EPA-600/1-77-008
March 1977
Environmental Health  Effects Research  Series
                                               ROTECTJOH



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                 RESEARCH  REPORTING SERIES

Research reports  of the Office of Research and Development, U.S. Environ-
mental Protection Agency, have been grouped into five series.  These five broad
categories were established to facilitate further development and  application
of environmental  technology.   Elimination  of traditional  grouping  was con-
sciously planned  to foster technology transfer  and a  maximum interface in
related fields. The five series are:
    1.    Environmental Health Effects Research
    2.    Environmental Protection Technology
    3.    Ecological Research
    4.    Environmental Monitoring
    5.    Socioeconomic Environmental Studies
This report has been  assigned to  the ENVIRONMENTAL HEALTH EFFECTS
RESEARCH series. This series describes projects  and  studies relating to the
tolerances of man for unhealthful substances or conditions.  This work is gener-
ally assessed from a  medical viewpoint, including physiological  or  psycho-
logical studies.  In addition to  toxicology and other medical specialities, study
areas include biomedical instrumentation and health research techniques uti-
lizing  animals—but always with intended application to human health measures.
 This document is available to the public through the National Technical Informa-
 tion Service, Springfield, Virginia 22161.

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                                          EPA-600/1-77-008
                                          March 1977
THE COST OF REMOVING  CHLOROFORM AND  OTHER TRIHALOMETHANES

             FROM DRINKING WATER SUPPLIES
                         by

                   Robert M. Clark
                   Daniel L. Guttman
                   John L. Crawford
                   John A. Machisko
            Water Supply Research Division
      Municipal Environmental Research Laboratory
      MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
          OFFICE OF  RESEARCH AND DEVELOPMENT
         U.S. ENVIRONMENTAL PROTECTION AGENCY
                CINCINNATI, OHIO  45268
                  LIBRARY
                      J^'';''  "    'L
                      ^ & i.  uJdl/

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                                 DISCLAIMER
     This report has been reviewed by the Municipal Environmental Research
Laboratory, U.  S. Environmental Protection Agency,  and approved for
publication.  Mention of trade names or commercial  products does not
constitute endorsement or recommendation for use.
                                    ii

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                                  FOREWORD
     The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people.  Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.

     Research and development is that necessary first step in problem solu-
tion and it involves defining the problem, measuring its impact, and searching
for improved technology and systems for the prevention, treatment, and manage-
ment of wastewater and solid and hazardous waste pollutant discharges from
municipal and community sources, for the preservation and treatment of public
drinking water supplies, and to minimize the adverse economic, social, health,
and aesthetic effects of pollution.  This publication is one of the products
of that research; a most vital communications link between the researcher and
the user community.

     Trihalomethanes in general, and chloroform - a known carcinogen - in
particular, are found in drinking water as a direct consequence of the practice
of chlorination, a long established public health practice for the disinfection
of drinking water.  EPA would like to minimize the drinking water consumer's
exposure to trihalomethanes at reasonable cost.  This report is devoted to
the presentation of the results from a research study which examines the
costs of the various treatment technologies suited to the removal and control
of trihalomethanes in drinking water.
                                Francis T.  Mayo
                                Director
                                Municipal Environmental Research Laboratory
                                      111

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                                    PREFACE
     The Safe Drinking Water Act of 1974 has intensified the public awareness
and interest in the quality of drinking water as delivered to the consumer's
tap.  The Act establishes a set of enforceable, health-related regulations
and a set of non-enforceable esthetics-related guidelines for drinking water.
For each health-related standard the Act establishes an associated Maximum
Contaminant Level (MCL) that must not be exceeded.  The Act also contains
provisions for the EPA Administrator to take various courses of action when
a contaminant is detected for which no MCLs have been established.  Trihalo-
methanes in general, and chloroform, recently determined to be a carcinogen
in drinking water, in particular, are examples of such contaminants.

     Trihalomethanes are found in drinking water as a direct consequence of
the practice of chlorination, a long established public health practice for
the disinfection of drinking water supplies.  Recent research has demon-
strated that the concentration of chloroform and related compounds is
generally higher in finished than in raw water, leading to the conclusion
that they are being produced during the chlorination process.

     Acting on these findings, Russell Train, Administrator of the U. S.
Environmental Protection Agency, directed that EPA work with cities and
states to evaluate certain modifications to current treatment practices that
can reduce the formation of chloroform during the water treatment process,
without lessening the effectiveness of disinfection.  Part of this effort
has been the preparation of a document, entitled "Interim Treatment Guide
for the Control of Chloroform and Other Trihalomethanes in Drinking Water."
The "Guide" has been prepared in an attempt to present EPA's knowledge con-
cerning the removal and control of chloroform and other trihalomethanes in
drinking water.  It covers such items as:  changing the point of chlorine
application to reduce chloroform concentrations; the use of alternative
disinfectants, such as ozone or chlorine dioxide; and the use of granular
activated carbon as a medium for the adsorption of organic compounds.

     Appendix I of the "Guide" presents cost information with respect to the
use of granular activated carbon, ozonation, aeration, and chlorine dioxide
for trihalomethane removal.  This report was originally Appendix I of the
"Interim Treatment Guide for the Control of Chloroform and Other Trihalo-
methanes," and provides an in-depth examination of the costs related to the
above-mentioned techniques.
                                      iv

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                                  ABSTRACT
     This research effort was conducted to provide an in-depth examination
of the costs associated with the use of activated carbon, ozonation, aeration,
and chlorine dioxide for removal of trihalomethanes.

     The costs presented in this report are intended for the development of
planning estimates only and not for the preparation of bid documents or
detailed cost estimates.  Exact capital and operating costs are highly vari-
able from location to location within the United States, even for plants of
the same size and design.  These costs are presented in such a way as to
enable the planner to make adjustments to the reported costs when local
information is available.  Standardized levels for a selected set of design
parameters are assumed and sensitivity analysis is performed for the majority
of the parameters.

     Because chlorine is associated with the formation of trihalomethanes,
several technological alternatives which may be used in lieu of or in
combination with chlorination are examined.  Costs are presented for the
chlorination process itself.  Costs are also calculated for ozonation,
chlorine dioxide, aeration, and granular activated carbon.  An in-depth
analysis of the costs associated with granular activated carbon systems is
presented.  This analysis includes costs both with and without separate
contactor systems and an examination of the possible cost savings associated
with regional regeneration.

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                              CONTENTS

FOREWORD	   iii
PREFACE	    iv
ABSTRACT 	     v
FIGURES	viii
TABLES	   xii
METRIC CONVERSION TABLE  	   xiv
ACKNOWLEDGMENTS	   xv
     INTRODUCTION  	     1
     COST DETERMINATION  	     2
          Basis of Cost Estimates	     3
     COST OF CHLORINATION	     4
     COST OF CHLORINE DIOXIDE  	     8
     COST OF OZONATION	    19
          Cost of Ozone from Air	    19
          Cost of Ozone from Oxygen	    26
     COST OF AERATION	   26
     COST OF GRANULAR ACTIVATED CARBON  	   26
          The Cost of GAG as Filter Media Replacement	   48
          Additive Modifications 	  69
          Multiplicative Modifications 	  74
          Regional Reactivation 	   74
          Separate Contactor System 	   80
          Capital Investment 	  90
          Labor Costs for GAG Systems	   90
     SUMMARY AND CONCLUSIONS 	  92
REFERENCES	95
                                 Vll

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                                   FIGURES


Number                                                                 Page

   1     Total Unit Cost for Chlorination Versus Plant Size 	    6

   2     Capital and 0 & M Costs for Chlorination Versus Plant Size .    7

   3     0 & M Cost for Chlorination Systems Versus Cost of Chlorine     9

   4     0 & M Cost for Chlorination Systems Versus Direct Hourly
           Wage Rate	10

   5     0 & M Cost for Chlorination Systems Versus Wholesale Price
           Index	11

   6     Amortized Capital Cost for Chlorination Systems Versus
           Chlorine Contact Time	12

   7     Amortized Capital Cost for Chlorination Systems Versus
           Interest Rate	13

   8     Amortized Capital Cost for Chlorination Systems Versus
           Construction Cost Index 	  14

   9     Amortized Capital Cost for Chlorination Systems Versus
           Amortization Period 	  15

  10     0 & M Cost for Chlorination Systems Versus Chlorine Dosage.  .  16

  11     Amortized Capital Cost for Chlorination Systems Versus
           Chlorine Dosage 	  17

  12     Total Unit Cost for Chlorine Dioxide Versus Plant Size  ...  21

  13     0 & M Cost for Chlorine Dioxide System Versus Plant Size   .  .  22

  14     Total Unit Cost for Ozonation (Air) Versus Plant Size ....  24

  15     Amortized Capital and 0 & M Costs for Ozonation  (Air)
           Versus Plant Size	25
                                    Vlll

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                                 FIGURES (Cont.)

Figure                                                                  Page

  16      0 & M Cost for Ozonation (Air) Versus Direct Hourly
          Wage Rate	27

  17      0 & M Cost for Ozonation (Air) Versus Wholesale Price
          Index	28

  18      0 & M Cost for Ozonation (Air) Versus Electric Power Cost .   .  29

  19      Amortized Capital Cost for Ozonation (Air) Versus Ozone
            Contact Time	   30

  20      Amortized Capital Cost for Ozonation (Air) Versus Construc-
            tion Cost Index	   31

  21      Amortized Capital Cost for Ozonation (Air) Versus Interest
            Rate	   32

  22      Amortized Capital Cost for Ozonation (Air) Versus
            Amortization Period 	  33

  23      0 & M Cost for Ozonation (Air) Versus Ozone Dose	   34

  24      Amortized Capital Cost for Ozonation (Air) Versus Ozone
            Dose	   35

  25      Total Unit Cost of Ozonation (Oxygen) Versus Plant Size  .  .   37

  26      Amortized Capital and 0 & M Costs for Ozonation (Oxygen)
            Versus Plant Size	38

  27      0 & M Cost for Ozonation (Oxygen) Versus Liquid Oxygen Cost  .  39

  28      Amortized Capital Cost for Ozonation (Oxygen) Versus
            Liquid Oxygen Cost	   40

  29      Construction Cost for an Aeration Basin Versus
            Volume of Basin	43

  30      Annual 0 & M Costs for Air Supply Versus Standard Cubic Feet
            per Minute Throughput	44

  31      Construction Cost for Air Supply Versus Standard
            Cubic Feet per Minute Throughput	   45
                                     IX

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                                   FIGURES (Cont.)

Figure                                                                  Page

  32     Total Unit Cost Versus Plant Size	    50

  33     Amortized Capital and 0 & M Costs Versus Plant Size 	    51

  34     Total Unit Cost for a 100 mgd Plant Versus Time Between
           Reactivations in Months 	    52

  35     Total Unit Cost for a 100 mgd Plant Versus the Product
           of Time Between Reactivations in Months and Capacity Factor    53

  36     0 & M Costs Versus Direct Hourly Wage Rate	55

  37     0 & M Cost Versus Carbon Loss per Reactivation Cycle 	  56

  38     0 & M Cost Versus Fuel Cost	    57

  39     0 & M Cost Versus Wholesale Price Index	    58

  40     0 & M Cost Versus Electrical Power Cost	    59

  41     Amortized Capital Cost Versus Construction Cost Index ....    60

  42     Amortized Capital Cost Versus Amortization Interest Rate  .  .    61

  43     Amortized Capital Cost Versus Amortization Period 	    62

  44     0 & M Cost Versus Carbon Cost	    63

  45     Amortized Capital Cost Versus Carbon Cost 	    64

  46     0 & M Cost Versus Reactivation Frequency	    65

  47     Amortized Capital Cost Versus Reactivation Frequency  ....    66

  48     0 & M Cost Versus Interaction Between Reactivation Frequency
           and Capacity Factor	    67

  49     Amortized Capital Cost Versus Interaction Between Reactivation
           Frequency and Capacity Factor  	    68

  50     Percent Change in Plant Cost Versus Carbon Loss 	    70

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                                  FIGURES (Cont.)

Number                                                                  Page

  51     Total Unit Costs Versus Plant Size	75

  52     Construction Cost for Carbon Reactivation System Versus
           Reactivation Rate	   78

  53     0 & M Cost for Carbon Reactivation System Versus
           Reactivation Rate	79

  54     Cost of Transporting Carbon from a 1 mgd Plant to Regional
           Reactivation Site Versus Distance in Miles  	 83

  55     Cost of Transporting Carbon from a 5 mgd Plant to Regional
           Reactivation Site Versus Distance in Miles 	  84

  56     Cost of Transporting Carbon from a 10 mgd Plant to Regional
           Reactivation Site Versus Distance in Miles 	  85

  57     The Sensitivity of Reactivation Costs to Transportation
           Cost Variations	   86

  58     Comparison of Costs Between Contactor System and Media
           Replacement Versus Plant Capacity 	   88
                                     XI

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                                  TABLES
Number                                                                 Page

   1    Design Parameters for the Cost of Chlorination 	   5

   2    Chlorine Cost Assuming Standardized Design Levels  	  18

   3    Chlorine Dioxide Costs Assuming Standardized Design Levels .  .  20

   4    Design Parameters for Ozonation 	   23

   5    Ozone (Air) Costs Assuming Standardized Design Levels ....   36

   6    Ozone (Oxygen) Costs Assuming Standardized Design Levels  .   .   41

   7    Design Parameters for Aeration 	  42

   8    Aeration Costs Assuming Standardized Design Levels 	  46

   9    Design Parameters for Granular Activated Carbon  	   49

  10    Design Parameters Affecting 0 & M Costs (100 mgd)	   71

  11    Design Parameters Affecting Capital Costs (100 mgd)  	   72

  12    New Effect for Design Parameters at High and Low Levels
          (100 mgd)	   73

  13    Carbon Costs and Reactivation for Regional Reactivation Systems 77

  14    Amortized Capital and Operating Costs for Off-Site
          Reactivation Systems 	  81

  15    Reactivation Systems Cost for an Individual Plant  	  82

  16    Assumptions for Separate Contactor Systems  	  87

  17    Amortized Capital and 0 & M Costs for Contactor  Versus Filter
          Media Replacement - 0/1000 gal	89
                                     Xll

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                                  TABLES (Cont.)
Number                                                                 Page

  19    Estimated Construction Cost of Granular Activated Carbon
          Reactivation Furnaces 	   90

  18    Investment Costs for Granular Activated Carbon Treatment:
          Replacement of Media and Separate Contactors (Thousands
          of Dollars)	   91

  20    Labor Costs for 1, 10, and 100 mgd GAG Systems Reactivating
          On-Site (Filter Shell Replacement)  	   93

  21    Comparison Among Systems (c/1000 gal) 	   94
                                   xixi

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                   METRIC CONVERSION TABLE
English Units




1 foot




1 mile




1 square mile




1 million gallons




1 $/million gallons




1 c/1000 gallons
Metric Equivalents




0.305 meters




1.61 kilometers




2.59 square kilometers




3.79 thousand cubic meters




0.26 $/thousand cubic meters




0.26 C/cubic meter
                                xiv

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                        ACKNOWLEDGMENTS
The authors gratefully acknowledge the assistance of the
following individuals in the preparation of this report:
Mr. Gordon G. Robeck, Dr. James M. Symons, Dr. 0. Thomas Love,
and Mr. J. Keith Carswell of the Water Supply Research Division,
and Mr. Richard Eilers of the Wastewater Research Division.
                              xv

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           THE COST OF REMOVING CHLOROFORM AND OTHER TRIHALOMETHANES
                         FROM DRINKING WATER SUPPLIES

                                      BY

                          *                   +                  +
           Robert M. Clark , Daniel L. Guttman ,  John L. Crawford ,

                            and John A. Machisko
INTRODUCTION

     The Safe Drinking Water Act of 1974 will change the way water is
handled before it is distributed to the consumer.10  The Act contains two
types of provisions for drinking water as delivered to the consumer's tap:
a set of enforceable regulations that are health-related, and a set of
non-enforceable guidelines that are related to the esthetics of drinking
water.  Each health-related standard has an associated Maximum Contaminant
Level (MCL) that must not be exceeded.  The Act also contains provisions
for the Administrator, U. S. Environmental Protection Agency (EPA) to take
various courses of action when a contaminant is detected for which no MCLs
have been established.1  Trihalomethanes in general and chloroform in partic-
ular, recently determined to be a carcinogen in drinking water, are examples
of such contaminants.

     Trihalomethanes are found in drinking water as a direct consequence of
the practice of chlorination, a long established public health practice for
the disinfection of drinking water.  It is probable that chlorine has been
reacting with certain organic materials to produce chloroform and related
organic byproducts since chlorination was initiated.  These compounds in drink-
ing water escaped detection due to their low concentrations and because of
their low boiling points, which allowed them to be lost during procedures used
for performing typical organic analyses in water. ^
   Systems Analyst, Water Supply Research Division, Municipal Environmental
     Research Laboratory, U. S. Environmental Protection Agency, Cincinnati,
     Ohio  45268.

   Research Assistants, Water Supply Research Division, Municipal Environ-
     mental Research Laboratory, U. S. Environmental Protection Agency,
     Cincinnati, Ohio  45268

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     Recently, investigators have developed new, more sensitive analytical
procedures which allow for more precise measurement of trihalomethanes.  The
newly developed procedures have been used to demonstrate that the concentra-
tion of chloroform and related compounds is generally higher in finished than
in raw water, leading to the conclusion that they are being produced during
the chlorination process.

     Acting on these findings, Russell Train, Administration of the U. S.
Environmental Protection Agency, on March 29, 1976, released a statement that
said in part, "... The recent test results and the fact that chloroform is
prevalent in the environment have convinced me that the prudent course of
action at this time is to minimize exposure to this chemical wherever it is
feasible to do so."  He also said, "EPA will work with cities and states to
evaluate certain modifications to current treatment practices that can reduce
the formation of chloroform during the water treatment process, without
lessening the effectiveness of disinfection.  EPA research has shown that
changes in chlorination procedures practiced by some water systems can result
in reduction in the levels of chloroform produced.  EPA plans to share these
initial findings on chloroform reduction with the states and some cities
encountering high chloroform levels, in an effort to reduce human exposure as
quickly as possible.  This will also allow EPA to gain added information to
support the development of national regulations to limit chloroform levels in
water supplies."

     An interim guide, entitled "Interim Treatment Guide for the Control of
Chloroform and Other Trihalomethanes in Drinking Water," has been prepared
in an attempt to present EPA's knowledge concerning the removal and control
of chloroform and trihalomethanes in drinking water.  The "Guide" covers such
iLems as:  changing the point of chlorine application to reduce chloroform
concentrations; the use of alternative disinfectants, such as ozone or
chlorine dioxide; and the use of granular activated carbon as a medium for
the adsorption of organic compounds.

     The "Guide" summarizes EPA's current knowledge and recent research
results related to the removal and control of chloroform and other trihalo-
methanes.  It also presents cost information with respect to the use of
granular activated carbon, ozonation, aeration, and chlorine dioxide for
trihalomethane removal.  This report has been developed as a support document
for the "Guide" and provides an in-depth examination of the costs related to
the above-mentioned techniques.1^

COST DETERMINATION

     The costs presented in this report are intended for the development of
planning estimates only and not for the preparation of bid documents or
detailed cost estimates.  Exact capital and operating costs are highly
variable from location to location within the United States, even for plants
of the same size and design.  Variables — such as local costs of land,
materials, and labor; state or regional differences in building codes; and
existing facilities suitable for modification — may accentuate the
differences in treatment costs for similar plants to reduce chloroform and
other trihalomethanes in drinking water.

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     These cost data are presented in such a way as to enable the planner to
make adjustments to the reported costs when local information is available.
For example, operation and maintenance costs can be reduced if the delivered
cost of chemicals is less than the costs upon which the estimates are based.
Costs indices are used to provide a baseline for projecting costs and for
estimating escalation due to inflation.  The indices used in this report are
national indices, but other indices are often available for major U. S.
cities or on a regional basis and may be substituted if desired.

Basis of Cost Estimates

     The cost indices used in this report are:

     a.   EPA's Sewer and Sewage Treatment Plant Construction Cost Index:
          This index was used because most of the basic information utilized
          in the report was obtained from the Systems and Economic Evaluation
          Section of EPA's Wastewater Research Division.9>3  por example,
          computations for granular activated carbon were performed using
          a computer program developed by the Systems and Economic Evalua-
          tion Section, but operational modifications were assumed in the
          analysis to reflect conditions unique to water supply.H  The
          index should reflect similar costs for water treatment plant con-
          struction and for January 1976 is 256.7.
                                2
     b.   Wholesale Price Index:   The Wholesale Price Index (WPI) is the
          oldest continuous statistical series published by the Bureau of
          Labor Statistics (BLS).  It is a measure of the price changes for
          goods sold in primary markets in the United States.  "Wholesale,"
          as used in the title of the index, refers to sales in large quanti-
          ties, not prices received by wholesalers, jobbers, or distributors,
          and for January 1976 is 175.1.

     c.   Bureau of Labor Statistics Labor Cost Index (Direct Hourly Wage
          Rate):5  The index used in this report is, for personnel in
          Standard Industrial Category (SIC), 494.7 for Water, Steam and
          Sanitary Systems Non-Supervisory Workers.  The base BLS Labor Cost
          Index for February 1976 is 5.19.

     Costs reported as Capital Costs include:

     a.   construction for site preparation,

     b.   plant construction,

     c.   legal, fiscal, and administrative services,

     d.   interest during construction, and

     e.   start-up costs.

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     Costs reported as Operating and Maintenance Costs include:

     a.    chemical costs,

     b.    labor costs, and

     c.    operation and maintenance costs, such as utilities, annual replace-
          ment of expendable items, etc.

     Because the formation of trihalomethanes is associated with chlorination,
several options will be considered in lieu of chlorination, all more expensive
than the basic chlorination process itself.  The benefits as well as the
problems associated with changing to some alternative must be weighed when
choosing another form of disinfection.  For example, ozonation, while not
creating chloroform, also does not provide any kind of residual disinfectant
in the distribution system.  Moreover, it is conceivable that the byproducts
resulting from disinfecting with chlorine dioxide or ozone might be more harm-
ful than chloroform itself.  Granular activated carbon (GAC) is not a direct
alternative to chlorination, but provides a means of removing organics from
water supplies.  The cost of the processes to be considered - chlorine dioxide,
ozonation, and granular activated carbon - must be weighed against the basic
cost of chlorine disinfection.  Initially, the costs associated with chlori-
nation will be presented.  Next, the directly competitive disinfection
alternatives of chlorine dioxide and ozonation will be discussed.  The cost
of aeration as a means of removing chloroform and other trihalomethanes once
they have been formed and, finally, a cost analysis for granular activated
carbon as a general means of removing organics will be presented.

COST OF CHLORINATION

     Chlorine was first used as a disinfectant for municipal water supplies
in the United States in 1908 to disinfect continuously the water supply of
Jersey City, New Jersey.^  In many water supplies, chlorination is often
the only treatment process used.  When other treatment methods are used,
disinfecting chlorine may be added to the raw water (prechlorination), the
partially treated water, or the finished water (postchlorination).  Where the
distribution system contains open reservoirs, the treated water may be re-
chlorinated in the distribution system.

     In this analysis, a number of variables have been evaluated as to their
effect on the cost of chlorination.  Baseline or standardized design values
for a set of design parameters were assumed and the cost of chlorination,
including chlorine feeding equipment and contact chambers for 1, 5, 10, 100,
and 150 million gallons per day (mgd) systems, was calculated.  The para-
meters and their associated "standardized" levels are shown in Table 1.

     Figure 1 shows the effect of economies of scale, by displaying the total
amortized unit cost of a chlorination system in c/1000 gal versus plant
capacity, based on the values in Table 1.  It can be seen that cost varies
from 3.6C/1000 gal at 1 mgd to 0.6C/1000 gal at 150 mgd.  Figure 2 separates
the total unit costs shown in Figure 1 into unit Amortized Capital and 0 & M
costs.

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 TABLE 1.  DESIGN PARAMETERS FOR THE COST OF CHLORINATION
Design Parameter (Variable)




Chlorine Dose




Chlorine Contact Time




Cost of Chlorine




Construction Cost Index




Wholesale Price Index




Direct Hourly Wage Rate




Amortization Interest Rate




Amortization Period




Electric Power Cost
Level




2 mg/1




20 min




300 $/ton




256.7




178.1




5.19 $/hr




7 percent




20 yr




$0.01/KWH
Design Parameter (Fixed)




Capacity Factor
70 percent

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  6-
O 4-

O
o
O
o
o
t 2^
O  1-
    1510  20     40     60     80     100    120    140    160    180    200

                           PLANT SIZE (MGD)


    FIGURE 1.  UNIT COST FOR CHLORIIMATION VERSUS PLANT SIZE

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                                          AMORTIZED CAPITAL COST
'1 510 20
40
       60
80    100    120
 PLANT SIZE (MGD)
140
160
180
                   200
 FIGURE 2.  CAPITAL AND O&M COSTS FOR CHLORINATION VERSUS PLANT SIZE

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     Figures 3 through 11 show the sensitivity of the cost of chlorination
to variations in all of the design variables listed in Table 1, with the
exception of capacity factor.   Capacity factor has been fixed at 70 percent
to reflect the fact that water treatment systems generally operate at less
than design capacity.  Costs presented in this report, therefore, reflect the
average costs to be expected over a year's operating period.  The sensitivity
analysis assumes that one parameter is varied while the others are fixed at
the standardized levels, and is an attempt to show how costs might vary due
to local conditions.

     The parameters which affect only 0 & M cost are shown in Figures 3, 4,
and 5 as follows:  cost of chlorine, direct hourly wage rate, and wholesale
price index.  It can be seen that all of the parameters have a significant
impact on 0 & M cost.  For example, for a 100 mgd plant, increasing the
cost of chlorine from 300 $/ton to 400 $/ton increases the 0 & M cost from
0.36C/1000 gal to 0.46C/1000 gal (28 percent).  For a 1 mgd plant, increasing
the Direct Hourly Wage Rate from 5.19 $/hr to 6 $/hr raises the 0 & M cost
from 1.40C/1000 gal to 1.56C/LOOO gal (11 percent).

     The parameters which affect Amortized Capital costs are as follows:
chlorine contact time, interest rate, construction cost index, and amortiza-
tion period.  The effects of these variables are shown in Figures 6, 7, 8,
and 9.

     The parameter  (aside from the load factor) which affects both Amortized
Capital and 0 & M costs is chlorine dosage and is shown in Figures 10 and 11.
It can be seen that an increase of 1 mg/1 dosage of chlorine increases the
0 & M cost alone by 0.15C/1000 gal for a 100 mgd plant.  Table 2 summarizes
the cost of chlorination for 1, 5, 10, 100, and 150 mgd systems in C/1000 gal
assuming the levels of the design variables as shown in Table 1.

     As can be seen from the previous analysis, chlorination costs are
relatively stable.  Another form of disinfection is chlorine dioxide dis-
infection which will be discussed in the following section.

COST OF CHLORINE DIOXIDE

     An alternative to chlorine is chlorine dioxide, which does not produce
measurable quantities of trihalomethane, however, there is a possibility of
toxic organic byproducts resulting from the reaction of chlorine dioxide
with organic matter in water.1  In this cost analysis, it was assumed that
half the dosage of  chlorine dioxide as compared to chlorine is required to
achieve equivalent  disinfection results.  Therefore, it was assumed that
1 mg/1 of chlorine  dioxide would achieve disinfection results equivalent to
those achieved by 2 mg/1 of chlorination.  If 0.5 mg/1 of chlorine is combined
with 1.6 mg/1 of technical grade sodium chlorite, a 1 mg/1 dosage of chlorine
dioxide will result.  The equation below shows this relationship  (assuming
80 percent pure NaCIO,., yields 1.3 mg/1 of reactive material):

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o
o
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-------
            23456
               DIRECT HOURLY WAGE RATE ($/HR)
10
FIGURE 4. O&M COST FOR CHLORINATIOIM SYSTEMS VERSUS DIRECT HOURLY WAGE RATE
                                  10

-------
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5
     5 MOD
                                                         150 MOD
               10            20            30

                     CHLORINE CONTACT TIME (MINUTES)
40
             50
   FIGURE 6.  AMORTIZED CAPITAL COST FOR CHLORINATION SYSTEMS VERSUS CHLORINE

            CONTACT TIME
                                  12

-------
                                                          MOD
            56789
                        INTEREST RATES (%)

FIGURE 7. AMORTIZED CAPITAL COST FOR CHLORINATION SYSTEMS VERSUS INTEREST RATE
                                 13

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                                                           150 MGD
   2.0
                2.2
   2.4           2.6

CONSTRUCTION COST INDEX (100)
                                                       2.8
                                                                    3.0
    FIGURE 8.  AMORTIZED CAPITAL COST FOR CHLORINATIOIM SYSTEMS VERSUS

             CONSTRUCTION COST  INDEX
                                  14

-------
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                                                            1 MGD
                                                          150 MGD
   0            10            15           20           25           30

                        AMORTIZATION PERIOD (YEARS @ 7% INTEREST RATE)




    FIGURE 9.  AMORTIZED CAPITAL COST FOR CHLORINATIOIM SYSTEMS VERSUS


             AMORTIZATION PERIOD
                                   15

-------
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   FIGURE 10. O&M COST FOR CHLORIIMATIOIM SYSTEMS VERSUS CHLORINE DOSAGE
                                 16

-------
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                             2             3
                         CHLORINE DOSAGE (MG/L)
    FIGURE 11. AMORTIZED CAPITAL COSTS FOR CHLORIIMATIOIM SYSTEMS VERSUS
              CHLORINE DOSAGE
                                  17

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          2 NaClO?  +  Cl   —>  2 C10?  +  2 Nad
                                                                   (1)
            (181)     (71)        (135)      (117)

          1.3 mg/1   0.5 mg/1    0.9 mg/1   0.8 mg/1

Therefore, the chlorine feeding system and contact basins were estimated for
a 0.5 mg/1 dosage of chlorine with the rest of the standardized values fixed
at the levels shown in Table 1.  The cost of sodium chlorite was estimated
as follows:

     NaC102 cost (c/1000 gal) = ($0.70/lb)(13.34 Ib/mil gal)

                              = 0.934C/1000 gal

     The NaC10» cost was added to the cost of chlorine (0.5 mg/1) to yield the
cost of a 1 mg/1 dosage of C10?.  These values are shown in Table 3 for 1, 5,
10, 100, and 150 mgd plants.   Figure 12 shows the cost of chlorine dioxide
versus treatment plant capacity.    All of the factors which influence the
cost of C10? disinfection with the exception of NaC102 cost, would be the
same as those shown in the section on chlorination.

     Figure 13 illustrates sensitivity in 0 & M cost due to changes in the
cost of NaC102-  Amortized Capital cost sensitivity would be estimated by
examining the effect of changing the Cl_ dosage.

     As can be seen, chlorine dioxide is more expensive than chlorination but
has one advantage in that it can be generated with relative ease in a system
with an existing chlorine feeding system.  The only additional cost for such
an operation would be to the incremental cost for sodium chlorite, although
there are other mechanisms for generating chlorine dioxide, such as by the
use of sodium chlorate, a process commonly used in the pulp and paper industry.
None of these alternative methods are considered here because all of these
systems have been built on a scale much too large for municipal water supply
usage.

COST OF OZONATION

     Another disinfectant which will be considered is ozone, although ozona-
tion does not produce a disinfectant residual to be carried throughout the
distribution system.  Further, the reaction of ozone with organic matter
occurring in water is not known.  For purposes of this analysis, the design
parameters listed in Table 4 have been assumed as standardized and a sensi-
tivity evaluation of the cost of ozonation based on these parameters has been
made for 1, 5, 10, 100, and 150 mgd plants operating at 70 percent capacity.
As ozone can be produced from both air and oxygen, both systems are evaluated.

Cost of Ozone from Air

     Figure 14 depicts the total unit cost for ozone generated by air versus
plant capacity.  The total unit costs are separated into 0 & M and Amortized
Capital costs in Figure 15.  The impact of the variables which affect 0 & M

                                      19

-------
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   '1510  20     40     60     80     100    120


                              PLANT SIZE (MGD)
140
       160
             180
200
    FIGURE 12.  TOTAL UNIT COST FOR CHLORINE DIOXIDE VERSUS PLANT SIZE
                                  21

-------
3.5
3.0
         .1
                      .3      .4      .5      6      .7
                       SODIUM CHLORITE COST (S/LB)
.8
       .9
   FIGURE 13.  O&M COST FOR CHLORINE DIOXIDE SYSTEM VERSUS COST OF
             SODIUM CHLORITE
1.0
                                 22

-------
        TABLE 4.  DESIGN PARAMETERS FOR OZONATION
Design Parameters (Variable)




Ozone Dose




Ozone Contact Time




Cost of Oxygen




Construction Cost Index




Wholesale Price Index




Direct Hourly Wage Rate




Amortization Interest Rate




Amortization Period




Electric Power Cost







Design Parameter (Fixed)




Capacity Factor
Level




1 mg/1




20 min




0.046 $/lb




256.7




178.1




5.19 $/hr




7 percent




20 yr




$0.01/KWH
70 percent
                                23

-------
J-\ 5 10
                                100
                           PLANT SIZE (MGD)
                                                 150
 FIGURE 14.  TOTAL UNIT COSTS FOR OZONATION (AIR) VERSUS PLANT SIZE
                               24

-------
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o
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                                                     CAPITAL COST
                                                       O&M COST
  01 510
      100

PLANT SIZE (MGD)
150
    FIGURE 15.  AMORTIZED CAPITAL AND O&M COSTS FOR OZONATIOIM (AIR)

              VERSUS PLANT SIZE
                                  25

-------
cost are shown in Figures 16 through 18.  These variables are as follows:
direct hourly wage rate, wholesale price index, and cost of electric power in
kilowatt hours.

     Figures 19 through 22 illustrate the sensitivity of capital costs to
the following variables:  ozone contact time, construction cost index, and
interest rate and amortization period.  Ozone dose, as can be seen from
Figures 23 and 24, affects both Amortized Capital and 0 & M costs.

     Table 5 summarizes the costs for 1, 5, 10, 100, and 150 mgd plants based
on standardized levels of the design variables in Table 4.

Cost of Ozone from Oxygen

     Ozone can also be generated by using oxygen.  Figures 25 and 26 show
the total unit costs and the disaggregated costs (0 & M and Amortized Capital),
respectively, versus plant capacity.  Figures 27 and 28 illustrate the sensi-
tivity of the cost of ozonation (0 & M and Amortized Capital costs) to the
cost of liquid oxygen.

     Table 6 summarizes the costs of 1, 5, 10, 100, and 150 mgd plants using
the standardized variables in Table 4.

COST OF AERATION

     Aeration is frequently practiced for the removal of hydrogen sulfide and
reduced materials, such as ferrous iron and manganous manganese.  In the
laboratory, aeration or purging is used as an analytic procedure to remove
trihalomethanes from water and it might therefore be used successfully as a
treatment technique.  Experimentation has shown, however, that at typical
air-to-water ratios used in water treatment for removal of taste- and odor-
causing compounds (1:1) little removal of chloroform takes place.  For this
analysis it was therefore assumed that the air-to-water ratio of 30 cu ft
of air to 1 cu ft of water would provide adequate removal of trihalomethanes,
which is consistent with laboratory results for effective chloroform removal.
Table 7 contains the standardized variables which were examined in the cost
analysis.

     Figure 29 is a typical capital cost curve for an aeration basis as a
function of throughput in thousands of cubic feet.  Figures 30 and 31 are
0 & M Amortized Capital cost curves, respectively, for the diffused aeration
system based on thousands of standard cubic feet per minute of air.  Table 8
contains the cost per thousand gallons for a 1, 5, 10, 100, and 150 mgd
plant based on the standardized cost assumptions shown in Table 7.

COST OF GRANULAR ACTIVATED CARBON

     Granular activated carbon (GAC) is not a substitute for chlorine
disinfection, but is well suited for the removal of various types of dissolved
organic materials including chloroform and other trihalomethanes.  Most but
not all dissolved organics can be adsorbed, which actually removes them  from
solution.    Fresh, granular carbon has the following advantages for water

                                      26

-------
                  34567
                   DIRECT HOURLY WAGE RATE (S/HR)
10
FIGURE 16.  O&M COSTS FOR OZONATION (AIR) VERSUS DIRECT HOURLY WAGE RATE
                                27

-------
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                                                            100 MGD
                                                             OU MUU
         .4
                       1.2     1.6    2.0    2.4     2.8

                           WHOLESALE PRICE INDEX (100)
3.2
3.6
              4.0
    FIGURE 17.  O&M COST FOR OZONATION (AIR) VERSUS WHOLESALE PRICE INDEX
                                   28

-------
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                                               1  MGD
                                             100MGD
                                             =^^^^^
                                             150 MGD
         .005    .010    .015   .020    .025    .030    .035
                     COST OF ELECTRIC POWER ($/KWH)
.040
.045
.050
    FIGURE 18. O&IW COST FOR OZONATION (AIR) VERSUS ELECTRIC POWER COST
                                   29

-------
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                                                           WOO
                                                           MOD
                                                        150
                                                           MOD
               10            20           30

                      OZONE CONTACT TIME (MINUTES)
40
50
   FIGURE 19.  AMORTIZED CAPITAL COSTS FOR OZONATION (AIR) VERSUS OZONE
             CONTACT TIME
                                 30

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                2.2
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                          CONSTRUCTION COST INDEX (100)
                                                                      3.0
   FIGURE 20.  AMORTIZED CAPITAL COST FOR OZOIMATION (AIR) VERSUS CONSTRUCTION

              COST INDEX
                                    31

-------
  3.5
  3.0
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-------
                         20           25
                    AMORTIZATION PERIOD (YEARS)

FIGURE 22. AMORTIZED CAPITAL COST FOR OZONATION (AIR) VERSUS AMORTIZATION PERIOD
                                  33

-------
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                                                    1 MGD
   	5  MGD


                                                   10  MGD
                                                  100 MGD
                                                   150 MGD
                                  1.0

                           OZONE DOSE (MG/L)
   FIGURE 23.  O&M COST FOR OZONATION (AIR) VERSUS OZONE DOSE
                                 34

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                                                    5  MOD
150 MOD
  .5
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                            OZONE DOSE (MG/L)
                 1.5
   FIGURE 24. AMORTIZED CAPITAL COST FOR OZOIMATIOW (AIR) VERSUS  OZONE DOSE
                                    35

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-------
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FIGURE 25.  TOTAL UNIT COST OF OZONATION (OXYGEN) VERSUS PLANT SIZE
                             37

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              (OXYGEN) VERSUS PLANT SIZE
                               38

-------

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                                               5MGD

                                              10 MOD
                    34567
                      LIQUID OXYGEN COST (C/LB)
                                                              10
   FIGURE 27. O&M COST FOR OZONATION (OXYGEN) VERSUS LIQUID OXYGEN COST
                                  39

-------
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   01      23456789     10
                       LIQUID OXYGEN COST (C/LB)


   FIGURE 28. AMORTIZED CAPITAL COST FOR OZOIMATION (OXYGEN) VERSUS

              LIQUID OXYGEN COST
                                40

-------
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-------
        TABLE 7.  DESIGN PARAMETERS FOR AERATION
Design Parameters (Variable)




Air to Water Ratio




Contact Time




Construction Cost Index




Wholesale Price Index




Direct Hourly Wage Rate




Amortization Interest Rate




Amortization Period




Electric Power Cost
        Level




30 cu ft:  1 cu ft




        20 min




        256.7




        178.1




        5.19 $/hr




        7  percent




        20 yr




        $0.01/KWH
Design Parameter (Fixed)




Capacity Factor
        70 percent
                                42

-------
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                                                     1000
    FIGURE 29.  CONSTRUCTION COST FOR AN AERATION BASIN

               VERSUS VOLUME OF BASIN
                           43

-------
   10'
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   10'
   10
                      10               100

               STANDARD CUBIC FEET PER WIN (x 1000)
                                                     1000
    FIGURE 30. ANNUAL O&M COSTS FOR AIR SUPPLY VERSUS

               STANDARD CUBIC FEET PER MINUTE THROUGHPUT
                            44

-------
CO
cc
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     FIGURE 31  CONSTRUCTION COST FOR AIR SUPPLY VERSUS

               STANDARD CUBIC FEET PER MINUTE THROUGHPUT
                            45

-------
46

-------
treatment:

     a.   Adsorption of trihalomethanes that have been formed by chlorina-
          tion practiced prior to GAG treatment;

     b.   Adsorption of most trihalomethane precursors so that chlorination
          can be practiced after treatment with GAG without forming signifi-
          cant quantities of trihalomethanes;

     c.   Reduction of possibility of producing hitherto unknown organic
          byproducts during disinfection by reducing the amount of organic
          matter available for reaction with any disinfectant; and

     d.   Reduction in the general level of organics, thereby increasing
          the likelihood of removal of raw water organic contaminants that
          may be of concern now or in the future.

     Treating water with activated carbon involves two major and separate
process operations:  filtration and reactivation.  The water comes in contact
with the carbon by passing through a structure filled wither with carbon
granules or with a carbon slurry.  Impurities are removed from the water by
adsorption when sufficient time is provided for this process.  The structure
can be either a water treatment filter shell, in which the filter media has
been replaced with GAG or an independent carbon filtration system.  The
separate carbon filtration system usually consists of a number of columns
or basins used as contactors that are connected to a reactivation system.
The primary focus of this economic analysis will be on the use of GAG as a
replacement for existing media in the filter shell.  The economics of a
separate contactor system will also be examined.

     After a period of use, the carbon's adsorptive capacity is exhausted and
it must then be taken out of service and reactivated by combustion of the
organic adsorbate.  Fresh carbon is routinely added to the system to replace
that lost during hydraulic transport and reactivation.  These losses include
both attrition due to physical deterioration and burning during the reacti-
vation process.

     The approach taken in this analysis is first to evaluate the use of GAG
with an on-site reactivation system assuming that the GAG will replace the
media in the filter shell.  Various levels of key design parameters will be
established at standard levels with the intent of evaluating their effect on
sensitivity of the cost of GAG systems.  The "standard" system will consist
as in the previous analysis of fixing a given set of design variables at
predetermined levels.  Secondly, an analysis will be made for the replacement
of GAG in the filter shell but with off-site or regional reactivation.
Finally, an evaluation will be made of the cost of a separate GAG contactor
system with on-site reactivation.
                                     47

-------
The Cost of GAG as Filter Media Replacement

     As mentioned previously, it was assumed that GAG would replace sand in
existing filters, thereby eliminating the need to consider the cost of
separate GAC contactors.  For purposes of this analysis, a water treatment
plant is assumed to consist of an integral number of 1 mgd filters.  For
example, a 10 mgd water treatment system is assumed to consist of ten 1 mgd
filters each with the following dimensions:  18.5' x 18.5' x 2.5', yielding
a total volume of 865 cu ft per filter.

     The standard values and the design parameters chosen for examination
are shown in Table 9. All analyses perform will be based on the effect of
changing the design variables around these standard values.

     Before examining sensitivities, the impact of three basic factors must
be considered:  economies of scale, load factor, and reactivation frequency.
Figure 32 depicts the economies of scale associated with plant size for GAC
systems of 1, 5, 10, 100, and 150 mgd capacity, assuming the design variables
are held at the levels shown in Table 9.  The unit cost for a 1 mgd plant is
approximately 440/1000 gal while the unit cost of a 150 mgd plant is close
to 5.5C/1000 gal.  The cost curve rises sharply between 10 and 5 mgd, jumping
from 120/1000 gal to 15.5C/1000 gal.  Figure 33 shows 0 & M and Amortized
Capital costs versus plant capacity.

     Figure 34 depicts the cost for a 100 mgd plant, operating at a 70 per-
cent capacity factor, with the period between reactivation varying between
0.5 and 18 months.  At might be expected, lengthening the time between
reactivation reduces the unit cost from 7.50/1000 gal at 0.5 months to
1.60/1000 gal at 18 months.

     Figure 35 shows the interaction between capacity factor and reactiva-
tion frequency for a 100 mgd plant, in which it is assumed that the product
of reactivation period and load factor is 1, and that as capacity factor
decreases, the period between reactivations increases.  For example, when
capacity factor is 100 percent, the reactivation frequency is assumed to be
one month, and when the capacity factor is 50 percent the reactivation
frequency is assumed to be two months.  It can be seen that increasing the
time between reactivation periods reduces unit costs; however, this reduced
cost is offset by a reduced load factor which increases the unit cost.  The
net effect is an increased cost from 5.30/1000 gal (100 percent load factor
@ one reactivation per month) to 6.20/1000 gal (50 percent load factor @
one reactivation every two months).

     Having established the impact of these three variables (load factor,
reactivation frequency, and economies of scale), it is possible to examine
the sensitivity of cost to changes in the design parameters in Table 9.
Some of these variables influence only Operating and Maintenance cost, some
only Amortized Capital cost, and some of these variables affect both 0 & M
and Amortized Capital cost.  The first group of variables to be examined that
influence 0 & M cost are as follows:  hourly wage rate  ($/hr), carbon loss
                                      48

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     TABLE 9.  DESIGN PARAMETERS FOR GRANULAR ACTIVATED CARBON
Design Parameters (Variable)

Carbon Cost

Carbon Loss per Reactivation Cycle

Fuel Cost

Electrical Power Cost

Construction Cost Index

Wholesale Price Index

Direct Hourly Wage Rate

Amortization Rate

Amortization Period
Level

0.38c/lb

10 percent

1.26 $/mil BTU

O.Olc/KWH

256.7

178.1

5.19 $/hr

7 percent

20 yr
Design Parameters (Fixed)

Contact Time

Hydraulic Loading Rate

Volume per Filter (1 mgd)

Capacity Factor

Reactivation Frequency

Loss in Adsorptive Capacity
During Reactivation
4.5 min

2 gal/min/sq ft

865 cu ft

70 percent

1.4 months


0
                                  49

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  70,
  60-
O

o
o
°40-
030-
O
z
13
  20-
   01 510  20
40     60     80    100    120

              PLANT SIZE (MGD)
140
       160
              180
200
    FIGURE 32.  TOTAL UNIT COST VERSUS PLANT SIZE
                                    50

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  35
< 30
O
  25
W
O
00
o

Q

I 15
Q
LU
N




I5
   01 510  20    40     60     80    1OO     120

                              PLANT SIZE (MGD)
140
       160
             180
200
    FIGURE 33. AMORTIZED CAPITAL AND O&M COSTS VERSUS PLANT SIZE
                                   51

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o
§
CO
O  3^
O
3
-J
2
                 4     6      8     10     12     14
                 CARBON REACTIVATION FREQUENCY (MONTHS)
                                                     16
18
                                                                  20
    FIGURE 34. TOTAL UNIT COST FOR A 100 MGD PLANT VERSUS TIME BETWEEN
              REACTIVATIONS IN MONTHS
                                   52

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o
o
o
(A
O
o
  1.0     1.2    1.4     1.6     1.8    2.0
  100%         70%                 50%*

  •CARBON REACTIVATION FREQUENCY (MONTHS)
                                       2.2
                                             2.4
2.6
2.8
                                                                3.0"
                                       •CAPACITY FACTOR (%)

FIGURE 35. TOTAL UNIT COST FOR A 100 MGD PLANT VERSUS THE PRODUCT OF TIME

          BETWEEN REACTIVATIONS IN MONTHS AND CAPACITY FACTOR
                                    53

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per reactivation cycle, fuel cost, wholesale price index, and electrical
power cost.  Figures 36 through 40 illustrate the impact which these variables
have on cost.

     Figure 36 shows that changes in hourly wage rate have a greater impact
on the cost of small plants than on large plants.  For example, it can be
seen that as the hourly rate increased from 5.19 $/hr to 7 $/hr, the 0 & M
cost for 1 mgd plant increases from slightly over 21C/1000 gal to slightly
less than 28c/1000 gal.  The same wage rate increase in a 150 mgd plant
increases the 0 & M cost from approximately 4C/1000 gal to 4.50/1000 gal.

     Figure 37 shows the changes in 0 & M costs which result from increases
or decreases in carbon loss per reactivation cycle.  Figures 37 through 40
show that 0 & M cost is very sensitive to changes in carbon loss but is
somewhat less sensitive to changes in fuel cost, wholesale price index, and
electric power cost.

     The group of variables; that influence Amortized Capital cost are as
follows:  Construction Cost Index (CCI), amortization interest rate, and
amortization period in years.  Figure 41 illustrates the variable impact
that CCI has on Amortized Capital cost in C/1000 gal.  The impact is great
for small plants, but decreases for larger plants.  Figure 42 illustrates
the effects of increasing or decreasing interest rate on Amortized Capital
cost.  As with CCI, the effect of changing this parameter is greater for
smaller plants than for larger plants.  Figure 43 shows the same effect for
changes in amortization period.

     Several of the design parameters listed in Table 9 influence both
Amortized Capital and 0 & M cost.  These parameters are as follows:
activated carbon cost, carbon reactivation frequency, and the interaction
of carbon reactivation frequency and load factor.  Figures 44 and 45 illus-
trate the influence that the cost of activated carbon will have on both
Amortized Capital and 0 & M cost.  Figures 46, 47, 48, and 49 show these
same impacts for carbon reactivation frequency and for the interaction of
carbon reactivation frequency and load factor.

     To illustrate how the sensitivity analysis can be applied to the
standard values in order to study the impact of local conditions on costs,
the following example has been constructed.  If it were assumed that all of
the standardized values were held at the levels shown in Table 9, with the
exception of activated carbon loss, it would be possible to estimate the
impact that changes in its value would have on the system cost.  Examining
Figure 37, it can be seen that as compared to the standardized values when
activated carbon loss is 15 percent for a 100 mgd plant the percent change
in 0 & M cost is + 29.5 percent, but when it is at 5 percent, the change is
- 14.7 percent.  The standardized values yield an Amortized Capital cost of
1.5C/1000 gal and an 0 & M cost of 4.5C/1000 gal.  Therefore, as carbon loss
affects only 0 & M cost, the change in total cost would be as follows:

     GAG system cost (15 percent) = 1.5 + [4.5  +  4.5 (.295)]       (2)

                                  = 7.3C/1000 gal                    (3)

                                     54

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  35
  30
< 25
0

O
O
O

5 20
(A
O
O

5
oO
O
15
  10
                                                150 MOD
                       34567

                       DIRECT HOURLY WAGE RATE ($/HR)
                                                                   10
    FIGURE 36.  O&M COST VERSUS DIRECT HOURLY WAGE RATE
                                  55

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  35
  30
  25
020
o
o
o
2.15
o
(J

5 10
o9
O
                                        1MGD
MOD
                                        ! 50 MOD
          .02     .04     .06    .08     .10    .12     .14     .16

                     CARBON LOSS PER REACTIVATION CYCLE (%)
                       .18
.20
    FIGURE 37. O&M COST VERSUS CARBON LOSS PER REACTIVATION  CYCLE
                                    56

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  35
  30
  25



                                           1 MGD
                                       -•-
< 20
O

O
O
O
V)
O
O

5
<*
10
                                        5 MGD
                                        10 MGD
                                         100 MGD
                                         150 MGD
          •02     .04    .06     .08     .10     .12     .14     .16     .18     .20

                           FUEL COST ($/100,000 BTU)


    FIGURE 38. O&M COST VERSUS FUEL COST
                                    57

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  35
  30
  25
o
o
o
o .
t-
V)
O 15
0

5
«0
O
  10
                        I  I  I
| 5 MGD

 10 MGD
                                    100 MGD
                                     150 MGD
          .5     1.0     1.5     2.0     2.5     3.0    3:5
                             WHOLESALE PRICE INDEX (1000)


    FIGURE 39.  O&M COST VERSUS WHOLESALE PRICE INDEX
                       4.0
4.5
5.0
                                      58

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  35
  30
  25


                                         1 MGD
o
o
o
  15
O
O

5
08
O
10
  5-
                                     =t=
 5 MGD

10MGD
                                       100 MGD
                                       150 MGD
   0     .005    .010    .015    .020   .025   .030   .035    .040   .045   .050
                  ELECTRICAL POWER COST (S/KWH)


   FIGURE 40.  O&M COST VERSUS ELECTRICAL POWER COST
                                    59

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            1.0     1.5     2.0     2.5    3.0    3.5     4.0    4.5
         SEWAGE TREATMENT PLANT CONSTRUCTION COST INDEX (1000)

FIGURE 41. AMORTIZED CAPITAL COST VERSUS CONSTRUCTION COST INDEX
5.0
                               60

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  35
  30
O

025

o
  20
O
til
N 10
                                                   5 MOD
          .01     .02     .03     .04    .05    .06    .07

                   AMORTIZATION INTEREST RATE (FRACTION)
.08
       .09
              .10
    FIGURE 42.  AMORTIZED CAPITAL COST VERSUS AMORTIZATION INTEREST RATE
                                     61

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  35
  30
O
o
§25
o
_l
<



o
Q
UJ
N
1C
O
  10
                                        MGD
                 10     15     20     25     30     35

                          AMORTIZATION PERIOD (YEARS)
40
       45
             50
    FIGURE 43. AMORTIZED CAPITAL COST VERSUS AMORTIZATION PERIOD
                                   62

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  35
  30
  25
o
o
o
  15
V)
o
O 10
08

O
   0       .1     .2      .3      .4     .5     .6

                             CARBON COST (S/LB)



    FIGURE 44. O&M COST VERSUS CARBON COST
.8
.9
             1.0
                                   63

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  35
  30
O

O
O
O
£20
O
O
t 15
O.
O

Q
U!
N

I-
DC
O
  10
                                                      1 MOD
                               .4     .5     .6

                            CARBON COST ($/LB)
                                                         .8
                                                                .9
                                                                      1.0
    FIGURE 45.  AMORTIZED CAPITAL COST VERSUS CARBON COST
                                    64

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  35i
  30
  25
O

O 20
o
o
H 15
(/>
O
o


510
o
                                      MGD

                                  150 MGD
    0     .5     1.0    1.5     2.0     2.5    3.0     3.5    4.0

                    CARBON REACTIVATION FREQUENCY (MONTHS)



    FIGURE 46.  O&M COST VERSUS REACTIVATION FREQUENCY
4.5
5.0
                                   65

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  35
-30

<
O
o
o
O 25
(A
820
                           1.MGD.
<

a.

o
o
HI
N


O
2
<
  15
  10
                           5.MGD
                 1.0    1.5     2.0    2.5    3.0    3.5

                  CARBON REACTIVATION FREQUENCY (MONTHS)
                                                        4.0
4.5
                                                                     5.0
    FIGURE 47.  AMORTIZED CAPITAL COST VERSUS REACTIVATION  FREQUENCY
                                  66

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  35
  30
  25
O

O 20
O
O
H 15
tf)
O
U

310
O
   5
5 MOD
                                      100 MGD
                                      150 MGD
                                           2.2
          2.4
                                                        2.6
 1.0    1.2     1.4    1.6     1.8    2.0
100%          70%                50%

CARBON REACTIVATION FREQUENCY (MONTHS) CAPACITY FACTOR (%)
                       2.8
3.0
    FIGURE 48.  O&M COST VERSUS INTERACTION BETWEEN REACTIVATION FREQUENCY
              AND CAPACITY FACTOR
                                   67

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35,
                                       10 MGD
                                       • i     —

                                       100 MGD
                                             -
                                       150 MGD
  1.0    1.2     1.4    1.6     1.8     2.0
 100%          70%                 50%
 CARBON REACTIVATION FREQUENCY (MONTHS) CAPACITY FACTOR (%)

  FIGURE 49.  AMORTIZED CAPITAL COST VERSUS INTERACTION BETWEEN
             REACTIVATION FREQUENCY  AND CAPACITY FACTOR
                                 68

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     GAG system cost (5 percent) = 1.5  +  [4.5  -  4.5  (.147)]      (4)

                                 = 5.3C/1000 gal                      (5)

     Figure 50 illustrates the percent change in cost for 1, 5, 10, 100, and
150 mgd systems that results from various activated carbon losses.

     In the above equations, Amortized Capital cost remains constant as
activated carbon loss affects only 0 & M cost.  Some of the parameters, such
as amortization period, have a multiplicative effect, as will be illustrated
below.  Assuming that amortization period, which affects only Amortized
Capital cost, is in one case 10 years (150.9 percent) and in another case
30 years (85.4 percent), yields the following when compared with the
standardized value of l.Sc/1000 gal:

     GAG system cost (10 years)  =  (1.5)(1.509)  +  4.5              (6)

                                 =  7.5C/1000 gal                     (7)

     GAG system cost (30 years)  =  (1.5)(0.854)  +  4.5              (8)

                                 =  5.8C/1000 gal                     (9)

     Equations 6 through 9 illustrate how the multiplicative factor affects
Amortized Capital cost.

     Table 10 contains the percentage change in 0 & M cost that results from
setting the level for each design parameter at 50 percent, and at 150 percent
(for a 100 mgd plant), of standard values.  Table 11 contains the same
information for Amortized Capital cost (for a 100 mgd plant).  It should be
noted that some of the parameters, such as carbon cost, affect both Amortized
Capital and 0 & M cost.

     The net effect of setting the design value for each parameter at the
high and low values is shown in Table 12.  Using the values shown in Table 12
the 0 & M and Amortized Capital costs are calculated as shown below for a
100 mgd plant.
Additive Modifications                    High

Amortized Capital Cost (c/1000 gal):  1.5 + 1.5 (0.664)

          Sum                               2.5

0 & M (C/1000 gal):                   4.5 + 4.5 (0.675)

          Sum                               7.5
      Low
1.5 - 1.5 (0.730)
      0.4
4.5 - 4.5 (.576)
      1.91
Using the above values the total cost can be calculated as follows:
                                      69

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  +30.0-
  +20.0.
O

0 +10.0-
a.

z  o.oo-

lil
u
z
u

5?
   -10.0'
  -20.0'
   -30.0-
   -40.
       0       2       4       6      8      10     12      14     16      18     20

                                   % CARBON LOSS



       FIGURE 50.  PERCENT CHANGE IN PLANT COST VERSUS CARBON LOSS
                                      70

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   TABLE 10.  DESIGN PARAMETERS AFFECTING 0 & M COSTS (100 mgd)
Parameters Affecting 0 & M Costs - Additive
Carbon Loss per Reactivation Cycle (percent)


Carbon Cost (c/lb)


Fuel Cost ($/mil BTU)


Power Cost (c/KWH)


Direct Hourly Wage Rate ($/hr)


Wholesale Price Index


Values
15
10
5
54
38
19
1.89
1.26
0.63
1.5
1.0
1.5
7.78
5.19
2.60
267
178
89
Percent (
29.6
0
14.7
16.9
0
-22.0
4.0
0
-3.8
0.6
0
-0.6
15.9
0
-15.9
6.0
0
-5.0
Parameters Affecting 0 & M Costs - Multiplicative

Reactivation Frequency (weeks between)           3           145.9
                                                 6           100.0
                                                 9            72.1

Capacity Factor (percent)                       50           105.2
                                                70           100.0
                                               100            92.4
                                   71

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TABLE 11.  DESIGN PARAMETERS AFFECTING AMORTIZED CAPITAL COSTS (100 mgd)
Parameters Affecting Amortized
Capital Cost - Additive

Carbon Cost (c/lb)
 Values       Percent Change

 54               16.9
 38                0
 19              -22.0
Construction Cost Index
385
257
125
 49.5
  0
-51.0
Parameters Affecting Amortized
Capital Cost - Multiplicative

Amortization Period (yr)
Interest Rate (percent)
Reactivation Frequency (weeks between)
Capacity Factor (percent)
10
20
30
10.5
7
3.5
3
6
9
50
70
100
150.9
100.0
85.4
127.3
100.0
73.0
121.5
100.0
91.5
128.9
100.0
76.4
                                   72

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TABLE 12.  NET EFFECT FOR SETTING DESIGN PARAMETERS AT HIGH AND LOW
                          LEVELS (100 mgd)
Additive Factors for 0 & M

Loss per Reactivation
Carbon Cost
Fuel Cost
Power Cost
Hourly Wage Rate
Wholesale Price Index
High (percent)   Low (percent)
    29.5
    16.9
     4.0
     0.6
    15.9
     0.6
-14.7
-22.0
- 3.8
- 0.6
-15.9
- 0.6
                Sum
   +67.5
-57.6
Additive Factors for
Amortized Capital Cost

Carbon Cost
Construction Cost Index
    16.9
    49.5
-22.0
-51.0
                Sum
   +66.4
-73.0
Multiplicative Factors for 0 & M

Reactivation Frequency
Hydraulic Load
     1.459
     1.052
  0.721
  0.924
                Product

Multiplicative Factors for
Amortized Capital Cost

Amortization Period
Interest Rate
Reactivation Frequency
Hydraulic Load Factor
     1.535
  0.666
     1.509
     1.273
     1.215
     1.289
  0.854
  0.730
  0.915
  0.764
                Product
     3.008
  0.436
                                  73

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Multiplicative Modifications         High                 Low

Amortized Capital (c/1000 gal)    (2.5)(3.008)        (0.4)(0.436)

          Product                     7.5                 0.17

0 & M (c/1000 gal)                (7.5)(1.535)        (1.91)(0.666)

          Product                    11.5                 1.27
                    Sum              19C/1000 gal         1.440/1000 gal

Adding the final results for Amortized Capital and 0 & M costs yields a
high value of 19C/1000 gal and a low value of 1.44C/1000 gal.  These results
illustrate the extremes which might result from localized conditions.

     As can be seen from Figures 32 and 33, unit costs associated with
small treatment systems are extremely high.  The bulk of the Amortized
Capital costs are for on-site reactivation facilities, which suggests the
possibility that for small plants some alternative to on-site reactivation
should be explored.  One possibility would be to dispose of exhausted
activated carbon and to purchase new carbon.  The cost of disposal for a
plant operating at 70 percent: capacity factor, with a period between reactiva-
tion of 1.4 months, is shown below:

              (865 cu ft)(No. of filters)(30 lb)(8.57 reactivations)(38c/lb)
Disposal cost =	cu ft	y_r	
                    (flow in mgd)(365 days/yr)(0.70)

Disposal cost =   33-lc/lOOO gal

The above value can be compared to on-site reactivation costs for a 1, 5, 10,
100, and 150 mgd plant operating at 0.7 load factor with once-per-1.4 months
reactivation (Figure 32).  It can be seen from Figure 51 that disposing of
exhausted carbon is actually cheaper than on-site reactivation for small
plants (2 mgd or less) although it is obviously more expensive for larger
plants.

     Figure 51 suggests that another option that needs to be explored is
that of regional reactivation.  Regional reactivation consists of transport-
ing the exhausted carbon to a central site where a reactivation furnace is
located.  This approach, which is particularly appropriate for small plants,
will be explored in the following section.

Regional Reactivation

     For the purposes of this analysis, three sets of regional reactivation
conditions will be examined:

1.   Regional reactivation systems consisting of off-site reactivation plants
     capable of processing carbon from the equivalent of 31001b/day,

                                      74

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                                DISPOSED CARBON COST
1 5 10
      100
PLANT SIZE (MGD)
                                                 150
FIGURE 51. TOTAL UNIT COSTS VERSUS PLANT SIZE
                              75

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     6200 Ib/day, 15,500 Ib/day, 31,000 Ib/day, and 62,000 Ib/day reactiva-
     tion facilities.   These systems will be designated RP ,  RP9, RP~, RP/»
     and RP,., respectively.

2.   Costs for individual plants shipping to these systems will be examined,
     based on the assumption that a number of plants are sharing these
     reactivation systems simultaneously.  For example, the cost in c/1000 gal
     for a 1 mgd plant shipping carbon to a RP.. and RP?, and a 10 mgd plant
     transporting carbon to a RP, and RP- system will be calculated assuming
     that the various  regional off-site reactivation systems are being used
     to capacity.

     By transporting carbon to a regional reactivation center a small plant
is able to take advantage of the economies of scale inherent in a larger
reactivation furnace,  although there is a debit associated with the trans-
portation cost required to gel: the carbon to the site.  The assumptions
regarding the operation of the plants are the same as those in Table 9 (for
example, 70 percent load factor and 1.4 months between reactivation).  The
costs associated with  the water treatment plant will be as follows:  the
initial activated carbon purchase (twice the capacity of the treatment plant,
as one batch of carbon is being reactivated while the other is in place)
and the make-up carbon (loss assumed at 10 percent per replacement cycle due
to handling); transportation costs, which will be assumed as $ . 10/ton-mile,
and a proportionate share of the off-site reactivation costs which will
consist of furnace capital and operating costs, assuming a 10 percent loss
of activated carbon during the reactivation process.  Table 13 contains the
costs associated with  the initial carbon cost, and the carbon loss as well
as the equivalent carbon reactivation requirements per day in Ib/day for
each plant size.  Figures 52 and 53 show the total construction and operating
costs for an off-site  reactivation furnace based on Ib/day of reactivation.
It is assumed in this  analysis that the Amortized Capital and 0 & M costs for
reactivation system are divided equally among the number of plants shipping
carbon to it.  For example, if five 1 mgd plants are shipping to an RP
system, the cost will  be higher than if ten 1 mgd plants are shipping
carbon to RP,., system.

     Transportation costs are calculated as follows for a 1 mgd plant
shipping carbon to a reactivation plant for a 30-mile round trip:
Transport (lOC/ton-mile) (865 cu ft) (30 miles) (30 Ib/cu ft) C-^^) (8.57 react/yr)
Cost   =  -- - • -- --
                        (365 days)(l mgd) (0.70)

       =  .1310/1000 gal (30-mile round trip)

On a per-gal-mile basis, the cost is

     C /gal-mile  =  (.131C/1000 gal) (30 mile)

                 =  . 0044C/1000 gal-mile
                                      76

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TABLE 13.  CARBON COSTS AND REACTIVATION REQUIREMENTS FOR REGIONAL
                         REACTIVATION SYSTEMS
Plant Size
(mgd)
1
5
10
100
150
Initial Carbon
Requirements
(lb)
51,900
259,500
519,000
5,190,000
7,785,000
Annual Cost
($)
1,861.4
9,307.1
18,614.1
186,141.3
279,212.0
Make-up
Carbon
($)
7,254
35,319
69,835
672,321
1,001,758
Reactivation
Requirements
(Ib/day)
617.86
3,089.29
6,178.57
61,785.71
92,678.56
                                    77

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  3500n
  3000i
  2500-
O
O
O 2000-
CO
O
01500-
z
o
H
O
= 1000-
h-
co
z
o
0  5001
           10000
 30000         50000
REACTIVATION RATE (LB/DAY)
                                                  70000
                                                               90000
      FIGURE 52, CONSTRUCTION COST FOR CARBON REACTIVATION SYSTEM VERSUS

                REACTIVATION RATE
                                     78

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 1000000.
CO
o
0

5100000-
08
o
   10000-1
       100
   1000             1000O

REACTIVATION RATE (LB/DAY)
        FIGURE 53. O&IVI COST FOR CARBON REACTIVATION SYSTEM

                  VERSUS REACTIVATION RATE
                            79

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     The Amortized Capital cost and annual 0 & M cost for the off-site
reactivation systems are shown in Table 14.  These costs can be assigned
equally to the water treatment plants served.  For example, RP.. can serve
five 1 mgd treatment plants and the total cost is divided by five, but for
RP,.,, which can serve 10 1 mgd plants, the total annual cost is divided by 10.
Table 15 contains the flow in mil gal/yr and the total allocated cost plus
the initial activated carbon and makeup costs for each plant reactivation
configuration.  As can be seen from Table 15, the unit cost for a 1 mgd plant
sending carbon to a regional reactivation furnace serving five plants is
higher than for a 1 mgd plant sending carbon to a system serving 10 plants
due to economies of scale in the reactivation system.  Transportation costs
must also be considered as in the following discussion.

     Figure 54 shows the distance-related costs associated with the regional
reactivation system for 1 mgd plants sending carbon to a RP  and RP
reactivation system, as compared to on-site reactivation system, and the
slope of the curve shows that carbon can be transported for many miles before
an on-site system becomes cost effective.  Figures 55 and 56 show similar
conditions for 5 mgd plants and 10 mgd plants transporting to RP_ and RP  ,
and RP, and RP  systems, respectively.  It can be seen that for a 10 mgd
plant it also is cost effective to transport spent carbon over relatively
long distances, however, the gap between on-site and transporting off-site
narrows at this level.  Figure 57 shows the impact of variations in trans-
portation cost on the total cost of a 10 mgd plant transporting waste to
a RP, system.

     An alternative to replacing carbon in the filter shell is to build
separate carbon contactors as ah integral part of the treatment system.
A discussion of this option is presented in the following section.

Separate Contactor System

     In the discussion to this point the costs presented have been based on
the assumption that carbon would replace sand in a filter plant.  Therefore,
no Amortized Capital and 0 & M costs associated with separate carbon con-
tactors have been included in the analysis.  It is very likely that operating
in such a manner is inconvenient and inefficient, causing higher carbon
losses due to excessive handling.  A contactor system may be tailored specif-
ically for a given treatment plant operation.  The assumptions used for the
contactor system analysis are as follows (Table 16):  two contactors connected
in series, a contact time of nine minutes and a corresponding recycle
frequency of one-per-2.8 months, bed depths of 20 ft, and a carbon loss of
5 percent per reactivation cycle.  Figure 58 compares the costs for a separate
contactor system versus replacement of carbon as filter media.

     Replacing sand by carbon represents a short-term possibility for water
treatment plants with low capital investment but high operating costs.  A
separate contactor system represents a longer term and permenent solution
with higher capital investment requirements but with lower operating costs
as shown in Table 17.  These capital investment requirements are discussed
in the following section.


                                      80

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TABLE 14.  AMORTIZED CAPITAL AND OPERATING COSTS FOR OFF-SITE REACTIVATION
                                 SYSTEMS
Reactivation
System
RP1
RP2
RP3
T?"P
A
c.
Reactivation
Requirement
(Ib/day)
3,089.27
6,178.57
15,446.35
30,892.85
61,785.71
Construction
Cost
($)
700,000
820,000
1,350,000
1,630,000
2,200,000
Amortized
Capital Cost
($)*
66,080
77,408
127,440
153.872
207,600
Annual
0 & M Cos
($)
180,000
240,000
460,000
750,000
1,130,000
* 7 percent interest, 20-yr amortization period.
                                     81

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TABLE 15.  REACTIVATION SYSTEMS COST FOR AN INDIVIDUAL PLANT
Regional Reactivation
..-.
Regional
Reactivation
Configuration
1 - RP
1 - RP2
C __ "Dp
5 - RP4
10 - RP.
4
10 - RP5

Total No.
of
Plants
Flow per Plant
(mil gal/yr)
5 225
10 225
5
10
1277.5
1277.5
5 2555.0
10

2555.0

Total Annual
Cost
($)
56,470.00
38,995.00
162,114.10
135,013.10
269,321.0
222,217.1

Unit Cost
(0/1000 gal)
25.1
17.3
12.7
10.6
10.5
8.7

                               82

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   70
   60
~ 50
O
o
2  40
8  30
o
=>  20

t-
z
   10
ON SITE REACTIVATION COST
    I-RP-I
  •      •
    I-RP2
     0      20     40     60     80     100    120    140    160    180   200
                           DISTANCE TRAVELED (MILES)

     FIGURE 54. COST OF TRANSPORTING CARBON FROM A 1 MGD PLANT TO REGIONAL
               REACTIVATION SITE VERSUS DISTANCE IN MILES
                                   83

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  70
  60
  50
o
o
o
  40

i-
V)
o
o

t 30

z
ID
o 20
                              ON SITE REACTIVATION
  10'


                        5-RP3
                                        5-RP4
    0     20     40    60     80    100    120    140    160    180    200

                          DISTANCE TRAVELED (MILES)



     FIGURE 55.  COST OF TRANSPORTING CARBON FROM A 5 MGD PLANT TO REGIONAL


               REACTIVATION SITE VERSUS DISTANCE
                                   84

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  70
  60
<50
O

O
o
o

7^40
o

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H

Z
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<20-|

O


                          ON SITE REACTIVATION COST
  10
                   10-RP4               10.Rp5'
   0      20     40     60     80     100    120    140    160    180    200

                        DISTANCE TRAVELED (MILES)


    FIGURE 56. COST OF TRANSPORTING CARBON FROM A 10 MGD PLANT TO REGIONAL

              REACTIVATION SITE VERSUS DISTANCE IN MILES
                                   85

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ON SITE REACTIVATION
            40     60     80    1OO    120    140    160    180    200
FIGURE 57. THE SENSITIVITY OF REACTIVATION COSTS TO TRANSPORTATION
          COST VARIATIONS
                               86

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          TABLE 16.  ASSUMPTIONS FOR SEPARATE CONTACTOR SYSTEMS
Item
Number of Contactors
Hydraulic Loading (gal/min/sq ft)
Diameter Contactors (ft)
Depth of Contactors (ft)
Vol. of Granular Activated Carbon
per Contactor (cu ft)
Apparent Contact Time (min)
Plant Capacity (mgd)
1
2
4
8
13

653.1
9
5
4
.87 5.
12
13

1469.5
9
10
8
42 5
12
13

1469.5
9
100
28
.42 5.
20
14

4396.0
9
150
42
57 5.57
20
14

4396.0
9
Reactivation Frequency (months)
  at 70 percent Capacity              2.8     2.8      2.8      2.8     2.8

Activated Carbon Loss/
Reactivation (percent)                55555
                                     87

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  70-,
  60
o
o
o
  40
CO
o
o
  30-
  20
  10
CONTACTOR SYSTEM
                         FILTER MEDIA REPLACEMENT
          20     40     60     80    100    120

                           PLANT SIZE (MGD)
                     140
                            160
180
200
    FIGURE 58. COMPARISON OF COSTS BETWEEN CONTACTOR SYSTEM AND MEDIA

               REPLACEMENT VERSUS PLANT CAPACITY
                                   88

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TABLE 17.  AMORTIZED CAPITAL AND 0 & M COSTS FOR CONTACTOR VERSUS FILTER
                      MEDIA REPLACEMENT (c/1000 gal)
System ' 1 mgd
Media Replacement 19 . 5
Contactors
Media Replacement
Contactors
Media Replacement
Contactors
30.2
21.5
16.1
41.1
46.3
5 mgd 10 mgd
Amortized Capital
5 3.5
10.2 8.2
100 mgd 150 mgd
Costs
1.5 1.1
4.3 4.1
Operating and Maintenance Costs
10.5 8.2
7.3 5.4
Total Cost
15.5 11.7
17.5 13.6
4.5 4.0
2.4 2.2
6.0 5.1
7.3 6.3
                                     89

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Capital Investment

     All of the cost data presented to this point in the analysis have been
in terms of unit costs (including Amortized Capital and 0 & M costs).   It is
important to present a different perspective by examining total investment
costs.  Separate contactor systems, as can be seen from Table 17, are more
capital intensive then replacing the filter media by activated carbon.  To
build these systems, utilities must raise considerable amounts of initial
capital.  Table 18 summarizes for 1, 10, and 100 mgd plants the principal
and total payback costs required for both types of GAG systems.

     A major part of the capital investment for an on-site reactivation
system is the furnace.  Table 19 summarizes the estimated cost of these types
of furnaces.
                                   TABLE 19


ESTIMATED CONSTRUCTION COST OF GRANULAR ACTIVATED CARBON REACTIVATION FURNACES

Furnace Type                      Capacity              Estimated Total Cost

Multiple-Hearth                 5,000 Ib/hr               $4.2 million

Infrared*                       5,000 Ib/hr               $0.8 million

Rotary Kiln                     5,000 Ib/hr               See note

Fluidized Bed*                  5,000 Ib/hr               $1.2 million

* Because furnaces of this size have not been manufactured, these estimates
    are very preliminary.

Note:  Insufficient information is available to estimate a cost for this
         type of furnace.
Labor Costs for GAG Systems

     The previous analysis points to one salient fact regarding the use of
granular activated carbon.  Unit costs for small plants reactivating on-site
may be prohibitively expensive.  It is obvious that plants in the 1 mgd
design capacity should consider off-site reactivation in a regional facility.

     All of the previous cost evaluations have been made for critical design
conditions, such as a once-per-1.4 month reactivation cycle and capacity
factors below 100 percent.  These data have been computed for isolated
systems.  In a total treatment complex, however, there may be opportunities
to share labor among several activities.  For example, the laborers assigned

                                     90

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to groundskeeping or general labor might be utilized in the reactivation
activity.  Such a joint use of labor might realize genuine savings, particu-
larly in a small plant.  Table 20 displays the percentage of total costs
for plants with on-site reactivation which is made up of labor costs.   It can
be seen that for small plants with on-site reactivation, labor costs account
for over 40 percent of the total cost.

SUMMARY AND CONCLUSIONS

     It is obvious from the data presented in this report that chlorination
is the cheapest of all of the treatment technologies that might be used for
disinfection.  Table 21 summarizes the values for a 1, 5, 10, 100, and 150
mgd plant for all of the treatment alternatives examined in this report.

     As chlorination under certain conditions causes chloroform, a potential
carcinogen, in drinking water, planning and operating agencies must examine
alternatives to the chlorination process.  These alternatives might take the
form of disinfection techniques other than chlorination, or of trihalomethane
removel techniques such as aeration, or of organic removal techniques such
as granular activated carbon.  Hopefully, this report will assist in making
these evaluations.
                                      92

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TABLE 20.  LABOR COSTS FOR 1, 10, and 100 mgd GAG SYSTEMS REACTIVATING
                    ON-SITE (FILTER SHELL REPLACEMENT)
Plant
Capacity
5
10
100
Capacity
Factor
-7
• i
.7
.1
Total Cost
$/yr
199,915.97
302,103.2
2,098,677.0
Labor Cost
$/yr
91,385
124,724
421,756
Percent
Labor Cost
46
41
20
                                 93

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                                 REFERENCES
1.   Breidenbach, Andrew W., "Regulations:  Reactions and Resolutions,"
     Journal of the American Water Works Association, Vol. 68, No. 2,
     February 1976, pp. 77-82.

2.   Bureau of Labor Statistics, "Chapter 11.  Wholesale Prices," reprint
     from the BLS Handbook of Methods (BLS Bulletin 1711), U. S. Department
     of Labor, pp. 97-111.

3.   Eilers, Richard G., and Smith, Robert, "Executive Digital Computer
     Program for Preliminary Design of Wastewater Treatment Systems,"
     November 1970, NTIS-PB222765 (report  NTIS-PB222764 (card deck).

4.   Fair, Gordon Maskew, and Geyer, John Charles, "Elements of Water Supply
     and Waste Water Disposal," John Wiley & Sons, Inc., New York, pp. 480-481.

5.   Federal Water Pollution Control Administration, "Sewer and Sewage
     Treatment Plant Construction Cost Index," U. S. Department of the
     Interior, Washington, D. C. 20242.

6.   Finerty, Joseph M. (Editor), Employment and Earnings, April 1976,
     U. S. Department of Labor, Bureau of Labor Statistics, Vol. 22, No. 10.

7.   Love, 0. T., et al., "Treatment for the Prevention or Removal of
     Chlorinated Organics in Drinking Water," submitted for publication to
     the Journal of the American Water Works Association.

8.   Miltner, R. J., "The Effect of Chlorine Dioxide on Trihalomethane in
     Drinking Water," Master of Science Thesis, University of Cincinnati,
     1976.

9.   Patterson, W. L.,  and Banker, R. F., "Estimating Costs and Manpower
     Requirements for Conventional Wastewater Treatment Facilities for the
     Environmental Protection Agency," Black and Veatch, Consulting Engineers,
     Kansas City, Missouri, 1971.

10.  Quarles, John R.,  Jr., "Impact of the Safe Drinking Water Act,"
     Journal of the American Water Works Association, Vol.  68, No. 2,
     February 1976, pp. 69-70.

11.  Suindell-Dressler, "Process Design Manual for Carbon Adsorption,"
     U. S. Environmental Protection Agency, Technology Transfer, October 1973.


                                     95

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12.   Symons, James M.,  "Interim Treatment Guide for the Control of Chloroform
     and Other Trihalomethanes," June 1976,  Water Supply Research Division,
     Municipal Environmental Research Laboratory, Office of Research and
     Development, Cincinnati, Ohio  45268, pp.  4-6.

13.   Ibid, pp. 1-4.

14.   Ibid, pp. 6-30.
                                      96

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
 1 REPORT NO.
  EPA-600/1-77-008
                                                           3 RECIPIENT'S ACCESSION-NO.
 4 TITLE AND SUBTITLE
  THE  COST OF REMOVING CHLOROFORM AND OTHER TRIHALO-
  METHANES FROM DRINKING WATER  SUPPLIES
             5. REPORT DATE
                March 1977  (Issuing  Date)
             6. PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
  Robert  M.  Clark, Daniel L. Guttman,  John L. Crawford,
  John  A.  Machisko
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Same as  below
                                                            10. PROGRAM ELEMENT NO.

                                                              1CC614
                                                            11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
  Municipal  Environmental Research  Laboratory—Cin.,OH
  Office  of  Research and Development
  U. S. Environmental Protection  Agency
  Cincinnati.  Ohio  4S?(SR	__^
                                                            13. TYPE OF REPORT AND PERIOD COVERED
                                                              In-house
             14. SPONSORING AGENCY CODE

                EPA/600/14
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT

  This  research effort was conducted to provide an  in-depth examination of  the costs
  associated with the use of activated carbon, ozonation,  aeration, and chlorine
  dioxide  for removal of trihalomethanes.

  The costs  presented in this report are intended for the  development of planning
  estimates  only and not for the preparation of bid documents or detailed cost  esti-
  mates.   Exact capital and operating costs are highly variable from location  to
  location within the United States,  even  for plants of  the same size and design.
  These costs are presented in such  a way  as to enable the planner to make  adjustments
  to the reported costs when local information in available.   Standardized  levels  for
  a selected  set of  design parameters are  assumed and sensitivity analysis  is  performed
  for the  majority of the parameters.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.IDENTIFIERS/OPEN ENDED TERMS
                           c. COS AT I Field/Group
  Activated  carbon treatment; Aeration;
  Chlorination;  Chloroform; Economic Analys:
  Filtration;  Operating Costs; Regeneration
  (Engineering)
   Chlorine dioxide;
   Capital costs;  Ozona-
   tion; Trihalomethane
   removal; Unit process
   costs.
   13 B
   14 A
13. DISTRIBUTION STATEMENT
  Release  to  public
19. SECURITY CLASS (This Report)
   Unclassified
21. NO. OF PAGES
   116
                                              20. SECURITY CLASS (This page)
                                                 Unclassified
                                                                         22. PRICE
EPA Form 2220-1 (9-73)
                                            97
                                                    U S GOVERNMtNl rmnnnu UMI..I. I3//-/57-056/5488 Region No. 5-1

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