on standby service
only).
Auxiliary equipment 10-15 years
(includes Instruments and
control facilities; sewage
pumps and electric motors;
mechanical equipment sucb
as compressors, aeration sys-
tems, centrifuges, chlori-
nators, etc.; electrical gen-
erating facilities on regular
service).
Other service life periods will be acceptable
when sufficient Justification can be provided.
Where a system or a component Is for
Interim service and the anticipated useful
life Is less than the service life, the useful
life shall be substituted for the service life of
the facility in the analysis.
(8) Salvage value.—Land for treatment
Works, Including land used as part of the
treatment process or for ultimate disposal of
residues, shall be assumed to have a salvage
value at the end of the planning period equal
to its prevailing market value at the time of
the analysis. Right-of-way easements shall
be considered to have a salvage value not
greater than the prevailing market value at
the time of the analysis.
Structures will be assumed to have a
salvage value If there is a use for such struc-
tures at the end of the planning period. In
this case, salvage value shall be estimated
using straightllne depreciation during the
service life of the treatment works.
For phased additions of process equipment
and auxiliary equipment, salvage value at the
end of the planning period may be estimated
under the same conditions and on the same
basis as described above for structures.
When the anticipated useful life of a facil-
ity is less than 20 years (for analysis of In-
terim facilities), salvage value can be claimed
for equipment where It can be clearly dem-
onstrated that a specific market or reuse
opportunity will exist.
[FR Doc.73-19104 Piled 9-7-73:8:45 am]
C-2
-------
ABBREVIATIONS AND BIBLIOGRAPHY
-------
AB B RE VIATIONS
BCC
BMC
BOD
BTU
BTU/cu. ft.
CaClz
CaO
Ca (OH)
cu. ft.
cf/lb
cfm
cfs
ft
ft2
gal
gpm
hr
i
1
LR
Ib
mg
mg/1
MGD
MGD/AC
MHR
ml
MLSS
n
NaCl
NH3
02
P
pH
ppm
Q
base capital costs, $
base material costs, $/yr
biochemical oxygen demand
British thermal units
British thermal units per cubic foot
Calcium chloride
Calcium oxide
Calcium hydroxide
cubic foot
cubic feet per pound
cubic feet per minute
cubic feet per second
carbon dioxide
chemical oxygen demand
degree Fahrenheit
Ferric Chloride
foot
square foot
gallons
gallons per day
gallons per day per square foot
gallons per hour
gallons per minute
hour
interest rate, %
liters
land requirement, acres
pounds
milligrams
milligrams per liter
million gallons per day
million gallons per day per acre
manhour rate, $/manhour
milliliter
mixed liquor suspended solids
amortization period, years
sodium chloride - common salt
ammonia
ammonia-nitrogen
Oxygen
Phosphorus
sewage pump
hydrogen ion concentration
parts per million (1 ppm equivalent to mg/1)
flow rate, MGD
-------
RAS returned activacted sludge
RS returned sludge
SIF engineering, contingencies, and
interest during construction;
% of construction
SP sludge pump
SS suspended solids
STP national average wastewater
treatment plant cost index
TKN total kjeldahl nitrogen
T-N total nitrogen
ULC unit land cost, $/acre
VP vacuum pump
WPI wholesale price index for industrial commodities
-------
BIBLIOGRAPHY
CODING OF REFERENCES BY MAJOR UTILIZATION
Treatment Process Characterization 1
Process Design Parameters 2
Sludge Generation 3
Treatment Costs 4
Sludge Handling Costs 5
-------
BIBLIOGRAPHY CODE
Gulp, E. L. , Gulp G. L. , Advanced Wastewater Treatment, 1, 2, 3
Van No strand Reinhold Co., New York, 1971.
Fair, G.M., Geyer, J.C., Okun, D.A., Water and Wastewater 1, 2, 3
Engineering, John Wiley & Sons Inc., New York, 1968.
Metcalf and Eddy Inc. , Wastewater Engineering, McGraw Hill, 1, 2, 3
New York, 1972.
Recommended Standards for Sewage Works, Great Lakes - Upper 2
Mississippi River Board of State Sanitary Engineers, 1972 Edition.
Advanced Wastewater Treatment at South Lake Tahoe, U.S. Gov- 1, 2, 3,
ernment Printing Office, Project 17010 ELQ (WRPD 52-01-67). 4, 5
Barnard, James Lang, Eckenfelder, W. Weoley, Jr., Treatment- 2, 3, 4
Cost Relationships for Industrial Waste Treatment, Technical
Report No. 23, Environmental and Water Resources Engineering,
Vanderbilt University, Nashville, Tennessee, 1971.
Process Design Manual for Phosphorous Removal, U.S. Environ- 1, 2, 3
mental Protection Agency Technology Transfer Program, Prepared
by Black and Veatch, Consulting Engineers, October, 1971.
Process Design Manual for Suspended Solids Removal, for the 1, 2, 3
Environmental Protection Agency, Technology Transfer, Prepared
by Burns and Roe Inc., October, 1971.
Process Design Manual for Upgrading Existing Wastewater Treat- 1, 2, 3
ment Plant, for the Environmental Protection Agency Technology
Transfer, prepared by Ray F. Weston, Inc., Environmental Scient-
ists and Engineers, October, 1971.
Process Design Manual for Carbon Adsorption, for the U.S. En- 1, 2
vironmental Protection Agency Technology Transfer, Prepared
by Swindell-Dressier Company, October, 1971.
Sewage Treatment Plant Design, WPCF Manual of Practice No. 8, 1, 2, 3
Water Pollution Control Federation, Washington, D.C., 1959 (Fifth
Printing, 1972)
Cost Estimating Guidelines for Wastewater Treatment Systems, U.S. 4, 5
Department of the Interior, FWQA, Prepared by Bechtel Corporation,
July, 1970.
-------
BIBLIOGRAPHY CODE
Sludge Handling and Disposal, United States Environmental Protection 2, 3
Agency, Technical Transfer Programs, Design Seminar Publication,
Washington, D.C., Seminar held November 13-14, 1972, Anaheim,
California.
Bird, R.S., A Study of Sludge Handling andDisposal, U.S. Department 2, 3, 5
of the Interior, FWPCA, Publication WP-20-4.
Sludge Processing For Combined Physical-Chemical-Biological Sludges, 2, 3, 5
Prepared for California State WRCB, and the U.S. EPA by Central Contra
Costa Sanitary District, Walnut Creek, California, March 1973.
Estimating Costs and Manpower Requirements for Conventional Waste- 4, 5
water Treatment Facilities, Office of Research and Monitoring, U.S.
Environmental Protection Agency, Prepared by Black and Veatch Con-
sulting Engineers, Kansas City, Missouri, October, 1971.
Cost of Wastewater Treatment Processes, Robert A. Taft, Water Re- 4, 5
search Center, U.S. Department of the Interior, FWPCA, Cincinnati,
Ohio, Prepared by Dorr-Oliver Inc. , December, 1968.
Wastewater Ammonia Removal by Ion Exchange , U.S. Environmental 1, 2, 4
Protection Agency, Project 17010 ECZ 02/71, prepared by Battelle-
Northwest, Richland Washington, and South Lake Tahoe Public Utility
District, South Lake Tahoe, California.
Koon, JohnH., Kaufman, Warren J., Optimization of Ammonia Removal 1, 2, 4
by Ion Exchange Using Clinoptilolite, for the Water Quality Office, Envir-
onmental Protection Agency Grant No. 17080 DAR., Sept. 1971, by Sani-
tary Engineering Research Laboratory, College of Engineering and School
of Public Health, University of California, Berkeley.
Disposal of Brines Produced in Renovation of Municipal Wastewater, U.S. 1, 2, 4
Dept. of Int., FWPCA, Washington, D.C. May 1970, Prepared by Burns
and Roe Inc.
Smith, Robert, McMichael, Walter F. , Cost and Performance Estimates 1, 2
for Tertiary Wastewater Treating Processes, Robert A. Taft Water Re-
search Center, U.S. Department of the Interior, FWPCA, Cincinnati, Ohio,
June, 1969.
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