EPA-600/2-76-293
December 1976
Environmental Protection Technology Series
iCONOMIC ASSESSMENT OF WASTE WATER
AQUACULTURE TREATMENT SYSTEMS
Robert S. Kerr Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
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 consciously
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 PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-76-293
December 1976
ECONOMIC ASSESSMENT OF WASTE WATER
AQUACULTURE TREATMENT SYSTEMS
by
Upton B. Henderson
and
Frank S. Wert
Department of Economics
Central State University
Edmond, Oklahoma
In Consultation With
Ron Jarman
and
Settle, Dougall and Spear Engineering
Grant Number R803623
Project Officer
William R. Duffer
Wastewater Management Branch
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental
Research Laboratory, U. S. Environmental. Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policies of the U. S. Environmental Protection Agency, nor
does mention of trade names or commercial products constitute endorsement or
recommendation for use.
ii
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ABSTRACT
This study attempted to ascertain the economic viability of aqua-
culture as an alternative to conventional waste water treatment systems
for small municipalities in the Southwestern region of the United
States. A multiple water quality objective level cost-effectiveness
model was employed. A total of fifteen waste water treatment strate-
gies, eleven with aquaculture systems and four without aquaculture, were
examined. Estimates were made of the technical effectiveness and the
present value of costs for all strategies. Estimates of the current
value of revenues derived from sale of products produced in the aqua-
culture systems were made, and the impact of such revenues on total
costs was analyzed.
In all cases, when aquaculture was deemed capable of achieving a
given water quality objective, the aquaculture system compared to a
conventional system was cost-effective. The cost differentials between
aquaculture and conventional strategies were highly significant ranging
from a low 3.8 percent to a high of 94 percent. While certain data
limitations exist, especially in the area of water quality estimates,
aquaculture systems appear to be low cost alternatives to conventional
waste water treatment systems.
This report was submitted in fulfillment of Grant Number
R803623-01-0 by Central State University under the sponsorship
of the Environmental Protection Agency. Work was completed as
of July 30, 1976.
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CONTENTS
Page
Abstract iii
List of Figures vi
List of Tables vii
Acknowledgments viii
Conclusions ix
Recommendations xi
INTRODUCTION
Background and Purpose 1
State of the Arts of Aquaculture 4
Cost-Effectiveness as a Tool of Analysis 10
RESEARCH DESIGN AND METHODOLOGY
Strategy Design and Selection -. 14
Cost Methodology 19
Estimation of Aquaculture Parameters 24
Aquaculture Revenue Calculations 38
COST DATA AND EVALUATION
Systems Costs 44
Cost-Effective Systems 58
DISCUSSION
Work Performed 75
Problem Areas 76
Summary and Conclusions 79
BIBLIOGRAPHY 85
APPENDIX 91
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FIGURES
No. Page
1 Stage Processes for Alternative Strategies 16
2 Strategy Matrix 19
3 The Cost Matrix Model 22
vi
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TABLES
No. Page
1 Typical Polyculture System 27
2 Estimated Fish Output From the Various Aquaculture
Strategies 30
3 Annual Stocking Rates for Monoculture 33
4 Annual Stocking Rates for Polyculture 34
5 Absolute Levels of Pollutants by Strategy and Stage 35
6 Current Fish Prices 41
7 Estimated Total Annual Revenue From Aquaculture Output ... 43
8 Present Value of Estimated Costs by Category, Strategy
and Stage 45
9 Estimated Aquaculture Operating Costs Excluding Stock ... 51
10 Estimated Cost of Stock for Monoculture by Strategy and
Species 52
11 Estimated Cost of Stock for Polyculture by Strategy and
Species 53
12 Estimated Annual Net Revenues From Aquaculture 55
13 Discounted Values for Annualized Stream of Net Revenues
by Strategy for Species Yielding the Highest Net Revenues 56
14 Non-Monetary Factors Associated With Each Strategy 59
15 Cost-Effective Systems to Achieve Alternative Objective
Levels of BODs and Suspended Solids 60
16 Cost-Effective Systems to Achieve Alternative Objective
Levels of Phosphorus and TKN 63
17 Classification and Analysis of Effluent Quality 65
18 Cumulative Percent Reduction of Pollutants, by Strategy
and Stage 69
19 Rank Order of Strategies by Cumulative Costs and Stages . . 71
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ACKNOWLEDGMENTS
This research, Grant Number R803623-01-0, was made possible by a
grant from the Environmental Protection Agency to Central State Univer-
sity, Edmond, Oklahoma. Dr. William Duffer, Wastewater Management
Branch, Robert S. Kerr Environmental Research Laboratory, Ada, Oklahoma,
served as Project Officer. Dr. Duffer provided continued support and
excellent advice and guidance throughout the duration of the project.
Dr. R. LeRoy Carpenter, Commissioner of Health, Mr. Mark Coleman,
Assistant Deputy Commissioner for Environmental Health Services and
other members of the Oklahoma State Health Department were responsible
for the pioneering effort in waste water aquaculture in the State of
Oklahoma and provided invaluable information and support needed to
cumplete this project.
The success of this project was dependent upon the support and
cooperation of the Administration of Central State University. In addi-
tion, we wish to acknowledge many fish culturists who provided excellent
insights essential to this project. The authors, of course, are solely
accountable for any errors or omissions contained in this report.
vvn
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CONCLUSIONS
• 1. When the ability to reduce suspended solids and 8005 was con-
sidered, aquaculture strategies were always more cost-effective than
corresponding conventional alternatives when aquaculture was capable
of achieving the desired level of BODs/SS removal. The cost differen-
tial between aquaculture and conventional strategies ranged from a low
of 3.8 percent to a high of 72 percent.
2. The aquaculture system was again more cost-effective in: meet-
ing nutrient removal goals when aquaculture was capable of achieving
given P/TKN objectives. The cost differentials ranged from a low of
38 percent to a high of 94 percent.
3. The most cost-effective strategy to meet current secondary
standards is Strategy 2, Waste Stabilization Lagoon with Aquaculture
Lagoon.
4. The most cost-effective strategy to meet advanced treatment
standards is a conventional system, Strategy 12, Activated Sludge—
Carbon Sorption—Ammonia Removal System. This conclusion is very tenta-
tive because of the lack of adequate information on the ability of
aquaculture to meet these more rigorous standards.
5. The potential revenues generated from aquaculture were not
critical to the economic cost-effectiveness of aquaculture. The rela-
tive ranking of the various strategies was unaffected by the assumption
of zero revenues from aquaculture.
6. Although this study raises as many questions as it answers,
waste water aquaculture is definitely a low cost alternative to
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conventional treatment technology and should be given serious consid-
eration at this time as an economically feasible treatment system.
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RECOMMENDATIONS
Water quality efficiencies and aquaculture production capabilities
are not well documented. It is recommended that controlled studies be
initiated to ascertain the relative efficiency of varying species of
fish and polyculture in terms of water quality. Variation in water
quality may result, among other parameters, from different retention
rates, seasonal variation in species, species composition, nutrient
loading and size of fish when harvested. The effect of these variables
should be documented.
It is further recommended that studies on the markets and market-
ability of aquaculture products be initiated. Such studies should
include health considerations, alternative uses of products, size and
strength of markets, and susceptibility to change. In addition, studies
should ascertain the full opportunity costs of nutrients contained in
waste water including the entire array of alternatives such as man-made
marshes, land recycling, aquaculture lakes and lagoons and the possi-
bility of integrated systems.
Although this study raises additional questions that need to be
answered, it is nonetheless recommended that small municipalities cur-
rently give serious consideration to aquaculture wastewater treatment
systems to exceed current secondary treatment standards and to reduce
nutrient levels.
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INTRODUCTION
BACKGROUND AND PURPOSE
Small communities across the nation are currently confronted with a
serious economic and financial dilemma since they must meet minimum
waste water treatment standards specified by the Federal Water Pollu-
tion Control Act as amended in PL 92-500 by the year 1977. Some of
these communities are currently operating treatment facilities which
do not meet defined secondary treatment standards. This deficiency
will, in many cases, require construction and operation of more advancec
treatment systems, and hence will require a substantial new commitment
of community and Federal resources.
In small communities, the problem of meeting this commitment is com-
pounded by: 1) a weak tax base, 2) eroding political support for
environmental quality, 3) a lack of adequate technical knowledge to
comply with environmental standards in the most economical manner, and
4) greatly inflated construction and operational costs. In addition,
the sharply rising costs of conventional waste water treatment with
respect to effluent quality create an additional barrier to complete
and full compliance.
One technical alternative to conventional advanced waste water treat-
ment systems is a culture of biological organisms within the system,
or aquaculture. Since aquaculture systems in waste water are currently
in the experimental stage of development, there is very little
known about the economic feasibility of such systems serving as substi-
tutes for the advanced conventional systems. This study will move
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toward filling this void and providing small communities and
consulting engineers with relevant economic data upon which to base
decisions.
The laws of conservation of matter obviously apply to the treatment of
municipal waste water. The objective of treatment processes is to
change the nature of the mass so that it can be reintroduced into the
biosystem with the least possible-disrupt!* on (Kneese, Ayres, et al,
1970). However, since the treatment process itself introduces new
materials and energy inputs, the resulting mass increases and necessi-
tates an ever larger mass to be disposed of. The principles of an
aquaculture system are to not only facilitate disposal of the mass,
but to actually transform the mass from a nuisance to a usable product--
fish.
The objective of this project is to analyze and compare the costs and
effectiveness of conventional waste water treatment systems with the
costs and effectiveness of aquaculture waste water treatment systems
for small communities with specific reference to small municipalities
in the Southwest region of the United States.
To accomplish this objective the project will:
1. Determine the technical effectiveness of conventional systems with
respect to effluent quality.
2. Determine the costs of conventional systems with respect to effluent
quality.
3. Determine the technical effectiveness of aquaculture systems with
respect to effluent quality.
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4. Determine the costs of aquaculture systems with respect to the
level of effluent quality.
5. Estimate the potential economically feasible by-products of aqua-
culture systems and associated revenues.
6. Construct an economic model to compare the cost effectiveness of
the various stages of conventional treatment systems and aquaculture
systems.
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STATE OF ARTS OF AQUACULTURE
The practice of utilization of human waste for production of aquaculture
output is as old as the recorded history of mankind (Allen, 1970). The
ancient oriental ricepaddy-carp-waterchestnut village culture is an
example of an integrated waste disposal food production system.
The possibility of achieving low cost and effective water pollution
control through an integrated mechanical-chemical-aquaculture system
has only recently received attention in the United States (Colernan,
e£jil_). Although it has been recognized that water pollution control
embraces a wide collection of devices or actions, sanitary engineers
have placed emphasis on "sewage treatment" or "waste treatment." These
practices involve an "end of pipe" treatment approach which either con-
centrates wastes or changes the form to less harmful and environmentally
damaging material. Mechanical, chemical, and energy intensive tech-
nology has eminated from this approach to "sewage treatment," and the
total mass of unwanted by-products is therefore increased (Kneese,
Ayres, e£al_, 1970). Aquaculture as an alternative has much theoretical
appeal because it can convert a large percentage of waste water contam-
inants to useful products. Greater utilization of natural systems such
as aquaculture to achieve pollution control will tend to reduce energy
and other inputs to achieve a given level of water quality. Both of
these factors .would, at least theoretically, reduce the cost of achiev-
ing a given level of water pollution control. Aquaculture systems,
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because of susceptibility to biological disruption, may more quickly
bring about the need for recognization of effective "front end of pipe"
water pollution control. If aquaculture treatment systems become widely
used, the prevention of the introduction of toxic pesticides, heavy
metals, and P.C.B.'s into municipal waste water disposal systems will
become critical. The adoption of such controls may, in fact, result
in better water quality at lower overall costs. Effective water pollu-
tion control using natural systems requires a more integrated approach
for both "end-of-pipe" and "front-end-of-pipe" controls.
Many existing waste treatment facilities in the United States could
easily convert to aquaculture with small additional costs. These addi-
tional costs might be more than offset by the market value of aquacul-
ture products and possible gains may result from improved water quality
and reduction in sludge handling and unwanted by-products of treatment.
The major obstacle to aquaculture as an acceptable and economically
feasible alternative in treatment strategies is the current lack of
assurance that those systems can continuously meet mandated water qual-
ity standards (Reid, 1975). In an effort to address these critical
problems the Environmental Protection Agency has funded several
research programs in waste water aquaculture. The bulk of this effort
is directed toward determining the best species, or combination of
species, of animal and plant life to 1) achieve mandated water quality
parameters, and 2) to produce marketable products in order to minimize
treatment costs. Research efforts need to be expanded to establish the
reliability of aquaculture systems and to determine the maximum
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efficiency of various aquaculture alternatives.
Aquaculture alternatives appear to be attractive for the control of
suspended solids in the form of algae (Carpenter, ert al_, 1974), as
oxidation lagoons currently in operation fail to meet present secondary
treatment standards for suspended solids. Control of algae by aquatic
animals may be obtained in several ways. A food chain may be estab-
lished in a waste water lagoon where species at the bottom of the food
chain consume algae and in turn are consumed by larger predatory species
which can be harvested and sold in commercial markets. Another alter-
native would be to utilize algae feeders directly as a source of revenue
production. These organisms feed on algae either by straining the
water forced through them as they swim or by remaining stationary and
pumping water through their algae straining device. While the impact
on water quality of such biological activity has not been firmly estab-
lished, this type of system has great theoretical potential and should
be thoroughly examined, including documentation of species susceptibility
to biological disruption and the effects of climatic conditions on treat-
ment processes.
A number of common species of fish of the Southwestern region of the
United States may be suitable for aquaculture treatment systems. While
scientific documentation is currently lacking, channel catfish, minnows,
largemouth bass, buffalo, carp, and possibly gizzard shad or paddlefish
appear to be feasible for waste water aquaculture systems. Marketability
of these species could be confined to fish fingerlings for restocking
purposes, bait fish, pet food, fertilizer or other non-human consumption
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uses. Prospects of production of fish for human consumption remain
a possibility if health implications are resolved and public acceptance
is achieved.
Several exotic aquatic organisms may be effective in achieving water
quality parameters from waste water aquaculture systems. The desirable
organisms must be algae feeders and be capable of achieving a rapid
rate of growth. Considerable experimentation on the use of an African
fish, Tilapia, has been undertaken in Oklahoma. The primary disadvantage
of this exotic species is its susceptibility to biological disruption
caused by low water temperatures occurring in non-tropical waters.
Another group of species with ability for algae removal is shellfish.
Although less work has been done with these organisms, they may provide
a more controllable situation of waste water control than free swimming
species. It is easy to visualize baskets of clams being moved from
lagoon to lagoon as needed to reduce algal blooms. Fish, of course,
could also be caged and moved in this manner. Other animals which show
promise and may be studied in the future are frogs, turtles, shrimp
(fresh water variety) and prawns. All these species might be feasible
alternatives but little is known about their effectiveness in achieving
water quality.
The range of alternatives is not confined to aquatic animal organisms.
It is definitely possible that higher aquatic plants (vascular) may be
extremely effective in waste water treatment. Most aquatic plants grow
rapidly and are easily harvested. Two problems concerning their use
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have arisen. One is the lack of a market value for the product and
two is the restrictive seasonal growth in the Southwestern region of
the United States.
It may be very desirable to consider alternatives to the monoculture
situation in favor of combinations of species of plants and/or animals
in an integrated system. A properly designed system could theoretically
remove a much larger portion of waste products than could monoculture
due to the various ecological niches which occur in waste water systems.
This may also result in an array of output which would be less suscep-
tible to market fluctuations than a monoculture system. Social benefits
in the form of recreation may also be achieved (Hallock, e_t al_» 1970).
Climatic variation is an extremely important factor in planning an
aquaculture system. Virtually all aquatic organisms are poikilothermic
in that their body temperature is the same as the surrounding
environment. As temperature decreases metabolic activity decreases.
This may reach a point in the winter where virtually no biological
activity is occurring and at the same time waste water loads are accumu-
lating. The result would be poor water quality and a violation of
mandated standards. It may be possible to provide a set of organisms
in a polyculture which would overcome this difficulty. Seasonal varia-
tion on the effectiveness of aquaculture systems cannot be overlooked.
In Oklahoma's climate the normal warm water organism has a growing
season of 180-210 days per year (Clemens, 1970). Standby capacity
would have to be provided to correct this problem with the possibility
of 160 days of standby capacity or alternative treatment.strategy.
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Another significant problem which must be overcome to operate an aqua-
culture system is that existing waste water systems are designed to
treat waste water and not to culture aquatic organisms. This design
characteristic may manifest itself in several areas. An important
factor is the possibility of dissolved oxygen depletions in an aquacul-
ture system. If this occurs the bulk of the aquatic organisms may be
killed and the remaining organisms' activity reduced for a considerable
period of time. This would necessitate re-establishing the population
as well as loss of the aquaculture waste water treatment capacity.
For the aquaculture system to work the organisms produced in the system
must be removed at a prescribed rate. Existing waste treatment facil-
ities are not designed for harvesting of aquatic organisms and present
an important problem in the use of these facilities. In many cases
this will render aquaculture as an unwise alternative due to harvesting
problems. Aquaculture systems must be designed to achieve effective
harvest not only from the aspect of revenue production, but also to
achieve water quality.
Many municipal systems will receive at some point in time a load of
biologically toxic materials. Aquatic organisms are very susceptible
to many of these materials and one exposure could eliminate a one year
crop with the resulting loss of treatment. This problem must be cor-
rected at the "front end of the pipe" or aquaculture systems will be
subject to periodic disruption and possible concentration of toxic
material within the organisms rendering them unfit for sale.
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A final design factor which could influence the reliability of aquacul-
ture is the depth of the facility. Most aquatic organisms are effective
only close to the water surface. Large amounts of very deep water may
greatly reduce the efficiency of the aquaculture system in treating
the waste load. Therefore, aquaculture systems tend to require larger
land units than some conventional alternatives.
The culture of most aquatic organisms is a highly technical and demand-
ing profession. Considerable technical expertise is required for
successful culture even under the best of conditions. In the small
municipalities it may be beyond the capabilities of the budget and/or
highly impractible to employ a fish culturist. However, this problem
might be overcome by employing a fish culturist to manage several waste
water aquaculture systems in a given region.
In summary, the use of aquaculture to treat waste waters is an unsettled
question. It offers theoretical advantages that few other systems have
and has popular support. Whether it will grow to become a major treat-
ment technique will depend on the outcome of current research, the
economic situation for municipalities, and the interest of those active
in the field of waste water treatment.
COST EFFECTIVENESS AS THE TOOL OF ANALYSIS
The private sector of the economy has long applied the principles of
microeconomic theory in decision making. Public investment decisions,
like their counterparts in the private sector, require capital budget-
ing techniques and the use of cost-benefit analyses as a major tool.
The general objective of cost-benefit analysis is to measure the costs
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and benefits derived from social investments. The objective is to
maximize economic efficiency in the allocation of limited public resources.
The maximization of net benefits is achieved when the marginal cost of
a specific investment is equal to the marginal benefits from the invest-
ment. Public projects are deemed economically feasible if their benefits
are equal to or greater than the costs of the project.
Ideally, waste water treatment investment decisions should result from
cost-benefit analysis. However, this type of analysis is not easily
applied to pollution abatement programs because of the nature of the
benefits derived. This type of governmental activity produces a bene-
fit (clean water) that is not usually associated with a market.
Therefore, it is difficult to quantify and attach dollar values to the
benefits derived from clean water. The ta'sk is not impossible, but it
requires the use of indirect-estimating techniques such as: 1) the
observation and measurement of changes in the price of land, or other
complementary goods, affected by the project; 2) the isolation of prices
paid for close substitutes in private markets; and 3) the estimation of
cost reductions made possible in other markets as a result of the
project. While in some cases, indirect measures of willingness to pay
(i.e. demand functions) may be derived, the major identifiable and
measurable benefits derived from improved water quality are: 1) greater
availability of water-based recreation; 2) improvements in commercial
fishing reflected in the harvests or catch; and 3) reduction in costs
of drinking water treatment for cities and towns (Davidson, et al,
1966).
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The alternative to cost-benefit analysis is cost-effectiveness analysis.
Cost evaluations are more direct and easier to obtain using cost-effec-
tiveness analysis because only direct costs are measured. Inputs are
generally obtained from private markets and hence bear readily obtain-
able market prices. Investment decisions and waste water treatment
alternatives or strategies, may be compared given either 1) constant
investment funding, or 2) a given standard of water quality.
Cost-effectiveness studies begin with the premise that some identifiable
project goals are desirable and attainable and proceed to explore 1)
the methods for efficient achievement or 2) costs of achieving various
goal attainment levels.
Cost-effectiveness studies can be categorized into three types (Singer,
1972). The first type is a constant cost study—where an attempt is
made to specify the goal to be achieved from a number of alternative
programs assuming all projects are funded at the same level. The cri-
teria for selection would be the alternative which achieves the highest
goal. The second type is a least-cost study where all possible alter-
natives are examined to achieve a given objective or goal (e.g.,
80 percent reduction in suspended solids). The criteria for selection
is the alternative with the least-cost. The third type is the objective-
level study which attempts to estimate the costs of achieving several
alternative performance levels of the same general goal. For example,
the method estimates the costs of alternative waste water treatment
strategies which would achieve 1) primary standards, 2) secondary stan-
dards, and 3) tertiary or advanced standards. Varying performance
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standards can be evaluated in terms of the least-cost criteria, and a
performance standard could be selected with some knowledge of the cost
trade-offs among alternative goals. The nature of the problem and the
variety of inputs indicate the use of the objective-level study method
of cost-effectiveness for making investment decisions concerning waste
water treatment facilities.
While there are advantages and limitations to the methodology of cost-
effectiveness, the advantages are generally greater than the limitations.
The advantages of cost-effectiveness over cost-benefit analysis are:
1) there is less information required; 2) it is less demanding of time
and resources; and 3) Federal agencies are familiar with its practical
use. The limitations of cost-effectiveness methodology are: 1) there
is no indication of the economic efficiency level of performance or
goals, and 2) it would not be useful in determining choices among
various programs with dissimilar benefits.
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RESEARCH DESIGN AND METHODOLOGY
STRATEGY DESIGN AND SELECTION
This study was conceived to evaluate the potential use of aquaculture
as substitute water treatment processes for more conventional methods.
Therefore, the primary effort was to develop treatment strategies
suitable for relatively small communities which may or may not be cur-
rently meeting waste water quality "standards. The objective in strategy
selection was not to minimize costs, but rather to select a relatively
broad spectrum of feasible treatment strategies for comparative
purposes. The strategies were isolated and costs calculated using the
following assumptions:
1. All systems are designed for municipalities of approximately 2,000
population having an influent flow of 200,000 gal/day.
2. Ultimate discharge is to surface waters.
3. Sludge handling is a function of the type of process employed and
is included as a relevant cost.
4. In the absence of aquaculture, effluent nutrients are lost, and
opportunity costs for the use of nutrients are zero.
5. Revenue functions for aquaculture output are linear, and therefore,
prices are unaffected by output decisions.
6. Salvage value for physical plant and equipment is assumed to be
zero, and the cost of restoring the land to salable condition is
assumed to be equal to the prevailing price of land.
7. The productivity of an aquaculture lagoon or raceway is equivalent
to a fully fertilized fish pond.
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8. The quality of effluent from aquaculture does not vary by aquatic
species.
9. Health considerations are negligible.
10. All products resulting from aquaculture are not sold for human
consumption but are marketable.
Utilizing these assumptions, there was an examination of eleven strate-
gies of municipal sewage treatment taken from a final report for the
Council on Environmental Quality and the E.P.A. Office of Planning and
Evaluation (E.P.A., 1974). In addition, strategies for both conventional
and aquaculture systems for rural municipalities were recommended by
the consulting engineer for this study. Also, the project's biologist
examined other sources, made recommendations and established aquacul-
ture design parameters.
Through working conferences, the economists, the engineer, and the
biologist finally selected fifteen strategies as being appropriate,
technologically feasible, waste water treatment systems to compare for
the size of community under consideration. These strategies include
various combinations of conventional systems, aquaculture raceways, and
aquaculture fish lagoons. Figure I illustrates the "Decision Tree"
upon which selection of alternatives by process, or stage, can be made.
The fifteen strategies include eleven aquaculture systems and four con-
ventional systems. The processes are as follows; schematic illustrations
are in the Appendix. Each Waste Stabilization Lagoon is a two-phase lagoon.
Strategy 1. Waste Stabilization Lagoon with an Aquaculture Raceway
Stage I—Waste Stabilization Pond
Stage II--Aquaculture Raceway
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Primary Screening
Municipal
Waste
Screens and
Primary Sedimentation
Extended Aeration and
Secondary Clarification
Waste Stabilization Pond
Aquaculture
(Directly in Secondary Lagoon)
Trickling Filter and
Secondary Sedimentation"
Activated Sludge
Chemical Addition
Activated Sludge
Aquaculture Raceway
Aquaculture Lagoon
Aquaculture Raceway
Aquaculture Lagoon
Coagulation Filtration
Aquaculture Raceway
Aquaculture Lagoon
Aquaculture Raceway
Aquaculture Lagoon
Aquaculture Raceway
Aquaculture Lagoon
Carbon Sorption——NH- Removal
Coagulation Filtration
Ni tri fi cati on/Den i tri f i cati on
Figure 1. Stage Processes for Alternative Strategies
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Strategy 2. Waste Stabilization Lagoon with an Aquaculture Lagoon
Stage I—Waste Stabilization Pond
Stage II--Aquaculture Lagoon
Strategy 3. Waste Stabilization Lagoon with Fish Grown Directly in the
Secondary Lagoon
Stage I—Waste Stabilization Pond with Aquaculture
Lagoon
Strategy 4. Trickling Filter with Aquaculture Raceway
Stage I—Primary Treatment
Stage II—Trickling Filter with Secondary Sedimentation
Stage III—Aquaculture Raceway
Strategy 5. Trickling Filter with an Aquaculture Lagoon
Stage I—Primary Treatment
Stage II—Trickling Filter with Secondary Sedimentation
Stage III—Aquaculture Lagoon
Strategy 6. Activated Sludge with an Aquaculture Raceway
Stage I—Primary Treatment
Stage II—Activated Sludge
Stage III—Aquaculture Raceway
Strategy 7. Activated Sludge with an Aquaculture Lagoon
Stage I—Primary Treatment
Stage II—Activated Sludge
Stage III—Aquaculture Lagoon'
Strategy 8. Activated Sludge, Chemical Addition, with an Aquaculture
Raceway
Stage I—Primary Treatment
Stage II—Activated Sludge with Chemical Addition
Stage III—Aquaculture Raceway
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Strategy 9. Activated Sludge, Chemical Addition, with an Aquaculture
Lagoon
Stage I—Primary Treatment
Stage II—Activated Sludge with Chemical Addition
Stage III--Aquaculture Lagoon
Strategy 10. Activated Sludge with Nitrification/Denitrification
Stage I—Primary Treatment
Stage 11—Activated, Sludge
Stage III—Nitrification/Denitrification
Strategy 11. Activated Sludge with Coagulation Filtration
Stage I—Primary Treatment
Stage II—Activated Sludge
Stage III—Coagulation Filtration
Strategy 12. Activated Sludge with Carbon Sorption, Ammonia Removal
System
Stage I—Primary Treatment
Stage II—Activated Sludge
Stage III—Coagulation Filtration
Stage IV—Carbon Sorption
Stage V—Ammonia Removal
Strategy 13. Extended Aeration with Aquaculture Raceway
Stage I—Extended Aeration with Secondary Clarification
Stage II—Aquaculture Raceway
Strategy 14. Extended Aeration with Aquaculture Lagoon
Stage I—Extended Aeration with Secondary Clarification
Stage II—Aquaculture Lagoon
18
-------
Strategy 15. Waste Stabilization Lagoon with Coagulation Filtration
Stage I—Waste Stabilization Lagoon
Stage II--Coagulation Filtration
COST METHODOLOGY
The various feasible strategies for the treatment of municipal waste
water including both conventional and aquaculture systems were broken
down, by stage, into a Strategy Matrix depicted in Figure 2. The rows
represent all the possible component parts, or stages, for all feasible
strategies (i.e., primary treatment, activated sludge, coagulation fil-
tration, etc.) and columns represent different strategies. An X appears
for each stage used in each column; reading down a column reveals all
the stages of a single strategy (e.g., strategy 3 is comprised of stages
A, D, and N).
STRATEGY
STAGES
A
B
C
D
•
•
•
N
1234
X XX
X
X
X
X X X X
5
x
X
.x
N
X
X
Figure 2. Strategy Matrix
19
-------
If a cost is assigned to each stage or component, following EPA cost-
effectiveness guidelines (Cost-Effectiveness Analysis, 1973), then the
cost function, or model, for each strategy takes the generalized form:
N
Ci = I Xji
Where Ci = Present value of the total cost of the ith strategy,
Xji = The present value of the total cost of the jth component of
the ith strategy.
And can be defined as:
Where Kj = Capital Cost of constructing the jth component,
Oftj = Fixed annual operating and maintenance costs of the jth com-
ponent in time period t, discounted for 20 years.
Ovtj = Variable annual operating and maintenance costs of the jth
component in. time period t, discounted for 20 years.
Rtj = Annual revenue derived from sale of output of the jth com-
ponent in time period t, discounted over 20 years (assumed
to be zero for all but aquaculture components).
Sj = The present salvage value of the jth component after 20 years.
r = Discount rate.
Kj capital cost includes the cost of construction, all equipment and
materials, buildings, land, and all engineering charges and interest
during construction.
Oftj, fixed annual operating and maintenance costs includes recurring
expenditures for all labor, materials, and power and fuel used which
is not a function of water flow through the system.
Ovtj, variable annual operating and maintenance costs, includes recurring
20
-------
expenditures that are dependent upon the level of flow through the
system.
Rt is the expected annual revenue derived from the sale of the products
from the aquaculture system.
Sj salvage value was assumed to be zero. The physical plant and equip-
ment were assumed to have no salvage value and the cost of restoring
the land to salable condition was assumed to be equal to the prevailing
sale price of the land.
A discount rate, r, of 5-7/8 percent (EPA, 1975) was used.
The model cost matrix is presented in Figure 3. Costs for each stage
of each strategy were estimated by the consulting engineer on the bases
of EPA cost data (E.P.A., 1975), and engineering design proposals.
All cost data were adjusted for the Southwestern region as follows:
Total Capital Cost = (BCC) (STP)/177.5 + (LR) (ULC) (100 + SIFJ/100
Where BCC = Base Capital Cost,
STP = Change in the National Average Waste Water Treatment Plant
Cost Index = (1.31)
LR = Land Requirement
ULC = Land Cost ($1,000 per acre)
SIF = Service and Interest Factor (Engineering, contingencies,
and interest during construction = 27 percent).
Operation and maintenance costs were adjusted using a $4.00 per hour
wage rate and the April, 1975, Wholesale Price Index of 169.7 for indus-
trial commodities.
21
-------
STRATEGY
Primary Treatment
XT
Waste Stabilization
Lagoon X2
Activated Sludge
X3
Activated Sludge,
Chemical Addition
X4
Extended Aeration
and Secondary
Clarification XB
Trickling Filter
and Secondary
Sedimentation X6
Coagulation
Filtration Xy
Carbon Sorption
X8
Nitrification and
Dem" trifi cation X9
Ammonia Removal
XI C
Aquaculture
Raceway XT i
Aquaculture
Lagoon Xi 2
1 '2
X
X
Cl
?
X
X
C2
3
x*
-3
4
X
-
X
X
C4
5
X
X
X
C5
67
X
X
X
C6
X
•
X
X
C7
8
X
X
i
X
CB
9
X
X
X
Cg
icr
X
X
X
CIO
11
X
X
X
di
12
X
X
X
X
X
-12
13
X
X
C13
14 15
it
>;
i X
•i
I
i
X
X
C14
X
C15
*Fish grown directly in the waste stabilization
lagoon.
Figure 3. The Cost Matrix Model
22
-------
The STP cost index was adjusted for regional variation as reported in
the Engineering News Record for December, 1975. The EPA complete urban
sewer cost index for 25 U. S. cities, fourth quarter, 1975, was 122.8
and the index for Dallas was 86. Hence, sewer costs in Dallas were
70 percent (86/122.88) of the national average. As a result, all
national capital cost data used in this study are reduced by 30 percent
to adjust prices to the Dallas region. This is assumed to be represen-
tative of construction costs in the Southwest region of the United
States where aquaculture appears to be feasible. In addition, all
such data are expressed in April, 1975 prices.
The two major sources of cost data, A Guide to the Selection of Cost-
Effective Waste Water Treatment Systems and local engineering estimates,
were made compatible by adjusting for local cost differentials. EPA
cost estimates adjusted to the Dallas region were available for all
stages except lagoons. Local lagoon cost estimates were made by the
consulting engineer and a cost index was constructed to show cost dif-
ferences between local costs and the Dallas region costs. For example,
trickling filter costs calculated from local price sources are $537,500
compared to $662,000 from Dallas region EPA sources. Hence EPA regional
cost data are 23 percent higher ($662,000/$537,500 = 1.23) than local
data and all local lagoon costs were increased by 23 percent. Appro-
priate adjustments have been made in all -data to assure comparability
on a regional basis. All cost data presented represents anticipated
costs for the Dallas region.
23
-------
ESTIMATION OF AQUACULTURE PARAMETERS
A major effort was made trying to derive a direct correlation between
the nutrient levels occurring in water and the amount of fish produced
in that water. Several sources dealing directly with primary produc-
tivity were reviewed, but, in every case, the energy levels were either
extremely tentative or based on gross assumptions. Steele (1974)
described the food web of the North Sea and gave figures for yearly
production. However, when referring to the resulting figure, he states,
"In fact, all the values in the figure are so tentative that they must
be considered as an attempt to define problems rather than to provide
answers." This is the general tone of the literature on primary
productivity and ecological modeling.
Allen (1970) describes the widespread use of aquaculture on a world-
wide basis and gives some typical fish production figures. These
figures are for species of fish which are not applicable for use in
this study because of legal or marketing constraints. It should be
noted that water quality is not a major consideration in other coun-
tries. The prime reason for the use of waste water aquaculture in
most of the world is protein production where drastic food shortages
are prevalent.
Coleman, £t al_ (1974) in the Quail Creek Lagoon System considered aqua-
culture as a means to achieve water quality effluent standards. In
this system of six lagoons in series, polyculture experiments conducted
24
-------
produced the only usable water quality data available. Schrouder (1975)
described the effect of aquaculture in waste treatment ponds in Israel,
but only in general terms. He summarized that aquaculture gave a
lagoon system more biological "balance" or stability. The overall result
was higher dissolved oxygen and pH within the lagoon.
Because of the absence of a suitable formula for computing fish produc-
tion from basic measurable water quality parameters, an indirect method
was utilized. Fish farming has been a growing industry in this country
for approximately fifteen years. The industry is profit motivated and
the major effort is directed toward maximizing fish production per
unit of input. For this reason, the majority of fish fanning ponds
are either fertilized or fed to the maximum level possible while main-
taining the water quality necessary to sustain fish life. Of prime
importance is the assurance that dissolved oxygen levels are sufficient
to sustain the fish while maintaining the highest level of fertiliza-
tion and feeding for maximum growth.
Parallel to fish farming goals is the operation of a typical sewage
lagoon. Instead of being fertilized or fed, waste is added in a pre-
dictable amount. Since the most complete oxidation of these waste
products occurs in an aerobic environment it is highly desirable to
maintain dissolved oxygen levels above the minimum life support level
for the food web organisms in the lagoon. In lagoons this is assured
by constructing the lagoon of sufficient size for oxidation at expected
load levels or by providing aeration by mechanical means.
25
-------
Because fish culturists are limited in the amount of fertilizer or
fish feed possible to add to a pond by the size of the pond, there is
a direct correlation between a fish farming pond at maximum productivity
and a sewage lagoon at design capacity. Theoretically, the nutrient
load on the two systems should be roughly the same and the resulting
fish production should be approximately equal. For this project the
assumption was made that average production in fish farms is equal to
the production that could be expected from a properly operated lagoon.
There is a possibility that this assumption would result in higher
productivity than would be realized when water quality is the major goal
of aquaculture, and hence, resulting revenues may be overstated.
However, this assumption may also result in understating the potential
water quality achieved from aquaculture systems.
A review of the literature was conducted of expected production by
species of selected aquaculture products. The cultures selected for
this project are:
Carp Cyprinus carpio
Gold Fish Carassius auratus
Fathead Minnows Pimephales promelas
Golden Shiner Notemigonus crysoleucas
Channel Catfish Ictalurus punctatus
Bigmouth Buffalo Ictiobus bubal as
Polyculture See Table 1
Meyer, et al_ (1967, 1970, 1973) documented the fish farming production
in Arkansas for specific major species of fish listed above. Prather,
et al_ (1954) documented bait fish productipn for g.old fish, fathead
»
26
-------
TABLE 1
TYPICAL POLYCULTURE SYSTEM
Production, Max. Lbs.
Food Habit Per Acre
Plankton feeder
Benthos feeder
Detritus feeder
Specialized types--
Zooplankton
Predator
Insectivores
TOTAL
350
1,375
1,350
470
50
100
3,695
Species
Golden Shiner
Channel Catfish
Gold Fish
Bigmouth Buffalo
Largemouth Bass
Bluegill
minnows, and golden shiners. Altman (1970) summarized national channel
catfish production; Green and Mullins (1959) produced buffalo in rice-
field reservoirs; and Swingle (1957) studied buffalo in the Southeastern
United States. Allen (unpublished manuscript, 1976) documented produc-
tion figures on a world-wide basis primarily for unspecified species
of fish reared in waste water polyculture operations. Specific refer-
ences of fish production are available from Germany, Java, Israel,
Yugoslavia, China, Bengal, and Africa.
The data collected was converted to pounds.of fish per acre and the
production data by species from various literature sources were averaged.
This was than assumed to be the maximum pounds of fish per surface acre
that could be produced on the average in a waste water aquaculture
system. To determine the rate of fish production in the project's
27
-------
sample system (200,000 gal/day) required an additional assumption.
The engineering consultants designed a lagoon system with 3 primary
treatment lagoons and 2 secondary lagoons at 3.4 acres each to treat
the 200,000 gal/day waste water. Experience in lagoon treatment indi-
cates the dissolved oxygen level in a primary lagoon is not stable and
can be expected to be depleted at some time during the summer season.
A secondary lagoon is much more stable and can be used for aquaculture
even though oxygen depletions may'occur. Therefore, assuming an aqua-
culture operation only in the secondary lagoons results in a total of
6.8 surface acres for fish production.
Strategy 1 fish production estimates are therefore based on maximum
fish production expected in an equivalent 6.8 acres of lagoon.
Strategy 2, with the same incoming water quality, could be expected to
produce the same amount of fish. While Strategy 3 should have the same
fish production as Strategies 1 and 2, it must be emphasized that this
could only be achieved under ideal conditions. Danger to fish from
oxygen depletions, heavy metal concentrations, or pesticides is much
greater in a secondary lagoon such as Strategy 3, than in tertiary
lagoons or raceways. In Strategies 4, 5, 6, 7, 8, 9, 13 and 14, fish
production figures are based on the resulting water quality from the
waste treatment stage prior to the aquaculture system. Fish production
is assumed to be a linear function of the parameters of water quality
directly available to the fish. Since phosphorus and nitrogen are not
directly available to the fish until converted into algae or some other
biological organisms, such nutrients do not affect fish production
28
-------
until they become limiting. Sawyer (1944) states that Phosphorus
does not become limiting to algae production until 0.015 mg/1 and
nitrogen does not become limiting until 0.3 mg/1 is reached. In all
strategies these levels are exceeded and therefore the limiting factors
result from the BOD-suspended solids complex. Coleman (personal con-
versation) states that BOD levels below 15 mg/1 are limiting due to
lack of a carbon source and that suspended solids would be limiting to
fish production at less than 20 mg/1. Only in Strategies 8 and 9 do
limitations exist and hence, the computed fish production has been
reduced to 50 per cent of expected production. Expected fish produc-
tions are shown in Table 2.
The Quail Creek study involved a Polyculture system of channel catfish,
golden shiners and Tilapia njlotica stocked into an existing population
of black bullhead, green sunfish, and mosquito fish in a six cell,
serially operated lagoon system. The effluent from each cell was
sampled on a weekly basis and analyzed for the following parameters:
BOD5; Suspended Solids; Volatile Suspended Solids, Total N; Nitrite N;
Nitrate N; Ammonia N; Organic N; Total P, Fecal coliform; Turbidity;
and pH. The Nitrogen forms received special emphasis because of the
project goal of nutrient removal. Ammonia was reduced to less than
1.0 mg/1 after the first cell which left a large portion of Total Nitro-
gen which is composed primarily of organic Nitrogen which is in the
form of algae cells available to fish.
Nutrient removal is a very difficult technique in conventional waste
treatment systems. The removal of Nitrogen and Phosphorus require very
29
-------
CO
o
TABLE 2
ESTIMATED FISH OUTPUT FROM THE VARIOUS AQUACULTURE STRATEGIES*
(Lbs. per surface acre)
Treatment/
Strategy
1
2
3
4
5
6
7
8
9
13
14
Polyculture
3,695
3,695
3,695
1,752
1,695
1,232
1,201
547
521
1,232
1,201
Carp
650
650
650
308
298
217
212
96
91
217
212
Goldfish
1,355
1 ,355
1,355
642
621
452
441
201
192
452
441
Fathead
Minnow
306
306
306
145
140
102
100
45
43
102
100
Golden
Shiner
383
383
383
182
176
128
125
57
54
128
125
Channel
Catfish
1,385
1,385
1,385
657
636
462
450
205
195
462
450
Buffalo
478
478
478
227
220
159
150
71
68
159
155
gals/day flow).
-------
sophisticated and expensive systems. Aquaculture is also ineffective
at nutrient removal unless the nutrients are found in the form of algae
cells or converted to some higher form of aquatic life which may be
utilized by the aquaculture organisms.
Of prime interest in considering aquaculture as an alternative waste
treatment technique is its ability to meet or exceed the water quality
standards issued by the EPA. To determine if this will occur in the
study's sample waste treatment system, the desired parameters were com-
puted on the basis of the removal efficiencies encountered in the Quail
Creek lagoon study. The actual fish production in the reference study
was less than the assumed production and therefore estimates in this
study represent a very conservative waste removal efficiency. Assuming
a linear relationship between rate of removal of pollutants in Quail
Creek and the removal from the sample system the resulting water quality
was computed for the parameters BOD5, Suspended Solids, Total Phosphorus,
Total Nitrogen, and Total Kjeldahl Nitrogen (TKN) and is presented in
Table 5. The Water Quality prior to entering the Aquaculture system
was estimated by the engineering consultant and was based on the EPA
report, A Guide to the Selection of Cost-Effective Waste Water Treatment
Systems (EPA, 1975). The resulting water quality was computed by
parameter according to proper cell effluent in the Quail Creek System.
An additional important consideration in the costs and management of
an aquaculture system is the quantity of stock required each year to
continue the operation. Stocking requirements were estimated on the
basis of the expected outputs in Table 2. Stocking rates are presented
31
-------
in Table 3 for monocultures and in Table 4 for polyculture. All rates
shown are adjusted for a 10 percent mortality rate.
To accurately consider the desirability of utilizing aquaculture in
waste treatment systems requires some knowledge of the effect of this
alternative on resulting water quality. Only one detailed study has
been conducted to determine these values. Coleman, et. al_, (1974)
measured the effect of fish production on water quality in an aquacul-
ture system. Assumptions were made in consultations with Mr. Coleman
to ascertain what levels of waste treatment would correspond with the
various stages of treatment in the Quail Creek Lagoon System. From
these discussions a table of resulting water quality was developed,
by stage and by strategy (Table 5). The data in Table 5 assumes a
linear relationship with water quality data from the Quail Creek Lagoon
System.
It should be emphasized that the output and water quality data presented
is highly tentative and is based on a number of extrapolation assump-
tions. Therefore, these data should be regarded best estimates and
not as absolutes. Data were not obtained from controlled experiments.
It is useful, nonetheless, for comparative purposes and for defining
the potential of aquaculture systems. A number of other factors must
also be considered.
Fish are poikilethermic and therefore highly affected by variation in
temperatures which apply their threshold limits. Thus seasonal varia-
tion in waste water treatment effectiveness will be large. Therefore,
32
-------
TABLE 3
co
ANNUAL STOCKING RATES FOR MONOCULTURES*
(in number of fish)
Strategy
1
o
3
4
5
6
7
8
9
13
14
*Assumes a 10 p
Carpi
3-5" Finger! ing
288 -
(1958r
288
(1958)
288
(1958)
136
(924)
132
(899)
96
(653)
94
(639)
42
(286)
40
(272)
97
(660)
94
(639)
lercent mortality
Goldfish2
333
(2264)
333
(2264)
333
(2264)
222
(1510)
222
(1510)
222
(1510)
222
(1510)
222
(1510)
222
(1510)
222
(1510)
222
(1510)
rate, hence,
Fathead Golden
Minnows2 Shiner2
1111
(7555)
111!
(7555)
1111
(7555)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
rates were
1111
(7555)
1111
(7555)
1111
(7555)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
adjusted by a
Channel Catfish
2-3" Finqerling
15374
(104,543)
15374
(104,543)
15374
(104,543)
7293
(49,592)
7060
(48,008)
4128
(34,870)
4995
(33,966)
2276
(15,477)
2165
(14,722)
51 28
(34,870)
4995
(33,966)
factor of 1.11.
Buffalo
3-5"
2
(1442)
212
(1442)
212
(1442)
01
(687)
(666)
(483)
69
(469), _
31
(211)
30
(204)
(483)
69
(469)
^Grow-out, stock fingerlings
2Spawning operation, stock adults
3First entry indicates number per acre required; number
adjusted for 6.8 acre flow equivalent.
in parentheses is total number required
-------
TABLE 4
U)
4s,
ANNUAL STOCKING RATES FOR POLYCULTURE*
(in number of fish)
Strategy
1
2
3
4
5
6
7
8
9
13
14
Golden Shiner
11,100 .
(75,480)'
11,100
(75,480)
(75,480)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
888
(6038)
Channel Catfish
15,262
(103,782)
15,262
(103,782)
15,262
(103,782)
7293
(45,592)
7060
(48,008)
5128
(34,870)
4995
(33,966)
2276
(15,477)
2165
(14,722)
5128
(34,870)
4995
(33,966)
Goldfish
333
(2264)
333
(2264)
333
(2264)
222
(1510)
222
(1510)
222
(1510)
222
0510)
222
0510]
222
0510)
222
0510)
222
(1510)
Largemouth
Buffalo Bass
209
(1421)
209
(1421)
209
• (1}21)
101
(687) ,
98
(666)
71
(483)
69
(469) •
31
(211)
30
(204)
71
(483)
69
(469)
56
(381)
56
(381)
56
(381)
28
(190)
28
090)
28
(190)
(190)
28
090)
28
090)
28
090)
28
090)
Bluegill
111
(755)
111
(755)
111
(755)
56
(381)
56
(381)
56
(381)
56
(381)
56
(381)
56
(381)
56
(381)
56
(381)
*Assumes a 10 percent morality rate.
First entry indicates number per acre requiredi
adjusted for 6.8 acre flow equivalent.
number in parentheses is total number required
-------
TABLE 5
ABSOLUTE LEVELS OF POLLUTANTS, BY STRATEGY AND STAGE*
Raw
Pollutant Influent
BOD5 mg/1 210
Suspended 230
Solids mgyi
Phosphorus 11
(as P) mg/1
TKN 30
(as N) mg/1
Total N 30
(as N) rng/1
No. 1
Xp
40
95
5
10
11
i
xn
12.5
25.4
1.9
4.9
NO. 2
X2
40
95
5
11
XlP
12.5
25.4
1.3
4.3
3
X2
25.8
70.9
2.96
8.53
NO. 4
XI
140
110
10
30
30
Xfi
30
34
9
29
30
xn
15
19.4
8.1
20
NO. 5
Xl
140
110
10
30
30
Xfi
30
34
5
29
30
Xl?
9.9
22.8
5.3
19
NO.
XI
140
110
10
30
30
X3
20
25
8
29
30
b
xn
10
14.3
7.2
20
NO. 7
Xl
140
no
10
30
30
X3
20
25
8
29
30
XI 2
6.6
16.8
4.7
19
GO
on
*X numbers correspond to Stage numbering in Figure 3.
-------
TABLE 5—Continued
Pollutant
BOD5
Suspended
Solids
Phosphorus
(as P)
TKN
(as N)
Total N
(as N)
No. 8
Xl
140
110
10
30
30
X4
20
20
2
29
30
XI 1
10
11.4
l.£
20
No. 9
XI
140
110
10
30
30
X4
20
20
2
29
30
XI 2
6.6
13.4
1.2
19
No. 10
Xl
140
no
10
30
30
X3
40
35
9
30
30
X9
15
16
9
1
3
No. 11
Xl
140
110
10
30
30
X3
20
25
8
29
30
x?
8
5
0.5
29
30
No. 12
Xl
140
no
10
30
30
X3
20
25
8
29
30
X7
10
5
1
29
30
X8
4
2
0.8
29
30
XH
4
2
0.8
3
3
No. 13
X5
20
25
8
29
30
Xll
10
14.3
7.2
20
No: 14
X5
20
25
8
29
30
Xl?
6.6
16.8
4.7
19
No. 15
x?
40
95
5
10
11
X7
10
5
1
10
11
i
CO
cr>
-------
the effectiveness of aquaculture is approximately 200 days of the year
in Oklahoma.
As in the case of any biological organisms there are many factors which
may disrupt the function of fish in treating waste waters. The param-
eter of prime importance in any waste water system is the maintenance
of dissolved oxygen. Other factors include heavy metals concentration,
pesticides concentration, and the presence of fish disease organisms.
It must be stressed that unlike many waste water treatment systems, a
disrupted aquaculture system requires a long period of time to regain
effectiveness at a considerable expense for restocking. Close super-
vision and monitoring of an aquaculture system is required.
The use of aquaculture increases the effectiveness of lagoons and
therefore requires less land than a lagoon system. However, when com-
pared to physical-chemical techniques, it requires a larger land area.
Very little is currently known on the water quality aspect of aquacul-
ture. It is expected that aquaculture would temper the extremes in
variation which normally occur in oxidation lagoons. Overall a lagoon
treatment system with aquaculture would be slightly more reliable than
one without aquaculture in terms of water quality.
As demonstrated by the Santee Project (California) and a few other
locations, aquaculture may be used to produce sizable recreational
benefits if that is one of the goals. Americans, however, are unaccus-
tomed to the use of waste water in this manner and may therefore
underutilize the potential recreational benefits that occur.
37
-------
A high degree of technical expertise as well as knowledge of fish cul-
turist practices must be available to assure proper operation of an
aquaculture system. However, this level of skill is only needed for a
small portion of the total time of operation, and unskilled labor may
be used the majority of the time. Marketing problems and product
management impose additional managerial skills.
It is highly beneficial to demonstrate that fish are being reared in
a waste water system. This would instill public confidence in the
treatment system. Generally, aquaculture ponds are attractive and
pleasant structures which do not distract from their natural surround-
ings.
Although health considerations relating to aquaculture have not been
intensively studied, the tentative indications are that any additional
retention time in a waste water treatment system as a result of aqua-
culture reduces the presence of human pathogens. The biological
filtering capabilities of fish will also indirectly reduce pathogens.
The concentration bf heavy metals and pesticides in fish which are
grown in waste waters needs study to ascertain if dangerous levels occur.
AQUACULTURE REVENUE CALCULATIONS
Information on potential revenues were derived from reviews of litera-
ture and from direct price quotations received from fish culturists.
Oklahoma Commercial Fishery Statistics for 1974 estimate that Oklahoma
commercial fish growers produced 221,992 pounds of fish, consisting
primarily of catfish (96 percent), with an estimated value of $224,590.
These figures would indicate an average price received by commercial
38
-------
fish growers at $1.02 per pound in 1974 for all production (Oklahoma,
1975).
Estimates of the total poundage of bait fish sold (68 percent wholesale,
32 percent retail), consisting mostly of gizzard shad and river shiner
from state waters and imported from other states, was 393,328 with a
total market value of $659,314. This indicates an average price
received of $1.68 per pound for bait fish in 1974 (Oklahoma, 1974).
Also, in 1974, commercial fishermen harvested 354,198 pounds of rough
fish such as buffalo, carp, freshwater drum, gar, paddlefish, white
bass, and flathead catfish with an estimated value of $63,784.54.
These statistics indicate an average price received of $ .18 per pound.
Prices varied from a low of $ .05 for gar to a high of $ .50 for flat-
head catfish. The retail price of channel catfish, which includes
processing costs plus a regular retail markup, either whole fresh or
frozen was reported at $1.29 per pound in a marketing study in Arkansas
in February, 1973 (Retail, 1975).
The average wholesale price for food size catfish, live weight, in the
Southern region of the United States in 1970 was $ .38 per pound (U. S.
Dept. of Commerce, 1972). Adjusting this price by the Wholesale Price
Index for Farm Products for 1975 prices yields an average price of
$ .63 per pound.
The price for catfish finger!ings in 1970 was reported ranging from
$ .03 to $ .08 each. Assuming catfish of 6" to 8" in length weigh
0.1 pound each in live weight, these figures convert to a price of
39
-------
$ .30 to $ .80 per pound. In terms of 1975 prices adjusted by the
Wholesale Price Index for Farm Products, these figures convert to from
$ .47 to $1.26 per pound for small catfish. Prices paid to commercial
fish growers in the Southern region of the U.S. in 1970 were reported
in the same study to range from $ .35 to $ .40 for food size live weight
catfish. In terms of 1975 prices, these figures adjust to $ .55 to
$ .63 per pound. Processing was reported to add 50 percent to the
value of the product.
Commercial fish prices in Arkansas adjusted by Wholesale Price Index for
Farm Products, are presented in table 6. These prices tend generally
to support the price quotes received in a separate study from 18 licensed
fish growers in Oklahoma, 4 in Texas and 13 in Arkansas. The average
price quotations from these sources are as follows for live bait fish:
Golden Shiner (FOB) $1.70/lb.
Fathead Minnows (FOB) 1.65/lb.
Sunfish (FOB) .85/lb.
Channel Catfish (FOB), food size, live
weight .82/lb.
Catfish (FOB), live weight
6" to 8" 2.50/1b.
Very few price quotations were received for buffalo, carp, largemouth
bass, and bluegill.
Price quotes received from commercial fishermen in Oklahoma, Arkansas,
and Texas, in average price live weight (FOB) were used in this study.
This data is presented in Table 6. It should be noted that these
prices will vary from region to region and by seasonal supply fluctuations.
40
-------
TABLE 6
CURRENT FISH PRICES
($ per Ib.)
Species
Quoted
Prices
Arkansas^
Oklahoma
Price Used
in. Study
Goldfish
$1.75
$1.75
Golden Shiners
1.70
$2.20
$1.68
1.70
Fathead Minnow
Buffalo
1.65
1.32
1.68
.40
.35
1.65
Catfish
6" -8"
Food Size
All Sizes
Carp
2.50
.82
--
__
.79
1.04
.88
2.50
1.02
.17
.20
Bass, Sunfish
Fingerling
Food Size
1.76
.88
Polyculture^ ] .02
^1966 quotations adjusted to 1975 prices.Fred P. Meyer, D. Leroy Gray,
William P. Mathis, J. Mayo Martin, and B. R. Wells, Production and
Returns from the Commercial Production of Fish in Arkansas during 1966.
2
Average price received in Oklahoma for all commercially grown fish in
1974.
41
-------
Live bait prices are particularly susceptible to such forces and are
therefore exceptionally unstable. Good marketing information and fish
brokerage services are currently unavailable.
Estimates of potential revenues from waste water aquaculture systems
were derived using the average quote price column four of Table 6.
Estimated annual production figures (Table 2) supplied by the project's
biologist were multiplied by price estimates to derive the estimated
revenues from an aquaculture system. Table 7 summarizes the potential
revenues from waste water aquaculture systems.
Data in Table 7 indicates that fish from a polyculture system, primarily
sold for bait purposes, is the best revenue producer. Channel catfish
production is second best alternative insofar as gross revenues are
concerned in Strategies 1, 2 or 3. Regional conditions, changing
prices, and other market conditions, of course, could change the gross
revenue estimates. Much more marketing research is needed to determine
potential future market prices, alternative products and innovative
uses of nutrients from waste water treatment systems.
42
-------
TABLE 7
ESTIMATED TOTAL ANNUAL REVENUE FROM AQUACULTURE OUTPUT
lil
-P.
GO
3
4
5
6
7
Strategy
1
2
3
4
5
6
7
8
9
13
14
& .17/lb.
.20/lb.
2.50/lb.
1.75/lb.
1.65/lb.
1.16/lb.
1.02/lb.
Carp1
$ 751
751
751
356
344
251
245
111
105
251
245
Buffalo2
$ 650
650
650
309
299
216
204
97
92
216
211
Channel
Catfish3
$ 23,545
23,545
23,545
11,170
10,813
7,855
7,650
3,485
3,315
7,855
7,650
Goldfish4
$ 16,125
16,125
16,125
7,641
7,390
5,380
5,248
2,392
2,286
5,380
5,248
Fathead
Minnows5
$ 3,434
3,434
3,434
1,627
1.571
1,145
1,122
505
482
1,145
1,122
Golden
Shiner^
$ 4,427
4,427
4,427
2,105
1,389
1,479
1,445
660
624
1,479
1,445
Polyculture?
$ 25,629
25,629
25,629
12,152
11,757
8,547
8,330
3,795
3,614
8,546
8,330
-------
COST DATA AND EVALUATION
SYSTEMS COSTS
The construction* operation and maintenance costs of the fifteen
strategies were compiled using the methodology discussed in the previous
section of this report and are presented in Table 8. Costs are summar-
ized in terms of current costs and discounted annualized streams by
cost category, by stage and by strategy. The total costs are the
present value of all costs associated with treating 200,000 gal/day of
water for a twenty-year period. The discount factor employed was 5-7/8
percent. The costs presented here are not intended to represent exact
projections for specific processes and areas, but rather are intended
to serve as a comparative analysis so that generalized statements
regarding costs and effectiveness of alternative treatment systems can
be made.
Where possible, annual operating costs (0) were further categorized
into operating fixed costs (costs independent of flow) and operating
variable costs (costs dependent upon flow). The (R) cost category
contained in all of the aquaculture systems is negative and represents
the revenues received from the sale of aquaculture output minus the
cost of stock to produce that output. A negative (R) is thus a cash
flow back to the operating institution and serves to reduce the total
costs of water treatment. The (R's) contained in Table 8 are the
highest projections estimated (production and sale of polyculture
output) and must be interpreted as the best possible revenue position
under the assumptions of this analysis.
44
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TABLE 8
PRESENT VALUE OF ESTIMATED COSTS BY CATEGORY, STRATEGY, AND STAGE*
($)
Strategy
Stage
Stage
Strategy
Stage
Stage
Strategy
Stage
Current Costs
1. Waste Stabilization Lagoon
with Aquacul ture Raceway
I (X2)--Waste Stabilization
Pond K = $202,000
0 = 8,500
II (X^)— Aquacul ture K= 111,930
Raceway 0 = 5,877
R = -20,749
2. Waste Stabilization Lagoon
with Aquacul ture Lagoon
I (X2)— Waste Stabilization
Pond K = 202,000
0 = 8,500
II (X12)— Aquacul ture K = 42,500
Lagoon 0 = 7,373
R = 20,749
_3. Waste Stabilization Lagoon
with Fish
I (X2)- -Waste Stabilization
Pond K = 202,000
0 = 8,500
--Aquacul ture K= None
Lagoon in X2 0 = 7,373
R = 20,749
*K = Capital Costs, 0 = Annual Operating (v =
and R = net revenues from a polyculture aquacul
Discounted**
Annual i zed Stream
$202,000
98,515
111,930
68,114
-240,481
TOTAL
202,000
98,515
42,500
85,453
-240,481
TOTAL
202,000
98,515
85,453
.-240,481
TOTAL
variable, f =
ture system.
$300,515
-60,437
$240,078
300,515
-112,528
$187,987
300,515
-155,028
$145,487
fixed),
**Discount base of 5-7/8 percent
45
-------
TABLE 8—Continued
Current Costs
Strategy 4. Trickling Filter with
Aquaculture Raceway
Stage I (XT)— Primary K =
Treatment Of =
v =
Stage II Us)— Trickling Filter K =
& Secondary Of =
Sedimentation v =
Stage III (X]])— Aquaculture K =
Raceway 0 =
R =
Strategy 5. Trickling Filter with
Aquaculture Lagoon
Stage I (X])--Primary K =
Treatment Of =
v =
Stage II (XeJ—Trickling Filter K =
& Secondary Of =
Sedimentation v =
Stage III (X]2)— Aquaculture K =
Lagoon 0 =
R =
Strategy 6. Activated Sludge with
Aquaculture Raceway
Stage I (X-|)— Primary K =
Treatment Of =
v =
Stage II (Xa) —Activated K =
Sludge Of =
v =
Stage III (X-j-|) --Aquaculture K =
Raceway 0 =
R =
$293,800
7,630
1,937
398,200
6,629
6,202
111,930
5,877
-10,616
293,800
7,630
1,937
398,200
6,629
6,202
42,500
7,373
10,150
274,600
7,630
1,729
568,800
11,211
4,931
111,930
5,877
7,342
Di
scounted
Annual i zed Stream
$293,800
88,431
22,452
398,200
72,664
71 ,866
111,930
68,114
-123,039
TOTAL
293,800
88,431
22,452
398,200
72,664
71,866
42,500
85,453
-117,639
TOTAL
274,600
88,431
20,040
568,800
129,933
57,156
111,930
68,114
-85,094
TOTAL
$404,683
542,730
57,005
$1,004,418
404,683
542,730
10,314
$957 ,727
383,071
755,889
94,950
$1,233,910
46
-------
TABLE 8—Continued
Current Costs
Strategy
Stage
Stage
Stage
Strategy
Discounted
Annual i zed Stream
7.- Activated Sludge with
Aquaculture Lagoon
I (X]) --Primary
Treatment
II (X3)— Activated
Sludge
III (XI 2)— Aquaculture
Lagoon
K =
Of =
v =
K =
Of =
v =
K =
0 =
R =
$274,600
7,630
1,729
568,800
11,211
4,931
42,500
7,373
-7,151
$274,600
88,431
20,040
568,800
129,933
57,156
42,500
85,453
-82,880
TOTAL
$383,071
755,889
45,073
$1,184,033
8. Activated Sludge—Chemical Addition
with Aquaculture Raceway
Stage I (Xi)—Primary
Treatment
K = 249,560
Of = 6,354
v = 1,504
Stage II (XA)—Activated Sludge K = 629,440
with Chemical Of = 11,925
Addition v = 5,174
Stage III (X-|-|)—Aquaculture
Raceway
K = 111,930
0 = 5,877
R = -3,185
249,560
73,647
17,426 340,633
629,440
138,212
59,971 827,623
111,930
68,114
-36,914 143,130
TOTAL $1,311.386
Strategy 9. Activated Sludge—Chemical Addition
with Aquaculture Lagoon
Stage I (X])—Primary
Treatment
K = 249,560
Of = 6,354
v = 1,504
Stage II
— Activated Sludge K
with Chemical Of
Addition v
Stage III (X]2)--Aquaculture
Lagoon
K
0
R
629,440
11,925
5,174
42,500
7,373
3,004
249,560
73,647
17,426
629,440
138,212
59,971
42,500
85,453
-34,816
340,633
827,623
93,137
TOTAL $1.261,393
47
-------
TABLE 8—Continued
Current Costs
Discounted
Annuali zed Stream
Strategy 10. Activated Sludge with
Stage
Stage
Stage
Strategy
Stage
Stage
Stage
Strategy
Stage
Stage
Stage
Denitrification System
I (XT)— Primary K = $281 ,000 $281,000
Treatment Of = 7,222 83,700
v = 1,798 20,844
II (X3 )— Activated K= 471,000 471,000
Sludge Of = 9,561 110,809
v = 4,900 56,796
III (Xg)— Nitrification & K = " 515,000 515,000
Denitrification Of= 15,367 178,104
v = 3,629 42,060
TOTAL
11. Activated Sludge
with
Coagulation Filtration
I (XT)— Primary K
Treatment Of
v
II (X3 )— Activated K
Sludge Of
v
III (Xy)— Coagulation K
Filtration Of
v
12. Activated Sludge
Ammonia Removal
I (X^-Primary
Treatment
II (X3)— Activated
Sludge
III (Xy)— Coagulation
Filtration
System
= 274,600
7,018
1,729
= 652,800
= 16,211
6,631
= 753,000
= 19,710
= 10,950
with Carbon Sorption,
System
K = 274,600
Of = 7,018
v = 1 ,729
K = 652,800
Of = 16,211
v = 6,631
K = 677,000
Of = 19,710
v = 10,950
274,600
81 ,334
20,040
652,800
187,882
76,859
753,000
228,439
126,911
TOTAL
>
274,600
81 ,334
20,040
652,800
187,882
76,859
677,000
228,439
126,911
$385,544
638,605
735,164
$1,759,313
375,974
917,541
1,108,350
$2,401,865
375,974
917,541
1,032,350
48
-------
TABLE 8—Continued
Current Costs
Strategy 12— Continued
Stage IV (Xs) —Carbon Sorption K =
0 =
Stage V (Xio)— Ammonia Removal K =
Of =
v =
Strategy 13. Extended Aeration with
Aquaculture Raceway
Stage I (Xs)— Extended Aeration K =
and Secondary Of =
Clarification v =
Stage II (X-|-| )— Aquaculture K =
Raceway 0 =
R =
Strategy 14. Extended Aeration with
Aquaculture Lagoon
Stage I (X5)— Extended Aeration K =
and Secondary Of =
Clarification v =
Stage II (Xi 2)— Aquaculture K =
Lagoon 0 =
R =
$753,000
730
25,000
13,870
3,650
516,000
9,417
4,898
111,930
5,877
7,347
516,000
9,417
4,898
42,500
7,373
-7,153
Discounted
Annual i zed Stream
$753,000
8,461
25,000
160,753
42,304
TOTAL
516,000
109,143
56,764
111,930
68,114
-85,082
TOTAL
516,000
109,143
56,764
42,500
85,453
-82,903
TOTAL
$761,461
228,057
$3,315,383
681 ,907
94,962
$776,869
681 ,907
45,050
$726,957
Strategy 15. Waste Stabilization Lagoon with
Coagulation Filtration
Stage I (X2)— Waste Stabilize- K =
tion Pond 0 =
202,000
8,600
202,000
99,674
301 ,674
Stage II (Xj)—Coagulation
Filtration
K = 753,000
Of = 20,284
v = 12,010
753,000
235,093
139,194 1.127,287
TOTAL $1,428,961
49
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While the costs of conventional stages and strategies are largely
self-explanatory, the derivation of aquaculture costs requires some
explanation. Three types of aquaculture physical plants were selected
and costs allocated accordingly. The first is a three cell aquaculture
raceway (X]-j) designed primarily to facilitate fish handling, the second
(X-J2) is a single fish lagoon system to be built as an additional stage
of a conventional system. Strategy 3 requires no new construction but
is simply a grow-out or fish spawning operation directly in a secondary
oxidation wastewater lagoon. All three systems have different costs
because of varying physical and operational characteristics. In all
three the resulting net revenues are species dependent. That is, they
reflect varying prices anticipated from the sale of the product.
The estimated operating costs for both lagoon and raceway aquaculture
systems are presented in Table 9. The higher operating costs for
lagoons is attributable primarily to the increased difficulty of fish
handling procedures during harvest, and to additional disease treatment
costs because of the larger surface area. While the need for disease
treatment is a variable for actual operations, the assumption here is
that, on the average, a chemical disease treatment will be required
once a year and is therefore included as an annual operating cost.
The cost of stock by species for each strategy is presented in Table 10,
and Table 11 shows the cost of stock, by species, for a polyculture
system. The polyculture column in Table 10 is the total column from
Table 11. It is evident that the cost of stocking is an extremely
variable element, ranging from a low of $11 for bigmouth buffalo in
50
-------
TABLE 9
ESTIMATED AQUACULTURE OPERATING COSTS EXCLUDING STOCK
Expenditure Category Raceway Lagoon
General--
Fish Culturist, 1/4 time including
disease analysis $3,000 $3,000
Laborer, daily care, including
D.O. and pH analysis 1
Disease Treatment
Vehicle, $ .10/mile @ 1,000 miles/yr.
Materials and Supplies
(screws, land tools, buckets, etc.)
Subtotal*
Stocking, excluding species
Transporting, 100 miles @ .50/mi.
Laborer, 1 man/day
Prophylactic Disease Treatment
Subtotal
Harvesting
Seines1
Miscellaneous Supplies
Disease Chemicals
Labor2
Vehicle, @ .20/mi..
Subtotal
TOTAL
,584
440
200
150
$5,374
50
24
25
$ 99
100
100
50
144
10 •
$ 404
$5,877
1,584
1,320
200
150
50
24
25
250
100
50
600
20
$6,254
$ 99
$1 ,020
$7,373
^2100' seines for raceway and 1500 seine for lagoon, amortized for
three years.
26 man/days of labor for raceway, 25 man/days for lagoon, both exclude
fish culturist accounted for in general category.
51
-------
en
ro
TABLE 10
ESTIMATED COST OF STOCK FOR MONOCULTURE BY STRATEGY AND SPECIES
Strategy
1
2
3
4
5
6
7
8
9
13
H
Carp1
$98
98
98
46
45
33
32
14
14
33
32
Buffalo2
$72
72
72
34
33
24
23
11
10
24
23
Channel
Catfish3
$3,135
3,135
3,135
1,488
1,440
1,047
1,020
465
441
1,047
1,020
Goldfish4
$396
396
396
264
264
264
264
264
264
264
264
Fathead
Minnows 5
$125
125
125
100
100
100
100
100
100
100
100
Golden.
Shiner6
$129
129
129
103
103
103
103
103
103
103
103
Polyculture?
$4,880
4,880
4,880
1,536
1,607
1,205
1,179
610
585
1,205
1,177
13-5" Carp Fingerling, $ .05 each, 10/lb., $ .50/lb.
23-5" Buffalo Fingerling, $.05 each, 10/lb., .50/lb.
33" Catfish Fingerling, $.03 each, 1000/lb., $30.00/lb.
4Adult Fish, $1.75/lb.
5Adult Fish, $1.65/lb.
6Adult Fish, $1.70/lb.
?Total stocking cost for all species, see Table 11.
-------
CJl
TABLE 11
ESTIMATED COST OF STOCK FOR POLYCULTURE BY STRATEGY AND SPECIES*
Strategy
1
2
3
4
5
6
7
8
9
10
11
Golden
Shiner1
$1 ,283
1,283
1 ,283
103
103
103
103
103
103
103
103
Channel
Catfish2
$3,114
3,114
3,114
1,368
1,440
1,047
1,020
465
441
1,047
1,020
Goldfish3
$396
396
396
26
26
26
26
26
26
26
26
Buffalo4
$71
71
71
34
33
24
25
11
10
24
23
Largemouth
Bass5
$8
8
8
1
1
1
1
1
1
1
1
Bluegill6
$8
8
8
4
4
4
4
4
4
4
4
Total
$4,880
4,880
4,880
1,536
1,607
1,205
1,179
610
585
1,205
1,177
lAdult Fish, $1.70/lb.
23" Finger-lings, 3* each, 1000/1 b., $30.00/lb.
3Adult Fish, $1.75/lb.
43-5" Fingerlings, 5$ each, 10/lb., $ .50/lb.
52" Fingerlings, 2
-------
Strategy 8 to a high of $4,880 for Polyculture stock in Strategies 1,
2, and 3. Stocking costs were derived from the stocking rates in
Tables 3 and 4, which are based on the projected outputs. In estimating
the Polyculture stock costs the assumption was made that small quanti-
ties of some species, i.e. bass and bluegill, could be purchased at the
prices specified in the footnotes at the bottom of Table 10. To the
extent that this assumption might not hold, the figures presented may
underestimate the cost of stocking.
*
Table 12 presents the estimated annual net revenues from the sale of
aquaculture output. Net revenues are the estimated revenues in the
previous section, Table 7,.minus the cost of stock from Table 10. Net
revenues from Polyculture exceed those from all other species for
every strategy. The monoculture with the highest net revenue is channel
catfish. Hence, from the aspect of net revenue generation, a Polycul-
ture system contributes more to an overall cost reduction for treatment
systems than does any of the single systems. However, since catfish
are fairly close in forms of revenue generating ability, and since cat-
fish markets are the most hiohly developed as are the techniques
associated with their production, it is reasonable to consider catfish
as a viable species with excellent potential for use in an aquaculture
system. However, the biota which develops in the typical wastewater
system is not suitable for the production of channel catfish to a size
larger than 6"-8", and the market for this size fish may be limited.
Table 13 summarizes the annual net revenues for both Polyculture and
catfish production and lists present value of the discounted income
streams for a 20-year period. These are the (R) values contained in
54
-------
tn
en
TABLE 12
ESTIMATED ANNUAL NET REVENUES FROM AQUACULTURE
(Revenue minus cost of stock)
Strategy
1
2
3
4
5
6
7
8
9
13
14
Carp
$653
653
653
310
299
218
213
97
91
218
213
Buffalo
$578
578
578
275
266
192
181
86
82
192
188
Channel
Catfish
$20,410
20,410
20,410
9,682
9,373
6,808
6,630
3,020
2,874
6,808
6,630
Goldfish
$15,729
15,729
15,729
7,377
7,126
5,116
4,984
2,128
2,022
5,116
4,984
Fathead
Mi nnows
$3,309
3,309
3,309
1,527
1,471
1,045
1,022
405
382
1,045
1,022
Golden
Shiner
$4,298
4,298
4,298
2,002
1,286
1,376
1,342
557
521
1,376
1,342
Polyculture
$20,749
20,749
20,749
10,616
10,150
7,342
7,151
3,185
3,004
7,341
7,153
-------
TABLE 13
DISCOUNTED VALUES FOR ANNUALIZED STREAM OF NET REVENUES BY STRATEGY
FOR SPECIES YIELDING THE HIGHEST NET REVENUES*
Strategy
1
2
3
4
5
6
7
8
9
13
14
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
Catfish
Polyculture
Catfish
Polyculture
Catfish
Polyculture
Catfish
Polycul ture
Catfish
Polyculture
Catfish
Polyculture
Catfish
Polyculture
Catf i sh
Polyculture
Catfish
Polyculture
Catfish
Polyculture
Catfish
Polyculture
Annual Net Revenues
$20,410
20,410
20,410
9,682
9,373
6,808
6,630
3,020
2,874
6,808
6,630
$20,749
20,749
20,749
10,616
10,150
7,342
7,151
3,185
3,004
7,347
7,153
20-Year
Discounted Stream
$236,552
236,552
236,552
112,214
108,633
78,905
76,842
35,002
33,310
78,905
76,842
$240,481
240,481
240,481
123,039
117,639
85,094
82,880
36,914
34,816
85,082
82,903
*In all cases, the system yielding the highest net revenue is the
polyculture system followed by a monoculture of channel catfish.
These are the only systems shown since, under the assumptions of this
study, these are the only economical alternatives. To calculate the
discounted stream for other species, multiply the net revenues from
Table 12 by a factor of 11.59.
56
-------
the cost summaries in Table 8. For these two cultures the revenues
generated are highly significant and reduce substantially the costs of
treatment construction and operation.
Caution is necessary in applying the aquaculture cost and revenue data
presented. All such data were estimated from the biological parameters
and revenue parameters presented in the section on aquaculture. All of
the data deficiencies discussed in those sections apply to the data
presented here. The very tentative nature of the estimated production
capabilities of aquaculture makes the aquaculture revenue data tenta-
tive, and hence, must be used as a first estimate of the probable
magnitude of the economic viability of these systems for wastewater
treatment. In addition, water quality parameters have not been firmly
established for aquaculture systems by good, scientifically controlled
experiments.
There are certain factors in selecting water treatment strategies that
are not quantifiable in monetary terms, but are still of great impor-
tance in any decision-making process. Quantitative data compiled with
qualitative considerations will delineate the alternatives more fully.
These non-monetary factors were compiled by the project's consulting
engineer in consultation with the biologist. Seven non-monetary cost
factors were considered of importance, and each was ranked on a scale
of one to ten, from minimum to maximum impact. The factors considered
were 1) land requirements, 2) susceptibility to climatic variations,
3) effect on the system of industrial pollutants, 4) reliability of the
57
-------
process, 5) ease of operation and maintenance, 6) air pollution gen-
erated, and 7) waste pollutant by-products. Table 14 presents the
ranking of these non-monetary considerations.
COST-EFFECTIVE SYSTEMS
In the analysis of cost-effective strategies, multiple objective levels
defining alternative water quality parameters were established. The
first objective level is stated in terms of declining levels of five
day biochemical Oxygen demand (6005) and Suspended Solids (SS). The
second objective level is defined in terms of declining levels of nutrients
in the form of Phosphorus (P) and TKN Nitrogen. The multiple objective
level approach was deemed desirable because current secondary treatment
standards are defined in terms of BODs and SS without reference to
nutrient levels. Currently, waste water treatment systems are meeting
secondary standards when BODs £30 mg/1, and SS 130 mg/1. The assump-
tion is made that future standards for advanced treatment systems will,
in part, be defined with respect to P and N levels. For the various
strategies under consideration there is not a single coefficient for
all pollutant reduction. Some stages of the treatment strategies
influence levels of a given pollutant but does not reduce others. As a
result, the multiple objective level approach was adopted.
Table 15 presents the most cost-effective aquaculture system and con-
ventional system (or stage) for achieving objectives A through F in
BODs and Suspended Solids reduction. In addition, the total discounted
costs of operating the system are presented, and the cost of the aqua-
culture system (where applicable) is expressed as a percentage of the
cost of the conventional system.
58
-------
tn
vo
TABLE 14
NON-MONETARY FACTORS ASSOCIATED WITH EACH STAGE
Stage
Xl
X2
X3
X4
X5
X6
X7
Land
Requirement
1
10
5
6
5
5
2
Climatic
Variation
2
9
1
1
1
4
1
Effects of
Industrial
Pollutants
1
10
3
3
3
3
1
Reliability
of Process
1
2
2
2
1
4
1
Ease of
Operation &
Maintenance
3
2
6
3
5
5
6
Air
Pollution
Generated
2
1
1
1
1
6
1
Waste
. Pollutant
By-Products
10
1
4
5
2
3
4
X8
Xg
10
6
4
2
10
3
3
Xio
xn
10
8
6
10
6
1
1
XI 2
X13
XI 4
X15
Ranked on a scale of 1 to 10, from minimum to maximum.
-------
TABLE 15
COST EFFECTIVE SYSTEMS TO ACHIEVE ALTERNATIVE OBJECTIVE LEVELS
OF BOD5 AND SUSPENDED SOLIDS (SS)
Alternative Objectives* Aquaculture
Cost, Aquaculture
% of Conventional
Conventional
Objective A
BQD5 1 30, SS 1 30
Strategy 2
$187,987
28%
X5
Ext.Aeration
$681,907
Objective B Strategy 2
BODSl 25, SSI 26.25 $187,987
28%
X5
Ext.Aeration
$681,907
Objective C
BOD5 1 20, SS 1 22.5
Strategy 14
$726,957
62%
X4 Act.Sludge
Chemical Add.
$1,168,256
Objective D
BODSl 15, SS 118.75
Strategy 14
$726,957
52%
X7 Coagula-
tion Filtra.
$1.396,750
Objective E
BODsl 10, SSI 15
Strategy 13
$783,046
56%
Coagula-
tion Filtra.
$1,396,750
Objective F
BOD5 1 5, SS 1 7
None
X8
Carb. Sorp.
$3,087,326
*mg/l.
60
-------
The most cost-effective system to meet objective A (current secondary
treatment standards) is Strategy 2, a Waste Stabilization Lagoon with
an Aquaculture lagoon. Costs for the Strategy 2 Aquaculture system are
only 28 percent of the costs of achieving that level of water quality
by the most cost-effective conventional system (extended aeration)
although both these systems also meet objective B.
In all cases, when an aquaculture system is capable of achieving a
given BODs and SS objective, the aquaculture strategy is the most cost-
effective. Not only is the aquaculture the most cost-effective, but
in every case the cost differential between the aquaculture strategy
and the conventional strategy is substantial. The minimum savings
associated with aquaculture are found for objective C, where aquaculture
costs are 62 percent of conventional costs, and the maximum cost saving
is achieved for objectives A and B (28 percent of conventional costs).
Under the assumptions of this study there is no aquaculture system that
can achieve objective F. However, theoretically aquaculture systems
should be able to reduce all plant nutrients and this limitation of
aquaculture probably reflects the methodology of this study plus the
lack of knowledge with respect to removal efficiency. Data is unavail-
able to substantiate this capability of aquaculture. Only stage four
(Xg) of the conventional strategy 12 can reduce BOD5 and SS to such
low levels, and then only at a staggering cost of more than three
million dollars. This, of course, indicates that the potential savings
from aquaculture might be massive if future research shows that aqua-
culture can, in fact, reduce BOD and SS to the levels defined in
objective F.
61
-------
A similar cost-effective ranking of strategies is obtained when the
Phosphorus/TKN objectives are employed. These comparisons are presented
in Table 16. Strategy 2, a Waste Stabilization Lagoon with an Aquacul-
ture Lagoon is the most cost-effective strategy for all objectives with
the exception of D. Again, data on water quality are insufficient to
allow an exact determination of TKN values and therefore it is currently
unknown, using the methodology employed in this study, whether or not
any of the alternative aquaculture systems will meet a TKN <_ 3.
Strategy 2 will reduce P to 1.3 mg/1 and will thus meet the requirements
of objective D, but must be rejected as a result of the TKN unknown (see
Table 5). The only strategy that meets those stringent levels of
nutrient removal is strategy 12 at a cost of $3,315,383.
The cost saving associated with the use of aquaculture relative to con-
ventional methods for nutrient reduction are even more significant than
for BOD/suspended solids reduction. For objectives B and C, the cost
of aquaculture represents only 6 percent of the cost of achieving that
level of nutrient reduction using the most cost-effective conventional
system. This differential is striking and indicates the potential of
aquaculture for low cost nutrient reduction.
For objective A a Stabilization Lagoon with an Aquaculture Lagoon is
more cost-effective than simply the Stabilization Lagoon by itself.
This outcome is obtained because the Aquaculture Lagoon generates
enough revenue to recoop part of the costs of building and operating
the Stabilization Lagoon. This cost-effective ranking is therefore
dependent upon the revenues received from the sale of aquaculture products,
62
-------
TABLE 16
COST EFFECTIVE SYSTEMS TO ACHIEVE ALTERNATIVE
OBJECTIVE LEVELS OF PHOSPHORUS AND TKN*
Alternative Objectives**
Objective A
PI 9, TKN 113
Objective B
P 17, TKN 19
Objective C
P 1 5, TKN 15
Objective D
P 13, TKN 13
Aquaculture
Strategy 2
$187,987
Strategy 2
$187,987
Strategy 2
$187,987
None
Cost, Aquaculture
% of Conventional
62%
6%
6%"
Conventional
Xz Waste Sta-
bilization L,
$300,515
Strategy 12
$3,315,383
Strategy 12
$3,315,383
Strategy 12
$3,315,383
*TKN values for aquaculture are unknown, but always assumed to be less
than Total N values which are known.
**mg/l.
63
-------
It is useful to note that the least expensive system (strategy 3,
where fish are grown directly in the Stabilization Lagoon) is rejected
for all objectives because of high suspended solids (SS = 70.9) which
fail to meet current secondary treatment standards. In addition, it
is felt that this strategy is extremely susceptible to biological
disruption, especially oxygen depletion, and is therefore not capable
of providing a reliable treatment process.
The most cost-effective alternative becomes much less clear when the
BOD/suspended solids objectives are combined with the P/TKN objectives.
Through personal conversations with Mr. Coleman, Assistant Deputy Commis-
sioner for Environmental Health Services, Oklahoma State Department of
Health, a perspective tertiary treatment level was set up. This level
was defined at BOD5 1 10, Suspended Solids 1 15, Phosphorus 1 5, and
TKN £ 5. Table 17 presents a classification of effluent quality by
stage and strategy with respect to primary, secondary, and tertiary
treatment levels. A (Y) indicates that the minimum pollutant level
requirement is met or exceeded, and an (X) indicates that the particular
pollutant is greater than defined by the standard and is therefore a
limiting factor and prevents achievement of that standard.
All strategies, with the exception of strategy 3, meet secondary stan-
dards with strategy 2 as the most cost-effective. Tertiary treatment
levels, on the other hand, are only met by strategy 12, and perhaps by
strategies 8 and, 9, although an exact estimate of TKN is unavailable
for the aquaculture stages. This is not an insignificant factor,
however, since the costs for the conventional strategy 12 ($3,315,383)
64
-------
TABLE 17
CLASSIFICATION AND ANALYSIS OF EFFLUENT QUALITY
Strategy
No. 1
Stage
Stage
No. 2
Stage
Stage
No. 3
Stage
No. 4
Stage
Stage
Stage
No. 5
Stage
Stage
Stage
No. 6
Stage
Stage
Stage
No. 7
Stage
Stage
Stage
I
II
I
II
I
I
II
III
I .
II
III
I
II
III
I
II
III
(X2)
(XI 1)
(X2)
(Xi?)
(X2)
(XI J
(X6
(Xn)
(XT)
(X6)
(Xi?
(XT)
(X3
(Xn)
(XT)
(X3)
(Xij»)
BOD51
X
Y
X
Y
Y
X
Y
Y
X
Y
Y
X
Y
Y
X
Y
Y
Secondary
30 SSI 30
X
Y
X
Y
X
X
X
Y
X
X
Y
X
Y
Y
X
Y
Y
Treatment
P
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
TKN
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Total N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
BOD51
X
X
X
X
X
X
X
X
X
X
X
X
X
Y
X
X
Y
Tertiary
10 SS11
X
X
X
X
X
X
X
X
X
X
X
X
X
Y
X
X
X
Treatment
5 P£5
Y
Y
Y
Y
Y
X
X
X
X
X
X
X
X
X
X
X
Y
TKN 15*
X
Y
X
Y
X
X
X
X
X
X
X
X
X
X .
X
X
X
en
X = Limiting Factor Y = Non-Limiting Factor
*TKN considered non-limiting only when Total N = the TKN requirement
-------
TABLE 17--Continued
Strategy
No. 8
Stage
Stage
Stage
No. $
Stage
Stage
Stage
No. 10
Stage
Stage
Stage
No. 11
Stage
Stage
Stage
No. 12
Stage
Stage
Stage
Stage
Stage
No. 13
Stage
Stage
No. H
Stage
Stage
No. 15
Stage
Stage
I
II
II
I I
II 1
III
I 1
II 1
III
I (
II (
III
XT)
X4)
Xn)
;xij
!x4)
(X12
;xi)
;x3)
tX9)
Xl)
X3)
(X7)
I (Xl)
n (x3)
HI (X7)
iv (XB)
V (Xin)
I (X5)
II (Xii)
I (X5)
II (Xl?)
I (X2)
II (Xy)
Secondary
BODsl 30 SS 130
X
Y
Y
X
Y
Y
X
X
Y
X
Y
Y
X
Y
Y
Y
Y
Y
Y
Y
Y
X
Y
X
Y
Y
X
Y
Y
X
X
Y
X
Y
Y
X
Y
Y
Y
Y
Y
Y
Y
Y
X
Y
Treatment
P
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
I'KN
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Total N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
BODR^-
X
X
Y
X
X
Y
X
X
X
X
X
Y
X
X
Y'
Y
Y
X
Y
X
Y
X
Y
Tertiary
10 SS11
X
X
Y
X
X
Y
X
X
X
X
X
Y
X
X
Y
Y
Y
X
Y
X
X
X
Y
Treatment
5 P<5
X
Y
Y
Y
Y
Y
X
X
X
X
X
Y
X
X
Y
Y
Y
X
X
X
Y
Y
Y
TKN < 5*'
X
X
X
X
X
X
X
X
Y
X
X
X
X
X
X
X
Y
X
X
X
X
X
X
01
CTl
-------
are more than double the costs of the aquaculture strategies 8 and 9
($1,311,386 and $1,261,393 respectively). Again, substantiation of
removal efficiencies for aquaculture systems is critical for ascertain-
ing the most cost-effective strategy. Because of this lack of knowledge
strategies 8 and 9 must be currently rejected as alternatives to achieve
tertiary treatment levels. Thus, strategy 12, an activated sludge
plant with coagulation filtration, carbon sorption, and ammonia removal
is the only strategy capable of meeting the tertiary definition and
hence is cost-effective.
Unfortunately, the most cost-effective systems for nutrient removal
(strategies 2 and 1) are limited in BODs and Suspended Solids reduction.
The latter is reduced to 25.4 mg/1 and the former to 12.5 mg/l~both
above the levels required for tertiary classification. This "trade-
off" problem between the BOD/Suspended Solids complex and the nutrient
complex is typical of the water quality analysis of the various strat-
egies examined in this study. The most cost-effective system for a
particular municipality will therefore be a function of both the com-
position of influent and the nature of the receiving waters. Where
the major problem area is associated with nutrients, the Stabilization
Lagoon with an aquaculture system is by far the most efficient system.
When the major area of concern is with BOD/suspended solids more
advanced mechanical/aquaculture strategies are most cost-effective
(i.e., strategy 13), even though these systems are less efficient at
nutrient reduction.
The reason strategies 1 and 2 are so efficient at nutrient reduction,
relative to the more advanced aquaculture systems, is that the
67
-------
Stabilization Lagoon itself reduces P by 55 percent and TKN by 67
percent before the effluent enters the fish lagoon or raceway. In con-
trast, the nutrient levels in the effluent entering the aquaculture
stages in the more advanced systems is still very high. Therefore,
since the aquaculture stages of the more advanced strategies have more
nutrients to remove the overall nutrient reduction by those strategies
tends to be less than that achieved in strategies 1 and 2.
Table 18 shows the efficiency of the various strategies in terms of
the percentage reduction for the five types of pollutants. The per-
centage reduction figures allow for a comparison among strategies as to
cost vs. efficiency. Table 19 ranks the strategies with respect to
total costs, by stage.
Throughout this report it has been emphasized that much of the aqua-
culture data is tentative in nature and is, of course, dependent upon
the assumptions made. As a result, even though it is felt that all of
the assumptions made result in conservative estimates, the possibility
exists that the estimates bias the cost-effectiveness outcome in favor
of aquaculture—especially given the very large cost differences
relative to conventional systems presented in Table 15 and Table 16.
Since those cost estimates are made on the basis of the "most optimis-
tic" net revenues generated (polyculture systems), estimates should
also be made on the basis of the "most pessimistic" possible net
revenues generated. These estimates are presented in the second cost
column of Table 19.
68
-------
TABLE 18
CUMULATIVE PERCENT REDUCTION OF POLLUTANTS, BY STRATEGY AND STAGE*
Pollutant
BOD5
Suspended Solids
Phosphorus (as P)
TKN (as N)
Total N (as N)
No. 1
x?
81
59
55
67
63
Xll
94
88
83
84
*Assumes raw influent of BOD5 = 2
total phosphorus (as P) = 11 mg/
Total N (as N) = 30 mg/1.
No. 2
x?
81
59
55
67 ;
63
'
Xl?
94
88
88
86
'No. 3
X2
88
69
73
71
0 mg/1, suspend
1, TKN (as N) =
No. 4
Xl
33
52
9
0
0
Xfi
86
85
18
3
0
xn
93
92
27
33
i
No. 5
Xl
33
52
9
0
0
Xfi
86
85
18
3
0
Xl?
95
90
52
37
No. 6
Xl
33
52
9
0
0
K
90
89
27
3
0
Xll
95
94
35
33
ed solids = 230 mg/1 ,
30 mg/1 , and
No. 7
Xl
33
52
9
0
0
X?
90
89
27
0
XI?
97
93
57
37
CTt
VD
-------
TABLE IS—Continued
Pollutant
BOD5
Suspended
Solids
Phosphorus
(as P)
TKN
(as N)
Total N
(as N)
XT
33
52
9
0
0
No.
X4
90
91
82
3
0
8
Xll
95
95
84
33
XT
33
52
9
0
0
No.
X4
90
91
82
0
y
Xl?
97
94
89
37
Xl
33
52
9
0
O1
No.
x^
81
85
18
0
0
10
X9
93
93
27
97
90
Xl
33
52
9
0
0
No.
XT
90
89
27
3
0
11
x?
96
98
95
3
0
Xl
33
52
9
0
0
N
X3
90
89
27
3
0
0. 1
XT
95
98
90
3
0
2
XH
98
99
93
3
0
*10
98
99
93
93
90
No.
XS
90
89
27
0
0
13
Xll
95
94
35
33
No.
X">
90
89
27
0
0
14
Xl?
97
93
57
37
No.
X?
81
59
55
67
63
15
X7
95
98
91
67
63
-------
TABLE 19
RANK ORDER OF STRATEGIES BY CUMULATIVE COSTS AND STAGES
3
2
1
14
13
5
4
7
6
Strategy
Waste Stabilization Lagoon
with Fish
Waste Stabilization Lagoon
with Aquaculture Lagoon
Waste Stabilization Lagoon
with Aquaculture Raceway
Extended Aeration with
Aquaculture Lagoon
Extended Aeration with
Aquaculture Raceway
Trickling Filter with
Aquacirlture Lagoon
Trickling Filter with
Aquaculture Raceway
Activated Sludge with
Aquaculture Lagoon
Activated Sludge with
Aquaculture Raceway
X2
X2
XI 2
X2
X5
XI 2
XB
Xll
Xl
X6
Xl2
Xl
XG
Xll
XT
X3
X12
XT
X3
Xll
Costs with Positive
Aquaculture Net
Revenues
$300,515
145,487
300,515
187,987
300,515
240,078
681 ,907
726,957
681,907
776,869
404,683
947,413 •
957,727
404,683
947,413
1,004,418
383,071
1,138,960
1,184,033
383,071
1,138,960
1,233,910
% Reduction in Costs with Zero
Costs from Aquaculture Net
Aquaculture Revenues
62% $385,968
56% 428,468
5025 480,559
10% 809,860
10% 861,951
11% 1,075,366
11% 1,127,457
7% 1,266,913
7% 1,319,004
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TABLE IS—Continued
9
8
15
10
11
12
Strategy
Activated Sludge, Chemical
Addition with Aquaculture
Lagoon
Activated Sludge, Chemical
Addition with Aquaculture
Raceway
Waste Stabilization Lagoon
with Coagulation Filtration
Activated Sludge,
Denitrifi cation System
Activated Sludge with
Coagulation Filtration
System
Activated Sludge with Carbon
Sorption, Ammonia Removal
System
Xl
X4
Xl?
XT
X4
Xll
X2
X?
Xl
X3
X9
Xl
X3
X7
Xl
X3
X7
X8
XlO
Costs with Positive % Reduction in Costs with Zero
Aquaculture Net Costs from Aquaculture Net
Revenues Aquaculture Revenues
$340,633
1,168,256
1,261,393 3% $1,296,209
350,633
1,168,256
1,311,386 3% 1,348,300
301 ,674
1,428,961
385,544
1,024,149
1,759,313
375,974
1,293,515
2,401,865
375,974
1,293,575
2,325,865
3,087,326
3,315,383
-------
The assumption upon which the most pessimistic estimates are made is
that net revenues from the aquaculture system are zero. This implies
that revenue from the sale of aquaculture products is just equal to the
cost of the stock. There is, consequently, no cost reduction in con-
struction and operating outlays through the generation of positive
revenues from the aquaculture systems.
It is significant that in each case, while the total cost of the aqua-
culture system increases, the relative cost ranking of the strategies
is unchanged. This implies that those systems which are cost-effective
with positive net revenues are also cost-effective with zero net rev-
enues. The one exception to this is for objective A in Table 16 when
the Waste Stabilization Lagoon without an Aquaculture system becomes more
cost-effective than the Stabilization Lagoon with an Aquaculture system.
Since potential revenues do not influence the cost-effective decision
in strategy selection, except as indicated above, the major benefits
from aquaculture systems stem from the ability of such systems to
improve water quality relative to costs of treatment.
In addition, this analysis indicates that aquaculture systems cannot
be expected to "pay" the cost of treating water and may, therefore, be
economically unfeasible for private enterprise operations, although
certain private contractual arrangements might be possible. In fact,
Table 19 also shows the percent reduction in costs that can potentially
be gained from aquaculture revenues. It should be clear, however, that
the economic value of aquaculture is in cost savings relative to con-
ventional systems and not in the market value of the aquatic output.
73
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And this remains the case even when net revenues are zero. Aquaculture
systems, therefore, should be considered as a treatment system for
achieving water quality standards at minimum cost.
74
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DISCUSSION
WORK PERFORMED
The research on this project required an interdisciplinary approach and
the research team was comprised of a biologist, an engineer, and two
economists. The engineering work for the project was subcontracted to
the engineering firm, Settle, Dougall, and Spear of Oklahoma City, and
the majority of the engineering work was performed by Mr. George McBryde,
Sanitary Engineer, Oklahoma State Department of Health. The biologist,
i-ir. Ron Jarman, Supervisor of Aquaculture projects, Oklahoma State
Department of Health, was employed part-time on the project by Central
State University, Edmond, Oklahoma. Both economists, Dr. Upton B.
Henderson, and Dr. Frank S. Wert, are members of the faculty of Central
State University, Department of Economics, Edmond, Oklahoma.
Coordination of the project was accomplished under the direction of the
principle investigator, Dr. Henderson, through frequent informal meet-
ings of the research team. Methodology, strategy design and selection,
and all data requirements were established, reviewed, and approved by
all researchers. Therefore, consistency with economic cost-effective
methodology was assured in gathering the biological, engineering, and
economic data needed for the study.
The engineering subcontractor was responsible for providing consulta-
tion on relevant waste water treatment strategy delineation and for
determining the technical effectiveness, in terms of water quality, of
the conventional treatment systems selected. In addition, in consulta-
tion with the project's biologist, the engineer established the
75
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engineering design parameters for the aquaculture raceway and lagoon
systems and provided cost data for the various strategies selected for
cost-effectiveness analysis.
All estimates of fish production, aquaculture water quality parameters,
and the technology of aquaculture were the responsibility of Mr. Ron
Jarman, the project's fisheries biologist. The data on this aspect of
the study were generated from pilot aquaculture projects in the State
of Oklahoma which have been conducted under the auspices of the Oklahoma
State Department of Health and from additional literature sources. In
addition, the biologist established resource requirements and estimated
costs for the operation and maintenance of aquaculture systems.
The economic analysis, research design, revenue estimations, project
administration, and final report preparation were carried out by Central
State University, Department of Economics. The basic tasks performed
by the two research economists were the construction of the cost-
effectiveness model and the determination of basic engineering,
biological, and technical water quality data needed for the model.
Estimates of revenues were made and the market potential for aquaculture
products was determined. All data was collected, analyzed, interpreted,
and presented in final form by the project's economists.
PROBLEM AREAS
The methodology of cost-effectiveness is basically a simple theoretical
framework and is well accepted as a tool of public decision making.
The model requires certain types of data and precision in definitions
of goals. The application to conventional waste water treatment
76
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strategy is well documented. However, its application to aquaculture
as an additional or alternative waste water treatment, strategy poses
many problems. The lack of an adequate data base, at this stage of
the development of aquaculture technology, constitutes the major prob-
lem in employing cost-effectiveness methodology. Water quality
efficiencies and aquaculture production capabilities are not well doc-
umented in the scientific literature.
These data deficiencies limit the outcome of this study. Problems in
biological, economic, and to a lesser degree in engineering data tend
to weaken the project's tentative findings. As a better data base on
waste water aquaculture becomes available, the usefulness of applying
this model to assess the economic viability of aquaculture treatment
systems will increase, thereby enhancing a rational decision making
process.
The estimation of biological data constituted the major research prob-
lem which had to be overcome in the study. There is no reliable
information from controlled studies on the relative efficiency of
varying species of fish and polyculture in terms of water quality.
Most of the literature in the field of aquaculture is concerned with
fish production and marketing, but water quality has not been a major
consideration in these studies. Variation in water quality may result
from different retention rates, seasonal variation in species, species
composition, nutrient loading, and size of fish when harvested.
In addition, actual yields from a waste water aquaculture system may
be a function of water quality variation. Well monitored and controlled
77
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experiments of aquaculture systems are needed to strengthen the data
base in this field. Health considerations, production, and water
quality must be more firmly established before the economic feasibility
of aquaculture is determined with a high degree of certainty.
The economic data base on this study is also weak in terms of projected
estimates of net revenues derived from aquaculture systems. Good
marketing data and research on market acceptability is lacking in the
literature on waste water aquaculture systems. No data is available on
products derived from waste water aquaculture products in this country
when water quality is the prime consideration. Public acceptance of
the technology,as well as the resulting output, is another considera-
tion which must be researched.
The opportunity cost of the nutrients derived from waste water in terms
of an array of outputs is unknown. Recreational benefits as well as
commercial products could be derived from these projects. An integrated
"mechanical-natural systems" approach might yield optimum water quality
and possibly a wide array of various types of outputs. Man-made marshes,
land recycling, aquaculture lakes and lagoons in an integrated system
may be highly feasible, low cost, water treatment alternatives. Such
systems may yield recreational benefits (i.e., waterfowl habitat,
fishing, etc.)* commercial products (timber, cattle, and commercial
fish production), and may result in energy conservation. This study
only considers a very narrow range of alternatives within the confines
of traditional methods of water treatment.
78
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Available engineering data on water quality could also be strengthened.
Better monitoring of seasonal variations is needed to accurately assess
the problems and potentials of aquaculture. The nation's goal for
water quality in the future will have a great bearing on the feasibility
of aquaculture as a waste water treatment facility. As concluded in
this study, aquaculture appears to be a more attractive cost-effective
alternative if standards require plant nutrient reductions before
release to surface waters. Net energy savings and reduced marginal
costs of meeting more stringent standards of water quality appear to
be highly probable.
As a result of the problems discussed above, the conclusions reached
in this report must be interpreted as tentative. Substantiation of
these conclusions must await a more adequate and accurate data base.
SUMMARY AND CONCLUSIONS
This study attempted to ascertain the economic viability of aquacul-
ture as an alternative treatment system to achieve mandated water
quality standards. The emphasis was placed on small municipalities
which face major financial barriers to achieve the nation's commitment
to clean water.
A cost-effectiveness model was utilized. This model allowed compari-
sons of varying water quality standards and the use of technically
feasible alternative treatment strategies to-achieve these standards
in terms of costs.
Conventional and aquaculture systems were selected on the basis of
79
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technical feasibility. Water quality standards and the effectiveness
of conventional systems to achieve these goals were determined from
secondary source material of previous studies conducted under the
auspices of the Environmental Protection Agency and data obtained from
monitoring studies of this type of treatment system in the State of
Oklahoma. The effectiveness of aquaculture to obtain given reductions
in the level of pollutants was obtained from a single demonstration
project conducted in Oklahoma (Quail Creek).
Potential production of fish and bait products from aquaculture were
determined on the basis of the assumption that production from a waste
water lagoon would be equal to fertilized fish culture ponds. Potential
revenues from production were determined on the basis of current price
quotes received from commercial fish culturists in three Southwestern
states.
All cost estimates for conventional waste water treatment systems were
derived from standard engineering cost publications. Cost estimates
and design of aquaculture systems were provided by the consulting
engineer and the biologist. These systems were designed to facilitate
fish culturist practices. The selection of species and the species
composition of polyculture were delineated on the basis of previous
research. The results of this research supports the suitability for
rearing aquatic animals in sewage waste water aquaculture systems.
Variation in water quality and susceptibility to biological disruption,
as it relates to the selection of species, was not determined in this
study.
80
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Fifteen (15) technically feasible sewage treatment strategies were
examined. Aquaculture raceways were incorporated into five (5) strat-
egies as the last stage in the total treatment process and lagoon
aquaculture systems were used in an additional six (6) strategies.
The remaining four strategies were solely mechanical-chemical conven-
tional treatment systems at all stages in the process of water treatment.
All strategies were then analyzed to determine the most cost-effective
systems.
A standard present value approach to all annual costs and revenues was
used, and a discount rate of 5-7/8 percent, as recommended for water
development and related projects, was employed. The present value of
the net cost of each stage of each strategy was determined. EPA cost-
effective guidelines were employed.
The economic analysis of the various strategies was first based on
multiple objective levels for BOD5 and suspended solids, with secondary
treatment standards as the minimum objective. A second multiple objec-
tive level of water quality was defined in terms of plant nutrient
removal. Finally, a tertiary treatment objective was defined for all
pollutants considered. The various strategies were examined in terms
of their ability to meet various reduction levels for pollutants and
accepted or rejected on the basis of relative costs.
When the ability to reduce suspended solids and BODs was considered
aquaculture strategies were always more cost-effective than the corres-
ponding conventional alternatives when aquaculture was capable of
81
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achieving the desired level of BOD5/SS removal. There were significant
and substantial differences in cost in every case, with cost differen-
tials between aquaculture and conventional strategies ranging from a
low of 3.8 percent to a high of 72 percent.
When nutrient removal was established as a goal of treatment,
again aquaculture alternatives were cost reducing relative to conven-
tional systems when aquaculture was capable of achieving stated P/TKN
objectives. The cost differentials between conventional and aquaculture
strategies for those objectives ranged from a low of 38 percent to a
high of 94 percent. When aquaculture was not capable of meeting a
given objective it was, of course, deemed not to be cost-effective.
In those cases, however, the inability of aquaculture probably reflects
lack of knowledge as to water quality parameters from aquaculture
systems as well as lack of knowledge relative to the technology of
water treatment processes by those systems.
This study concludes that Strategy 2 Waste Stabilization Lagoon with an
Aquaculture Lagoon is the most cost-effective system to meet current secondary
standards. As a result of the aquaculture unknowns for advanced treat-
ment processes, the most cost-effective system to meet tertiary levels
is Strategy 12 Activated Sludge plant with Carbon Sorption, Ammonia
•Removal. The system was cost-effective, however, only because no
other strategy was capable of meeting such high levels of water
quality.
The potential revenue generated from aquaculture was not critical to
82
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the economic analysis in terms of a cost-effective decision model. The
reduction in costs from the adaption of an Aquaculture alternative
was less dramatic when zero net revenues were assumed, but the relative
cost ranking of the strategies remained the same. Aquaculture waste
water alternatives appears to be economically attractive regardless
of the market for products if, in fact, such systems achieve the water
quality levels indicated by the conservative estimates made in this
study.
At this stage of our knowledge aquaculture waste water treatment systems
are economically viable alternatives. The potential for waste water
aquaculture systems to achieve even better water quality is very high,
and is probably species dependent and related to water retention time
in the aquaculture system, plus the length of the food chain established.
These facets of aquaculture should be determined as quickly as possible
since this study has shown the great potential for cost reduction.
The susceptibility to biological disruptions related to temperature
variation could possibly be overcome with a polyculture designed to
function under most climatic conditions within a given region. Possibly
seasonal rotation of the composition of the polyculture species could
resolve this difficulty. Again, this knowledge would improve the
economic viability of waste water treatment aquaculture systems.
The potential of waste water aquaculture systems to produce usable
products is obviously larger than immediate markets for stocking
and minnows for bait purposes. In an increasingly crowded
world the production of protein from low energy and low land intensive
83
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technology will become increasingly more attractive from an economic
point of view. Higher prices for fossil fuels and land will shift
economic advantages away from current agriculture practices. The more
efficient converters of plant energy typically found in aquatic systems,
coupled with zero priced nutrients in municipal waste water to produce
plant energy, has great economic potential for the future. Sewage
treatment plants are long-term investments by society and future markets
can be expected to make aquaculture an even more attractive technology
for the treatment of municipal waste water.
This study represents a "first attempt" to quantify the potential
economic relationships associated with aquaculture as a waste treatment
technology. Although the study raises as many questions as it answers,
wastewater aquaculture is definitely a low cost alternative to conven-
tional treatment technology and, it is felt should be given serious
consideration at this time as an economically feasible treatment system.
84
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BIBLIOGRAPHY
Allen, George H. "The Constructive Use of Sewage, with Particular Ref-
erence to Fish Cultures," FAQ Technical Conference in Marine
Pollution and Its Effect on Living Resources and Fishing.
(Rome 9/18, December, 1970) F.I.R.:MP/70/R-13.
. "A Preliminary Bibliography on the Utilization of Sewage in
Fish Culture." FAQ Fisheries Circular, No. 308, March, 1969.
, and Balfour Hepher. "Recycling of Wastes Through Aquaculture
and Constraints to Wider Application." Unpublished paper, 1976.
, and Larry Dennis. Report on Pilot Aquaculture System Using
Domestic Waste Waters for Rearing Pacific Salmon Smolts. Waste-
water Use in the Production of Food and Fiber—Proceedings.
Environmental Protection Agency, Washington, D. C. Report No.
EPA 660/2-74-041, June, 1974, pp. 162-198.
Altman, R. W. "Investigate Before You Invest." Proceedings, Oklahoma
State University, Fish Farming Conference, 1970.
Bailey, W. M., F. P. Meyer, J. M. Martin and D. L. Gray. "Farm Fish
Production in Arkansas During 1972," Proceedings, 27th Annual
Conference, S. E. Association, Game and Fish Commission, 1973,
pp. 750-757.
Carpenter, R. LeRoy, Mark S. Coleman and Ron Jarman. "Aquaculture as
an Alternative Waste Water Treatment System." Unpublished
manuscript, 1975.
Harold K. Mai one, Ara F. Roy, Aaron L. Mitehum, Herbert E.
Beauchamp and Mark S. Coleman. "The Evaluation of Microbial
Pathogens in Sewaqe and Sewage-Grown Fish." Waste Water Use in
the Production of Food and Fiber—Proceedings. Environmental
Protection Agency, Washington, D. C. Report No. EPA 660/2-74-041,
June, 1974, pp. 46-55.
Clemens, H. P. "Some Comments on Production, Harvesting, and Marketing
of Channel Catfish in Oklahoma." Oklahoma State University,
Fish Farming Conference, 1970, pp. 22-28.
Coleman, Mark S., J. P. Henderson, H. G. Chichester, and R. L. Carpenter.
"Aquaculture as a Means to Achieve Effluent Standards." Wastp
Water Use in the Production of Food and Fiber—Proceedings.
Environmental Protection Agency, Washington, D. C. Report No.
EPA 660/2-74-041, June, 1974, pp. 199-214.
and R. Jarman. "Comparative Role of Non-Point Sources and
Municipal Wastes in the Eutrophication. of Oklahoma Reservoirs."
Unpublished manuscript, 1975.
85
-------
"Cost Effective Analysis." Appendix A to 40 CFR, part 35, Federal
Register, Vol. 38, No. 174, September 10, 1973.
Cost-Effective Waste Water Treatment Systems. Final Report, U. S.
Environmental Protection Agency, Office of Water Operations,
Washington, D. C., 1975.
Davidson, Paul, F. G. Adams, and J. Seneca. "The Social Value of Water,
Recreational Facilities Resulting From an Improvement in Water
Quality, The Delaware Estuary." Kneese and Smith, eds., Water
Research, Johns Hopkins Press, Baltimore, 1966, pp. 175-224.
Demonstrated Technology and Research Needs for Reuse of Municipal Waste
Water. Cincinnati, Ohio, National Environmental Research
Center, E.P.A., May, 1975.
DiGregorio, David, £t al_. Cost of Waste Water Treatment Processes.
Cincinnati: U. S. Department of the Interior, December, 1968.
Dinges, R. Ecology of Daphnia in Stabilization Ponds. Texas State
Department of Health Publication, 1973, 155 pp.
. The Availability of Daphnia for Water Quality Improvement and
as an Animal Food Source. Waste Water Use in the Production of
Food and Fiber—Proceedings. Environmental Protection Agency,
Washington, D. C., Report No. EPA 660/2-74-041, June, 1974,
pp. 142-161.
. "Biological Consideration in Stabilization Pond Design."
Paper presented at 56th Texas Water Utilities Short School,
Texas A & M University, 1974, 17 pp.
, and A. Rust. "The Role of Daphnia in Waste Water Oxidation
Ponds." Public Works, October, 1972, pp. 89-91.
Dobie, J., 0. L. Meechan, S. F. Sniezko, and G. H. Washburn. "Raising
Bait Fishes." Circular 35, U. S. Department of Interior, 1957.
Donaszy, Erno. Principles of Sewage Treatment Through Utilization in
Fish Ponds. Waste Water Use in the Production of Food and Fiber—
Proceedings. Environmental Protection Agency, Washington, D. C.,
Report No. EPA 660/2-74-041, June, 1974, pp. 546-556.
Duffer, William R. "Lagoon Effluent Solids Control by Biological Harvest-
ing." Symposium on Upgrading Waste Water Stabilization Ponds tc
Meet New Discharge Standards. Environmental Protection Agency
and Utah State University, (Mimeographed Report), August, 1974.
Eilers, Richard G. Condensed One-Page Estimates for Waste Water Treatment.
Cincinnati: Environmental Protection Agency, November, 1970.
Ehrlich, S. "Two Experiments in the Biological Clarification of Stabiliza-
tion Pond Effluents." Hydrobiologia (Israel), 27: 80-90, 1966.
86
-------
Environmental Protection Agency. Evaluation of Municipal Sewage Treat-
ment Alternatives—Final Report. Washington, D. C., February,
1974.
Environmental Protection Agency. A Guide to the Selection of Cost
Effective Waste Water Treatment Systems, EPA 430/9-74-002,
Washington, D. C., July, 1975.
Freeman, A. Myrick, III, Robert H. Haveman, and Allen V. Kneese.
The Economics of Environmental Policy. New York: John Wiley
& Sons, Inc. , 1973.
Gosselink, James G., Eugene P. Odum, and R. M. Pope. The Value of the
Tidal Marsh. Gainesville, Fla.: Urban and Regional Develop-
ment Center , May, 1973.
Greer, D. E., and C. D. Ziebell. "Biological Removal of Phosphates
from Water." J. Water Pollution Control Federation.
44, 12: 2342-2348, 1972.
Hallock, R. J. and C. D. Ziebell. "Feasibility of a Sport Fishery in
Tertiary Treated Waste Water." J. Water Pollution Control
Federation. 42:1656-1665.
Hepher, B. "Supplementary Feeding in Fish Cultures." Separatum.
Switzerland, 1972.
Hinesly, T. D. Water Renovation for Unrestricted Re-Use.
Muggins, Thomas G. and Roger W. Bachmann. Production of Channel Catfish
in Tertiary Treatment Ponds. Iowa State Water Resources Research
Institute, Ames, Iowa, June, 1969.
Huguenin, John E. and John H. Ryther. "Experiences with a Marine Aqua-
culture-Tertiary Sewage Treatment Complex." Waste Water Use
in the Production of Food and Fiber—Proceedings. Environmental
Protection Agency, Washington, D. C. Report No. 660/2-74-041.
June, 1974, pp. 377-386.
Kneese, A. V., R. U. Ayres, and R. C. d'Arge. Economics and the
Environment: A Materials Balance Approach. Resources for the
Future, Washington, D. C., 1970
Kneese, Allen V., and Stephen C. Smith, eds. Water Research.
Baltimore: Johns Hopkins Press, 1966 , pp. 175-224.
Konefes, John L. and Roger W. Bachmann. "Growth of the Fathead Minnow
in Tertiary Treatment Ponds." Proceedings. Iowa Academy of
Science, 77:104-111, 1970.
87
-------
Las Virgenes Municipal Water District, Calabassas, California. "Ter-
tiary Treatment with Control lea Ecological System." Environmental
Protection Agency, Washington, D. C. Report No. EPA 660/2-73-022.
December, 1973, 43 pp.
Mackenzie, C. R. and G. D. Campbell. "Hygenic Evaluation of the Food
Fish Tilapia melanopleura and Tilapia mossambica Nurtured in
Sewage Effluent." S. A. Medical Journal, September, 1973, p. 968.
Manual of Instruction for Sewage Treatment Plant Operators. Albany,
New York: Health Education Service, prepared by New York State
Department of Health.
Marsden, J. R., D. E. Pingry, and S. Whinston. Economics of Waste Water
Treatment: The Role of Regression. Office of Water Resources
Research, Washington, D. C.
McMichael, Walter F. Cost of Dissolved Air Flotation Thickening of
Waste Activated Sludge at Municipal Sewage Treatment Plants.
Cincinnati: National Environmental Research Center, February,
1974.
. Costs of Hauling and Land Spreading of Domestic Sewage Treat-
ment Plant Sludge. Cincinnati: National Environmental Research
Center, February, 1974.
McShan, Michael, Norman M. Trieff, and Dov Grajcer. "Biological Treat-
ment of Waste Water Using Algae and Artemia." Journal of Water
Pollution Control Federation, 46(7):1742-1750, July, 1974.
Methodology for Economic Evaluation of Municipal Water Supply/Waste
Water Disposal Including Considerations of Seawater Distillation
and Waste Water Renovation. San Francisco: Bechtel Corporation,
August, 1970.
Meyer, F. P., D. L. Gray, W. P. Mathis, J. M. Martin and B. R. Wells.
"Production and Returns from the Commercial Production of Fish
in Arkansas During 1966." Proceedings, 21st Annual Conference
of S. E. Association of Game and Fish Commission, pp. 525-531.
, D. S. Godwin, R. Boyd, J. M. Martin, D. L. Gray, and .W. P.
Mathis. "Fish Production in Arkansas During 1969 as Compared to
Other States." Proceedings, 24th Annual Conference of S. E.
Association of Game and Fish Commission, 1970, pp. 497-506.
Mihursky, J. A. "On Using Industrial and Domestic Waste in Aquaculture.
Agriculture Engineering, November, 1969, pp. 667-669.
Oklahoma Commercial Fishery Statistics, 1974. Federal Aid Project No.
2-240-K-l, Oklahoma Department of Fish and Game, Oklahoma City,
September 2, 1975.
-------
Patterson, W. L., j2t al_. Estimating Costs and Manpower Requirements
for Conventional Waste Water Treatment Facilities. Washington,
D. C.: National Technical Information Service, U. S. Depart-
ment of Commerce, October, 1971.
Peskin, Henry M. and Eugene P. Seskin, eds. Cost Benefit Analysis and
Water Pollution Policy. Washington, D. C.: The Urban Insti-
tute, 1975.
Porter, J. Winston, et al_. Cost Estimating Guidelines for Waste Water
Treatment Systems. San Francisco: Bechtel Corporation, July,
1970.
Prather, E. E. "Experiments on the Commercial Production of Golden
Shiners." Proceedings, 10th Annual Conference of S. E. Game
and Fish Commission, pp. 150-155, 1957.
Prather, E. E., J. R. Fielding, H. S. Swingle, and M. C. Johnson.
"Production of Bait Minnows in the Southeast." Circular 112,
Agricultural Experiment Station, Alabama Polytechnic Institute,
1954.
Reid, G. W. "Algae Removal by Fish Production." Proceedings of Water
Resources, Symposium No. 9. University of Texas Press, Austin,
Texas, 1976, p. 417-421.
Retail Market Potential for Farm Cultured Catfish. Agricultural Experi-
ment Station, Bulletin 799, University of Arkansas, Fayetteville,
Arkansas, May, 1975.
Rytler, J. H. "The Use of Flowing Biological Systems in Aquaculture."
Sewage Treatment, Pollution Assay and Food Chain Studies.
WHOI-73-2, 1973.
Sawyer, C. N. Basic Concepts of Eutrophication. Journal of Water
Pollution Control Federation. 38:737-744, 1966.
Sawyer, C. N., J. B. Lackey, and A. T. Lenz. "Investigations of the
Odor Nuisance Occurring in the Madison Lakes, particularly Lakes
Monona, Waubeas, and Kegonsa from July, 1943 to July, 1944."
Report of the Governor's Commission, State of Wisconsin.
Schaat, W. E. "Fish Population Models: Potential and Actual Links to
Ecological Models."
Schroder, Gerald L. "Some Effects of Stocking Fish in Waste Treatment
Ponds." Water Research. Great Britain, The Pergamon Press,
1975.
Singer, Neil M. Public Microeconomics. Boston: Little & Brown, 1972.
Chapter 12.
89
-------
Smith* Robert. A Compilation of Cost Information for Conventional and
Advanced Waste Water Treatment Plant and Processes. Cincinnati:
Robert A. Taft Sanitary Engineering Center, December, 1967.
, and Walter F. McMichael. Cost and Supply Analysis for Alum
and Methanol Used in Waste Water Treatment. Cincinnati:
Environmental Protection Agency, National Technical Information
Service, August, 1971.
. Cost-Effectiveness Analysis for Water Pollution Control.
Cincinnati: National Environmental Research Center, Office of
Research and Development, Environmental Protection Agency,
August, 1974.
. Cost and Performance Estimates for Tertiary Waste Water
Treating Processes. Cincinnati: Federal Water Pollution
Control Administration, June, 1966.
*»
, eijil_. Costs of Waste Water Renovation. Cincinnati:
Environmental Protection Agency, November, 1971.
. The Cost of Dispersed Floe Nitrification and Denitrification
for Removal of Nitrogen from Waste Water. Cincinnati: Environ-
mental Protection Agency, November, 1970.
, and Richard G. Eilers. Waste Water Treatment Plant Cost
Estimating Program Documentation. Cincinnati: Environmental
Protection Agency, Water Quality Office, March, 1973.
Steele, John H. The Structure of Marine Ecosystems. Harvard University
Press, 1974.
Swingle, H. S. "Experiments on Growing Finger!ing Channel Catfish to
Marketable Size in Ponds." Proceedings, 12th Annual Conference
of S. E. Association of Game and Fish Commission, pp. 63-72,
1958.
Tannenbau, Still ings, and Schrimshaw, eds. The Economics, Marketing
and Technology of Fish Protein Concentrate. Cambridge, Mass.:
The M. I. T. Press, 1974.
Trimberger, J. "Production of Fathead Minnows (Pimephales Promelas)
in a Municipal Waste Water Stabilization System." Michigan
Department of Natural Resources, Fisheries Division. (Mimeo-
graphed Report), 1972, 5 pp.
United States Department of Commerce. A Statistical Reporting System
for the Catfish Fanning Industry, Methodology and 1970 Results.
Washington, D. C.: U. S. Government Printing Office, 1972.
90
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APPENDIX
SCHEMATIC PRESENTATION OF TREATMENT STRATEGIES
91
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STAGE I
STAGE II
10
ro
PRIMARY WASTE
STABILIZATION
LAGOON
SECONDARY WASTE
STABILIZATION
LAGOON
AQUACULTURE
RACEWAY
SURFACE
WATER
STRATEGY NO. 1 -- WASTE STABILIZATION LAGOON WITH AQUACULTURE
-------
STAGE I
STAGE II
PRIMARY WASTE
STABILIZATION
LAGOON
SECONDARY
STABILIZA-
TION
LAGOON
AQUACULTURE
LAGOON
SURFACE
WATER
STRATEGY NO. 2 — WASTE STABILIZATION LAGOON WITH AQUACULTURE LAGOON
-------
IO
-p.
PRIMARY WASTE
STABILIZATION
LAGOON
STAGE I
SECONDARY WASTE
STABILIZATION
LAGOON
WITH
FISH
SURFACE
WATER
STRATEGY NO. 3 -- WASTE STABILIZATION LAGOON WITH FISH
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cn
STAGE I
PRIMARY
TREATMENT
STAGE II
TRICKLING
FILTER
SECONDARY
SEDIMENTA-
TION
STAGE III
AQUACULTURE
RACEWAY
SURFACE
WATER
STRATEGY NO. 4 -- TRICKLING FILTER WITH AQUACULTURE RACEWAY
-------
STAGE II
en
STAGE I
PRIMARY
TREATMENT
TRICKLING
FILTER
SECONDARY
SEDIMENTA
TION
SLUDGE
STAGE III
AQUACULTURE
LAGOON
SURFACE
WATER
STRATEGY NO. 5 — TRICKLING FILTER WITH AQUACULTURE LAGOON
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>l
STAGE I
PRIMARY
TREATMENT
STAGE II
ACTIVATED
SLUDGE
STAGE III
AQUACULTURE
RACEWAY
SURFACE
J«IATER
VO
SLUDGE
HANDLING
STRATEGY NO. 6 -- ACTIVATED SLUDGE WITH AQUACULTURE RACEWAY
-------
STAGE I
STAGE II
STAGE III
PRIMARY
TREATMENT
ACTIVATED
SLUDGE
AQUACULTURE
LAGOON
SURFACE
WATER
00
SLUDGE
HANDLING
STRATEGY NO. 7 -- ACTIVATED SLUDGE WITH AQUACULTURE LAGOON
-------
STAGE I
STAGE II
STAGE III
PRIMARY
TREATMENT
ACTIVATED
SLUDGE WITH
CHEMICAL
ADDITION
SLUDGE
HANDLING
AQUACULTURE
RACEWAY
SURFACE
WATER
STRATEGY NO. 8 -- ACTIVATED SLUDGE, CHEMICAL ADDITION, WITH AQUACULTURE RACEWAY
-------
STAGE I
STAGE II
STAGE III
PRIMARY
TREATMENT
ACTIVATED
SLUDGE WITH
CHEMICAL
ADDITION
AQUACULTURE
LAGOON
SURFACE
WATER
o
o
SLUDGE
HANDLING
STRATEGY NO. 9 -- ACTIVATED SLUDGE, CHEMICAL ADDITION, WITH AQUACULTURE LAGOON
-------
STAGE I
PRIMARY
TREATMENT
STAGE II
ACTIVATED
SLUDGE
STAGE III
NITRIFICATION
DENITRIFICATION
SURFACE
WATER
SLUDGE
HANDLING
STRATEGY NO. 10 -- ACTIVATED SLUDGE, NITRIFICATION/DENITRIFICATION SYSTEM
-------
o
ro
STAGE I
PRIMARY
TREATMENT
STAGE II
ACTIVATED
SLUDGE
SLUDGE
HANDLING
STAGE III
COAGULATION
FILTRATION
SLUDGE
HANDLING
SURFACE
WATER
STRATEGY NO. 11 -- ACTIVATED SLUDGE WITH COAGULATION FILTRATION SYSTEM
-------
STAGE I
STAGE II
STAGE III
o
CO
PRIMARY
TREATMENT
•STAGE IV
ACTIVATED
SLUDGE
SLUDGE
HANDLING
COAGULATION
FILTRATION
SURFACE
WATER
CARBON
SORPTION
STAGE'V
AMMONIA
REMOVAL
STRATEGY NO. 12 -- ACTIVATED SLUDGE - CARBON SORPTION - AMMONIA REMOVAL SYSTEM
-------
o
•£>
STAJ3E I
STAGE II
EXTENDED
AERATION
AQUACULTURE
RACEWAY
SURFACE
WATER
STRATEGY NO. 13 -- EXTENDED AERATION WITH AQUACULTURE RACEWAY
-------
o
en
STAGE I
STAGE II
EXTENDED
AERATION
AQUACULTURE
LAGOON
SURFACE
WATER
STRATEGY NO. 14 -- EXTENDED AERATION WITH AQUACULTURE LAGOON
-------
o
en
STAGE I
PRIMARY
WASTE
STABILIZA-
TION LAGOON
SECONDARY
WASTE
STABILIZA-
TION LAGOON
STAGE II
COAGULATION
FILTRATION
I
SLUDGE
HANDLING
SURFACE
WATER
STRATEGY NO. 15 - WASTE STABILIZATION LAGOON WITH COAGULATION FILTRATION
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-293
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
ECONOMIC ASSESSMENT OF WASTE WATER AQUACULTURE
TREATMENT SYSTEMS
5. REPORT DATE
December 1976
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Upton B. Henderson
Frank S. Wert
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORG \NIZATION NAME AND ADDRESS
Central State University
Department of Economics
Edmond, Oklahoma 73034
10. PROGRAM ELEMENT NO.
1BC611 «
11. CONTRACT/GRANT NO.
R803623
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Lab.
Office of Research and Development
U. S. Environmental Protection Agency
Ada, Oklahoma 74820
- Ada, OK
13. TYPE OF REPORT AND PERIOD COVERED
Final - 3/75 - 7/76
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16AHSTRACT •
This study attempted to ascertain the economic viability of aquaculture
as an alternative to conventional waste water treatment systems for small
municipalities in the Southwestern region of the United States. A multiple
water quality objective level cost-effectiveness model was employed. A
total of fifteen waste water treatment strategies, eleven with aquaculture
systems and four without aquaculture, were examined. Estimates were made
of the technical effectiveness and the present value of costs for all
strategies. Estimates of the current value of revenues derived from sale
of products produced in the aquaculture systems were made, and the impact
of such revenues on total costs was analyzed.
In all cases, when aquaculture was deemed capable of achieving a given water
quality objective, the aquaculture system compared to a conventional system
was cost-effective. The cost differentials between aquaculture and con-
ventional strategies were highly significant ranging from a low 3.8 percent
to a high of 94 percent. While certain data limitations exist, especially
in the area of water quality estimates, aquaculture systems appear to be
low cost alternatives to conventional waste water treatment systems.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Aquaculture
Cost effectiveness
Wastewater treatment
Wastewater utilization
Fish culture
13 B
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport/
UNCLASSIFIED
21. NO. OF PAGES
119
20. SECURITY CLASS (This page I
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
107
ft Hi HWDMIIBIT PmitTIWJ OfWfc 1977-7 S 7 - 0 56 / 5 5 46
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