EPA-6 6 0/2-74-041
JUNE 1974
Environmental Protection Technology Series
Wastewater Use in the Production
of Food and Fiber—Proceedings
Office of Research and Development
U.S. Environmental Protection Agency
Washington, DC 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Aqency, 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.
EPA REVIEW NOTICE
This report has "been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval does
not signify that the contents necessarily reflect the views
and policies of the Environmental Protection Agency, nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.
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EPA- 660/2-74-041
June 1974
WASTEWATER USE IN THE PRODUCTION
OF FOOD AND FIBER—PROCEEDINGS
Proceedings of the Conference held at
Oklahoma City, Oklahoma
March 5-7, 1974
Cosponsored by:
OKLAHOMA STATE DEPARTMENT OF HEALTH
Oklahoma City,, Oklahoma
CALIFORNIA STATE UNIVERSITY, HUMBOLDT
Humboldt State University Sea Grant Program
Arcato, California
MIDCONTINENTENVIRONMENTAL CENTER ASSOCIATION
Tulsa, Oklahoma
EAST CENTRAL OKLAHOMA STATE UNIVERSITY
Oklahoma Environmental Information and Media Center
Ada, Oklahoma
U.S. ENVIRONMENTAL PROTECTION AGENCY
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma
BUREAU OF SPORT FISHERIES AND WILDLIFE
Fish Farming Experimental Station
Stuttgart, Arkansas
UNIVERSITY OF OKLAHOMA
College of Health and Allied Health Professions
Oklahoma City, Oklahoma
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For Mto by the Superintendent of Document*, 17.8. Government Printing Office Washington, D.C. 20402 - Price S5.J5
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ABSTRACT
A conference was convened to bring together an interdisciplinary
group of investigators for the purpose of critically reviewing the present
base of scientific knowledge relating to benefits and constraints of using
wastewaters for production of food and fiber. Those gathered represented
the fields of public health, engineering, agriculture, aquaculture, and
other related scientific areas. There were 27 papers presented at the
conference covering technical restraints, aquacultural approaches, agri-
cultural approaches, nontechnical constraints, and new or integrated
experimental systems. In addition to those papers presented at the con-
ference, nine others have been included to make a total of 36 papers in
this conference Proceedings.
Papers in the two sections on potential restraints cover topics such
as historical instances of disease transmission, possible transport of micro-
bial pathogens through the food chain, legal implications, and sociological
reactions. The aquaculture section deals primarily with experimental studies
including such diverse approaches as culture ofdaphnia, salmon smolts, and
water hyacinth. The agriculture section emphasizes the use of waste water
for crop production and the papers presented include case histories for
long-term operating systems, as well as data from experimental studies.
n
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TABLE OF CONTENTS
Page
Abstract
Foreword
Sponsors
List of Speakers
11
vii
ix
x
PARTI INTRODUCTORY SESSION
Review of American Public Works Association Study of
Facilities Utilizing Land Application of Wastewater
Richard H. Sullivan
Wastewater Utilization in Integrated Aquaculture and
Agriculture Systems
B. Hepher and C. L, Schroeder
PART 2 TECHNICA L RES TRAI NTS
Diseases Transmitted by Foods Contaminated by Wastewater 16
Frank L. Bryan
The Evaluation of Microbial Pathogens in Sewage and
Sewage-Crown Fish 46
R. LeRoy Carptenter, Harold K. Malone, Ara F.
Roy, Aaron L. Mitchum, Herbert E. Beauchamp
and Mark S. Coleman
Morbidity Risk Factors from Spray Irrigation with Treated
Wastewaters 56
Geoffrey B. Stanford and Rafael Tuburan
Permissible Levels of Heavy Metals in Secondary Effluent
for Use in a Combined Sewage Treatment-Marine
Aquaculture System I. Monitoring During Pilot Operation 65
W. B. KerfootandS. A. Jacobs
Permissible Levels of Heavy Metals in Secondary Effluent
for Use in a Combined Sewage Treatment-Marine
Aquaculture System II. Development of Guidelines by
Method of Additions 79
W. B. KerfootandG. A. Redmann
in
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Table of Contents (continued)
Calculated yield of Sewage Lagoon Biomass, A Plan for
Production, and Some of the Problems Inherent in Using
Biomass or Lagoon Water for Production of Food and Fiber
Karl Schurr and J, M. Colombek
Page
102
PART 3 A QUA CUL TURE
Analysis of Sewage Lagoon Biomass Water Soluble Vitamins
by Microbiological Techniques
Nancy M. Bakaitis
Feed and Fiber from Effluent—Grown Water Hyacinth 116
L. O. Bagnall, T.deS. Furman, J. F. Hentges, Jr.,
W. J. Nolan and R. L. Shirley
The Availability of Daphnia for Water Quality Improvement
and as an Animal Food Source 742
Ray Dinges
Report on Pilot Aquaculture System Using Domestic
Wastewaters for Rearing Pacific Salmon Smolts 162
George H. Allen and Larry Dennis
Aquaculture as a Means to Achieve Effluent Standards 199
Mark S. Coleman, James P. Henderson, H. G.
Chichester and R. LeRoy Carpenter
PART H AGRICULTURE
An Experiment in the Eutrophication of Terrestrial
Ecosystems with Sewage: Evidence of Nitrification in
a Late Successionaf Forest
G. M. Woodwell, J. Bollard, J. Clinton,
M. Small and E. V. Pecan
Irrigation with Waste water at Bakers field, California
Ronald W. Crites
Nutritive Value of Aerobically Treated Livestock and
Municipal Wastes
D. L. Day and B. G. Harmon
Grass Filtration for Final Treatment of Wastewater
R. M. Butler, J. V. Husted and J. N. Walter
215
229
240
256
IV
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Table of Contents (continued)
Use of Cattle Feed/of Runoff in Crop Production
C. IV. Wai ting ford, L. S. Murphy, W. L.
Powers, H. L. Manges, and L. A. Schmid
Irrigation of Trees and Crops with Sewage Stabilization
Pond Effluent in Southern Michigan
Jeffrey C. Sutherland, John H. Cooley,
Daniel C. Neary and Dean H. Urie
Uses of Power Plant Discharge Water in Greenhouse
Production
B. J. Bond, W. K. Furlong, L. D. King,
C. E. Madewell and J. B. Martin
Page
273
295
PART 5 NONTECHNICAL RESTRAINTS
Legal Constraints on the Use of Wastewater for Food and
Fiber 330
William R. Walker and William E. Cox
Social, Political, Regulatory and Marketing Problems of
Marine Waste-Food Recycling Systems 344
John E. Huguenin and Judy T. Kildow
Recycling for a Purpose—But for What Purpose? A
Sociologist's View 357
Lewis H. Irving
PART 6 NEW OR INTEGRA TED SYSTEMS
The Michigan State University Water Quality
Management Program
T. G. Bahr, R. C. Ball and H. A. Tanner
Experiences with a Marine Aquaculture-Tertiary
Sewage Treatment Complex
John E. Huguenin and John H. Ryther
Polycultural Wastewater Reclamation at California
Polytechnic State University—An Academic
Instructional System
Richard J. Krejsa
362
377
387
v
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Table of Contents (continued)
PART 7 ADDITIONAL PAPERS CONTRIBUTED FOR PUBLICATION
Coliform and Phytoplankton Studies in a Brackish Water
Aquacu/ture Pond Fertilized with Domestic Wastewater
Robert F. Donnelly and Tommy T. Inouye
Mineral Quality of Fish Pond Effluent Related to Soil
Properties and Crop Production
L. H. Hileman
The Dialectics of a Proposal on Biological Control of
Eutrophication in Sewage Lagoons
S. V. Lin
The Harvesting of Algae as a Food Source from Wastewater
Using Natural and Induced Flocculation Techniques
Joseph L. Pavoni, Steven W. Keiber and
Gary T. Boblitt
Critical Variables in Food-Item Population Dynamics
in a Waste-Water Aquaculture System
Joseph E. Powers
The Feasibility ofPenaeid Shrimp Culture in Brackish
Ponds Receiving Treated Sewage Effluent
William L. Rickards
Standing Crops ofBenthic Fauna in Marine Aquaculture
Ponds Using Reclaimed Water
Thomas R. Sharp
Controlled Eutrophication: Sewage Treatment and Food
Production
J. Glenn Songer, N. M. Trieff, Rodney F.
Smith and Dov Crajcer
Principles of Sewage Treatment Through Utilization in
Fish Ponds
Erno Donas zy
Page
404
472
477
435
497
504
573
529
546
PART 8 APPENDICES
A. Program Committees
B. List of Participants
557
559
VI
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FOREWORD
The topic of using domestic wastewater in the production of food and
fiber is of great importance to three distinctly different groups in
our society:
(1) Those persons living in arid or semiarid regions where econom-
ic growth, industry and agriculture hang on the thin thread
of dwindling ground water supply. Reclamation and reuse of
wastewater, even if only for irrigation of agriculture crops,
would not only free a large percentage of treated water for
municipal needs but would also minimize contamination of our
primary water sources and provide cost benefits compared to
the cost of developing new sources of water.
(2) Those persons living in developing countries where protein is
produced in insufficient quantities to sustain an increasing
population with new demands for better nutrition. The cost
and the shortage of fertilizer have severely damaged the
"green revolution." Nitrogen and phosphorus of wastewater,
all too often rushed out of sight like the proverbial step-
children, are more and more looked upon as agricultural assets
rather than municipal liabilities.
(3) Those persons who fall into the category of concerned taxpay-
ers and those municipal officials who are charged with meeting
federal and state water quality standards with precious tax
dollars. The beneficial use of domestic wastewater for eco-
nomic gain is no longer a laboratory curiosity or the practice
of poverty stricken foreigners. There are hundreds of proj-
ects throughout the United States and thousands in Europe and
Asia where wastewater in various degrees of treatment is used
for irrigation of forage crops, hardwood and Christmas trees,
fish and shrimp culture, powerplant cooling water, factory
process water and even recreation. The removal of nitrogen
and phosphorus by trees, crops, or fishes not only produces a
saleable product but greatly reduces the size and operational
budget of mechanical and chemical treatment plants.
The conference and the proceedings that follow have been the result of
much thought, planning and effort on the part of persons of many diff-
erent professional, governmental, and business disciplines. There were
173 participants from 27 states, Canada, Virgin Islands, and Israel.
VII
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Many facets of the use of wastewater in the production of food and
fiber were discussed in a scholarly, critical manner. The technical
and public health constraints were given extra attention.
The success of the conference was largely due to the efforts of Dr.
George Allen and his excellent program committee; Charles Newton and
his local arrangements committee; Lovena Eaker, my long-suffering sec-
retary; and especially Toni Morrow who wore not only the hat of pub-
licity chairman but that of details clerk, timekeeper, memory bank,
bookkeeper, complaint solver, all with a constant smile. To these and
Dr. B. Hepher, who keynoted the conference with many constructive com-
ments, I extend my heartfelt gratitude.
R. LeRoy Carpenter, M.D., M.P.H.
Commissioner of Health
State of Oklahoma
VIII
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SPONSORS
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Humboldt State University Sea Grant Program
Office of Academic Affairs
California State University, Humboldt
Arcata, California 95521
Midcontinent Environmental Center Association
Box 201
Tulsa, Oklahoma 74102
Oklahoma Environmental Information and Media Center
East Central State College
Ada, Oklahoma 74820
Robert S. Kerr Environmental Research Laboratory
Environmental Protection Agency
Box 1198
Ada, Oklahoma 74820
Fish Farming Experimental Station
Bureau of Sport Fisheries and Wildlife
Box 860
Stuttgart, Arkansas 72160
University of Oklahoma College of Health and
Allied Health Professions
University Health Sciences Center
P.O. Box 26901
Oklahoma City, Oklahoma 73190
IX
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SPEAKERS
George H. Allen, Ph.D..
School of Natural Resources
Calif. State Univ., Humboldt
Arcata, California 95521
Larry 0. Bagnail
Agricultural Engineer
University of Florida
Frazier Rogers Hall
Gainesville, Florida 32611
Thomas G. Bahr, Director
Institute of Water Research
Michigan State University
East Lansing, Michigan 48824
Nancy Bakaitis
Asst. Prof, of Chemistry
Natural Science Division
Findlay College
Findlay, Ohio 45840
Frank L. Bryan, Ph.D.
Foodborne Disease Activity
Health Agencies Branch
Center for Disease Control
Atlanta, Georgia 30333
R. LeRoy Carpenter, M.D., M.P.H.
State Commissioner of Health
State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
James Clinton
Project Biologist
Brookhaven Natl. Laboratory
Building 318
Upton, New York 11973
Mark S. Coletnan, Director
Water Quality Monitoring and
Research Division
Water Quality Services
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Ronald W. Crites
Metcalf & Eddy, Inc.
1029 Corporation Way
Palo Alto, California 94303
Donald L. Day
College of Agriculture
and Engineering
University of Illinois
Urbana, Illinois 61801
W. R. Dinges, R.S.
Field Activities
Div. of Wastewater Technology
& Surveillance
Texas State Dept. of Health
1100 West 49th
Austin, Texas 78756
Dr. B. Hepher, Director
Agricultural Research
Organization
Fish & Aquaculture Research
Station
Dor, Israel
E. W. Houser
Manager-Engineer
Santee County Water District
P.O. Box 70
Santee, California 92071
John E. Huguenin
Research Associate
Woods Hole Oceanographic Inst.
Woods Hole, Mass. 02543
Lewis H. Irving, Ph.D.
Department of Sociology
Central State University
Edmond, Oklahoma 73034
William B. Kerfoot
Woods Hole Oceanographic Inst,
Woods Hole, Mass. 02543
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SPEAKERS (Continued)
Larry D. King
Agriculture Resource Dev. Branch
Tennessee Valley Authority
Muscle Shoals, Alabama 35660
Dr. Richard J. Krejsa
Supervisor Fifth District
San Luis Obispo County
Room 220 - Courthouse Annex
San Luis Obispo, Calif. 93401
Harry Manges
Associate Professor
Agricultural Engineering
Kansas State University
Manhattan, Kansas 66506
Dr."Karl Schurr
Biology Department
Bowling Green State Univ.
Bowling Green, Ohio 43403
John R. Sheaffer, Ph.D.
President
Bauer, Sheaffer & Lear, Inc.
20 North Wacker Drive, Suite 2510
Chicago, Illinois 60606
Dr. Geoffrey Stanford
School of Public Health
Holcombe Boulevard
Houston, Texas 77025
Richard H. Sullivan
Asst. Executive Director
American Public Works Assn.
1313 East 60th Street
Chicago, Illinois 60637
Jeffrey C. Sutherland, Ph.D.
Williams & Works
250 Michigan Street, N.E.
Grand Rapids, Michigan 49503
Rafael Tuburan
School of Public Health
Holcombe Boulevard
Houston, Texas 77025
William R. Walker
Virginia Polytechnic Inst.
225 Norris Hall
Virginia Water Research Center
Blackburg, Virginia 24061
Jack N. Walter
Dept. of Agricultural
Engineering
Penn State University
University Park, Pa. 16802
XI
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PARTI INTRODUCTORY SESSION
CONFERENCE CHAIRMAN
R. LeROY CARPENTER, M.D., M.P.H.
COMMISSIONER OF HEALTH
OKLAHOMA STATE DEPARTMENT OF HEALTH
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REVIEW OF AMERICAN PUBLIC WORKS ASSOCIATION
STUDY OF FACILITIES UTILIZING LAND APPLICATION OF WASTEWATER
Richard H. Sullivan
Assistant Executive Director
American Public Works Association
Presented March 6, 1974 at a
Conference on the Use of Wastewater in the
Production of Food and Fiber
Oklahoma City, Oklahoma
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REVIEW OF AMERICAN PUBLIC WORKS ASSOCIATION
STUDY OF FACILITIES UTILIZING LAND APPLICATION OF WASTEWATER
Richard H. Sullivan, Assistant Executive Director
American Public Works Association
The American Public Works Association, in 1972, conducted an on-site field survey or
approximately 100 facilities in all climatic zones where land application of community of
industrial wastewaters are being applied to the land, as contrasted to the conventional
method of treating such wastes and discharging them into receiving waters. The project was
sponsored by the U.S. Environmental Protection Agency under Contract No. 68-01-0732.
The report, entitled Survey of Facilities Using Land Application ofWastewater, is available
from the Government Printing Office as EPA-430/9-73-006 at a price of S6.80.
Additional data were gathered from many existing land application facilities across the
country by means of a mail survey addressed to responsible officials. Another survey was
carried out to ascertain the nature and extent of state health and water pollution control
regulations governing the use and control of land application systems. To augment informa-
tion on U.S. practices, a survey was made of experiences gained in many foreign countries.
In addition, an extensive bibliography was compiled of literature on all pertinent phases of
land application practices. The bibliography has been combined with that of three other
studies and will be published separately. It will have abstracts of almost 800 articles.
The facilities surveyed were relatively large with long established operations in order
that as much operating experiences as possible could be obtained. The surveyed application
facilities utilizing community wastes were predominantly located in the western and south-
western portions of the United States, while industrial facilities were generally sited in the
northeastern section because this is where the majority of such installations are in service.
Table 1, Summary of Facilities Using Land Application of Wastewater, lists pertinent
information concerning the sites for which information was obtained for the states of
Kansas, New Mexico, Oklahoma and Texas. Two sites were found in Kansas, nine in New
Mexico, three in Oklahoma, and 50 in Texas. Texas and California were the two states with
the most facilities. However, in all of the southwest, only two industrial facilities were
•found and both were in Texas.
Land application of effluent involves many means of accomplishing a variety of objec-
tives. Among the more important objectives, the following were found:
1. to provide supplemental irrigation water;
2. to give economical alternative solutions for treating wastes and discharging them
into receiving waters, without causing degradation of rivers, lakes and coastal waters
and;
3. to overcome unavailability of suitable receiving waters and eliminate excessive costs
of long outfall lines to reach suitable points of disposal into surface water sources.
Among the major means of accomplishing land application of wastewaters are:
1. irrigation of land areas by spraying, with high-pressure or low-pressure devices, of
either stationary or movable types of distribution systems;
2. ridge and furrow irrigation systems;
3. use of overland flow or flooding methods; and
4. use of infiltration lagoon or evaporation ponds.
Although facilities of all types were surveyed, the report is primarily concerned with
irrigation-type facilities for supplying supplemental water to crop areas, forest areas and
unharvested soil cover acreages. The other types are not as widely used, inasmuch as many
factors such as climate or soil conditions have an adverse impact on these means of land
application.
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Table 1. Summary of Facilities Using Land Application of Wastewater
State
Kansas
Scott City
Sublette
New Mexico
Almagordo
Clovis
Raton
Roswell
Santa Fe
Lovington
Los Alamos Co.
Raton
Silver City
Oklahoma
Duncan
Boise City
Hollis
Texas
Abilene
Dumas
Kings ville
La Mesa
Midland
Monohans
San Angelo
Uvalde
Coleman
Comanche
Cotulla
Dalhart
Denver City
Elsa
Goldthwaite
Idalou
Morton
Munday
Rails
Raymond ville
San Saba
Seagraves
Van Horn
Winters
Campbell Soup,
Paris
Anson
Azle
Crane
Crosbyton
Eldorado
Freer
Friona
Armour Food,
Hereford
Hondo
McLean
Information
Questionnaire
Questionnaire
Visited
Visited
Visited
Visited
Visited
Questionnaire
Verified
Verified
Verified
Visited
Questionnaire
Verified
Visited
Visited
Visited
Visited
Visited
Visited
Visited
Visited
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Verified
Verified
Verified
Verified
Verified
Verified
Verified
Verified
Verified
Verified
Population
4,325
1,332
25,000
28,000
2,300
40,000
45,000
10,000
20,000
1,980
100,000
9,770
30,000
1 1 ,400
62,000
8,000
64,000
9,000
5,608
5,000
3,900
5,700
4,200
5,000
1,700
1,800
3,760
1,700
2,100
7,986
2,555
2,500
3,000
2,907
Industry
Industry
•TM**^*
Flow - mgd
0.432
0.13
2.5
3.5
0.5
2-3
5.3
0.5
0.36
0.4
0.5
2.5
0.001
0.3
9.0
1.0
3.0
0.6
4.3
0.8
5.0
0.9
0.3
0.4
0.165
0.64
0.15
0.18
0.2
0.1
0.87
0.126
0.2
0.15
0.154
3.1
0.4
0.25
0.2
0.125
1.
0.25
<1
1.15
0.4
0.1
Crops Area
Rice
Alfalfa, corn, oats, sorghum
Irrigated
Acres
25
40
260
Milo, alfalfa, corn, millet, wheat 1 ,193
Alfalfa
Alfalfa, barley, corn, cotton
Alfalfa, apples
Wheat, Bermuda grass
Cotton, maize, Bermuda grass
Wheat, maize
Maize
Bermuda grass, alfalfa, milo,
cotton
Barley, milo, rye, oats, fescue,
alfalfa, Bermuda grass
Maize, oats
Hay
Cotton
Feed, cotton
Cotton
Cotton
Grain
200
770
740
160
180
40
2,019
585
606
192
1,000
40
740
150
106
12
12
200
4.5
100
10
60
20
160
80
160
10
10
500
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Table 1 (Continued)
Odessa Verified 1.075
Ozona Verified 0.3
Petersburg Verified 0.2
Quitague Verified 0.06
Rotan Verified 0.11
Sabinal Verified
Santa Ana Verified
Seminole Verified 0.9
Slaton Verified 0.37
Sonora Verified 0.3
Stanton Verified 12
Stratford Verified 0.01
Sundown Verified 0.16
Sweet water Verified 0.75
Summary of Land Application Sites (Non-Military)
For Which Information Was Obtained
Total Total Total
Visited Questionnaires Verified Total
United States 89 122 136 347
Kansas — 1 12
New Mexico 51 39
Oklahoma 11 13
Texas 8 17 25 50
Irrigation-type facilities were found to be broadly used under a wide variety of climate
and soil conditions, with various degrees of prior treatment of the applied wastewater and
various types of ground cover utilized.
Each method of application has inherent advantages and disadvantages which must be
evaluated for their feasibility and effectiveness.
The land application of waste waters has been practiced extensively in many parts of the
world for many years with varying degrees of control and success.
degrees of control and success.
As knowledge of wastewater treatment processes improved, and the possibility of con-
fining in a relatively small area the entire process needed to obtain a "treated" effluent for
disposal into surface water sources, land application in the united States was relegated in
most states to being an undesirable and unacceptable process.
New concerns about preserving the quality and reuse of the nation's water resources
have resulted in a reawakening of interest in land application as a viable alternative to
conventional wastewater treatment and disposal into receiving waters. Increasing volumes of
sewage and industrial wastes, growing complexity of such raw wastes, and mounting needs
for water to serve growing urban and industrial processing needs, have created doubts about
the ability of receiving waters to assimilate effluents which do not meet high-quality stan-
dards. In addition, progressive evidences of eutrophication of non-flowing receiving waters
have focused attention on the need to eliminate the presence of nutrients in wastewater
effluents. Further, the presence of toxic trace elements in effluents is considered a threat to
the safety of waters receiving all but highly purified waste discharges. Thus, advanced
treatment methods have been developed and utilized to avoid discharge of such objection-
able components.
Inasmuch as land application appears to offer comparable or superior degrees of treat-
ment by augmenting waste treatment with the "natural" purification offered by soil con-
-------
tact, land application is again being considered as one of the acceptable means of achieving
full treatment of waste waters.
However, a most important factor of the current land application concept is that it
must be limited to the use of treated wastes. Generally, effluents are being conventionally
treated to almost meet secondary treatment quality criteria. In at least three observed
facilities, applied effluents have received tertiary treatment, to the point where the effluent
would fully meet the generally prescribed, as well as proposed, criteria for discharge to
receiving waters. Thus, land application is being used to give a degree of advanced waste
treatment, including high degrees of nutrient and bacterial removal. In this context, land
application can be viewed as an alternative to physical-chemical processes and other
methods of ultra-treatment which are designed to achieve a "pure" effluent.
Economics of construction cost, operating costs, energy requirements, and efficiencies
of performance of land application systems must be balanced with the ability to acquire the
right to apply wastewater upon the required land areas. The cost of advanced waste treat-
ment by conventional means must be weighed in the light of the cost and complexities of
land application systems.
Two informative reports were published on the subject of land application in 1972.
Green Lands - Clean Streams, a report by Temple University Center for the Study of
Federalism, is a frankly written advocacy of the land application of wastewaters and sludges.
Wastewater Management by Disposal on the Land, by the U.S. Corps of Engineers, is a
thorough review of the physical, chemical and biological interactions involved in land appli-
cation.
The firm of Metcalf and Eddy, Engineers, has prepared a companion report for USEPA,
concerned with engineering considerations of land application systems. These three reports,
together with the report on the study conducted by APWA, should be considered in evaluat-
ing land application systems, because they deal with somewhat different aspects of the
common problem. The APWA study has made no special effort to examine the specific
aspects covered in detail in the other reports. Rather, it is concerned with reporting upon
the policies, practices and performances of a representative group of the relatively larger
systems within the United States; policies, or lack of policies, of state regulatory agencies;
and the experience with land application in some foreign installations.
Systems which were under construction, such as Muskegon County, Michigan, and
several major domestic and industrial systems which were intimately known to Metcalf and
Eddy project personnel were not investigated for this report. However, Metcalf and Eddy
has supplied copies of their field interviews at such sites to APWA for evaluation.
The following highlights from the field surveys are presented in order that a composite
picture of observed facilities might be obtained:
1. Communities generally use their land application system on a continuous basis.
Food processing plants, the predominant industrial users of the system, generally
practice discharge to land systems for three to eight months per year.
2. Ground cover utilized for municipal systems is divided between grass and crops.
Industries generally use grass cover.
3. Land application systems are generally used on a daily basis, seven days per week.
4. Application rates for crop irrigation are very low in terms of inches of water per
week. Two inches or less was commonly used. (Note: Two inches per week equals
54,300 gallons per acre per week.)
5. Many types of soils were used; although sand, loam and silt were the most common
classification given. Two systems using application over many feet of sand were
applying up to eight inches per week, and one system on clay was applying only 0.1
inch per day.
6. Most operating agencies, municipal and industrial, are planning to either expand or
continue their land application installations. The few examples of systems which
-------
had been abandoned were due to either the desire to make a higher use of the land,
or because of reported overloading and poor operation of the land application
facilities.
7. Industries surveyed generally treat their total waste flow by land application. Prac-
tices of municipalities varied from less than 25 percent to all waste waters produced.
8. Treatment greater than primary is generally provided by municipalities prior to land
application, often times accompanied by lagooning. Industrial systems often treated
their process wastes by screening only.
9. Spray irrigation is the most frequently used (57 facilities) method of application,
although most municipalities use more than one method. Ridge and furrow irriga-
tion is used at 23 facilities and flooding irrigation by 34 systems. Industry generally
used spray irrigation.
10. Land use zoning for land application sites is predominantly classified as farming,
with some residential zoning in contiguous areas.
11. Wastewater generally is transported to the application site by pressure lines, al-
though a number of municipalities are able to utilize ditches or gravity flow pipe
lines.
12. Many community land application facilities have been in use for several years -
more than half for over 15 years. Industrial systems are relatively more recent.
13. Renovated wastewater is seldom collected by under-drains; rather, evaporation,
plant transpiration, and groundwater recharge take up the flow.
14. Land application facilities generally do not make appreciable efforts to preclude
public access. Residences are frequently located adjacent to the land application
sites. No special effort is made to .seclude land application areas from recreational
facilities and from those who use these leisure sites.
15. Monitoring of groundwater quality, soil uptake of contaminants, crop uptake of
wastewater components, and surface water impacts is not carried out with any
consistency.
Among the most "advanced" facilities which we reviewed were the Tallahassee system
and the systems at Colorado Springs, Colorado, and the University of Pennsylvania at State
College.
The largest agriculture venture was found to be at Tula Hidalgo where the wastes of
Mexico City, D.F., are applied to the land to supplement the natural irrigation waters of the
area. Some 115,620 acres are irrigated and in 1971-72, 1,624,424 U.S. tons of crops were
grown. Table 2, Summary of Agriculture production, 1971-72, Tula Hidalgo, lists the 31
major crops which are grown.
Information which was received on crop research conducted at Debrecen, Hungary, is
also included, in our report. A comparison in yields obtained with the use of treated waste-
water as contrasted with normal irrigation practices is given in Table 3, Comparison of Crop
Yield, Hungary.
A major concern has also been the boron concentration of wastewater and the relative
tolerance of plants to boron. Table 4, Units of Boron in Irrigation Waters for Agriculture
Products with Different Grades of Tolerance, was developed by Mexican Agriculture offi-
cials. The data contained in the report allows ready identification of where a wide variety of
crops have been raised and an indication as to the physical conditions which exist at the site.
In summary, land application of treated municipal effluent and industrial wastes should
be a viable alternative to conventional disposal or advanced tertiary treatment techniques in
many areas of the country. Full evaluation of application should be made as planning of
new or upgraded wastewater facilities is undertaken.
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Table 2. Summary of Agriculture Production
1971-72, Tula Hidalgo
Crop
Alfalfa Verde
A jo
Arvcjon
Avcna Verde
Calabacita
Cebada Grano
Ccbada Pago
Cebolhi
Cila/itro (seniilla)
Co!
Chichnro
Chiles Verde
Florcs
Fiijol Grano
Fiijol Ejotc
Espinaca
Frutalcs
Givasol
Haba
Jitoniate
Lechuga
Mai?, Grano
Maiz Rastrojo
Maiz Verde
Nabo Forraje
Melon
Pepino
Pradera
Tomatc
Trigo Grano
Sandia
Crop
Alfalfa
Garlic
Green Oals
Squash (small)
Barley Grain
Barley (forage)
Onioi)
Parsley Seed
Cabbage
Peas
Green Hot Peppers
Flowers
Navy Beans
Am. String Beans
Spinach
Fruit Trees
Sunflower
Lima Beans
Am, Tomato
Lettuce
Corn (kernels)
Corn (forage)
Corn (sweet)
Forage Turnips
Melon
Cucumber
Meadow Grass
Tomato
Wheat Grain
Watermellon
Hectares
12,396.40
94.50
12.89
2,998.75
674.33
1,865.43
23.79
3.53
27.95
1.00
768.80
10.41
Metric Tons
1,181,376.920
258.456
20.820
54,426.714
7,282.764
3,645.410
4,059.874
168.909
4.589
501.843
7.900
8,231.350
1,259.02
58.30
0.82
25.08
37.19
95.84
1,554.65
74.47
17,053.60
101.20
112.37
1.00
34.74
12.80
216.90
7,293.79
0.40
46,809.95
Acres
115,620.65
1,563.870
151.580
9.020
213.180
230.578
1,990.070
49,437.870
1,457.764
70,260.525
65,179.023
7,084.000
1,011.330
7.100
166.752
2,080.000
2,051.706
13,865.494
3.960
1,476,749.37)
U.S. Tons
1,624,424.30
Note: 1 metric ton =1.1 (U.S.) tons
1 (U.S.) ton = 0.907 metric tons
\ hectare =2.47 acres
Note: The crop hectares listed arc more than the hectares of land available since a second
Crop in some instances lias been produced on the same land.
-------
Table 3. Comparison of Crop Yield, Hungary
Sugar beets
Dry grain maize
Fodder maize
Alfalfa
Sunflower seed
Industrial potatoes
Debrecen
Station
(Wastewater)
363.24 q/ha
58.5 q/ha
346. 19 q/ha
99.25 q/ha
14.87 q/ha
11 9. 8 q/ha
Gyozelen
Farm
(Control)
365.0 q/ha
22.49 q/ha
2 17/2 5 q/ha
46/58 q/ha
4. 17 q/ha
59.3 q/ha
Table 4. Units of Boron in Irrigation Waters for Agriculture
Products with Different Grades of Tolerance
Tolerant
4 ppm
Asparagus
Palm Trees (Phoenix
Canariensis)
Date (Phoenix Tytiferia)
Sugar Beets
Beet
Bctabel
Alfalfa
Giadiota
Bean
Onion
White Radish
Cabbage
Lettuce
Carrot
Semi-tolerant
2 ppm
Sunflower
Potato
Cotton
Tomato
Sweet pea
Radish
Olive
Barley
Wheat
Corn
Oats
Calabash
Sweet Potato
Lima or Kidney Beans
2 ppm
1 ppm
Sensitive
1 ppm
Mexican Oak
Black Oak, Persian
or English
Tuberous Sunflower
White Beans
American Elm
Plum
Pear
Apple
Grape
Fig
Nispero
Cherry
Peach
Apricot
Blackberry
Orange
Avocado
Grapefruit
Lemon
0.3 ppm
Source: Analysis of the Black Waters of the Cuenca of the Valley of Mexico and tin-
Region of lil Mczquital, Hidalgo-Bulletin 2 Hydraulic Commission of the
Cuenca of the Valley of Mexico, Mexico, D.I-'., March 1965
8
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WASTEWATER UTILIZATION
IN
INTEGRATED AQUACULTURE AND AGRICULTURE SYSTEMS
by
B. Hepher and G. L. Schroeder*
INTRODUCTION
Israel approaches today a hundred percent use of its water resources.
Out of an estimated potential 2.0 X 10 J m3 of water, 1.7 X 109 m3 are
being already used. In these conditions, it is obvious that recycling
of wastewater becomes mandatory. The problem, while extreme in Is-
rael, is experienced in many countries.
A semi-arid country, such as Israel, has the highest quantitative de-
mand for irrigation water in agriculture. On the other hand, the
qualitative criteria for this water is low. These two considerations
make agriculture the prime potential sector for the reuse of waste-
water. However, the following limitations restrict this reuse and
lower its efficiency:
a) Irrigation is restricted to the dry season, the summer. In win-
ter, there is little use for the wastewater in irrigation. According
to a recent study1, about 5.2 X 10s m3 of potentially useful waste-
water are produced in Israel per day. Of this, in the peak irrigation
season 1.7 X 10* m3, i.e., about 32% are used. However, when calcu-
lating on a yearly basis, out of 1.9 X 10** m3 wastewater produced,
only 3.7 X 107, or less than 20% are used. The difference is produced
mainly in the winter and disposed of, often in a manner that produces
ecological disruption.
b) Irrigation with treated waste effluent is limited by sanitary con-
siderations. Some crops cannot be irrigated by this water because of
its residual pathogenic organisms.
c) High salt concentrations make some effluents not suitable for ir-
rigation. The chloride concentration in Haifa sewage, for example,
is 480 mg/1 (Miron2). This limits the agricultural applications to
low volumes and a small number of crops.
d) Areas exist where the agricultural demands for water are less
than the volumes of treated waste effluent available.
It seems to us that the solution to handling all of these problems en-
countered in profitably using waste effluent lies in a system which
integrates waste treatment with aquaculture and agriculture. The re-
sult is a flow of waste from treatment plant through fish ponds to
irrigated fields.
*Fish and Aquaculture Research Station, Dor,
D. N. Hof HaCarmel, Israel
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BENEFIT OF FISH PONDS IN WASTEWATER UTILIZATION
Fish culture can accept wider variations in environmental conditions
than can agriculture. Fresh water fish can adapt to the high salini-
ties often encountered in waste effluent. The growth of carp, for
example, is not inhibited even at salt concentrations as high as
2000 ppm chloride. Tilapia and trout can grow in sea water. The per-
missible salinity in irrigation water is considered to be 400 ppm
chloride, in Israel. Soirquality in fish culture is also less of a
limiting factor than it is in agriculture. In Israel, ponds are often
constructed on swampy soil and on sand. Water loss by seepage from
sand ponds decreases rapidly because of clogging of soil interstices
by organic matter. The use of wastewater in fish ponds can come in
addition to, or in place of, agricultural use.
It is clear that only impoundment and storage of wastewater effluents
can be the answer to the seasonal variations and daily fluctuations in
the demand for irrigation water. This impoundment is usually expen-
sive. However, utilizing the impoundments for fish culture cannot
only justify the holding expense, but also produce a protein rich food
for human consumption bringing, an overall profit. It is interesting
that the new methods of superintensive aquaculture being developed in
Israel are directly applicable to a system integrating usilization of
waste effluent and aquaculture. This approach basically combines
densely stocked ponds with the introduction of air. The aeration acts
as a safeguard against deoxygenation and fish kill. This aeration
also can satisfy the uptake of oxygen by the decomposition of the ad-
ded organic matter. At the same time this organic matter acts as the
basic link in the chain of natural foods on which the fish can graze.
The yield of a fish pond depends on the stocking rate of the pond
(number of fish per unit area) and the pond management, both of these
factors being tightly linked. If the stocking rate alone is increased
the amount of natural food per fish will decrease. Fish growth will
then decrease or cease entirely and only a small yield or no yield at
all will be obtained. However, if parallel to increasing the stock-
ing rate more food is provided, the growth rate is maintained and the
pond's yield will be directly proportional to the density of stocking
(figure 1). Because the costs of construction and operation of a pond
are largely fixed, regardless of the amount of fish stocked, it is
clear that the higher the rate of stocking, the greater will be the
net profit. The required increase in food to maintain this higher
fish density can be achieved in several ways: increasing the product-
ion of natural food through the use of chemical and organic fertili-
zer, in our case waste effluent; better utilization of existing nat-
ural foods through polyculture, i.e., the introduction of carefully
selected species of fish, each feeding on a different natural food;
and, supplementing the natural food with added fish feed.
10
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Supplemental feed is often the largest single operating expense in
fish farming. A way should be found to reduce the need for supplemen-
tal feed, while at the same time maintaining the high fish yield.
This can be achieved by increasing the amount of natural food in the
pond. Abundant production of zooplankton in aerated sewage ponds is
regularly observed3. Benthic fauna are also increased. Wirshubsky
and Elchuness^ found a 30-fold increase in the production of chirono-
mides in ponds receiving organic wastes as compared to non-fertilized
ponds. This fauna represents a source of valuable protein readily ac-
cepted by fish. We have studied the effect of the introduction of or-
ganic matter at high rates on the production of natural foods with
fish. Liquid cow shed manure was added to non-aerated ponds with and
without fish, at rates up to 100 kg BODs per hectare every two weeks.
During winter months (November - February; pond temperature
15°C), we observed standing stocks of fauna as follows:
no fish no fish fish fish
pond type: manured no manure manured no manure
zooplankton 3.3-42.4 <0.055 0.34-1.3 <0.055 gm dry/m3
chironomides 79-215 1-7 1-4 0-2 100's/m3
The zooplankton reported are those retained on 150u screen.
The effects of the added organic waste on increasing the standing
stocks of natural food are clear. Comparing the data from ponds
with and without fish clearly shows the effect of fish grazing on
the additional natural food resulting from the added waste.
77
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feed; (2) fertiliser,
feed; (4) fertilizer,
no feed
poly-
(3) fertilizer, cereal feed; (4) fertilizer,
culture; (5) fertilizer, protein-rich feed;
(6) fertilizer, protein-rich feed, demand feeders;
(7) fertilizer, protein-rich feed, polyculture;
(8) fertilizer, protein-rich feed, polyculture,
g
20
1
•<
6-
O
a
OT
55
O
Q
Yield to cover fixed costs
1 Yield to cover investment
5 10
STOCKING RATE (THOUSANDS FSR HECTARE)
Figure 1. Effect of Stocking Rate on Yield in Fish Ponds
12
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WATER IMPROVEMENT BY PONDS
The sanitary limits placed on irrigation water can be largely over-
come by holding the water in fish ponds. A pond, by its very nature,
purifies the wastewater by exposure to the high ozygen ^tension and pH
which are produced by phytoplankton. Kisalt and Ilzohoferb demonstra-
ted that the reduction in total number of bacteria in sewage in ponds
reaches 99.6%, compared with 90% reduction in activated sludge method,
and 89% in trickling filters. We found that the addition of fish to
the ponds receiving biological wastes in all instances further im-
proves the quality and increases the capacity of the pond for waste
treatment. In the experiments mentioned above, of adding high rates
of liquid manure to ponds with and without fish, we observed the
following results:
pond type: no fish, manured fish;manured fish; no manure
bacteria 17 - 27 1.6 - 6.7 0.7 - 4.3
(1000/ml)
pH (0900 hrs) 7.9 - 8.3 8.3 - 8.9 8.6 - 8.7
D.O. (ppm) 0.7 - 9.5 9.0 - 15.9 10.0 - 13.8
temperature 9-15 9-15 9-15
, 0900 hrs)
Bacteria were counted as colonies grown in 0.5% yeast extract agar
as described in Standard Methods^.
One factor which can be attributed to the lower bacteria counts ob-
served in ponds containing fish is the consistently high pH developed
in these ponds. Oswald7 reports an increased rate of disinfection
from coliform with increasing pH.
A further benefit of increased pH is an increase in the efficiency
with which ponds act as nutrient trap by fixing phosphorous in insol-
uble compounds and releasing nitrogen to the atmosphere (Hepher8;
Oswald, ibid). This higher pH appears to be due to the lower C02
concentrations observed in the ponds stocked with fish. The lower
C02, in turn, probably results from lower standing stocks of zoo-
plankton and then bacteria in these ponds, and hence lower respira-
tion volumes.
PROBLEMS WITH EFFLUENTS IN FISH PONDS
Two major factors affect the possibility of using fish in an integra-
ted waste effluent-aquaculture system: dissolved oxygen concentrations
13
-------
in the pond water; and, the presence of piosons, especially deter-
gents, in the waste effluent.
It is clear that the D.O. must be maintained above the lethal level
for the species of fish stocked. Even a single case of anaerobic con-
ditions for several hours will result in the loss of the season's en-
tire fish crop. We find that we are able to predict the rate of D.O.
depletion in the water by taking into account the BOD of the waste,
the pond temperature, and the naturally occurring diurnal D.O. cycle
in the pond water. It is clear that in any case these parameters
must be carefully monitored. However, having the capacity of aeration
as we mentioned above, greatly reduces the hazards of fish kill by
suffocation.
Industrial waste may contain lethal concentrations of metallic poisons
and must be considered separately. A much more common problem is the
piosonous effect of detergents on fish. Hard detergents can pass
through a treatment plant with no appreciable reduction in concentra-
tion and kill fish. We have worked with waste water from the city of
Haifa. This waste often contained about 17 ppm ABS, while the lethal
ABS concentration for carp is 10 ppm. In this work we found that even
sublethal concentrations reduced the growth rate of the fish. A
natural degradation of one ppm ABS per week was observed in the open
fish ponds. Based on this our solution was to age the waste in ponds
prior to stocking with fish, and then replace daily evaporation and
seepage loss by fresh waste. This amounted to an addition of about
100 m'/hectare/day. The resulting high delution of fresh, by aged,
waste made the system operational. With the change to biodegradable
soft detergents this problem is greatly reduced.
In considering the problem of integrating aquaculture, agriculture,
and waste effluent treatment, we should look at the system as an eco-
logical entity. Fish fill one of the important ecological niches in
this system. By so filling this niche we make the system more balan-
ced, more efficient, and more beneficial for man and his environment.
-------
REFERENCES
1. E.E.T. Company. Accumulation, Treatment, and Utilization of
Sewage in Israel. 1971
2. Miron, A. Salt Sources in Haifa Sewage. Tahal, 1964, 26p.
3. Pillay, T. Culture of Fish Food Organisms. FAO Fish Culture
Bulletin. 2(2):6, January 1970
4. Wirshubsky, A., and M. Elchuness. A Preliminary Report on the
Breeding of CMronomides in Concrete Ponds. Bamidgeh
£(1/2):1-5, 1952.
5. Kisalt, A., and H. Ilzhoffer. Die Reinigung von Abwasser in
Fischteichen. Arch. Hyg. Berl 118^:1-66, 1937
6. Farber, L. Standard Methods for the Examination of Water and
Wastewater. New York, American Public Health Assoc., 1962,
478-493 p.
7. Oswald, W. Complete Waste Treatment in Ponds. 6th Inter-
national Water Pollution Research. New York, Pergamon Press,
1972, B/3/6/1.
75
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PART 2 TECHNICAL RESTRAINTS
SESSION CHAIRMAN
LELANDJ. McCABE, M.P.H., B.S.C.E.
CHIEF, CRITERIA DEVELOPMENT BRANCH
WATER SUPPL Y RESEARCH LABORA TORY
NATIONAL ENVIRONMENTAL RESEARCH CENTER
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO
-------
DISEASES TRANSMITTED BY FOODS
CONTAMINATED BY WASTEWATER
Frank L. Bryan, Ph.D.,M.P.H.
In a world of limited resources and expanding human populations, an
ample and safe food supply is vital for populations to thrive. New
food sources and improvements in agricultural and aquacultural methods
must be investigated and utilized; wastes generated by increasing
concentrations of people must be disposed of adequately. Recycling
wastewater for watering and nourishing food crops or for growing fish
contributes to both food production and waste disposal. But when waste-
water is used to irrigate crops or to provide water in aquaculture,
appropriate precautions must be taken to prevent the diseases that might
otherwise be transmitted by wastewater-contaminated foods.
Foods can become contaminated during production either on farms or in
watercourses, during processing in food processing plants, and during
preparation in food service establishments and homes. The point at
which contamination occurs will depend on the natural sources of a
pathogen and on the opportunities for transfer at each stage of the
food chain. Factors that contribute to reported foodborne disease
outbreaks are reviewed by Bryan1.
Many of the pathogenic organisms that infect man reach him by being
conveyed by more than one vehicle. For example, eggs of some parasitic
organisms can appear in feces of infected persons, reach water in which
they hatch into a form that infects a vector (as a snail), and, after a
period of development metamorphaze into a free-swimming form which pene-
trates tissues of fish or water vegetables. Diseases caused by such
parasites and features of their transmission are listed in Table 1.
Few of these parasites are found in the United States, but they are
prevalent in some other regions of the world.
Other parasites, such as those that cause hookworm infection, schisto-
somiasis, and leptospirosis, penetrate human skin in their infective
stage and may be acquired by agricultural or aquacultural workers who
work in wastewater-contaminated fields or ponds (World Health Organiza-
tion2) .
Most of the organisms that are conveyed by wastewater-contaminated foods
have less complicated transmission cycles. The organisms that have
potential of transmission by such a route, and the diseases they cause,
are listed in Table 2.
76
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The following circumstances must occur for persons who ingest wastewater-
contaminated foods to become ill:
(1) The infectious agent must be present in citizens of a community
or in animals on farms, or toxic agents must be used for indus-
trial or agricultural purposes; and wastes from these sources
must reach sewerage or drainage systems.
(2) The agents must survive and pass through all wastewater treatment
processes to which they are exposed.
(3) The waste-treatment effluent or watercourse receiving the
effluent must be used as irrigation water for crops or as a grow-
ing environment for fish or watercrops or for washing or freshen-
ing harvested foods. Thus, the agents must survive in the
receiving watercourse.
(4) The agents must survive in the soil in which irrigated foods are
grown.
(5) The agents must contaminate a food product.
(6) Then one of the following events must occur:
(a) The agents must be present on the contaminated food in
sufficient numbers to survive storage and preparation and
still cause illness.
(b) Bacteria on foods in insufficient numbers to cause illness
must multiply and reach levels that are necessary to cause
illness.
(c) Bacteria, and perhaps other organisms, enter food preparation
areas on raw foods, where they may be transferred to workers'
hands or to equipment surfaces which if inadequately washed
will then contaminate other foods that they subsequently
touch.
(7) Sufficient quantities of the contaminated food that contain
enough of the agent to exceed a person's susceptibility threshold
must be ingested. Ingestion of foods contaminated to this level
may result in sporadic cases of illness as well as epidemics.
When insufficient numbers of pathogens to cause illness are
ingested, the infected individuals may become carriers and
subsequently contaminate other foods that they touch.
Each step of this chain of events necessary for wastewater to contribute
to foodborne outbreaks of human disease is reviewed based on information
from engineering and medical literature.
PATHOGENS IN SEWAGE
Numerous investigators have isolated pathogens from sewage. These
investigations have been reviewed by Rudolfs et al. 3 *, Greenberg and
Dean5, Kollins6, and Grabow7. Animal wastes contain many of the
same pathogens as well as other pathogens.
77
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SURVIVAL IN WASTE-TREATMENT PROCESSES
Enteric pathogens survive some stages and sometimes the entire process
of wastewater treatment. Table 3 highlights the results of some typical
investigations of the effect of various wastewater-treatment processes
in removing or killing pathogens. Primary sedimentation usually removes
less than 50 percent of coliform and pathogenic bacteria from sewage;
it is relatively ineffective in removing viruses and protozoa. Acti-
vated sludge or trickling filter processes followed by secondary sedi-
mentation usually removes over 90 percent of coliform or pathogenic
bacteria remaining after primary sedimentation. Viruses can be signi-
ficantly reduced by activated sludge but not by trickling filter
processes. Sand filtration is required to remove amoebic cysts and
Ascarls eggs. Anaerobic digestion reduces 90 percent of pathogenic
bacteria from sludge but is less effective for destruction of Ascaris
eggs. Hepatitis viruses, Endamoeba histolytica cysts, and tapeworm
eggs withstand the chlorination treatment generally applied to waste-
treatment effluent. Thus, many waste-treatment processes remove or kill
90 percent or more of the pathogens that are present in influent sewage,
but some still remain in the effluent. If a million pathogens, for
example, are present in influent sewage before exposure to processes
which remove 90 percent of them, 100,000 survive; in the case of
99 percent destruction, 10,000 survive. Kampelmacher and van Noorle
Janssen22 found that 1010 salmonella entered a trickling filter
secondary treatment plant each hour and that 109 left the plant in the
effluent each hour.
SURVIVAL IN RECEIVING WATERCOURSES AND USE OF WASTEWATER FOR IRRIGATION
Those organisms that survive wastewater treatment must also survive in
receiving waters. Such survival has been reviewed by Rudolfs3 "*,
Dunlop et al.eo, Clarke et al.81, Rollins6, and Grabow7. Factors in-
fluencing survival in water include temperature, amount of light, flow
rate, presence of oxygen, pH, dilution, amount of dissolved material,
and types of organisms in the water.
Irrigation water may be sprayed over crops, flow through channels in
fields and seep to roots, or be flooded over the field. The numbers of
pathogens applied to soil during irrigation can be of such magnitude
that outbreaks can result. During an epidemiologic investigation,
RenteIn and Hinman176 found that sewage plant effluent used to irrigate
a field was channeled by gopher holes to a well pit and entered a
community water supply through a defective well casing.
SURVIVAL OF PATHOGENS IN SOIL
After the wastewater or receiving water is used for irrigation, enteric
pathogens must survive long enough to contaminate crops. Helminths not
only survive in soil but must stay in soil for a period of several days
to develop into an infective stage. Survival times for many enteric
pathogens in soil are reviewed in Table 4. Factors that effect
18
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resistance include number and type of organism, type of soil (structure,
moisture content, pH, amount of organic matter) temperature, amount of
rainfall, amount of sunlight, protection provided by foliage, and
competitive microbial flora. The range of survival times suggests that
pathogens introduced into a field by irrigation with wastewater would,
despite considerable reduction in numbers, survive in the soil until
harvest under some agricultural conditions. Pathogens in soil are more
likely to contaminate foods if the soil is kept moist by intermittent
application of irrigation water. Also, continuous application of
wastewater to soil results in accumulation of pathogens in the soil.
Soil filters microorganisms and they often concentrate near the areas
where plants grow.
CONTAMINATION OF FOODS
Foods become contaminated from water during irrigation (flooding, spray-
ing, or seepage), from soil when the plant grows, when vegetables or
fruits fall on the ground, and when the crop is harvested. They also
are contaminated by dust blowing over the crops or from workers, birds,
and insects that convey organisms from irrigation water or soil to the
foods. Organisms contaminating foods in one of these ways remain on
the food surface until they succumb to dessication, exposure to sunlight,
starvation, or action of other organisms. They do not penetrate into
the vegetables or fruits unless their skin is broken. Survival times of
many enteric pathogens on foods are reviewed in Table 5. These times
suggest ample opportunity for crops that become contaminated during
irrigation or during growth to remain contaminated until harvest. Shell-
fish and watercress trap and accumulate enteric pathogens; thus, they
become particularly hazardous if grown in contaminated waters.
Pathogens are infrequently isolated from foods in fields or after
harvesting. When pathogens are found, they are found in a low percent-
age of samples and usually for only a short time after irrigation.
Studies in which isolations were made are summarized in Table 6.
SURVIVAL, CROSS-CONTAMINATION, AND MULTIPLICATION
Foodborne disease organisms must survive processing and preparation
steps and bacteria usually have to multiply to reach infective levels.
If wastewater-contaminated fruits, vegetables, or seafoods are cooked
so that the contaminated portions reach 165°F (or even lower tempera-
tures for sufficient periods of time), vegetative bacteria (but not
spores), protozoa, helminthic eggs, and most viruses will be killed.
All foods, however, are not cooked before serving, and the temperatures
reached during cooking may be too low to kill pathogens.
Contaminated raw foods bring pathogens into food preparation environ-
ments. These organisms are killed in foods that are thoroughly cooked,
but before cooking they can contaminate the hands of any worker who
touches them, or they can contaminate equipment that they contact.
Such cross-contamination is commonly reported in outbreaks of
79
-------
salrnonellosis; the initial source is usually raw meat or poultry. Some
food service workers and homemakers are aware of this danger, but they
are unaware that wastewater-contaminated vegetables present the same
hazard. Citizens in the United States assume that the fruits, vege-
tables, and shellfish they eat are free from fecal contamination.
But this is the case only if wastewater has not contaminated crops
or the waters in which shellfish grow.
Contaminated foods which are to be eaten raw or used as a raw ingredient
in a salad can support the growth of foodborne disease bacteria under
the following set of conditions: the food must contain sufficient
moisture and essential nutrients to support bacterial growth; the
foods must be held within a temperature range that permits the contami-
nating bacteria to multiply, usually near the organism's optimal tempe-
rature for growth; and the foods must be held at such temperatures for
sufficient time for enough organisms or toxins to be produced to cause
illness in those who ingest the contaminated food.
NUMBERS OF PATHOGENS REQUIRED TO CAUSE ILLNESS
Ingestion of contaminated food does not always result in illness. The
pathogens must be swallowed in sufficient quantity to exceed a person's
threshold of susceptibility if illness is to result. Human volunteer
feeding studies have indicated susceptibility threshold levels of
various enteric pathogens. Table 7 reviews such studies. Conceivably,
wastewater-contaminated food could harbor 10 Shigella dysenteriae 1,
180 Shigella flexneri 2a, or 1,000 Vibrio cholerae biotype ogawa
(numbers found to cause illness in adult volunteers) when they reach
the consumer. Thus, ingestion of foods contaminated at these levels
could result in illness. Such foods could also convey 1 Endamoeba
cola, 10 Giardia lamblia, and 1,000 Vibrio cholerae biotype inaba,
which if ingested could result in infection and carrier status. Ten
thousand Salmonella typhi and 7ibrio cholerae biotype inaba could,
conceivably, be present on foods recently fertilized with night soil,
human manure, or raw sewage; and ingestion of this amount of these
pathogens could cause illness. Certain waterborne outbreaks of these
diseases and other diseases, such as salmonellosis, suggest that even
lower levels of organisms than those indicated by volunteer feeding
studies cause illness. As few as 15,000 Salmonella cubana caused
death in infants who were given contaminated carmine dye for diagnostic
purposes (Lang et al.114). All volunteer studies cited were conducted
on healthy adults. Infants, elderly persons, malnourished persons,
and persons with concomitant illnesses would be more susceptible—
perhaps a one or more log reduction in dosage could result in illness
of such persons. Most of the other organisms in which human feeding
tests have been performed, as well as some of the organisms just cited,
usually require a period of time for multiplication before the large
numbers (100,000 or more) necessary to cause illness would be generated.
Thus, it would be unlikely for an infective dose of salmonellae to be
on lettuce or other raw vegetables, but it is possible for the same
foods to contain an infective dose of shigellae, Ascaris, or £ndamoei>a
20
-------
histolytica. One saving feature is that shigellae and Endamoeba histo-
lytica do not survive long in the competitive environment which occurs
in wastewater, soil, or foods. Salmonellae and many of the other
bacteria which have been mentioned would become problems if contaminated
foods were allowed to stand at room temperatures or refrigerated in
large masses.
OUTBREAKS
On some occasions all circumstances described have occurred and
outbreaks of human illness have resulted. Such outbreaks and source of
contamination and vehicle for each are listed in Table 8. This table,
which is obviously biased by incompleteness, shows that foods grown in
water have been vehicles frequently. Shellfish which were contaminated
in their growing area or during bloating after harvesting were vehicles
in 28 outbreaks; watercress was the vehicle in 10 outbreaks; fish were
vehicles in 3 outbreaks, and shrimp was the vehicle in 1 outbreak.
Vegetables contaminated by night soil, human manure, or raw or partially
treated sewage were reported as vehicles in 21 outbreaks. Fruits were
considered vehicles in only 4 outbreaks. Before 1960, typhoid fever
led the list of foodborne disease outbreaks attributed to wastewater
contamination. The foods incriminated in these outbreaks were found to
have been grossly contaminated with night soil or raw sewage. Outbreaks
of infectious hepatitis are now reported most frequently, followed in
frequency by outbreaks of fascioliasis and cholera. These findings
reflect, in part, improvement in epidemiologic technique.
The epidemiologic evidence presented in many of the reports would not
stand up to critical evaluation. On the other hand, a number of the
investigators proved their hypotheses with epidemiologic and laboratory
evidence. There are enough of these investigations to indicate that
wastewater from mining, industrial, agricultural, community, and
household sources have contaminated foods that, when eaten raw, have
resulted in outbreaks of foodborne illness. These outbreaks will
continue to occur sporadically if raw or partially treated wastewater
is discharged into watercourses which are used for irrigation or
aquaculture, and the contaminating pathogens survive in the wastewater,
in soil, and then on contaminated foods in sufficient quantities.
-------
Table 1. Parasitic Diseases Maintained by the Cycle: Human Feces to
Water or Soil; Water or Soil to Food; Food for Human
Consumption
AGENT
INTERMEDIATE
VEHICLE
Fasciola hepa-
tica
F. gigantica
fresh water
Fasciolopsis
buski
Opisthorchis
felineus
Paragonimus
westermani
Taenia
saginata
Taenia
sollum
fresh water
fresh water
fresh water
soil
(grass)
soil
(grass)
INTERMEDIATE
HOST
FOOD
Clonorchis fresh water
sinensis
Diphylloboth- fresh water
riuzn la turn
Echinostoma fresh water
ilocanum
snail fish
copepods f i sh
snail snails,
clams,
limpets ,
fish,
tadpoles
snail
snail
snail
snail
watercress,
water vege-
tables
water vege-
tables
fish
crabs,
crayfish
beef
pork
22
-------
Table 2. Diseases and Causative Agents Transmissible by Food that Has
Been Contaminated by Wastwater or by Soil that Contains Fecal
Material
DISEASE
AGENT
Bacteria*
Arizona infection
Bacillus cereus gastroenteritis
Cholera**
Clostridium perfringens gastro-
enteritis
Enteropathogenic Escherichia
coli infection
Paratyphoid fever**
Pseudotuberculosis
Salmonellosis**
Shigellosis**
Typhoid fever**
Yersinia gastroenteritis
Arizona hinshawii
Bacillus cereus
Vibrio cholerae
Clostridium perfringens
Escherichia coli (certain serotypes)
Salmonella paratyphi A
Salmonella paratyphi B
Salmonella paratyphi C
Salmonella sendai
Pasteurella pseudotuberculosis
Salmonella (over 1,500 serotypes)
Shigella sonnei
Shigella flexneri
Shigella dysenteriae
Shigella boydii
Salmonella typhi
Yersinia enterocolitica
Viruses
Adenovirus infection
Coxsackie infection
ECHO virus infection
Poliomyelitis
Reovirus infection
Viral hepatitis**
Winter vomiting disease
Ascariasis**
Trichiniasis
Adenovi rus e s
Coxsackie viruses
ECHO viruses
Polioviruses
Reoviruses
Hepatitis virus A
Norwalk agent
Helminths
Ascaris lumbricoides
Trichuris trichiura
Protozoa
Amebiasis**
Balantidiasis
Coccidiosis (Isospora infection)
Dientamoeba infection
Giardiasis
Entamoeba histolytica
Balantidium .coli
Isospora belli, I. hondnis
Dientamoeba fragilis
Giardia lamblia
*Other enteric bacteria which could conceivably be transmitted by foods
but proof is inconclusive: Streptococcus faecalis, S. faecium, Proteus
spp., Providencia spp., Klebsiella spp., Citrobacter freundii, Entero-
bacter spp., Edwardsiella spp., Aeromonas spp., Pseudononas aeruginosa
**Reported outbreaks, see Table 8
23
-------
Table 3. Survival of Pathogens During Various Stages of Wastewater Treatment
Process
PATHOGEN SETTLING
ACTIVATED TRICK-
ANAERO- SAND
STABIL- DISIN-
SLUDGE LING FIL-L BIG DI- FILTRA- DRYING IZATION FECTION
TRATION GESTION TION POND
REFER-
ENCE
Salmonella
typhi
V-
N*
Salmonella
p&ratyphi
Utrecht
-n-
(8)
(9)
(10)
(ID
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(21)
(8)
(14)
(20)
(22)
Shigella
flexneri
(8)
(18)
Vibrio
cholerae
(23)
(8)
Streptococ-
cus faecalis
(24)
(25)
-------
Table 3. Continued
Process
ACTIVATED TRICK- ANAERO- SAND STABIL- DISIN-
PATHOGEN SETTLING SLUDGE LING FIL_ BIC DI- FILTRA- DRYING IZATION FECTION
TRATION GESTION TION POND
Enterovir- + +
uses + +
-H- +
Polio vir- -
uses +
+ + +
+
-
++++ + +
+++ ++
++++ -H-+
-(++)
+-H-+ -l-f
+++
+
Coxsackie -H--H- +++ +/-
viruses +
+++
+
+ +
4--H-+ - + - +
++++ ++++ -H-++ ++ +
+++
ECHO +
viruses +++
REFER-
ENCE
(26)
(27)
(28)
(29)
(30)
(31)
(32)
(33)
(34)
(35)
(36)
(37)
(38)
(39)
(40)
(41)
(39)
(42)
(32)
(35)
(34)
(43)
(39)
(32)
(39)
-------
Table 3. Continued.
Process
PATHOGENS SETTLING
ACTIVATED TRICK- ANAERO- SAND STABIL- DISIN- REFER-
SLUDGE LING FIL- BIC DI- FILTRA- DRYING IZATION FECTION ENCE
TRATION GESTJON TION POND
Hepatitis
virus A
Endamoeba
(44)
histolytica +
++++ ++++ +++ +
+ + + +
+
CO 11 ++
Giardia +
lairiblia
Ascaris + + +++ + - +
lumbri- + + + + -
coides - +
eggs +++
+++ ++ -M- +++4
Tri churls +
trichiura +++ ++
Tapeworm ++++ ++
eggs
Taenia + + + +
saginata +++ ++++ +++ ++++
•H-++ (45)
-H-++ (46)
(47)
(21)
++ (48)
(21)
(46)
(47)
(49)
+++ (48)
(50)
(21)
(50)
++++ (51)
(47)
(52)
- destruction; + survival; ++ over 90% removal; +++ over 50% removal; ++-M- less than 50% removal
-------
Table 4. Survival of Enteric Pathogens in Soil
PATHOGEN
Salmonella
typhi
Salmonellae
Streptococcus
faecalis
Endamoeba
histolytica
Ascaris ova
TYPE SOIL
moist sand
peat
damp soil
soil surface (sunlight)
soil
soil
garden soil (in open)
sandy soil
garden soil (hot house)
sandy soil (hot house)
moist neutral soil
moist arid soil
dry soil
sand
muck
clay loam
sandy loam
adobe
adobe -peat
loam
sand
peat
loam sand
soil and pasture
soil (raw sewage)
soil
sandy soil
soil and pasture
soil
sandy loam
sand
loam
clay loam
muck
moist soil
irrigated soil
soil
SURVIVAL
(in days)
<12
<13
35-74
5-22
70-80
35
32-58
29-36
49-74
53
70
<10-30
<14
<5
12
12
5
21-105
28-100
21-120
2-15
1-2
14-60
>200
46
46-70
35-84
>280
147-259
28-77
33-35
26-63
33-49
40-77
6-8
730-1035
2190
REFERENCE
(53)
(54)
(55)
(56)
(57)
(58)
(59)
(60)
(61)
(62)
(63)
(64)
(65)
(59)
(66)
(67)
(68)
27
-------
Table 5. Survival of Enteric Pathogens on Foods
PATHOGEN
Salmonella
typhi
VEGETABLE
vegetables (leaves and
steins)
radishes
lettuce
SURVIVAL
(in days)
10-31
28-53
18-21
REFERENCE
(55)
(56)
Salmonellae vegetables 40 (68)
vegetables 28 (69)
beet leaves 21
tomatoes (laboratory) 20 (70)
tomatoes (field) 3
soil and potatoes >40 (71)
carrots >10
cabbage and gooseberries > .5
tomatoes 3 (72)
Shigella clams and shrimp >60 (73)
sonnei and oysters >40
S. flexneri tomato (surface) 2 (74)
S. sonnei tomato (tissue) 10
apple (skin) 8
Vibrio vegetables 5 (75)
choleras dates
-------
Table 6. Recovery of Pathogens from Foods Contaminated by Wastewater
PATHOGEN FOOD SOURCE OF CONTAMINATION REFERENCE
Salmonella
typhi
leaf tips
radishes
lettuce
contaminated soil
contaminated soil
contaminated soil
(55)
(56)
Salmonella
(other types)
Salmonella,
shigella,
other bac-
terial path-
ogens
(serologic
evidence)
Ente ropatho-
genic
Escherichia
coli
celery
vegetables
fish
green onions
white perch
fish
irrigation water
irrigation water
river water
irrigation water
river water near heavily
populated areas
(82)
(83)
(84)
(85)
(86)
river water
(87)
Enteroviruses vegetables
(Polio, ECHO, oysters
Reo, Coxsackie)
Ascaris ova
Helminth ova
lettuce
cabbage
vegetables
cucumbers
tomatoes
carrots
irrigation water
sewage-contaminated
sea water
irrigation water
irrigation water
irrigation water
irrigation water
irrigation water
irrigation water
(88)
(89)
(48)
(90)
29
-------
Table 7. Clinical Response of Adult Humans to Varying Challenge Doses of Enteric Pathogens
ORGANISM
(strain)
Challenge doses REFERENCE
)° 101 102 103 10" 10s 10* 107 108 109 1010 1011
Shigella
dysenteriae
(1) (A-l)
(1) (M 131)
Shi gel la
flexneri (w)
(2a)
(2a)
Vibrio
choleras
inaba 569B
(unbuffered)
inaba 569B
(+NaHC03)
ogawa
(4NaHCO )
j
Salmonella
typhi
(Quailes) vi
(Zermat) vi
(Ty2V) vi
(0-901)
(Ty2W)
(Quailes)
(Quailes)
+ +4 (91)
4 44 444 4444 (91)
+++ (92)
4 +++ -H-++ +44 4444 (93)
4 444 444 444 (94)
++ 44 441 (95)
(4) 444 4441 4441 441 (95)
44 +41 (95)
44 44 4444 4444 (96)
++4 (96)
44 (96)
44 (96)
4 (96)
4 44 4444 (97)
++ (98)
-------
Table 7. Continued
ORGANISM Challenge doses
10° IO1 IO2 IO3 10* 10S IO6 IO7 10fl IO9 IO10 IO11 ^ra^NCE
(strain)
Salmonella
newport + ++
Salmonella
bareilly •+• ++
Salmonella
anatum(I) - +
(II) 4-
(III) --++ + +
* ++ 4- +
Salmonella
meleagridis (I) - - - ++
(ID - ++
(III) - + ++
* +++ +++
Salmonella
derby - ++
Salmonella
jpullortun(I) ______ ++++
(II) _____ ++++
(III) _____ +4.4.4.
(IV) -----++
(99)
(99)
(100)
(100)
(100)
(101)
(100)
(100)
(100)
(101)
(99)
(102)
(102)
(102)
(102)
-------
Table 7. Continued
ORGANISM Challenge doses
10° 10* 102 103 10" 105 106 107 108 109 1010 1011
(strain)
Escherichia
coJi(Olll:B4) +-H- 444 444
(055 :B4) 444 444 4444
(O6:H16) 44 444
(O124:K72:H-) + (+>
(O143:K?:H-) (4) (4) 444
(O144:K?:H-) - 4 444
(O148:H28) 4 4444
REFERENCE
(103)
(104)
(105)
(105)
(105)
(105)
(105)
Streptococcus
faecalis var.
liquefaciens
Clostridium
perfringens
type A (Heat-
resistant)
Clostridium
perfringens
type A (Heat
sensitive)
(106)
(107)
(108)
-------
Table 7. Continued
U)
ORGANISM Challenge doses
Feces 10° 101 102 103 10** 105 106 107 108 109 10i0 1011
(strain)
Endamoeba
coli (+) (++) {++) - (++++)
Giardia
lamblia - (++++) {+-»•) (++++) (++++) (++++)
Norwalk
agent
( virus)! ++
** 2 +++
3 +
Hepatitis
virus A +++
(fecal ++
filtrates)
REFERENCE
(109)
(110)
(111)
(112)
(113)
- = 0, + = 1-25, ++ =* 26-50, +++ = 51-75, ++++ = 76-100 percent of volunteers developing illness
* Refeeding trials of volunteers who months before became infected by the same strain
**1,2,3 refers to serial passages of stool filtrates
(+) Infections without illness
1 = cholera-like diarrhea
-------
Table 8. Outbreaks Associated with Foods Contaminated by Sewage or
Wastewater
DISEASE
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever
Typhoid fever,
gastroenter-
itis
Amebiasis
Taeniasis
Typhoid fever
SOURCE OF CONTAMINATION
Sewage-polluted waters
Sewage sludge fertilizer
and irrigation
Sewage- contaminated
watercress beds
Sewage-polluted water
Sewage-polluted water1
Human manure
Privy-polluted water*-
cress beds
Sewage irrigation
Sewage irrigation
Sewage-polluted water
Sewage-polluted water
Sewage-polluted water
Fecal-polluted (privy
and boats) water
Sewage irrigation
Sewage irrigation
Sewage-polluted wastes
FOOD
oysters
celery
watercress
shellfish
oysters , raw
vegetables and
fruits
rhubarb
watercress
vegetables,
blackberries
raw vegetables
oysters
oysters
oysters
oysters
vegetables
beef
oysters
REFERENCE
(115)
(116)
(117)
(118)
(119)
(120)
(121)
(122)
(123)
(124)
(125)
(125)
(126)
(127)
(128)
(129)
Typhoid fever,
Paratyphoid
fever
Typhoid fever
Shigellosis
Amebiasis
(privies and raw sewage)
Secondary sewage treat- vegetables
ment (activated sludge)2
plant effluent irriga-
tion and wash water
Sewage clams
Irrigation water cabbage
(Primary treatment plant
effluent) 3
Night soil vegetables
(130)
(131)
(132)
(133)
-------
Table 8. Continued
DISEASE
Typhoid fever
Ascariasis
Typhoid fever
Typhoid fever
Ascariasis
Tyhpoid fever
Salmonellosis
Typhoid fever
Typhoid fever
Typhoid fever
Ascariasis
Ascariasis
Hookworm
infection
Viral
hepatitis
Typhoid fever
Diphylloboth-
riasis
Fascioliasis
Viral
hepatitis
Typhoid fever
Viral
hepatitis
SOURCE OF CONTAMINATION
Sewage-polluted water-
cress beds
Sewage spray irrigation
Sewage manure
Night soil
Night soil
Sewage irrigation
Sewage irrigation and
sludge
Human fecal material
as manure
Human fecal material
as manure
Night soil
Night soil
Night soil
Sewage farming
Sewage-polluted water
Sewage l
Sewage-polluted water
Animal feces1
Sewage-polluted water
by primary treatment
effluent, raw sewage,
and septic tank dis-
charges3
Sewage-polluted water
Sewage-polluted water
(overtaxed treatment
plant effluents)
FOOD
watercress
vegetables
vegetables
vegetables
vegetables
apples
vegetables
endive
raw salad
vegetables
vegetables
vegetables
vegetables
oysters
vegetables,
fruits ,
shellfish
fish
watercress
clams
oysters
clams
REFERENCE
(134)
(135)
(67)
(177)
(178)
(179)
(136)
(137)
(137)
(68)
(68)
(138)
(139)
(140)
(141)
(142)
(143)
(144)
(145)
(146)
35
-------
Table 8. Continued
DISEASE
Viral
hepatitis
Viral
hepatitis
Viral
hepatitis
Fascioliasis
Cholera
Fascioliasis
Salmonellosis
Viral
hepatitis
Viral
hepatitis
Taeniasis
Minamata
disease
(organic
mercury
poisoning)
Salmonellosis
SOURCE OF CONTAMINATION
Sewage-polluted water
(treatment plant by-
passed)
Sewage-polluted water
Sewage-polluted water
Sewage-polluted water1
Sewage-polluted water
Sewage-polluted water1
Dead animal in polluted
water from which cows
drank
Sewage-polluted water
Sewage-polluted water
Human feces contaminated
trench silo
Industrial waste
Sewage-polluted water
FOOD
oysters
oysters
oysters
watercress
shrimp
watercress
raw milk
oysters
clams
rare beef
fish, shellfish
white fish
REFERENCE
(147)
(148)
(153)
(149)
(150)
(151)
(152)
(153)
(153)
(154)
(155)
(156)
(157)
Fascioliasis
Viral
hepatitis,
gastroenter-
itis
Gastroenter-
itis
Salmonellosis
(Animal in-
fection)
by untreated sewage
(culture positive)
Animal feces contami- watercress
nated watercress bed
Sewage-polluted water clams
by cesspool
Sewage-polluted water1 clams
Animal dung slurry used grass
to irrigate pastures
(158)
(159)
(159)
(160)
36
-------
Table 8. Continued
DISEASE
Viral
hepatitis
Fascioliasis
Cysticercosis
(Animal in-
fection)
Ouch-ouch
disease
(cadmium
poisoning)
Fascioliasis
Viral
hepatitis
Cholera
Viral
hepatitis
Salmonellosis
(Animal in-
fection.
possible
human cases)
Viral
hepatitis
Viral
hepatitis
Cholera
Cholera
SOURCE OF CONTAMINATION FOOD
Sewage-polluted water1 clams
Animal feces contami- watercress
nated water used for
watercress beds
Sewage- contaminated water
irrigation water used
for cattle watering
Mining waste used to rice
flood rice fields
Animal feces contami- watercress
nated watercress bed
Sewage-polluted water clams
Sewage-polluted water1 shellfish
Septic tank effluent watercress
contaminated water
Human sewage flowing grass
over grazing land
Sewage-polluted water1 clams
Sewage-polluted water1 oysters
Sewage-polluted water mussels
for growing and freshen-
ing
Raw sewage irrigation vegetables
REFERENCE
(161)
(162)
(163)
(164)
(165)
(166)
(167)
(168)
(169)
(170)
(171)
(172)
(173)
(174)
(175)
(2)
1 Implied
2Secondary treated sewage
3Primary treated sewage
37
-------
REFERENCES
1. Bryan, F. L. 1972. J, Milk Food Technol. 35:632.
2. World Health Organization. 1973. Reuse of Effluents: Methods of
Wastewater Treatment and Health Safeguards. World Health Organ.
Tech. Rept. Ser. No. 517.
3. Rudolfs, W., L. L. Falk, and R. A. Ragotzkie. 1950. Sewage Ind.
Wastes 22:1261.
4. Rudolfs, W., L. L. Falk, and R. A. Ragotzkie. 1950. Sewage Ind.
Wastes 22:1417.
5. Greenberg, A. E. and B. H. Dean, 1958. Sewage Ind. Wastes
30:262.
6. Rollins, S. A. 1966. Adv. Appl. Microbiol. 8:145.
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THE EVALUATION OF MICROBIAL PATHOGENS
IN SEWAGE AND SEWAGE-GROWN FISH
by
R. LeRoy Carpenter, Harold K. Malone, Ara F. Roy,
Aaron L. Mitchum, Herbert E. Beauchamp and Mark S. Coleman*
A significant removal of pathogenic bacteria and viruses during the
process of the lagoon method of sewage treatment is well documented,
though not entirely understood!> 2, s, 4. Stabilization ponds with a
30-day retention time can achieve a reduction of up to 99 percent3.
OkunS reported 99.99 percent reduction of coliforms; Drew^ found 99.6
percent reduction in summer and 96.8 percent in winter.
The use of the traditional coliform test to indicate the likelihood of
pathogenic bacteria and viruses has been widely questioned'7 since human
pathogens, unlike coliforms, tend to die when not in the temperature
and chemical environment similar to a host^. The health risks involved
in the reuse of wastewater reflect the range of pathogenic organisms
found in the community producing the sewage. For example, sewage irri-
gation of vegetable crops was found to be linked to an outbreak of
cholera in Jerusalem in 1970. In India hookworm and gastrointestinal
infections are more common among workers on sewage farms than the gene-
ral population. On the other hand, a follow-up study of the health of
workers at sewage treatment plants in the U.S.A. did not reveal any
excess risk of disease or disability3.
Public health officials have noted a mushrooming interest in beneficial
uses of wastewater ox^er the past two years. This increased interest
is mainly due to the following: (1) the realization that many parts
of this country are outgrowing or haxre outgrown their freshwater
supply^; (2) the demands for new sources of inexpensive protein to feed
an expanding animal and human popuJatior; (3) the rising cost of ni-
trogen and phosphorus fertilizers to support agricultural needs^; and
last, but not least, (4) the desperate need of municipalities to off-
set the high cost of meeting the federal and state effluent standards
for sewage treatment facilities-^.
*R. LeRoy Carpenter, M.D., M.P.H., Commissioner of Health; Harold K.
Malone, Assistant Chief, Laboratory- Services; Ara F. Roy, Director,
Sanitary Bacteriology Division; Aaron L. Mitchum, Microbiologist II;
Herbert E. Beauchamp, Director, Virology Division; Mark S. Coleman,
Director, Water Quality Monitoring and Research Division, State Depart-
ment of Health, Northeast Tenth and Stonewall, Oklahoma City, Oklahoma
73105. y
-------
This new surge of interest in beneficial uses of wastewater has prompt-
ed the Oklahoma State Department of Health to look objectively at the
health hazards associated with human and animal exposure to sewage ef-
fluents. Such a preliminary investigation was carried out from July,
1973 through February, 1974 at the Quail Creek Sewage Lagoon System
near Oklahoma City. The system is made up of six cells approximately
six acres each as shown in Figure 1. It serves a residential district
of approximately 10,000 persons producing approximately one million
gallons of sewage/day. The first two cells are aerated with the con-
ventional Hinde Air-Aqua System; the four following are operated in
series at a level of four to five feet. An engineering flaw in the
system is that a modification necessary to convert flow from parallel
to series caused a short circuit in cell #4 as shown by the arrows in
Figure 1.
In May, 1973, 25,000 two to four-inch channel catfish fingerlings were
stocked in each of cells #3 and #4; 35 pounds of adult Golden Shiners
(Notemigonus crysoleucas) were stocked in each of cells #5 and #6. In
July, 175 three-inch Tilapia nilotica and five pounds of Fathead Min-
nows (Pimphales promelas) were introduced into cell #3 only.
Despite what was considered as adequate screening between the test
cells which were dry when the study began and the proceeding two con-
ventional cells, wild fish including Black Bullhead (Ictalurus melas),
Green Sunfish (Lepomis cyanellus), and Mosquitofish (Gambusia affinis)
contaminated the test cells.
MATERIALS AND METHODS
One hundred seventy-nine fish on 12 different dates and 77 water
samples on 11 different dates were collected over a seven-month period
beginning July 1, 1973 and ending January 28, 1974. While there was
some variation, most water collections consisted of four liter catch
samples of the untreated sewage and similar samples of the effluent
from each of the six cells. A total of 34 samples of five channel cat-
fish each were collected from cells #1 through #5 during 12 fish-
sampling visits. Tilapia, Green Sunfish and Bluegill were collected
one time each from cells #3, #4 and #5 respectively. Water samples
were processed according to the "APHA. Standard Methods of Examination
of Water and Wastewater."12
Water samples were examined for total coliform, fecal coliform, fecal
streptococci, and pathogenic enteric bacteria using the membrane filter
methodology recommended by the APHA13. For isolation of pathogenic
enteric bacteria, 100 ml portions of sample were passed through 0.45
micron pore size membrane filters. The membranes were then placed
in Hajna's gram negative (GN) enrichment broth and incubated overnight.
-------
•ft-
Qs
QUAIL CREEK LAGOON SYSTEM
FIGURE 1
-------
The broth was then streaked onto Bismuth Sulfite Agar, Brilliant Green
Agar, XLD Agar, and MacConkey's Agar. Suspicious colonies were con-
firmed by conventional biochemical and serological tests as described
by Edwards and Ewing1^. GN broth was initially selected for its known
superior ability to yield shigellae species while it is also reported
to be suitable for enrichment of Salmonella species1^, ^. Failure
to isolate Salmonella from the first nine samples examined led to the
addition of a second membrane which was enriched in Tetrathionate broth
with Brilliant Green added1^. This broth was then used to streak addi-
tional plates of Brilliant Green and Bismuth Sulfite Agars.
Subsequent control studies in our laboratory showed that Tetrathionate
broth with Brilliant Green added can recover essentially all Salmonella
seeded at low levels into lagoon water while, by comparison, the yield
from Hajna's GN broth was reduced by a factor of greater than ten.
For virus studies, 50 ml aliquots of lagoon water were centrifuged at
2,000 rpm. The supernatant was decanted, treated with antibiotics and
0.1 ml portions inoculated into Rhesus Monkey Kidney, Wi38 and, when
available, HEp2 tissue culture tubes. Cultures showing cellular de-
struction were examined by conventional methods for viral identifica-
tion^. Cultures not showing cellular destruction were passed once to
the same cell line before discarding as negative.
It was recognized that the catch sample method has a comparatively low
degree of sensitivity; but the elaborate concentration techniques em-
ployed by Wallis, Melnick and Fields17' 18 and Metcalf, Vaughn and
Stiles1^ were beyond the financial scope of this study. Control
studies conducted by seeding of the lagoon water with low levels of
Coxsackie A9 enterovirus followed by the above procedure showed no
apparent interference to the recovery of virus by naturally occurring
constituents in the lagoon water. Samples of fish were carefully dis-
sected and the skin, upper intestines, cloaca, and muscle were cul-
tured separately. However, after the first two collection dates, skin
was combined with muscle to constitute one specimen, and, all viscera
were pooled to constitute a separate specimen. After homogenizing,
an aliquot of each pool was used for both virus and bacterial study.
For isolation of human pathogenic enteric bacteria, a 2 ml portion of
the homogenate was enriched by overnight incubation in 10 ml of Hajna's
GN broth followed by streaking for isolation as indicated previously
for water. Virus examination was accomplished by processing the homog-
enate according to the procedures in use for human feces and tissue by
the Oklahoma State Department of Health Laboratory16. The processed
material was assayed by inoculation into Rhesus Monkey Kidney, Wi38
and, when available, HEp2 tissue culture systems.
-------
Results of the study are shown in Figure 2. The log count of fecal
coliforms per 100 ml is shown in the bars and sampling dates are shown
along the horizontal axis. The top shaded area shows the log of number
of coliforms in the raw influent to the system and the lower portion
of the bars, shown by the dotted area, represents the treated effluent
as it passed out of the last of the six cells into the receiving
stream.
Inspection of these bars readily shows that there is a remarkable re-
duction of fecal coliform bacteria to less than detectable limits in
a standard 50 ml portion in three separate samples.
The pathogens isolated are shown by the boxes at the bottom:
August 13 there was an isolation of Edwardsiella tarda.
December 17 there was an isolation of ECHO 1 enterovirus.
January 14 there was an isolation of Salmonella newport.
Figure 3 shows the average log of the count of indicator organisms per
100 ml isolated on the 11 water-sampling dates. As the wastewater
flows through the system from raw influent on the left to effluent from
the last lagoon on the right, one can see a progressive reduction in
the indicator organisms. By the time the effluent passes through the
third cell, it is found to contain less than ten fecal coliform organ-
isms/100 ml, and remains at this low level as the effluent passes
through the last three cells. It is interesting from a public health
standpoint that of the three pathogens isolated in water during the
study, two were found in raw influent and one was in cell #2. No
pathogens were found in wastewater beyond the first two conventional
cells; nor in any of the cells containing the test fish; nor in any
of the 179 fish sampled.
In conclusion, it can be said that this study has confirmed the pre-
vious observations of others that indicator coliform organisms are
efficiently removed in a lagoon-method wastewater-treatment systeml*
2, 3, 4. xhis study has shown that human pathogens are rare in those
wastewaters tested and in fish grown in those wastewaters beyond the
raw or first two conventionally-operated cells.
Though it was not within the scope of this study to evaluate the ef-
fect of extended lagooning, per se, on removal of coliforms, future
investigators should design studies in such a way as to simultaneously
compare the results in lagoons both with and without the addition of
fish.
50
-------
LOG COUNT
PER 100ml
i
i
i
QUAIL CREEK LAGOON SYSTEM
FECAL COLIFORM
INFLUENT VS EFFLUENT
AND
PATHOGENS ISOLATED
JULY 1973-JANUARY I974
I
\
INFLUENT
EFFLUENT
i
PATHOGENS ISOLATED
III I I
1973 JULY JULY JULY JULY AUG
2 9 16 30 13
AUG
27
I
OCT
NOV
$
I
1
JAN 1974
28
FIGURE 2
-------
1
6
QUAIL CREEK LAGOON SYSTEM
INDICATOR BACTERIA
AVERAGE COUNT PER CELL
AND
PATHOGENS ISOLATED
TOT ALGOL I FORM
AVERAGE LOG COUNT PER 100 ml
FECAL COLIFORM
PATHOGENS ISOLATED
RAW
CELL 1
CELL 2
I
CELL 3
FIGURES
I
CELL 4
CELLS
I
CELL 6
-------
Many economic and conservation-oriented pressures are prompting a surge
of interest in using domestic wastewater for production of crops and
fish. This study supports this concept. But, as Shuval so aptly
pointed out, much -work yet remains to be done in accurately determining
the public health hazards associated with such practice2^.
We should investigate the potential dangers to the handlers, harvesters
and processors of fish and shellfish grown in wastewaters and not limit
our attention to the consumer only. We must sharpen our techniques for
isolating pathogenic viruses and bacteria from wastewaters, use them
more frequently in our monitoring programs and not rely solely on coli-
form indicators as we have in the past. Parasites such as worms and
amoebae should not be overlooked. And last, where possible, we should
use sound epidemiological methods to correlate the presence or absence
of disease in a community with those organisms found in that communi-
ty's wastewaters.
-------
1. Berg, Gerald. Virus Transmission by the Water Vehicle.
II Virus Removal by Sewage Treatment Procedures. Health
Library Science. _2_:90, 1966
2. KLock, John W. Survival of Coliform Bacteria in Waste-
water Treatment Lagoons. Journal of Water Pollution
Control Federation. 43:2071-2083, October 1971.
3. The Reuse of Wastewater. WHO Meeting of Experts on the
Reuse of Effluents: Methods of Wastewater Treatment and
Health Safeguards (1973) Report, Geneva (World Health
Organization techn. Rep. Ser., No. 517). WHO Chronicle
27:492-495, November 1973.
4. Little, John A., Bobby J. Carroll and Ralph E. Gentry.
Bacterial Removal in Oxidation Ponds. Second International
Symposium for Waste Treatment Lagoons, June 23-25, 1970,
Kansas City, Missouri. Lawrence, Kansas, Ross E. McKinney,
University of Kansas, pp. 141-151.
5. Okun, D. A. Experience with Stabilization Ponds in the
U.S.A. Bulletin World Health Organization 26:550, 1962.
6. Drew, R. J. Field Studies of Large Scale Maturation Ponds
with Respect to their Purification Efficiency. Journal and
Proceedings of Inst. Sewage Purification 3_:1-16, 1966.
7. Northington, Charles W., Shih L. Chang and Leland J. McCabe.
Health Aspects of Wastewater Reuse. Water Quality Improve-
ment by Physical and Chemical Processes. Austin, University
of Texas Press, Ed. by Earnest F. Gloyna and W. Wesley
Eckenfelder, Jr.
8. Berg, Gerald. Integrated Approach to Problem of Viruses
in Water. Journal of Sanitary Engineering Division,
American Society of Civil Engineers, p. 867-882,
December 1971.
9. Heckroth, Charles W. Reuse and Recycling: What's Ahead?
Water and Wastes Engineering, p. A-l - A-11, January 1973.
54
-------
10. Is There a Protein Problem? Protein Advisory Group of the
United Nations System, Statement No. 20, March 1, 1973.
WHO Chronicle, 27_:487-491, November 1973.
11. Wall Street Journal, October 15, 1973. Dallas, Dow Jones
§ Co.
12. American Public Health Association. Standard Methods for
the Examination of Water and Wastewater, 13th edition. New
York, American Public Health Association, 1971, p. 657-660.
13. ibid, p. 692-704.
14. Edwards, P. R. and W. H. Ewing. Identification of
Enterobacteriaceae, 3rd edition. Minneapolis, Burgess
Publishing Company, 1972, p. 8 f.
15. Hajna, A. A. A new specimen preservative for gram negative
organisms of the intestinal group. Public Health Laboratory.
13:59-62, 83, 1955.
16. Lennette, E. T. and N. J. Schmidt, ed. Diagnostic Procedures
for Viral and Rickettsial Infections, 4th edition. New
York, American Public Health Association, p. 560 f, 1969.
17. Wallis, Craig, and Joseph L. Melnick. Mechanism of Enhance-
ment of Virus Plaques by Cationic Polymers. Journal of
Virology. American Society for Microbiology, 2_: 267-274,
April 1968.
18. Wallis, Craig, Joseph L. Melnick and Joseph E. Fields.
Detection of Viruses in Large Volumes of Natural Waters by
Concentration on Insoluble Polyelectrolytes. Great Britain,
Water Research, 4_: 787-796, 1970.
19. Metcalf, T. G., J. M. Vaughn and W. C. Stiles. The Occurrence
of Human Viruses and Coliphage in Marine Waters and Shellfish.
FAO Technical Conference on Marine Pollution and its Effects
on Living Resources and Fishing, Rome, Italy, December 1970.
20. Shuval, Hillel I., and Nachman Gruener. Health Considerations
in Renovating Waste Water for Domestic Use. Environmental
Science $ Technology, 7_: 600-604, July 1973.
55
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MORBIDITY RISK FACTORS
from
SPRAY IRRIGATION WITH TREATED WASTEWATERS
by
Geoffrey B. Stanford* and Rafael Tuburan*
MRCS HMR FRPS B. A.
In this paper we present the interim conclusions of an ongoing
literature review. We have tried to find out whether properly treated
wastewaters from a properly designed and correctly operated wastewater
treatment plant, which provides at least secondary treatment, are safe
from the health viewpoint. In particular, we wished to find out whe-
ther aerosols generated from these treated wastewaters present a signi-
ficant pathogen risk. If not, we believe, their use on land for irri-
gation and for their fertilizer value can and should be encouraged for
a variety of environmental, economic, agricultural, and social reasons.
In our search we have adopted the antagonist attitude. We have sought
to prove to ourselves that there are valid reports which show that di-
sease has occurred from this practice in the past, and therefore that
the practice must be controlled.
Since we have not yet found any such reports, we continue to recommend
that the many advantages known to accrue from this practice outweigh
the apparent chances of a health risk, and that the practice should be
encouraged. We will now show our reasoning, based on the findings we
have examined so far.
• School of Public Health, University of Texas at Houston
56
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FINDINGS
Raw Night Soil
There is no room for doubt that, in an area where an enteric infection
is endemic in a human population, one important factor by which ende-
micity is maintained is the practice of applying fresh raw sewage as a
fertilizer on to crops which are eaten fresh and raw by man.l There is
continuing 3Jdscussion whether this same practice helps to maintain re-
sistance to the disease in the resident population. But that is irre-
levant to the argument that the practice transmits disease to visitors,
and therefore is a public health risk.
We have not yet found documentation whether pulmonary infection can be
spread in this way. There is published evidence that bathing in sur-
face waters which are contaminated by human fecal matter may have cau-
sed disease.2
Urban Wastewaters
In urbanized communities where the flushing toilet and sewer system
are in use, the human waste load is subjected to a dilution of some
200-2000 times - or more, if the storm drains are combined with the
wastewater sewers. Further, in properly sewered urban societies, the
endemic morbidity, and hence the average pathogen load per person, is
reduced by a factor of some 10-100 times. These two factors combined
produce a total pathogen reduction per unit volume of between 2 x 10^
and 2 x 105 when raw modern city sewage is compared with raw night
soil applied to crops or to land. A further reduction in viable patho-
gen load from urban sewers is caused by the extended time-delay during
transport from source to crops.
Some cities have continued or have re-introduced^ the 'sewage farm1
procedure first practiced in the late l800's. In this technique the
raw sewage is applied year after year to a limited area of land, which
is used for crops or for pasture. In spite of the large quantities
which have routinely been applied, in some cases over many years conse-
cutively, there are no recent reports of disease resulting.^ Indeed,
one such city reports that the carcasses of cattle grazed on this land
attract better-than-average prices in the market because of their high-
er quality.5
Sedimentation - It is generally accepted that treatment by primary
settling reduces the general pathogen load in the supernatant waters.
There is evidence that primary settling carries most of the viral load
into the sludge, probably by adsorption;0 this effect is accentuated
by chemical flocculants;' the degree of inactivation of this virus load ^
is not yet agreed. The supernatant waters retain a significant proper- c\j
tion of the initial nonviral pathogens, and the balance settles with o
the sludge. The ultimate degree of any reduction
57
-------
of the total initial load depends on the time delay during travel in
the sewers and in the settling system, and can be attributed to
normal die-off, possibly accentuated by the bacterial activity of
metabolic byproducts of non-pathogenic micro-organisms.
Aerobic Treatment - It is generally accepted that properly conducted
aerobic treatment, whether by biological filter or by activated sludge
tanks, in a plant which is not being overloaded or mismanaged, can re-
duce the non-viral pathogen load by better than 99?, although this is
seldom achieved in practice.
'When the effluent waters are properly chlorinated to the required stan-
dards, they are generally accepted to be safe for discharge into a
waterway when judged by the criteria in force. There is satisfactory
evidence that such waters are acceptable to the public for irrigation
of agricultural soil, parkland, and golf courses,0 since several states
have set criteria to regulate this practice.^10 Indeed, in many areas
today the more expensive developments, which include a golf course as
one of their amenities, are routinely requesting permits to irrigate
their courses with the effluent from their treatment plants.11 We have
found no evidence of disease reported from this practice.1
Anaerobic Sludge - While there are reports of disease being acquired
from sludge,13 it is likely that these may have been primary settled
sludge, since the majority of treatment plants in the U.S.A. are still
confined to this simple procedure.
There is satisfactory evidence that secondary anaerobic treatment of
sludges, properly conducted in a properly designed plant which is not
being overloaded, produces a sludge which is acceptable as safe for
public use as a soil improver without further disinfection or sterili-
zation. This sludge has been applied wet (fresh) onto farmland and on
to city parkland11* and children's play grounds.15 We have found no in-
stance of reported disease from this practice.
Further, such sludge, after drying, is saleable16 as a profitable ven-
ture over long periods of time both retail and contract10 when pro-
perly marketed. We have found no instance of reported disease from
this practice.
Irrigation - We have found no instance of disease reported from spray
irrigation with chlorinated secondary effluent that has been properly
treated ('green water'). This is not surprising. If pathogens were
a risk from drift, spray, or aerosols generated from sewage, surely
the clinical risk would be greatest where the concentration is great-
est - in the sewage works, near the aerobic treatment unit? We have
found no evidence that long-term or newly introduced operators have
disease attributed to this; indeed some experts have suggested that
the morbidity of sewage plant operators is less than the morbidity of
the general public. Perhaps a more sensitive indicator could be the
58
-------
adolescent school children visiting the sevage plant as a science
course field trip; a letter from the National Science Teachers Associa-
tion tells us that "From inquiries to the U. S. Public Health Service
and the Montgomery (Maryland) Health Department, we have learned of no
reported illnesses to students following visits to sewage treatment
plants, nor could we find that any guidelines have been developed or
are in practice as precautions for such visits. Also, the student tours
director for the Washington Suburban Sanitary Commission told us that
no special precautions have been observed in their tour program, nor
did he know of any illnesses to students following tours of that facili-
ty. "'19
CONCLUSIONS
The Published Evidence
In short, our review of the literature has not yet provided an instance
in which satisfactory evidence is given that a disease incident has
arisen from using treated sewage products. By treated we mean that the
evidence provided shows that during the days preceding the incident:
the treatment plant was operating within design capacity; that the unit
processes in that treatment plant were being operated properly and were
functioning properly; and that the effluent quality was within the cri-
teria required. In other words, we suggest that before an incident can
Justifiably be attributed to the use of treated waste waters, it must
be shown that those wastewaters were being fully and properly treated
during the period of time which could have been implicated. Until that
has been demonstrated one would be calling in question not the health
risks of using these materials, but the effectiveness of the design and
the operation of that plant. And that demonstration should not be dif-
ficult in the future, even though it may, on occasion, have been so in
the past.
THE MAGNITUDE OF THE RISK
Infectivity
In actual practice, what is the likely risk that pathogens originating
in a sick person or a carrier will gain entry to a susceptible person?
In the U.S.A. the pathogen endemicity load is now low. Will the com-
bined effects of attrition by die-off over time, of dilution into a
large volume of water, of attenuation by spread over a large area of
land, of sterilization by solar radiation, and of degradation by soil
organisms - will all these effects, working in series, reduce the real
risk to below the level of risk in a city street20 to below that of the
risk from food obtained from commercial sources, 1 or to below that in
an office building? We can suppose so, but this also requires evi-
dence, and we have not yet found that in the literature.
-------
Spread - Much has been published about the effect of the configuration
of the spray-nozzles of fuel injectors for reciprocating and for jet
engines, on the size distribution of the droplets produced. There is
also information about the design of applicators for agri-drugs in the
field, and about the factors concerned in reduction of drift and of wind
spread: the smaller the droplet, the further it travels: to reduce
drift, droplet sizes should be larger than 500 microns.2^ There is
literature which suggests that droplets often nucleate around a bacter-
ium; and that the physical changes which occur in the droplets during a
short time after its formation are complex: these include relative
change of concentration of solutes across the diameter, and dessicca-
tion; it may be speculated that theE changes may be so fast as to pro-
duce effects comparable to freeze-drying, and so may preserve a patho-
gen rather than destroy it. The free-floating spherule so formed be-
haves like a dust particle. Droplets and dust can travel a considera-
ble height into the atmosphere before coming down again, 3 or they may
be blown long distances near ground-level before reaching their final
resting-place - 50 miles has been recorded for an aerosolized agri-
drug." These effects, recorded in the literature from other special-
ties, require to be related to our questions.
Susceptibility - If we assume that a pathogen has survived these ordeals
and has gained entry to a human being, what are the chances of its
causing an infection? Will that infection be sub-clinical and cause no
apparent loss of health? and if so will it produce another carrier?
Or will it cause recognizable disease which will affect the patient or
society adversely? There is evidence that mere entry is not always
sufficient to start an infection; the person has a battery of defense
mechanisms, and the entrant pathogen is more likely to be destroyed
than not. But there is evidence that although it requires many bacteria
to produce infection,2U a single viral TCIDjo can do so if it achieves
a susceptible target - for example, the lung alveolus; in this instance
small droplet size (below 2.5 microns diameter) is a required factor.
There is agreement that although bacteria and perhaps parasitic cysts
can confidently be removed by conventional sewage plants the same can-
not be said with the same confidence about viruses.
HEED FOR INFORMATION
We can summarize as follows:-
1). A literature search has not yet revealed any incidence of disease
from irrigation with properly treated sewage products.
2). Irrigation techniques should strive to eliminate the formation of
any droplets that are smaller than 500 microns in diameter.
3). Researches should focus on determining the viability of pathogenic
organisms through the several attenuation pathways to which they are
normally subjected, so that we can quantify the actual risks of infec-
tion. Then we can work to minimize those risks if they prove to be
significant.
-------
DISCUSSION
We recognize that in this paper we have posed more questions than ve
have provided evidence or answers - and properly so. It has been our
purpose to reveal those questions, and so, hopefully to cause the need-
ed investigations to start.
Nevertheless, the existing information does not warrant any restrictions
on the use of properly treated wastewaters for land application; "but it
does support a case for careful management of sewage plants whose pro-
ducts are to "be used in this way. Both the "better management of waste--
waters, and the greater use of the treated end-products are commended
by government and professional2" agencies as a national goal; they are-
therefore likely to be achieved soon. Our investigations so far conf:irm
the need for both.
This brief paper is not claimed to be exhaustive, nor are our findin/gs
conclusive: it is designed more to share with you the large areas of
doubt that exist both for and against there being a significant patho-
gen risk.
At the International Conference on Land for Waste Management held iin
Ottawa last October, a group of conferees came to the following conclu-
sions :-
1. NEED FOR COORDINATED INFORMATION CENTER
Nobody present knew of a coordinated bibliography or information refer-
ence center which meets the present needs of administrators, field wor-
kers, and research workers, about the pathogen risks from use of treated
wastewater products. This need is growing.
2. NEED FOR COORDINATED RESEARCH
The information so far gathered by those who were present is inconclu-
sive and/or inadequate to support policy recommendations or decisions
at field, administrative, or guideline legislative levels. Basic re-
search is urgently needed. Over-restrictive legislation based on cau-
tion might soon be introduced which could obstruct trial of innovative
procedures unless such basic information quickly becomes widely avail-
able.
3. SCOPE
These information deficiencies apply to concentration and/or dissemina-
tion of pathogens from municipal sewage treated effluents, from .landf.'ill
operations, from resource recovery systems, and from animal wast-es. In-
formation from these sources is also lacking about the health of the:
operators who are directly working with the materials and proces ses ,
and of the health or disease implications for the public at largo, for
domestic animals, and for game and wildlife; furthermore, concentration
and/or dissemination of plant pathogens should also be included i'.n the
enquiry.
-------
Bibliography
It was agreed that it would be desirable to set up a central reference
bibliography, and to provide the information as required. That biblio-
graphy is now being compiled from information still being sent in. You
are invited to join in the endeavor by sending in the citations of your
own bibliography, preferably with your annotations or reviews. Sending
your citations is one certain way of ensuring that you will receive
copies of the compilation.*
Research Program - Future research may well be conducted under the
following headings:-
1 . Evidence of morbidity from aerosols that have originated from trea-
te-d effluent wastewaters, established under the criteria we have sug-
gested.
2. Information on the travel of aerosols, and their spread or capture
under field conditions.
3. Information on the survival of pathogens in aerosols, and of their
inactivity after reactivation.
U. Environmental factors that perturb these prime findings.
Only when we have a substantive body of information on at least those
points, will we be able to proceed to the real tasks before us:
5. Evaluation of the risks; and, finally
6. Preparation of recommendations, guidelines, and model codes.
A projjram of this magnitude can only be accomplished by numerous teams
working together to an agreed schedule. It is our hope that the infor-
mation, flow into and from this study group will encourage that co-ordi-
nation ; we welcome your comments.
This puper is a summary of one section of a larger three-part work
presently in preparation. At this stage it must be regarded as an in-
terim clraft, which we have presented today for your comments and im-
provements.
Please send information to Dr. Geoffrey Stanford, School of Public
He.alth,, P. 0. Box 20186, Astrodome Station, Houston, Texas 77025,
U.t».A.
62
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1. Sepp, Endel, The Use of Sewage for Irrigation - A Literature Review
Bureau of Sanitary Engineering, Dept. Pub. Health, State of Cali-
fornia (19T1).
2. Hawley, H. Bradford, Morin, David P., Geraghty, Margaret E., Tomkow
Jean, Phillips, C. Alan, Coxsackie Virus B Epidemic at a Boy's
Summer Camp., JAMA 226: 1 (October 1, 1973) 33-36.
3. e.g., Braunschweig, Germany; where after some years on a local
scale, the system has been extended to a regional program.
U. Wilson, Harold. Some Risks of Transmission of Disease During the
Treatment, Disposal, and Utilization of Sewage, Sewage Effluent,
and Sewage Sludge. J. Proc. Inst. Sew. Purif. , 19kh. 21^-239.
5. Melbourne, Australia.
6. Lund E. (1971) Observations on the Virus Binding Capacity of'Sludge,
Proc. of the 5th Int. Water Pollut. Res. Conf. I-2U, 1-5.
London.
7. Lund, E. (1973) On the Isolation of Virus from Sewage Treatment
Plant Sludges. Water Research 7, 863-871.
8. Bruvold, William C. and Ward, Paul C. Using Reclaimed Wastewater -
Public Opinion JWPCF hk:9 (September, 1972). 1691-1696.
9. e.g., Texas State Department of Health. In November, 1973, 123
Texas sewage plants were supplying effluent treated water for irri-
gation, and sludges were supplied for fertilizer dry from. 25^
plants, liquid from 12, and by commercial sale from 10.
10. e.g. , California State Department of Health; Statewide Standards
for the Safe Direct Use of Reclaimed Wastewater for Irrigation and
Recreational Impoundments; California Administrative Code, Title 17;
Department of Public Health, Berkeley, California.
11. Lewis Clarke, landscape architect; personal communication.
12. e.g., Merz, Robert C., 1955. A Survey of Direct Utilization of
Waste Waters. Calif. State Water Poll. Control Bd. Publn. Ho. 12.
and Merz, Robert C. , 1956. Report on Continued Study of Waste
Water Reclamation and Utilization. Calif. State Water Poll. Con-
trol Bd. Publn. Ho. 15.
13. Dixon , Fritz R. and McCabe, Leland J. Health Aspects of Waste-
water Treatment, JWPCF 36:8 (August, 196U). 98^.989.
63
-------
lA. e.g., Mission Bay Park, San Diego, California.
15. e.g., Vinton Bacon, Metropolitan Sanitary District of Greater
Chicago, 1970; personal communication.
l6. Committee on Sewage Disposal (Am. Pub. Health Assoc., Pub. Health
Eng. Sect.) The Utilization of Sewage Sludge as Fertilizer,
Sewage Works Journal 9:6 (Nov. 1937) pp. 861-912.
17. e.g., Milorganite, sold retail by the City of Milwaukee, Wisconsin.
18. e.g., City of Houston, Texas.
19. 1973, personal communication.
20. Wright, T. J., Greene, V. W., Paulus, H. J., Viable Microorganisms
in an Urban Atmosphere, J. Air Pollution Control Assoc. 19:337
(1969).
21. Center for Disease Control: Foodborne Outbreaks, Annual Summary
1972; DHEW #CDC 7^-8l85; November, 1973.
22. Akesson, Norman B.; Yates, V7esley E., and Christensen, Paul, 1971.
Aerial Dispersion of Pesticide Chemicals of Known Emissions,
Particle Size and Weather Conditions.
23. Gregory, P. H., Microbiology of the Atmosphere, New York, 1973.
2U. "Plotkin, Stanley and Katz, Michael. "Minimal Infective Doses of
Viruses for Man by the Oral Route." IN Transmission of Viruses
by the Water Route (G. Berg., ed.), New York, 1966, 151-166.
25. Hatch, T., Pulmonary Deposition and Retention of Aerosols, New
York, 196U.
26. Joint Resolution of the Water Pollution Control Federation, and
the American Water Works Association, November 7, 1973.
-------
PERMISSIBLE LEVELS OF HEAVY METALS IN SECONDARY EFFLUENT FOR USE
IN A COMBINED SEWAGE TREATMENT-MARINE AQUACULTURE SYSTEM I.
MONITORING DURING PILOT OPERATION*
by
W. B. Kerfoot and S. A. Jacobs
Domestic wastewater inherently contains a higher load of metals
than the original source water due to the treatment of water for algae
control, leeching from pipes, and solutes added during household
use1*2. While nutrient-rich secondarily-treated wastewater can serve
as a fertilizer for aquaculture of commercially valuable algae and
shellfish3»^>5> excessive levels of metals in solution may be toxic
to the cultured organisms, accumulate in the meat of food products to
an extent to pose a danger to public health if consumed, or impair
the visual appeal and taste of the meat. The question arises, does
the elevated metal content of a secondarily-treated wastewater render
it unsuitable for aquacultural purposes? If not, what levels of
heavy metals in the effluent are acceptable for aquacultural usage
since domestic effluents from industrialized regions tend to contain
more elevated concentrations than those from rural sources^?
Within this paper we address the first question, citing the
levels of cadmium, lead, copper, zinc, chromium, and nickel observed
in the effluent, seawater, and oysters during operation of a pilot
sewage treatment-marine aquaculture system. Guidelines for acceptable
levels of metal in the effluent for use in an aquaculture system are
developed later in the companion paper.
THE WASTEWATER TREATMENT-MARINE AQUACULTURE SYSTEM
Secondarily-treated wastewater, diluted with seawater, makes an
excellent medium for growing marine phytoplankton. The phytoplankton
is, in turn, removed from the water by filter-feeding shellfish, con-
verting the organically-fixed nutrients into valuable protein (figure
1). Nutrients regenerated directly from the excretion or indirectly
from faecal deposits of the shellfish are removed by the growth of
macroscopic algae in tanks before discharge of the effluent to coastal
water.
3
As described in detail previously by Ryther et al. and Goldman
et^ jil^7, the system has several distinct advantages over previous
*
Contribution No. 3305 of the Woods Hole Oceanographic Institution. c\i
This study was supported by NSF(RANN) 32140 and the Woods Hole °
Oceanographic Institution.
65
-------
algal processes for nutrient stripping. First, removal of algal bio-
mass is accomplished by using the algae as a food source rather than
an end product which must be disposed of. Secondly, the herbivores
represent a highly desirable, and economically important protein
source. Thirdly, the process lends itself to the development of a
multi-component food-chain system useful for the production of many
commercially valuable food crops. For instance, a town of 50,000
people with a 126 acre aquaculture-sewage treatment system could raise
an annual crop of over 900 tons of oyster meat, worth in today's market
upwards of 5 million dollars as a luxury table oyster or 1 million
dollars as canned or frozen products.
The design of the system is fairly simple. Effluent is added to
filtered seawater at a ratio of 1:4 (figure 1). Phytoplankton cul-
tured in this mixture flows into tanks of shellfish where it mixes
with diluting seawater at a concentration of 1 part culture to 19 parts
100/i-filtered seawater. The remaining water flows full strength
into the macroscopic algae tanks and then, finally, is returned to
the coastal waters. Other ratios of effluent:seawater ranging from
1:10 to 1:0.5 and ratios of algae culture:seawater ranging from 1:1
to 1:10 have been used. The above conditions applied to experiments
performed during summer 1972 and winter 1973.
During the operation of the pilot project, the dominant species
in the culture vats were always diatoms - usually either Phaeodactylum
tricornutum or Chaetoceros simplex, often interspersed with smaller
numbers of assorted diatoms, flagellates, and green algae. The oyster
culture system was a 760 liter rectangular tank (265 cm long, 62 cm
wide, 53 cm high), constructed of fiber glass-coated wood. The
oysters, numbering 500 in total, were positioned on trays of Vexar
mesh. Overflow from a standpipe in the shellfish tanks was introduced
into another rectangular wooden tank which held seaweed (Chondrus
crispus and Ulva lactuca) for final removal of nutrients from the water
before discharge.
TRACE METALS IN THE SYSTEM
The metals selected for this study are capable of being concen-
trated in the tissue of marine organisms: cadmium, which has been
shown to cause kidney failure in humans and the "Itai-Itai disease"
if present in sufficient quantities in consumed products ; lead, which
may cause encepholopathy, anemia, and renal damage if present in high
concentrations in meat^; copper, which may be toxic to algae10, lead
to discoloring and bitterness of oysters11, or may be toxic to human
consumers if present in high concentration in the meat12; zinc, which
may interfere with growth or organisms in the culture system if
present in high enough concentrations10, but does not present a danger
to consumers1-*; chromium, which may be carcinogenic at elevated con-
centrations in foodiS, and nickel, which may be toxic to algae and
but whose effect on consumers of meat is uncertain".
66
-------
'
I
FILTERED SEAWATER 80%
'^
SECONDARY EFFLUENT 20%
DAILY BATCH PHYTOPLANKTON
HARVEST
SECONDARY EFFLUENT
SUPPLY TANK
MARINE PHYTOPLANKTON
CULTURE SYSTEM
FILTERED SEAWATER- 95%
SEAWEED GROWTH
TANK
SHELLFISH TANK
FINAL
EFFLUENT TO COASTAL
WATER OUTFALL
PHYTOPLANKTON
FEED TANK
PHYTOPLANKTON FOOD-5%
FIG. 1 SCHEMATIC FLOW DIAGRAM OF A COMBINED NUTRIENT REMOVAL-MARINE AQUACULTURE SYSTEM
-------
PROCEDURE
The object of the study was to determine the metal content of
the secondary effluent, the dilution expected by seawater in the
system, and the rate of accumulation of metal by the (cultured)
oysters. Oysters have frequently been used as indicators of metal
pollution because of their higher sensitivity to elevated levels of
many heavy metals^,16^ compared to other species of shellfish*?. The
rate of increase of metal, if present, will indicate the final content
of metal expected at the termination of culture, important for public
health considerations.
Determination of the content of metal dissolved in the secondary
effluent was performed by direct atomic absorption when the metal con-
tent was sufficiently high, as often in the case of copper and zinc.
Analyses of other elements in effluent and in seawater were done by
the APDC-MIBK extraction procedure used by Brewer, Spencer and Smith18.
With effluent, more MIBK must be used because of its increased solu-
bility, as specified in the EPA standard methods manual19.
The oysters (Crassostrea virginica) came directly from the shell-
fish tanks which held 500 individuals. Each tank received daily 595
jag carbon/liter of algae contained in 500 liters of culture20. To
establish the initial concentration of metal in the oysters, eight
individuals were removed at the beginning of the experimental period
and analyzed. Later samples of six individuals each were taken from
the shellfish tanks after 45 days, 78 days, and 102 days of exposure
to the sewage-grown algae.
For wet-ashing, the entire body of an oyster was rinsed with dis-
tilled water, weighed and transferred to an aqua-regia-washed 125 ml
Erlenmeyer flask. Digestion was performed by adding 10 ml of concen-
trated nitric acid to the sample, boiling to dryness, and allowing to
cool. Then 10 ml of 30% hydrogen peroxide was added and the sample
re-dissolved in a 57. nitric acid solution made up of a standard volume
for analysis by atomic absorption.
All analyses were done on a Jarrel-Ash Model 800 Atomic Ab-
sorption Spectrophototneter (AAS), a dual-beam channel instrument with
recorder printout. The most sensitive channel was set to the principal
analytical wavelength. The second channel was set to a nearby non-
absorbing wavelength, using the "B/A" mode of the instrument21, to
provide correction for matrix effects and background scattering.
Efficiency of the digestion procedure was evaluated by determining
recovery and reproducibility. Known portions of metal were added to
fifteen five gram amounts of homogenized oyster tissue, with five un-
treated samples of 5 grams each used for background levels. The metals
were added as zinc acetate, copper sulfate, nickel sulfate, cadmium
iodide, lead acetate, and potassium chroroate. Recoveries of Zn, Cu,
Ni, Cd, Pb, and Cr were 97±2%, 95±5%, 98±3%, 98±5%, 96±2%, and 99±3%.
68
-------
RESULTS
Chemical analysis did not reveal high concentrations of poten-
tially dangerous metals in the effluent obtained from the Otis Air
Force Base Sewage Treatment Plant and used in culture (table 1). The
metal content generally ran less than considered average for secon-
dary effluent", although the copper concentration infrequently rose
above .11 ug/ml (ppm) and occasionally above the range expected for
average effluent. With the exception of nickel, the concentration of
each metal in the effluent generally ran 8 to 150 times the level in
the seawater used for dilution. The nickel content of seawater was
similar to that of the Otis effluent.
The concentration of metal in the cultured oysters showed a con-
tinual decline from the 45th day of culture onwards (figure 2). The
apparent increase in concentration during the first 45 days of cul-
ture is probably due to our choice of large individuals for the back-
ground metal determinations. The later random removal of individuals
being monitored for growth indicated that as weight increased, the
metal content decreased. Although not premeditated, the mean weight
of the samples taken at the termination of culture was similar to the
mean of the original samples taken for background (5.68 to 5.18 gms
wet meat weight, respectively). A t-test of the difference between
mean concentrations at the start of exposure and at the finish re-
vealed no significant differences. With zinc, copper, and lead the
total content of metal per individual remained essentially constant,
despite changes in weight, while a slight decrease in total metal con-
tent occurred with cadmium, chromium, and nickel. Overall, the
oysters in the tanks showed slightly over a 50% increase in average
weight during the monitoring period, from an initial dry meat weight
of .425 gms to a final .676 gms20.
The original and final concentrations of metal in the meat are
also compared with alert levels discussed by the Massachusetts Division
of Water Pollution Control16. The alert level concept was developed
to be used as a guide or indicator of metal pollution in shellfish
growing waters and was not intended to reflect the toxicity of metals
contained in the shellfish. Only in the case of lead was any indica-
tion of contamination given, the baseline value being above the pro-
posed state alert level (table 3), presumably occurring before ex-
posure to sewage-grown algae.
DISCUSSION
Lack of accumulation of metal can be traced to three factors:
1) Dilution of the effluent by seawater, 2) the relatively low metal
content of the Otis effluent, and 3) the increased growth of the
oysters. Dilution plays by far the most important role of these
factors although the mixing of seawater and effluent was determined
69
-------
Table 1. Constituents of Otis secondary effluent compared
with the Washington report "Average" effluent^
Material
Concentration (ppm)
Secondary effluent
Washington
Report
Otis
Plant
Organic content (particulate carbon)
(dissolved organic)
Nitrogen (total as N)
Ammonia (as N)
Nitrite (as N)
Nitrate (as N)
Phosphorus
Phosphate phosphorus (as P)
Trace metals
Chromium
Copper
Lead
Zinc
Cadmium
Nickel
25
10-30
20
10
.02-.14
.07-.14
.01-.03
.20-.44
.01-.03
.03-.20
12-30
40
17.6
15.2
.4
2.0
8.2
.003-.040
.025-.300
.005-.020
.035-.095
.0005-.0023
.0005-.010
70
-------
2OOO
20
40
60
8O
1OO
0
- ZINC
i
16OO
12OO-
8OO*
g
•S* 4OO
r
i
i.
2OO
16O
*
K
5O
0
2O
15
10
8
6
4
COPPER
LEAD
MEAN WEIGHT
2O 40 6O 8O
TIME-DAYS OF CULTURE
2O
CADMIUM
4O
60
80
100
CHROMIUM
NICKEL
MEAN GROWTH
3 b
i
31K
•t
100 2O 4O 60 8O
TIME-DAYS OF CULTURE
0
100
Fig 2 Metal concentration //? tissue of oysters during 1O2 Days of
culture. Mean met a/ concentration in mg/gm (ppm) wet
weight and one standard deviation are included. The mean
weight of the individual oysters sampled and their growth,
as mean increase of length of shell is also shown
77
-------
by culture process and not originally intended for lessening metal
contamination. The dilution of effluent to seawater for the algae
culture mixture was based on earlier experimental results which indi-
cated that yields of algae were roughly proportional to the concentra-
tion of sewage effluent in the enriched seawater medium up to concen-
trations of about 20% sewage and 80% seawater^. The dilution of cul-
ture mixture with 20 parts seawater as it is delivered to the shellfish
tanks was to provide a sufficient volume flow of seawater to maintain
a high level of dissolved oxygen to the shellfish-*.
With a very low background metal content, seawater substantially
dilutes the original metal levels in the effluent (table 2). For
comparison, the amounts of dissolved metal often introduced inadver-
tently as contaminants in media prepared for algae culture with
artificial seawater and nutrients from analytical grade reagents, is
equal to or greater than the levels of metals present in the algae
cultured prepared from Otis effluent^.
A total dilution of 1:200 occurs before contact of the effluent
with shellfish. This is almost sufficient to reduce the levels of
metals in the effluent to the background levels in the seawater (table
2). Even with the element copper, which at times reaches a high con-
centration in the effluent (300 jag/liter), the maximum level which
occurs in water reaching the shellfish is 12 ^ig/liter, just slightly
above the maximum level of copper (9 ,ug/liter) recorded in the sea-
water used for culture.
Secondly, the metal content of the Otis effluent, resembling
domestic wastewater in character rather than an industrial source,
was not particularly elevated. Only copper, of all the elements
studied, was as high or higher than the concentrations expected in
average effluent as assumed in the Washington report^ while the
chromium and lead content occasionally fell within the average range,
zinc, cadmium, and nickel at their highest observed levels were less
than the minimum level anticipated in average effluent.
Finally, the increased rate of growth of the oysters probably
contributed to the observed decline of metal content in the latter
days of culture. For instance, despite the change in lead concen-
tration from 4.2 + .2 >ig/gm wet weight initially to 10.1 + .5 at 45
days, 5.4 +2.2 at 80 days, and 4.1 + 2.2 at 102 days, the total lead
content of the individual oysters, was relatively constant at 21.6 +
12.0 ug, 20.6 + 14.8, 19.0 ± 13.0, and 24 ± 12.6, respectively.
Copper, and to a lesser extent zinc showed the same constancy of in-
dividual metal content despite fluctuations in weight and concentra-
tion of metal. In contrast, with cadmium, which previous studies had
indicated a very slow loss, if any, within 30 days following exposure
to a high concentration24> some loss did definitely occur after 102
days of culture that was not due to weight change.
72
-------
Table 2. Concentration of metals in solution in secondary effluent, seawater,
and subsequent dilution in algae culture and shellfish tanks. For comparison,
the content of metal found in synthetic algae growth media is indicated next
to that expected in the culture mixture
Metal concentration jug/liter (ppb)
Element
Zn
Cu
Cd
Cr
Pb
Ni
Otis
Effluent
35-95
25-300
.5-2.3
3-40
5-20
.5-10
Seawater
5-12
2-9
.06-. 08
.3-. 5
.02-. 8
1-5
Algae
Culture Media
11-28
7-67
.15-. 52
.9-8.5
1.0-4.6
.9-6.0
Ri ley's
Media
150
34
nd
12
31
8
Shellfish
Tanks
5-16
2-12
.06-. 10
.3-. 9
.07-1.0
1-5
-------
As concentration of a metal in tissue is a ratio between the
total metal content and total weight of the organism, even though a
steady increase in total metal content may occur, if the rate of in-
crease in weight is greater, the concentration of metal in the tissue
will decrease. For example, the mean total copper content of in-
dividual oysters raised from 375, to 304, to 433, and finally to 438
ug on the successive days of sampling while the concentration in
ug/gm wet weight (ppm) declined noticeably from the 45 to the 102 day.
In the aquaculture system, where growth of the shellfish is acceler-
ated, new tissue is added at a higher rate than that observed normally,
serving as a mechanism to dilute the concentration of some metals which
may continue to be accumulated at a regular rate regardless of growth.
The 102-day study indicates that oysters can be cultured with
the use of secondary effluent as a substitute fertilizer without
raising the danger of metal contamination. While other potential
contaminants, including pathogens and organic compounds, need further
investigation to evaluate the advisability of substituting secondary
effluent for artificial media in aquaculture, the initial results
suggest that the inherent elevated metal concentrations in domestic
wastewater do not appear to pose a threat to shellfish culture if
effluent of a principally domestic source is used.
-------
Table 3. Accumulation of metals in oysters of pilot
tertiary treatment-aquaculture system fed sewage-
grown algae for 102 days. Mean metal concentration
and one standard deviation are indicated
Metal content (ppm wet weight)
Element
Zn
Cu
Cd
Cr
Pb
Ni
Initial
818 + 446
72 + 18
2.00 + .30
.10 + .04
4.2 + .2
.29 + .13
Final
743 + 182
81 ± 18
1.30 + .26
.04 + .02
3.6 + 2.5
.21 + .10
State Alert
Level16
2000
175
3.5
2.0
2.0
Unspecified
75
-------
REFERENCES
1. Muskegon County Board and Department of Public Works. Engineer-
ing feasibility demonstration study for Muskegon County, Michigan
wastewater treatment-irrigation system, Program 11010FMU, Federal
Water Quality Administration, September, 1970.
2. Young, D. R. , C-S. Young and G. E. Hlauka. In Cycling and Con-
trol of Metals; Proceedings of an Environmental Resources Con-
ference. National Environmental Research Center, Cincinnati,
1973, p. 21.
3. Ryther, J. H., W. H. Dunstan, K. R. Tenore and J. E. Huguenin.
Bioscience 22(3): 144, 1972.
4. Dunstan, W. M. and D, W. Menzel. Continuous cultures of natural
populations of phytoplankton in dilute, treated sewage effluent.
Limnol. Oceanogr. .16(4):623-632, July, 1971.
5. Dunstan, W. M. and K. R. Tenore. Intensive outdoor culture of
marine phytoplankton enriched with treated sewage effluent.
Jour. Aquaculture 1.: 181-192, 1972.
6. Jacobs, S. A. Some measurements of heavy metal content of
sewage effluent and sludge. In The Use of Flowing Biological
Systems in Aquaculture, Sewage Treatment, Pollution Assay, and
Food-Chain Studies. J. H. Ryther, edit., Technical Report WHOI
73-2, December, 1972.
7. Goldman, J. C., K. R. Tenore, J. H. Ryther and N. Corwin. In-
organic nitrogen removal in a combined tertiary treatment-marine
aquaculture system. I. Removal efficiencies. Water Research,
In Press.
8. Kjellstrom, T., L. Friberg, G. Nordberg and M. Piscator. In
Cadmium in the Environment. CRC Press, Cleveland, Ohio, 1971,
p. 140.
9. Kehoe, R. A. Metabolism of lead under abnormal conditions.
Archives of Environmental Health 8:235-243, February, 1964.
10. Bryan, C. W. The effects of heavy metals (other than mercury)
on marine and estuarine organisms. Proc. R. Soc. Lond. Ser. B
177:389-410, 1971.
11. Roosenburg, W. H. Greening and copper accumulation in the
American oyster, Crassostrea virginica, in the vicinity of a
steam electric generating station. Chesapeake Science 10(3&4):
241-252, Sept.-Dec., 1969.
76
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12. Pringle, B. H. and C. N. Shuster. A Guide to Trace Metal Levels
in Shellfish. Shellfish Sanitation Tech. Rept. USDHEW. Public
Health Service, 1967, 19 p.
13. Browning, E. Toxicity of Industrial Metals, Second Edition.
Appleton-Century-Crofts, Butterworth & Co. (Publishers) Ltd.,
London, 1969.
14. Jones, J. R. E. Fish and Water Pollution. Butterworths,
London, England, 1964.
15. Huggett, R. J., M. E. Bender and H. D. Slone. Utilizing metal
concentration relationships in the eastern oyster (Crassos_tr_ea
virginica) to detect heavy metal pollution. Water Research 7_:
451-460, 1973.
16. Isaac, R. A. and J, Delaney. Toxic Element Survey. Progress
Report No. 1, Massachusetts Water Resources Commission, Division
of Water Pollution Control, Publication No. 6108, 1972, 25 p.
17. Pringle, B. H., D. E. Hissong, E. L. Katz and S. T. Molawk.
Trace metal accumulation by estuarine mollusks. J. Sanit. Eng.
Div., Amer. Soc. Civ. Engrs. 94:455-475, June, 1968.
18. Brewer, P. B., D. W. Spencer and C. L. Smith. Determination of
trace metals in seawater by atomic absorption spectrophotometry.
Atomic Absorption Spectroscopy, ASTM STP 443:70-77, 1969.
19. Methods for Chemical Analysis of Water and Wastes, Environmental
Protection Agency, Analytical Quality Control Laboratory, Cin-
cinnati, Ohio, 1971.
20. Tenore, K. R., J. C. Goldman and J. P. Clarner. The bio-
energetics of the oyster, clam, and mussel in an aquaculture
food chain. J. Exp. Biol. and Ecol. 12:157-162, 1973.
21. Jarrel-Ash. Atomic Absorption Methods Manual, vol. 1, Jarrell-
Ash Corp., Waltham, Mass., 1970.
22. Driver, C. H., B. F. Hratfiord, D. E. Spyridakis, E. B. Welch
and D. D. Woolridge. Assessment of the Effectiveness and
Effects of Land Disposal Methodologies of Waste Water Manage-
ment. Seattle, Washington, R. F. Christman, Project Coordinator,
Final Report, Contract No. DACW 73-73-C-0041, U.S. Army Corp.
of Engineers, January, 1972.
23. Riley, J. P. and I. Roth. The distribution of trace elements in
some species of phytoplankton grown in culture. Jour. Mar.
Biol. Ass. U.K. 51(l):63-72, 1971.
77
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24. Kerfoot, W. B. and S. A. Jacobs. Cadmium accrual in a combined
wastewater treatment-aquaculture system. In Proceedings of the
First Annual NSF Trace Contaminants Conference, W. Fulkerson,
edit., Oak Ridge National Laboratories, Oak Ridge, Tenn., 1973.
78
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PERMISSIBLE LEYSLS OF HEAVY METALS IN SECONDARY EFFLUENT
FOR USE IN A COMBINED SEWAGE TREATMENT-MARINE AQUACULTURE
SYSTEM II. DEVELOPMENT 0? GUIDELINES BY METHOD OF ADDITIONS*
by
W. B. Kerfoot and G. A. Redmann
Shellfish can be cultured on algae raised with
secondarily-treated wastewater substituted for artificial
nutrients without any apparent accumulation of toxic metals
in their tissues^. The effluent used was found to be rela-
tively low in background concentrations of metals, similar
to principally domestic sources using anaerobic treatment
procedures. In many of our industrialized cities, however,
the effluent from a sewage treatment plant contains an array
of metals at substantially higher levels than that received
from solely domestic sources2»3. Rather than test each
source individually, it would be worthwhile to develop
guidelines which serve to define suitable sources of
effluent for aquacultural purposes. Within this paper we
attempt to determine the concentrations of six metals, zinc
(Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr),
and nickel (Ni) that are permissible in a combined sewage
treatment-marine aquaculture system.
TERTIARY TREATMENT-MARINE AQUACULTURE
Nutrient-laden secondary effluent can become a nuisance
when discharged into coastal waters, stimulating algae blooms
with foul odor and contaminating shellfish beds. On the
other hand, careful control of the quality of the effluent
to assure a pathogen-free high nutrient source will provide
a potentially valuable resource in the face of diminishing
supplies of food and artificial fertilizer. Secondarily
treated wastewater, diluted with seawater, makes an excellent
medium for growing marine phytoplankton. The phytoplankton
is, in turn, removed from the water by filter-feeding shell-
fish, converting the organically-fixed nutrients into
valuable protein.
During the past three years, a prototype system of
tertiary treatment-marine aquaculture has been in operation
Contribution No. 3297 of the Woods Hole Oceanographic
Institution. This study was supported by NSF (RANN) 32140
and the Woods Hole Oceanographic Institution.
79
-------
at Woods Hole Oceanographic Institution. Various designs'
have been engineered to culture marine phytoplankton and
subsequantly raise shellfish, with any nutrients regenerated
by faecal material of the shellfish being removed by the
growth of macroscopic algae in tanks before discharge to
coastal waters^»5*°.
A more detailed explanation of the system employed
during the summer of 1972, upon which these experiments are
based, is explained in the previous paper (Kerfoot and
Jacobs)''. Effluent was added to filtered seawater at a
ratio of 1 :if. Phytoplankton cultured in this mixture
together with diluting seawater was then introduced into
tanks of shellfish at a concentration of one part culture to
19 parts 100 u-filtered seawater. At this dilution, the
carbon content of the seawater, an indicator of the food
value to the shellfish, is raised from a normal level of
100 ug carbon/liter to roughly 600 ug carbon/liter. More
than 80/0 of the phytoplankton fed to the shellfish originates
from nutrients provided by the effluent, and about 1% of the
water reaching the shellfish is derived from the secondary
effluent.
PATHWAYS OF CONTAMINATION AND TOXICITY
When metals are introduced with the effluent, the
algae nay accumulate metallic ions directly from solution by
absorption (here indistinguishable from adsorption). Then
the algae mixture flows into the herbivore tanks, where the
shellfish may directly absorb ions from the considerably
diluted culture solution or through ingestion of contamin-
ated phytoplankton and detritus (figure 1). In this study
the algae cultured was Phaeodactylum trieornutum, a. pennate
diatom commonly occurring during normal operation of the
aquaculture system. The American oyster (Crassostrea
vir^inica) was chosen as the shellfish species because of
its potential economic value as a luxury food and the need
to assess its sensitivity to metals which may be added in
the effluent.
The sensitivity of Phaeodactylum tricornutum to change
in metallic ion concentrations is well recognized.
Previously Hayward has shown that P. tricornutum initially
absorbs zinc rapidly, but the concentration in cells
decreases as their numbers increase?. RLley and Roth found
that P. tricornutum under similar conditions accumulated
less tThan half the amount of metals that Hayward found°.
Nuzzi reported that mercury levels as low as .06 ug/liter
(ppb) were inhibitory to P. tricornutum, and that morpho-
logical abnormalities increased~with mercury concentration,
80
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METAL
IN EFFLUENT
SEA WATER
ABSORPTION
INGESTION
ALGAE
INGESTION
SHELLFISH
MAN
ELIMINATION
Figure 1. Pathways of contamination in the treatraent-
aquaculture system.
-------
the normally biradiate cells becoming highly vacuolated and
assuming an ovoid state9,
Hannon and Patouillet noted that growth inhibition by
a toxicant varies inversely with the concentration of
nutrients available. They found that the exponential
growth of P. tricornutura was not affected by exposure to
0.1 ppm lead or copper. Exposure to 1.0 lead had no effect,
while 1.0 ppm copner inhibited the growth rate to less than
half that of controls10.
The ability of the American oyster to accumulate trace
metals from solution is also well-documented. Soosenberg
founr that greening of oysters could be traced to excessive
uptake of copper due to thermal effluent from power plant
activity'1. Pringle et. al. surveyed the average trace
metal levels in shellfish from the Atlantic and Pacific
coasts and also carried out studies on metal uptake and
concentration in a simulated natural system12. They
reported that lead was absorbed by C. virginica in direct
proportion to concentration in seawater, accumulating four
ir.igrograms of Pb per gram v/et meat per day when exposed
continuously to 0.2 ppm in seawater. Average metal back-
grounds in Atlantic oysters were: zinc, 14.28 ppm; copper,
92 ppm; lead, 0.47 PPia; nickel, 0.19 PP^J chromium, 0.40 ppm;
and cadmium, 3.10 ppm. Kerfoot and Jacobs found linear
cadmium uptake by C virginica from seawater in a deliber-
ately contaminated sewage treatment-aquaculture system'-?.
The observed rate of uptake of cadmium (in ug/gm/day) was
17.8 times the concentration of cadmium in solution (in
ppm-ug/al). With effluent as the source of cadmium, the
principal means of uptake was through the ingested algae.
MATERIALS AND METHODS
Scale models of a sewage treatnent-aquaculture system
were constructed in the seawater laboratory at V.'oods Hole
Oceanosraphic Institution (figure 2). Two-liter erlensiyer
flasks were filled daily with a 4:1. mixture of one micron
filtered seawater and filtered (.45 u) secondary effluent
from the Otis Air Force ?iase sewage treatment plant.
Effluent containing 10 ppm, 3 ppra, .3 PPE» -and .03 ppm
equal concentrations of 3n, Cu, Pb, ITi, Cd, Cr was added to
the flasks v/ith one flask receiving unsupplemented effluent
as a control. The effluent-seav/ater mixture, as media, was
dripped continually at 1.5 ir.l per minute or 2 liters per day
into'4-liter flasks containing cultures of the diatom
SDecies. Water containing the cultured diatoms flowed at
the same rate from the culture flasks into trays holding
82
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INFLOW COOLANT
WATER
FILTERED-7
COMPRESSED AIR
CONTINUOUS
CULTURE
FLASK
CULTURE MEDIA INLET
THERMOMETER
OUTFLOW COOLANT WATER
SEAWATER INLET
COOLANT
CYLINDER
CULTURE
MEDIA
INLET
BAG
FILTER
.OVERFLOW
O WASTE
BUBBLER
STIRRING
BAR
MAGNETIC STIRRER
CULTURE MIXTURE
SEAWATER INLET
WATER
OUTFLOW
CONSTANT HEAD>
BOTTLE
OUTFLOW TO SHELLFISH TANK
OUTFLOW CULTURE MIXTURE
AIR INLET
SHELLFISH TANK'
Figure 2. Scale rrodel treatment-aquaculture sy::ter
83
-------
oysters in two liters of water, where it was mixed with
25 nl per minute of filtered seawater supplied from a
constant head tank.
The culture flasks were illuminated by a bank of
fluorescent bulbs providing approximately 500 ft-candles,
stirred by magnetic stirring bars, and maintained at
20* ±2* C by seav/ater flowing through glass tubing inserted
into the culture mixture. The culture also received air,
cleaned by a water trap and activated carbon, bubbled
continually through the mixture from an inserted pipette.
Four 20 liter plastic carboys were filled with ,/4-5 u-filtered
secondary effluent. The stock solutions were made up to
10.0, 3.0, 0.3» and 0.03 PP& (nig/1) with zinc from zinc
acetate (Zn fc^^Og 3-2H20) , copper from copper sulfate
( CuS04'5H20), cadmium from cadmium iodide (Cdl2), lead from
lead acetate (PbfC2H30p3»3H20), chromium from potassium
chromate (J^CrOO, and nickel from nickel sulfate (NiSO^.
6H£0). Each day" of the study, 400 ml of effluent or metal-
enriched effluent from the four carboys v/as mixed with 1600
ml of one micron-filtered seawater in the 2 liter media
flasks which supplied each algae culture flask.
Fluorimeter readings were taken daily on 10 ml samples
of the algae cultures. Weekly samples were taken of the
oysters and frozen after being placed in clean seawater to
void their intestinal t^cts. Samples of the seawater and
effluent were removed periodically during the study for
analysis of netal content. At the termination of the exper-
iment, two liter samples of the algae were removed from the
culture, centrifuged, and dried on nuclepore filters for
metal analysis.
The procedure employed for wet-ashing was the same as
that reported by Kerfoot and Jacobs*»'-5. The entire body
of an oyster was removed from the shell, rinsed with
distilled water, weighed, and transferred to aqua-regia
washed 125 ml erlenmyer flasks. Digestion was performed by
adding 10 ml of concentrated nitric acid to the sample. The
sample was allowed to stand in acid for 12 hours at room
temperature, heated gently close to dryness, and allowed to
cool. Then 10 ml of J>Q% hydrogen peroxide was added and the
sample heated to dryness. After cooling, the sample was
redissolved in a 5% nitric acid solution, made up of a
standard volume for analysis, and aspirated directly into
the atomic absorption spectrophotometer. All analyses were
done on a Jarrell-Ash Model 800 Atomic Absorption Spectro-
photometer, using a nearby non-absorbing line for background
absorption.
K
-------
Phytoplankton samples on the filters were added to
10 ml of 56^ nitric acid in individual 20 ml test tubes.
After 48 hours digestion, the solution was filtered through
3 u nuclepore filters into 20 ml centrifuge tubes for direct
aspiration into the atomic absorption spectrophotometer.
Metal analysis of the seawater and effluent was
performed using the techniques described previously by
Kerfoot and Jacobs'1 . The samples were filtered and analyzed
directly by atonic absorption or were extracted and analyzed.
For solvent extraction, four 500 ml samples of seawater or
effluent were taken, adjusted to a pH of 2.0, and then
extracted twice with MIBK-APDC. Graded amounts of the
individual metal were added at levels 1,2, and 3 times
higher than anticipated in solution. The concentration in
solution could then be calculated following the method of
additions reported previously by Brewer, Spencer, and
Smith1^. The concentration of background metals in the
effluent used for stock solution was .080, .055, .005» .002,
.010, and .005 PP^ for Zn, Cu, Pb, Cd, Ni, and Cr. Metal
content of the seawater and effluent supplied to the
cultures was reported earlier in the preceding article'.
The culture system was continued for 28 days, during
four of which the effluent media mixture did not flow, for
varying reasons. During this time the algal populations
fluctuated somewhat. To maintain a suitable level, it was
sometimes necessary to supplement the experimental cultures
from stock cultures.
To further define toxic effects of specific metals on
the phytoplankton, four separate experiments were devised
with"batch cultures of P. tricornutum.
First of all, eight 250 ml flasks were prepared by the
addition of SO mis filtered seawater and the effluent stock
solutions, two flasks at each multiple metal concentration.
These were autoclaved and aseptically inoculated with
6 x 105 cells for each flask from a parent culture in
exponential growth. All batch cultures were maintained in a
growth chamber at 1 Ff C, If50 ft-candles, and a light:dark
regime of 13:11. Samples of 1 ml were taken every other
day for 10 days, preserved in Lugel's solution and counted
in either a Speirs-Levy or Palmer-Mahoney counting chamber.
A second series consisting of twenty-four 125 ml flasks
with 50 ml of effluent-seawater media vras prepared with 6
different 5-metal mixtures at 3 concentrations: 5 ppm,
.5 pern, and .05 T>pm metals in the effluent. Each flask was
inoculated with k~.k x 10° cells, producing 8.8 x 10^ cells/
ml. The five-metal solutions were added to the cultures
85
-------
three days after inoculation and samples counted at 5, 8,
and 1? days after inoculation.
A third series to determine relative toxicity of each
metal consisted of eight 250 ml flasks, using 100 ml of the
£4.:"! seawater/effluent media, with six receiving a single
metal at a concentration of .5 ppn in the effluent and two
controls. These were inoculated with 4.4 x 10^ cells.
Sanples were taken 4, 6, and 7 days after inoculation.
A fourth experiment tested the relationship between
cell density and metal inhibition. Six 250 si flasks
holding effluent/seawater media and the 3 ppm mixed metal
solution added to yield a solution concentration of .6 ppm
mixed metals. Then .1, 1.0, and 10.0 ml of inoculum were
added to each pair of flasks, experimental and control.
The cells were sampled and counted 1, 3» and 4 days after
inoculation.
RESULTS
PHYTOPLANKTON TOXICITY
During the course of the study, the levels of algae
varied greatly (figure 3) in the scale-model treatment-
aquaculture systems. The concentration of metals in the
effluent media had little influence on the algae abundance.
The mean density of P. tricornutum in fluorescence units
(fu) was 1060, 1157,"1090, T360, and 11?8 fu, respectively,
for 10.0, 3«0, 0.3» 0.03 and control. Reduction in the
P. tricornutum cultures occurred primarily from predation
by flagellates which passed through the 1.0 micron filters
and grazed down the diatoms. However, the cultures supplied
with higher concentrations of metals in the media exhibited
a more rapid decrease in cell concentration once a drop
began. Also, the cultures receiving 10.0 and 3»0 ppm mixed
metals in their effluent would not recover without supplemen-
tal additions of culture.
With a series of experiments, the relative contribution
of each metal to toxicity was isolated (figure 4). When
£• tricprnutum was cultured in a mixture of all six species
of metals, growth was inhibited when concentrations exceeded
0.3 ppra. In all series with five-metal combinations, all
showed reductions in algae growth in cultures of low density
at .05 ppn and above concentration, except when copper was
removed from the combination (figure 4» middle). The
remaining metals (Zn, Pb, Cd, Cr, and Ni) did not cause a
drop in algae growth until .5 ppra concentration and above in
56
-------
tV.jC
kj 500
Uj 1500
S* 5OO
O 1500-t
10 15 20
TIME(DAYS)
ripure 3. Concentration of phytoplonliton (in fluorescence
units) in culture flaskc durin~ operation of
experimental systcns. The concentration of netals
supplemented in the effluent indicated for each
culture. Arrows mark additions of a 1,^,36 from
stock culture.
87
-------
the effluent. The metals having the principal toxic effect
in the five-metal combinations (minus copper) were Cd and,
to a lesser extent, Ni. When metals were added individually
at .5 ppm concentration in the effluent, copper (Cu),
cadmium (Cd) and nickel (Ni) had a pronounced depressing
effect on algae growth.
From the toxicity series, levels of metal above .3, .5,
• 5» .5» 1.0, and 1.0 ppm, respectively, for Cu, Cd, Ni, Cr,
Pb, and Zn may inhibit algal growth if present in the
effluent and would appear undesirable. The limit of
toxicity found for copper agrees with the report of Mandelli
(1969) that the growth of four different marine diatoms was
inhibited by Cu levels in seawater greater than .05 ppm,
equivalent to .25 ppm Cu in effluent before dilution^?.
Other effects observed on the diatoms were certain
morphological variations. Nuzzi previously described
abnormalities of P. tricornutum induced by mercury9. At
2.0 ppra in the culture media, corresponding to the use of
10.0 ppm mixed metals in the effluent, misshapen chromato-
phores and double nuclei occassionally occurred, as well as
"fat" or foreshortened cells of this normally biradiate
pennate diatom. Somewhat shrunken cells and paired nuclei
were found down to the .3 multiple metal level. A bifurca-
tion at one end of the cell or "fishtail" was often found in
all the cultures, including the controls fed with effluent
unsupplemented with metals.
The influence of cell density on the expression of
toxicity was also apparent (figure 5). Initial cell concen-
trations ranging over three orders of magnitude were added
to media prepared with 3«0 ppni each of the six metals in the
effluent. As the cell concentration rose, the toxicity
decreased. This supports the observation that the high
density of cells being cultured in the aquaculture system
suppresses toxicity until a drop in cell number occurs. The
drop is then accentuated by elevated levels of metal intro-
duced in the effluent. Concentrations of metals exceeding
the toxic levels suggested have an important effect in
decreasing the stability of the culture and its ability to
recover from any slumps in production.
OYSTER TOXICITY
Few oysters died during the operation of the scale
model treatment-aquaculture systems. In no case could the
isolated deaths be attributed to metal concentrations. This
is likely due to the high dilution (lOOx) of effluent
before exposure to the oysters.
88
-------
£
5000
3000
1OOO
30
20
10
0
\O.5ppm SINGLE METALS
|io<
*»*j
a
6 METAL MIXTURE (Zn,Cu,Pb,Cd,Cr,Ni)
• 0.3 ppm
CONTROL
-3.0 ppm
-10.0 ppm
CONTROL
,.05 ppm
5METAL MIXTURE(Zn,Pb,Cd,Cr,Ni)
CONTROL
Cr
Zn
Pb
Ni
Cu
Cd
1 1 1 1 1 1
0
5 IO
TIME (DAYS)
J L
15
Figure k- Effect o
on diaton growth.
89
-------
ABSORPTION BY PHYTOPLANXTON
All of the elements examined were acumula.ted by the
phytoplankton (Table 1). At the highest concentration of
metals added in the effluent (10.0 ppm), equivalent to
2,000 ug/liter since it is diluted five-fold with seawater,
the respective percentages of metal removed from solution
by the algae (.1 gin/liter dry weight) were 59.0, 16.9,
14-9, 9.6, 4.6, and 2.5% for Pb, Zn, Cu, Cd, Ni, and Cr.
Five of the metals remained relatively stable in their
order of magnitude of accumulation, Zn>Cu>Cd>Ni>Cr. However,
lead (Pb) showed a rapid increase in percentage absorption,
ranging from undetectable at .03 ppm concentration to 59/S
of the total lead added in solution from the effluent
concentration of 10.0 ppm.
Of interest to those who may feel that the use of
effluent as a media will cause high background levels of
metal in the cultured algae, the levels of metal in the
controls raised on unsupplemented effluent were generally
lower than those found by Riley and Roth for P. tricornutum
cultured in artificial media containing low levels of trace
elements . Riley and Roth found background levels of 325,
110, 46.3, 6.2, and 4.4 ppm in dry olankton for Zn, Cu, Pb,
Ni, and Cr. We found 120.8, 60.4, 14.6, 12.5, and 4.03 ppm,
respectively, for the same elements. While it should be
kept in mind that Riley and Roth used a dc arc spectro-
graphic technique for analysis, thereby likely analyzing
some additional metal in the silicaceous skeleton of the
diatom, the levels are quite comparable.
ACCUMULATION BY OYSTERS
An increase in the level of metals in the seawater/
effluent media, in general, caused a progressive rise in the
content of metal in the tissue of the oysters being cultured
(figure 6). The points represent the mean metal analyzed
from three or four oysters. The clearest pattern of
accumulation occurred in the elements of lesser affinity for
the oyster tissue, Cr, Ni, and Cd. The concentration of
lead showed a more abrupt rise in level than the other
metals. Cadmium was the only element to show detectable
accumulation at .03 ppra, hut also appeared to saturate at
the highest level (10.0 ppin). Some accumulation of copper
occurred, but no definite uptake of zinc could be discerned.
With zinc and copper, to some extent, the amount absorbed,
even though it may have been large in quantity compared to
the other elements, was obscured by the high background
metal content of the tissue.
90
-------
10'
control
10° :
I04
^ control
x3.
0 1
2 3
TIME (DAYS)
4 5
Figure r^. Tnflunr.ce oe cell density on the expression of
toxicity.
-------
Table 1. Metal content of phytoplankton (utf/gm dry weight).
fle"tal Added
to Effluent
Control
.03
.3
3.0
10.0
5Sn
121*8
113*3
396*13
592*18
3510±290
Cu
60±4
63*8
159*13
634*79
3050*450
Pb
14. 6*. 7
11.2*1.8
57*21
551*127
11,800*1366
Cd
3. 4*. 6
14.2*1.1
124*3
574*104
1930±260
Cr
4.0±1.4
9.7*1.2
48*2
67*15
498*59
Ni
12.5*9.0
2. 6*. 8
• 82±7
161*19
932*53
Background
(Rileynand
Roth)0
325
110
46.3
n.d.
4.4
6.2
n.d. - not determined
-------
^
• ->»
i^h
20
15
10
5
Oi
140
100
60
9n
cU
800
600
<
400
CADMIUM
0
.
--O ^x
^^-^**^*--* ^ ~~&
Q^z^~'^'_&-~^ ""
i-fT^^a*- — • ••IB-- B
I •^
COPPER
\
"-«^z4^rT-Tffl . . -a
. ZINC
-A
L friir^ ,
NICKEL
X
X
x O
X ^,***^
x° °
^X^ A— — — A A
t^...g g £)
5
CHROMIUM /X
.^—^ ^^ ^ rt
^8f^&:°^-'-fa '
' ~ ~ffl IsJ 1=
LEAD
•
^*^
, ^^— ,"
2.0
1.5
1.0
.3
.2
I
3
2
n
0
10 15
0
10 15 20
•-lOOppm in EFFLUENT
o—30ppm in EFFLUENT
A—.3ppm in EFFLUENT
D —,03ppm in EFFLUENT
A—CONTROL
^
MN
vi-'ure
tion or r^etnls :rj oysters.
-------
When the rate of increase was plotted versus the
concentration of metal added in the effluent, a disposition
of uptake similar to that encountered with the phytoplankton
occurred (figure 7). Each point represents the mean rate of
uptake from each series in figure 6. The order of affinity
for the four metals with roughly parallel slopes was Cu>Cd>
Ni>Cr. The rate of uptake of lead (Pb) was over twice the
rate of the other metallic species and undetectable below
3.0 ppm. in the effluent. The abruptness of accumulation
was similar to that observed with the phytoplankton.
Although Cu, Cd, Ni, and Cr exhibited similar rates of
accumulation, the fitted lines all had a slope of less than
1 .0. This indicates that the magnitude of metal uptake
decreases v/ith increasing concentration. A previous detailed
study of cadmium uptake in the treatment-aquaculture system
indicated a relatively fixed ratio of uptake by oysters over
a wide range of metal concentration in both effluent and
seawater as sources. If the combination of metals acted
synergistically, the effect was to impede uptake of metallic
ions at the higher concentrations.
DEFINING A LIMIT
Ideally, the permissible level of a metal should be one
which allows the organisms of the culture system to be free
from acute or chronic toxicity and the food products to be
entirely safe for human consumption. With this in mind a
series of limits were prescribed based on phytoplankton
toxicity, shellfish toxicity, acute toxicity to human
consumers, chronic toxicity to human consumers, and finally,
pollution alert levels. The results are presented in
Table 2.
First of all, the levels of concentrations of metals
which bring about inhibition of growth of Phaeodactylun
tricornutum are listed in the first row. These are based
on the continuous culture and batch culture tests performed
on 6-metal, 5-metal, and single-metal additions in the
effluent as reported in this paper.
Secondly, since no toxic effects of metal additions
were observable with the oysters, the permissible levels
were set at 10 ppm. Further experiments conducted for
periods of time" longer than 28 days may v/ell show chronic
toxic effect as metals accumulate in the tissues of the
oysters. However, no acute effects were noticeable.
-------
10
ki
0.1
.001
Cu
' I I I Hill 1 1 I I I Mil
ki ^^:oi o.i i.o 10
METAL CONCENTRATION IN EFFLUENT
(ppm-/u.g/ml)
V\rt\\TQ 7. ••.-.-Jte of -increase of rr.etal concentration in
tissue as ,T function of the concer.trat j on of
•r.etal added in the effluent.
95
-------
10
CT>
Table 3. Concentrations of metal permissible in solution in
secondary effluent for use in a combined tertiary treatment-
marine aquaculture system using a 1 :if dilution of effluent for
algae media and a 1:19 dilution of algae culture for raising
oysters.
Concentration of Metal in Effluent (ppm)
Based on:
Algae Acute Toxicity
Shellfish Acute Toxicity
Human Acute Toxicity
Human Chronic Toxicity
Pollution Alert Level
Cu
.3
10
.2
N.S.
.36
Cd
.5
10
.080
.010
.012
Ni
.5
10
N.S.
N.S.
.05
Cr
.5
10
>10.0
N.S.
3.0
Pb
1.0
to
N.S.
6.0
2. if
Zn
1.0
10
N.S.
N.S.
N.S.
Suggested Guideline .2 .010 .05 «5 1.0 1.0
N.S. - Hot Specified
-------
A number of the metals studied are known to have toxic
effects when present in food in high amounts. Copper has
been reported to cause bitterness and gastroenteritis when
present in high levels in oysters^'»'". The excessive
copper also imparts a greenish tinge to the oyster meat.
As a result, Roosenburg has suggested a 100 ppm level of
copper in tissue be set for adult oysters for human consump-
tion. Browning has reported that one to two grains of
copper as sulfate will produce severe abdominal pain, vomit-
ing, and diarrhea when ingested17, One grain is equivalent
to a dose of 6.6 mg. For a meal of 40 gm of oyster meat,
equivalent to eight 5-gram oysters, this would represent a.
concentration of 180 ppm in their tissue. The acute
toxicity level is computed in Table 2 on the basis of a
100 ppm limit on concentration, which would necessitate a
daily increase of .5 ug.
To reach a concentration of 100 ppm in a 5 gm oyster
after 3 years of culture (roughly 1000 days - the average
time needed) the oyster v/ould have to accumulate 500 ug of
copper, requiring an uptake rate of .5 ug/da.y. From figure
7, this would occur with a .2 ppm concentration of copper
in the effluent used for culture.
Schwarze and Alsberg found that the maximum amount of
cadmium in food that could be tolerated without producing
emesis was roughly 400 ppm1t-j. However, reported instances
of poisoning since then have lowered the emetic threshold
concentration to 13 ug/gm cadmium'9>20B This level requires
an uptake rate of .065 ug cadmium/day by the cultured
oysters. A concentration of .080 ppm in the effluent would
be necessary to reach that level after 3 years (1000 days)
culture.
No acute toxicity from ingestion of nickel has been
reported for the levels likely to be encountered in shell-
fish culture. Systemic poisoning from nickel salts is
almost unknown, although dermatitis has occassionally been
noted''. Nickel carbonyl poisoning has been well-documented
but is unlikely to occur in the effluent used for aquacul-
ture purposes.
By oral administration, elevated levels of chromate
(as potassium) cause stunting of growth. Gross and Heller
reported that the maximum amount that can be added to feed
without causing toxic effects was 1/8 of 1 percent, a
concentration of 1250 ppm Cr^'. To reach this level would
require a rate of uptake in excess of 6.2 ug/day, requiring
concentrations in the effluent greater than 10.0 ppm,
unlikely to occur.
97
-------
There is little point in computing limits based on
acute toxicity for lead or zinc, the tv/o remaining metals.
Very little ingested lead or zinc is absorbed in the intes-
tines. Intakes of zinc in the form of chloride or carbonate
equal to 2,500 ppm of the diet shov-r little effect on
animals' '.
Of the six metals, cadmium and lead are known to cause
chronic toxicity from long-term accumulation from ingested
food in humans. ;Ve ^re not avrare, at present, of any
reported cases of poisoning \7hich can be traced to concen-
trations of either of these elements in oyster meat.
However, the critical levels in meat are known or have been
estimated for each of the metals and can be calculated.
t
Kerfoot and Jacobs, using a model similar to tha
employed by Kjellstrom to set cadmium standards in air,
computed that concentrations of cadmium in oyster meat above
3.0 ppm would lead to a critical level in the kidney cortex
if JfO gm of oyster meat were invested daily for 50 years1 3.
This would require a daily rate of uptake of .015 ppra for
the 1000 day culture period. A concentration of .010 pprr.
in the effluent would be necessary to reach this level.
According to Kehoe, any level of lead greater than a
total of .6 mg/day is potentially dangerous22. Using the
generous estimate of 40 gm of oyster meat per day as the
diet, a concentration of 15-0 ppm would be undesirable.
This requires a rate of uptake of .75 ug/day for the 1000
day culture period. A concentration of 6.0 ppm in the
secondary effluent would bring about this eventual level.
Finally, a series of permissible levels were computed
on the basis of alert levels at one time considered -or_,
indicators for pollution for the State of Massachusetts2-?.
The alert levels for Zn, Cu, Cd, Cr, and Pb were, respect-
ively, 2000, 175, 3-5> 2.0, and 2.0 ppm wet meat weight.
Nickel was not specified. The alert levels represent the
upper value three standard deviations from the mean level
found in unpolluted areas. This v/as not meant to indicate
a significance of public health but to serve only as signal
of an unnatural source. Since the standard deviation of
nickel content in oysters is about ±.13» the alert level
based on a .29 ppm natural concentration in the tissue would
be about .70 ppm.
Permissible levels, based on the alert levels, were
calculated in the final row of Table 2. Since zinc was not
accumulated significantly during the study, no limit v/as
calculated for it. As before, the culture period was
assumed to be 1000 days, resulting in a 5 grain oyster.
98
-------
The final permissible level suggested as a. guideline
was taken to be the lowest value occurring in the column
for each metal. Effluent containing a concentration of
metal in solution above or at this level is not recommended
for aquacultural purposes. In three cases, Cr, Pb, and Zn,
the suggested level represented the concentration toxic to
algae. For copper, the level was based on acute toxicity
to humans. With cadmium, it reflected chronic toxicity of
the metal in humans. Oddly, nickel was the only element
whose recommended concentration in the effluent was based
on alert le\rels, representing a level three standard
deviations above that normally found.
Even though the levels of metal in the effluent for use
in the aquaculture system were calculated against standards
suggested for food regulations, many questions are left
unanswered as to whether consumption of the shellfish is
completely safe from a public health point of view, consid-
ering only metals. Total metal content may be misleading
since the structure of the compound is not elucidated.
Organometallic species of metals may be present in effluent
due to industrial discharge or possible reactions encountered
during the sewage treatment process. These compounds, if
present, may have toxic effects not commonly associated with
their inorganic counterparts. Also, the possible carcino-
genic, niutagenic, and teratogenic effects were not consider-
ed here and should be investigated.
The many difficulties which beset the definition and
validity of standards should not delay progressing towards
guidelines, despite their tentative nature. Much will be
gained by establishing the proper limits for metals in
effluents to be used for aquaculture, although the defini-
tion of precise limits to cover all possible toxic effects
may take a long time to develop, particularly since many
oysters sold commercially have been unintentionally exposed
to discharge of municipal effluents, retaining elevated
levels of metals despite depuration for possible pathogenic
organisms.
-------
REFERENCES
1. Kerfoot, W. B. and S. A. Jacobs. Permissible levels of
heavy metals in secondary effluent for use in a combined
sewage treatment -marine aquaculture system I. Monitor-
ing during pilot operation. (Preceding paper)
2. Jacobs, S. A. Some measurements of heavy metal content
of sev/age effluent and sludge. In The Use of Flowing
Biological Systems in Aquaculture, Sewage Treatment,
Pollution Assay, and Food-Chain Studies, J. H. Ryther,
ed., Technical Report V/HOI 73-2, December, 1972.
3, Young, D. R. , C-S. Young and G. E. Hlauka. In Cycling
and Control of Metals; Proceedings of an Environmental
Resources Conference. National Environmental Resaarch
Center, Cincinnati, p. 21, 1973.
4. Ryther, J. H. , W. H. Dunstan, K. R. Tenore and J. E.
Huguenin. Controlled eutrophication - Increasing food
production from the sea by recycling human wastes.
Bioscience 22(3), 144, 1972.
5. Goldman, J. C. , K. R. Tenore, J. H. Ryther and N. Corv/in,
Inorganic nitrogen removal in a combined tertiary
treatment -marine aquaculture system. I. Removal
efficiencies. Water Research, in press.
6. Huguenin, J. E. Experiences with a marine aquaculture-
tertiary sewage treatment complex. (In this volume)
7. Hayward, J. Studies on the growth of Phaeodactylum
tricornutum V. The relationship to iron, manganese, and
zinc. J. Mar. Biol. Assoc. U. K. 49:439-446, 1969.
8. Riley, J. P. and I. Roth. The distribution of trace
elements in some species of phytoplankton grovm in
culture. J. Mar. Biol. Assoc. U. K. 51(1):63-72, 1971.
9. Nuzzi, R. Toxicity of mercury to ohytoplankton.
Nature 237:38-40, 1971 »
10. Hannon, P. J. and C. Patouillet. Effect of mercury on
algal growth rates. Biotechnol. Bioeng. 14:93-101, 1970,
11. Roosenburg, J. Greening and copper accumulation in the
oyster Crassostrea virginica near a thermal electric
generating station. Chesapeake Sci. 10:241-252, 1969.
100
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12. Pringle, 3. H., D. E. Hissong, E. L. Katz and S. T.
Molawk. Trace metal accumulation by estuarine inollusks.
J. Sanit. Eng. Div., Amer. Soc. Civ. Engrs. 94:455-
475, June, 1968.
13. Kerfoot, V/. B. and S. A. Jacobs. Cadmium accrual in a
combined wastewater treatment-aquaculture system. In
Proceedings of the First Annual NSF Trace Contaminants
Conference, W. Fulkerson, R. I. VanHook, W. D. Schults,
eds., Oak Ridge National Laboratories, ORNL-NSF-SATC5,
Oak Ridge, Tenn., March, 1974.
14. Brewer, P. B., D. W. Spencer, and C. L. Smith.
Determination of trace metals in seawater by atomic
absorption spectrophotometry. Atomic Absorption
Spectroscopy, ASTM STP 443:70-77, 1969-
15. Mandelli, E. F. The inhibitory effects of copper on
marine phytoplankton. Contr. Mar. Sci. 14:47-57, 1969.
16. Pringle, B. H. and C. N. Shuster. A Guide to Trace
Metal Levels in Shellfish. Shellfish Sanitation Tech.
Rep., USDHEW, Public Health Service, 19 p., 1967.
17. Browning, E. Toxicity of Industrial Metals, second
ed., Anpleton-Century-Crofts, Butterworth and Co.
(Publishers) Ltd., London, 1969.
1(3. Schwarze, E. \V. and C. L. Alsberg. Pharmacology of
cadmium and zinc. J. Pha.rma.col. Exp. Ther. 21:1, 1923-
19. PHS, Public Health Service Drinking Water Standards,
Revised 1962, Public Health Service Publication 0.
956. U.S. Govt. Printing Office, Washington, D.C.
20. Frank, S. and I. Kleeman. "Food Poisoning". J.A.M.A.
117:86, 194L
21. Gross, V.r. G. and V. G. Heller. Chromates in animal
nutrition. J. Industr. Hyg. 28:52, 1946.
22. Kehoe, R. A. The metabolism of lead in man in health
and disease. Arch. Envir. Health 2:418-422, April,
1961.
23. Issac, R. A. and J. Delaney. Toxic element survey,
Progress report no. 1, Massachusetts Water Resources
Commission, Division of Water Pollution Control,
Publication No. 6108, 25 p., 1972.
707
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CALCULATED YIELD OF SEWAGE LAGOON BIOMASS, A PLAN FOR PRODUCTION, AND
SOME OF THE PROBLEMS INHERENT IN USING BIOMASS OR LAGOON WATER FOR
PRODUCTION OF FOOD AND FIBER
BY
*.** ***
KARL SCHURR and J. M. GOLOMBEK
INTRODUCTION
Lagoon treatment of sewage is rapidly expanding both in the United
States and throughout the world. It is certainly opportune and
appropriate that we should be meeting to exchange information about
our difficulties and successes in the application of research to
sewage lagoon operation and technology. The focus of this paper will
be on the Deshler, Ohio terminal sewage lagoon system. This is an
aerobic lagoon which is 5.4 hectares in area and has an even depth of
0.8 to 0.9 m at the present time. A preceding anaerobic lagoon
receives sewage from the village of Deshler. Two thousand residents
and the town drainage contribute from 1.2 million liters to 2 million
liters of sewage per day. An engineering or construction firm would
evaluate the Deshler lagoon system negatively because it obviously is
designed to accept a much larger volume. Retention of sewage in the
system is from one to several months. The reason for such a capacity
may have been a group of city fathers who were over-optimistic about
the population growth of their village, or architects who were
extremely conservative. Be that as it may, this lagoon is not subject
to the regular ills and misfortunes of lagoon systems whose capacities
are constructed close to the margin of input volumes.
The question of efficiency in lagoon systems needs to be debated no
longer. A lagoon system with sufficient capacity can produce effluent
of the highest quality (there are several studies which document this,
but we will cite Schurr and Schurr and Raum ). In comparative
efficiency, a properly designed lagoon system will convert nutrients
better than standard activated sludge or trickling filter systems.
Lagoons are appropriate treatment methods for small towns, villages,
* Professor of Biology, Professor of Health and Community Services,
Bowling Green State University, Bowling Green, Ohio 43403. Adjunct
Professor, Medical College of Ohio.
** This research was supported in part by grant RDl(Bl) an endowment
from the estate of Margaret Yocum: "Research in Aquatic Pollution"
K. S. Grant, Director. The plan for a "Comprehensive Wastewater
Study" was designed with funding from Bowling Green State University
Dr. Hollis Moore, President.
***President of Inviron Inc., environmental specialists, P. 0. Box
3119 Cleveland, Ohio 44117.
702
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animal feed lots and similar industrial uses. However, they are the
system of choice only where land use and cost of land will permit
their construction. Benefits of lagoons are low construction cost and
low operational costs.
There are two products of lagoon sewage treatment: the water, and a
huge volume of plant and animal material. Both are subjects for our
conference. Plant and animal biomass is quite innocuous from a public
health standpoint. It is not offensive to the senses. If this biomass
is allowed to leave with the effluent, however, it will eventually die
and decay will release the nutrients downstream. We can not tolerate
this eutrophication. Algal blooms in Lake Erie have nearly destroyed
it for swimming and recreational boating because they are so negative
aesthetically. With severe eutrophication, the algae supersaturate
the water with Oo from photosynthesis in the day, but there is zero
oxygen because of respiration at night. Few fish can tolerate such
conditions and even fewer eggs or embryos will survive.
The logical solution to this difficulty would be to remove the biomass
and find a use for it. Many researchers have tried to utilize single
celled algae from primary lagoons, but their efforts have been plagued
with problems. The high yields of algal cultures tantalize physiolo-
gists. Verduin and Schmid3 could document approximately 7000 grams of
protein produced by Chlorella, per m2 of surface, as compared with
about 150 grams for traditional terrestrial crops. The difficulties
in use of primary lagoon algae have been with harvesting where they
clog pumps and filters. This would not be an insurmountable technical
problem, but the population dynamics of the algae vary through the
seasons and many species taste badly or are toxic. Dohms4 has
summarized the efforts to use algae for food. Since outstanding
scientists have found so many problems with unicellular algae, we have
studied the possibility of using multicellular forms, the flowering
plants and invertebrates that grow in the terminal lagoon at Deshler.
A following paper at this meeting by Dr. Bakaitis will evaluate
vitamin content of biomass.
YIELD AND USE OF BIOMASS
Schurr5 and Schurr6 describe potential nutritional value of the
invertebrates, while Dohms and Schurr? document the protein, lipid and
carbohydrate content. Living biomass in the Deshler terminal lagoon
is dominated by Potamogeton foliosus, a flowering plant which has
several growth forms. In the terminal lagoon, the stems break and the
plant blooms in large floating masses which continue to grow through
the summer to a maximum crop in August, September and October. It
forms a thick mat that eventually shades the bottom of the pond.
Water content of the biomass was determined by lyophilization of pre-
weighed samples (Dohms^ & BakaitisS). This rigorous drying of biomass
showed an average percentage of water to be 87% (standard deviation
0.25) for 1971, 1972 and 1973. We took two samples in 1968, three
703
-------
sets in 1969, two sets in 1971 and one sample in 1973. The samples
were blotted in newspaper, and air-dried in sunlight. The final
consistency was the same as well-cured hay. Water content calculated
from this method of drying was slightly above 84%. The method of
drying is much less accurate than lyophilizing, but it more closely
approximates the results from potential commercial treatment. For
this reason, we will use 85% water in estimating productivity. Samples
were raked into a plastic container, excess water was drained, and the
biomass was packed into plastic bags to be frozen for later chemical
analysis or determination of volume. Measurements of the floating
biomass mat gave a calculated yield of wet weight comparable to sample
volume.
A single crop for the terminal Deshler lagoon will yield 1596 cubic
meters of dry biomass per hectare. Proper removal of the floating
material will benefit growth, so that no shading of the undersurface
can occur. We expect this would increase yield to over 2000 m3 per
hectare. Nutritional content of the biomass has been documented over
the growing period by Dohms^. A typical sample for October was
composed of 22% protein, 4% lipid, 40% carbohydrate and 34% ash
(fractions rounded to nearest percent). Oxygen bomb calorimitry
measured energy content per gram of the biomass at 3.86 Kcal to 3.92
Kcal with a standard error of 0.047 on five replicates. Sewage lagoon
biomass, therefore, has considerable potential as a food resource. The
high protein content becomes particularly significant because of the
general shortage of protein. Foss9 has summarized the information,
from the international symposium on "New Sources of Protein Foods,"
as a world requirement for increased protein. This is 3,630,000 metric
tons of new dry weight protein each year for the foreseeable future.
Conventional agriculture and our normal fisheries will not produce this
quantity (SchurrS). Biomass from sewage lagoons may offer another
source of protein.
PROPOSED METHODS OF HARVEST
Methods of handling biomass have yet to be evaluated. The standard
alfalfa drying plant should be able to dry and pellitize biomass. The
consistency of biomass and wet alfalfa cut at night is similar.
Removal from the lagoon is possible with a floating rake pulled to one
end by cable and two electric motors. This would remove floating mats
yet leave attached stems for continued growth. Biomass could be
loaded for transportation with the same pick-up choppers used for wet
alfalfa. These suggested methods of removal would enable harvesting
at the best rate to promote plant growth. They also utilize the
existing technology for alfalfa drying.
ALTERNATIVE USES
The actual disposal of biomass will be determined by the research
which is in progress or has yet to be done. If there are no public
704
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health problems, sewage lagoon biomass could be used as a component in
feed for several domestic animal species. It could even serve as a
fractional part of meat substitutes in the human diet; I have eaten it
and the taste is bland. Feeding of biomass would be particularly
advantageous for animal feed lots, where it could be added to more
conventional feeds. Animal manure could be converted to biomass in
lagoons on the farm and then recycled through the animals again. If
there should be evidence of pathogenic bacteria or viruses in the
biomass, it may be necessary to mix the biomass with corn as ensilage.
As is usual with this feed, the mixing of molasses with the biomass
and corn would certainly increase its nutritional value. Fermentation
and heating would probably destroy pathogens in the silo.
Should some unforeseen problem prevent feeding of biomass, then the
material could be used to generate methanol as is described by Reed
and LernerlO. Mixed-grade methanol can be produced cheaply from
garbage, plant refuse, paper pulp wastes and biomass. Methanol can
be used as a fuel additive to gasoline, where about 15£ will increase
octane, reduce air pollution and extend mileage in standard automobile
engines. Methanol converters could generate fuel, from wastes and
biomass, to be used in municipal vehicles and farm tractors.
A final possible use of biomass would be as a soil conditioner. Such
use would not give as much monetary return as those mentioned above,
but it would dispose of the material. Sweet clover is frequently
planted and then ploughed under in order to improve soil fertility and
texture. Whatever the use, it is necessary to remove biomass from
lagoons so that it will not go out with effluent, die, decompose and
release the nutrients in down-stream areas.
PROBLEMS
The use of biomass or water from lagoons will depend on their freedom
from toxic substances. Pesticides, herbicides and industrial
chemicals must not be present in significant levels. Cyanides are
often released from factories as are lead, mercury, cadmium and
selenium. Unexpected contaminants may be found; Robinson, Draper and
GelmanTI showed that copper sulfate fed to pigs resulted in sufficient
copper in feces to inhibit nitrogen degradation. Radioactive elements
are another possible hazard.
A serious public health concern is the fate of waterborne virus
particles and pathogenic bacteria. Hicks!2, Saslaw"l3 and Kurowski14
show the potential danger. Several studies have been completed on
lagoon systems and the pathogens they may harbor. There has been no
well-controlled study of virus particles in a lagoon system having a
reasonable retention time. We expect several scientific papers which
speak to this problem because there is new commercial equipment now
available for concentrating virus particles from large volumes of
water (Wallis, Homma and MelnicklS). The Deshler system seems to
705
-------
dispose of bacteria rather well (Schurr1). Kott16 has stated that
virus particles are attenuated in the lagoon system that he is testing.
Nevertheless, it is necessary to have exaustive studies completed on
lagoon systems which are properly loaded. It is appropriate that
similar research be done on activated sludqe and trickling filter
systems as a comparison.
Problems May Be Caused By_ Members Of Our Profession
A lagoon system which is "efficient" from the standpoint of land use
and cost, is frequently the type of system that concerns the public
health officer, offends the senses and is an ecological abomination.
We can evaluate lagoons as efficient in cost or loading as opposed to
those which are efficient for their purpose. Our definition of
efficiency is the second type; sewage treatment should convert wastes
to materials or chemicals which can be removed during or after treat-
ment so that the effluent is water of highest quality. Absolute
standards of water quality can be met by trickling filter or activated
sludge systems combined with flocculation and chemical treatment. The
system which is in operation at Lake Tahoe would be an example of
efficiency in our view (Abelson'7). Cost of such a system is quite
high. We differentiate efficiency of treatment from cost in our
discussion because there is a tendency of some designers to mix apples
and oranges, in their calculations, and the product is something that
smells badly. It is wrong ethically and wrong from an engineering
viewpoint to present a plan that mixes circa 60% waste conversion with
construction costs that seem what the traffic will bear. It is also
wrong to view the sewage system as a microcosm and then reject any
responsibility for what leaves it. The public health officer who is
only concerned with heavy chlorination of effluent is in error.
Nothing may be alive in the outflow, but there is an indication that
reactions may take place which produce chlorinated hydrocarbon
residues that will be of public concern in food chains further down
in the watershed. Chlorinated effluent will destroy stream ecology
for miles. There are individuals with tunnel vision. If all bacteria
and viruses are destroyed, they don't concern themselves with the
chlorine, nitrates, nitrites, phosphates, etc. being dumped in our
waterways. Ozone (actually ozonized air) would be a reasonable
alternative to chlorination if the chemical were removed by aeration.
PLAN FOR INTEGRATED LAGOON AND STANDARD SEWAGE SYSTEMS
Many small towns have overloaded sewage plants. They may also have
mixed storm drains and sanitary sewers. This places an intolerable
burden on those responsible for proper treatment of sewage. Bowling
Green State University responded to such conditions by offering land
at no cost for the construction of 400 acres of lagoon system. The
university also financed a comprehensive waste water study (E.C.CJ8).
Bowling Green has mixed storm and sanitary sewers, with a trickling
filter sewage plant that is overloaded during rainfall. The proposed
106
-------
sewage lagoon system would receive all effluent during rainfall and
treatment would progress through a chain of lagoons. Biomass would
be removed from terminal lagoons. Effluent could be pumped back
through the trickling filter system during dry periods. High loadings
could be sent to the lagoons and then brought back to the standard
plant. An efficient removal of phosphates could be achieved most
economically.
The alternatives to this proposed combination of lagoons and trickling
filter sewage treatment plant are as follows. The town must construct
a greatly expanded sewage treatment plant. Design figures on plans
show that even this expanded capacity will be unable to accept the
volume during heavy rains and it will be necessary to bypass. Storm
and sanitary sewers must be separated. We predict that federal regula-
tions will become more stringent and storm water will be treated within
a few years. Better quality standards on effluents will be mandated
by the government. This will require a flocculation system being added
to the new treatment plant.
It is difficult to estimate construction costs within the next few
years because of inflation, energy shortages and land expense. However,
we think the total cost of a new sewage treatment plant, plus separa-
tion of storm and sanitary sewers, plus treatment of storm water, plus
special treatment required as standards increase, may reach the level
of twenty million dollars. No useable product will be produced by
this type of construction. Alternatively, with free land contributed
by the university, a lagoon system could be added to the sewage plant
at a cost of $400,000 to $600,000. A compromise treatment system
composed of a new activated sludge system and a lagoon system would
cost about $7 million and could meet the highest water quality
standards. The town has 20,000 residents listed on the last census,
but this included all students living off campus. Actual residents
are about 15,000. Those with taxable incomes are much fewer. It
becomes obvious that there must be alternatives to standard sewage
treatment because the average American community simply doesn't have
the tax base to build an activated sludge or trickling filter system
that will meet the highest water quality standards. Increased welfare
costs, fire protection, police protection, education, mental health
programs, etc., etc. will all have priority over sewage treatment.
Clean water will be an impossible goal unless we can find ways to
treat sewage at moderate cost.
SUMMARY
We suggest that the proper prescription for optimum sewage treatment
with reasonable costs is as follows. Villages, small towns and
animal feed lots would be appropriate for lagoon systems if land cost
is reasonable. Loading should be moderate so that terminal lagoons
will be aerobic and will produce biomass from plant and animal growth.
The biomass should be removed and commercially used as described in
707
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this paper. Whenever possible, the lagoons should be combined with
standard sewage treatment systems in order to obtain the highest water
quality standards in treatment. The biomass should be recycled close
to the site of production. This may be used as animal feed. We do
not discount the use for humans if it could meet pure food and drug
standards. We may find the proper fate of biomass would be a conver-
sion to methanol to be used as an additive to gasoline. Biomass may
be disposed of as a soil conditioner. Its removal from lagoons,
however, is a necessity if we are to reach the ideal of pure water as
effluent.
REFERENCES
1. Schurr, K. A Comparison of an Efficient Lagoon System With Other
Means of Sewage Disposal in Small Towns. 2nd International
Symposium for Waste Treatment Lagoons. 1:95-100, 1971.
2. Schurr, K., and W. Raum. Comparative Efficiency of Well-Operated
Trickling Filter and Lagoon Sewage Systems. Second National
Symposium on Societal Problems of Water Resources. April, 1973
(Proc. in press)
3. Verduin, J., and W. Schmid. Evaluation of Algal Culture as a
Source of Food Supply. Developments in Industrial Microbiology.
7:205-209, 1966.
4. Dohms, J. A Nutritional Analysis of Sewage Lagoon Biomass.
Master of Arts Thesis, The Graduate School. Bowling Green State
University, 1972, 77 p.
5. Schurr, K. Insects as a Mjaor Protein Source in Sewage Lagoon
Biomass Useable as Animal Food, Proc. N. C. B. Ent. Soc. Amer.
27:135-137, 1972.
6. Schurr, K. Insect Protein in Food Recycled from Sewage Lagoon
Biomass (abstract only; invitational paper). Symposium on
Agricultural Entomology, XIV International Congress of Entomology.
Canberra, Australia p. 303, 1972. (This paper is cited in new
directions for life sciences by Encyclopaedia Britannica Yearbook
for 1973 on p. 422.)
7. Dohms, J. and K. Schurr. Biochemical Evaluation of Sewage Lagoon
Biomass to be Used for Animal Food as Recycled Nutrients. Second
National Symposium on Societal Problems of Water Resources.
April, 1973 (Proc. in press)
8. Bakaitis, N. M. Water Soluble Vitamins in Sewage Lagoon Biomass.
Doctor of Philosophy Thesis, The Graduate School. Bowling Green
State University, 1974, 47 p.
108
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9. Foss, J. G. New Sources of Protein Foods. European Scientific
Notes (ONR) 25:85-87, 1971.
10. Reed, T. B., and R. M. Lerner. Methanol: A Versatile Fuel for
Immediate Use. Science. 182:1299-1304, 1973.
11. Robinson, K., S. R. Draper and A. L. Gelman. Biodegradation of
Pig Waste: Breakdown of Soluble Nitrogen Compounds and the Effect
of Copper. Environmental Pollution. 2:49-57, 1971.
12. Hicks, A. Waterborne Hepatitis-A Outbreak-Alabama. Morbidity
and Mortality. 22:118, 1973.
13. Saslaw, M. S. Typhoid Fever in Florida. Morbidity and Mortality.
22:77-78, 1973.
14. Kurowski, J. Shi gel!a dysenteriae 1 in Colorado. Morbidity and
Mortality. 22:101-102, 1973.
15. Wallis, C., A. Homma and J. L. Melnick. Apparatus for
Concentrating Viruses from Large Volumes. Jour. Amer. Water
Works Assoc. 64:189-196, 1972.
16. Kott, Y. Personal communication. Technion, Haifa, Israel.
6 p. 1971.
17. Abel son, P. H. Long-Term Efforts to Clean the Environment.
Science. 167:1082, 1970.
18. Environment Control Corporation. Comprehensive Wastewater Study
for Bowling Green State University. Painesville, Ohio, 1973,
89 p.
109
-------
PART 3 A QUA CUL JURE
SESSION CHAIRMAN
KENNETH O, ALLEN, Ph.D.
FISHERIES BIOLOGIST
BUREAU OF SPORT FISHERIES AND WILDLIFE
STUTTGART, ARKANSAS
-------
ANALYSIS OF SEWAGE LAGOON BIOMASS WATER
SOLUBLE VITAMINS BY MICROBIOLOGICAL TECHNIQUES
by
Nancy M. Bakaitis*
Eutrophication of surface water resources, due to enrichment from
fertilizer runoff, municipal sewage effluent and other sources, has
led to great economic losses and environmental damage. If the vast
growths of vascular plants and algae, which occur under these con-
ditions, could be harvested economically, mechanical removal would be
an attractive alternative to the chemical treatments now employed.
Water weeds have been suggested as a potential source of nutrition for
livestock by Boydl and Little.2 Recent work on cultivation of aquatic
plants 1n sewage lagoons to remove pollutants and produce a clean ef-
fluent has had considerable success in the United States and in Asia,
according to Oswald and Golueke^ and McGarry and Tongasamer This con-
cept of sewage treatment and food production has also been tested suc-
cessfully by RytherS using aquatic plants in marine systems.
The sewage lagoon system of Deshler, Ohio was studied from 1971 to 1973
to determine the nature of the life forms commonly present and their
nutritional value. The possibilities of sewage treatment and water
purification with the production of a useful product were explored by
several workers including Dohms6, Schurr7"8, and Yerdirtn.
The Deshler sewage lagoon system consists of two ponds with a depth of
approximately one meter. The system handles all of the sewage from a
community of 2000. Pond One receives raw sewage through a submerged
line at the rate of from 300,000 to 500,000 gallons per day, depending
on rainfall. Anaerobic digestion of sewage occurs 1n this nine acre
pond. Pond Two 1s thirteen acres in area and is aerobic. The water
leaves Pond One through two corner outlets and enters Pond Two, which
in turn, discharges Into a small stream. Material from Pond Two was
studied.
*Chemistry Department, Findlay College, Findlay, Ohio.
**This research was supported, 1n part, by funds from grant RDI(BI)
"Research in Aquatic Pollution", an endowment from the estate of
Margaret Yocum.
770
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Pond Two biomass consists of floating plant material in which
Potamogeton foliosus Raf. predominates and has associated with 1t many
aquatic insects at various life cycle stages, aquatic annelids, mites,
and snails. The plant material forms a thick floating mat extending
many feet from the shore toward the center of the pond. Sampling of the
biomass was done by standard random sample techniques with samples being
of 5 to 10 liters in drained volume. Samples were taken at various
intervals during August and September each year when the material was
present in significant quantities. Samples were lypholized and frozen.
Analysis of the water soluble vitamin content of the biomass was con-
ducted to determine if it was comparable to common animal feeds as a
vitamin source. Thiamine, riboflavin, niacin, pantothenic acid, Bi2,
total B6, biotin, choline, and beta-carotene were selected for study
based on the requirements of chickens and swine. Choline was deter-
mined using the method outlined by Sebrell and Harris.'0 Beta-carotene
was found to be present using the procedure of Gyb'rgy and Pearson.'!
All other vitamins were assayed using the preferred microbiological
techniques of the Association of Official Agricultural Chemtstsls the
Association of Vitamin Chemists13, or the United States Pharmocopiae.I*
The content of each of the vitamins studied did not vary significantly
during the growing season or from one year to the next so that the data
was pooled and a mean vitamin content for each vitamin is presented.
Results indicate that the sewage lagoon biomass vitamin content compares
favorably with common feeds, such as, alfalfa, ear corn, dried barley,
sugar beet pulp, and solvent extracted soybean hulls. The amount of
riboflavin present in the biomass is superior to these feeds; and, the
amounts of biotin, choline, niacin, pantothenic acid, and thiamine are
comparable. The total B6 content of the sewage lagoon biomass is low
in comparison to these feeds and would need to be augmented if it was
the sole B6 source in chicken rations. A summary of these findings
is presented in Table I.
Analysis of subsamples of biomass material taken in 1971 were completed
by Dohms6 for protein, carbohydrate, lipid, and mineral content. The
amounts of carbohydrate present was reported as 3.89 Kcal/g dry weight
of material; and, the protein content was found to be 17.9 per cent.
These values also compare quite favorably with dried alfalfa meal, corn,
barley, soybean hulls, and sugar beet pulp protein and carbohydrate
content. The mineral content of the biomass was also found to compare
favorably with these feeds being higher in calcium and zinc, but lower
1n manganese content. A summary of these findings is in Table II.
Therefore, the sewage lagoon biomass from the Deshler, Ohio aerobic
sewage lagoon compares favorably in protein, fat, carbohydrate, mineral,
and vitamin content with commercial feeds. Regardless of the source,
777
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Table I. Vitamin Content of Feeds Compared to Sewage
Lagoon Biomass Mean Vitamin Content for 1971 to 1973a
Vitamin
Biotin
B12
SLB*>
0.36
0.10
Choline 1020
Niacin
Pantothenic
Acid
Total B6
Riboflavin
Thiamine
30.00
13.18
1.35
19.81
5.00
Feed C
::
1550
41.90
20.90
6.50
10.60
3.00
Feedd
0.20
1030
57.40
6.50
2.90
2.00
5.10
Feede
^ ^
829
16.30
1.50
0.70
0.40
Feedf
0.05
Feed9
0.32
550 2743
20.00
5.00
5.00
1.10
—
26.80
14.50
8.00
3.30
6.60
a. Expressed as mg/kg dry weight of material.
b. Sewage Lagoon Biomass mean assayed value based on 1971, 1972
and 1973 samples.
c. Alfalfa, Medicago sativa, aerial portion, dehydrated.
d. Barley, Hordeum vulgare, dried grain.
e. Sugar Beet, Beta saccharifer, dehydrated pulp.
f. Corn, Zea mays, ground ears.
g. Soybean, Glycine max, seed meal , whole, solvent extracted and
ground, 7 per cent fiber. ..
Data for c.-g. from NRC, Nutrient Requirements of Poultry,IS
1971. pp. 24-37. Table 13. Composition of Some Common
Poultry Feeds.
772
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Table II. Mineral Content of Feeds Compared To
Sewage Lagoon Biomass Assayed Mineral Content a
Mineral
Sodium
Phosphorous
Calcium
Potassium
SLBb
0.
1.
3.
1.
Manganese (ppm)464
Magnesium
Iron (ppm)
Zinc (ppm)
Copper (ppm)
0.
1601.
50.
10.
29
03
44
39
.0
41
00
00
00
Feedc
0
0
1
2
29
0
0
20
10
.07
.22
.23
.33
.00
.29
.03a
.00
.40
Feedd
0
0
0
0
16
0
0
15
7
.02
.42
.08
.53
.30
.12
.Ola
.30
.60
Feed6
0.
0.
0.
0.
13.
0.
0.
9.
7.
01
28
04
53
00
15
Ola
00
70
Feedf
0
0
0
2
45
0
0
45
.01
.62
.26
.02
.50
.28
.02*
.00
—
a. Expressed as per cent dry weight unless otherwise indicated.
b. Sewage Lagoon Biomass, Dohms,61972. A Nutrient Analysis of
Sewage Lagoon Biomass. Table VI.
c. Alfalfa, Medicago sativa. aerial portion, dehydrated.
d. Barley, Hordeum vulgare. dried grain.
e. Sugar Beet, Beta saccHarifer, dehydrated pulp.
f. Corn, Zea mays, ground ears.
Data for c.-f. from NRC, Nutrient Requirements of PoultryJ5
1971. pp. 24-37. Table 13. Composition of Some Common
Poultry Feeds.
113
-------
if nutritionally valuable feeds can be found, they will be employed in
animal feeds. The only significant limiting factors are cost and public
health. The cost of sewage lagoon biomass will be determined by the
expense of harvesting and transport, since it is a "waste product" of
sewage treatment at the present time. A positive economic factor is the
present necessity of removing this material from effluents in order to
release clean, treated water. Such removal prevents eutrophication in
down-stream areas of the watershed. Since lagoons are the least expen-
sive method of treating sewage from villages, small towns, and animal
feed lots, the removal of biomass will be the final requirement of la-
goon treatment in the future. With removal of biomass, lagoons also
become the most efficient method of sewage treatment. Removal of bio-
logical oxygen demand, nitrates, nitrites, and phosphates is consider-
ably better than trickling filter or activated sludge systems operating
at optimum efficiency.
Removal and utilization of biomass in feeds would enable our society to
reap a triple benefit. Lagoon treatment could be employed more general-
ly in small communities and for animal feedlots. Secondly, the biomass
could be used for animal feeds near the location of production. Actual
recycling of nutrients would be possible for small geographic areas and
for individual farms. Thirdly, we could approach the ecological ideal
of confining nutrients to the areas where we want to promote growth,
while avoiding dispersal of nutrients to locations where we consider
them harmful to the habitat.
At this time, all studies conducted on the Deshler sewage biomass have
produced results which indicate that biomass would be an excellent feed
supplement. Before a final evaluation of biomass as a feed source can be
made, information must be obtained on the fate of virus particles and
bacteria in a well-operated sewage lagoon system. The combinations of
sewage lagoon biomass with other components of livestock rations and the
effect on growth need to be documented in actual feeding experiments.
It will also be necessary to design methods of harvesting and drying the
biomass.
774
-------
Literature Cited
1 Boyd, Claude E. Freshwater Plants: A Potential Soruce of
Protein. Economic Botany, 22_: 359-368, 1968.
2 Little, E. C. S. (ed.). Handbook of Utilization of Aquatic
Plants, A Compilation of the World's Publications. F. A. 0.,
U. N.f Rome, 1968, 122 p.
3 Oswald, William J. and C. G. Golueke. Harvesting and Processing
of Waste-Grown Microalgae. p. 371-387. In D. F. Jackson (ed.).
Algae, Man and Environment. Syracuse University Press, Syracuse,
New York, 1968.
4 McGarry, M. G. and C. Tongasame. Water Reclamation and Algae
Harvesting. J. Water Pollution Control Fed., 43_: 824-835, 1971.
5 Ryther, J. H. The Status and Potential of Aquaculture, Parti-
cularly Invertebrate and Algae Culture. A. I. B. S. Gov. Print.
Off., PB 177767, Washington, D. C. 1968.
6 Dohms, John. A Nutrient Analysis of Sewage Lagoon Biomass. Un-
published Master's Thesis, Bowling Green State University, Bowling
Green, Ohio, 1972.
7 Schurr, K. M. Insect protein in food recycled from sewage lagoon
biomass. Symposium on Agricultural Entomology, XIV International
Symposium of Entomology, Canberra, p. 303. 1972.
8 Schurr, K. M. Insects as a Major Protein Source in Sewage Lagoon
Biomass Useable as Animal Food. Proceedings North Central Branch
E. S. A., 27_:135-137, 1972.
9 Verduin, Jacob. Phytoplankton energetics in a sewage-treatment
lagoon. Ecology, 52(4);621-631. 1971.
10 Sebrell, W. H., Jr. and R. S. Harris (ed.). The Vitamins. Vol. II
Second Ed., Academic Press, Inc., New York. 1967, pp. 52-55.
11 Gyb'rgy, P. and W. N. Pearson (ed.). The Vitamins. Vol. VI. Second
Ed., Academic Press, Inc., New York. 1967, pp.194-196.
12 Association of Official Agricultural Chemists (ed.). Official
Methods of Analysis of the Association of Official Agricultural
13 Association'of Vitamin Chemists (ed.). Methods of Vitamin Assay.
Second Edition. Wiley-Interscience, New York, 1965, 301 p.
14 U. S. Pharmacopeia. Revision XVI. Mack Publishers, Easton, Pa.,
1960, pp. 42-48.
15 National Research Council, Subcommittee on Poultry. No. 1, Nutrient
Requirements of Poultry. (6th Edition). National Academy of Sciences
Washington, D. C., 1971, 54 p.
775
-------
FEED AND FIBER FROM EFFLUENT - GROWN WATER HYACINTH
by
L.O. Bagnall, T.deS. Furman, J.F. Hentges,Jr.,
W.J. Nolan and R.L. Shirley*
SUMMARY
Water hyacinth was used to remove nutrients, primarily nitrogen and
phosphorous, from secondary treated sewage effluent; some of the plants
were subsequently ensiled or dried and fed to sheep and cattle and some
were pulped to make paper. The irregularly harvested pond removed 10%
of the nitrogen and phosphorous from the effluent, only 10% of which
could be accounted for in the plant tissues. Cattle and sheep readily
ate processed water hyacinth in complete diets and remained in good
health, but did not utilize the nutrients as well as nutrients in a
land forage, coastal Bermudagrass. The primary feeding value is as
sources of energy, mineral elements and roughage for ruminants. Paper
can be made from water hyacinth, but production cost is uneconomically
high. Compost may be the best use, having the highest value and lowest
processing cost.
INTRODUCTION
Fertilization by wastewater often encourages excessive growth of some
plant species in waterways, reducing the availability of the water for
more desirable uses. The focusof this conference is on how to manage
these fertilizing effluents to some beneficial ends. One possible
means to this end is to manage the growth and utilization of one of the
problem species, water hyacinth (Eichhornia crassipes).
Water Hyacinth
Holm, Weidon and Blackburn estimate water hyacinth caused losses of
$43 million in the Southeastern United States in 1956 and that control
•Assistant Professor, Agricultural Engineering; Professor, Environ-
mental Engineering; Professor, Animal Science; Professor, Chemical
Engineering; Professor, Animal Science. University of Florida,
Gainesville, FL.
**The projects on which this paper is based were supported by the Flor-
ida Agricultural Experiment Station, University of Florida Engineer-
ing and Industrial Experiment Station, Florida Department of Natural
Resources, Florida Game and Fresh Water Fish Commission, Southwest
Florida Water Management District, and the Office of Water Resources
Research, USDI, through the Florida Water Resources Research Center.
116
-------
programs cost millions of dollars. Though not the only cause of this
undesirable excessive growth, over-nutrification of the water is a
contributing factor.
Water hyacinth is a large free-floating plant with an attractive laven-
der flower and shiny bright-green leaves on long petioles. Uncrowded
plants, particularly in shallow water and full sunlight, have bulbular
float petioles about 8 inches long, whereas crowded plants produce elon-
gate pwtioles up to 50 inches long . The plants Reproduce from stolons
and, less importantly, seeds. Penfound and.Earle report that the num-
ber of water hyacinth plants doubled every 11.2 to 15.0 days in field
observations and that the edge of a water hyacinth mat extends 2 feet
per month. Bock^reported a 50% weight increase in 13 days, and Knipling
West and Haller observed mass growth rates of 50% in 10-4 days. Stand
densities of 125 to 184 tons per acre have been reported.
4
Water hyacinth grows most rapidly in water temperature from 28 to 30 C
and pH from 4.0 to 8.0 , and ceases to grow when water temperature is
above 40 C or below 10 C. Water hyacinth is killed when the tip of the
rhizome is frozen . The plant has little tolerance for salt water and
will only grow in fresh to faintly brackish water. The plants are
normally free-floating but, if stranded by receding water, will root in
mud and survive. Phosphorous is limiting to growth in concentrations
belowfi0.1 ppm and is consumed in luxury amounts at higher concentra-
tions . Plants usually exhibit lower root-to-shoot ratios as water
nutrification increases.
Because of their habit of vegetative reproduction from stolons, individ-
ual plants remain tied together in a floating mat. In confined waters,
the mat spreads until it covers all the water. Penfound and Earle
report that dissolved oxygen under mats ranged from 0.1 to 1.5 ppm,
depending on mat density, when nearby open water contained 4.0 ppm oxy-
gen. The oxygen depression is caused primarily by decay of detritus
from the mat and in turn causes dramatic changes in the types and
quantities of life in adjacent areas.
Wastewater and Water Hyacinth
Sheffield7 passed extended aeration effluent through a water hyacinth
pond with a detention time of 10 days and observed 81% reduction of
ammonia nitrogen. No reduction in nitrate nitrogen was observed until
anaerobiosis was established at 42 days, after which reduction rose to
81%. Orthophosphates were reduced 51% during the first month of opera-
tion, but reduction fell to 20% after that, as decaying plant detritus
released accumulated phosphorous back to the water.
Clock8 found that a water hyacinth system removed 39 to 94% of the total
nitrogen from extended aeration effluent when the detention time was
five days, with best reduction coming during the period of most vigor-
ous growth. Average nitrate reduction was 61%. Phosphates were re-
duced by 60% during periods of vigorous growth, but increased during
777
-------
dormancy.
Steward9 projected that an acre of water hyacinth can take up the nitro-
gen production of 130 to 595 people from secondary sewage effluent when
growth rate ranges from 294 to 1340 tons per acre-year. At the same
growth the phosphorous production of 40 to 180 people could be absorbed.
Miner, Wooten and Dodd grew water hyacinth on anaerobic swine lagoon
effluent in Iowa and found the system to reduce Kjeldahl nitrogen 95%,
ammonia nitrogen 96%, phosphate 82% and COD 88% in 102 days detention
in pools 18 inches deep, and recommended that depth for application.
Food, Feed, Fiber and Water Hyacinth
Boyd11 found the composition of naturally growing water hyacinth to be
as shown in Table 1. He noted that the composition varies considerably
with location and season, but concluded that, chemically, it was suit-
able for cattle feed. Water hyacinth would be unsuitable for human food
because of its high fiber content. It could be fractionated to yield
leaf protein and other non-fibrous components.
Cattle have been observed eating water hyacinth leaves, especially when
other types of forage were scarce. Hentges reported that cattle ac-
cepted limited amounts of fresh and sun-dried chopped water hyacinth,
but refused some plant parts and stale feed. He fed dehydrated water
hyacinth to cattle at high levels of their diets and found that, though
the animals only maintained their weight, the material was not toxic;
he noted that the quality of the feed was poor due to a combination of
source and processing.
Most paper is made from wood, but other plant materials have been test-
ed as pulp sources. Paper-making from water hyacinth has been suggest-
ed and tried in the past, but thorough, scientific data is not in the
literature.
Processing
The water hyacinth must be removed from the effluent to remove the nut-
rients and put them to use. For most uses the plants must be processed
to reduce bulk and weight, retard or enhance decomposition, and to im-
prove acceptance and utilization. Growth on an artificial pond should
be more consistent in quality and quantity than at natural sites, and
controlled harvesting should be easier, Important factors in commercial
application. The non-conventional harvesters required are available.
The harvested plants' characteristics and some of its proposed uses re-
semble those of some traditional land forages. Forage processing prac-
tices, including chopping, ensiling, drying and pelleting, should be
applicable with modification. Casselman, et. al. explored the use of
presses for reducing the high initial moisture content of some tropical
forages. Pirie1 applied maceration and pressing to extraction of pro-
118
-------
Table 1. Composition of Water Hyacinth'
%, dry basis
(except as noted)
Dry Matter, % wet basis
Crude Protein
Nitrogen
Cellulose
Available Carbohydrate
Ether Extract
Ash
Phosphorous
Calcium
Potassium
Magnesium
Energy, kcal/g dry
5.9
16
2.5
28
7.8
3.5
17
0.42
1.0
4.4
1.1
3.8
a. from Boyd
11
779
-------
tein from freen plants. In both cases, the resulting juice was rich in
protein, minerals and pigments. Pirie describes ways that these valua-
ble components can be recovered, including pH adjustment, aging and
heating which cause coagulation or precipitation. The required tech-
nology for utilization is available and needs only to be adapted to the
crop.
OBJECTIVES
How much nitrogen and phosphates can water hyacinth remove from second-
ary treated sewage effluent? How do pool geometry, season, and deten-
tion time affect removal? How should plant harvest be managed?
What is the cost of producing compost? What is its value? Is there a
market?
Will cattle readily consume processed water hyacinth? Can they utilize
the nutrients the processed water hyacinth contain? Will they perform
well on processed water hyacinth? Are there health-related problems
from eating water hyacinth? What is the cost of producing processed
water hyacinth feed? What is its value? Is there a market?
Can paper be made from water hyacinth? What are the production re-
quirements of such paper? What are the characteristics of the pulp and
paper? What is the value of the paper and the cost of its production?
What product is most feasible, economically?
PROCEDURES
Water hyacinth was grown on extended aeration secondary treated sewage
effluent, harvested, and processed to produce a range of products as
shown in the overall system schematic in Figure 1. Loosely coordinated
individual projects in nutrient removal, paper-making, processing and
animal feeding used the same pool of water hyacinth.
Water hyacinth was established on one of the oxidation ponds at the
University of Florida Campus Sewage Treatment Plant in early April,
1972. Seven bushels of plants were collected from Lake Alice, on the
University of Florida campus about a half mile downstream from the
sewage plant, and placed in the 7400 ft pond, where they initially
covered an estimated 75 ft . Surface coverage was determined period-
ically until the pond was covered. In late May, nine 3x3 ft pens were
built in an adjacent pond and plants were placed in them for mass
growth rate determinations.
Influent and effluent were sampled automatically and analyzed for Kjel-
dahl nitrogen, ammonia nitrogen, nitrate nitrogen, orthophosphate, and
total phosphate. Samples for dissolved oxygen determinations were tak-
en near the center of the pond at 6 inches below the surface, mid-depth
720
-------
CAMPUS
SEWAGE
I
SEWAGE
TREATMENT
PLANT
1
COMPOST
•COMPOST
PULP
•PAPER
OXIDATION
POND
(WATER
HYACINTH)
WATER
HYACINTH
HARVEST -
PROCESS
ENSILE
'SILAGE
1
EFFLUENT
TO
LAKE ALICE
DRY FEED
JUICE
CONCENTRATE
Figure 1. Water Hyacinth Effluent Nutrient Removal -
Utilization Scheme
727
-------
and 6 inches above the bottom.
The pond was operated throughout most of the test with a 15-hour deten-
tion time, much shorter than any reported previously in nutrient uptake
tests with water hyacinth. During the last 2% months of the test, from
early February to mid-April, 1973, detention times of 6 to 24 hours
were used, to establish the effect of detention time in this range.
The system shown in Figure 2, combining conventional and unconventional
forage processes, was used to convert aquatic plants to a variety of
products. It consisted of harvesting, chopping, pressing, ensiling,
drying, pelleting and juice solids recovery operations and produced
compost, pulping stock, silage, dry feed and a feed concentrate.
Plants were harvested irregularly throughout the summer and fall of
1972 by hand or with a small conveyor. Harvested plants were chopped
with a slightly modified forage harvester.
Compost was produced from whole and chopped plants by storing wet
plants aerobically for 1 to 6 months, then drying and grinding. Com-
post was evaluated by mixing with other soil materials and growing
plants in pots.
Large quantities of chopped plants for feed production tests WCKC
pressed in the 12-inch Vincent press used by Casselman, et.al. .
Smaller lots were pressed in the eight-inch and nine-inch presses built
by Bagnall . Methods of recovering nutrients, particularly protein,
from the juice were explored.
Most of the eff 1 u.ent-grown water hyacinth was ensiled. The pressed
water hyacinth was mixed with up to 4% dried citrus pulp or cracked
corn and up to 1% standard cane molasses as free carbohydrate sources
prior to ensiling. Lots of 220 Ib were stored for 21 to 60 days in
polyethylene-lined barrels with trapped drains. Lots of about 3000
pounds were stored in four-feet diameter by 8-feet long asphalt-lined
currugated culverts set on end.
Some of the pressed water hyacinth was dried in a static bed at 125 F
to 140 F and stored as coarsely ground feed. Water hyacinth from other
sources was dried on other types of dryers, including an instrumented
high-temperature rotary dehydrator. Drying characteristics and costs
can be projected from the combined data.
One lot of processed water hyacinth was pelleted through a 3/8x2-inch
die in a flat plate pellet mill. Densities and durabilities were
found and observations made regarding production rate and energy
requirement.
Whole plants, chopped plants, pressed plant residue, pressed juice,
dried plant products, silage and mixed feeds were analyzed for moisture
and nutrients, primarily crude protein and ash. In some cases, more
722
-------
WEEDS
HARVEST
PROCESS
TRANSFER
/\ STORE
USE
WASTE
CONCENTRATE
COMPOST
COMPOST
PULPING STOCK
SILAGE
FEED
PELLET
FEED
Figure 2. Aquatic Weed Harvesting - Processing System
123
-------
detailed analyses, primarily of the ash, were made.
Animal acceptability of water hyacinth products was established by plac-
ing them before the animals for several days, either as the only feed
available or in competition with other feeds, and observing order of
choice and quantity consumed. Feed was weighed before feeding and left-
overs weighed back and replaced each day to minimize effects of deteri-
oration, especially with silage.
Yearling steers were fed dried water hyacinth, dried hydrilla (Hydrilla
verticillata) and coastal Bermudagrass (Cynodon dactyl on) as 33% of the
organic matter in complete pelleted diets to determine acceptability,
as measure by voluntary intake, and utilization of nutrients, as meas-
ured by balance of intake and collected excrement. Sheep and cattle
were fed water hyacinth silage from the culvert and tower silos, alone
and with supplementary dietary components, to determine voluntary intake
and nutrient utilization. Coarsely ground dried water hyacinth press
residue was included as 10% of cattle diets for comparison with cotton-
seed hulls and sugarcane bagasse pellets as roughage sources in a 112-
day feeding trial.
Health of all animals was observed during all trials and selected ani-
mals were slaughtered and examined in detail.
Whole plants and elongate petioles only were chopped and used for pulp-
ing The pulping system is shown in Figure 3. The chopped plants were
passed through an attrition mill to reduce the plants to very small
particles and break the physical bond between fiber bundles and pith.
The pulp was washed on a travelling screen by high pressure water spray,
and the clean fiber bundles were dried and stored. The fiber was pulped
by cooking in experimental digesters using four different processes
shown in Table 2. Pulp fiber strength was developed and fibers separat-
ed by beating. The pulp was tested for freeness, a measure of drainage
rate, and test handsheets were formed. Tear, burst and breaking
strengths were found.
RESULTS AND DISCUSSION
An area growth curve of water hyacinth in the oxidation pond is shown in
Figure 4. Time for doubling of area in the central part of the curve,
following establishment of the stand and before crowding, is 6.2 days.2
This rate of growth is about twice that observed by Penfound and Earle .
When 60% of the water hyacinth was harvested in August, recovery was
very slow until the remaining mat was broken up; peripheral length must
be maximized to assure maximum growth.
Time for 50% increase in wet weight was 7 days, indicating^ growth rate
43% higher than that observed by Knipling, West and Nailer and 86%
faster than that observed by BockJ. Fertilization and other conditions
existing in the pond are conducive to higher than normal growth rates.
724
-------
CHOPPED WATER HYACINTH
ATTRITION
WASTE
WASH
DRY
CHEMICALS
DIGEST
BEAT
FREENESS SAMPLE
FORM SHEET
PAPER
Figure 3. Water Hyacinth Pulping Process
725
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Table 2. Water Hyacinth Paper-Making Processes
Chemical concentration
70 g/1 sodium sulflte
25 g/1 sodium hydroxide
36.6 a/1 sodium bisulfite
Liquor
Ratio
7:1
7:1
12:1
Temperature
C
135 -
121 -
156 -
172
148
162
10-35 g/1 sodium sulfite
12:1 121 - 156
35 g/1 equivalent Na«0, 25$ sulfldlty
sodium hydroxide + sodium sulfide
(kraft process)
726
-------
Q
LJ
OH
LU
§
UJ
or
Q
2
LL
O
100
50
20
10-
2-
POND AREA : 7361 FT
20
40
60
DAYS
Figure 4, Water Hyacinth Area Growth in Sewage Treatment
Plant Effluent Oxidation Pond
727
-------
Dissolved oxygen concentrations in the pond ranged from 0.95 ppm near
the bottom to 3.46 ppm near the surface; anaerobiosis was not an impor-
tant factor in nitrogen reduction. Total reductions of nitrogen and
phosphorous for the year are shown in Table 3 with average influent and
effluent concentrations. Nitrogen and phosphorous removal during the
test are shown in Figure 5. Removal of nurients was much lower than
reported by other investigators, at least partly attributable to much
shorter detention time.
The plant roots extended downward only about 2 inches into the 54-inch
deep pond, exposing the roots to only 4% of the water. The nutrients
must be carried to the roots by turbulence, of which there was little,
and diffusion.lnA shallower pool, such as the 18 inches recommended by
Miner, et. al. would probably be more satisfactory for this applica-
tion. During most of the test period the plants were crowded and not
growing vigorously, so managed harvesting might have improved perform-
ance.
Nitrogen and phosphorous balances for the first ten months of operation
of the pond are given in Table 4. Stand density, based on weight and
area of plants removed for ensiling in August, was 111 tons per acre.
Nitrogen and phosphorous in the plants are based on stand density, area,
known moisture and nitrogen contents and estimated phosphorous content.
Only about 10% of the two nutrients was removed, and only about 10% of
the removed nutrients can be accounted for in the plant tissues. Some
of the missing nutrients may be in the detritus on the bottom of the
pond. With a mass growth rate of 50% every week, 1/3 of the plants
could be removed each week, for a total of 218 tons in the ten months
of testing. This management scheme would have removed 476 pounds of
nitrogen and 127 pounds of phosphorous, instead of the 24 and 6.5
pounds, respectively, shown in the table.
Effect of short detention times on nitrogen and phosphate removal is
shown in Figure 6. Removal is generally greater at greater detention
times but data are very irregular, possibly due to weather and transient
effects, and inconclusive.
Harvesting - Processing
Harvest rates of over 4 tons per hour per foot,of width have been ob-
served for flat-wire-belt conveyors with reels . A conveyor uses less
than 0.33 horsepower-hours per ton. Cost of harvesting was $2.13 per
wet ton; costs at a fixed site with reliable machinery could be as
little as 25% of that figure.
A forage chopping cylinder reduces water hyacinth satisfactorily, but
feed and discharge systems of most choppers must be modified to give a
satisfactory capacity . A 16-inch wide cylinder chops almost 2 tons
per hour per inch of cylinder width and required a minimum of 0.18
horsepower-hours per ton.
725
-------
Table 3. Nutrient Removal for the 12-Month Study Period
Average Average % Removal
Influent Effluent
ppm ppm
Total Nitrogen
Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate Nitrogen
Total Phosphates
Orthophosphates
Table 4. Nutrient Balance in
Entering pond in 10 months
Leaving pond in 10 months
Removal
Removed in Plants, August
Inventory in Plants, February
Missinq
12.11 10.98 9.3
5.57 4.80 13.8
3.88 3.31 14.6
6.54 6.18 5.3
4.19 3.81 8.0
3.18 3.03 4.8
Water Hyacinth - Covered Oxidation Pond
Total Total
Nitrogen Phosphorous
Ib % ID %
6670 2310
6040 2100
630 9.4 210 9.1
24 0.4 6.5 0.3
41 0.7 11 0.5
565 8.4 193 8.2
729
-------
30-
<
O
LU
OC
20-
104
O-
TOTAL NITROGEN
' TOTAL PHOSPHATES
15-HOUR DETENTION
APR ' MAY ' JUN ' JUL ' AUG ' SEP ' OCT ' NOV ' DEC ' JAN
MONTH
Figure 5. Nutrient Removal in Water Hyacinth - Covered
Oxidation Pond
130
-------
2CH
TOTAL NITROGEN
_J
10-
O
2
LJ
o:
o-
TOTAL PHOSPHATES
O
5 10 15 2O
DETENTION TIME , HOURS
25
Figure 6. Effect of Detention Time on Nutrient Removal
in a Water Hyacinth - Covered Oxidation Pond
737
-------
A light-weight, decreasing-volume screw press can readily remove over
75% of the water from ¥iter hyacinth and is reasonably tolerant of un-
even loading and trash . A 12-inch press can easily process 12 tons
per hour and a 16-inch press should be able to process 28 tons per hour.
Estimated energy requirement is 2.5 horsepower-hours per wet ton or 4
horsepower-hours per ton of water expressed.
Relatively sophisticated combinations of chemical, thermal and mechani-
cal juice solids recovery can be used on a fixed site with enough space.
Recoveries of up to 63% were achieved in the laboratory and could be
exceeded with improvement in equipment and technique.
Good quality silage can be made from pressed water hyacinth by adding
about 4% cracked corn or dried citrus pulp and storing anaerobically .
If moisture content of the pressed water hyacinth is below 85%, drain-
age will be negligible. Excellent silage was made in 21 days and 60-
day silage was very acceptable.
Water hyacinth must be dried thoroughly and quickly to make dry feed.
Whole plants in static beds dry slowly and with only 13% efficiency.
Pressed plants dry only 10% faster than whole plants and 60% more ef-
ficiently, but the principal benefit of pressing is the large, rapid
water reduction with low energy input and the small gain in drying per-
formance is a secondary benefit. Without agglomeration of fines, per-
formance would have been much better. A 6000-pound-per-hour rotary de-
hydrator dried 6800 pounds of pressed water hyacinth per hour from 88
to 22% moisture, using 1500 BTU per pound of water evaporated; the high-
er efficiency is partially attributable to fluffing of the product be-
fore and during drying.
Pure dried water hyacinth flows poorly and is very frictional and abra-
sive, causing very low pelleting rates and very high energy requirement.
Mixed feeds containing water hyacinth, corn and soybean meal can be pel-
leted at high rates and reasonable power requirements but pellet den-
sity and durability are lower.
Material balance for the complete processing system producing 100
pounds of dried water hyacinth is shown in Figure 7. Larger or smaller
systems can be scaled proportionally.
Estimated processing costs per dry ton of product are $12.12 for har-
vesting, $1.26 for chopping, $5.25 for pressing, and $26.60 for drying.
Resulting product costs on a bone dry ton basis are $13.38 for compost
at 78% moisture, $33.03 for silage at 80% moisture and $45.23 for dry
feed at 10% moisture. Bases for these costs are a 100-wet-ton-per-hour
interim'ttant operation, 20% solids loss between harvest and product,
$3.00 labor, $0.25 diesel fuel, $0.20 bunker C oil for drying, and typ-
ical machine costs and efficiencies. Neglected were costs of buildings
and transfer and storage equipment. The mechanical operations are cap-
ital-intensive, while drying is energy intensive. Capital and labor
costs per unit of production would be smaller for larger and continuous
132
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2381 chopped hyacinth
2262 water
119 solids
17 protein
20 ash
9,700 BTU
pressed hyacinth
360 water
90 solids
10 protein
10 ash
1931
525,000 BTU
350 water
dried hyacinth
10 water
90 solids
10 protein
10 ash
juice
1902 water
29 solids
7 protein
10 ash
1715
192
1
I
solution
1708 water
7 solids
1 protein
5 ash
water
>
216
288,000 BTU\
24
residue
194 water
22 solids
6 protein
5 ash
dried residue
2 water
22 solids
6 protein
5 ash
Figure 7. Process Material Balance for 100 Pounds of Dried
Water Hyacinth
733
-------
operations.
Composition
Analyses of the chopped and pressed water hyacinth from the oxidation
pond and Lake Alice are given in Table 5. Moisture and protein contents
of the oxidation pond water hyacinth are higher than those of the lake
water hyacinth, in response to fertilization. Ash content is high in
both and should be considered in diet design, both with regard to quan-
tity and balance.
Compost
Composted water hyacinth holds water unusually well. Plants grow poor-
ly in pure compost, but perform satisfactorily in sandrcompost ratios
around 3:1. Estimated market value of the compost is about $46 per ton.
Utilization by Ruminant Animals
Cattle and sheep voluntarily consumed diets containing processed water
hyacinth. When only pressed dried water hyacinth was offered to steers,
consumption was less than 1% of body weight; consumption was Increased
to 1% by adding 30% molasses and to 1.556 by pelleting . Steers con-
sumed 2.1% of their body weight of a pelleted diet containing dried
water hyacinth as 33% of the organic matter; consumption was not gjg-
nlflcantly lower than that of a similar coastal Bermudagrass diet .
Cattle accepted most water hyacinth silages Immediately, but consis-
tently refused silages with no dry carbohydrate additive. The most
acceptable silages had the highest additive (dried2§itrus pulp or corn)
levels, lowest pH, lowest ash, and highest protein . Oxidation pond
water hyacinth silage was accepted better than Lake Alice water hya-
cinth silage.
Digestibility by cattle and sheep of diets containing processed water
hyacinth varied with level of water hyacinth in the diet, source of
water hyacinth and method of processing. Dry matter digestibility in
dried water hyacinth was half that in Bernudagrass hay, apparently re-
flecting nutrient loss 1n the press juice ; however, there were no
differences between the two d1etsdfor net retention and apparent ab-
sorption of ten mineral elements". Digestibility of organic matter
and crude protein was higher in oxidation pond than in lake water hya-
cinth silage, as shown in Table 6, but was highest in pangolagrass
silage .
Animal performance was best when level of water hyacinth, on a dry or-
ganic matter basis, was less than 25% of complete diets for cattle and
sheep. All animals remained in good health throughout all experiments.
Levels of potential toxicants, namely oxalates, nitrates, tanmns,
cyanides and dicouawrin apparently were within safe ranges as no tox-
idty was observed .
734
-------
Table 5. Composition of Processed Water Hyacinth
Oxidation Pond
Chopped Pressed
Dry Matter, % wet basis 4.6 11.7
Crude Protein, % dry basis 14. 8 12.7
Ash, % dry basis 22.5 13.0
Calcium, % dry basis
Phosphorous, % dry basis
Potassium, % dry basis
Sand-s-lica, % dry basis
Crude fiber, % dry basis
Cellulose, % dry basis
Ether Extract, % dry matter
Gross energy, local per gram
Lake
Chopped Pressed
5.0 9.6
11.3 10.6
23.0 17.3
2.28
0.4*
2.0*
5.9*
—
26.1**
Silage***
18.6
9.1
11.2
2.4
0.4
4.7
—
21.7
1.9
4.0
*from Stephens
22
**from Salveson
***from Kiflewahid25
Table 6. Digestibility of Nutrients in Water Hyacinth Silage by Sheep
~Organic MatterCrude Protein
Digestibility % Digestibility %
Oxidation Pond Water Hyacinth
+ DCPb 48 51
Lake Alice Water Hyacinth + DCP 40 53
Pangolagrass + DCP 54 76
afrom Baldwin23
bDried citrus pulp added at ensiling time
735
-------
In feedlot and digestion trials, dried water hyacinths satis-
factorily replaced the conventional roughages, cottonseed hulls and
pelleted sugarcane^bagasse, at levels from 10 to 20% of complete
high energy diets.25
All criteria measured showed processed water hyacinth has a re-
placement value of at least equal to cottonseed hulls and sugarcane
bagasse pellets. Current market price of these products is $40 to
$45 per ton.
Fiber
After attrition and washing, 18 to 20% of the plant material was
recovered as clean fiber.26 In the sulfite process and sulfite-
bisulfite process, pulp yield was as high as 80 to 88% of the fiber
placed in the digester; the highly alkaline hydroxide and kraft pro-
cesses yielded only 40 to 50%. Paper strengths were low when yield
was above 65 to 75%. Cooked fiber bundles had to be beaten to
separate them into individual fibers.
Mechanical characteristics of the papers are shown in Table 7.
Freeness of the water hyacinth pulp is much lower than that of pine
kraft pulp and reduces the freeness of blends. Hyacinth pulp drained
to paper on a screen in 5 to 10 minutes, while pine kraft pulp re-
quires only about 30 seconds; a given plant would have only 6% the
capacity using water hyacinth pulp as it would have with pine kraft
pulp. Slow drainage also produces a paper of non-uniform strength
and texture. Water hyacinth paper had usually high shrinkage and
was dark and dirty-appearing.
Tear factor decreases and breaking length increases with increasing
water hyacinth content in blends and were highest for the alkaline
processes and lowest for the sulfite-bisulfite process. Burst factor
increased with increasing water hyacinth content, was highest for
kraft process and lowest for the sulfite-bisulfite process. Use
of petioles only instead of the whole plants slightly improved
breaking length and tear factor but decreased burst factor and
freeness. Breaking length and burst factor are higher than those
of pine kraft, but low tear factor would make the paper unacceptable
for packaging and low freeness and yield would make it uneconomical
to produce,
CONCLUSIONS AND RECOMMENDATIONS
A water hyacinth covered pond with a detention time of over 10 hours
removed 9% of the nitrogen and 8% of the phosphorous from secondary
treated sewage effluent. Removal is increased to 80% and 60%, re-
spectively by increasing detention time to 5 days. Low plant vigor,
caused by crowding and low temperature, and excessively deep water
reduce removal. Only 10% of the removed nutrients were found in
the plant tissue. Plants should be harvested regularly at the rate
of 25 to 33% per week to maintain maximum growth and nutrient uptake.
136
-------
Table 7. Mechanical Characteristics of Water Hyacinth Pulps and
And Papers at 10-Minute Beating Time
Freeness Tear Breaking Burst
Factor Length Factor
ml m
Pine kraft
65% pine kraft, 35% water hyacinth
50% pine kraft, 50% water hyacinth
Sulfite, whole water hyacinth
Sulfite, water hyacinth peticles
Sulfite-bisulfite, water hyacinth
Hydroxide, water hyacinth
Kraft, water hyacinth
720
160
90
40
20
45
40
30
205
130
95
28
30
15
32
35
4300
9600
10000
7200
7900
6600
8700
>nooo
26
52
54
53
42
40
52
>75
afrom Nolan26
737
-------
Compost can be produced from water hyacinth at a cost of about $3.00
per ton and sold for about $46 per ton. A readily developable mar-
ket to nurserymen and home gardeners is available.
Cattle and sheep readily consumed water hyacinth silage and will con-
sume dried water hyacinth up to 25% of a complete diet. Processed
water hyacinths had nutritional value in cattle and sheep diets
primarily as a source of energy, mineral elements and roughage.
Animal performance and health on diets containing processed water
hyacinths were satisfactory. Estimated production cost of dry feed
is $40.70 per ton and silage is $6.62 per ton. Estimated value as
dry feed is $40 to $45 per ton. Market development depends on con-
sistency of quantity and quality of supply and price.
Paper can be made from water hyacinth, but yield and freeness are
low, making production uneconomical. The paper has good breking
and burst strength but low tear strength. Because of low pro-
duction rate, production cost would be too high to be competetive.
Compost appears to be the most feasible product, followed by cattle
roug hage.
138
-------
REFERENCES
1. Holm, L. G., L. W. Weldon and R. D. Blackburn. Aquatic Weeds.
Science. 166:699-709, 1969.
2. Penfound, W. T. and T. T. Earle. The Biology of the Water
Hyacinth. Ecological Monographs. 18(4):447-472, 1948.
3. Bock, J. H. An Ecological Study of Eichhornia Crassipes with
Special Emphasis on its Reproductive Biology. Berkeley,
University of California, Thesis, 1960.
4. Knipling, E. B., S. H. West and W. T. Haller. Growth Character-
istics, Yield Potential, and Nutritive Content of Water
Hyacinths. Proceedings: Soil and Crop Science Society of
Florida. 30:51-63, 1970.
5. Haller, W. T. and D. L. Sutton. Effect of pH and High Phos-
phorous Concentrations on Growth of Water hyacinth. Hyacinth
Control Journal. Vh59-61, 1973.
6. Haller, W. T., E. B. Knipling and S. H. West. Phosphorous
Uptake and Distribution in Water Hyacinth. Proceedings:
Soil and Crop Science Society of Florida. 30:64-68, 1970.
7. Sheffield, C. W. Water Hyacinth for Nutrient Removal. Hyacinth
Control Journal. 6:27-30, 1967.
8. Clock, R.M. Nitrogen and Phosphorous Removal from a Seconday
Sewage Treatment Effluent. Gainesville, University of Florida,
Doctorial Dissertation, 1968.
9. Steward, K. K. Nutrient Removal Potentials of Various Aquatic
Plants. Hyacinth Control Journal 8_: 34-35, 1970.
10. Miner, R. J., J. W. Wooten and J. D. Dodd. Water Hyacinths to
Further Treat Anaerobic Lagoon Effluent. In: Livestock Waste
Management and Pollution Abatement. St. Joseph, Michigan,
American Society of Agricultural Engineers, 1971, 170-173.
11 Boyd, C. £. The Nutritive Value of Three Species of Water Weeds.
Economic Botany. 23(2):123-127, 1969.
12 Hentges, J. F. Processed Aquatic Plants for Animal Nutrition.
Proceedings: Aquatic Plant Research Conference. Gainesville,
Governors Aquatic Research and Development Committee, 1970,
62-67.
139
-------
13. Casselman, T. W., V. E. Green, Jr., R. J. Allen, Jr., and F. H.
Thomas. Mechanical Dewatering of Forage Crops. Gainesville,
University of Florida, 1965. AES Technical Bulletin 694.
14. Pirie, N. W. Leaf Protein: Its Agronomy, Preparation, Quality
and Use. Oxford, Blackwell Scientific Publications, 1971.
15. Bagnall, L. 0. A Simple Screw Press for Water Hyacinth. Procee-
dings: Association of Southern Agricultural Workers. 70_:28,
1973.
16. Phillipy, C. L. and J. M. Perryman. Mechanical Harvesting of
Water Hyacinth (Eichhernia crassipes) in Gant Lake Canal,
Sumter County, Florida.Tallahassee, Florida Game and Fresh
Water Fish Commission, 1972.
17. Stewart, J. S., III. Energy and Flow Requirements for Chopping
Water Hyacinths. Gainesville, University of Florida, ME
Thesis, 1972.
18. Bagnall, L. 0., R. L. Shirley and J. F. Hentges. Processing,
Chemical Composition and Nutritive Value of Aquatic Weeds.
Gainesville, University of Florida Water Resources Center, 1973.
19. Bagnall, L. 0. Mechanical REcovery of Water Hyacinth Press Liquor
Solids. St. Joseph, Michigan, American Society of Agricultural
Engineers, 1973, Paper 73-562.
20 Bagnall, L. 0., J. A. Baldwin and J. F. Hentges. Processing and
Storage of Water Hyacinth Silage. Hyacinth Control Journal.
12:{in press), 1974.
21 Byron, H. T., Jr. Nutrient Value of Water Hyacinth Silage for
Cattle and Sheep. Gainesville, University of Florida, MSA
Thesis, 1973.
22 Salveson, R. E. Utilization of Aquatic Plants in Steer Diets:
Voluntary Intake and Digestibility. Gainesville, University
of Florida, MSA Thesis, 1971.
23. Baldwin, J. A. Utilization of Ensiled Water Hyacinths in
Ruminant Diets. Gainesville, University of Florida, MSA
Thesis, 1973.
24. Stepehens, E. L. Digestibility Trials on Ten Elements and Three
Toxicants in Aquatic Plant Diets Fed Steers. Gainesville,
University of Florida, MSA Thesis, 1972.
-------
25. Kiflewahid, B. Composition and Digestibility of Processed Water
Hyacinths. Gainesville, University of Florida, Doctoral
Dissertation, 1974.
26. Nolan, W. J. and D. W. Kirmse. The Papermaking Properties
of Water Hyacinths. Hyacinth Control Journal. 12:(in press),
1974.
747
-------
THE AVAILABILITY OF DAPHNIA FOR WATER QUALITY IMPROVEMENT
AND AS AN ANIMAL FOOD SOURCE
By Ray Dinges*
INTRODUCTION
Modern aerobic biological wastewater treatment facilities are
capable of reducing biochemical oxygen demand of their influ-
ents by some 85 to 90 per cent. The biological activity occur-
ring in such plants has been described by Dinges^- as the fermen-
tation phase of biological treatment and is characterized by ex-
ternal digestion facilitated primarily by solubilization of
organic material by bacterial enzymes. See Figure 1. Secondary
to the fermentation phase is the consumption phase which is
characterized by internal digestion. The predaceous consumption
phase essentially occurs in receiving waters. It should be
understood that the three phases outlined signify dominant fea-
tures and are not separate and apart but overlap to different
degrees dependent upon water quality and physical conditions of
the environment. Insects, for example, may be present in all
three phases.
This paper deals with what has been termed the consumption
phase, and specifically, a Daphnia dominated community. In
recent years there has been considerable interest developed
regarding the possibilities of expanding conventional processes
of biological wastewater treatment for reduction of remaining
organic fractions by utilizing higher life forms. Uhlmann24
Loedloff3, Erlich^, Scheithauer and BickS, and DeWitt and
Candland^ have all investigated the potential of utilizing
Daphnia to attain improvement of wastewater effluent.
Kryutchkova? discussed energy flows in wastewater stabilization
ponds as related to consumption of particulates by zooplankton.
Greer and ZiebellS utilized asiatic clams Corbicula for reducing
the content of phosphorus from stabilization pond effluent
through their consumption and deposition of algae and other
suspended matter. Development of a wastewater treatment pro-
cess making marine filtering organisms available to consume
particulates from treated effluent is continuing at the Woods
Hole Oceanographic Institution in Massachusetts.
DESCRIPTION OF DAPHNIA
As reported by Ward and Whipple^, Daphnia habitats include tem-
porary pools, small ponds and lakes. Daphnia are common aquatic
* Division of Wastewater Technology and Surveillance, Texas
State Department of Health, 1100 West 49th Street, Austin,
Texas, 78756.
-------
Figure 1
BIOLOGICAL
ORGANIC STABILIZATION
NON VIABLE
ORGANIC WASTE
FERMENTATION PHASE
BACTERIA
FUNGI
PROTOZOA
ALGAE
ETC.
External digestion
Ciliotes
Stalked Ciliates
Rotifers
Etc.
SOLUBLE ORGANICS
COLLOIDS
BIOMASS
DETRITUS
CONSUMPTION PHASE
OAPHNIA
CILIATES
STALKED CILIATES
ROTIFERS
ETC.
Internal digestion
Bacteria
Fungi
Protozoa
Algae
Etc.
SOLUBLE ORGANICS
COLLOIDS
BIOMASS
DETRITUS
PREDACEOUS CONSUMPTION
FISH, INSECTS, ETC.
743
-------
crustaceans about 1/8 inch in length and feed upon algae, bac-
teria, protozoa and debris. Food particles of a proper size
are apparently filtered from water and consumed in a rather
indiscriminate manner.
Daphnia exhibit both sexual and parthenogenic reproduction. A
population will consist almost entirely of parthenogenic females
when environmental conditions are satisfactory. A parthenogenic
female may produce 30-40 new Daphnia every two days. Male
Daphnia appear when environmental conditions become less than
optimal and sexual eggs are produced. Two eggs are enclosed in
a dense, durable structure called the ephippium. Sexual egg
production serves to assure survival of Daphnia when habitat
conditions again become favorable. The life span of Daphnia is
about one month. Two species found in Texas wastewater stabili-
zation ponds were Daphnia pulex and Daphnia similis. Daphnia
similis is shown in Figure 2.
ENVIRONMENTAL FACTORS
Stabilization ponds supporting Daphnia populations were noted to
have effluents that were macroscopically clear and stable. With
cooperation of field staffs of the Department and the Texas
Water Quality Board, as well as municipal employees and the
chemists of our Central Laboratories, a concerted effort was
made during 1970 to 1973 to identify ponds supporting Daphnia
populations. Occurrence of Daphnia was found to be quite uncom-
mon, as they were present in only 29 pond systems out of the
470 domestic wastewater treatment facilities in Texas utilizing
ponds. Field surveys were conducted to evaluate environmental
factors affecting Daphnia with the intent of establishing, if
possible, a continuous culture for effluent improvement.
See Figure 3.
LIGHT
Observations made during the first year of the field studies
revealed quite clearly that Daphnia population pulses in stabi-
lization ponds were seasonal phenomenon. Daphnia populations
appeared during the early winter months and disappeared in late
spring. Figure 4 represents available sunshine and air tempera-
ture data on a monthly average basis as indicated by weather
records for Austin, Texas. It was postulated that a Daphnia
population pulse was either dictated by temperature, or photo-
period.
After having made a review of the literature and conducting
further studies, it was concluded that, in Texas, photoperiod
is the dominant environmental factor affecting Daphnia in
stabilization ponds. The consequence of long periods of bright
1HH
-------
Figure 2
Daphnia slmllls
-------
Figure 3
DAPH NlA PONDS
A — pulex
— si mi I is
746
-------
Figure
AVAILABLE SUNSHINE
JAS ONDJ FM AMJJ
747
-------
sunlight is an excessive production of phytoplanktonic algae
in ponds which results in high pH caused by algal uptake of
available free carbon dioxide and the subsequent shift in the
carbonate equilibrium at the expense of bicarbonates. Ammonia
is almost always present in Texas stabilization ponds. As
early as 1934, ChipmanlO, demonstrated toxicity of ammonia to
Daphnia at elevated pH levels.
TEMPERATURE
Ammonia toxicity results from dissociation of ammonia, which
is a function of both pH and temperature, with ammonia becoming
more toxic with an increase in temperature. Stahl and Mayll,
and others have shown that microstratification occurs in shallow
stabilization ponds as a result of high temperature and lack of
wind induced mixing. Stagnant lower layers in a stratified
pond often are anaerobic and provide suitable environments for
sulphate reducing bacteria. Warm water temperature enhances
growth rate of the bacteria and sulphides produced are quite
toxic. Scheithauer and BickS have stated that Daphnia can tol-
erate up to 3.0 ppm of hydrogen sulphide, but prefer a level
less than 0.4 ppm.
Several observers have attributed demise of Daphnia populations
to water temperature increase. Algae free Daphnia cultures
were maintained in shallow, outdoor concrete containers exposed
to full sunlight during the past three summers. Water tempera-
tures recorded daily in mid-afternoon during the summer of 1970
in an exposed culture container 14 inches in depth were typi-
cally in the upper 80Ts F°. Monthly mean, maximum and minimum
surface water temperatures of Texas ponds during the period
from 1967 to 1973 are depicted in Figure 5. It appears logical
to assume that endemic strains of pulex and similis are able to
withstand normal water temperatures in Texas stabilization ponds.
DEPTH
The physical characteristic most common to ponds with Daphnia
populations was that of water depth. The usual depth of Texas
stabilization ponds is 3 feet. Almost all ponds supporting
Daphnia populations had depths varying from 5 to 15 feet. It is
believed that lower layers of a deep pond have reduced pH^levels
suitable as an environment for Daphnia provided that sufficient
dissolved oxygen for respiratory needs is present. Abnormal
pond depth usually resulted from:
1. Deep ponds provided to serve as irrigation water
holding basins.
2. Terrain considerations - Pond systems constructed
on slopes or in uneven areas that made it uneconomic
to level bottom.
148
-------
I
.
Figure 5
TEXAS POND TEMPERATURES
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3. Air-Aqua - Standard depth of 10 feet.
Several pond systems with Daphnia populations reported in the
literature also were more than 3 feet in depth. Shallow Daphnia
ponds mentioned were mixed by recirculation, or aeration.
MINERAL
Taub and Dollar^ t ±n devising a compatible media for concurrent
culture of Daphnia pulex and Chlorella. reported that certain
ionic relationships resulted in Daphnia mortality. They conclu-
ded that chloride should be the dominant anion and that a sodium
to potassium ratio of less than 10:1 could result in toxic
conditions. In addition, nitrate toxicity was variable, but
decreased with an increase in chloride. They further concluded
that chloride content should always exceed that of nitrate and
nitrate level be kept as low as consistent to algae growth.
Mineral content and ionic relationships in Daphnia pond waters,
therefore, assumed importance, as a serious handicap would
exist in using these animals for effluent clarification if
certain types of waters should preclude their production. Water
samples were collected for mineral analyses from all ponds sup-
porting Daphnia. On an average basis, the dominant anion found
in Daphnia pulex pond waters was bicarbonate, but at times
chloride was dominant. In waters of Daphnia similis ponds,
chloride was usually the dominant anion, but on occasions
bicarbonate was dominant. The lowest sodium-potassium ratio
found in Daphnia pulex pond waters was 6.5:1, with a low of
4.7:1 in Daphnia similis pond waters. In most instances, there
was a great difference between chloride and nitrate levels,
with the chloride ion being dominant. However, on two occasions,
nitrate levels in excess of chloride levels were found in waters
of a pond supporting Daphnia pulex. The highest nitrate level
found in Daphnia pulex pond water was 82 ppm and 55 ppm in
Daphnia similis pond water. Results of field investigations
indicate that mineral composition of waters in Texas wastewater
stabilization ponds is suitable for Daphnia production. Mineral
content of pond waters was found to determine dominance between
Daphnia pulex and Daphnia similis. with pulex being restricted
to relative soft, iron bearing waters of East Texas, whereas
similis existed in hard, mineralized waters found in West Texas.
Table 1 presents observed mean and extreme mineral levels in
pulex and similis ponds. An overlap in range occurs on any
individual mineral parameter between similis and pulex pond
waters, but means and maximums exhibit significant disparity.
750
-------
Table 1
Mineral Levels in 19 Daphnia similis Ponds N=70
ppm
Calcium
Magnesium
Sodium
Potassium
Bicarbonate
Sulphate
Chloride
Dissolved Solids
Hardness
Total Alkalinity
Minimum
13
3
59
3
133
28
53
437
80
170
Maximum
186
70
630
33
620
580
790
2,490
660
510
Mean
61
23
291
15
329
218
276
1,254
249
276
Mineral Levels in 10 Daphnia pulex Ponds N=21
ppm
Minimum Maximum
Mean
18
5
111
7
183
48
80
496
76
155
Calcium 6 56
Magnesium 2 11
Sodium 55 225
Potassium* 2 12
Bicarbonate 31 400
Sulphate 16 85
Chloride 40 160
Dissolved Solids 308 800
Hardness 27 172
Total Alkalinity 25 328
* N=16
BIOLOGICAL
Fish probably would represent the most significant predator on
Daphnia. as Daphnia are recognized as excellent fish food or-
ganisms. In Texas, Dingesl3 found that five fish species are
potential inhabitants of wastewater stabilization ponds, or in
otherwise dry stream courses receiving flow of stabilization
pond effluent.
1. Mosquito Fish - Gambusia spp.
2. Warmouth - Chaenobryttus coronarius
3. Golden Shiner Minnow - Notemigonus crvsoleucas
4. Southern Black Bullhead - Ictaluras melas
5. Carp - Cyprinus carpio
Of the fishes listed above, only mosquito fish were ever noted
to occur in ponds supporting Daphnia populations, and then only
757
-------
in small numbers. Few ponds in Texas are known to support fish
populations other than Gambusia, although almost all systems
have been reported to have had fish introduced into the ponds.
Several insects would be potential Daphnia predators. Of these,
probably diving beetles Dytiscidae would be most important.
Both the larvae and adults of this insect are very efficient
predators in the aquatic environment. Diving beetles could
possibly retard initial development of a Daphnia population,
especially if they were present in large numbers, but Daphnia
productive capacity is so great that a population would soon
expand beyond the point where predation would make much of an
impression.
Daphnia are not alone in clarification of water. The rotifers
Brachionus and the stalked ciliates Vorticella were often noted
as bionts on Daphnia and both feed upon suspended organic mat-
ter. Among other metazoa recorded were Ostracoda, Amphipoda,
Mollusca, Acari, Insecta, Moina and other varieties of Branchi-
poda all contributing to the stabilization of organic material.
DAPHNIA CULTURE
Waters in a Daphnia culture unit are maintained in a clear,
clean condition. Uhlmann^ termed this condition as a
klarewasserstadium, or clear water stage. In a klarewasser-
stadium, the population is in a state of semi-starvation with
males being present and sex eggs evident. Daphnia populations
tend to become balanced with available food supply and popula-
tion growth rate is restricted by presence of sexual animals
and a reduction in parthenogenic birth rates. A klarewasser-
stadium would be maintained if the objective of culture is
production of high quality effluent. The population would be
fed at a rate in excess of their dietary requirements in order
to maintain continual parthenogenic reproduction at an advanced
level if biomass production for commercial purposes is intended.
CULTURE UNIT
A small pond was constructed by the City of Giddings, Texas, to
serve as a Daphnia culture unit at their Northside wastewater
treatment plant, which consists of an Imhoff Tank and three
stabilization ponds in series. A portion of effluent from the
final pond was diverted to the culture unit. The outlet from
the pond was provided with a concrete, broad crested, rectangu-
lar weir eight feet in length and with a crest width of six
inches to reduce outflow velocity and washout of Daphnia.
(Dingesl1* has prepared a paper on biological considerations
of stabilization pond design for enhancement of zooplankton
production, which is too lengthy to discuss here).
752
-------
The first study phase was an investigation of the effectiveness
of pH control by the regulation of pond exposure to sunlight and
the resulting reduction of algae growth. The second phase eval-
uated both pH control by chemical addition and sulphide reduc-
tion through the mixing of pond waters by diffused air.
EFFLUENT QUALITY
Effluent quality results of samples collected weekly during the
first run are presented in Table 2 and results of samples col-
lected weekly during the second run are presented in Table 3.
Table 2
Mean Effluent Quality of Daphnia Culture Unit
1-6-72 to 3-23-72
Detention - 11 days N=10 Loading - 35 Ibs. BOD5/acre/day
Influent Effluent % Reduction
, ppm
COD, ppm
VSS, ppm
Total coliforms
Fecal coliforms
45.4
271.1
77.2
32,860.
6,880.
14.2
90.6
10.8
9,160.
84.
68.7
66.6
86.0
72.1
98.7
Table 3
Controlled Operational Period of Daphnia Culture Unit
2-27-73 to 4-9-73
Detention Time - 11 days Loading - 43.6 Ibs. BOD5/acre/day
Date
February 27
March 6
8
13
16
19
21
27
3
9
Mean
April
Influent, ppm
BOD5
90
80
105
25
30
30
40
40
85
50
57.5
COD
245
310
320
75
115
45
110
110
160
95
158.5
VSS
179
121
142
27
29
33
56
58
63
76
78.4
Effluent, ppm
BOD5 COD VSS
11.8
60
60
90
60
65
90
25
70
95
85.
70
8
11
8
8
9
3
5
41*
19
18.
13
Percent Reductions - BOD& - 79, COD - 55, VSS - 83
* Rotifer bloom in plant pond and passed through unit.
753
-------
The BOD^ remaining in the effluent from a Daphnia culture unit
could be expected to approach the level of soluble BOD5 of the
influent. Soluble nutrient minerals were not removed in passage
through the culture unit. Phosphate levels remained about the
same and nitrates and organic bound iron increased.
See Figure 6 and Figure 7.
LOADING
Maximum permissible hydraulic and organic loading and minimum
detention time on the culture unit were not determined. It is
believed that a unit with a 5-day detention time would be sat-
isfactory and that a 10-day detention time would be conserva-
tive, but could serve as a working basis for unit design until
the process is further evaluated.
Organic particulates entering a unit are mostly consumed in the
immediate vicinity of inflow where masses of Daphnia congregate.
Organic loading, measured by the BOD5 test, would not actually
be relative as the test is based primarily upon respiratory
requirements of fermentative organisms. The significant por-
tion of the oxygen demand in a culture unit would probably be
exerted by the Daphnia dominated zooplankton community.
Daphnia survive quite well when only a trace of dissolved
oxygen exists. Mixing of nominally clean waters of unit for
soluble sulphide suppression would take precedence over aera-
tion per se, although mixing of contents entails aeration.
Mixing-aeration should be minimal to needs as Daphnia are weak
swimmers unable to resist even slight currents. The single
point, fixed feature of mixing-aeration utilized in the Giddings
culture unit was excessive, and dissolved oxygen levels fluc-
tuated around 5 ppm.
PRODUCTION - HARVEST - MARKETING
DeWitt and Candland^ relate that commercial Daphnia harvest in
California stabilization ponds commenced in 1968. The amount
harvested was HO tons, with one pond yielding 25 tons at a rate
of 1.5 tons per acre per month. Bogatova and Askerovl^, mass
culturing Daphnia in concrete tanks on media including yeast
and fertilizer, achieved a sustained yield of 76.7 Ibs. per
acre foot per day. One Texas pond system, consisting of four
35 acre ponds 5 ft. in depth, produces Daphnia 4-5 months each
year. Even at a somewhat lower production rate than those
above, the harvestable tonnage of Daphnia would be considera-
ble. Daphnia in California were harvested by hand nets and a
pump equipped with screening device. A man with a dip net was
said to be able to harvest up to 100 Ibs. per hour when standing
crop was high. A 100 gpm pump was used to pump pond water
754
-------
Figure 6
NITRATE ACCUMULATION IN
CULTURE UNIT
1973
Influent
Effluent
MAR.
APR.
MAY
755
-------
Figure 7
{RON ACCUMULATION IN
CULTURE UNIT
1972
0.40r-
0.30 -
0.20 -
0.10-
JAN.
FEB.
MAR
756
-------
onto a screen on one occasion and rate of Daphnia harvest
attained was 2 Ibs. (wet-drained) per minute.
Various types of manufactured screening equipment suitable for
Daphnia harvest are available as well as low speed separators.
Screen mesh sizes of 40-60 would serve to remove most Daphnia
from water. A proposed approach to Daphnia harvest would be to
pump culture unit water through removal device with discharge
back to unit. Baby Daphnia and food material would return to
unit and aid in sustaining production. A movable, lightweight,
perforated boom supported by floats could serve as a collector
for pump input. Daphnia tend to swarm and form dense localized
concentrations. The boom could be moved to such areas as re-
quired.
There is little need to expound about an ever increasing need
for protein as animal food additives. Wastewater produced
Daphnia may represent a significant unexploited potential source
of animal protein for this purpose.
Analysis of a sample of Daphnia pulex collected from the
Giddings culture unit indicated a content of 65.3 per cent
protein on a dry weight basis. The potential market for
Daphnia is probably considerable. The existing market is quite
limited. DeWitt and Candland6 stated that the 40 ton harvest
of 1968 in California was sold to wholesalers to be used as
aquarium fish food. They report that frozen Daphnia brought
15 to 25 cents per pound when sold to wholesalers, depending
on market need and size of order. They further pointed out
that the aquarium fish food market would soon be flooded should
Daphnia production become commonplace.
It is believed that one excellent use for Daphnia would be as
protein supplement in fish food pellets used by hatcheries and
commercial fish farmers. Ghadially16 has pointed out that
Daphnia are first class fish food, but that an exclusive diet
of Daphnia provides excessive roughage causing a laxative effect
resulting in poor growth. Production of bait fish, such as
golden shiner minnows, in a nearby separate pond and fed on
harvested Daphnia could prove to be feasible. Daphnia could
also be employed as protein additives in pet and livestock
foods.
DISCUSSION
Several thousand stabilization ponds are currently in use in the
United States. Some would favor outright abandonment of ponds
for wastewater treatment considering that their ultimate effi-
ciency has been attained and found wanting due to excessive pro-
duction of volatile suspended solids which are largely composed
757
-------
of algae cells. Others feel that this economic, dependable
process can be further improved through objective research with
close cooperation between engineers and biologists. Figure 8
reveals relationship of light-temperature to volatile solids
levels in Texas stabilization ponds as determined from results
of analysis of 2,02M- effluent samples collected from 1967-1973.
Minimum average indicated production is about 40 ppm, with
volatile solids level in summer being around 80 ppm. May-
September anomalies denoted by arrows could reflect seasonal
algae species change. The May anomaly had been noted pre-
viously by Dingesl'.
An organism that may have potential value for improving waste-
water treatment plant effluent either alone, or in conjunction
with Daphnia culture is the introduced asiatic fresh water clam
Corbicula. These small clams have a very high reproductive
potential and are able to clarify water rapidly. They have
been spreading throughout the United States since the 1930fs
and Dinges^-8 has reported that they now infest three Texas river
basins. During this study, clams were placed in wire baskets
and suspended near the outfall of the Giddings stabilization
pond. The animals promptly died. There is a need to define
their basic environmental requirements. It may well be that
like Daphnia. they are sensitive to ammonia and soluble sulphide
toxicity.
CONCLUSIONS
1. Incorporation of advanced biological methods into wastewater
treatment systems to make use of fertile effluents for cultiva-
tion of beneficial organisms appears feasible.
2. Daphnia culture in wastewater effluent requires pH control
within a range of 7.0-7.5 and sufficient mixing for suppression
of soluble sulphides.
3. Equipment exists for harvest of Daphnia. but the market is
now limited to aquarium fish food. It is believed that a poten-
tial market for Daphnia as a protein source for animal foods
exists.
4. Advanced biological wastewater treatment offers the possi-
bility of salable products to offset treatment costs, or perhaps
to turn a profit. The resulting clarified effluent is condi-
tioned for biological, or chemical-physical methods for further
nutrient removal and is still available for irrigation or indus-
trial use.
755
-------
Figure 8
TEMPERATURE — LIGHT V.S.S.
IN TEXAS STABILIZATION PONDS
1967 - 1973
700
600
-
.- 5 00
c
3
*»400
«
r
35
Q.
M
1
1
5
VolotJie
- Available
Suspended! Solid
Sunshlnt
Temperature
N » 2024
1 i
90
•
u
TO
60
50
o
£
a.
_
.
SONDJFMAM
MONTH OF THE YEAR
759
-------
ACKNOWLEDGEMENT S
The support of Henry L. Dabney, Division Director, and assis-
tance from my fellow employees and many other people involved
in the studies reported upon are appreciated.
REFERENCES
1. Dinges, R. Ecology of Daphnia in Stabilization Ponds.
Austin, Texas State Department of Health, 1973, 155p.
2. Uhlmann, D. Influence of Dilution, Sinking and Grazing
Rate on Phytoplankton Populations of Hyperfertilized
Ponds and Micro-ecosystems. International Association
of Theoretical and Applied Limnology. 19:100-124.
November 1971.
3. Loedloff, C. J. The Function of Cladocera in Oxidation
Ponds. Proceedings of the Second International Water
Pollution Research Conference, Tokyo. p. 307-325, 1964.
4. Erlich, S. Two Experiments in the Biological Clarification
of Stabilization Pond Effluents. Hydrobiologia.
27_:70-80, 1966.
5. Scheithauer, E., and H. Bick. Okologisch Untersuchungen
an Daphnia magna und Daphnia pulex im Freiland und im
Laboratorium. Scientific Papers from Institute of
Chemical Technology, Prague. 8_:439-481, January 1964.
6. DeWitt, J. W., and W. Candland. The Water Flea. The
American Fish Farmer, p. 8-10, January 1971.
7. Kryutchkova, N. M. The Role of Zooplankton on the
Self-Purification in Water Bodies. Hydrobiologia
31_:585-595, 1968.
8. Greer, D. E., and C. D. Ziebell. Biological Removal of
Phosphates From Water. Journal of the Water Pollution
Control Federation. 44_:2342-2348, December 1972.
9. Ward, H. B., and G. C. Whipple. Freshwater Biology.
New York, John Wiley and Sons, Inc., 1959, 1248p.
10. Chipman, W. A., Jr. The Role of pH in Determining
the Toxicity of Ammonium Compounds (Doctoral Thesis)
University of Missouri. 1934, 155p.
11. Stahl, J. B., and D. S. May. Microstratification in
Wastetreatment Ponds. Journal of the Water Pollution
Control Federation. jJ9_:72-88, January 1967.
12. Taub, F. B., and A. M. Dollar. A Chlorella-Daphnia
Food-Chain Study: The Design of a Compatible
Chemically Defined Medium. Limnology and Oceanography.
9_:61-74, 1964.
13. Dinges, R. The Ennis Study - Experimental Chlorination
of Stabilization Pond Effluent. Austin, Texas State
Department of Health, 1970, 117p.
160
-------
1M-. Binges, R. Biological Considerations in Stabilization
Pond Design. Paper Presented to 56th Texas Water
Utilities Short School, Texas A & M University,
College Station. (Unpublished) March 1974.
15. Bogatova, I. B., and M. K. Askerov. Experience in Large
Scale Breeding of Water Flea Daphnia magna. Rybn Khoz.
12_:21-26, 1958 (Biological Abstract No. 227M-2, 1965).
16. Ghadially, F. N. Advanced Aquarist Guide. London,
The Pet Library Ltd. 1969, 282p.
17. Dinges, R. Cyclical Chemical Changes in a Eutrophic
Reservoir. Report - Austin, Texas State Department
of Health. (Unpublished) 1970, 19p.
18. Dinges, R. Asiatics Invade Texas. Water-Southwest
Water Works Journal, p. 7-8, June 1973.
161
-------
REPORT ON PILOT AQJJACULTURE SYSTEM USING DOMESTIC
WASTEWATERS FOR REARING PACIFIC SALMON SMOLTS
George H. Allen and Larry Dennis—
BACKGROUND TO PROJECT
The utilization of animal wastes, and particularly human wastes,
to fertilize waters for improving the growth of aquatic organisms has
an ancient past (Allen'' 2; Mortimer and Hickling*). Most reclaimed
wastewaters used for food and fiber production in the United States is
for increased plant growth on land (Law^; Wilson and Beckett5). "Waste
treatment lagoons" have grown rapidly in treating a wide variety of
wastes, especially treatment of domestic wastes by smaller communities
(McKinney, Dornbush and Vennes6). Such lagoons are now attracting at-
tention because of their potential for management as highly fertilized
fish ponds (Ryther, Dunstan, Tenore and Huguenin7). Catfish (Muggins
and Backman°; Hallock and Zeibell^), bait fish (Trimberger'0) and sal-
mon ids (Anon. ) have been reared in these lagoons in the United States.
In California about one percent of the state's water demand is sup-
plied by re-use of wastewaters (Deaner'*). About 85% of the use
California is for agriculture, thus wastewater re-use for production
food and fiber in California is primarily in agriculture (Deaner1-*).
Of the 1^0 reclamation sites listed for 1971, about 100 included some
type of lagoon in the system, but no uses involving fish rearing were
listed. Reclaimed water was reported in use in four recreational lakes
and in four other lakes for miscellaneous purposes. Studies of these
systems have been primarily on their reliability of operation in order
to protect public health (Jopling, Deaner and Ongerth"'*). The poten-
tial uses of algae grown in wastewater ponds,in California has had a
long history of investigation in California.
In 1955, the City of Arcata constructed a 55-acre oxidation pond
on the intertidal flats of the north arm of Humboldt Bay (Figure 1).
This was the first stage in protecting commercial oyster beds, and other
aquatic resources, from human fecal contamination. Fisheries personnel
early became interested in the potential of this oxidation pond for aqua-
culture, and three studies were directed, either entirely or in part,
toward this aim (DeWitt^; Hansen'6; Hazel'7). Subsequently the City
has installed a primary treatment plant, a facultative aeration pond,
and a chlorination unit at the oxidation pond outlet (Allen, Conver-
sano and
ion of
M Fisheries, School of Natural Resources
~ Humboldt State University, Arcata, California, 95521.
752
-------
Initial formal proposals for aquaculture studies in the Arcata
system were made in 1963, with financial support available from the
Humboldt County Board of Supervisors. A pond system was approved for
funding as a demonstration project by the U.S. Public Health Service
but never received sufficiently high priority for appropriations. Pre-
liminary studies of the pond water through 2-week standing water bio-
assay using chinook salmon fry indicated that the undiluted water of
the oxidation pond under oxygen saturation was non-toxic during winter
months (Allen and O'Brien'9). When the ratio of sewage to diluting
water from infiltration in to the sewer collecting system increased
with cessation of winter rains, the oxidation pond effluent became tox-
ic to fingerling salmon by June. These studies indicated the feasibil-
ity of a pilot project, which was subsequently funded by the California
Department of Fish and Game, Wildlife Conservation Board. Two ponds,
each about 1/3 acre (0.15 hectare) in surface area, were placed into
operation in July 197K Fryer^0 recently reported the need to demon-
strate in pilot projects preliminary results on vibriosis control, de-
veloped in laboratory experiments.
Modern methods for the culture of salmon and trout (Qncorhynchus
and Sal mo) employ highly mechanized operations (Leitr \tz2TJ~. This has
resulted because of historically high labor costs in comparison to
energy costs. Mechanization has included automatic feeding machines
using pellets made in part from high-quality animal protein, particu-
larly marine fish. The cost of both plant and animal protein used in
fish foods, along with the cost of energy to run machines, has been
sharply rising within the last few years. Thus any simple aquaculture
system for rearing trout or salmon utilizing natural food chains de-
veloped by low-cost fertilization, or by feeding low-cost raw materials,
will have immediate practical application in salmonid culture.
GENERAL OBJECTIVES OF PROJECT
The initial objective of our pilot project was to test by empiri-
cal means the capacity of brackish and saltwater fertilized with treat-
ed domestic wastewaters to produce food for juvenile salmon. Our in-
vestigations have the ultimate practical objective to ascertain if this
cultural technique can rear young salmon to migratory size (smolts) as
effectively and economically as salmon cultural methods now employed.
Once data have been gathered to meet our primary objectives, the
system lends itself to experiments with a wide range of local species
of fish and shellfish, both singly, or in various selected combinations
(polyculture).
OBJECTIVES OF THIS REPORT
This paper reports the results of six salmon rearing experiments
completed from July 1971 through December 1973. Four experiments in-
volved short-term rearing of fingerling coho salmon (0. kisutch)
763
-------
conducted during summer through late-fall periods. Two experiments in-
volved J>-k month rearing of chinook salmon fry (0. tshawytscha) during
winter-spring growing periods. As previously mentioned, for both coho
and chinook salmon experiments, the objective was to produce smolts.
Smolts are juvenile salmon that lose characteristic lateral marks (parr
marks) as freshwater feeding fish, become silvery in color, and physio-
logically become adjusted for salt-water osmoregulation. Results of
these experiments are reported in terms of survival and growth. Factors
causing mortalities are discussed, along with evaluation of the results
and future plans.
ACKNOWLEDGEMENTS
Funds for the capital cost were provided by the Wildlife Conserva-
tion Board, California Department of Fish. Operating funds have been
provided through the California State gniversity Coherent Area Sea Grant
Program. The continued interest and encouragement of both the adminis-
trative and elected officials of the City of Arcata have been a great
source of satisfaction as it involves considerable cooperation and good-
will by all parties involved. Mr. Al Merritt, in charge of the recir-
culating fish hatchery at the University campus, reared most experiment-
al salmon used in the system. He also conducted bioassay in our hatch-
ery of culture waters used in pond experiments. Many undergraduate and
graduate students have conducted studies in the system and provided much
voluntary help. Many faculty have directed student projects involving
aspects of the pond system. To these many people we wish to extend ac-
knowledgement of their aid, and express our sincerest appreciation.
DESCRIPTION AND OPERATION OF SYSTEM
PHYSICAL FEATURES
Fish ponds are located on the west side of the oxidation pond to
allow access to a small creek channel located between the oxidation
pond and a landfill dump (Figure 1). Saltwater taken from this ditch
is introduced into the ponds through a 3'-diameter tar-coated pipe fit-
ted on the pond-side with an Armco cast-iron valve (Headgate, Figure 2).
Wastewater is introduced into North Pond by a 1'-diameter pipe located
in the northeast corner of North Pond which connects with the oxidation
pond. There is no pipe connecting the oxidation pond with South Pond,
but fertilization can be accomplished by use of a Barnes trash pump ca-
pable of pumping at about 350 gallons per minute. A fish-collecting
basin located immediately in front of each headgate is the deepest part
of each pond (about 2.0 meters). Each basin also contains a small sump
allowing complete dewatering of each pond by use of the trash pump.
Headgates are fitted with stainless-steel screens of 1/8-inch diameter
circular openings.
Three different types of material were used in construction of the
ponds. A yellow sandy loam (Hookton Series) was used for pond banks.
764
-------
HUMBOLDT
BAY ARE.A
ARCATA
(NORTH)
BAY
SOUTH
HUMBOLDT
BAY
ARCATA
STUDY
AREA
SANITARY LAND FILL
•ARCATA WASTE WATER
TREATMENT PLANT
POTENTIAL AREAS
FOR MAR| CULTURE.
OXIDATION POND
JACOBY
CREEK*
higure 1. Location of study areas mentioned in text,
765
-------
SLOPE
HINS6
POJNT
"-32'
(APPRO*.)
ure 2. Physical features of 'orth (top) and South (bottom) fish ponds.
766
-------
River-run gravel was cast around each headgate to allow light machinery
access to the area for excavating of fish-collecting basins. A third
material, oyster shell, was specifically employed to provide artificial
substrate for production of food organisms. This material was placed
in several low spots in the pond bottoms and along portions of the pond
banks. A fourth material (mud) was the original intertidal sediment
plus overlying organic matter deposited during operation of the oxida-
tion pond. Mud covered a majority of the pond bottoms. Pens two-meters
square of nylon bobinetting were constructed in each pond over a sample
of each of the four substrates. These pens (Exclusion Pens, Figure 2)
were originally used to exclude fish from these substrates, but now
serve to rear known numbers of fish over each bottom type. The ponds
have been operated as static systems to conform to directions from the
North Coast California Regional Water Quality Control Board (no waters
containing unchlorinated effluents may be discharged into Humboldt Bay
without at least two weeks retention time). In practice, we have rarely
discharged unchlorinated wastewater that has not had about a month re-
tention in the system. Ponds could be operated as a tidal-flushing sys-
tem but due to the expense and complexity of having to chlorinate these
flows, we have not as yet operated with tidally-flushed ponds receiving
a continuous addition of wastewaters.
B10ASSAYS
In order to assist in identifying periods of mortality, or to iden-
tify causes of mortality, lots of salmon taken from those planted into
the ponds were reared in aquaria in the hatchery (Hatchery Bioassay) or
in floating pens in the fish ponds (Live-car Bioassay).
HATCHERY BIOASSAY
Standing-water bioassays were conducted in 20-gallon aquaria kept
at hatchery water temperatures by placing the aquaria in hatchery
troughs. The aquaria were serviced with compressed air introduced
through air stones to maintain oxygen saturation in the water. There
was no feeding of lots of salmon being tested in these bioassay experi-
ments.
Hatchery bioassay was undertaken to measure mortalities due to
toxicity of water used in salmon culture. Various combinations of
oxidation pond water, saltwater from Humboldt Bay or from the open
ocean at Trinidad Head, as well as the mixtures of oxidation pond wa-
ters and Humboldt Bay water employed in North and South ponds, were
tested. Although not designed for the purpose of measuring improve-
ment of water quality from operation of the system, data from such
hatchery bioassay can be used to estimate how well Arcata plant efflu-
ent meets recently adopted state standards on toxicity (Calif. State
Water Resources Control Board22), Only a small part of hatchery bio-
assay data are reported here.
LIVE-CAR BIOASSAY
767
-------
Floating pens (live-cars) were employed to obtain daily counts of
mortality of salmon. Two types of cages were employed (Table 1). One
type (cage) was made from 2" x *+" wooden frames fitted with nylon bobf-
netting. A large cage 4' x V x 2' employed mesh of hexagonal openings
7 mm in longest and 3 mm in shortest diameter. A small cage 21 x 2' x 2'
employed circular mesh of 1 mm diameter. A second type of live-car used
was called an "insert" because of its mode of construction. A 2' square
wooden frame was fitted with plastic floats and a hinged lid. An inside
lip was made to hold a frame which was used to support a collapsible
hanging net of mesh 7 mro by 3 rom hexagonal openings. The lower port-ion
of the net was kept vertical and square by sewing into the lower peri-
meter a stainless steel square frame.
Accurate daily mortality counts using cages were not available.
Due to the size and weight of the cages it was difficult for a single
man to entirely remove the cage from the pond. Dead salmon could remain
undetected on the bottom of the cage where a carcass could be completely
consumed by amphipods in less than 12 hours when high numbers of amphi-
pods were present in the ponds. The insert live-car could be easily re-
moved from the pond by one man, thus greatly increasing reliability of
daily mortality measures with this type of live-car.
AERATION AND MIXING
Upwe11i ng
Initially we used a low-cost system producing "upwelled" water (Fig-
ure 3). Water was taken from the surface by a small electrically-driven
water pump and discharged through a simple manifold at the bottom of each
fish-catching basin. The intake jet was kept on the surface by a styro-
foam plastic float. The systems created an "upwelling" immediately ad-
jacent to each headgate. Whenever aquatic higher plants occurred in the
system, constant plugging of intake and impellers in the pumps developed.
The pumps were not marine models and deteriorated rapidly in the waste-
water-saltwater solution.
A spray system was the second method of aeration employed (AIR-0-
LATOR, Roycraft Industries). The instruemnt drives surface water into
the air by use of a small impeller rotating at very high speeds (Figure
k). As originally mounted by the manufacturer, the instrument did not
provide protection for salmon against the impeller blades. We mounted
the instrument on a styrofoam block, fitted into the end of a 55-gallon
oil drum. The lower end of the drum was covered with nylon-mesh to ex-
clude fish. The water enters the drum near the bottom of the pond,
moves vertically, to be sprayed into the air. These units have been
located near the fish collecting basins. AIR-0-LATOR parts used by us
were primarily fashioned for freshwater operations, thus galvanic ac-
tions due to saltwater caused complete disintegration of some parts of
768
-------
Table 1. Description of "live-cars" used in monitoring water
quality of pond waters for juvenile salmon and for daily
measure of mortality
Live-Car Descr ipt ion
Frame Mesh
Large Cage 4' x V x 2' Nylon bobinetting; hexagonal mesh;
7 mm long and 3 mm shortest dia-
meter.
Small Cage 2' x 2' x 2' Nylon bobinetting; circular mesh;
1 mm in diameter.
Insert 21 x 2' with As in large live-car; mesh on re-
plastic floats movable frame hung 3' deep with
stainless steel frame at bottom
to maintain shape.
Fry 11" x I1*" x 20" Wire mesh of 1/8" square openings.
765
-------
Figure 3. Upwelling mixing and aeration unit, South Pond
headgate. Pen (SC) over gravel shown right
corner; crab pen middle background.
Figure k. AIR-0-LATOR spray system, South Pond, with
Pen (SC) over gravel. Fish barn in back-
ground to house recirculating system for
holding and marking salmon.
170
-------
the unit. The electric motor unit (Franklin), however, appears quite
rugged and watertight, and has performed adequately. Plastic parts
have now become available and are to be tested in the system.
Air
North Pond was fitted with a forced-air aeration system during the
summer of 1973 (Figure 5). Air lines with associated jets are located
immediately off the portion of the North Pond bank not associated with
an oyster shell covering. A vertical 2-foot wall exists in this portion
of the pond, and the air jets breaking the water surface plus the verti-
cal bank serve to discourage predation by fish-eating birds (herons,
egrets, night herons). A second pipe leads directly to the fish catch-
ing basin to a U-shaped manifold insuring complete mixing of all pond
waters.
POND WATER PROPERTIES
Daily observations of water temperature, turbidity, hydrogen ion
concentration, dissolved oxygen, and salinity were made from surface
samples obtained at the headgate of each pond during morning hours (8-
10 AM). Additional water properties were studied only intermittently.
Considerable day-to-day fluctuations in some of the properties oc-
curred (pH, turbidity, oxygen) (Allen23). |t was possible to fit curves
to the raw data by eye showing major trends during each experiment
(Figures 6-9). Time of each experiment is listed in Table 2.
Water temperature was primarily controlled by air temperature.
Local weather conditions (storms in winter, cloud or fog cover in sum-
mer) cause yearly variations. During summer months, the ponds ranged
near 20 C (Figure 6). Such temperatures are found in estuaries and la-
goons in northern California and Oregon at this time of the year (jo-
seph2**, Hayes 5, Reimers2"). Ice covered our ponds once during the two
winters of operation to date and then only for a day. Diurnal changes
in temperature, as determined from cursory analysis of thermograph
charts obtained from an instrument operated about a foot under the wa-
ter surface, are relatively small (2-3 degrees at most).
Turbidity, primarily a function of phytoplankton populations,
showed high variability during coho rearing periods (fall and early win-
ter) (Experiments I, III, IV, VI) (Figure 7). High turbidity from phy-
toplankton occurred during both chinook rearing periods (winter-spring)
(Experiments II, V).
Hydrogen ion, primarily a function of photosynthesis, was always
quite high, generally between values of 8 to 9.5, with a few cases of
values near 10 (Figure 8). No similarity in trends could be discerned
during winter periods (Experiments I, III, IV, VI) although the average
value was about pH-8. In contrast, the winter-spring conditions pro-
duced pH's tending toward values in late spring of 9-9-5.
777
-------
• I
' .
<
Figure 5. North Pond during pond modification, summer 1973t showing
retaining wall and air line at base.
-------
o
LU
or
Of.
Id
a
I
UJ
15-
10
j
M J J A
MONTH
N
Figure 6. Trends in pond water temperatures, North Pond, salmon rearing
-------
UJ
o
a.
a.
U.
o
Q.
Ld
no
IOO
90
80
70
50
40
30
20
10
LL
I
JFMAMJJASONDJ
MONTH
Figure 7. Trends in water clarity, North Pond, salmon rearing experiments
I-VI.
-------
10
a
X
d.
M
M J J A
MONTH
N
D
Figure 8. Trends in hydrogen ion concentrations, North Pond, salmon rearing
experiments I-VI.
-------
Dissolved oxygen was always high, and only on a few occasions fell
below 5 mg/1 (Figure 9). In those instances, salmon mortalities could
be correlated with these low values, especially during periods when wa-
ter temperatures were high. No pattern was discerned in oxygen trends
during the fall-winter experiments (Experiment I, Ml, IV), except for
Experiment VI which under Air aeration maintained a constantly high oxy-
gen level. Winter-spring patterns were somewhat similar with high ini-
tial levels followed by a slowly dropping trend, and a sharp drop at the
latter portions of the experiment (Experiment I I and V). These low
points are associated with periods of intense overcast from local heavy
fogs that have followed a period of bright sunshine.
Salinities have been the most stable property, with any sharp chan-
ges occurring toward lower salinity values as associated with periods
of heavy rainfall. Adjustments in pond salinities were made to experi-
mental values by small discharges of pond water to the bay and addition
of higher-salinity water in return. During spring periods, salinities
have slowly tended to increase, probably due to evaporation. Salinity
ranges have not been graphed but are listed with tabular data as needed.
DESCRIPTION OF EXPERIMENTS AND SALMON SURVIVAL
Salmon rearing has been grouped into six periods (experiments)(Ta-
ble 2). Eleven lots of salmon were planted as part of these experiments.
To date, coho salmon have been planted only as fingerlings (juvenile
salmon 6-9 months old). Coho rearing has been conducted during the sum-
mer (Experiment IA; Experiment III), or during late fall, (Experiment
IVA; Experiment IB, IVB, and VI). Chinook salmon experiments employed
fry (young salmon that have absorbed their yolk-sac and have been active-
ly feeding from two-four weeks). Chinook rearing has taken place only
in winter (Experiment II and V).
Salmon utilized in our experiments were obtained from the Califor-
nia Department of Fish and Game hatcheries located on Mad River, Hum-
boldt County, California, and on the upper Klamath River (Iron Gate
fish hatchery). Salmon planted into the ponds were mainly reared at
the Humboldt State University recirculating fish hatchery although some
were reared at the Mad River hatchery or a Humboldt County hatchery lo-
cated on Prairie Creek.
EXPERIMENT IA
Water was initially introduced into North Pond on July 21, 1971
and it was allowed to mix until July 23 when initial plants of coho sal-
mon were attempted. From July 23-28, 5,000 fingerling coho salmon were
introduced into each pond. Water quality in North Pond was poor and
salmon with darkened coloration and listless behavior were observed on
the surface after about three days residence. In South Pond, coho plant-
ed had been acclimatized for U8 hours at 15 o/oo salinity at 16-17°C
temperature, but this was unsuccessful as acute mortalities occurred al-
most immediately in salinities of 32-32.5 o/oo (parts per thousand).
776
-------
15--
HI
x
O
a
uJ
~
O
t/1
01
5
10
n
A M
J J A
nONTH
N
Figure 9. Trends in oxygen concentration, N'orth Fond, salmon rearing
experiments I-VI.
-------
Table 2. Summary of rearing experiments in North Pond with juvenile Pacific salmon using Humboldt
Bay seawater mixed with wastewater from City of Arcata oxidation pond.
Expert- Rearing
ment No. Period
IA Jul -
IB 7 Dec
II 1 1 Feb
17 Apr
III 7 Aug
IVA Oct 72
IVB 3 Nov
V 26 Jan
16 Mar
26 Apr
VI 2 Nov
Oct 71
71 - 22 Jan 72
- 2 Jun 72
- 2 Jun 72
- 22 Sept 72
- 17 Nov 72
- 26 May 72
- 26 May 73
- 26 May 73
- 15/16 Dec 73
Species
Coho
Coho
Chinook
Ch inook
Coho
Coho
Coho
Ch inook
Chinook
Chinook
Coho
Size of
Fish
Fingerl ing
Fingerl ing
Fry
Fry
Fingerl ing
Fingerl ing
Fingerl ing
Fry
Fry
Fry
Fingerl ing
Days of
Rearing
-
45
111
45
45
-
14
119
70
52
43
Aeration and Mixing
System
Upwe 1 1 i ng
Upwel 1 ing
Upwel 1 ing and Spray
Upwel 1 ing and Spray
Spray
Spray
Spray
Spray
Spray
Spray
Ai r—
Sal inity
(parts per
thousand)
19-24
13-16
11-12
11-12
16-23
13-16
15-17
10-1 3"^
10-13-L7
10- 13!'
10-18
]/ South Pond; 18-20 and spray aeration.
2/ South Pond; Spray.
-------
The number of salmon recovered from around the edges of the ponds was
about seven times as great from South Pond as was recovered from North
Pond. North pond fish tended to sink to the bottom, while South Pond
fish skittered on the surface and tended to float. Feeding salmon were
observed on South Pond surface but rarely on North pond. Some coho sal-
mon survived in South Pond until early September. Additional small num-
bers of coho salmon were introduced into North Pond during August but
these all succumbed as indicated by total mortalities recorded in live-
car bioassay. Bioassay in live-car continued to show high mortalities
through late September.
During July-September 1971, salinities in North Pond ranged be-
tween 19-24 o/oo. Water temperatures ranged around 20°C. Oxygen lev-
els showed typical wide diurnal variations associated with highly eu-
troplc conditions. Salmon mortalities in live-car bioassay were corre-
lated with dissolved oxygen level of from 2-3 mg/1 .
EXPERIMENT IB
Beginning in mid-October, 1971, coho salmon planted into live-cars
in North Pond showed about 70 percent survival over a two-week period.
During November, survival increased to about 80 percent of the salmon
retained in live-cars over a month's time. Based on these results,
17,000 coho salmon averaging 10.5 grams per fish, were introduced into
North Pond, between October 18 and 7 December 1973 (15,000 were planted
7 December 1973). On January 22, 1972, 9.500 salmon were recovered and
released into Humboldt Bay. The average weight of the surviving salmon
was 15.0 grams. Survival was 55 percent over the 45-day rearing period
for the bulk of this fish planted (7 December 1973).
EXPERIMENT I I
North Pond remained empty from 22 January until February 9, 1972,
when effluent and saltwater were mixed into the pond. Some additional
water was added on February 10 and 11. Salinities on 11 February varied
from 11 o/oo at the surface to 15.5 o/oo at 3-foot depth. The pond was
initially aerated by upwelling, then by spray. The AIR-0-LATOR unit
failed during the experiment and was replaced by the upwelling pump re-
fitted for aerial spray. In late April the AIR-0-LATOR was replaced
with a new unit, and the pump refitted for upwelling. On 2 June the
pond was drained.
Between February 11-14, 1972, 10,000 chinook fry were planted into
North Pond, followed by 2,500 fry marked by excision of the left ventral
fin (LV). On 2 June, 2.5 percent and 4.0 percent of these two groups
of salmon were recovered as smolts.
EXPERIMENT I I I
On June 28, 1972 a mixture of saltwater and oxidation pond water
was introduced into North Pond to form a salinity of 16 o/oo. Live-car
779
-------
bioassay showed high mortalities of coho salmon through July but with
slowly improving survival rates throughout the month. During live-car
rearing periods temperatures fluctuated around 20° + 2°c. From July
28 to August 11, three introductions of finger ling cbho of about 1,000
fish each were made into water of about 18 o/oo salinity. On 22 Sep-
tember the pond was drained and 3.9 percent of the 3,000 salmon recover-
ed. In addition over 50,000 fingerling topsmelt and sticklebacks were
recovered. These latter fish had developed entirely from eggs and lar-
vae in the saltwater introduced from Humboldt Bay at the initial filling
of the ponds.
EXPERIMENT IVA
North Pond was filled with seawater and effluent in late Septem-
ber, 1972 and adjusted to produce a salinity of 15 o/oo. Live-car bi-
oassay was begun on ^ October, with no mortality over a 10-day period.
In order to repeat Experiment I with a longer period of rearing, 16,000
coho fingerlings were placed into the pond on October 13. A group of
50 salmon was placed into the live-car. On October 13, 19 salmon died
in the live-car (38 percent), which correlated with a period of low oxy-
gen level (£3 mg/1). On November 3, only 12 percent of the live-car
fish remained. High numbers of distressed fish were being eaten by
birds (Blankinship*7). We assumed that most fish in this experiment
had died.
EXPERIMENT IVB
As part of the objective of Experiment IVA was to allow a study of
bird predation, we had retained 5,000 fingerlings in our hatchery as
reserve, and these were placed into the pond on November 3. On 17 No-
vember the pond was drained and 4,220 fingerlings were recovered (84
percent survival over 14 days of rearing). No mortalities occurred in
live-car bioassay during the rearing period.
EXPERIMENT V
Both North and South Ponds were filled with seawater during Decem-
ber 1972 but had to be emptied in early January 1973 for some pond re-
pair and maintenance work. Oxidation pond effluent was introduced in
mid-January to obtain two levels of salinity (about 9 o/oo for North
pond and 18 o/oo in South Pond). Two stocks of chinook salmon were
made available for this experiment. One stock was from early-run sal-
mon returning to Mad River hatchery, and the second stock later-running
salmon to Iron Gate fish hatchery on the Klamath River. A group of late-
run salmon was retained in the Humboldt State University hatchery for
planting in late April in order to allow the salmon to become large
enough to be marked by fin excision (left ventral fin - LV). South Pond
was drained on 25 May and North Pond on 26 May 1973. Surv.val of fish
over the three rearing periods ranged from 0.1 to 6 percent (Table 3).
750
-------
Table 3. Survival of chinook salmon fry planted into North and South Ponds, Experiment V,
North Pond
Stock
Mark
Date Salmon Planted
Number Planted
Days Reared
Percent Survival
Early Run
None
26 Jan
1 ,800
119
6
Late Run
None LV
16 Mar 26 Apr
7,500 2,500
70 30
1 1
South Pond
Early Run
None
26 Jan
1,800
no
2
Late
None
16 Mar
7,500
70
0.1
Run
LV
26 Apr
2,500
30
0.2
-------
EXPERIMENT VI
No studies were conducted during the summer of 1973 due to major
modifications and repairs undertaken for the system. A 2-foot vertical
wall of redwood planks was constructed along all banks of North Pond ex-
cept in those areas where the bank was not protected by an oyster shell
layer (Figure 5). A forced-air aeration system was installed during
this period as previously described. Water from Humbojdt Bay was intro-
duced into both ponds during late August. After draining North Pond
several times to adjust the aeration system, water from the oxidation
pond was added to both ponds to develop a salinity of about 25 o/oo.
This was to test Power's^0 hypothesis that amphipod growth and survival
would be maximized at this salinity level. In early October, salinities
were reduced to about 15 o/oo. On October k, live-car bioassays were
started, with no mortalities recorded through October. On 2 November
1973, 5,000 coho fingerlings were introduced into both ponds. After k$
days rearing, over 80% of the fingerlings were recovered for release in-
to Humboldt Bay. Very few of the salmon had become smolts. Because
there were no residual stocks of amphipods left within the pond follow-
ing summer construction, nor were there amphipods occurring naturally
in Humboldt Bay during introduction of saltwater, very few of these
forms were available as food for the salmon. Consequently, larger sal-
mon actually showed a slight reduction in weight although smaller fish
retained or even slightly improved their condition during the rearing
period.
SALMON PRODUCTION
POND REARED FISH
The production of salmon from the system varied widely (Table 4).
For coho fingerling planted in late summer and fall periods (Experiment
IB, IVB, VI) the trend has been from moderate to high survivals, coupled
with an inverse trend in actual fish production (high to low). The
single experiment with coho fingerlings reared during a summer period
(Experiment III) showed a low survival and low production of salmon but
a high survival and high production of other species of fish. Both sur-
vival and production of chinook salmon from fry plantings were low, al-
though the chinook grew fast and smolted (Experiment II and V).
PEN AND LIVE-CAR REARED FISH
The survival and growth of salmon reared in pens and live-cars was
often markedly different, usually greater, than salmon living unre-
stricted in the ponds, indicating a potential growth and survival great-
er than actually found for the ponds to date.
Pen
Pens constructed over pond substrates were designed to exclude
fish over these substrates. During Experiment IB, on October 20, 1971,
in error 50 coho salmon were placed into Exclusion Pen NC (gravel sub-
strate, Figure 2). Electric shocking, and seining, recovered 35 salmon.
When the pond was drained on 22 January 1972, 17 fish were recovered.
182
-------
So
Uj
Table k.
IB
Summary of production— in fish-rearing experiments, June 1971 - December 1973, in
pilot-fish pond system using saltwater fertilized with advanced secondary treated
effluent from City of Arcata oxidation pond.
Exp. pond
No.
Species,
Size of Fish
Days
Reared
Percent
Survival
product ion—
as kilograms
per hectare
per day
Remarks on
experimental
result
IA North Coho fingerling
South Coho fingerling
0
North Coho fingerling
I I North Chinook fry
III North Coho fingerling
55
3
k
Unstable water and bottom
conditions; temperatures
consistently over 20 C
Salinities over 32 o/oo
and high temperatures;
high density of topsmelt
and stickleback
6.8 High density of planting
induced intensive preda-
tion by bi rds
0.05-0.07 Mortality possibly due to
over-rearing.
0.4 Nature of mortality unde-
termined. Food primarily
consumed by other species
-------
Table *». (Continued)
Exp. Pond
No.
Species
Size of Fish
Days Percent
Reared Survival
Production—
as kilograms
per hectare
per day
Remarks on
experimental result
North Topsmelt, stickle-
back, sculpins
IVA North Coho finger ling
IVB North Coho fingerling
V North Chinook fry
South Chinook fry
VI North Coho fingerling
South Coho fingerling
86
30-119
30-119
high
Bk
1-6
0,1-2
96
78
3,7
trace
trace
loss
loss
Production entirely from sur-
vival of eggs and larvae in-
troduced with saltwater from
Humboldt Bay
Mortalities correlated with
period of low dissolved
oxygen
Experiment primarily to
assist in bird predation
study
Mortality possibly from
over-rearing
Mortality possibly from
over-rear!ng
Sufficient amphipod popula-
tion did not develop in
system
I/ Production defined as the change in weight of those fish surviving from planting into ponds
~ until recovered during pond draining.
-------
Table 5. Comparison of survival of chinook fry planted into ponds
and reared in exclusion pens (Experiment V).
Number planted
Number Recovered
Percentage
Surface Area
(Square meters)
North pond
Exclusion Pond
Pen Over
Gravel
77 7,500
40 85
51 1
4 1,500
South Pond
Exclusion Pond
Pen Over
Gravel
77 7,500
Ik 12
18 0.1
4 1,500
Table 6. Comparison of survival of coho fingerling salmon planted
into ponds and reared in exclusion pens (Experiment VI).
North Pond
Exclusion Pond
Pens
Number planted!7 56 5,000
Number Recovered 46- 4,800
Percentage 82 9«
South
Exclusion
Pens
56
56
100
Pond
Pond
5,000
3,900
78
M 7 unmarked and 7 LV marked coho fingerlings planted into each
~~ of four pens.
2/ 8 of 10 mortalities from pen NB (Hookton Soil).
185
-------
This represented virtually no mortality during a 92-day rearing period.
At the same time, live-car reared fish showed 20-30 percent mortalities,
compared to a 45 percent mortality suffered by the salmon released into
the pond.
Based on this experience, we used the pens to study the effect of
having different densities of salmon feeding over the substrates in Ex-
periment V. Our examination of the pen bottoms failed to disclose small
escape route for small fish under the corners of the pen frames except
for the pens over gravel. Consequently salmon escaped through these
holes during pond draining, and an absolute count of salmon surviving
was made from the pens over gravel in each pond (Table 5). In both
ponds, survival of Chinook fry in the pens was strikingly higher than
the generally low survival of the same lot of fish planted into the
ponds.
During the summer of 1973, each pen bottom was made secure. At
this time pen NB was relocated over fresh Hookton soil. We then planted
each pen at the same density of salmon per unit area as we did in the
main ponds (Experiment VI). All salmon survived in South pond pens,
while mortalities in North Pond pens were mainly associated with fish
grown over raw Hookton Soil (Table 6). High survival in general made
it impossible to draw any conclusions on substrate effect. The new
Hookton soil probably did not provide sufficient food for the salmon.
Live-Car
For coho fingerling salmon, the confinement of salmon in pens sus-
pended away from the pond bottom resulted in less growth than salmon
reared in cages located on pond substrates. In Experiment VI, both LV
and unmarked lots of salmon were consistently smaller when grown in
cages than when reared in pens over bottom substrates (Table 7). This
effect was first noted in Experiment M when the average size of the sal-
mon in North pond was 12.4 grams in pen located over gravel in compari-
son to 15.0 grams for the salmon reared rn the pond. |t was not possible
to discern whether one substrate was more beneficial over another in
Experiment VI because individual fish were not measured for weight or
length before being placed into pens.
fn the single experiment with chinook fry lots reared in cages and
pens (Experiment V), the rate of growth was slower in cages than in the
pond but the actual production of wet weight of salmon was higher in the
cages (Table 8). These production rates were in the range exhibited by
coho fingerling in experiments IB and IVB (Table 4).
CAUSES OF MORTALITY
OXYGEN DEPLETION
The use of oxidation pond effluent to fertilize seawater produces
786
-------
Table 7. Comparison of average weight in grams of small and large-sized coho fingerling salmon
reared in cages and pens (Experiment VI).
Pond Rearing Site
North Insert and
Culture Raft
Insert Live-Car
Shel 1 Pen
Hookton Soi 1 Pen
Gravel Pen
Mud Pen
South Insert and
Culture Raft
Insert Live-Car
Shel 1 Pen
Hookton Soi 1 Pen
Gravel Pen
Mud Pen
Weight by group of fingerling
Per
k Oct
2 Nov
2 Nov
2 Nov
2 Nov
2 Nov
k Oct
2 Nov
2 Nov
2 Nov
2 Nov
2 Nov
iod
- 15 Dec 73-7
- 15 Dec 73
- 15 Dec 73
- 15 Dec 73
- 15 Dec 73
- 15 Dec 73
- 16 Dec 73-
- 16 Dec lk
- 16 Dec lk
- 16 Dec Ik
- 16 Dec 7*4
- 16 Dec lk
Days
73
kk
kk
kk
kk
kk
lk
kS
k5
k$
kS
kS
Small
(LV)
6.3 (2k)-
5.3 (23)
7-6 (5)
9.0 (5)
8.0 (7)
7.5 (7)
k.2 (2k)
k.8 (30)
8.0 (7)
6.8 (7)
9-5 (7)
8.5 (7)
Large
(Unmarked)
_
17.6 (26)
27.1 (7)
1.0 (1)
18.0 (7)
18.6 (7)
13.8 (30)
17.2 (7)
15.9 (7)
19.1 (7)
19.6 (7)
-------
Table 7. (Continued)
do
00
Pond Rearing Site
Period Days
South Crab Rearing Pervi' 2 Nov - 16 Dec 7** **5
Weight
Sma 1 1
(LV)
6.6 (21
by group of fingerling
Large
(Unmarked)
1 18.0 (2)
I/ Small salmon without a mark were placed in Insert live-car on k October, reared until
~ 2 November, then moved to hanging pen in Culture Raft.
2/ Number of salmon recovered at end of rearing period shown in parenthesis. Twenty-five
"" salmon were placed in Insert live-car. Seven salmon each of small and large-sizes were
placed into pens.
3/ Salmon entered pen on their own and were recovered on draining pond.
-------
Table 8. Comparison of rates of production of wet weight of salmon
of unmarked chinook fry reared in pens and cages, North
Pond, Experiment V.
Stock of chinook salmon
ETarTy' RunLate Run
Large Pen on Large Small
Live-Car Gravel Live- Live-
Bottom Car Car
A. Experimental Factors
Surface area of rear-
ing site (square
meters) 0.4 4.0 0.4 0.1
Planting density num-
ber of fish per
square meter) 65 20 250 250
Length,of rearing (days) 49 70 70 70
B. Percent survival 100 49 51 40
C. production rates (kilograms per hectare per day)
I. Based on gain in
weight of surviving
salmon 11 3.4 10 10
I|. Based on net gain
in weight of salmon 8.5 2.8 4.0 1.4
759
-------
a highly fertile solution. Consequently, the high oxygen demand of the
system can produce low oxygen values in a very short time period when
cloud cover is heavy or aeration systems are inoperative. Periods of
low oxygen level during mid-October 1972 (Figure 9) caused heavy mor-
talities during Experiment IV. Other than this instance, and the ini-
tial unstable conditions during Experiment (A, aeration units have been
able to avoid stratification in the ponds and to maintain oxygen levels
sufficient for juvenile salmon.
HEAVY METALS
Data on levels of metals (acid-soluble Cu, Cr, Fe, Na, Ni and Zn)
in the pond bottom were available from a study by GrossZS, of fifteen
locations investigated in the local marine areas, ten were either in or
near the North and South fish ponds. Two sampling sites were located
in the fish ponds, one each In North and South ponds. The sediments of
the oxidation pond, and the fish ponds, contained unnaturally higher
amounts of Zinc than all other locations tests (5 samples ranged from
85 to 360 ppm, one sample 25 ppm as opposed to all other areas which
ranged from only 2-43 ppm).
There has been no study yet to ascertain if heavy metals in the
pond sediments, which undoubtedly represent an area of accumulation due
to the operation of the oxidation pond, are entering the food chain of
the salmon. A major source of food consumed by the salmon has been two
species of amphipod (Corophium sp., and Anisogammarus confervicolus)
but these have not been analyzed for heavy metal contendThe higher
survival of salmon reared in live-cars and exclusion pens, suggest this
possibi1ity,
BIRD PREDATION
Although methods of controlling loss of fish to birds at rearing
facilities has been reported extensively in the literature (Blankin-
sn'P27), little data are available on the numbers of fish actually
eaten. Thus the pilot project at Humboldt Bay has provided an opportu-
nity to study bird predation on unprotected ponds. These data will al-
low for comparison of rate of predation on modified ponds, and eventu-
ally provide data on the design of production facilities.
Bird predation as estimated by studies undertaken by Blankinship
on unmodified ponds showed a variation of from 2-24 percent for coho
fingerling (Table 9). The maximum value was associated with an experi-
ment in which fish were under stress, whereas the minimum value was
from an experiment in which the density of salmon planted was low and
their survival poor. For Experiment VI modifications to North Pond in
the summer of 1973 were to deter predation by species of birds that feed
along the shore, however, very few birds visited either the modified
(North) or unmodified (South) pond, so that effectiveness of the pond
modifications could not be assessed from this study.
790
-------
Table 9. Estimated percentage of salmon planted into North pond
consumed by birds (from Blankinship 1973).
Experiment Species and Size Percentage of
Number of Salmon Salmon Consumed
IB Coho finger ling 13~~
I| Chinook fry ^
I|| Coho fingerling 2
(Stickleback, topsmelt) (8)
IVA Coho f ingerl ing 2*»-
IVB Coho fingerling 12
V Chinook fry no study
V| Coho fingerling trace
I/ Minimum estimate from limited hours of observation near end of
"~ experiment.
2/ Maximum estimate as fish were under stress during parts of the
experiment causing higher predator success than occurs on
unstressed salmon.
797
-------
A low predation rate was recorded in experiments with chinook fry.
These experiments (II, V) had low survival thus it was not possible to
know if bird predation was due to unavailability of chinook to birds or
due to differences in behavior of chinook fry as compared with coho
fingerlings.
OVER-REARING
There was evidence that we over-reared chinook salmon. During Ex-
periment I), 1/2-meter ring nets were fished at night in North pond to
obtain salmon for study of their food habits. From April 18 through May
2k, the average catch per haul was from 2.8 to 5.5 salmon (k-6 hauls per
sampling). On May 31, 7 hauls only produced a mean catch of 1.0 salmon.
During Experiment IV, studies on fishing ability of 2-cubic feet wire
mesh traps with a single funnel entrance caught 28 salmon when fished
continuously for 2 days in early April. From 17 May until 25 May, the
same traps caught no salmon during this period (8 days).
The exact reason for the sudden loss of salmon in the ponds during
late May periods is not known but may be correlated with physical and
chemical parameters of the water in addition physiological changes asso-
ciated with the migratory habits of the species (Reimers26). Hydrogen
ion concentrations (pH) tended to fluctuate between 7 and 8 during the
beginning of these experiments, then rose to stabilize around 9.5 units.
Along with this trend, with the general increase in average daily temper-
ature and increased sunshine water temperatures approached 19°C in both
Experiments II and V. Smolts recovered in experiments II and V were
much larger than the average size reported for smolts of chinook salmon
in the Mad River (70 mm fk. len., Taniguchi2?). Chinook salmon smolting
may require a different or more abundant food source than the ponds were
providing.
DISEASE
Infectious diseases appeared to be a minor factor as a cause of
mortality. This opinion was based on the fact of relatively high sur-
vival of salmon reared in floating cages and exclusion pens during ex-
periments when the same stock of salmon reared in the ponds showed low
survival. Richness of the diet produced in the ponds for salmon may be
a possible cause of mortality (nutritional disease).
FOOD
Gammarid amphipods have been the major food item in the diet of our
pond-reared salmon (Powers30). Tube-dwelling amphipods (Corphium) un-
doubtedly will become a major component in the pond fauna when some form
of tidal or flow-through operation occurs. Although productivity of the
ponds in terms of salmon biomass appears to be declining (Table 4), re-
sults from Experiment VI should be discounted. Lack of amphipods during
Experiment VI resulted from complete drying of all areas of the pond
during a long summer of repair and construction, the elimination of
792
-------
holding areas for amphipods, by replacing the wood construction of fish
collecting basin with concrete construction, and finally from a virtual
absence of amphipods in Humboldt Bay in September when the ponds were
filled for Experiment VI. Undoubtedly the successful management of our
wastewater aquaculture system will require as much understanding of the
biology of the amphipods as that of the salmon.
CONCLUSIONS
Coho fingerling and chinook fry can be successfully reared in ad-
vanced secondarily treated domestic wastewaters mixed with saltwater.
The best results in our studies were in mixtures producing 10-15 o/oo
salinity (roughly two parts effluent to one part saltwater).
Experiments with coho fingerling reared in late-fall to winter
have not carried these salmon to complete smolting of all fish because
of our need to have the ponds ready for chinook salmon experiments, our
primary target species. Results of these rearing experiments suggest
the management possibility of enhancing estuarine survival through such
an intermediate period of brackish-water rearing. With completion of a
recirculating aquarium system next to our ponds for fish holding and
marking, we will begin to test this hypothesis by marking all coho sal-
mon reared, and by holding them for release under the most favorable con-
ditions possible.
The single experiment with coho fingerling in the summer indicated
that our fish had not grown to sufficiently large size prior to planting
to harvest the marine fishes which had grown rapidly from eggs and lar-
vae introduced from Humboldt Bay. Hayes25 noted that steelhead in Big
Lagoon were mainly yearling fish that had moved into the lagoon during
spring months. Future summer rearing will use larger fish (yearling
rainbow, steelhead, or coastal cutthroat trout).
Chinook fry have grown rapidly and smolted, although the overall
survival achieved would not make the system as a feasible alternative
to existing culture methods. The higher growth and survival of ch.nook
reared in pens and live-cars than fish reared in the open ponds, indi-
cate that the full productive capacity of the system has not yet been
attained. Recent laboratory studies on bluegill sunfish have indicated
the feasibility of increasing the ratio of surface area to water volume
for development of more fish food organisms (Pardue^ ). The effect has
been noted during studies of artificial reefs in marine waters of Hum-
boldt Bay (DeGeorges32j prince33) Lambert^). Any such underwater
structures may also have utility in decreasing interspecific competition
that we can expect in the ponds (Payne35} Reimers ).
The saltwater-wastewater mixture may have some therapeutic effect
as gross observations of our mortalities have not indicated any ,nfec-
tioCs disease. Vibrio can be especially serious in west-coast man-
culture (Fryer20)^
793
-------
Reliable aeratfon systems are essential in wastewater mariculture
because of the rapidity of oxygen depletion which can occur under cer-
tain environmental conditions (heavy fog or cloud cover in particular).
Forced-air aeration appears most favorable, and probably will improve
pond conditions by stripping ammonia produced by salmon metabolism.
FUTURE PLANS
With recent passage in California of initiative legislation set-
ting up stricter controls on coastline development, the area available
for mariculture could be sharply curtailed, especially as we are lack-
ing comparative data on economic returns with other possible types of
land uses. Future expansion of mariculture within the confines of the
oxidation pond, or into the remaining portion of a now abandoned land-
fill refuse site immediately to the west of the Arcata oxidation pond,
could take place with land-use conflicts. A master plan for the oxi-
dation pond area has been submitted to the City of Arcata which in-
cludes expanded mariculture facilities (Figure 1), developing a simi-
lar plan for the land-fill refuse site.
Wastewater stabilization lagoons, fertilized fish ponds, and eu-
trophic natural waters all contain high numbers of algal cells. Where
lagoons and ponds are discharged into receiving waters, water quality
standards on BOD and particulate matter may not be attainable without
removal of algal cells. We are undertaking studies on mussels as a
possible method of biological scrubbing to remove algal cells and
pathogens. Successful bivalve scrubbing could reduce the high cost of
chlorination required to meet the California State Water Resources Con-
trol Board22 standards for a receiving water where shellfish harvest
for human consumption is likely (median total coliform concentration
shall not exceed 70 per 100 ml, and not more than 10 percent of the
samples shall exceed 230 per 100 ml). Recently, a standard of 0.2 ppm
residual chlorine has also been applied, thus increasing the costs of
treatment by standard physical-chemical means considerably.
We have become interested in the possibility that reducing the
amount of treated wastewaters into Humboldt Bay might actually reduce
the biological productivity of this estuarine system. Estuaries in
northern California are subjected to hugh freshwater inflows during
the winter periods of heavy rainfall. They are, therefore, ecological-
ly adjusted to intermittent periods of reduced salinity. Humboldt Bay
has an extremely high flushing volume (Skeesick^°). Near-shore water
of the Pacific Ocean are generally high in nutrients, especially during
periods of off-shore upwelling (Allen*?)_ Thus the addition of well-
treated wastewaters into the system would have beneficial effects.
Fortunately, the possibility of reducing a beneficial effect of a well-
treated wastewater on a receiving body of water has been recognized by
the California State Water Quality Control Board^°).
In summary, our future program in wastewater maricultre falls
794
-------
into four broad categories. First, we will continue empirical studies
to obtain the maximum production of salmon smolts to allow a feasibility
study of a production system. Second, we plan to obtain permission for
expansion of mariculture ponds into areas adjacent to our present loca-
tion. Third, we have formed an interdisciplinary team of specialists
on the university staff to undertake investigations within their area
of competence as an effort in applied ecosystem analysis. Finally, we
will expand our preliminary studies on biological methods for removing
algae and particulate matter in our effluents through polyculture.
LITERATURE CITED
1. Allen, G. H. 1969. A preliminary bibliography on the utilization
of sewage in fish culture. FAO, Fish. Cir. No. 308, 23 pp.
2. . 1970. The constructive use of sewage, with particular
reference to fish culture. FAO Tech. Conf. on Marine Pollution
and its Effects on Living Resources and Fishing. Rome 9/18
Dec. 1970. FIR: MP/70/R-13. (_m Marine Pollution and Sea
Life. Survey of Problems and Treatments, Fishing News (Books)
Ltd, Surrey, England, 1973).
3. Mortimer, C. H. and C. F. Hickling. 195^. Fertilizers in fish
ponds. London, Her Majesty's Stationery Office, Colonial
Office, Fish. Publ.: No. 5, 155 pp.
4. Law, J. P. 1968. Agriculture utilization of sewage effluent and
sludge. Project Report. Water Poll. Control Admin., EPA,
Water Quality Office, Washington, D. C. 89 pp.
5. Wilson, C. W. and F. E. Beckett, Eds. 1968. Municipal sewage ef-
fluent for irrigation. Ruston, Louisiana, The Louisiana Tech
Alumni Foundation. 169 pp.
6. McKinney, R. E., J. N. Dornbush, and J. W. Vennes. 1971. Waste
treatment lagoons - state of the art. EPA, Water Poll. Cont.
Res. Series, 17090 EHX 07/71, 152 pp.
7. Ryther, J. H., W. M. Dunstan, K. R. Tenore and J. E. Huguenin.
1972. Controlled eutrophication-lncreasing food production
from the sea by recycling human wastes. Bio Science, 22(3):
144-152.
8. Huggins, T. J. and R. W. Backman. 1969. Production of channel
catfish (Ictalurus punctatus) in tertiary treatment ponds.
U. S. Clearing House, Fed. Sci. Tech. Info. PB Report No.
190165, 122 PP.
9. Hal lock, R. J. and C. D. Ziebell. 1970. Feasibility of a sport
fishery in tertiary treated wastewater. Jour. Water Poll.
Cont. Fed., 42(9): 1656-1665.
795
-------
10. Trimberger, J. 1972. Production of fathead minnows (pimephales
promelas) in a municipal waste water stabal izat ion system.
Michigan Dept. Nat. Res., Fish Div., Unpublished. 5 pp.
11. Anon. 1972. Fish raised inwastewater lagoons. The American
City, 87(6):
12. Deaner, D. G. 1970. Public health and water reclamation. Re-
print of paper presented to Annual Meeting of the Sacramento-
San Joaquin, Calif. Water Poll. Control Assn., June, 1970.
7 PP.
13. . 1971. Cal ifornia Water Reclamation Sites 1971. Calif.
State Dept. Public Health, Bur. Sanit. Eng., 63 pp.
}k. Jopling, W. F., D. G. Deaner, and H. J. Ongerth. 1971 . Fitness
needs for wastewater-reclamat ion plants. Jour. Amer, Water
Works Assoc., 63(10): 626-629.
15. DeWitt, J. W. 1969. The pond, lagoon, bay estuarine, and im-
poundment culture of anadromous and marine fishes, with empha-
sis on the culture of salmon and trout, along the Pacific
coast of the United States, U. S. Depart. Comm., Econ. Develop,
Adm., Tech. Assist. Project, 36 pp.
16. Hansen, R. J. 1967. A study of some physical and chemical en-
vironmental features of a large sewage oxidation pond. MS
Thesis in Fisheries, Humboldt State College, 133 pp.
17. Hazel, C. R. 1963. Chlorophyll and non-astacin pigment concen-
trations and photosynthetic oxygen production in a sewage
oxidation pond. MS Thesis in Fisheries, Humboldt State Col-
lege, 119 pp.
18. Allen, G. H. , Guy Conversano, and B. Colwell. 1972. A pilot
fish-pond system for utilization of sewage effluents, Hum-
boldt Bay, northern California. Calif. State Univ., Hum-
boldt. HSU-SG-3, 25 pp.
19. t and P. J. O'Brien. 1967. Preliminary experiments on
- th~e~accl i mat izat ion of juvenile king salmon, Oncorhynchus
tshawytscha, to saline water mixed with sewage pond effluent.
Calif. Fish and Game, 53(3): 180-184.
20. Fryer, J. 1973. Need for pilot demonstration projects in aqua-
culture. Proc. Assoc. Sea Grant Program Inst., Nat. Conf.,
Univ. Delaware, October, 1973. In press.
21. Leitritz, E. 1959. Trout and salmon culture - hatchery methods.
Calif. Dept. Fish and Game, Fish. Bull. No. 107. 169 pp.
796
-------
22. California State Water Resources Control Board. 1972. Water
quality control plan for ocean waters of California, July 6
1972. 13 pp.
23. Allen, G. H. 1973. Rearing Pacific salmon in saltwater ponds
fertilized with domestic wastewater July 71-June 1972. Hum-
boldt State University Coherent Area Sea Grant Program.
Data Report, 88 pp.
2k. Joseph, J. 1958. Studies of Big Lagoon, Humboldt County, Cali-
fornia, 1956-58. MS Thesis in Fisheries, Humboldt State Col-
lege, 137 pp.
25. Hayes, J. M. I960. A study of the salmonids and some other fish-
es of Big Lagoon, Humboldt County, California. MS Thesis in
Fisheries, Humboldt State College, 146 pp.
26. Reimers, P. E. 1973. The length of residence of juvenile fall
chinook salmon in Sixes River, Oregon. Oreg. Fish Comm.,
Res. Repts., 4(2): 43 pp.
27. Blankinship, T. E. 1973. Impact of birds on salmon populations
at a rearing pond, Humboldt County, California. MS Thesis
in Wildlife, Humboldt State University, 83 pp.
28. Gross, Craig. 1972. The distribution of acid-soluble Cu, Cr,
Fe, Na, Ni and Zn in sediments from various environments of
deposition in Humboldt County, California. Senior Thesis.
Department of Geology, Humboldt State University. 23 pp.
29. Taniguchi, A. K. 1970. Interval of estuarine residence and out-
migration of the juvenile chinook salmon in the Mad River,
California. MS Thesis in Fisheries, Humboldt State College,
87 pp.
30. Powers, J. E. 1973. The dynamics of a population of Anisogamma-
rus confervicolus (Amphipoda): a computer simulation"! MS
ThesTsin Fisheries, Humboldt State University, 111 pp.
31. Pardue, G. G. 1973. Production response of the bluegill sunfish,
Lepomis macrochirus Rafinesque, to added attachment surface for
fish-food organisms. Trans. Amer. Fish. Soc., 102(3):
622-626.
32. DeGeorges A. 1972. Feasibility of artificial reefs in interti-
dal waters. MS Thesis in Fisheries, Humboldt State Univer-
sity. 102 pp.
797
-------
33. Prince, E. D. 1972. The food and behavior of the copper rockfish,
Sebastes caurinus Richardson, associated with an artificial
reef in South Humboldt Bay, California. MS Thesis in Fisher-
ies, Calif. State Univ., Humboldt. 102 pp.
3^. Lambert, R. T. 1973. Seasons of attachment and settlement on
various substrates and abundance of colonizing organisms on
an artificial reef in Humboldt Bay, California. MS Thesis
in Fisheries, Humboldt State University. 118 pp.
35. Payne, T. R. 1972. Study on the development of the prior resi-
dence effect in rainbow trout (Salmo gairdneri). MS Thesis
in Fisheries, Humboldt State University"! 25 pp.
36. Skeesick, D. G. 19&3. A study of some physical-chemical char-
acteristics of Humboldt Bay. MS Thesis in Fisheries, Hum-
boldt State College. H*8 pp.
37. Allen, 6. H. 196*+. An oceanographlc study between the points of
Trinidad Head and the Eel River. Calif. State Water Quality
Control Board, Publ. No. 25: 125 pp.
38. California State Water Resources Control Board. 1973. Research
needs for water resources control In California. Publ. No.
**8: *+8 pp.
198
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AQUACULTURE AS A MEANS TO ACHIEVE EFFLUENT STANDARDS
by
Mark S. Coleman, James P. Henderson,
H.G. Chichester and R. LeRoy Carpenter*
INTRODUCTION
Effluent Standards
The Federal Water Pollution Control Act Amendments of 1972**
required that all publicly owned treatment works achieve effluent
limitation based on secondary treatment as defined by the Administrator
of the Environmental Protection Agency. The Act also required that
the State classify all stream segments as either effluent limited or
water quality limited. Discharges to effluent limited segments must
meet the defined^ secondary treatment requirements whereas discharges
to water quality limited segments must generally meet more stringent
treatment requirements. Subsequent to publication of the effluent
limitations associated with the definition of secondary treatment,
the Environmental Protection Agency determined2 that waste stabiliza-
tion ponds (lagoons) as presently designed would meet the BOD5
limitation of 30 mg/1, but would not meet the suspended solids limi-
tation of 30 mg/1 or the fecal coliform limit of 200/100 ml without
improved pond design and operation and additional treatment steps
for algae removal and disinfection. Additionally, specific stream
segments in many states were designated3 as water quality limited
and require that effluent discharges to those streams have BOD5
concentrations of significantly less than 30 mg/1^. As several
thousand of these inexpensive and simply operated waste treatment
facilities exist, particularly in smaller communities in the less
populated areas of the country, it was highly desirable that a means
be developed whereby these facilities would meet the various upgraded
requirements.
Lagoon Treatment
Lagoon treatment systems rely on biological systems which de-
grade and stabilize organic compounds in wastewater. A conventional
*0klahoma State Department of Health, Oklahoma City, Oklahoma
**Public Law 92-500
799
-------
scheme of this process is demonstrated in Figure 1. Prior to lagoon
treatment, sewage may receive no. treatment at all, mechanical treat-
ment ranging from primary to a high degree of secondary treatment, or
extensive biological treatment. Numerous modifications of lagoon
design exist and a wide range are in current use.5,6
The gross biological steps in this type of common treatment
system are: (1) bacterial (anaerobic and aerobic) decomposition of
organic wastes resulting in component molecules (plant nutrients)
being released into the water; and (2) algal utilization of nutrients
producing rapid growth and large populations.7,8,9,10 The algal
phase of the process constitutes the basic mechanism of separation
of the nutrients (primarily nitrogen, phosphorous, and carbon) from
the water. Proposed mechanisms (Figure 2) to upgrade effluent quality
from lagoons tend to be physical in scope and include settling, flocu-
lation, and filtration aimed toward the removal of the algal cells.
Removal of the algae results in lower concentrations of suspended
solids and removal of the elemental constituents comprising their
organic mass."
Proper design and maintenance of such a system should provide
a high degree of waste treatment. However, these types of treatment
mechanisms have some undesirable attributes which are of concern.
The algal removal processes involve greatly increased construction,
operational, and maintenance costs. In addition, waste products
are produced requiring further disposal.11,12
Personnel of the Oklahoma State Department of Health have been
conducting a preliminary research project since 1970 in an attempt
to attack and ameliorate the problems of algal removal and to upgrade
the quality of lagoon effluents. The basic assumption of the project
is that a biological means of removal exists for the biological
phenomenon of algal production. Current systems are biological to
the algal removal point. The physical-chemical treatment phase for
algal removal is replaced in the system undergoing study by employing
a further biological segment based on herbivorus or filter-feeding
fishes.
This biological removal concept is presented in Figure 3.
Although either an advanced biological treatment system or an ad-
vanced physical-chemical treatment system will produce an effluent
of high quality, a significant point of this alternative is that the
removal of algae through the ecological food chain will produce a
useful product in the form of fish as opposed to a product requiring
further disposal. Many alternatives for the use of fish are avail-
able ranging from reduction to animal food, to sale of live fish
for bait, restocking or forage.13
200
-------
' I
HAW WAS F»
BACTF RIAL
Ot COMPOSI TION
NUTRIENT
RICH
WATER
PRIMARY
PRODUCTION
ALGAE
LADEN
EFFLUENT
Figure 1 Schematic Representation of a Typical Waste Oxidation Pond
-------
LAOOON NO. !
LAQOON NO. 2
ALGAE
LAOEN
ENT
1 1
MECHANICAL
FLOCl/LATION
AND
SEPARATION
CHEMICAL
FEED
POLISHED
EFFLUENT
• CHLORINATION
Figure 2 Schmatic Representation of a Typical
Physical-Chemical Advanced Waste Treatment System
-------
i -
•
•
OUTLET STRUCTUK1
KAW WA\ I I
BACTERIAL
ULCOMPOSITION
NUTRIF.MT
WAII II
PRIMARY
PHOOUCTION
ADVANCED
HU ILOCilCAL
1 l!( Al MI.NT
F IStt PRODUCTION
, POLISHED
EFFLUENT
Figure 3 Schematic Representation of Operation of an Advanced Biological Treatment System.
-------
Project History
As the project began to take form in 1970, several species of
fish were cultured in the laboratory to determine viability. Thirty
gallon aquaria containing wastewater at various levels of treatment
were utilized in this preliminary effort. Water was changed on a
weekly basis. Species cultured successfully included carp, goldfish,
fathead minnow, golden shiner, black bullhead, channel catfish,
mosquitofish, bluegill, green sunfish, largemouth bass and Tilapia
nilotica.
In the spring of 1971 it was decided to apply a larger scale
test of fish viability in actual oxidation ponds. Arrangements
were made with the City of Oklahoma City to use the Quail Creek
Sewage Lagoon system located northwest of Oklahoma City. A diagram
of this system is presented in Figure 4. It consisted at that time
of a two-cell, serially operated system receiving approximately
750,000 gallons/day of raw domestic sewage. The facility utilized
the'fiinde Air-Aqua treatment process whereby diffused air was intro-
duced through subsurface air lines. Fish cages were placed near the
effluent end of the second cell and anchored to a cable stretched
the width of the pond between two air lines. Approximately 200
individuals of promising species, including channel catfish, bluegill,
and largemouth bass were placed in the cages where the bench scale
viability studies were verified.
SYSTEM DESIGN AND OPERATION
Facility Description
When the facility was originally built, it was planned to
eventually utilize three separate sets of the two cell Hinde system.
Sufficient funds existed to construct all needed cells in the initial
construction. The plan was to add on first facultative lagoon capa-
city and add aeration as the collection system expanded. By early
1973 about 1 mgd of raw domestic waste was receiving conventional
aerated treatment in the first two cell set of the three set system.
For experimental purposes, it was determined to utilize the four non-
aerated and unused ponds in conjunction with the existing aerated
system to form a six cell, serially operated system. (Figure 4)
Accordingly, in May, 1973, 25,000 two to four inch channel catfish
were stocked in the third cell and an additional 25,000 into the
fourth cell. The fifth and sixth cells received 85 pounds (about
1500) Rolden shiner adults equally divided between the two cells. An
additional stocking of approximately 5 pounds of fathead minnows were
Introduced into the third cell in July, 1973. Also in July, 175
three inch Tilapia nilotica were placed in the third cell.
204
-------
Nj
Figure 4 Schematic Representation of Quail Creek Lagoon System
-------
Problems arose in the system when black bullhead, green sunfish
and mosquitofish already present in the aerated cells, contaminated
the remainder of the system. However, the resulting polycultural
situation lent itself to gleaning data on a wider food web than
originally intended.
Analytical Methods
Water sampling consisted of removing 2 liters of the raw
waste and effluent of each cell on a weekly basis. Standard labora-
tory analyses^ were conducted by the Oklahoma State Department of
Health and City of Oklahoma City. Bacteriological sampling consisted
of removing 100 ml of water from the raw waste and effluent of each
cell on alternate weeks. Fish population analyses consisted of a
preliminary food habits investigation and biomass estimates. Estimates
of biomass were made from seine hauls encompassing a closed known
area of each cell. Mean weights were taken for samples of 100 fish
and applied to estimated numbers. Food habit data were taken by
excising stomachs of various species at the isthmus and duodenal
sphincter. Identification of stomach contents was made in the labora-
tory utilizing standard methodology.
RESULTS AND DISCUSSION
Analysis of Water
A summary of water analyses are presented in Table 1 and are
the average of weekly samples from June 6, 19-3 to October 3, 1973.
The secondary treatment standard for BOD5 of 30 mg/1 was met in the
effluent from the second cell and fell significantly throughout the
remainder of the system. The remaining secondary standards for
suspended solids of 30 mg/1 and fecal coliform of 200/100 ml were
met in the effluent of the fifth cell.
With respect to suspended solids, it is important to note that
from the second cell through the remainder of the system approximately
half of the suspended solids were non-volatile. As the newly filled
lagoons have sustained considerable bank erosion due to wind action,
it is felt that this, when stabilized, will reduce suspended solids.
Turbidity data substantiate this contention. Since the volatile
portion of the suspended solids is primarily composed of algal cells,
a primary target of this research, it is anticipated that the volatile
fraction will decrease more rapidly as the system is optimized.
The nitrogen forms are of special interest due to the overall
removal efficiency by this system. Ammonia was reduced below 1.0 mg/1
N in effluent from the first cell. It is also significant that of
206
-------
Table 1 Mean Values of Weekly Analyses of Water Samples from the Quail Creek Lagoon System.
Samples were Collected June 6, 1973 through October 3, 1973.
Parameters
Raw
o
NJ
Biochemical Oxygen Demand
(5 day) 184
Suspended Solids
Volatile Suspended Solids
Total Nitrogen (as N)
Nitrite Nitrogen (as N)
Nitrate Nitrogen (as N)
Ammonia Nitrogen (as N)
Organic Nitrogen (as N)
Total Phosphorous
(asP)
197
131
18.94
0.07
0.20
12.67
6.10
9.01
Fecal Col. form/1 00 ml 3.05x106
Turbidity
pH (standard units)
55
7.3
47
79
54
10.50
4.54
1.00
0.91
4.05
9.87
10880
15
7.8
24
71
45
7.04
0.96
2.31
0.40
3.37
7.97
1380
23
8.2
17
52
34
6.65
0.86
1.79
0.31
2.69
5.80
322
25
8.6
14
54
27
3.97
0.34
0.79
0.28
2.56
3.66
15
42
8.9
9
26
13
3.13
0.34
0.31
0.10
2.28
3.01
15
17
8.4
6
12
6
2.74
0.16
0.29
0.12
2.17
2.11
20
9
8.3
'Data reported in tng/1 except where noted.
-------
total nitrogen remaining in the system, the majority from the third
through sixth cell was organic nitrogen. This organic fraction was
likely present in algal cells. Thus with further refinement of the
system, this should ultimately be reduced to even lower levels.
Phosphorus showed good reduction throughout the system to a
low of 2.39 mg/1 in the final effluent. There were doubtless a
variety of factors involved in this reduction, including removal of
algal cells. It is likely that at least a part of this removal was
due to the formation of a calcium-magnesium-phosphate sludge under
the conditions of the high pH values in the third through sixth cell.
The overview of these data indicate a high grade effluent.
These preliminary efforts are not seen as maximum efficiency, however
further research efforts should attain greater removals.
Food Habits
The preliminary data on food habits allowed general classifica-
tion of the fishes according to position in the food web. A dia-
gramatic representation is presented in Figure 5.
Tilapia nilotica, fathead minnows and golden shiners were
found to consume phytoplankton directly and microcrustacea and insect
larvae to a lesser extent. Channel catfish were found to utilize
microcrustacea and insect larvae as their principal foods.
This analysis was intended to provide preliminary information
regarding the food niche of each species. Future studies should
substantiate these preliminary conclusions on food habits.
Biomass
Since no supplemental feeding of fishes occured during the
experiment, it follows that fish biomass must have been elaborated
from organic constituents present in the system. It is then rea-
sonable to assume that all biomass gained during the observation
period represents entrapment of elemental constituents that would
possibly have been discharged to receiving waters if the fish had
not been present. Thus, the increase in fish biomass was viewed
with special interest.
Tilapia nilotica biomass increased from the initial 4 pounds,
consisting of 175 individuals (averaging three inches stocked in
July 1973) to 163 pounds in October 1973. The harvest consisted of
2339 fish with some individuals attaining lengths of ten inches. It
was felt that their planktivorous food habits, the presence of abun-
dant algae, and rapid reproduction rate were the major reasons for
this increase. The total biomass of Tilapia was not determined due
to procedural difficulties coupled with a sudden temperature drop
205
-------
NUTRIENT INPUT.
Nj
BIOLOGICAL
DECOMPOSITION
SLACK BULLHEAD
CHANNEL CATFISH
GREEN SUNFISH
BACTERIA
CHEMICAL
DECOMPOSITION
Figure 5 General Schematic Food Web of Organisms Inhabitins
Cell Three in the Quail Creek Lagoon System, 1973.
-------
which resulted in a large mortality. The biomass reported was deter-
mined from Tilapia removed. It is likely that a significantly greater
amount of Tilapia were produced and not recovered.
The biomass of channel catfish increased from the initial 600
pounds to an estimated 4400 pounds. However, the channel catfish
were observed to gain the majority of this biomass in a six week
period from late May 1973 to mid July 1973. Slow growth followed
this initial rapid gain. Reasons for this phenomenon are unclear
but limited information suggests stunting due to limited food supply.
After the virtual stoppage of growth, the system was not operating
at maximum efficiency for either water quality improvement or pro-
duction of fish biomass.
From the initial stocking of 85 pounds of golden shiner minnows,
only an estimated 535 pounds were recovered probably due to bullhead
catfish predation. It should be noted that only the production of
golden shiners in cells five and six was estimated. However, this
species was found in moderate numbers in other cells.
Further studies in this area should be oriented toward and
include detailed niche identification and utilization to maximize
production and resultant upgraded effluent quality by varied species
at varied stocking rates.
COST EVALUATION
The replacement of the physical-chemical technology with a
biological system producing a marketable product can help defer the
cost of treating sewage. Using this concept, cost-benefit analyses
were a part of the overall project. Cost figures for the project
are presented in Table 2. The cost of additional operation and
equipment (line 2) can reasonably be expected to decrease after
initial purchases of durable equipment are made. Total estimated
cost is 15C/1000 gallons of domestic sewage.
It is appropriate to note that this comparatively low figure
is for an effluent of high quality, surpassing secondary standards
usually attainable only through mechanical advanced waste treatment
technology. Costs of 40c to 45C/1000 gallons have been reported in
mechanical separation.6 If no monitary recovery at all were made
from the fish in tae system, this would remain an excellent effluent
at a comparatively low price.
The calculations in the lower body of the table project possible
cost recovery based on local market value. However, the production
estimates are based both on our data and literature sources which
suggest the average yield in fertilized systems.15
210
-------
TABLE 2
ESTIMATES OF PROJECTED COSTS & INCOME
FROM AN ADVANCED BIOLOGICAL TREATMENT SYSTEM
Costs
180 X 106 gallons/six months X .08C/1000 gallons = 14,400.00
Additional operational & equipment costs @ rate
of $20,000.00/year = 10,000.00
Fish 50,000 channels at 4c apiece = 2,000.00
50 gallons minnows at $15.00/gallon = 750.00
250 Tilapia at $1.00 each = 250.00
$27,400.7180 X 10& = 15c/l,000 gallons $ 27,400.00
Income
50,000 channel catfish at .250 each = 12,500.00
* 1,200 gallons minnows at $15.00/gallon = 18,000.00
* 18,000 pounds of Tilapia & bullheads at 6C/pound = 1,000.00
31.500./180 X 106 = 17
-------
Using these figures, a return of 2.3e/1000 gallons is possible.
However, even if these figures are high, any sale will be of benefit
to the community involved.
As the project proceeds, data will be obtained to more accurately
determine the benefits accured from such a biological system operating
toward maximum efficiency. The next phase of the project will be to
repeat the experiment with no fish present throughout the system.
272
-------
REFERENCES
1. Anon. Water Programs, Secondary Treatment Information.
U.S.E.P.A. Federal Register. 38^22298-22299, August 1973.
22. Cahill, H.P. Jr. Waste Stabilization Ponds. (Memorandum de-
fining secondary treatment standards) U.S. Environmental
Protection Agency. September 1973.
3. Anon. Fiscal Year-74 Water Pollution Control Program for
State of Oklahoma. Oklahoma Department Pollution Control.
(mimeo), 1974, 103p.
4. Anon. Permit Management Plan for Planning Basin One - State
of Oklahoma. Oklahoma Department Pollution Control, (mimeo),
1974.
5. Anon. Bacterial Reduction, Phosphate and Nitrogen Variations
and Algae Prevalence in Oklahoma Waste Oxidation Ponds.
Oklahoma State Department of Health. (No date).
6. Anon. Upgrading Lagoons. U.S. Environmental Protection Agency,
Technical Transaction Series, pp 43, 1973.
7. VanHeuvelen, W. and J.H. Svore. Sewage Treatment by the Lagoon
Method. Transactions Fourth Annual Conference Sanitary Engineer-
ing. Bull.#30:5-8, 1954.
8. Hopkins, G.J. and J.K. Neel. Sewage Lagoons in the Midwest.
Missouri Department of Health, Education and Welfare, pp 23,
1956.
9. French, D.E. Sewage Lagoons in the Midwest. Water and Sewage
Works, pp 537-540, December 1955.
10. Kincannon, D.F. The Role of Oxidation Ponds in Waste Treatment.
Journal Missouri Water and Sewage Conference 1966. pp 6-11.
11. Parker, D.S., J.B. Tyler and T.J. Dosh. Algae Removal. Wastes
and Wastewater Engineering, pp 26-29, January 1973.
12. Kothandaraman V. and R.L. Evans. Removal of Algae from Waste
Stabilization Pond Effluents—State of the Art. Illinois Water
Survey. Cir. 108:9, 1972.
213
-------
13. Trimberger, J. Production of Fathead Minnows (Pimepheles
promelas) in a Municipal Waste Water Stabilization System.
Michigan Department National Research, pp 4, 1972.
14. American Public Health Association. Standard Methods for the
Analysis of Water and Wastewater, 13 Edition. A.P.H.A. New York.
pp 873, 1971.
15. Altman, W.R. and W.H. Irwin. Minnow Farming in the Southwest.
Bulletin Oklahoma Department of Wildlife Conservation, pp 35,
(No date) .
274
-------
PART it AGRICULTURE
SESSION CHAIRMAN
RICHARD E. THOMAS
RESEARCH SOIL SCIENTIST
ROBERTS. KERR ENVIRONMENTAL RESEARCH LABORATORY
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA
-------
AN EXPERIMENT IN THE EUTROPHICATION OF TERRESTRIAL ECOSYSTEMS
WITH SEWAGE: EVIDENCE OF NITRIFICATION IN A
LATE SUCCESSIONAL FOREST
by
W "jV *fc
G. M. Woodwell , J. Ballard , J. Clinton ,
M. Small** and E. V. Pecan*
INTRODUCTION
Present practice in treatment of sewage is to release partially
treated effluents into water bodies and to rely on natural pro-
cesses for completion of the treatment. This system of disposal is
reaching clear limits as water supplies are exhausted and inland
and coastal waters become increasingly polluted. One alternative to
this "tertiary" treatment is to use natural or lightly managed
terrestrial and aquatic ecosystems singly or in combination as
living filters to remove nutrients and release potable water to
either ground or surface water channels. The system has the poten-
tial for enabling reuse of both water and nutrients.
A series of experiments has been designed at Brookhaven National
Laboratory to explore the potential of terrestrial and aquatic
systems for recovery of water and nutrients in effluents from primary
and secondary sewage treatment plants. Aquatic systems are a pond,
a freshwater marsh, a pond-marsh complex and two Phalaris arundinacea
meadows . The terrestrial research has been designed around the
field-to-forest sere of central Long Island1"3. The questions are
superficially simple: what is the potential for each of the major
communities of the sere for absorption of the solids and nutrient
elements in sewage and for the release of "clean" water? How can
terrestrial and aquatic systems be manipulated to offer the greatest
degree of treatment with the least commitment of fossil fuel energy
and the least management?
*Biology Department, Brookhaven National Laboratory, Upton, New
York 11973.
**Department of Applied Sciences, Brookhaven National Laboratory,
Upton, New York 11973.
***Research carried out at Brookhaven National Laboratory under
the auspices of the U. S. Atomic Energy Commission with partial
financial support from the Town of Brookhaven, Long Island, New
York.
275
-------
THE BROOKHAVEN PROGRAM
DESIGN
The design of the experiments was based on the assumption that the
hydrologic cycle for Long Island can be evaluated continuously if
precipitation and solar radiation are known^. Porous cup lysimeters
were used to sample the quality of the percolate that moves below
the rooting zone into the ground water; these data will ultimately
be used to appraise the water and nutrient budgets of the various
plant communities. We are reporting here on the design of the
terrestrial segment of the experiment and the early results, some of
which have been reported elsewhere^.
The experiments were established in a section of the Brookhaven
National Laboratory site called the Biology Farm (Fig. 1). The
terrain is flat throughout the area. Soils are thin, well-to-
excessively drained, coarse textured, and podzolic. They have been
derived from Wisconsin glacial outwash. Depth to the water table
ranges from 5-8 meters. The ground water flows southeastward at a
rate of about 13.4 cm/dayl.
Terrestrial plots included an agricultural field, and three commun-
ities that together span the field-to-forest sere of central Long
Island. The agricultural field was planted in the spring of 1973
with timothy (Phleum pratense). The sere was represented by old
field, pine forest, and oak-pine forest. The old field community
was abandoned after harrowing in the fall of 1972. Most of the
field had lain fallow for several years previously. The pine forest
was a naturally seeded stand of pitch pine (Pinus rigida) that was
about 25 years old in 1972. The late successional forest was
representative of oak-pine (Quercus alba. (}. coccinea, Jp. rigida)
stands on Long Island^"?.
Each of these plant communities was divided into three plots, a
control and two experimental. The agricultural control plot was
fertilized with 1680 kg/ha of commercial 5-10-10 fertilizer. No
other control plot received any treatment. The irrigated plots
received either primary or secondary sewage at the rate of about
5 cm/week supplementing the normal rainfall.
COMPOSITION OF SEWAGE
The sewage was a mixture of cesspool pumpings (scavenger wastes)
obtained from the Town of Brookhaven and sewage from Brookhaven
National Laboratory. Two blends were used; one to approximate
the effluent from a primary treatment plant; the second, from a
secondary treatment plant. A comparison of these blends with other
sewage appears in Tables 1 and 2.
276
-------
Table 1. Comparison of Brookhaven National Laboratory Primary Sewage Blend with Sewage from
Primary Treatment Plants in Various Locations.
Reference
MBAS
BOD
COD
S. Solids
D. Solids
Total Solids
NH3-N
NO.-N
NOo-N
ci-
Fe
Mn
P04
S04
K"*"
Na+
Ca2+
Mg2+
Cu
Zn
BNL
"Primary"
0.368
372
813
506
210
716
10.91
0
0.516
38.1
1.97
0.08
4.23
14.08
8.23
33.9
16.2
4.13
0.47
1.33
Muskegan
Mich.
(8)
17.21
0.89
92.0
0.99
0.15
3.04
22
9.63
65.6
85.05
0.93
1.18
Lancaster
Calif.
(9)
45
392
90
553
643
27
0
0.1
32
3
Allentown
Pa.
(10)
84
88
482
570
13.5
0.09
0.60
92
Port Jeff. Holbrook
N.Y. N.Y. x
(11) (11)
1.0
73 180
54 75
256 482
310 557
11.50
0.32
0
1.0
0.04
60
0 0.15
2.4
Selden
Domestic N.Y.
(12) (13)
130 240
120
560
680 228
15
-------
Table 2. Comparison of Brookhaven National Laboratory Secondary Sewage Blend with Sewage from
Secondary Treatment Plants in Various Locations.
BNL Muskegan Average
"Secondary" Mich, municipal
Reference
MBAS
BOD
COD
S. Solids
D. Solids
Total Solids
NH3-N
N02-N
NOo-N
ci-
Fe
Mn
po4
soj
Na+
Ca2+
Mg2*
Cu
Zn
0.512
131
280
168
172
340
5.29
0
0.931
33.9
1.08
0.03
1.93
10.59
5.27
28.46
12.35
3.37
0.24
0.70
(8)
27.4
0.12
122
0.73
0.04
3.32
29.6
12
80
129.6
0.08
0.11
(14)
6
25
730
15.5
0.3
3.5
130
8.3
33.3
15
135
60
25
Phoenix
Ariz.
(15)
15
45
24
0.2
213
13
35.7
8
200
82
36
Bay Park
N.Y.
(16)
0.77
69.9
5-20
384
34
0.045
0.06
101
0.22
0.03
6.2
165.3
11.2
0.02
Penn State
Pa.
(17)
0.54
12.8
5.1
4.44
0.10
13.8
52.8
32.0
16.3
Allentown
Pa.
(10)
35
54
489
543
1.23
0.47
5.12
93
Hoi brook
N.Y.
(11)
60
30
490
520
25.0
0.06
0
0.15
Hauppauge
N.Y.
(11)
20
1
399
400
3.0
0.3
0.5
-------
The two blends differed appreciably from one another and from other
sewage. Concentrations of phosphorus, sodium, potassium, calcium,
magnesium, chlorine, sulfate, and inorganic nitrogen (NH3, N02, N03)
were slightly lower than in other sewage. BOD and COD loadings were
high in both blends used in the Brookhaven work. Sediment content
was also high. The ratio of dissolved to suspended solids was very
much lower than in municipal effluents. Suspended sediments con-
tained approximately 6% nitrogen and 1% phosphorus. Of the dissolved
and suspended sediments, 40 and 807= were combustible and presumably
organic.
OPERATION
Two types of spray irrigation equipment were used. In the Primary
Agricultural Field sewage was applied by a rotating Aquatower con-
structed by MacDowell Corporation, DuBois, Pennsylvania. The tower
was designed to spray sewage under low pressure close to the surface
of the ground. The area covered was 4087 m^. This equipment has
the advantages that the land is not cluttered with piping and is
easily accessible to farm machinery, and the low pressure application
reduces aerosols. The tower has the disadvantage that it is complex
and easily disabled. Conventional aluminum irrigation pipe and
fittings were used in all other sprayed plots. Sprinklers were
standard Rainbird equipment.
The application rate was about 1 cm (40.4 m3/ha or 10,691 gal/acre)
per day; plots were sprayed Monday through Friday to apply about
5 cm (2 in.) per week. These operations required no more than
75 min/plot/day. Spray operations were conducted throughout the
year. In the first winter of operation difficulties encountered
during freezing weather prevented operation for several weeks, but
improved design will probably allow operation at temperatures well
below freezing.
The annual application rates for the chemical and sedimentary
constituents of sewage can be approximated from the following
relationship:
R = K S C
where R = the application rate in kg/ha/yr or Ib/acre/yr; K = a
constant (5.2 for kg/ha/yr and 4.6 for Ib/acre/yr); S = spray rate
in cm/week; C = concentration of the substance in question in
ing/liter.
Applications rates in the Brookhaven study for N, P and K were 2100,
240, and 215 kg/ha/yr for primary plots and 425, 95, and 140 kg/ha/yr
for*secondary plots. The total sediment deposit was approximately
3700 and 1750 kg/ha/yr for primary and secondary plots for the
spraying regime in use through 1973-74. Spraying was begun in the
pine forest and oak-pine forest on July 16, 1973 and in the old
field and timothy plots on October 2, 1973.
279
-------
SAMPLING
Sewage was sampled for chemical composition from the irrigation pipes
at the time of application. Amounts applied were measured with
buckets distributed in the treated plots1. Ground water was sampled
for data reported here using 16 wells that tap the upper segments of
the ground water1. Well pipes were plastic and slotted. A dye
study showed that the water moves through the wells with the flow of
the ground water.
Percolate was sampled with porous cup lysimeters placed in each plot.
A central vacuum system maintained about 1/10 atmosphere tension on
each lysimeter continuously. Difficulties with suction equipment
caused occasional increases in tension to as much as 6/10 atmosphere.
RESULTS AND DISCUSSION
GROUND WATER
The quality of the ground water varied greatly among the series of
ecosystems examined before spray irrigation was started. The most
important variation was in nitrate-nitrogen and calcium contents
(Fig 2). Although there was appreciable change in the nutrient
concentrations in the ground water through the year of sampling
before irrigation, the greatest differences were between the differ-
ent communities. The mean concentration of nitrate-nitrogen under
the forest was about 1/1000 that under the agricultural community;
the concentrations of nitrate-nitrogen under the intermediate
successional stands were intermediate. The data for calcium followed
a similar pattern (Fig. 2). The forest was clearly less of a source
of both calcium and nitrogen than the less mature communities.
Similar relationships were shown by other major nutrient elements,
although in lesser degree.
PERCOLATE
The data on percolation through the first six months of the experi-
ment corroborated the data from the wells. The forest appeared less
leaky for most elements than the successional communities. The
exceptionwu total nitrogen (Fig. 3), whose concentration in the
percolate of the primary plots after five months rose abruptly to
?he concentration in the spray. A similar Pattern was shown in the
plots treated with secondary effluent (Fig. 4), but the concen-
trations reached a maximum after three months and did not match
tJe concentration in the spray. Examination of the relationship
between the three forms of nitrogen (Fig. 5) shows that nitrogen
in^he percolate is in the nitrate form and that the total removed
in percolation is approximately the total nitrogen applied.
Apparently there is nitrification within the more mature forest
during the fall and winter. Whether the nitrification was triggered
220
-------
by the treatment remains to be seen. It did not occur in the pine
forest (Figs. 3,4) in either the primary or secondary treated plots.
This relationship simply emphasizes the complexity of the nitrogen
cycle and the need for greater emphasis on this type of study.
CONCLUSIONS
1. The quality of ground water on Long Island is affected profoundly
by the vegetation. The more mature, late successional forest pro-
duces percolation into the ground water that is normally low in the
major nutrients, especially nitrate-nitrogen. Agricultural commun-
ities and plant communities of early succession are leaky by
comparison.
2. The conversion of ammonium-ion nitrogen to nitrate appears
to occur in the irrigated stands of oak-pine forest during winter
but not in the pine stands. The question of whether irrigation has
triggered nitrification is unresolved.
3. There is little question that natural and agricultural commun-
ities can be used to treat sewage. There is need, however, to
examine how harvest of nutrients is to be accomplished most effect-
ively to avoid the accumulation of salts to the point where losses
equal inputs. The assumption seems justified that any treatment
system will require more than one plant community but there is little
basis at present for speculation as to the combinations that will
prove most useful.
227
-------
REFERENCES
1. Woodwell, G. M., J. Ballard, M. Small, E. V. Pecan, J. Clinton,
R. Wetzler, F. German and J. Hennessy. Experimental Eutrophica-
tion of Terrestrial and Aquatic Ecosystems. Technical Report,
Brookhaven National Laboratory, Upton, N. Y., in press.
2. Woodwell, G. M., B. R. Holt and E. Flaccus. Secondary succession:
structure and production in the field-to-forest sere at Brook-
haven, Long Island, N. Y. Ecology, submitted.
3. Ballard, J. and G. M. Woodwell. The flux of water and nutrients
to the ground water under a field-to-forest sere. In Proc.
IBP Grassland Biome Symp., Fort Collins, Colo., in press.
4. Woodwell, G. M. and A. L. Rebuck. Effects of chronic gamma
radiation on the structure and diversity of an oak-pine forest.
Ecol. Monogr. _37: 53-69, 1967.
5. Whittaker, R. H. and G. M. Woodwell. Structure, production, and
diversity of an oak-pine forest at Brookhaven, New York. J.
Ecol. 17: 157-174, 1969.
6. Harshberger, J. W. The Vegetation of the New Jersey Pine Barrens
An Ecologic Investigation. Christopher Sower Co., Philadelphia,
1916. (1970 Edition by Dover Poublications, New York).
7. Conard, H. S. The plant associations of central Long Island.
Amer. Midi. Nat. 16: 433-516, 1935.
8. Engineering Feasibility Demonstration Study for Muskegan County,
Michigan Wastewater Treatment-Irrigation System. Muskegan
County Board and Department of Public Works. Water Pollution
Control Research Series 11010FMY 10/70, 1970.
9. Dryden, F. D. and G. Stern. Renovated wastewater creates
recreational lake. Environ. Sci. Technol. JZ: 268-278, 1968.
10. Steel, E. W. Water Supply and Sewerage. New York, McGraw-Hill
Book Co., Inc., 1960.
11. Matzner, B. Chief, Operations Division, Suffolk County Depart-
ment of Environmental Control, personal communication, 1973.
12. Clark, J. W., W. Viessman and M. J. Hammer. Water Supply and
Pollution Control, 2nd ed. Scranton, International Textbook
Co., 1971.
13. Haack, C. Levitt Residential Communities, Lake Success, New
York, personal communication, 1974.
14. Weinberger, L. W., D. G. Stephan and F. M. Middleton.
Ann. N. Y. Acad. Sci. 136; 131-154, 1966.
15. Bouwer, H., et al. Renovating Secondary Sewage by Groundwater
Recharge with Infiltration Basins. EPA Water Pollution Control
Research Series, 16060DRV 3/72, 1972.
16. Environmental Protection Agency. Environmental Impact State-
ment on Wastewater Treatment Facilities Construction Grants for
Nassau and Suffolk Counties, New York, 1972.
17. Kardos, L. T. Unpublished results.
222
-------
FIGURE LEGENDS
Fig. 1. The Brookhaven National Laboratory site. The experiment
is at the Biology Farm in the southeastern corner of the site.
Sewage is prepared from scavenger wastes and untreated Laboratory
sewage and pumped to holding ponds at the experiment.
Fig. 2. Nitrate--N and Ca content of ground water under major plant
communities of the field-to-forest sere, Brookhaven, New York.
The ground water flows laterally at about 13 cm/day. Each curve
represents a single well.
Fig. 3. Total nitrogen concentrations in primary sewage and in
soil percolate under the plant communities of the sere.
Fig. 4. Total nitrogen concentrations in secondary sewage and in
soil percolate under the plant communities of the sere.
Fig. 5. Concentrations of ammonium-nitrogen, nitrate-nitrogen and
total nitrogen in primary sewage applied to terrestrial communities
and in percolate leaving the rooting zone. Key: S = sewage, P =
pine forest percolate, F = oak-pine forest percolate, A = agri-
cultural field percolate, 0 = old field percolate.
223
-------
;,
BROOKHAVEN NATIONAL LABORATORY
PHYSICAL FEATURES
FIGURE 1
-------
NITRRTE - N
CRLC1UM
.
:
-
.056
3.22
2.T6
2.30
.
0.00
BU MM 1C
«
z
a
ja ' *c ' *r ' a ' ** ' oil
Q
O
2.60
2.23
1.86
K
u 1.49
5 ••"
8 ...3
0.00
1972
1973
i.n
5.96
2.39
.
«r ' I, '
1972
1973
WELLS CONCENTRRTIONS
FIGURE 2
225
-------
o
LU
LJ
O
LJ
INPUT flND PERCOLflTE CONCENTRflTIONS
PRIMRRY PLOTS VEGETRTED
TOTflL N (SUM)
RUG
SEP
NOV
FIGURE 3
-------
INPUT nND PERCOLRTE CONCENTRATIONS
SECONDflRY PLOTS VEGETflTED
TOTflL N (SUM)
£
Kj
Nj O
CJ
O
LJ
HUG
SEP OCT
1973
Other
•'' plots
NOV
FIGURE 4
-------
RMMQNIUM - N
rF|FFPPfPB—B B| B B
_-
:
•
.
h
Z
—
0
-
7.60-
6.51-
5.43
4.34
3.26-
2.17
1.09
o.oo-
RUG
SEP
NITRRTE - N
OCT
NOV
SeWfC
RUG
SEP
TOTRL N (SUM)
•
BUG
SEP
OCT
1973
INPUT RND PERCOlflTE CONCENTRflTIONS
PRIMflRY PLOTS VEGETRTED
FIGURE 5
228
-------
IRRIGATION WITH WASTEWATER AT BAKERSFIELD, CALIFORNIA
by
Ronald W. Crites
INTRODUCTION
Wastewater has been used to irrigate cropland at Bakers-
field, which is located at the southern end of the San
Joaquin Valley in the central part of California, for more
than 60 years. The purpose of this paper is to document
the principal features of this successful operation by
tracing its historical development, current operation, and
environmental effects. Crop yields are related to the
characteristics of the effluent applied and compared to
typical yields in Kern County. Future plans are discussed
and the applicability of the data and experience gained
from this long-established operation to other similar
operations is delineated.
Normal annual precipitation in the Bakersfield area is
about 6 inches. Because it occurs mostly from December to
February, irrigation is necessary for summer crop produc-
tion. Since irrigation began in the area, agriculture has
been a major industry.
HISTORICAL DEVELOPMENT
Although the city has three wastewater treatment plants,
most of the domestic wastewater from the city is treated
at Plants No. 1 and No. 2, located southeast of the city.
The farmland adjacent to these two plants has received
wastewater since 1912, when the first portion of the
city's sewerage system was constructed.1 The outfall
sewers ended in an open ditch from which untreated waste-
water was taken for irrigation.
In 1933, the California Department of Health conducted a
state-wide survey of wastewater irrigation systems.2 The
report for Bakersfield was that 58 acres of cotton, 480
acres of wild grass, and an unspecified acreage of pasture
were being irrigated with untreated wastewater.
*Project Engineer, Metcalf & Eddy, Inc., Palo Alto,
California
223
-------
In 1939, a 9.0 mgd primary treatment plant (Plant No. 1)
was constructed. In 1952 the plant was severely damaged
by an earthquake and the effective capacity was reduced
to 4 mgd.$ In the same year, a 16 mgd primary plant
(Plant No. 2) was constructed approximately 2 miles to the
south. The city continued to dispose of the effluent from
both plants on adjacent farmland, now owned by the city
and leased to a grower. In 1948, a secondary treatment
plant was built adjacent to city Plant No. 1 by the Mount
Vernon Sanitation District, Although the effluent is
also used nearby to irrigate crops (pasture, alfalfa, and
barley), the Mount Vernon operation will not be discussed
further.
In 1956, Merz4 made a field visit and reported corn,
cotton, alfalfa, sorghum and grass being grown on 2,000
acres. In 1959, ScottS reported cotton, field corn,
milo maize, sugar beets, barley, and permanent pasture as
crops on the 2,500 acre farm. Finally in 1973, the crops
grown were cotton, corn, barley, alfalfa, and pasture
grass.6 Although the total farm acreage is 2,500 acres,
only about 2,400 acres can be irrigated for crop production,
CURRENT OPERATION
Presently the city of Bakersfield leases the farmland to
Mr. Joe Garone for $40,000.00 annually or $16.00 per acre.
Mr. Garone takes all the 13 mgd of effluent from the two
primary plants throughout the year. He rotates his crops,
maintains ditches, and controls the tailwater from
irrigation. The major summer crops are field corn and
cotton, with only 80 acres being planted to alfalfa. Mr.
Garone is in his fourth year as leasee; consequently, he
is still releveling certain areas and leaving some plots
fallow to reduce weed problems that he inherited.
Wastewater Characteristics
The wastewater is primarily domestic in nature, with only
a few poultry-processing plants discharging high-BOD
wastes to Plant No. 1. The characteristics of effluents
from Plant No. 1 (3.5 mgd) and Plant No. 2 (9.5 mgd) have
been combined and a typical blend of constituents that
would be found in the irrigation water is given in Table 1.
The domestic water supply for Bakersfield is obtained from
deep groundwater wells. Nitrate concentrations up to 18
and 19 mg/1 as nitrate are found in some of these wells.
230
-------
Table 1. Characteristics of Treated Effluent
at Bakersfield
Values in mg/1
Characteristic except as noted
Flow, mgd 13.0
BOD 150
Suspended solids 48
Total nitrogen as N 28
Ammonia nitrogen as N 25
Organic nitrogen as N 3
Nitrate nitrogen as N 0
Phosphorus as P 6.2
pH, units 7.2
Total dissolved solids 380
Chloride 60
Sulfate 90
Bicarbonate 220
Calcium 15
Magnesium 18
Sodium 112
Potassium 12
Percent sodium 65
Sodium adsorption ratio 4.4
Boron 0.5
The mineral quality of the combined primary effluent is
quite suitable for irrigation. The total nitrogen level
of 28 mg/1 causes some problems in the growing of cotton,
as will be discussed later. The.percent of sodium is
relatively high at 65 percent; however, it is not critical
The total dissolved solids (TDS) concentration is not a
problem for any of the crops grown.
Site Characteristics
The topography is very flat, with the fields graded for
surface irrigation. General drainage is from north to
south with sump pumps along the southern end to return
tailwater to storage ponds (See Figure 1). Soils range
from fine sandy loams to clay loam. The soils are
237
-------
WELL NO.2
PLANT NO. 1
•RESERVOIR
• CLL
Nt.5
fILL
M.4-
BARN
PLANT NO.2
m
\
WELL
NO. 3
-
RESERVOIR
[STORAGE
POND
PASTURE
SOUPS
SUMP-
FIGURE 1 SOUTHEAST BAKERSFIELD CITY FARM
232
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generally alkaline and poorly drained with dense clay
lenses at depths ranging from 10 to 15 feet below the
surface. This clay barrier produces perched water in
areas where it is continuous and reduced percolation in
areas where it is not.
Permanent groundwater aquifers exist at approximate depths
of 100 to 200 feet and at 300 feet. The two are separated
by a clay barrier, and the confined lower aquifer is used
for water supply. The deep wells on the farm, as shown in
Figure 1, produce water for supplemental irrigation water.
The quality, however, is inadequate for potable uses as a
result of high TDS and nitrate content.
Crop Irrigation
All crops are irrigated by surface methods. Corn and
cotton are irrigated using the ridge and furrow method;
and pasture, barley, and alfalfa using the border strip
method.
The nitrogen needs of the crops, the usual amounts added
by commercial fertilizer in Kern County, and the actual
nitrogen loading rates are given in Table 2. -As can be
seen, the nitrogen applied more than meets the nitrogen
uptake of all crops. For both cotton and alfalfa,
nitrogen loading is more than
utilized.
fertilized
fertilizer
expense of
descreased.
Table 2.
the
twice that which can be
Because alfalfa is a legume, it is not usually
with nitrogen. For cotton, excess nitrogen
results in excess vegetative growth at the
fruitive growth, and subsequent yields are
Nitrogen Loadings at Bakersfield Compared to
Typical Fertilizer and Uptake Rates
Crop
Alfalfa
Barley
Corn
Cotton
Pasture grass
Actual
Nitrogen
loading
rate from
effluent,
Ib/acre/yr
371
139
252
277
371
Typical
commercial
fertilizer
rate,
Ib/aere/yr
_.b
80-90
200-250
100
100+
Nitrogen uptake,
Ib/acre/yr
100-150
75
150
100
150-250
a. Average for Kern County.
b. 50 Ib/acre/yr of P70r added by some growers.
233
-------
Liquid loading rates and loadings of BOD, potassium, and
phosphorus are listed in Table 3. The irrigation and
agricultural practices will be discussed individually for
each crop.
Table 3. Loading Rates for Primary
Effluent at Bakersfield
Crop
Alfalfa
Barley
Corn
Cotton
Pasture grass
Liquid
loading
rate,
ft/yr
4.9
1.8
3.3
3.7
4.9
BOD
loading
rate ,
Ib/acre/yr
1,985
730
1,500
1,500
1.98S
Potassium
loading
rate,
Ib/acre/yr
159
58
107
120
1S9
Phosphorus
loading
rate,
Ib/acre/yr
82
30
55
62
82
Alfalfa - Alfalfa is a perennial crop that is irrigated
from March to October at about 2-week intervals. Cuttings
are made approximately monthly during this period. As
noted in Table 2, some growers in Kern County fertilize
with 50 pounds of P20s per acre, which is equivalent to
about 11 pounds of elemental phosphorus.
Alfalfa will take up to 21 pounds annually of phosphorus
and 110 pounds of potassium.7 Both uptakes are more than
met by the application of effluent.
Barley - Planted in mid-December, barley can be harvested
for grain in mid-May or early June, or it can be grazed.
Mr. Garone allows his cattle to graze about 160 acres of
barley in rotation with other pastureland and the feed lot
Barley is pre-irrigated in November, and then irrigated
once every 2 weeks from mid-March to harvesting. Barley
that is grazed is generally disced under by June 1 to
allow the field to be prepared for planting of corn.
Corn - Planted in early June or late May, corn requires a
great deal of water during its 90 to 100 days of growth.
Corn is generally irrigated at a rate of nearly 3 in./wk.
Mr. Garone harvests his field corn in September for
ensilage and hauls it to his feed lot.
Cotton - Cotton is an annual crop, planted in mid-March
and harvested in mid-October. Land to be planted is
pre-irrigated with about 15 inches of effluent in
February. Irrigation of the cotton begins in June and is
23ft
-------
ceased by September 1. Mr. Garone has problems growing
cotton because irrigation with 3.7 feet of effluent adds
nearly 3 times as much nitrogen as needed. This ?esultl
in excessive plant growth and reduced yields To com
?oenme(hinr?hUl mana*ement is ^quired, including steps
to (I) thin the cotton more than usual, (2) stress the
plants between irrigation periods to stimulate fruitive
growth and (3) blend effluent with well wa?e? to deduce
the total nitrogen concentration. Despite the use of
less%h™ ?iqUCSf ^°tt0!? ylelds are g^erally 20 -percent
less than the county-wide average.
Pasture - Mr- Garone raises pasture grass on the remaining
portions of the farm. These 750 to loo ac?es represent g
the poorest soils and also receive the tailwater from
other areas. Pumps and small sumps exist at the south
51 5 ° ^ Pastureland to return tailwater to a storage
pond. The pastureland supports between 1.5 and 2 animal
units per acre. The land is irrigated every 10 to 14 days
throughout the year In the past, excessive irrigation has
led to ponding in the southern portion of the pastureland,
with problems from odors and mosquito propagation resulting
Crop Yields
Yields resulting from irrigation with primary effluent
typical prices commanded by each crop in 1973 and the'
economic return per acre are presented in Table 4 The
double-cropping practice of barley followed by field corn
will yield the highest gross economic return but will also
require the most field preparation, cultivation and
management.
Table 4. Crop Yields and Economic Return
Crop
Alfalfa
Barley
Corn
Cotton
Yield,
Ib/acre
16,000
3,000-5,000
36,000-60,000
600-800
Typical
price ,
$ per pound3
0.025
0.045
0.0075
0.35
Economic return,
$ per acre
400
135-225
270-450
210-280
a. Based on 1973 prices.
235
-------
Alfalfa yield is equal to, if not slightly higher than, the
county-wide average of 6 to 8 tons per acre. Barley yield
is also approximately the same as the county-wide average.
Corn yields on a county-wide basis are 20 tons per acre.
Mr. GaroneS finds that up to 30 tons per acre are possible
on the heavier loam soils, while 18 tons per acre is a
typical yield on the sandy alkali loam soil.
Yields for cotton are typically 20 percent less than
county-wide averages as a result of the excess nitrogen
and the compensatory measures required, and because of
the relatively poor quality alkali soil. To increase
yields, Mr. Garone is applying gypsum to areas that are
strongly alkaline. When Merz visited in 1956, he reported
that gypsum was applied at 4 tons per acre.4 He also
reported a cotton yield of 1.82 bales per acre for 1955
compared to the current yield of approximately 1.5 bales
per acre.
E c o n om i c C o n s i d e r a t i o n s
Although the original cost of the land was probably less
than $100.00 per acre because of the poor quality of the
soil, it is now worth close to $1,000.00 per acre. Mr.
Garone?s lease from the city amounts to about 20 percent
of the operation and maintenance costs for the two treat-
ment plants, which are approximately 5 cents per thousand
gallons.7 Thus the city's property has appreciated in
value, while 20 percent of their annual budget for two of
their plants is repayed from the farming operation.
The cost of irrigation water from the local canal is
about $5.00 per acre-foot at the canal side, and the
cost of pumping groundwater is typically $15.00 to $20.00
per acre-foot. If the $40,000 lease applied only to the
14,500 acre-feet of effluent supplied, the cost of
effluent would be $2.76 per acre-foot. This economical
price must be balanced against the requirement of managing
excess flows in the winter.
HEALTH EFFECTS
Merz4 reported that no diseases have been traced to
effluent use, although there have been problems with flies
and mosquitoes. The current Superintendent of the city's
treatment plants, Mr. James Groves,9 reiterated that no
diseases have been associated with the operation.
Mosquitoes are a problem wherever water is allowed to pond
and stagnate, so that keeping the excess water moving is a
major management problem. The two equalizing reservoirs
236
-------
(5 and 10 acres in size) and the storage pond for tail-
water are periodically sprayed to control mosquito
propagation.
Current public health regulations for irrigation of fodder,
fiber, and seed crops are that the quality of reclaimed
water shall be equivalent to primary effluent.10 No
disinfection of the effluent is required, and none is
provided at the two plants. Dairy cows are not allowed
to graze pastures irrigated with nondisinfected effluent;
however, beef cattle are not restricted.
ENVIRONMENTAL EFFECTS
A complaint by the Regional Water Quality Control Board
that the irrigation operation was contaminating the
groundwater with nitrates led to an investigation of the
groundwater quality by Metcalf $ Eddy.° Six shallow wells
were drilled and sampled in late 1972. Perched water was
found at the 11- to 12-foot depth in 3 wells and not at
all in the other 3 wells (drilled 30 feet deep) . Nitrate
concentrations ranged from 4 mg/1 as nitrate in the center
of the farm to more than 600 mg/1 nitrate directly beneath
the old site of the sludge drying beds at the Mount Vernon
plant.
The Regional Board conducted a sampling program in
September 1971 and found nitrate concentrations ranging
from 0.4 mg/1 to 68 mg/1 as nitrate. These wells were
along the western edge of the farm, which is in the
direction of flow of the unconfined aquifer. These wells
were sampled at depths of 80 to 170 feet.
No firm conclusions relating effluent irrigation to
groundwater nitrate levels could be drawn from either
investigation. The confined aquifer below the farm
(300 feet deep) has nitrate concentrations of 50 to
60 mg/1 as nitrate.6 However, many wells, both deep and
shallow throughout the Balcersfield area have high nitrate
and TDS concentrations. The graundwater hydrology of the
area is complex and groundwater quality is influenced not
only by irrigation practices, but also by oilfield well
injections, natural occurrences of salt, and cattle feed-
lots. A more detailed investigation of groundwater
quality is in the planning stage for 1975.
FUTURE PLANS
Because of the problems with mosquitoes, the ponding of
excess irrigation water in the winter, and the poor
237
-------
quality of effluent from Plant No. 1, the state has
required that the city investigate alternative treatment
and reuse systems. Metcalf § Eddy conducted this investi-
gation and prepared a project report.3 Treatment and reuse
alternatives included (1) overland flow treatment and dis-
infection with effluent discharge to an irrigation canal,
(2) treatment and continued irrigation using more land,
(3) treatment and reuse in recreational lakes, (4) treat-
ment and groundwater recharge followed by withdrawal for
discharge to irrigation canals, and (5) advanced waste-
water treatment with discharge to the irrigation canal.
It should be noted that for Alternative 2 the Regional
Water Quality Control Board proposed a requirement of
secondary treatment prior to irrigation, which is more
restrictive than the State Department of Health regulations
require. Although all alternatives would involve benefi-
cial reuse, Alternative 1 was the most cost-effective.
Current plans (provided the regulatory agencies approve
the concept) are to consolidate Plant No. 1 and No. 2 and
construct a pilot overland flow (spray-runoff) system.
The design of this first stage could begin as early as
July 1974.
SUMMARY
Much can be gained by studying the successful operation of
wastewater irrigation at Bakersfield. Storage of effluent,
control of tailwater, and circulation of water to avoid
shallow ponding are successful management techniques that
have been developed. Control of the farming operation by
an experienced grower who applies proper amounts of water
for crop needs, adds soil amendments as needed, and com-
pensates for excess nitrogen (in the case of cotton) is
another lesson.
Crop yields vary from slightly below to well above the
county-wide average. These yields are greatly affected
by the soil characteristics as well as the effluent
characteristics. The alkaline soil is still being
reclaimed by additions of gypsum in certain areas.
ACKNOWLEDGEMENTS
The cooperation of Mr. Joe Garone and Plant Superintendent
Mr. James Groves is gratefully acknowledged. The typical
county-wide yields and prices were provided by Mr. Dave
West of the Agricultural Extension Service in Bakersfield.
238
-------
REFERENCES
1. Stevens, R.M. Green Land--Clean Streams: The
Beneficial Use of Waste Water through Land Treatment.
Center for the Study of Federalism, Temple University.
Philadelphia, Pennsylvania. 1972.
2. Files of the Bureau of Sanitary Engineering, California
Department of Health. Berkeley, California.
3. Metcalf § Eddy, Inc. Project Report for the Bakers-
field Sub-Regional Wastewater Management Plan. Pre-
pared for the City of Bakersfield and Mount Vernon
County Sanitation District. February 1974.
4. Merz, R.C. Continued Study of Waste Water Reclamation
and Utilization. State Water Pollution Control Board
Publication No. 15. Sacramento, California. 1956.
5. Scott, T. M. Effluent Grows Crops on "Sewer Farm".
Wastes Engineering, 3£:486-489, 1959.
6. Metcalf § Eddy, Inc. Preliminary Investigation of
Wastewater Treatment and Disposal for Southeast
Bakersfield. Prepared for the City of Bakersfield
and Mount Vernon County Sanitation District.
January 1973.
7. Pound, C.E. and R.W. Crites. Wastewater Treatment and
Reuse by Land Application, Volumes I and II. Office
of Research and Development, Environmental Protection
Agency. August 1973.
8. Garone, J. Personal Communication. February 1974.
9. Groves, J. Personal Communication. February 1974.
10. California State Department of Health, Water Sanitation
Section. Statewide Reclamation Criteria for Use of
Reclaimed water for Irrigation and Recreational
Impoundments. February 1974.
239
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NUTRITIVE VALUE OF AEROBICALLY TREATED
LIVESTOCK AND MUNICIPAL WASTES *
by
D. L. Day and B. G. Harmon **
Numerous methods of utilizing livestock wastes (manure) have been
studied, including spreading it on the land as a fertilizer; using it
to produce fuels, make building materials; composting it for a soil
annnendment; and various methods of processing for refeeding. Using
livestock wastes to produce feedstuffs offers two obvious advantages:
minimizing environmental pollutants and realizing a new source of
nutrients.
The acceptance of procedures that utilize treated wastes as nutrients
requires some explanation and education. However, refeeding animal
excrement, either inadvertently or intentionally, has been practiced
to some extent since the domestication of animals.
Before vitamins and amino acids were understood, livestock producers
knew that the fastest-growing and most-efficient hogs were those that
"followed" the cattle. The hogs gleaned the cattle manure for un-
digested grain, but they also utilized the vitamins and monocellular
protein. Also, young pigs needed more iron than they received from
sow's milk. Access to the sow's feces containing high levels of
biologically available iron prevented anemia in the pigs. Modern
livestock rations are nutritionally balanced to avoid such problems;
however, processed wastes can supply some of the nutrients and thus
help resolve the waste-management problem.
This paper deals with the aerobic treatment of metabolic wastes for
utilization in diets of livestock as a source of various nutrients but
especially protein as amino acids. Aerobic treatment of sewage is a.
long-known process by which microbial activity is intensified (Arden
and Lockett, 1914). By its nature, this is a low-odor process; but it
requires external power for the aeration. In recent years, the aerobic
*Paper prepared for presentation at the conference on Use of Waste-
water in the Production of Food and Fiber, March 6-8, 1974 Oklahoma
City, Okla.
**Departments of Agricultural Engineering and Animal Science,
University of Illinois at Urbana-Champaign.
***This project is presently supported in large part by the Illinois
Agricultural Experiment Station.
240
-------
treatment of livestock wastes has gained popularity mainly because of
its low-odor characteristic (Jones et^ al., 1971). The power require-
ment for continuous aeration is the main disadvantage.
NUTRIENTS IN MUNICIPAL ACTIVATED SLUDGE
Hurwitz (1957) reported the amino-acid, vitamin, and mineral content of
dried activated sludge from the Metropolitan Sanitary District of
Greater Chicago, Table 1. This product was successfully used as a feed
additive for swine, poultry, and sheep and beef cattle in experiments
at the University of Illinois in the 1950's (Schendel and Johnson,
1954; Firth and Johnson, 1955; and Hackler et_ al., 1957). These studies
established the value of vitamin B-_, nitrogen, and unidentified growth
factors in the activated sludge. There were, however, some severe
diarrhea problems with steers and lambs (Hackler, 1958).
Work conducted at Bangalore, India in the 1960's showed that half of
the vegetable and animal protein supplements in the diet for chicks can
be supplied by activated sludge (Pillai et^ al., 1967). Table 2 shows
an analysis of the sludge. The experiment was carried through the egg-
laying period, and significantly more eggs were laid by the birds on
the sludge-supplemented diet than by those being fed a typical diet.
Pillai et al. (1952) also reported that the purification processes
inherent in the aerobically treated activated sludge eliminated patho-
genic bacteria causing typhoid, cholera, and dysentery.
A method of producing organic molasses by the hydrolysis of activated
sewage sludge is reported by Bouthilet and Dean (1970). The molasses
had an amino-acid content favorable for animal feeds, Table 3; and it
was successfully fed to weanling rats at the 5- and 10-percent level;
feeding at the 25-percent level produced detrimental results.
An analysis of grab samples of activated sludge from the Urbana,
Illinois Municipal Waste-Treatment Plant is given in Table A.
NUTRIENTS IN AEROBICALLY TREATED LIVESTOCK WASTES,
UNIVERSITY OF ILLINOIS PROJECTS
Since 1963, a research project has been underway at the University of
Illinois at Urbana-Champaign on managing livestock wastes by means of
aerobic treatment in oxidation ditches beneath slotted floors in live-
stock buildings, a modified form of the Pasveer oxidation ditch (see
Figure 1). The original emphasis was on odor control and low-labor
waste management; but in recent years, the microbially enhanced
oxidation ditch mixed liquor (ODML) has been studied as a source of
nutrients for livestock.
An analysis of a sample of swine ODML in 1967 showed a high potential
for a protein supplement, Table 5. The refeeding implications are
obvious. Methods of isolating and concentrating the amino acids were
247
-------
Table 1. Amino Acid and Vitamin Content
of Activated Sludge (Hurwitz, 1957)
Amino Acids, per cent (dry basis)
Total Protein
(N x 6.25)...
30-35 per cent
Arginine 1.04-1.26
Cystine 0.18
Histidine 0.41-0.50
Jsoleusine 0.91-2.20
Ltusine 1.58-2.03
Lysine - 0.92-1.33
Methionine 0.45-0.65
Phenylanine 1.20-2.00
Threonine ._ 1.15-2.20
Tryptophane 0.22-0.34
Valine 1.1&-2.77
Tyrosine 0.70
Glyciue _ 1.55-1.71
Gluta»ic acid ....„ _ 2.89
Vitamins M gm/gm (dry basis)
pgm/gm
Riboflavin (Bs) ..„ 12.7-29.0
Cobalamine (Bu) 2.4- 4.0
Pantothenic acid 4.0-
Niacine _ 76.4
Coline 212.
•Pyridorine 1.2
*Biotin C.7
*Inositol 6401
•Kibi. Vitamin 10,433
Ions and Metals
Common ions
Trace Metals
(Spectrometric Analysis)
Aluminum 3
Calcium 2 -3
Iron 5 -6
Magnesium 0.5-1
Silicon 5 -6
Sulfate (SO,) 1
Phosphate (F.-Oj) 5 -6
per cent (dry basis)
-4percent Boron 0.002 per cent
Chromium 0.1
Copper 0.1
Lead 0.1
Manganese 0.1
Xickel 0.1
Potassium 0.1
Silver 0.1
Tin 0.1
Titanium 0.1
Zinc 0.1
Cobalt 8-1 n
ppm
24(2
-------
Table 2. Analysis of Municipal Activated Sludge
(Pillai et al., 1967)
(The results, except vitamin Bt2, are expressed as parcenir-oe on
ovea dry basis}.
Organic matter (loss en ignition) $7.5
Nitrogen (M) 6 C
Crude protein 37.5
Fatty matter (Petroleum ether extractable) C.O
Crude fibre g S
Minsral matter (residue on ignition) 32.3
Silica (S:O.) g'g
Calcium (C=) 1.54
Phospliorus (P) :^9
Vitamin B|2:
Total activity ;tg,'1CO g 75.8
Truo activity (alkali labils) /ig/100 g 73.5
Table 3. Amino Acid Analysis of Organic
Molasses (Bouthilet and Dean, 1970)
Amino Acid Percent dry basis
Arginine 0.79
Cystine 0.17
Clycine l.gg
Histidine 0.37
Isoleucine 1, gg
Leucine 1.01
Lysine 0.87
Methionlne 0.36
Phenylalanine 0174
Threonlne 1.13
Valine !.37
Crude protein 20
(Nx6.25)
243
-------
Table 4. Amino Acid and Mineral Content of
Activated Sludge From Urbana Waste Treatment Plant
Amino Acids *
Arginlne
Hlstldlo*
iBoleukimt
LMuslae
lymia*
MBthioaiM
Threo&lxM
Percent
dry matter
1.20
0.56
0.93
1.89
1.37
0.48
1.35
Minerals b
Art
Calcium
Iron
K*gn*«iuB
Phoiphoru*
Percent
dry matter
32.12
3.36
0.80
1.32
3.24
•. Average of two grab •••pin. 1971.
b. Grab MBpl«, 1974.
reported by Holmes e_t^ al_., (1971). These studies verified that the
major portion of protein was in the very small-sized particles and
could be passes through a 200-mesh sieve (74 micron openings),
supporting the theory that it is monocellular protein produced by
microbial enhancement, Table 5. Screening was not a practical method
of concentrating the high proteinaceous fraction of ODML, but the size-
analysis studies were of interest because they showed a definite
relation between particle size and protein content-the smaller the size,
the higher the protein.
Other methods of concentrating the proteinaceous fraction were also
tested, including settling and centrifugation. Using a centrifuge was
the most effective method. An amino-acid analysis of swine ODML
centrifuge cake is given in Table 6. The protein concentration varied
with the depth into the centrifuge cake, the farther into the cake,
the more the G force, and the less the amino-acid content. Clarified
ODML centrate was also analyzed for its amino-acid content, but none
was detected.
Most of the nutrition attention has been given to amino-acid content,
partly because amino acids are the most obvious constituent of the
single cells and partly because they are the costliest of the nutrients
needed to supplement corn. Lysine is one of the most used indicators
of amino acid quality because of the low lysine in corn. ODML also
contains vitamins and minerals, but these have less economic value
than the amino acids at the present time.
The nutritional value of swine ODML was first tested by including a
dried product in the diets of growing rats to provide the protein of up
to half the soybean meal. Satisfactory gains and efficiency values
244
-------
ROTORS
/
/
J
•N
w — - 1-' >-
p—
PLAN VIEW OF AN OXIDATION DITCH
ELEVATION VIEW
Figure 1 Totally Slotted Swine-Confinement Building With
an Oxidation Ditch Beneath the Self-Cleaning Slotted Floors
resulted (Harmon e^t _al. , 1972). Next, finishing swine were used in
trials where several ODML refeeding schemes were tested (Day and
Harmon, 1972). Two of the simpler schemes are depicted in Figures 2
and 3.
As shown in Figure 2, ODML was pumped from the oxidation ditch into a
holding tank where it was further aerated between feedings in order to
avoid the possibility of refeeding any unprocessed wastes. To verify
the nutritional value, ODML from the holding tank or water was mixed
with a 12-percent protein diet in a ratio of two parts liquid to one
part feed (approximately the normal ratio of water to feed that finish-
ing swine consume). Regular waterers were provided in all pens.
Nutrient composition of the ODML for one experiment is given in Table
7. Corresponding oxidation ditch operating parameters are given in
Table 8. In five replications, a total of 76 finishing hogs were fed
twice daily in open troughs. The gain and efficiency values were
significantly greater for hogs receiving the ODML, Table 9.
245
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Table 5. Amino Acid Contents of Aerobically Treated
Livestock Wastes Compared to Corn, Soybean Meal,
Swine Feces, and Pig Requirements
(Percent dry matter)
Arglnlne
Cystioe
Clycioe
Ri at Id In*
Isoleuslne
Leusine
Lysine
Methlonlne
Phenylalaalae
Threonine
Trypotophao
Tyrodne
Vallne
Aapartlc acid
Clutanic acid
Crude protein
(N«6.25)
a,b Crab i ample
c Avg. of two
d Crab sample
e Fresh swine
Beef
ODML*
1.85
0.56
1.49
1.03
1.19
2.28
1.68
0.62
1.34
1.35
0.96
1.72
2.75
3.79
Poultry
ODML t>
1.43
0.43
1.69
0.80
1.40
2.48
1.76
0.69
1.34
1.54
—_
1.15
2.11
3.15
3.61
Swine
ODMLC
3.49
0.51
3.70
1.39
2.96
4.53
3.46
1.38
3.58
3.13
1.96
3.30
5.35
9.56
Swine.
OWL d
1
1
2
0
1
2
1
1
1
1
1
2
3
5
.73
.30
.15
.45
.66
.91
.64
.41
.62
.86
.36
.26
.82
.37
Swine
Feces6
0.44
—
0.14
0.52
0.92
0.60
___
O.S1
0.53
—
0.58
—
45.6
t passed
grab sea
. 1967.
through a 200
•ash sei
pies passed through a
•een,
200
1971.
mesh act
•en, 1971.
Pig f
Req't.
0.28
0.24
0.27
0.74
0.79
0.53
0.58
0.49
0.13
0.50
—
16
Corn*
0.
0.
0.
0.
1.
0.
0.
0.
0.
0.
0.
0.
0.
1.
a.
46
12
22
31
04
26
18
42
34
058
36
45
61
61
69
Soybean
Mealh
3
0
1
2
3
2
0
2
1
0
1
2
5
7
45
.09
.42
.00
.21
.69
.69
.63
.39
.93
.69
.73
.36
.82
.74
.7
faces (Covens, 1966).
f Weenling pig (Becker
et at., 1966)
g.h (HarmoD et al., 1969).
Table 6. Amino Acid Analysis of Swine ODML
Screened and Centrifuged (Holmes, 1971)
(Percent dry Batter)
Centrifuge Cake
(Composite)
Arglnlne
Cyatine
Clycine
Hifttldine
Isoleuslne
Leusine
Lyslne
Hethionine
Phenylal anise
Tbreonine
Tyro sine
Valine
Aspartic Acid
Glutamic Acid
1.15
0.41
2.07
1.00
1.24
2.16
1.78
0.54
1.26
1.71
1.15
2.14
3.17
2.90
Varying Radial '
Distance Into Cake
2.52 1.15
1.70 0.77
2.85 1.70
Contained on
20 Mesh Screen
0.566
0.177
0.432
a. Sharpes Mark III Centrifuge
-------
ODML HOLDING TANK
( MIXED AND AERATED)
FEEDER
WflTERER
OXIDATION DITCH ~
-PUMP
Figure 2 ODML is pumped from the oxidation ditch into a holding
tank where it is kept mixed and aerated between feedings to pre-
vent the possibility of feeding any unprocessed wastes. The ODML
is fed by adding it to a regular ration in the ratio of 2 parts
ODML to 1 part dry diet. Regular water is provided. (Day and
Harmon, 1972).
FEEDER
VWTERER
PUW
OXIDATION DITCH -^ „-
Figure 3 ODML is pumped from the oxidation ditch directly into
a watering trough. No other water is provided. (Day and Harmon
1972).
247
-------
Table 7. Nutrient Content of Swine ODML April-August, 1971
[The oxidation ditch had been in operation
since spring, 1969, without emptying.]
Phenylalanine
Lysine
Histidine
Arginine
Threonine
Valine
Nethionine
Isoleucine
Leucine
Aspartic
Serine
Glut ami c
Pro line
Clycine
Alanine
Tyros ing
Tryptophan
g Means of 13 weekly
Men of 6 weekly
Percent .
dry matter-'
1.48
1.42
.47
1.28
1.96
2.06
.77
1.49
2.79
J.73
2.5S
S.06
1.29
2.29
2.83
1.17
0.28
analyses of ami no acids
analyses of minerals.
Calcium
Phosphorus
Magnesium
Sodium
Potassium
Iron
Copper
Zinc
except for tryptophan
Percent b .
dry matter—
3.33
3.83
1.49
2.75
4.14
.5507
.0071
.1148
(1 analysis).
Table 8. Summary of Weekly Samples, April-August, 1971
[The oxidation ditch had been in operation
since spring, 1969, without emptying.]
Parameter
pH
Dissolved oxygen, Mg./l.
Temperature. *C
Cheaical oxygen coma-nd, mg./l.
Dry matter, pet.
Nitrcgen, pet. dry matter
Ash, pet. dry matter
Mean
7.7
1.3
27
29,423
3.4
7.9
41.7
Range
6.0 -
0.3 -
17.5 -
18,425 -
2.1 -
S.I -
36.1 -
8.0
4.3
37.0
55,300
4.0
10.0
48.7
248
-------
Table 9. Performance of 76 Finishing Swine Fed
ODML or Water Mixed with Feed (Harmon et al., 1973A)
Wateri/
Average daily gain
Replication
1 1.08
2 1.01
3 1.08
4 1,41
5 1.10
Average 1.14
Gain p.?r 1,CC./ pf>;,/.i: „•_" feed
P.epl ication
pounds
Source: Harmon et al., 1973.
£/ Initial weight, approximately 110 pounds.
t/ Liquid added to feed, 2:1 ratio.
1
2
3 .
4
5 . . . . .
Average
.... 218
213
275
283
256
249
232
249
276
302
270
266
Table 10. Performance of 120 Finishing Swine Receiving
ODML or Water (Harmon et_ al. , 1973)
Dallv aain
Tap H?0
Replication
1 1.34
2
3
4
5
6
Av
1.45
1.69
1-32
1.28
- . 1-56
;rage 1.45
Source: Harmon et al., 1973.
ODMl
1.39
1.54
1.98
1.58
1.45
1.74
1.61
Each
Gain oer 1.000
Tap H20
pounds
303
296
244
230
260
309
-Z7JT
value represents 10 pigs
pounds of feed
ODML
308
297
343
278
263
338
~~30~4~
249
-------
Hogs slaughtered from each replication showed no evidence of liver or
lymphatic alteration due to feeding the single-cell protein source
(Harmon je£ al. , 1973A) .
As shown in Figure 3, ODML was pumped directly from the oxidation ditch
into troughs for 20 seconds out of every 10 minutes. The initial flow
flushed out the remaining liquid in the trough, while the flow as the
pump stopped remained in the trough. This provided fresh ODML at all
times. No other waterers were in the pens. Control swine had access
to regular water at all times. A corn-soybean meal diet (12-percent
protein) was available in self-feeders in each pen. For three experi-
ments (two replications per experiment) with 120 finishing hogs, the
weight-gain and feed-efficiency values were greater for the hogs re-
ceiving the ODML, Table 10. (Harmon et^ al., 1973).
The scheme of Figure 3 uses the processed waste in situ to furnish
water requirements as well as other nutrients. With this scheme, there
is little if any surplus material for disposal. The levels of non-
biodegradable materials will build up, and eventually have to be re-
moved .
A brief energetic and economic analysis of the operation depicted in
Figure 3 is given in Table 11. The energetics show a slight loss and
the economics show a considerable gain based on the current price of
soybean meal. This analysis does not include expenses of initial
equipment and maintenance nor does it include savings from other
nutrients and reduced disposal.
Table 11. Energetic and Economic Analysis of Feeding
ODML to Swine3
b
Aeration Expenses
Dffi c K Cal $ d
19.8 17,050 0.40
Otter expenses:
Initial equipment
Maintenance and repair
Protein Saving*
K Cal f $ *
16,920 0.80
Other saving*:
minerals
Vitamins
Water
Reduced disposal
Odor control
Vet
K Cal $
- 130 +0.40
Finishing phase of production, 100 to 200 Ib. in 60 days.
b Operating expenses only.
c Electricity requirement, 0.33 WH/Day (p.38 Jones at al., 1971).
d Electricity at $0.02/WH.
e Baaed on the OWL supplying 1/5 of the 40 Ib. of soybean seal.
f Gross energy of soybean Meal, 4.66 K Cal/Cot (Diggs et al., 1965).
I Soybean Mai at $200.00/Ton
250
-------
Studies comparing samples of pork chops and roasts from hogs fed ODML
and from control hogs showed that the taste and odor were not influenced
by feeding the aerobically sustained product (Wax et^ al., 1972). Rep-
resentative samples of all tests have passed state meat inspection in
Illinois.
There have, however, been some health problems and some unexpected pig
deaths. High nitrate levels in the ODML were suspected of causing
deaths in one experiment in which the mixed liquor had been aerated for
a considerable time without any hogs in the building. High nitrate
levels would be expected under this condition (no new feed for the
microorganisms). Another problem has been the survival of intestinal
worm eggs that are excreted into the oxidation ditch and are refed in
the ODML. No simple method of killing the worm eggs in the ODML has
been found. The problems of killing the parasites in biologically
treated sewage was discussed by Liebmann (1964). Heating to a temper-
ature of 144F. for a short time was the most successful method of kill-
ing worm eggs.
Other studies are underway at the University of Illinois to test the
nutrition of various forms of ODML for feeding to poultry and cattle,
as well as to swine. A new building for 200 beef cattle with an oxi-
dation ditch beneath slotted floors is now available (Bauling e^ a^.,
1973).
SOME OTHER PROJECTS UTILIZING AEROBICALLY
TREATED LIVESTOCK WASTES
Vetter et^ al. (1972) reported the use of beef cattle ODML in situ in
the diets for beef cattle. The results of that study suggest that
aerobically processed livestock wastes have an acceptable nutritional
value and can be effectively used as a partial protein and mineral
supplement. No animal health problems associated with feeding the
processed wastes or with meat quality were reported.
Studies at Purdue University have shown that aerobic micro-organisms
can convert the soluble organic matter in dairy cattle wastes into a
biomass containing 30 percent crude protein, Nye et al. (1972). This
biomass product was harvested and fed to laboratory rats for up to 20
percent of their diet with no dilatory effect. However, the rats could
not use the product as their only protein supplement.
Orr et al. (1972) reported amino-acid contents of swine ODML similar to
those in the University of Illinois studies. They also reported of
various schemes for refeeding the ODML from oxidation ditches that had
been in continuous operation for two years.
Diesch et al. (1971) reported a study at the University of Minnesota
for detecting and measuring the survival time of leptospires in aerated
beef cattle manure, using a model oxidation ditch. A maximum survival
time of 18 days was measured at a pH of 6.9.
257
-------
SUMMARY
The aerobic process of treating organic wastes produces a biomass with
a monocellular-type protein high in amino acids. This makes it of in-
terest as a protein supplement for animal diets that have a major pro-
portion of corn or other grain which is deficient in lysine and other
essential amino acids. The biomass also contains other nutrients, in-
cluding vitamins, minerals, and unidentified growth factors. The
health-related aspects of utilizing aerobically processed wastes are of
concern, but the aerobic method inherently retards pathogenic organisms.
The aerobic process is also a low-odor method of waste management that
is of interest to livestock producers. However, the amount of energy
required for aeration may be discouraging.
This paper reviews some of the major projects of analyzing the amino-
acid content of aerobically treated sewage and livestock wastes and of
evaluating the product as a protein supplement in the diets of live-
stock. Although the amino-acid content is similar for aerobically
treated municipal wastes and livestock wastes, extraneous materials can
be more closely controlled in livestock wastes than in municipal sewage.
A method developed at the University of Illinois in recent years
utilizes oxidation-ditch mixed liquor (ODML) in situ, supplying drink-
ing water as well as protein and other nutrients. Crude protein in the
ODML varies from 30 to 46 percent, the latter value is as high as in
soybean meal. Also, lysine and other amino acids essential to growth
can be as high in concentrated ODML as in soybean meal. This method
avoids the ordinary expenses generally associated with recycling. It
also offers two obvious advantages: minimizing pollution and realizing
a new source of nutrients. The present costs of soybean meal make the
method economically feasible and energetically attractive. However, a
more efficient method of oxidation is needed. Even so, the aerobic
process offers possibilities for a least-cost method of waste manage-
ment that has several advantages over alternate methods. Obviously,
the acceptance of the use of this monocellular protein product in the
diets of livestock will require some explanation and education.
252
-------
REFERENCES
1. Arden, E. and W. T. Lockett. 1914. Experiments on the oxidation of
sewage without the aid of filters. J. Soc. Chem. Ind. (London)
33:523-539.
2. Bauling, D. B., W. D. Boston, and D. L. Day. 1973. A beef confine-
ment building with an oxidation ditch. Amer. Soc. of Agri. Engin.
Paper 73-4544.
3. Becker, D. E., A. H. Jensen, and B. G. Harmon. 1966. Balancing
swine rations. Circular 866, Cooperative Extension Service, Uni-
versity of Illinois at Urbana-Champaign.
4. Bouthilet, R. J. and R. B. Dean, 1970. Hydrolysis of activated
sludge. Proc., Fifth International Water Pollution Research Con-
ference. July-Aug.
5. Day, D. L. and B. G. Harmon. 1972. A recycled feed source from
aerobically processed swine wastes. Amer. Soc. of Agri. Engi.
Paper 72-954.
6. Diesch, S. L., B. S. Pomeroy and E. R. Allred. 1971. Survival and
detection of leptospires in aerated beef cattle manure. Proc.,
International Symposium on Livestock Wastes. Amer. Soc. of Agri.
Engin. Publication PROC 271:263-266.
7. Diggs, B. G. , D. E. Becker, A. H. Jensen and W. H. Norton. 1965.
Energy value of various feeds for the young pig. J. Anim. Sci.,
24(2):555-558.
8. Firth, J. A. and B. C. Johnson. 1955. Sewage sludge as a feed in-
gredient for swine and poultry. Agr. and Food Chem. 3(9) :795-796.
9. Gouwens, D. W. 1966. Influence of dietary protein and fiber on
fecal amino acid excretion. Unpublished M.S. Degree Thesis, Univ.
of 111. at Urbana-Champaign.
10. Hackler, L. R. 1958. Dried activated sewage sludge as a nitrogen
source for ruminants. Unpublished Ph.D. Thesis. Univ. of 111. at
Urbana-Champaign.
11. Hackler, L. R. , A. L. Neumann, E. E. Hatfield, and B. C. Johnson.
1957. Dried activated sewage sludge as a nitrogen source for
ruminants. Abstract in J. of Anim. Sci. 16(4):1090.
12. Harmon, B. G. , D. E. Becker, A. H. Jensen, and D. H. Baker. 1969.
Nutrient composition of corn and soybean meal. J. of Anim. Sci.,
28(4):459-464.
253
-------
REFERENCES (cont'd.)
13. Harmon, B. G., D. L. Day, A. H. Jensen, and D. H. Baker. 1972.
Nutritive value of aerobically sustained swine excrement. J. Anim.
Sci. 34(3):403-407.
14. Harmon, B. G., D. L. Day, D. H. Baker, and A. H. Jensen. 1973.
Oxidation-ditch mixed liquor as a source of water and nutrients.
Abstract in J. of Anim. Sci. 37(1):280.
15. Harmon, B. G., D. L. Day, D. H. Baker, and A. H. Jensen. 1973A.
Nutritive value of aerobically or anaerobically processed swine
waste. J. Anim. Sci. 37(2):510-513.
16. Holmes, L. W. J. 1968. Concentration of proteinaceous solids from
aerated swine manure. Unpublished M.S. Thesis, Univ. of 111. at
Urbana-Champaign.
17. Holmes, L. W. J., D. L. Day, and J. T. Pfeffer. 1971. Concen-
tration of proteinaceous solids from oxidation ditch mixed liquor.
Proc., International Symposium on livestock wastes, Amer. Soc. of
Agri. Engin. PROC-271:351-354.
18. Hurwitz, E. 1957. The use of activated sludge as an adjuvant to
animal feeds. Proc., Twelfth Industrial Waste Conference, Purdue
Univ. Engineering Bulletin Ser. 94:395-414.
19. Jones, D. D., D. L. Day, and A. C. Dale. 1971. Aerobic treatment
of livestock wastes. Univ. of 111. Agri. Exp. Sta. Bulletin 737 in
cooperation with Purdue Univ.
20. Liebmann, H. 1964. Parasites in sewage and the possibilities of
their extinction. Proc., The Second International Conf., Advances
in Water Pollution Research, Edited by J. K. Baars, Pergamon Press,
Vol. 2:269-288.
21. Nye, J. C., A. C. Dale, T. Wayne Perry, and E. J. Kirsch. 1972.
Recovering protein from animal waste. Amer. Soc. of Agri. Engin.
Paper 72-955.
22. Orr, D. E., E. R. Miller, P. K. Ku, W. G. Bergen, D. E. Ullrey,
and E. C. Miller. Swine waste as a nutrient source for finishing
pigs. Mich. State Univ. Report of Swine Research 232:AH-SW-7319.
23. Pillai, S. C., M. I. Gurbaxani, and K. P. Menon. 1952. Influence
of activated sludge on certain pathogenic bacteria. Indian Med.
Gaz. 87:117-119-
254
-------
REFERENCES (cont'd)
24. Filial, S. C., E. G. Srinath, and M. L. Mathur. 1967. Activated
sludge as a feed supplement for poultry. Water and Waste Treatment.
May-June.
25. Schendel, H. E. and B. C. Johnson. 1954. Activated sewage sludge
as a source of vitamin B for the pig. Agri. and Food Chem.
2(9):23-24.
26. Vetter, R. L. , R. D. Christensen, G. Frankl, and W. R. Masch. 1972.
Feeding value of animal waste nutrients from a cattle confinement
oxidation ditch system. Leaflet R170, Anim. Sci. Dept., Iowa State
Univ.
27. Wax, J. E., B. G. Harmon, and G. R. Schmidt. 1972. Effect of liquid
feeding oxidation ditch mixed liquor on the palatability of pork.
Abstract in J. Anim. Sci. 35(5):1100.
255
-------
Grass Filtration for Final Treatment of Wastewater*
by
R. M. Butler, J. V. Husted and J. N. Walter**
INTRODUCTION
Grass filtration is one of three systems for land treatment of waste-
water1 »2»3. xhe other land treatment systems, spray irrigation and
rapid infiltration, utilize the plant root zone and the soil profile
as a filter medium to renovate wastewater. Grass filtration waste-
water treatment systems are designed to utilize the soil surface and
plant cover as the filter medium. The treatment mechanisms in the
grass filtration system may include physical removal of particulate
matter from the water, chemical adsorption of ions in solution on the
surface of soil particles, uptake of nutrients in solution by plant
roots, and biological treatment by microorganisms. In grass filtra-
tion systems, wastewater is applied along the top of a sloping site
and flows through the soil-plant filter with subsequent runoff. The
runoff from the grass filtration systems can be returned to a stream,
held in a pond or reservoir for reuse, or used for ground water re-
charge. The quality of the runoff water must be compatable with the
quality standards of the receiving stream. The runoff water quality
depends on the nature of the wastewater, the characteristics of the
site, the type of vegetation, and the operating methods of the system.
ADVANTAGES
Grass filtration systems require less extensive wastewater piping
systems and less land area than spray irrigation systems. If adequate
renovation can be attained by grass filtration, savings in terms of
wastewater application equipment and land can be obtained. If treat-
ment by overland flow is adequate, land with low infiltration capacities
can be used for wastewater treatment. An additional advantage of the
* Authorized for publication as paper no. 4635 in the journal series
of the Pennsylvania Agricultural Experiment Station.
This investigation was supported by funds provided by the United
States Department of Interior, Office of Water Resources Research,
as authorized under the Water Resources Research Act of 1964 through
the Institute for Research on Land and Water Resources, The Pennsyl-
vania State University and the Pennsylvania Agricultural Experiment
Station.
** Department of Agricultural Engineering, The Pennsylvania State
University, University Park, Pa.
256
-------
grass filtration system is that the treated water remains on the soil
surface. This facilitates sampling and monitoring of treatment effec-
tiveness, and the treated effluent is readily available for recycling
or reuse.
EXAMPLES
The grass filtration system has been successfully used to treat food
industry wastewater. A comprehensive study of an overland flow system
for cannery wastewater treatment was conducted for the Campbell Soup
Company at Paris, Texas^. The results of the study indicate 92 to 99
percent removal of volatile solids, 86 to 93 percent removal of nitro-
gen and 50 to 60 percent removal or phosphorus. Preliminary tests of a
grass filtration treatment system for beef feedlot runoff water have
been successful^.
A spray-runoff treatment system for raw municipal sewage is being test-
ed by scientists at the Robert S. Kerr Environmental Research Labora-
tory . The experimental system produced an effluent that is of terti-
ary treatment quality without sludge production.
Only limited information is available on the feasibility of using grass
filtration for final treatment of municipal effluent. In a study con-
ducted by Wilson and Lehman?, municipal sewage effluent from an oxida-
tion pond was applied to grassed plots 1000 feet long for final polish-
ing prior to artifical recharge. During one trial, nitrogen and phos-
phate concentrations were reduced by approximately A and 6 percent,
respectively, during flow over the plot. They concluded from these
tests that the quality of the effluent obtained from their systems was
not suitable for recharge.
PROJECT OBJECTIVES
The primary purpose of the research, summarized in this paper, was to
determine if grass filtration can be used to remove nitrate and phos-
phate from secondary treated municipal sewage effluent. In addition,
the effects of various hydrologic parameters on the treatment process
were investigated. Factors studied in field and laboratory tests
included; detention time, flow rate, flow distance, application fre-
quency, and seasonal effects.
257
-------
PROCEDURE
Two sets of field tests and a laboratory study were conducted. In the
field studies, the effects of hydrologic variables and application fre-
quency on nitrate and phosphate removal were investigated. The effects
of detention time on nitrate removal were investigated in the labora-
tory.
HYDROLOGIC STUDY
Three plots 150 feet long by 20 feet wide were established on a 6 per-
cent slope in the Summer of 1972. A stand of reed canarygrass was
established and maintained on the plot area. Stations were installed
at 50-foot intervals on each plot to intercept the overland flow for
water quality samples and to monitor the flow rate. At each station
runoff was intercepted in 4-inch deep plastic lined trenches and di-
rected to an "H.S." flume equipped with a water level recorder to give
a continuous record of flow rate. Runoff water quality samples were
taken periodically from the outfall of the flume. Three-inch diameter
aluminum pipes perforated with 3/4-inch diameter holes spaced 6 inches
on center were used to apply the water at the top of each plot and to
redistribute the effluent below the monitoring stations 50 and 100 feet
down the plot. Water meters were used to monitor the amount of water
applied to each plot.
The chemical composition of the municipal effluent illustrated in Table
1 is based on samples collected during 1971 and reported by Sopper and
Kardos8. The effluent is from the treatment plant which serves The
Pennsylvania State University and the borough of State College, Penn-
sylvania. Secondary treatment includes standard and highrate trickling
filters and a modified activated sludge process followed by final set-
tling.
Secondary treated municipal effluent was applied to the plots once each
week for six to eight consecutive weeks during the Winter, Spring, Sum-
mer, and Fall of 1973. Three wastewater application rates were com-
pared. The same application rate was applied to a plot during the
entire study. In the Winter of 1973, 10, 20, and 40 gpm were applied
for 8 hours each week. The results of the winter runs indicated that
the infiltration capacity of the soil was higher than anticipated.
For subsequent trials, the application rates were increased to 15, 30
and 60 gpm and the operating time reduced to 6 hours.
Water samples were taken from the inflow and from the outfall of each
flume at 1 1/2 to 2-hour intervals during each run. The nitrate and
phosphate concentrations and the pH were determined for all samples.
Total Kjeldahl nitrogen determinations were made on selected samples.
255
-------
Table 1. Chemical composition of the secondary treated
municipal sewage effluent used in the study.
Constituent
PH
Nitrate-N
Organic-N
NH4-N
Phosphorus
Calcium
Magnesium
Sodium
Boron
Manganese
Minimum
7.4
mg/1
2.6
0.0
0.0
0.250
23.1
9.1
18.8
0.14
0.01
Maximum
8.9
mg/1
17.5
7.0
5.0
4.750
27.8
15.1
35.9
0.27
0.04
Average
8.1
mg/1
8.6
2.4
0.9
2.651
25.2
12.9
28.1
0.21
0.02
259
-------
APPLICATION FREQUENCY STUDY
Three parallel plots, each 20 feet wide by 150 feet long were installed
on a grassed slope. The plots had an uneven slope of 6 to 8 percent,
with the greater slope occurring near the lower end of each plot. Each
plot was seeded with a mixture of 3 parts of a commercial quick cover
seed mixture, 2 parts annual ryegrass, and 2 parts reed canarygrass.
The faster germinating ryegrass dominated the growth on each plot dur-
ing all runs. Effluent was distributed at the head of each plot with
perforated pipes similar to those used in the hydraulic study. Efflu-
ent collection and monitoring stations similar to those used on the
hydrologic study plots were installed at the bottom of each plot.
Three run sequences were conducted during the period from mid-June to
early November, 1973. During the first run sequence from June 13 to
July 20, effluent was applied to each plot at an approximate rate of
100 gpm. The second run sequence was a continuous flow study in which
effluent was applied 24 hours a day for 70 hours at a rate of 40-50
gpm. This run was conducted from August 13-16 on the plot which had
received effluent 2 times per week in the first run sequence. A third
run sequence, similar to the first, was conducted from September 17
through November 2 with an effluent inflow rate of 50 gpm.
Application frequencies during the first and third run sequences were
2, 3, and 6 times per week with durations of 3, 2, and 1 hours per
application, respectively. Each plot received approximately the same
total amount of effluent per week. The same application frequency was
used on a plot during an entire run sequence.
During the first few weeks of operation, the grass crop was in the
development stage. Grass height was maintained at 4 to 8 inches by
weekly or semi-weekly cuttings throughout the study. A rotary mower
was used and clippings were retained on the plot.
Samples of inflow and outflow were taken for all runs. During certain
runs, surface water samples were taken at five additional locations,
spaced 25 feet apart, down the plot. Water quality analyses conducted
on all samples included nitrate, phosphate, and pH. Total Kjeldahl
nitrogen determinations were made on selected samples.
LABORATORY STUDY
A laboratory study was conducted to determine the rate of nitrate re-
moval from secondary treated sewage effluent on the surface of reed
canarygrass sod. Three treatments were compared in the study: grow-
ing sod, dead sod, and bare subsoil. The sod and the subsoil were from
the grass filtration field test site. The dead sod was obtained by
drying a sample of growing sod for several weeks. Galvanized steel
containers 10 inches wide, 30 inches long and 6 inches deep were used.
To drain the containers, a 1-inch diameter perforated conduit was in-
serted across each end and a 1-inch deep bed of crushed limestone was
260
-------
placed on the bottom. Approximately 4 inches of sod or soil was placed
on top of the crushed stone.
The experiments were conducted in a controlled environment chamber with
a daytime temperature of 80°F and a nighttime temperature of 65°F. The
chamber was lighted by fluorescent and incandescent lighting approxi-
mately 14 hours per day. To simulate water flowing down a sloping plot,
the containers were placed on a frame that oscillated with an amplitude
of 1 inch and a frequency of 15 cycles per minute.
Effluent was applied to the treatments until there was 1/2 inch of free
water on the surface. Each day the effluent was drained from the con-
tainers and more effluent was applied. Samples of the effluent were
taken periodically from the surface water layer during the day for
nitrate-nitrogen analysis.
RESULTS
HYDROLOGIC STUDY
Nitrate and phosphate were the nutrients studied in greatest detail.
Nitrate removal is possible from two sources; plant uptake and denitri-
fication. Results from a detention time study showed that 50-foot
plots with application rates of 15, 30 and 60 gpm had detention times
of 15, 10 and 8 minutes, respectively. These flow-through times were
too short for any significant plant uptake of nitrate during a run.
Tables 2 and 3 present the percentage of nitrate removed from the
wastewater for two different methods of calculation. The values in
Table 2 come from a material balance in which the weight of the nitrate
applied was compared to the weight lost through infiltration and the
weight remaining in the runoff water. The result is a value for
nitrate removal that is corrected for dilution caused by melting snow
and rainfall. Table 3 is simply a comparison of inflow and outflow
nitrate concentrations. A comparison of the two tables shows to what
extent the melting snow in the winter and the rainfall in the spring
affect the reduction in nitrate concentration. The amount of precipi-
tation that occurred during the Summer and Fall runs was insignificant.
The amount of nitrate removal obtained in this study was quite low
compared to those reported for other overland flow studies. Informa-
tion reported by Law, et al9, provides a possible explanation for the
low nitrate removal. It was reported that a continuous flow for 5 days
or more was required before reductions in nitrate levels were obtained.
Since the system was operated only once a week for a relatively short
period of time, it is possible that anaerobic conditions were not
available for dentrification. In addition, the short detention times
may not have allowed adequate time for nitrate removal. The labora-
tory study has shown that detention times of several hours are re-
quired for a high percentage of removal, Another factor that makes
267
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Table 2. Effect of flow rate on the percent estimated nitrate loss
determined by a nitrate balance during four seasons.
SEASON
Winter
Spring
Summer
Fall
Low
8
4
3
0
Flow Ratea
Medium
Percent
5
2
1
1
High
3
2
4
-1 (gain)
a Winter rates for Low, Medium and High were 10, 20 and 40 gpm
respectively, other seasons had rates of 15, 30 and 60 gpm.
Table 3. Effect of flow rate on the percent change in nitrate
concentration during four seasons.
SEASON
Winterb
Springb
Summer
Fall
Low
51
17
7
2
Flow Rate3
Medium
54
12
4
1
High
33
13
-1 (gain)
a Winter rates for Low, Medium and High were 10, 20 and 40 gpm
respectively, other seasons had rates of 15, 30 and 60 gpm.
b High reductions in concentration for Winter and Spring resulted
from melting snow and rainfall.
262
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this study different from overland flow studies reporting higher ni-
trate removals was the nature of the wastewater. The wastewater was
highly nitrified secondary municipal effluent and contained relatively
small amounts of organic matter. Denitrifying bacteria require organic
carbon for a source of energy.
Phosphate removal occurs by plant uptake or by adsorption on the soil
particles. Since the water was detained on the plots for such a short
period of time, plant removal of phosphate should not have been impor-
tant during a run. Soil adsorption was possible because of the contact
of the water with the surface of the soil. The amount of phosphate
removed was low with an average of about 17 percent.
A statistical analysis was performed to determine which parameters
significantly influenced nutrient removal. Each increase in flow rate
resulted in a significant decrease in phosphate removal efficiency.
This indicated that contact with the soil surface is important in phos-
phate removal. Nitrate removal was not significantly changed by chang-
ing the flow rate from 15 to 30 gpm, but switching from 30 to 60 gpm
resulted in a significant decrease in nitrate removals. The effects
of flow rate on nitrate reduction present a further indication that the
time spent on the plots was not long enough at the flow rates used in
the study.
The distance traveled by the water also was included in the statistical
investigations. Significant decreases in the concentrations of both
nitrate and phosphate occurred after each 50 feet of flow. This is a
further indication that the most important parameter for nutrient re-
moval is detention time which depends on the flow rate and flow dis-
tance as well as the percent slope and the characteristics of the
vegetation.
The analysis showed differences exist from season to season. These
differences were partly caused by dilution from melting snow and rain-
fall which can vary greatly from year to year. From a one
year study, however, it is difficult to assign much importance to the
seasonal effects.
Grass yield data (Table 4) show the effects of the different applica-
tion rates. For the first 50 feet of the plot receiving 60 gpm, the
yield was 2.66 T/A (tons/acre) which was lower than all areas sampled
except the 50 to 100-foot section of the plot receiving 15 gpm. This
area received runoff from the first 50 feet of the 15 gpm plot which
was about 6 gpm. The maximum yield was 4.06 T/A for the 50 to 100-foot
section of the 60 gpm plot. The first 50 feet of the 30 gpm plot had a
yield of 3.27 T/A. The amount of infiltration is an important factor
in determining grass yield. The first 50 feet of the 60 gpm plot had a
lower yield because approximately 15 inches of water entered the plot
during each run. The first 50 feet of the 60 gpm plot and the first 50
feet of the 30 gpm plot each had 12 inches of water entering the soil
and produced the largest grass yields.
253
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Table 4. Grass yield for two harvests from 50-foot plot
sections receiving effluent at three flow rates.
Flow
Rate
gpm
15
15
30
30
60
60
Distance
Ft.
0-50
50-100
0-50
50-100
0-50
50-100
Yield - Tons
Harvest
I
1.60
1.33
2.03
1.72
1.20
2.92
per acre
II
1.09
0.90
1.24
0.96
1.46
1.14
dry matter
Total
2.69
2.23
3.27
2.68
2.66
4.06
264
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APPLICATION FREQUENCY STUDY
Results of the application frequency study were analyzed by comparing
nutrient reduction and flow rate relationships. First, mean nitrate-N
and PO^-P concentrations were compared for each of the 3 run sequences.
Second, the relationships between the rate of inflow and outflow were
examined for each run sequence. Both nutrient reduction and flow rate
relationships were examined for effects of application frequency.
First Run Sequence
Effluent was applied at 100 gpm to all plots during the first run se-
quence. Nitrate-N and PO^-P reduction apparently had some dependence
on application frequency. Comparison of mean nutrient concentration
for inflow and outflow indicated that greater overall nutrient reduction
was achieved on the plot receiving effluent 2-times per week. An 8.5
percent reduction in PO^-P was observed on the 2-times per week plot
while a 1.6 percent reduction occurred on the 6-times per week plot.
The lowest PC^-P and nitrate-N reduction was observed on the plot re-
ceiving effluent 6-times per week. Tables 5 and 6 summarize the results
of the first run sequence.
Inflow - outflow effluent flow rate relationships for each plot were
similar during the first run sequence. Outflow rate was approximately
one-third of the inflow rate once the entire plot had been wetted and a
steady rate of infiltration was approached. This condition was achiev-
ed for most runs approximately 45 minutes after inflow had started.
Thus, two-thirds of the effluent applied was lost through infiltration.
Second Run Sequence - Continuous Flow Study
Results of data collected during the continuous flow run indicate that
somewhat greater reductions in nutrient concentration were achieved.
Comparison of mean nutrient concentrations of inflow and outflow show
a 10.5 percent and 4.9 percent reduction for nitrate-N and PC^-P, re-
spectively. Variation of nutrient removal with time was minimal during
the continuous flow run. Table 7 summarizes data from the continuous
flow run.
Inflow during the run varied between 40 and 50 gpm due to scheduled
irrigation valve changes elsewhere in the effluent distribution system.
Outflow during the entire 70-hour run was approximately one-third of
inflow which is an indication of the relatively pervious soil with an
infiltration capacity of approximately 1 inch per hour.
Third Run Sequence
Inflow was approximately 50 gpm during the third or late summer run
sequence. Application frequency effects for nitrate were similar to
those observed during the first run sequence and are shown in Tables 8
and 9. The results for phosphate were different. There was an increase
265
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Table 5. Effect of effluent application frequency on mean nitrate
reduction during the early summer run sequence.
Samples in mean
Inflow (mg/1)
Outflow (mg/1)
% Reduction
Frequency
2
24
11.0
10.8
1.8
of Application
3
25
11.8
11.6
1.7
(per week)
6
35
10.1
10.1
0
Table 6. Effect of effluent application frequency on mean phosphate
reduction during the early summer run sequence.
Frequency of Application
Samples in mean
Inflow (mg/1)
Outflow (mg/1)
Z Reduction
2
21
5.11
4.93
8.5
3
23
5.03
4.93
2.0
(per week)
6
35
5.05
4.97
1.6
266
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Table 7. Mean nutrient reduction during the 70-hour mid-summer
continuous flow run.
Nutrient
N03-N P04-P
Samples in mean 10 10
Inflow (mg/1) 13.3 4.67
Outflow (mg/1) 11.9 4.44
% Reduction 10.5 4.9
267
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Table 8. Effect of effluent application frequency on mean nitrate
reduction during the late summer run sequence.
Frequency of Application
Samples in Mean
Inflow (mg/1)
Outflow (mg/1)
% Reduction
2
34
11.3
11.0
2.7
3
45
12.2
12.1
0.8
(per week)
6
74
12.1
12.1
0
Table 9. Effect of effluent application frequency on mean phosphate
reduction during the late summer run sequence.
Frequency of Application
Samples in Mean
Inflow (mg/1)
Outflow (mg/1)
% Reduction
2
34
5.27
5.19
1.5
3
45
5.98
6.06
-1.3*
(per week)
6
74
6.22
6.27
-0.8*
* Minus denotes increase
268
-------
in PO^-P concentration on the plots receiving effluent 3 and 6 times
per week. This increase may have been caused by washout of soluble
phosphorus from the increasingly dense grass clipping layer at the soil
surface.
Inflow-outflow effluent flow rate relationships were more varied and
possibly frequency dependent during the third run sequence. Outflow
rate was approximately one-tenth of inflow rate for the plot receiving
effluent 2 times per week, one-quarter of inflow rate for the 3-times
per week plot, and one-third for the 6-times per week plot. The varia-
tions observed appeared to be the result of antecedent soil moisture
conditions since the 2-times per week plot responded with an outflow
rate nearly one-third of the inflow rate when run immediately following
an all-night rain.
LABORATORY TESTS
During the first two days of the experiment, there were only slight
decreases in the nitrate content of the effluent on the dead sod. After
the second day, the daily results were relatively consistent. The ni-
trate concentration of each wastewater sample was converted to a ratio
of nitrate concentration of the sample to the nitrate concentration of
the effluent applied that day. The initial nitrate concentration ranged
from 12 to 14 mg/1 nitrate-N. A set of curves for the data for the
third through ninth days of the experiment was obtained using an expo-
nential relationship and regression analysis (Figure 1).
The average reductions in nitrate concentration after 8 hours of incu-
bation were 95 and 72 percent for the growing sod and the dead sod,
respectively. The difference in these values can probably be accounted
for by plant removal of nitrate. The effluent incubated on the bare
subsoil increased in nitrate content during each day. This result in-
dicates that there was not enough organic carbon in the effluent to
support denitrification.
The results of the laboratory experiment help explain the results of
the field experiments. In the field, the flow-through time for the 150-
foot long plots was approximately 30 minutes. Under laboratory condi-
tions, a 22 percent reduction in nitrate concentration was obtained on
the growing sod in this time. The maximum reduction in nitrate content
obtained in the field was approximately 10 percent during the continuous
flow test. The difference between this value and the laboratory value
for the same detention time is probably due to the fact that the labor-
atory test was for a batch system and the field tests were for a con-
tinuous flow system subject to temperature variations. If under the
best field conditions, the removal rate is about one-half that obtained
in the laboratory, detention times of about 12 hours would be required
in the field to reduce the nitrate concentration from 12 to 1 mg/1
N03-N. Additional laboratory tests are being conducted to determine
the effects of initial nitrate concentration of the effluent and tem-
perature on nitrate removal.
269
-------
BARE
SUBSOIL
GROWING
SOD
3456
TIME, HOURS
8
Figure 1. Nitrate removal from wastewater during
incubation on three laboratory treatments.
270
-------
CONCLUSIONS
No significant reduction in phosphate or nitrate concentrations was
observed in secondary treated municipal sewage effluent after grass
filtration with the flow rates, plot slopes, and plot lengths used in
this study. The results of the tests will be useful, however, in plan-
ning future experiments in which the application procedure and the plots
will be modified to improve nutrient removal.
The results of the field studies indicate that the removal of both
phosphate and nitrate increased as the application frequency was de-
creased from 6 times to 2 times per week. The duration of application
was increased as the frequency was reduced so that approximately the
same depth of effluent was applied to each plot. Comparison of samples
taken during each application period indicated only slight differences
in both nitrate and phosphate renovation during a run. These results
suggest that the grass filtration system should be operated with runs
of long duration separated by several days of rest. The field tests
also indicated that leaving grass clippings on the plot surface may
result in increased phosphate concentrations as phosphate is leached
from the decomposing grass into the wastewater.
The greatest problem to be overcome in designing a grass filtration sys-
tem to remove relatively high nitrate concentrations from municipal
sewage effluent is to obtain sufficiently long detention times. In
laboratory tests, 5 to 6 hours were required to achieve a 90 percent
reduction in nitrate concentration from effluent with an initial con-
centration of 12 mg/1 N03~N. Under field conditions, the detention
times would probably have to be 1 1/2 to 2 times the laboratory values
for a similar reduction in nitrate concentration. Detention times of
this length could be obtained by restricting the flow rate over the
plots with barriers or by recycling the effluent.
277
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References Cited
1. Reed, S. C., et al, "Wastewater Management by Disposal on the Land",
Special Report 171, Corps of Engineers, U. S. Army, Cold Regions
Research and Engineering Laboratory, Hanover, New Hampshire, 1972,
183 p.
2. Thomas, R. E. and C. C. Harlan, Jr., "Experiences with Land Spread-
ing of Municipal Effluents", in Proceedings of Conference on Land
Disposal of Municipal Effluents and Sludges, EPA-902/9-73-001, pp.
212-225, March 1973.
3. Stevens, R. M., et al, Green Lands and Clean Streams, A Report for
the Study of Federalism on The Beneficial Use of Waste Water through
Land Treatment, Temple University, 1972, 330 p.
A. Mather, J. R., Editor, "An Evaluation of Cannery Waste Disposal by
Overland Flow Spray Irrigation", Publications in Climatology, Vol.
XXII, No. 2, C. W. Thornthwaite Associates, Elmer, New Jersey, 1969,
73 p.
5. Thomas, R. E. and C. C. Harlin, Jr., "Experiences with Land Spread-
ing of Effluents", pp. 212-225.
6. Thomas, R. E., "Spray-Runoff To Treat Raw Domestic Wastewater",
presented at The International Conference on Land for Waste Manage-
ment, Ottawa, Canada, October 1973, 11 p.
7. Wilson, L. G. and Lehman, G. S., "Grass Filtration of Sewage Efflu-
ent for Quality Improvement Prior to Artificial Recharge", presented
at The 1966 Winter Meeting, American Society of Agricultural Engi-
neers, Chicago, Illinois, 1966.
8. Sopper, W. E., and L. T. Kardos, "Vegetation Responses to Irrigation
with Treated Municipal Wastewater", Recycling Treated Municipal
Wastewater and Sludge through Forest and Cropland, The Pennsylvania
State University Press, 1973, pp. 271-294.
9. Law, J. P., R. E. Thomas, and L. H. Myers, "Nutrient Removal from
Cannery Wastewater by Spray Irrigation of Grasses", U. S. Dept. of
Interior, FWQA Water Pollution Research Series, 16080, 73 p., cited
by Reed, S. C., et al, Wastewater Management by Disposal on the
Land, Cold Regions Research and Engineering Laboratory, Hanover,
New Hampshire, 1972, pg. 86.
272
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USE OF CATTLE FEEDLOT RUNOFF IN CROP PRODUCTION l
by
G. W. Wallingford, L. S. Murphy, W. L. Powers,
H. L. Manges, and L. A. Schmid 2
ABSTRACT
Land disposal of beef-feed lot-lagoon (run-off) water was studied.
Lagoon water was applied during the summers of 1970, 1971, 1972 and
1973 by furrow irrigation to a si Ity clay loam soil. After four
years the five treatments averaged 0, 7, 13, 22 and 37 cm/yr. Corn
(Zea mays L.) forage yield and plant content of N, P, K, Ca, Mg, and
Na were measured. Surface soil samples and soil cores were taken
from the plots after harvest each year.
Electrical conductivity ranged from 1.6 to 7.6 (3.1 average) mmho/cm
in the lagoon water applied at the study site and from 1.0 to 12.8
mmho/cm in samples taken from 12 Kansas feedlots. Electrical conduc-
tivities of extracts from saturated pastes of the surface soil samples
were increased linearly by accumulative treatment all years. The 1970,
1971 and 1972 soil cores showed accumulations of NOa-N, P, K, and Na
in the top 30 cm at all treatment rates. Movement of NO^-N and Na
down to 100 cm was noted in 1971 in cores from plots receiving 43 cm/yr.
Movement of NOs-N down to 240 cm was recorded in 1972 in cores from
plots that had received 20 and 41 cm/yr. Extractabie Ca and Mg in
the soil cores was not affected by treatment. Corn forage yields were
a linear function of treatment in 1970 and a quadratic function in
1971, 1972 and 1973. The positive effect on yield was attributed to
increased soil fertility; the relative decreases at the higher rates
were attributed to increased soil salinity. Maximum yield and uptake
of N and P were reached at the 13 cm/yr disposal rate in 1971 and 1972,
and at the 22 cm/yr rate in 1973.
Key Words: Feed lot waste, feed lot lagoon, waste-water,
forage production, irrigation, soil salinity.
Contribution No. 1427, Department of Agronomy, and Contribution
No. 200, Department of Agricultural Engineering, Kansas Agricultural
Experiment Station, Manhattan, Kansas 66506
Research Assistant, Agronomist, Associate Agronomist, Assistant
Agricultural Engineer, and Associate Civil Engineer, Kansas State
University, Manhattan, Kansas. The work reported here was partially
supported by the Environmental Protection Agency, Water Quality
Office, under Grant Nos. 13040 DAT and S800923.
273
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INTRODUCTION
The increasing size of beef cattle feed lots has been paralleled by an
increase in the magnitude and incidence of their waste disposal
problems. The Kansas State Department of Health requires that runoff
detention lagoons hold three inches of surface runoff from feeding
areas and that these lagoons be emptied as soon as practical to main-
tain retention capacity (3). The most common method of disposal has
been to apply lagoon water to adjacent crop and pasture land. High
transportation costs dictate that maximum rates be applied to these
fields close to the source.
Care must be taken so that the soil used as the disposal medium does
not become polluted. Characterization of beef-feedlot runoff has
shown it to vary widely in chemical composition, and generally to be
high in total salt content (1,2,5,6,7,8,9). After runoff arrives at
a lagoon, evaporation can further increase salt concentrations. When
such lagoon water is applied to a soil, some of the salts can be used
as plant nutrients to increase productivity but excess salts can
create soil salinity and dispersion problems.
Only limited data are available on effects of beef-feed lot-lagoon
water on soil properties and plant growth. Travis, et al. (10),
found total salts increased by 200$ and infiltration declined to
zero in soil columns from four Kansas soils after inundation with
lagoon water with an electrical conductivity (EC) of 13.4 mmhos/cm.
They suggested that the higher proportion of monovalent cations Na ,
K+ and NHt in such soil could have dispersed colloids and led to the
cessation of infiltration.
Satterwhite and Gilbertson (8) found in a one-year field study that
sprinkler applications of up to 30.5 cm of lagoon water increased
soil N, P, K, S, and Cl. They compared (in a greenhouse) the effects
of tap water, water taken from a lagoon in 1969, and water from the
same lagoon in 1970 on plant growth. Both lagoon waters increased
total salts in the soil more than did tap water. Growth of nine
grass species was enhanced by tap water and by the 1970 lagoon water,
but was inhibited by the 1969 lagoon water.
We evaluated how growth and composition of corn (Zea mays L.) forage
and chemical properties of a Kansas soil were affected by furrow
irrigation with beef-feed lot-lagoon water.
MATERIALS AND METHODS
The study area was located 6 miles north of Pratt, Kansas, on a siIty
clay loam soil with a cation exchange capacity of 19 meq/100g and a
pH of 7.0. Lagoon water was obtained from a nearby commercial feed lot
274
-------
and was applied by furrow irrigation in increments of 5 and 10 cm
during the summers of 1970, 1971, 1972 and 1973 to plots 9 m wide and
61 to 111 m long. Five treatments were replicated four times'. In 1970
and 1973 the last 10 cm increment of lagoon water was not applied to
the four plots receiving heaviest applications until after harvest.
Inflow and outflow was measured on each plot. The average amounts
applied after four years were calculated to be 0, 7, 13, 22 and 37 cm
per year for the four replications. The two replications that were
sampled for soil core analysis had received an average of 0, 8, 17,
26 and 45 cm per year by the fall of 1970, 0, 8, 15, 23 and 43 cm per
year by the fall of 1971, and 0, 7, 14, 20 and 41 cm per year by the
fall of 1972. Samples of the lagoon water were collected during each
application and analyzed for Ca, Mg, Na, and K by standard atomic
absorption and flame photometric_procedures, for ammonium-nitrogen
(NI-U-N) and nitrate-nitrogen (N03-IM) by steam distillation procedures
(4), and for soluble salts by resistance measurements using a Wheat-
stone bridge.
To compare composition of the material being applied at the study site
with that found at other feedlots, samples were taken from 12 locations
in Kansas during early July of 1970 and 1971, and were analyzed in the
manner described above. The lagoons were sampled at four depths in
1970: 5, 50, 100, and 200 cm. Chemical composition did not vary with
depth in 1970, so a single sample was taken at 15 cm from each lagoon
in 1971.
All plots received a preplant irrigation in the spring of 1971 and
1972. Additional well water was applied during the growing seasons
to the control plots and to plots receiving the lower lagoon-water
treatments so all plots received approximately equal volumes of liquid.
No chemical fertilizers were applied.
Corn silage yields (mechanical harvest) were recorded, and samples
from each plot were analyzed for Ca, Mg, Na, and K by atomic absorp-
tion and flame photometry after a nitric-perchloric acid digestion.
Nitrogen and P were determined by steam distillation and colorimetric
procedures respectively after a sulfuric acid digestion. The 1972
and 1973 forage was analyzed for nitrate-nitrogen by hot-water extrac-
tion and subsequent analysis by steam distillation.
Composite surface soil samples (0 to 15 cm) were taken at 18 locations
in each plot after harvest. Extracts from a water-saturated paste
were analyzed for soluble salts by resistance measurements. Cores
were taken after harvest to a depth of 2 m in 1970 and 3 m in 1971
and 1972 from plots in two replications. The surface meter of each
core was divided into 10 cm increments and analyzed for extractable
Ca, Mg, Na, and K by atomic absorption and flame photometry. For
the 1970 and 1971 cores the extraction procedure included an initial
extraction with methanol to remove the cations not on exchange sites.
This was followed by extraction with 1.0 N ammonium acetate, pH 7.0,
275
-------
to remove the exchangeable cations. The 1972 cores were extracted with
ammonium acetate only. Except for Na, only insignificant concentra-
tions were found in the methanol extract. The total cations extracted
by these two methods are referred to as extractable Ca, Mg, Na, or K.
The surface meter increments also were analyzed for Bray P-1 extract-
able P. The lower depths were divided_into 20 cm increments and, along
with the upper depths, analyzed for N03-N by steam distillation tech-
niques (4). The 1972 cores were analyzed for soluble salts to a depth
of one meter by resistance measurements of extracts from water-satur-
ated pastes.
RESULTS AND DISCUSSION
Lagoon Water Analyses,
Results of analyses of the lagoon water applied are given in Table 1.
Total salt concentration, indicated by the electrical conductivity^
was high. Concentrations of the monovalent cations NH4, K , and Na
were considered to be high. The high and low values of all measure-
ments show how the composition of the lagoons of a single feed lot can
vary. This variation was not accounted for in our interpretation of
soil and plant measurements.
Table 2 includes the analysis of the lagoon samples taken at the 12
Kansas locations. Wide variation in composition of samples among
lagoons each year was similar to variation of lagoon water applied.
There was little correlation between the 1970 and 1971 data from the
same locations. Lack of uniformity between lagoons and between years
makes it essential that analysis of lagoon waste water be known before
disposal to predict how the material will affect soil properties and
plant growth.
Effects On Soil Chemical Properties
Electrical conductivities of saturation extracts from 1970, 1971 and
1972 surface soil samples were linearly related to the accumulative
cm of lagoon water applied (Fig. 1). The EC values of plots receiving
an average of 7 cm/yr were not much higher than those of the control
plots. Plots receiving 13, 22, or 37 cm/yr had EC values generally
higher than the control plots. Since the EC measurement is directly
related to total water soluble salt content of a soil, the three
heaviest treatments provided more salts than could be used by the
corn plants or leached lower into the profile. High R2 values for
all three years (0.878, 0.875 and 0.914) indicate good correlation
between the EC measurement and accumulative amounts of lagoon water
applied. This suggests that EC measurements could be used to estimate
amounts of lagoon water that have been applied to a soil.
275
-------
To improve the graphical presentation of the soil-core analysis data,
measurements taken from two plots receiving the same treatment were
averaged. Data points were further reduced by combining data from
adjacent depth increments, so that in Figs. 2, 3, 4, and 5 values are
plotted for depths of 10, 30, 50 cm, etc., rather than at depths of
5, 15, 25, 35, 45, 55 cm, etc.
Fig. 2 gives N03-N concentrations in the 1970, 1971 and 1972 soil cores,
In 1970, all plots that received lagoon water had higher NOs-N concen-
trations at the 10 and 30 cm depths than did control plots. No NOs-N
accumulated deeper than 30 cm in 1970. Soil cores taken in 1971 showed
accumulations at 10, 30 and 50 cm depths at all dispersal rates. The
23 and 43 cm/yr rates caused particularly high concentrations at 10
and 30 cm depths. A N03-N peak was found at 100 cm under the plots
that received 43 cm/yr. In 1971 peaks were less well defined at 200
and 240 cm under the plots that had received lagoon water treatments
of 15 and 43 cm/yr, respectively. By 1972 there was significant
movement of N03-N to the 240 cm depth under plots that had received
20 and 4_1 cm/yr. Because the control plots received no additional N,
their NOs-N levels were lower than what would be expected in an irri- .
gated soil being managed for maximum corn production. The two highest
disposal rates were, therefore, the only treatments that caused signi-
ficant accumulations of NOa-N in the soil profiles.
All disposal rates caused extractable P to accumulate to a depth of
10 cm in the 1970, 1971 and 1972 soil cores (Fig. 3). Movement to the
50 cm depth was found under plots receiving 41 cm/yr in 1972. The
general lack of P movement indicates that the soil's capacity to
immobilize the added P had not been exceeded except possibly at the
highest application rate.
Analyses of the 1970 cores for extractable Na, K, Ca, and Mg, and
analyses of 1971 and 1972 cores for extractable Ca and Mg showed no
trends due to treatment. Extractable K was increased to a depth of
10 cm in the 1971 cores and to 30 cm in the 1972 cores at all disposal
rates (Fig. 4). Movement below these depths was probably restricted
by exchange reactions with clay colloids. Extractable Na accumulated
at all depths in the 1971 and 1972 cores (Fig. 5). Deeper movement
of Na than K reflects greater competitiveness of K for cation exchange
sites. Soluble salts as indicated by the EC measurements of the 1972
soil cores had increased throughout the top meter under plots receiving
14, 20 and 41 cm/yr (Fig. 6).
Effect On Yield, Elemental Uptake And NO^-N Content Of Corn Forage
Thirty-five cm of lagoon water had been applied to the plots receiving
heaviest treatments by the time the 1970 corn forage was harvested.
There was a general linear trend in yield due to treatment in 1970
(Fig. 7). That positive effect on yield in 1970 probably resulted
from increased soil fertility (nutrients in the lagoon water).
277
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Maximum yields were recorded at the 13 cm/yr rate in 1971 and 1972 and
at the 22 cm/yr rate in 1973. Yields fell off at higher application
rates, which gave a quadratic relationship between accumulative appli-
cations and yield in 1971, 1972 and 1973 (Fig. 7). The initial in-
crease in yield again can be attributed to improved soil fertility,
while the yield decline at the higher rates likely resulted from salt
buildup in the soil (Fig. 1). Yield depression was less in 1973
probably because of higher rainfall that year. The yield decline was
relative; all plots receiving lagoon water yielded more than control
plots.
Uptake of N, P, K, Ca, Mg, and Na was calculated from the yield and
elemental analyses of the corn forage. Linear and quadratic coeffi-
cients and intercepts from a regression analysis on uptake as affected
by the accumulative applications of lagoon water are presented in
Table 3. In 1970 uptake of all elements increased linearly with
applications as did the 1970 yield. Uptake in 1971 and 1972 was a
quadratic function of treatment as was yield. Maximum uptake of most
elements occurred at about the same application rate that gave the
highest yield (Figs. 7, 8, 9 and 10).
The concentration of nitrate-nitrogen increased linearly with accumu-
lative treatment in the 1972 and 1973 corn forage (Fig. 11). Two of
the values measured were high enough to be considered dangerous to
livestock if ingested.
SUMMARY AND CONCLUSIONS
Feed Iot-1agoon water can contain large amounts of salts, particularly
the monovalent cations. Considerable variations in composition of
feed lot-1agoon water is to be expected with varying rainfall, runoff,
and evaporation. Continued applications of feed lot-1agoon water
significantly increased salt content of soil we studied. Increases
in the electrical conductivity of the soil were linearly related to
the amount of lagoon water applied. The heaviest lagoon-water treat-
ments contributed more salts than could be utilized by corn plants or
leached into the lower portions of the soil profile. The resultant
accumulations could have produced higher osmotic pressures in the soil
solution. Nitrate-nitrogen accumulated in the soil from the 22 and
37 cm/yr lagoon water applications reflecting the relatively high
nitrogen content of lagoon water. Phosphorus also accumulated with
lagoon water applications but accumulations were mostly restricted to
the surface 20 cm, reflecting lack of movement of P in the soil.
Maximum yields of corn forage occurred at an average application rate
of 13 cm/yr after the second and third year and at 22 cm/yr after the
fourth year. At higher rates, yields declined. Maximum removal rates
of applied nutrients, an important consideration in maintaining viabil-
ity of soil, were achieved at the same application rates that produced
maximum yields.
278
-------
Disposal of feed lot-lagoon water can produce excess accumulations of
salts if soil composition is not closely monitored. Large amounts of
monovalent cations may contribute to undesirable conditions by restrict-
ing water infiltration by dispersion of soil colloids. Yearly soil
analyses of disposal areas are recommended. Results of this investiga-
tion suggest that electrical conductivity measurements can be used to
estimate the amount of lagoon water previously applied and to predict
effects of applications on soil chemical conditions and plant growth.
LITERATURE CITED
1. Clark, R. N., and B. A. Stewart. 1972. Amounts, Composition, and
Management of Feedlot Runoff, Tech. Report No. 12, Texas Agr. Exp.
Station.
2. Gilbertson, C. B., T. M. McCalla, J. R. Ellis, 0. E. Cross, and
W. R. Woods. 1971. Runoff, solid wastes, and nitrate movement
on beef feedlots. J. Water Poll. Control. Fed. 106:5457.
3. Kansas State Board of Health Regulations, 1970, Chapter 28,
Article 18. Kansas State Department of Health, Environmental
Health Series, Topeka, Kansas.
4. Keeney, D. R., and J. M. Bremner. 1966. Determination and
isotope-ratio analysis of different forms of nitrogen in soils.
Soil Sci. Soc. Amer. Proc. 30:583-587.
5. Manges, H. L., L. A. Schmid, and L. S. Murphy. 1971. Land
disposal of cattle feed lot wastes. Proc. Inter. Sym. Livestock
Wastes. Ohio State U. p. 62-65.
6. McCalla, T. M., J. R. Ellis, and C. B. Gilbertson. Chemical
studies of solids, runoff, soil profile and groundwater from
beef cattle feedlots of Mead, Nebraska. Waste Management
Research, Proceedings of 1972 Cornell Agricultural Waste
Management Conference, p. 211-223. Graphic Management Corp.,
Washington, D.C.
7. Miner, J. R., L. R. Fina, J. W. Funk, R. I. Lipper, and G. H.
Larson. 1966. Stormwater runoff from cattle feedlots.
Management of Farm Animal Wastes. Amer. Soc. Agri. Eng.,
St. Joseph, Michigan.
8. Satterwhite, M. G., and C. B. Gilbertson. Grass response to
applications of beef-cattle feedlot runoff. 1972. Waste
Management Research, Proceedings of 1972 Cornell Agricultural
Waste Management Conference, p. 465-480. Graphics Management
Corp., Washington, D.C.
279
-------
9. Swanson, N. P., L. N. Mielke, J. C. Lorimor, T. M. McCalla,
and J. R. El Its. Transport of pollutants from sloping cattle
feedlots as affected by rainfall intensity, duration, and
recurrence. 1971. Livestock Waste Management and Pollution
Abatement, Proceedings of the International Symposium on
Livestock Wastes, p. 51-55. Amer. Soc. of Agri. Engr. St.
Joseph, Michigan.
10. Travis, D. 0., W. L. Powers, L. S. Murphy, and R. I. Lipper.
1971. Effect of feed lot lagoon water on some physcial and
chemical properties of soils. Soil Sci. Soc. Amer. Proc.
35:122-126.
280
-------
No
Co
Table 1. Elemental Composition And Electrical Conductivity Of Beef-Feed lot-Lagoon Water
Applied To Research Plots During 1970, 1971 And 1972.
High
Low
Average
Electrical
Conductivity
nnrnno/cm
7.6
1.6
3.1
Na
660
112
295
K
1840
259
671
Ca
615
83
225
Mg
239
35
87
Nht-N
mg/ i
179
4
73
NO^-N
63
1
13
Total
Sol i ds
18134
1879
4771
COD
6445
593
1868
Volati le
Sol ids
at
7>
44.4
27.1
37.8
-------
Table 2. Elemental Composition And Electrical Conductivity Of Beef-Feed lot-Runoff Lagoon
Samples Taken At 12 Locations In Kansas During July, 1970 and 1971. The 1970 Data Are
Averages Of Samples Taken At Four Depths: 5, 50, 100 and 200 cm. The 1971 Data Are
From A Single Sample Taken At 15 cm.
Location
1
2
3
4
5
6
7
8
9
10
11
12
Electrical
Conductivity
1970 1971
mmho/cm
3.1
2.7
3.3
1.0
4.2
6.3
8.6
12.8
7.3
*
#
— *
3.0
2.7
4.1
4.8
3.9
4.3
12.6
4.2
#
10.6
1.4
6.0
Na
1970 1971
142
139
221
73
268
339
653
1690
834
*
#
— *
122
220
293
329
335
299
1320
403
__ _ *
1460
317
500
K
1970 1971
387
166
330
52
550
826
1100
2030
752
#
#
*
583
325
604
617
729
708
1920
458
#
2210
483
750
Ca
1970 1971
ppr
152
101
160
65
141
177
523
403
212
*
#
#
101
100
158
127
143
135
310
136
*
108
101
187
Mg
1970 1971
74
61
85
34
97
78
153
189
112
*
*
— ~*
78
70
111
124
81
89
171
82
*
235
64
170
Total 1 norganic
N (NH^-N + NOa-N
1970 1971
195
164
151
16
220
130
366
207
221
*
*
*
145
119
167
161
61
218
543
127
#
136
133
143
Lagoon dry at sampling time.
-------
Table 3. Corn Forage Yield, Electrical Conductivity Of Soil
Saturation Extracts (EC), and Uptake By Corn Of Indicated Elements
In 1970, 1971, 1972 and 1973 As Affected By Accumulative Applications
Of Beef-Feedlot-Lagoon Water (cm). The Data Are Expressed As Factors
Of A Regression Equation: y = ax2 + bx + c.
Year
1970
1971
1972
1973
Measurement (y)
Yield (MT/ha)
N uptake (kg/ha)
P uptake (kg/ha)
K uptake (kg/ha)
Ca uptake (kg/ha)
Mg uptake (kg/ha)
Soi I EC (mmho/cm)
Yield (MT/ha)
N uptake (kg/ha)
P uptake (kg/ha)
K uptake (kg/ha)
Ca uptake (kg/ha)
Mg uptake (kg/ha)
Na uptake (kg/ha)
Soi I EC (mmho/cm)
Yield (MT/ha)
N uptake (kg/ha)
P uptake (kg/ha)
K uptake (kg/ha)
Ca uptake (kg/ha)
Mg uptake (kg/ha)
Na uptake (kg/ha)
Soi I EC (mmho/cm)
Forage Nitrate-
Nitrogen (ppm)
Yield (MT/ha)
Forage Nitrate-
Nitrogen (ppm)
R2
0.316
0.482
0.107
0.197
0.0
0.186
0.878
0.372
0.574
0.290
0.079
0.157
0.188
0.387
0.875
0.269
0.584
0.161
0.465
0.212
0.132
0.333
0.914
0.561
0.327
0.482
a
0.0
0.0
0.0
0.0
0.0
0.0
-0.00410*
-0.0221*
-0.00256*
-0.000190
-0.00280
-0.00139
-0.000212*
0.0
-0.00322*
-0.0177*
-0.00179
-0.0183*
-0.00237
-0.00117
-0.00106
b
0.498*
2.75*
0.388
1.60*
0.0890
0.0166*
0.425*
2.63*
0.264*
, 0.367
0.301
0.137
0.0261*
0.0191*
0.426*
2.91*
0.270
2.83*
0.350
0.170
0.00415*
0.0200*
5.29*
0.245*
2.26*
c
41.5
98.9
33.7
162
19.8
0.495
36.3
85.0
17.2
131
20.9
14.8
0.649
0.470
49.2
96.3
29.3
164
28.9
21.8
0.558
0.391
-8.86
33.8
75.7
* Coefficient significant at the 0.05 level.
283
-------
NO
s
0.0-
3.2H
2.11-
1.6-
0.0-1
FflU .19.70
10 20 3'0 . I'D
LflGOON WRTER. RCC. CM
FflLL 1972
£0
30 60 90 120 150
LRGOON WRTER. RCC. CM
FfllL 19.71
22 11 66 88 1 0
LRGOON WRTER. RCC. CM
Fig. 1.
The electrical conductivity (EC) of saturated paste extracts from surface
(0-15 cm) soil samples taken in the fall of 1970, 1971 and 1972 as affected
by accumulative applications of beef-feedlot-lagoon water.
-------
FflLL 1970
£ia
Kg
Qa
O—O CONTROL
«—• 8 CM/TERR
«—« 17 CM/TEflR
26 CM/TEflR
15 CM/TEflR
20CH
60
2UO
300
CONTROL
7 CM/TERR
1U CM/TERR
20 CM/TERR
Ul CM/TERR
8 16 2<1 32
NITR9TE-NITROGEN. PPM
FfiLL 1971
V 8 12 16 20
N1THHTE-N. PPM
FflLL 1972
B—m CONTROL
« » 8 CH/TEflR
15 CM/TERR
23 CM/TERR
43 CM/TEflR
300
30 US
NITRRTE-N. PPM
M>
r.
U !
Fig. 2.
The N03-N content of soil cores taken in the fall of 1970, 1971 and 1972 as
affected by depth and average yearly application rate of beef-feed lot-lagoon
water.
-------
FRLL 1970
MO
I
u
! .
80-
CONTROL
8 CH/TEflH
17 CH/TEflR
26 CM/TERR
MS CM/TEflR
100
"5 I'B 3'7 36
PHOSPHORUS. PPH
FflLL 1972
FflLL 19.71
'i,
CONTROL
8 CM/YEHR
15 CM/TEflR
23 CM/TEflR
M3 CM/TEflR
22 M4 6'6 88
PHOSPHORUS. PPM
1 0
. o
HII
1
•
a
CONTROL
7 CM/TERR
1M CM/TEBR
?0 CM/TERR
MI CM/TERR
in
25 50 75 100
PHOSPHORUS. PPrl
125
Fig. 3.
The Bray P-1 extractable P content of soil cores taken in the fall of 1970,
1971 and 1972 as affected by depth and average yearly application rate of
beef-feed lot-lagoon water.
-------
20
'id
100
FflLL 19.70
•ii
100-1—
150
Fig. 4,
CONTROL
8 CM/YEftR
17 CM/ TEBR
26 CM/YEflR
US CM/ YEHR
90 180 270360
EXTRflCTflBLE POTflSSIUM. PPM
FHLL 1972
FflLL 1971
5
BO
U50
100
B—Q CONTROL
» » 8 CM/TEflR
15 CM/TEflR
23 CM/TEflB
M3 CM/TERR
260uoso
P3TOSSIUM. PPM
800
1000
CONTROL
7 CM/TERR
14 CM/TERR
20 CM/TERR
Ml CM/TERR
300 1150 600
POTRSS1UM. PPM
750
900
Extractable K content of soil cores taken in the fall of 1970, 1971 and 1972 as
affected by depth and average yearly application rate of beef-feed lot-lagoon
water.
-------
FflLL 1970
CONTROL
8 CM/TEF>R
17 CM/TERR
26 CM/TEflR
-------
FflLL 1972
20-
40-
80-
100-
C0NTROL
7 CM/TERR
14 CM/TERR
20 CM/TERR
41 CM/TERR
0.0 0.5 1.0 1.5
E, C, MMHOS/CM
2.0
2.5
Fig. 6. The electrical conductivity of saturated paste extracts from soil cores taken
in the fall of 1972 as affected by depth and average yearly application rate
of beef-feed lot-lagoon water.
-------
. FflUL 1970
N)
10
o
8 16 24 32
LftGOON HflTER. flCC. CM
FflLL 1972
30 60 90 120
LRGOON WRTER. flCC. CM
150
60
FflLL 19.71
22 ' 44' 66 88
LflGOCN WflTER. flCC. CM
FflLL 1973
35 70 F5?" 140
LfiGOON WRTER. flCC. CM
no
175
Fig. 7. Corn forage yield (metric tons/hectare, corrected to 30/t dry matter) in 1970,
1971, 1972 and 1973 as affected by accumulative applications of beef-feedlot-
lagoon water.
-------
Kj
10
280-
250-
cr200-!
i
CD
iu'150-
Q_
ID
1 DO-
SO-
FflLL 1970
7 14 21 28
LRGOCM WRTER. RCC. CM
FflLL 1972
lo ' 60 ' 90 ' TaT"
LRGOON WflTER. flCC. CM
35
150
200
FflLL .19.71 .
22 44 66 88 110
LRGOON WflTER. RCC. CM
Fig. 8. Uptake of N by 1970, 1971 and 1972 corn forage as affected by accumulative
applications of beef-feed lot-lagoon water.
-------
FflLL 1970
FflLL .19.71
7 1'U 21 ' 28
LRGOON HRTER, RCC. CM
FflLL 1972
35
22 44 66 88 110
LRCOON WRTER, RCC. CM
DLT
0:45-
T:
0
GC
O_ J
0-15-
n.
X
xX
X
30 60 90
LRGOON WRTER. RCC. CM
150
Fig. 9, Uptake of P by 1970, 1971 and 1972 corn forage as affected by accumulative
applications of beef-feed lot-lagoon water.
-------
Nl
<0
300-
100
yoo-
FflLL 1970
7 14 21 28
LfiGOON WflTER. flCC. CM
FflLL 1972
35
30 6'0 9'0 120 150
LRGOON WflTER. flCC. CM
2140-
180-
-------
1200'
900-
Q_
O.
UJ
h—
-------
IRRIGATION OF TREES AND CROPS WITH SEWAGE STABILIZATION
POND EFFLUENT IN SOUTHERN MICHIGAN
by
Jeffrey C. Sutherland9, John H. Cooleyb, Daniel G. Nearyc
and Dean H. Urie
INTRODUCTION
The "living filter" concept of sewage wastewater treatment, docu-
mented extensively at The Pennsylvania State University', is being
tested in Michigan with systems designed both for research and prac-
tical solutions to immediate needs. Twenty to twenty-five rural
projects serving populations of under 1,000 to over 10,000 are now in
stages from preliminary to "in use". All of them involve initial
treatment through the secondary level in facultative Qonds, with or
without pretreatment in anerobic or aeration ponds ' .
Soil and vegetation renovation of wastewater in Michigan is a natural
extension of the wide use of outdoor ponds for sewage treatment in
rural communities which began around I960. Under orders to reduce
phosphorus in Great Lakes tributaries (beginning in 1968), many
Michigan communities are choosing irrigation over in-plant treatment
for reasons of economy.
The advantages of irrigation over other advanced treatment methods
are well known: assimilation of dissolved carbon, phosphorus,
nitrogen, micronutrients and filterables usually can be assured in
a single treatment step. No residues need be trucked away for dis-
posal. Increased farms yields are realized, especially in drouthy
areas, and new "ground water" is occasionally a valuable water
supply asset.
aHead geologist, Williams & Works, Inc.,. Grand Rapids, Michigan.
bPrincipal si Iviculturalist, North Central Forest Experiment Station
(U.S.D.A.), Cadillac, Michigan.
cGraduate research assistant, Forestry Department, Michigan State
University, East Lansing, Michigan.
Principal hydrologist, North Central Forest Experiment Station
(U.S.D.A.), Cadillac, Michigan.
Support of the studies was obtained through the United States Forest
Service (U.S.D.A.), The Michigan State University Institute of
Water Research, and Williams & Works, Inc.
295
-------
irrigation of woodlands is much less common than irrigation of farm
crops. Yet woodlands, in addition to being living filter systems,
have potentially great advantages: the Great Lakes region has a rela-
tively short growing season (5-1/2 months). But year around irrigation
of woodlands has been successful'. Public forest land often can be
acquired inexpensively, or free, while costs for farm land reasonably
close to service areas may be prohibitive. The expenses of annual
planting and frequent mowing would be avoided in areas where there is
no established agriculture to benefit from crop yields. Land too
rough to farm or develop is often left in timber. Such land could be
used economically for irrigation.
Isolation of residences from irrigation spray and, occasionally, from
visual contact with treatment sites, has been necessary in Michigan.
Woodlands can provide such isolation with a border zone tens of acres
smaller than would be needed in open farm areas. Irrigation of mature
stands can improve growth of understory vegetation, and thereby in-
crease food and shelter for ground birds, rabbits and deer4. Woodlands
on drouthy soils can absorb relatively high quantities of water with-
out fear of tree damage, with attending increases in rate of growth
being of potential benefit. In river lowlands and other wet areas,
drainage improvement as part of wastewater treatment design can make
or keep land suitable for tree irrigation programs. Irrigation and
management of immature ornamental and shade trees to be transplanted
to park, walkway and mall areas could be a practical adjunct of renew-
al and beaut ificat ion programs.
Since all economic indicators suggest demand for wood products will
grow faster than supply, increased markets for timber crops seem
assured.
Studies with young tree stock were started in lower Michigan to learn
how various species respond to irrigation on glacial soils common to
the Lake States region, and whether there are important differences
among species as to nutrient uptake. Experimental irrigation of es-
tablished tree stands was begun to study growth response, water quality
improvement and the effects upon existing ground water chemistry.
Studies at Middleville and Belding are the first in Michigan in which
sewage wastewater is being applied to trees in nursery and plantation
areas. The studies in progress at Belding involve irrigation of orna-
mental and shade trees. Data from one season of irrigation are avail-
able from Belding, but one or more years of further study are needed
for meaningful interpretations. In the Spring of 1974, irrigation of
Christmas trees, pulpwood species and northern hardwood trees with
pond stabilized wastewater will be started at Harbor Springs in the
Little Traverse Bay area.
The availability of irrigation facilities with adjacent woodlands and
areas that could be planted in trees determined the location of initial
experiments. Such a facility exists at Middleville, Michigan, about
32 kilometers (20 miles) southeast of Grand Rapids. The present paper
296
-------
discusses the results of two years of research at Middleville.
A sketch of the treatment area is shown in Figure 1. The Middleville
system (2,200 population) consists of two 4.4 ha facultative ponds
and II ha of farm land (corn) receiving chlorinated effluent. Two
experimental tree irrigation areas near the treatment site are receiv-
ing effluent from the south pond. The Middleville treatment system
was designed as an irrigation agricultural program.
NUTRIENT QUALITY OF STABILIZATION POND EFFLUENT
The average nutrient concentrations irrigated are listed in Table I.
Total phosphorus (total P) is less than 4 mg/I. Total nitrogen (total
N) is a little greater than 7 mg/l of which approximately 4.5 mg/l is
organic nitrogen (Org-N). The qualities changed between 1972 and 1973.
The nitrate nitrogen (NO-j-N): ammonia nitrogen (NH3-N) ratio of 0.2 in
1972 rose to 2.9 in 1973 and total P fell by 40 percent in the same
period. In 1972 the south pond received raw sewage directly. In 1973
the south pond received partially stabilized water from the north pond
and no raw sewage. This operation change accounts for the higher
NOj-N:NH3-N ratio. The reduction in total P is not easily explained.
Retention of phosphorus in sedimented organisms is a speculative pos-
sibility.
CORN
Corn (hybrid no. 4444) is planted and harvested by a local breeder
turkey farmer on 8.9 ha of the Middleville irrigation site. In making
turkey feed, the corn is dried and mixed with soybeans and other grains.
The corn field is mostly in Plainfield sand (Figure I) which is natu-
rally drouthy, infertile and easily moved by wind. Prior to the 1973
season, nitrogen rich fertilizer was added at II3 kg/ha rate. Irriga-
tion in May through July was intermittent, but in August and September
a 24-hour schedule was kept, which resulted in average applications
of 68 mm/week. Corn rows are spaced at 97 cm (38 in.) and individual
plants grow closely in a given row.
The results of irrigation were satisfying to the grower. Corn reached
heights of 2 m and higher within the wetted perimeter; beyond the
spray limits no corn exceeded 0.5 m in height. The yield on 8.9 ha
(22 acres) was 221 bu/ha (88.5 bu/acre) of dry shelled corn, or roughly
500 bu/ha (200 bu/acre) of ears.
Prior to the 1974 season, nitrogen fertilizer in twice the previous
amount will be app i ied to the f ields. Limi ng will be done in the wi n-
ter. The corn stover was plowed-in (October) in order to help build
the soiI.
The estimated value of the 1973 corn crop is $5,000, of which \5% to
2Q% is consumed in planting, harvesting, trucking and drying. Were
297
-------
TYPICAL
QUARTER CIRCLE
NURSERY
PLOT
LEGEND
GENERALIZED SOILS
Bellefontaine Sandy Loom
Fox Sandy Loam
Ploinfield Sand
* or Boyor Sandy Loom
-~l20m
\
STABILIZATION
POND /
4.4 ha
STABILIZATION
POND
4./4ho
\
\
=f=
1
AGRICULTURAL
IRRIGATION
AREA \
II ha
/THC
THORNAPPLE^
RIVER 500m
PS
\ Bs
\
J
Middle ville
RED PINE
IRRIGATION
AREAS
o°o o
o °
o
°°o£i
Figure I. Sewage Treatment Site
and Experimental Tree Study Areas,
MiddlevFIle, Michigan
298
-------
Table I
Irrigation and Water Quality Data by Year,
20-Year Old Red Pine Plantation,
Middlevi Ile, Michigan
Parameter
1972
973
Total
Waste
Water
Appl led
at ...
25 mm/wk
50 mm/wk
88 mm/wk
Average NH-j-N
Concentra- TKN
tion NO,-N
of Effluent Total N
(mg/l) Total P
Average
Load ing
Rate
(kg/ha)
1 rrigation
Season
25 mm
N 50 mm
88 mm
25 mm
P 50 mm
88 mm
Began
Duration
420 mm
820 mm
1350 mm
2.1
6.9
0.4
7.3
3.9
30.7
59.9
98.5
16.4
32.0
52.6
July 7
15 weeks
460 mm
920 mm
1610 mm
0.7
5. 1
2.0
7.1
2.3
29.8
65.3
1 14.3
10.6
21.2
37.0
May 24
*I8 weej<^
•cept for two weeks shutdown in July for repairs due to
ing damage.
299
-------
the community to manage such an operation, the net value of the crop
could pay for operation and maintenance of the ponds and irrigation
system.
TWENTY YEAR OLD RED PINE PLANTATION
A stand of red pine trees (Pinus resinosa) established in very well
drained sandy soils was irrigated during the 1972 and 1973 growing
seasons. Red pine is the most common plantation species in Michigan.
Information on red pine response to wastewater irrigation is available
from The Pennsylvania State University wastewater disposal studies5.
Following ten years of irrigation with secondary level effluent, red
pine receiving 2.5 cm per week exhibited increased height and diameter
growth over those of unirrigated trees. Trees receiving 5.0 cm per
week showed reduced growth. The growth reduction occurring at the
higher irrigation rate is believed due to the combination of boron
toxicity and excessive soil moisture. The red pine at Penn State grows
on loam soil of the Hublersburg-Hagerstown complex. Most red pine
stands In Michigan are on sandy textured soils of glacial origin having
little or no clay in the sub-soil and consequent low moisture holding
capacity.
Study Site
The Middleville trees grow on irregular land developed in gravelly mo-
raine. Soil is a typic hapludalf of the Boyer (Bellefontaine) series,
which is light colored, well drained sand and loamy sand overlying cal-
careous sand and gravel. Prior to red pine establishment, the land
had been farmed and then abandoned.
The plantation has an average spacing of 2.4 m. The average basal area
is 7.5 rrrVha and the average tree height is 11.6 m. The average DBH
(diameter at breast height) is 18.1 cm.
Procedures
Twelve circular areas of 7.5 m radius were selected for irrigation.
AlI trees were marked, pruned to a height of 2.4 m and measured for DBH.
The following four treatments were randomly assigned to three areas
each: (1) control - no irrigation; (2) 25 mm of effluent per week; (3)
51 mm of effluent per week; (4) 88 mm of effluent per week.
Water was applied during one 8-hour period each week by a single rotary
aerial sprinkler installed at the center of each area. The amount of
water applied varied predictably with distance from the sprinkler. The
4.9 m radius was selected as the point for soil water quality studies
since design rates of application were most nearly met here.
300
-------
Samples of sewage pond effluent were withdrawn from a tap on the irri-
gation line during spray periods. Soil water samples were removed from
60 cm and 120 cm depths using 51 mm diameter suction lysimeters. Vac-
uum was drawn on the samplers prior to irrigation and they were allowed
to fill during the ensuing 7 day period.
All samples were preserved with IN HgCI (I mg/100 ml). Analyses (total
Kjeldahl nitrogen — TKN, NH3~N, N03~N and total P) were conducted by
laboratories of the Institute of Water Research and Department of For-
estry at Michigan State University, using standard EPA methods^.
At the end of the growing seasons, needles from the second or third
whorls from the leader were sampled from four trees in each area for
nutrient analysis. Average needle length and dry weight per fascicle
were determined using 100 needle groups collected from the base of the
current season's shoot. The terminal bud of each branch used for nee-
dle samples was also measured. The DBH of each tree was recorded.
Tree heights were determined in 1973 for both years using five repre-
sentative trees per irrigation area.
Observations
The availability of percolating water at the 60 and 120 cm depths of
sampling was erratic. However, sampling was usually successful at 60
cm under all three irrigation rates. The samplers placed in control
plots captured so little water that only occasional analyses could be
made.
The average total N and total P concentrations were calculated from
mean monthly soil water data. Total monthly phosphorus values averaged
0.04 mg/l and less. Total N values were less than I mg/l, of which
NO,-N was 25 to 40 percent (Table 2). Higher total N concentrations in
the 1973 percolate than in 1972 relate to significantly heavier rain-
fall, hence dilution, during the 1972 season.
The extent of nutrient renovation of wastewater was determined by
weighting the concentration values by the volume of precipitation and
Irrigation in excess of the cumulative potential evapotransplration .
Nitrogen removal through the 60 cm depth was 83 to 92 percent, and
phosphorus uptake was in excess of 96 percent (Table 3). The renova-
tion figures show increased percentages of applied nitrogen passing
through the soils at heavier rates of irrigation. One probable reason
for this is that heavier applications promote more rapid percolation,
allowing less time for removal reactions. Levels of NH3-N in soil
water were essentially unchanged due to irrigation treatment. Nitrate-
N concentrations were significantly higher under the higher rates of
irrigation. Total N concentrations were also significantly higher
under heavier irrigation, largely due to the higher N03-N. Organic
forms of nitrogen accounted for approximately half of the total N.
Possibly the growth of algae in the suction soil samplers converted
307
-------
Table 2
Concentrations of N and P in soil water
at 60 cm depth (mg/l), 1973
Nutrient Parameter!/
Irri
Rate
gat ion
(mm/ week)
25
51
88
NH3-N
0. 10 a
0.20 a
0. 14 a
TKN
0.36 a
0.64 a
0.55 a
N03-N
0. 1 1 a
0.34 a
0.39 a
Total N
0.47 a
0.98 a
0.94 a
Total
0.02
0.04
0.03
1 P
a
a
a
not followed by the same letter are significantly different
at the 2.5$ level (paired student t test).
302
-------
Table 3a.
Renovation of N and P in effluent (1972)
Parameters
Ground
Water
Recharge
(mm)
Total
Nitrogen
(kg/ha)
Total
Phosphorus
(kg/ha)
Rate
25 mm
51 mm
88 mm
25 mm
51 mm
88 mm
25 mm
5! mm
88 mm
Jul.
0
0
51
0
0
0.3
0 <
0 <
0. 1
Renovation of
Parameters
Ground
Water
Recharge
(mm)
Total
Nitrogen
(kg/ha)
Tota I
Phosphorus
(kg/ha)
Rate
25 mm
5 1 mm
88 mm
25 mm
51 mm
88 mm
25 mm
51 mm
88 mm
Jun.
47
74
1 12
0.5
1 .6
1.6
O.I
O.I
<0. 1
Aug.
145
272
460
0.6
2.6
2.3
CO. 1
:o. i
0. 1
Tab
N and
Jul .
0
10
86
0
O.I
1.3
0
<0. 1
<0. 1
Sept.
79
202
356
0.2
0.8
1.8
<0.l
-------
NO-T-N to organic forms during the 7-day collection period.
The few successful field control samples (data not given) contained
total P similar to the irrigation plot samples, indicating that no
phosphorus above background levels penetrated to the subsoils.
The mean growth responses of red pine to the different irrigation rates
during the 1972 and 1973 growing seasons are presented in Tables 4 and
5. Needle lengths in 1972 averaged 144.9 mm, with no significant dif-
ferences due to irrigation rate. This was most likely the result of
the late start in the irrigation schedule (July 15) since 90 percent
of red pine growth normally occurs in June and early July^. In 1973
there were significant differences in needle growth which relate di-
rectly to the amount of water applied. Needle lengths increased 12,
28, and 36 percent over control areas with increasing irrigation levels,
going from 121.0 mm for the unirrigated trees to 164.4 for trees receiv-
ing the greatest irrigation. The decrease in needle length in the
control area trees from 1972 to 1973 is attributed to low rainfall in
June, 1973 (2.69 cm), compared to that of June, 1972 (11.05 cm) which
is close to the 30 year mean rainfall for June of 10 cm.
Terminal bud lengths exhibited no significant differences in 1972 which
could be related to irrigation. In 1973, trees receiving 25 mm had the
smallest terminal buds, but this is unrelated to the amount of irriga-
tion since no similar reduction was evident in the higher irrigation
rates. Branch terminal bud length thus proves not to be a sensitive
biological indicator of red pine response to irrigation. Measurement
of the terminal bud of the main stem might be a better indication of
irrigation response, but it is feasible only with small trees.
The growth trends in dry weight per fascicle parallel those of needle
length. No significant variations from the overall mean of 71.59 mg
per fascicle were evident in 1972. The 1973 data show that the needle
dry weight increased 8, 38, and 56 percent over the controls with the
application of 25, 51, and 88 mm of effluent. The significant differ-
ences occurred between the low and intermediate application rates.
Increases in both needle dry weight and length point to greater photo-
synthetic capability in trees irrigated at rates of 51 and 88 mm per
week than those receiving less irrigation.
The anticipated result of increase in total energy fixation would be
additional height and/or diameter growth. Table 6 lists the mean DBH
increment from 1972 to 1973 as calculated by measuring the parameter
for all trees in each plot. The average height and DBH data are in-
cluded for reference. No significant increase in DBH has yet appeared.
Any growth trends will show up in subsequent years as the 1973 needles
assume a larger role in photosynthesis. Needles normally remain alive
on trees for three years, contributing the most to photosynthesis in
the second and third years.
304
-------
Table 4
Mean Red Pine Growth Parameters for Varying Sewage
Effluent Irrigation Rates at Middleville, Michigan, 1972
Irrigation Rate
(mm/ week)
0.0
25
51
88
Needle Length
(mm)
142.6 al/
146.0 a
155.0 a
136.2 a
Termi na 1
Bud Length
(mm)
26.6 a
24.0 a
23.7 a
24.2 a
Dry Weight
Per Fascicle
(mg)
73.90 a
69. 17 a
81.12 a
62.18 a
j/Means not followed by the same letter are significantly
different at the 5% level (Tukey's test).
Table 5
Mean Red Pine Growth Parameters for Varying Sewage
Effluent Irrigation Rates at Middleville, Michigan, 1973
Irrigation Rate
(mm/ week)
0.0
25
51
88
Needle Length
(mm)
121.0 al/
136.4 b
154.9 c
164.4 c
.
Terminal
Bud Length
(mm)
28.3 a
24.5 b
27.9 a
30.2 a
Dry We ignt
Per Fascicle
(mg)
68.98 a
74.76 a
95.23 b
107.39 b
I/ Means not followed by the same letter are significantly
—' •.. ,, _i_ _j_ a.. t^cf io,,Qi fTnWf=\/'c; test).
different at the 5% level (Tukey's test)
305
-------
Table 6
1973 Red Pine DBH Increments and Representative Total DBH
and Height for the Sewage Effluent Irrigation Project
at Middleville, Michigan
rrigation Rate DBH Increment DBH Height
(mm/wk) (mm) (cm) (m)
0.0 3.99 ai/ 17.75 I 1.80
25 4.I I a 16.41 I I.83
51 4.67 a 18.39 12.77
88 4.09 a 16.46 12.77
— ' Means not followed by the same letter are significantly
different at the 5% level (Tukey's test).
The nutrient analysis of the foliage collected in 1972 indicated only
one significant variation between irrigated and unirrigated trees.
Only in the case of boron has a distinct irrigation rate response oc-
curred. Sopper and Kardos^ found boron levels of 23 and 33 micrograms/
gram (ug/g) in foliage from red pine irrigated at rates of 0 and 51 mm
per week, respectively. They reported no statistical significance to
the observed differences. Boron levels in the foliage from Middleville
specimens were 33, 28, 27 and 22 ug/g for the 88, 25, 51 and 0 mm rates,
respectively. The boron content of trees receiving 88 mm of effluent
per week is significantly higher than that of the unirrigated trees,
and high enough that occurrence of boron toxicity conditions in the
red pine is a distinct possibility. Should this condition continue
and toxicity symptoms result, red pine on well drained soil may have
to be eliminated from consideration as suitable for receiving treated
sewage wastewater, at least at levels approaching 88 mm per week.
CUTTINGS AND SEEDLINGS
Cuttings and seedlings were planted in soi Is of the Boyer series devel-
oped on a moraine of gravelly till composition. Some of the test plots
are positioned on slopes where erosion has removed much of the fine
material leaving a gravelly sand surface soil with little capacity to
retain moisture. Others are on areas where the fine material has been
deposited, resulting in a mantle of fine loamy sand which has a much
greater moisture retention capacity. Still others are on a temporary
305
-------
haul road or fill material which has been covered with roughly a foot
of very stony loamy sand. A compacted substratum severely restricts
percolation rate on these plots.
On the eroded slopes broad leaved weeds such as wild strawberry (Fragaria
vi rginiana) and hawkweed (Aurantiacum spp.) were major components of
existing vegetation but on the undisturbed flat areas there was a very
luxuriant growth of forage grasses, mainly brome grass, and scattered
low brush, mainly hoptree (Ptelea tri folfata). Clovers, fescues, and
brome grass seeded on the disturbed soils had become well established
before testing was begun.
Procedures
The tests included two hybrids of populus species, one an aspen type
hybrid (Populus canescens X I? gradi dentata) and one a cottonwood type
(Popu I us del toi des X P. nicjra); two species of larch, Japanese (Larix
leptolepi s) and European (L. deci dua); a hydrophytic conifer, northern
white cedar (Thuja occidentaI is); and three indigenous hardwood species,
tulip poplar (L_i_r i odendrcm t u I i p i f era) which at this latitude grows
naturally only on fertile, protected sites, northern red oak (Quercus
bo re a Ms) which grows on more exposed slopes and ridges, and green ash
(Fraxinus pennsyIvanica var. Ianceolata) which occurs on a wide variety
of sites but reaches best development on moist bottomlands. The two
populus hybrids were planted as rooted cuttings and the other species
as seedlings under 45.7 cm (18 inches) tall.
The cottonwood hybrid, green ash and white cedar were planted only on
the loamy sand with compact substratum; the other species were planted
on all soil conditions described. The plots were rototiI led thoroughly
before planting.
AI I except the cottonwood hybrid and red oak were assigned at random to
quarter circle plots of twenty-five trees each (Figure I). The white
cedar and green ash were planted in 12 quarter-circle plots; and the
larches, tulip poplar and aspen hybrid were planted in 9 such plots.
The cottonwood hybrid and red oak were planted in circles 8.8m from plot
centers. The cottonwood was planted in six circumferential plots, and
the red oak in nine.
After the first year (1972), surviving European larch were moved to
circular rows 1.5 and 2.7 m from plot centers and cuttings from the
cottonwood hybrid were planted in the quarter circle originally occu-
pied by the larch. Two cuttings were planted where each of the 25
larch had been. One was cut in February and held in cold storage for
three months and the other was cut just before planting.
At intervals throughout the first growing season weeds were cut and
the soil tilled. At the beginning of the second season (1973), dichlo-
benil (2, 6-dichlorobenzonitri le) was applied at the rate of 168 kg/ha
307
-------
to half of the area occupied by each species. The other half was
mowed often enough to keep weeds and grass from smothering the trees.
Effluent was applied through Rainbird 24A-23°FP-TNT sprinklers. A
single sprinkler was used for the low rate and two on a single riser
were used for the higher rate. The amount applied varied widely over
any one plot due to wind drift and from year-to-year due to malfunc-
tions in the distribution system. During the first year, the medial
total amounts were approximately 420 and 685 mm for the low and high
rates (46.6 and 76.2 mm/week, respectively). Irrigation did not be-
gin until June 23, was interrupted for three weeks in July because of
low water in the ponds and was terminated on September 7 to allow trees
to harden off before the first frost. During the second year 330 and
889 mm were applied in total (20.6 and 55.6 mm/week, respectively)
starting on May 17 and ending September 13. A two-week interruption
in August due to equipment failure coincided with an extended hot, dry
spelI.
Observations
Variations in weather during the planting period and differences in
effectiveness of weed control had a great deal of influence on survival
and growth during the first growing season. Also, there was an even
distribution of rainfall through most of the season which probably
minimized the effects of irrigation. Nevertheless, there were differ-
ences that seemed to be related to irrigation (Table 7). Height growth
of the aspen hybrid was only slightly better in plots irrigated at the
low level than in unirrigated plots, but it was one third better In
plots irrigated at the higher level. In contrast, the cottonwood hybrid
grew nearly 25 percent better at the lower level but only slightly
better at the higher level. Growth of other species was affected lit-
tle, If at all, by irrigation, but survival of Japanese larch, tulip
poplar, white cedar and red oak was improved. Survival of European
larch was poorest in plots that received the higher level of irrigation.
Growth during the second season provides a better indication of the
effects of Irrigation because most tree species were well established,
weed control was more uniform and there was an extended hot, dry
period (Table 8).
The rooting and survival of the new cottoqwood hybrid cuttings were
greater under lower level irrigation (15%) than in unirrigated areas
(4050 and under the higher level (68%} (Table 9). Possible development
of shallow root systems in the higher level areas followed by aggra-
vated moisture stress during the two weeks with neither rain nor irri-
gation could have caused the higher mortality. By the end of the
season surviving cuttings in irrigated plots were more than twice as
tall as those in unirrigated plots. The heavier irrigation increased
height growth little more than the lighter. Survival and height growth
of stored and fresh cuttings were about the same.
308
-------
Table 7
Survival and Growth of Cuttings and Seedlings
During the First Growing Season (1972)
Tree
Species
Cottonwood
hybrid
Aspen hybrid
Green ash
European larch
Japanese larch
Tul ip pop lar
White cedar
Red oak
1 rrigati
on Level
None Lower Hi
Survi
(f>
98
100
95
76
68
73
79
86
Height
val Growth
(cm)
50
42
30
12
12
5
5
1
Survi va 1
<*>
100
100
96
80
99
77
87
99
Height
Growth
(cm)
62
45
31
3
9
4
5
0
Survi va
<*>
100
100
100
65
88
83
91
94
qher
Height
1 Growth
(cm)
52
56
27
10
II
4
5
1
309
-------
Table 8
Survival and Growth of Cuttings and Seedlings
During the Second Growing Season (1973)
Tree
Species
Cotton wood
hybrid \J
Aspen hybrid
Green ash 2j
European larch
Japanese larch
Tu 1 i p pop 1 a r
White cedar \J
Red oak
None
Survival
(*>
100
97
100
54
94
52
86
100
1 rrigat
ion Level
Lower Hi
Height
Growth
(cm)
27
33
21
18
27
5
2
-1
Survival
(*>
100
99
98
76
92
75
94
83
Height
Growth
(cm)
101
60
38
17
38
22
10
-1
Survi va
(*>
100
100
95
79
89
80
86
95
cjher
Height
1 Growth
(cm)
1 12
69
36
28
26
21
II
-2
\J Difference in height growth between control and
treated plots is highly significant (\% level)
2/ Difference in height growth between control and
treated piots is significant (5% level)
Table 9
Survival and Growth of Cottonwood Hybrid Cuttings (1973)
Irrigation
Survival _[_/
Average
Height ]J
(cm)
None
Low I eve I
High level
40.0
74.7
68.0
33.3
70.0
74.9
\J Differences between control and treated plots are
significant (5% level)
370
-------
Contrary to first season results, irrigation improved survival of the
European larch that was replanted at the beginning of the second sea-
son (Table 8). The greatest improvement was in plots with compact
substratum. Ninety percent of the larch on unirrigated plots died
compared with 75 and 32 percent with the lower and higher levels of
irrigation, respectively. A similar pattern of mortality occurred !n
tulip poplar. Ninety-four percent of the unirrigated seedlings in
plots with compact substratum died, compared with 24 percent with lower
level irrigation and 20 percent with the higher level. The only unir-
rigated Japanese larch seedlings that died the second year had been
planted on the gravelly sand. No red oak planted in unirrigated plots
died even though there were some losses in irrigation plots. A few
green ash died, ail in irrigated plots, and there was slightly heavier
mortality in white cedar but it was not related to irrigation treat-
ments.
During the two week period with neither rain nor irrigation some mor-
tality occurred in all irrigated plots. Most of the mortality among
European larch and tulip poplar occurred in this time interval.
The irrigation effects on height growth of the two populus hybrids,
tulip poplar and white cedar, were dramatic. Irrigated white cedar
seedlings grew five times as much as those on unirrigated plots; irri-
gated cottonwood hybrids and tulip poplar grew about four times as
much; and irrigated aspen hybrids grew about twice as much.
Green ash grew rapidly in all plots, but irrigation increased its
growth about 80 percent. Irrigation had a similar effect on Japanese
larch growing on the loamy sand, and increased growth about 35 per-
cent in that growing on the graveliy sand. However, in the plots with
compact substratum the higher level of irrigation reduced growth by
85 percent and the lower level increased growth only slightly. Irri-
gated European larch on loamy sand increased in height more than five
times as much as in unirrigated plots but growth on gravelly sand was
inferior to that in unirrigated plots. The poor growth response of
larches under normally heavier irrigation in certain soils may result
from greater susceptibility to drought, as speculated above for the
cottonwood hybrid.
On the soil with compacted substratum, tips died back on many seedlings
that received no irrigation or low level irrigation, whereas most trees
grew a small amount where irrigation was heaviest. Many of the red
oak died back and height growth of the others was very siow. Irriga-
tion had no discernible effect on growth of this species.
Di scussion
It is evident from the early results of this study that survival and
initial growth of several tree species can be increased by irrigating
with stabilization pond effluent. The long term effects of irrigation
377
-------
are, of course, still to be explored. There is a distinct possibility
that heavy irrigation, expeciallyon poorly drained soils, will inhibit
development of the deep root system necessary to support large trees.
This could limit the size attainable in irrigated stands. There is
also a possibility that insect or disease problems will be aggravated
by irrigation. Diseases of root systems seem most likely to be aggra-
vated because of higher soil moisture. These are among the factors
that we hope to illuminate as we carry on additional studies including
other tree species, other soil types and other kinds of distribution
systems. In the near future we need to consider starting pilot tests
with some of the most promising species, such as the hybrid poplars,
so that we can find out more about the operational problems that may
be encountered when irrigating stands on a commercial scale.
SUMMARY
Corn in drouthy, infertile soil has shown excellent response to irri-
gation with stabilized sewage wastewater. The net value of the crop
at Middleville after farming, trucking and milling costs are subtracted
could support most or all of the sewage treatment site operation and
maintenance program.
The use of pond stabilized sewage wastewater for irrigation of hard-
wood and conifer plantings in southern Michigan has produced several
distinct results after two years of treatment. Water quality monitored
beneath a twenty year old red pine plantation has indicated 83-92 per-
cent renovation of nitrogen, and 96 percent removal of phosphorus.
Irrigation rates as high as 88 mm per week have resulted in an in-
creased flow of applied nitrogen through the soil-plant system.
Nitrate nitrogen levels have been significantly greater under irri-
gation rates of 50 and 88 mm per week than under 25 mm per week, but
have remained below 1.0 mg/l. Irrigated red pine has shown increases
in length and dry weight of needles by as much as 36 and 56 percent,
respectively, over that of unirrigated controls. At the present time
no trends in DBH increment or height growth have been observed. But
with continued increases in needle length and dry weight, increases
in DBH or height are anticipated. Nutrient analysis of the red pine
foliage has indicated elevated levels of boron which may lead to tox-
icity conditions in future years. No definitive statements on the
economic impact of wastewater irrigation of red pine are possible this
early in the project. If red pine volume growth increases in future
years, however, partial recovery of the irrigation cost should result.
The use of wastewater for the irrigation of hardwood cuttings and
seedlings has produced considerable increases in survival and height
growth. A cottonwood hybrid, an aspen hybrid, and green ash exhibited
the most dramatic responses to irrigation. These species grew an
average of 112, 69, and 36 cm, respectively, during 1973. Tulip poplar
and white cedar, while producing less total growth, increased their
growth by four and five times over the range of treatments. Irrigation
372
-------
produced moderate increases in height growth in European and Japanese
larch, and little effect on red oak.
REFERENCES
I. Parizek, R.R., Kardos, L.T., et_ aj_. Wastewater Renovation and
Conservation. The Pennsylvania State University Studies No. 23,
1967,71 p.
2. Williams, T.C. Utilization of Spray Irrigation for Waste Disposal
in Small Residential Developments. Proceedings of the Symposium
on Recycling Treated Municipal Wastewater and Sludge Through
Forest and Crop Land, Wm. E. Sopper and L.T. Kardos, eds. The
Penn State University Press, 1973, pp. 385-395.
3. Urie, Dean H. Opportunities and Plans for Sewage Renovation on
Forest and Wildlands in Michigan. Michigan Academician. IV (I):
I 15-124, 1971.
4. Wood, Gene W., Simpson, D.W., and R.L. Dressier. Effects of Spray
Irrigation of Forests with Chlorinated Sewage Effluent on Deer
and Rabbits. Proceedings of the Symposium on Recycling Treated
Municipal Wastewater and Sludge Through Forest and Crop Land,
Wm. E. Sopper and L.T. Kardos, eds. The Penn State University
Press, 1973, pp. 311-323.
5. Sopper, Wm. E., and Louis T. Kardos. Vegetation Responses to
Irrigation with Treated Municipal Wastewater. Proceedings of the
Symposium on Recycling Treated Municipal Wastewater and Sludge
Through Forest and Crop Land, Wm. E. Sopper and L.T. Kardos, eds.
The Penn State University Press, 1973, pp. 271-294.
6. Standard Methods for the Examination of Water and Wastewater, 13th
Edition. APHA, AWWA, WPCF. 1971.
7. Thornthwaite, C.W., and J.R. Mather. Instructions and Table for
Computing Potential Evapotranspiration and the Water Balance.
J_0(3): 184-311, 1973. DrexeI Inst. of Technology, Publications
i n CIimatology.
8. Neary, D., Day, M. and G. Schneider. Density-Growth Relationships
in a Nine Year Old Red Pine Plantation. Michigan Academician.
V (2) : 219-232, 1972.
313
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USES OF POWER PLANT DISCHARGE WATER IN GREENHOUSE PRODUCTION^
B. J. BondXw. K. Furlong,3/!. D. Si
C. E. Madewe 11,27 j. 3. Martini/
INTRODUCTION
AVAILABILITY OF WASTE HEAT FROM POWER PLANTS
By the term "waste" heat^we mean energy which is so degraded in tem-
perature that its economic uses are, historically, limited. Usually
it has been considered practical only to discharge this energy
directly to the environment. Typically, such energy appears in the
large quantities of cooling water necessary to condense the steam in
power generation facilities. For example, a 1000 mW fossil-fired
plant with a 20° F. rise through the condenser and a 7 percent stack
loss discharges slightly over 1000 cubic feet per second of warm
water. Such cooling water generally is discharged in the range of 60
to 110 F., depending on the temperature of the available inlet water,
the quantity circulated, plant load, and the use (if any) of supple-
mentary cooling devices. For instance, at the TVA Browns Ferry nuclear
plant, condenser water discharge is calculated to vary from a low of
70 F. in January/to 110° F. in July and August, for 100 percent once-
through cooling.* If cooling towers, either evaporative or dry, are
used for part or all of the heat rejection, then the temperature of
the water increases significantly. For evaporative towers, condenser
water temperature would range from 75 to 125° F., depending upon the
time of year and location. At Brogns Ferry, predicted condenser dis-
charge temperatures range from 110 F. in January to 12.U F. in July
and August, if all of the heat were to be rejected by evaporative
cooling towers. For dry cooling towers, the water temperature would
be 20-M) F. higher than temperature with once-through cooling.
^Research sponsored jointly by the TVA's Divisions of Agricultural
Development and Power Resource Planning and by the U.S. Atomic Energy
Commiesion under contract with the Union Carbide Corporation.
^Division of Agricultural Development, Tennessee Valley Authority,
Muscle Shoals, Alabama
Ridge National laboratory, Oak Ridge, Tennessee
example is for illustration only and is not meant to imply
that TVA will permit the discharge of water as hot as 110 F. directly
to natural bodies of water.
314
-------
The annual quantity of waste heat presently available in the U.S. is
staggering—on the order of 101 Btu, equivalent to 1.6 billion barrels
of fuel oil. It is projected that by 1980 TVA's coal-fired and nuclear
power plants will be generating waste heat at an annual rate of lO1^
Btu.
TVA is concerned with developing all the resources in the Tennessee
Valley region. Consequently, for several years we have been looking
at methods of using some of this tremendous quantity of waste heat as
a resource. Several projects under way are: catfish production in
raceways using condenser cooling water, soil heating to extend the
growing season of horticultural and field crops, and the use of con-
denser cooling water for environmental control in greenhouses. Waste
heat will also be used in a system we are developing to biologically
recycle nutrients in livestock waste.' '^ Suggested uses and actual
projects by other organizations are numerous.%>?>®>> it is doubtful
that proposed systems can use more than a small fraction of the energy
discharged from power plants. Nevertheless, if we could find an
economic use for only 10 percent of the heat rejected from all gener-
ating stations projected to be built between now and the year 2000,
the utilization would be about the same as all the electrical energy
sold in 1972 (1.85 x KX mW-hr).
PILOT GREENHOUSE
The TVA waste heat research greenhouse at Muscle Shoals, Alabama, is
the result of the cooperative efforts of many individuals. Engineers
at Oak Ridgp National Laboratory (ORNL) developed the basic environ-
mental control system for the greenhouse. They, in turn, provided
technical assistance to TVA engineers (Division of Chemical Development
who designed the actual facility. Funds for construction of the
greenhouse were provided by the Division of Power Resource Planning.
The Division of Agricultural Development coordinates the project and
operates the greenhouse.
The three major overall objectives of the research project are to test
the capabilities of the environmental control system, to determine the
effect of the resulting environment on production of horticultural
crops, and to evaluate the overall economics of the system. Results
of engineering and horticultural tests and economic analyses will be
used to refine the system. If the resulting system proves viable,
there are tentative plans to build a facility of approximately one acre
at Browns Ferry nuclear power plant in north Alabama where TVA has
reserved l80 acres inside the exclusion area for possible waste heat
use.
Specific engineering and horticultural objectives are:
Engineering Objectives
1. To obtain controlled-environment data over the entire spectrum of
yearly operating conditions,
375
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2. To determine the response of the greenhouse to changes initiated
by a relatively sophisticated control system as well as changes
from external perturbations,
J. To study the effect of the presence of crops on the performance
of the environmental control system (heating, cooling, and
dehumidification),
k. To have an empirical check for our analytical models for green-
house design and to improve those models, and
5. At a future date, to study alternate means of greenhouse environ-
mental .conditioning.
Horticultural Objectives
1. To obtain quantitative data on the yield of various crops,
2, To study crop performance, including the incidence and control
of disease, under high relative humidity (95-100 percent)
conditions,
3. To study hydroponics versus growth in rooting media, and
k. To determine the effect of root media heating on crop performance.
DESIGN
SUMMARY
The greenhouse, shown schematically in Fig. 1, is a conventional
aluminum-framed glass-glazed structure. The simulation of waste heat
is from an electric water heater (boiler). Cooling is by evaporation
from aspen fiber pads through which air is circulated by two prope Hep-
type fans. Air can be recirculated through an attic plenum or dis-
charged directly outdoors. The air flow is controlled by automati-
cally-adjusted louvers. Heating is by sensible heat transfer from
warm water flowing over the aspen fiber pads to recirculated air at
saturation. Dehumidification can be provided by a bank of fin-tube
heaters supplied with warm water.
FUNCTIONAL BEQUffiEMENTS
In view of the objectives stated above, several functional requirements
were identified at the start of the design and served as guides for
all subsequent design work. These requirements will be discussed
belov.
Flexibility
Because of the research nature of the greenhouse, operational
flexibility was paramount in all decisions pertaining to the heating,
cooling, control and structural components and systems. This means
that we tried to provide for operation where a given variable (e.g.
air flow rate) departed considerably from the traditional or expected
range of variation. In all cases, flexibility was deemed more impor-
tant than minimal cost.
316
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Intake
Shutters
/ i
/
v|f
^^^
\
^2^^^^*H^
^^^
>^
v^
Aspen
Pad
V
1
V \ ~ 1
T r
Sump
i
x
w
^-
^-i
00
oo
00
00
00
00
00
oo
oo
00
oo
00
00
00
oo
oo
00
00
oo
00
00
oo
oo
Fin
^r-
Recirculation
Shutters
// V \ \ N
i
Tube
Heater
J
'
t
Pump
_/_
LV
^^L
-t
Water
Heater
1 Diverter Valve
\ \ \ \
A
T
^ V
8\
!U* x
"s-
Growing
Area
j ./
V
/ ^
Exhaust/
Shutters
Figure 1. Waste Heat Research Greenhouse, Muscle Shoals, Alabama.
-------
Major Variables
The operating variables which bear on the engineering design are
summarized below, along with the design values for the range of each
variable. /
1. External ambient dry bulb temperature: 16-91 F.
2. External ambient relative humidity: 40-100 percent
3. Air flow rate: 11,000-36,000 cfm
k. Air exchange rate in crop region: 1-2 volumes/min.
5. Warm water flow rate: 0-100 gpm
6. Makeup water flow rate: 0-2 gpm
7. Power required for warm water source: 0-l80 kW
8. Maximum relative humidity in crop region: 80-100 percent
9. Warm water inlet temperature: 70-124° F.
10. Minimum air temperature over crops: 55-60 F.
11. Maximum transmitted solar flux: 278 Btu/hr./sq.. ft.
Humidity Reduction
Humidity reduction was considered a third functional requirement. This
may turn out to be unnecessary, if humidity-resistant strains can be
developed and disease control maintained. For example, operation
close to 100 percent relative humidity has been successful at the
University of Arizona Puerto Penasco Project-'. Nevertheless, because
of the research nature of our greenhouse and in the interest of
flexibility, provision was made in the design for reducing relative
humidity below 100 percent when operating with recirculated air or
in the presence of high ambient humidity.
Data Sensing and Recording
Greenhouse temperatures, humidity, water flow rates and temperatures,
external ambient conditions, fan speed, and louver bank position were
selected as the major data which required detection and continuous
recording.
Other Considerations.
We recognize that use of warm water to heat the root zones (and, to
whatever extent possible, the greenhouse air itself), constitutes a
highly desirable future experiment. In addition, we desired to use
one side of the greenhouse for hydroponics while the other employed
rooting media. Another requirement was the provision for partial or
i Q
^-^Phe ASHRAE design guidelines (for air conditioning) indicate
that 5^ hours per year will be below 17° F. and 150 hours will be
above 9^ F. at the greenhouse location.
318
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complete recirculation of air back to the pads under ambient conditins
where warm air must be conserved. These considerations were identified
early so that the design would reflect any special requirements.
The detailed design proceeded after establishing the functional
requirements discussed above. The sections which follow summarize
the detailed design.
COOLING
Evaporation was the only type of cooling considered for the greenhousa
In this sense, the greenhouse becomes a small horizontal cooling tower
when coupled to a power plant, regardless of the presence or absence
of crops. The use of a bank of aspen pads approximately 23 ft. x 7 ft.
x 2 in. thick follows conventional greenhouse practice. This instal-
lation is shown schematically in Fig. 1. We expect to experiment with
other pad arrangements and materials in the future in an effort to
improve the cooling. An important contribution to improved cooling is
increased air flow through the greenhouse. This not only reduces the
air>4T through the house, due to the solar load, but also increases
the heat and mass transfer coefficients in the pads themselves. The
latter vary directly with the face velocity according to'ORNL
experiments. Our fans are capable of producing two air changes per
minute in the growing space. This is equivalent to a face velocity
at the pads of about 250 ft./min.
HEATING AM) DEHUMDIFICATION
Due to the relatively low temperature water available, it was decided
that a contact type heat exchanger would be required to supply the
major portion of heat to the greenhouse. We chose to try to use the
simple, inexpensive pads as contact heat-exchange surfaces for heating
the greenhouse with simulated waste warm water. (Several other heating
methods are available, such as sprays, underground pipes, compact fin-
tube radiators, and even heat pumps. These alternate methods will not
be discussed in this paper.)
Two precedents existed for the direct-contact heating—the experience
at Puerto Penasco by the University of Arizona researchers and our own
experience at ORNL with a small test greenhouse.
One feature of the direct-contact mode of heating is that the air
quickly reaches saturation and remains near that condition as it is
recirculated back through the pads and the greenhouse. To permit
dehumidification, we installed a bank of fin-tube heaters about 5 ft.
downstream of the pads (Fig. l). This heater bank is spread out to
cover the entire flow area. Each tube is about 20 ft. long, headered
at each end to form two circuits of four passes each to provide even
temperature distribution. The fin-tube bank can be operated with warm
water either in series or in parallel with the pads, as shown in Fig.L
319
-------
It is designed to lower the relative humidity from 100 percent to 80
percent by providing TO kW. One-inch copper tubing is used with
aluminum fins. Air pressure drop across the surface is negligible.
Water at waste heat temperatures for the pads and fin-tube heater is
provided "by a standard commercial l80 kW hot water heater.
Heating of the plant root zones is accomplished by diverting warm
water from the system just downstream of the hot water heater. This
water flows through coils of 3/U inch FVC pipe buried 8 in. below the
surface of two rooting media (soil and pine bark/vermiculite mix).
The water is discharged to the pump suction basin.
CONTROL AND INSTRUMENTATION SYSTEM
The control system is designed to maintain a preset air temperatureana.
a preset relative humidity with a given fixed supply water temperature.
Air temperature is controlled by changing fan speed and by modulating
the amount of air that is recirculated through the house. The possible
air flow modes are: once-through, and 25 percent, 50 percent, 75 per-
cent and 100 percent recirculation. Control is achieved by individual^
opening or closing each of four banks of louvers on the inlet, outlet,
and recirculation flow paths. Five thermistors in the greenhouse
supply temperature signals; control can be from any one or combination
of the five.
Relative humidity control is effected by diverting warm water through
the fin-tube heater. A diverter valve (Fig. l) modulates the flow in
response to a signal from two gold-grid humidity detectors in the
growing space.
Instrumentation for the greenhouse consists of detectors for flow,
temperature, and humidity signals plus appropriate readout and, in
some cases, recording equipment.
The warm water supply temperature is preset on the water heater. Water
temperature is measured by thermocouples at six locations: upstream
of the water heater, downstream of the mixing valve, outlet of the
fin-tube heater, pad inlet and outlet, and makeup water inlet. These
values are recorded on a multi-channel strip recorder. Ambient air
temperature and five internal greenhouse temperatures are measured by
thermistors and similarly recorded. Five portable recording hygrom-
eters have been used initially for both wet and dry bulb data, but
they will not be retained for long-term operation.
Relative humidity is measured by two separate gold-grid detectors
mounted in aspirated cabinets at the entrance and exit of the growing
space. These signals are fed to a controller which has a provision
for recording, but they are not recorded at present. A visual
indication is provided on the control panel, however.
320
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Fan speed and louver position have visual indicators on the control
panel and are also recorded on a strip-chart device. The TVA weather
station at Muscle Shoals can provide hourly summaries of wind speed
and direction, dry bulb and dew point, barometric pressure, and, most
significantly, solar and total radiant flux. We expect to utilize muh
of these data in lieu of duplicating the same measurements ourselves.
INITIAL ENGINEERING TESTS AND RESULTS
One design error had to be rectified: the attic barrier, originally
4-mil polyethylene, was replaced with corrugated fiber glass-rein-
forced acrylic panels. Over a period of about 8 months, the poly-
ethylene had become severely embrittled and weakened by the combinatai
of solar radiation and heat in the attic. Also, an exhaust fan may be
installed for the attic, to operate when the main fans are in the
once-through mode (summer cooling).
TESTS
In general, our engineering tests sought to measure:
1. Air flow rate, both fast and slow speed, with once-through flow
and with partial and full recirculation. These data were taken
with a hot-wire anemometer using a 12-point grid set up to
represent equal flow areas per point.
2. Fan performance, such as speed, head, flow and power requirement,
3« Pressure drops, especially for the pads, fin-tube heater, and atti^
h. Air temperature and humidity at various locations and under various
operating conditions,
5. Control system performance, such as the maintenance of preset
temperature or humidity,
6. Water temperature as controlled by the water heater, and
T. Pad and fin-tube performance, as measured by water temperatures
and air enthalpies.
RESULTS
Our engineering tests are not complete as yet, but a summary of
qualitative results is presented below. (Items 1, 2, 3 and 8 apply to
an empty greenhouse. The others apply to-a house with a mature
cucumber crop-)
1. Air flow decreases as the fraction recirculated increases, with
80 percent of the once-through flow obtained under full recircu-
lation. This applies to either fan speed.
2. There is considerable variation in air velocity with location in
the plane perpendicular to flow. Flow decreases as elevation
increases, with a change as much as 50 percent in some locations.
3. The water heater, with its 10-step controller, maintains water
temperature within j£° F. of the setpoint. o
h. The greenhouse air temperature ranged between 65 and 68 F. for a
clear night where the ambient reached a 19 F. while operating
with water at 7*4- F. The fin-tube heater supplied about 20-30
327
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percent of the heat under these conditions.
5. Data taken over sevenQdays in early December, with ambients
ranging from 19 to 35 F. indicated air temperatures 7 to 11° P.
lower than vater inlet temperatures to the pad. (The fin-tube
heater was supplying about 20-30 percent of the total heat during
this period.)
6. The coldest night tQ date, 13 F., produced a 63 F. house
temperature with T^ F. water. The fin-tube heater supplied about
20-30 percent of the heat.
7. We have calculated that 95-100 kW of heat was used when the ambient
temperature reached 19 F. This is in good agreement with the
design value of 111 kW at 16° C,
8. Greenhouse cooling was checked at two extremes of water tempera-
ture, 6£> F. and 119 F. In the former case, the water was
recirculated and the pad inlet and outlet temperatures were the
same as the ambient wet-bulb 66° F. The switch to high-tempera-
ture water brought the pad outlet up to 73 F* In both cases,
the ambient air was cooled, by 6° F. with 66 F. supply water and
by U F. with the 119 F. water. Further cooling data must await
spring and summer operation.
9. The heating system is highly buffered against changes in outside
temperature as evidenced in Fig. 2. A change of 31 F. outside
resulted in only a 5° F. change inside.
INITIAL HORTICULTURAL TESTS AND RESULTS
We are testing tomatoes, cucumbers and lettuce in the greenhouse.
These three crops were chosen because they occupy about 93 percent of
the greenhouse area devoted to vegetable production in the United
States. In one experiment, rooting media are being tested: heated and
unheated soil (Ochlockonee fine sandy loam), heated and unheated pine
bark/vermiculite mix, and wheat straw bales (cucumbers only). The
pine bark/vermiculite mix is a variation of the peat moss/vermiculite
mix conanonly used for greenhouse tomatoes. The straw bale culture is
a technique commonly used in Europe and England for greenhouse
cucumber production. All media treatments received fertilizer
according to the schedule in Table 1.
322
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70
1
•I 66
& 64
o»
62
o>
o>
60
10
Water Temperature, 73°F
Pad flow 2.5 gpm/ft
Fin tube flow 40 gpm
20 30
Outside Temperature
40
so
Figure 2. Response of greenhouse temperature to outside temperature changes.
-------
Table 1. Fertilizer Schedule*/for Rooting Media
(NH4)2HP04 mpO^ TO^Ca(N03)2 MNO"
grams/100 liter
1
2--3
4-10
11-12
13-17
134
67
67
134
134
134
67
67
0
0
0
0
134
268
268
0
0
268
268
268
0
0
134
134
268
In a separate experiment, two hydroponic systems are being compared.
One system consists of gravel-filled troughs which are periodically
pumped full of nutrient solution and then allowed to drain. They are
filled four times per day during clear weather and fewer times during
cloudy periods. The other system consists of troughs of coarse sand
to which nutrient solution is surface applied daily. Both systems
use the nutrient solution shown in Table 2.
Table 2. Nutrient Solution Used in the Hydroponic Systems
Element Concentration
ppm
N
P
K
Ca
Mg
S
Mn
Cu
Mo
Zn
Fe
01
B
135 (increased to 200 after first fruit
62
156
165 (increased to 230 after first fruit
49
64
0.62
0.05
0.03
0.09
5.00
0.86
0.44
set)
set)
324
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Femfrance cucumbers were transplanted into the greenhouse on October
10 at a population density of one plant per 8 ft. of greenhouse area.
Femfrance is a long, seedless cucumber developed especially for
greenhouse production. Yields for the entire harvest period are
shown in Table 3-
There was no significant effect of media heating on yield. This is
because soil and mix temperatures have been at an acceptable levelQto
date. For examgle, on December 3 with 8h° F. water, the mix was 7^ F«
unheated and 82 F. heated. Respective values for soil were jk F. and
ar F.
There was no significant effect of media on total or grade no. 2 yield.
However, yields of grade no. 1 cucumbers in bale culture were less than
yields in soil or artificial mix. Also, the unheated soil was
superior to artificial mix in number of grade no. 1 cucumbers produced.
Hydroponic yields cannot be statistically compared to the other yields.
Significantly fewer grade no. 2 cucumbers were produced in the sand
culture as compared to the gravel culture. Type of hydroponic system
had no effect in the other two yield categories.
Grand Rapids leaf lettuce and Bibb lettuce were transplanted into the
greenhouse on November 15. The hydroponic systems and the heated and
unheated soil and mix used were identical to those used for cucumber
production. In late January, cucumbers were replanted and the
lettuce replaced with tomatoes.
During November, the greenhouse was operated without humidity control
for IT days; i.e., the fin-tube heater was inoperative. During this
period of high humidity (95 to 100 percent relative humidity), there
was an outbreak of powdery mildew (Erysiphe cichoracearum). A
reduction in humidity to about 85 percent by activating the fin-tube
heater and a change from zineb fungicide to benlate checked the fungal
outbreak. It is probable that simply the use of benlate would have
had the same result.
Since Femfrance cucumbers are different in appearance and taste from
cucumbers available in stores in the Muscle Shoals area, a consumer
acceptance test was conducted at a local supermarket. Results are
given in Table U. The Femfrance cucumbers were well accepted and sold
for about twice the price of the field variety.
325
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Table _3_
Cucumber Yield, Nov. 8-Jan. 30.
Cu
Soil
(1)
(2)
(3)
Total yield: Ibs. /plant
Cucumbers/plant
Grade no. 1 yield:
Ibs. /plant
Cucumbers/plant
Average weight, Ibs.
Grade no. 2 yield:
Ibs. /plant
Cucumbers/plant
Average weight, Ibs.
Unheated
19 .k
16.1
/
15. 60?
12. 5a
1.25
3.4
3.2
1.10
Heated
18.2
15. 5a
12.3ab
1.26
2.6
2.U
1.10
Pine Bark
Verraiculite Mix
Unheated
18. U
lU.o
13. 6a
9.9c
1.37
3.6
2.9
1.26
Heated
19.1
1U.7
13. 9a
10.3bc
1.35
U.7
3-9
1.21
Straw
Bales
1U.1
11.7
8.6b
6.6d
1.30
k.2
3-7
1.13
Hydroponic
grave 1
21.2
18.0
16.8
13-7
1.23
3-9a
3-7a
1.0
sand
22.3
19-5
20.1
17-3
1.16
2.2b
2.2b
1.0
^Values followed by the same letter are not significantly different at the 5 percent level of
probability. Hydroponic yields cannot be statistically compared with yields from other treatments.
-------
Table U. Market Test, Nov. jO-Jan. i8
Price
Femfrance
Field Variety
Range
- _ _
.25-..U9
.15-. 29
Mean
$ - - -
.38
.20
Number
Sold
U06
1013
ECONOMIC IMPLICATIONS
Results of an initial economic evaluation stress the need for refine-
ments in greenhouse design to make it show greater economic potential.
One example would be to recirculate the air through an adjacent house
and thus, eliminate the fiber glass ceiling presently used to form
the recirculation attic. Also, if power plants go to closed-loop
cooling, the higher temperature water available will lower capital and
operating cost. For example, lower water flow rates or smaller heat
exchangers would be required. Also, cost of disease control would be
reduced if lower humidity could be maintained with the warmer water.
Of course, many factors which would improve production and sales in a
conventional greenhouse would also be important in improving the
economic potential of waste heat greenhouses. These factors would
include improved crop varieties, batter and cheaper disease and insect
control, improved labor efficiency, and the increasing demand for off-
season, greenhouse grown products.
IN CONCLUSION
We are pleased with the engineering system because it has performed
as designed to date. However, we do plan modifications to the
present house to test variation on the central theme of heating and
cooling with a single contacting device (pads)' Similarly,
horticultural production has been satisfactory to date but we will
continue screening crops, varieties, and rooting media to increase
production.
An important future question which we intend to examine is that of the
interface between a large greenhouse installation and a power plant.
Of interest are such things as variation of water temperature wi^Ii
load, plant shutdown, water quality and activity monitoring, greenhouse
revenue and rate structure, legal liability to commercial lessees, etc.
In addition, many questions remain regarding crop marketing and
operational economics.
We believe that this pilot facility, although still in the early
stages of operation, will continue to provide us with good engineering
guidelines for the design of a larger demonstration facility to be
327
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located at an operating power plant, and we 3ook forward to initiating
conceptual design work on such an installation.
328
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References
1. Williams, G. G., "TVA Programs-Waste Heat Utilization in
Greenhouses and Other Agriculturally Related Projects."
Proceedings of the National Conference on Waste Heat Utilization,
October 27-29, 1971, Gatlinburg, Tennessee. CONF-TllOJl
(May 1972).
2. Bond, B0 J., C. E. Madewell, J. B. Martin, Jr., and D. A. Mays.
"TVA Projects—Beneficial Uses of Waste Heat." Proceedings of
the National Conference on Complete WateReuse, Washington, B.C.,
April 2J-27, 1973-
3. Madewell, C. E., J. B. Martin, and B. G. Isom, "Environmental and
Economic Aspects of Recycling Livestock Wastes—Algae Production
Using Waste Products," paper presented at the Association of
Southern Agricultural Workers meeting January 31-February 3, 1971,
Jacksonville, Florida.
h. Yarosh, M0 M., e_t al. "Agricultural and Aquacultural Uses of
Waste Heat," USAEC REPORT ORNL-1+797 (July 1972).
5. Yarosh, M. M., and B. L. Nicholas (Oak Ridge National Laboratory),
"Waste Heat and How It Might Be Used," "The Potential for
Agricultural and Aquacultural Uses of Waste Heat," and "Factors
That Need to be Considered in Utilizing Waste Heat," (Published
in AWARE Magazine) Reprints available from: AWARE Magazine,
615 North Sherman Avenue, Madison, Wisconsin 5570^- Price
each.
6. Beall, S. E., and G. Samuels, "The Use of Warm Water for Heating
and Cooling Plant and Animal Enclosures," USAEC Report ORNL-TM-
3381 (June 1971).
7. Symposium: Beneficial Uses for Thermal Discharges, Journal of
Environmental Quality 2:178-228, Apr.-June 1973-
8. American Society of Heating, Refrigeration, and Air Conditioning
Engineers, "Handbook of Fundamentals," 1967 ed., Chapter 22.
9. Jensen, M. H., "The Use of Waste Heat in Agriculture," Proceedings
of the National Conference on Waste Heat Utilization, October
27-29, 1971, Gatlinburg, Tennessee, CONF-711031 (May 1972).
10. Furlong, W. K., M. I. Lundin, L. V. Wilson, and M. M. Yarosh,
"Activities Report—Beneficial Uses of Waste Heat Covering ORNL
Activities Through December 31, 1972, in the Joint AEC(ORNL)-TVA
Program," ORNL-TM-la95 (June 1973)-
329
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PART 5 NONTECHNICA L RES TRAI NTS
SESSION CHAIRMAN
JOHN H. MARSH, P.E.
PRESIDENT, ENGINEERING ENTERPRISES
NORMAN, OKLAHOMA
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LEGAL CONSTRAINTS ON THE USE OF WASTEWATER
FOR FOOD AND FIBER
by
William R. Walker and William E. Cox*
INTRODUCTION
The world demand for increased production of food and fiber places
an ever increasing strain on the available water supply. The problem
is accentuated by the current energy crisis, which is not likely to
be of short term duration. Prior estimates of water demands may
well be grossly underestimated when one contemplates the consumptive
use of water in energy production (e.g., coal-gasification) and for
irrigated agriculture. Effective management of our wastewater re-
sources moves from something which is highly desirable to something
which is absolutely essential.
The recycling of municipal sludges and effluents on land has been
used more extensively in other parts of the world than it has in the
continental United States; therefore, this alternative for waste dis-
posal has not had an in-depth evaluation in the United States
relative to other methods. Increased interest in recent years has
stimulated additional research into the health aspects of this method
of disposal (e.g., survival of viruses) and the direct effect on food
and fiber production. No assessment of this waste management tech-
nique can be complete, however, without some discussion of the
institutional processes by or through which this waste management
scheme functions. Although these institutional considerations in-
clude such diverse matters as the form and powers of water organiza-
tions, financial arrangements, public attitudes, and political
traditions, this paper will concentrate on legal aspects as manifest
in legislative enactments and the common law. It will first examine
direct government control over this disposal technique by the federal
and state levels of government. Second, since relatively large areas
of land are an indispensable component in this method of wastewater
treatment, governmental regulation of land use must be examined along
with the corollary common law rights of other property owners in the
same area. Third, both statutory and common law rights related to
water must be fully analyzed in terms of this method of disposal
since land application of wastewater alters the flow regimens of both
surface and ground water.
*Director and Research Associate, respectively, Virginia Water
Resources Research Center, Virginia Polytechnic Institute and
State University, Blacksburg, Va.
330
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DIRECT GOVERNMENT CONTROLS
FEDERAL
The federal government has historically left the jurisdiction of
water pollution control in the province of state and local govern-
ment, viewing it essentially as a public health matter to be dealt
with under the police powers. The first comprehensive federal -,
control effort was the passage of the Water Pollution Control Act
in 1948. This legislation relegated the federal government to a
"back-up" position with primary responsibility for pollution control
to remain in the hands of the states. The Federal Water Pollution
Control Act of 1956^ contained the first authorization of federal
grants on a large scale to assist states and municipalities in plan-
ning and building facilities for treatment of wastewaters. The Act
contained prohibitions and omissions that were not encouraging to
the land treatment method. For example, the cost of land for sewage
treatment, including use of land as an integral part of wastewater
processing, was not eligible for grant assistance, and no provisions
were made for grants in connection with recycling and reclamation of
wastewater.
On October 18, 1972, the Federal Water Pollution Control Act Amend-
ments of 19723 became law. This Act is without question the most
comprehensive and complex legislation that has ever been enacted to
clean up the nation's waters. It establishes a national policy that
a major effort be made to develop technology necessary to eliminate
discharge of pollutants into the navigable waters, waters of the
contiguous zone, and the ocean, and several specific provisions of
the legislation give impetus to consideration of land disposal as a
serious alternative for alleviating the water pollution problem.
One of the basic encouragements is the requirement that publicly-
owned treatment plants achieve secondary treatment results by 1977\
including removal of all floatable solids and 85 percent of suspended
solids. In addition to increased costs in general, this requirement
will result in greater quantities of sludge to be disposed of, a task
made more difficult in some cases by restrictions on ocean disposal
of sludge contained in the legislation. Thus an incentive for land
application of wastewater is produced since this technique has the
capability of meeting the secondary treatment requirement and hand-
ling a part of the sludge disposal problem as well.
Land treatment is also facilitated by provisions of the 1972 Amend-
ments which permit the use of federal grants for acquisition of land
that will be an integral part of the treatment process or is used
for ultimate disposal of residues resulting from treatment opera-
tions5. Grants cannot be used to acquire land upon which a
conventional treatment plant is located.
337
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Provisions of the Act and regulations adopted for its implementation
show a definite intent that land treatment be considered as an alter-
native form of waste treatment. For example, the legislative
provision requiring the Administrator of the Environmental Protection
Agency (EPA) to encourage the development of revenue producing waste
treatment facilities makes specific reference to recycling potential
sewage pollutants through the production of agriculture, silviculture,
or aquaculture productso. Another relevant provision is included in
the proposed regulations containing cost effectiveness analysis
guidelines. This provision requires the consideration of all feasible
alternatives, specifically including systems using land or subsurface
disposal techniques7.
Although this most recent manifestation of federal water quality
policy suggests and even encourages the use of land disposal where it
is most cost effective, primary responsibility still resides with the
states subject to the Administrator's approval of the state's permit
program^.
STATE
Land application of wastewater is generally subject to state control
as are other methods of waste disposal. Acceptance of this treatment
concept varies among the states. A 1972 study by Temple University
indicates that 14 states had a favorable orientation toward land
treatment and 11 were negative in their outlook, with the remaining
25 either neutral or not subject to classification on the basis of
available information^.
Control over land treatment facilities has largely been provided
within the discretion of the state regulatory agencies, with few
formal regulations having been adopted. A survey reported in a 1973
EPA publication conducted by the American Public Works Association
with state health and water pollution control agencies indicates that
most state agencies have no set policies on this phase of wastewater
handling or attendant environmental impacts, do not impose specific
conditions on installations, seldom inspect existing systems, and
seldom require monitoring procedures and the filing of official
reports on operation. Only five states indicated that official regu-
lations governing irrigation with wastewater were in effect: Arkansas,
Arizona, Colorado, New Mexico, and Texas. Only four states, Arizona,
Arkansas, New Mexico, and Texas, indicated that they have rules
governing the type of crops approved for wastewater irrigated lands.
Permitted crops range from "forage only" to "all types." Texas regu-
lations demonstrate concern over consumption of raw crops from waste-
contact areas, with a prohibition in effect against wastewater
irrigation of those crops to be consumed in the raw state. The few
states which invoke crop restrictions also specify the quality of
effluent to be applied to the land10.
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Other states in addition to those listed as having regulations govern-
ing wastewater irrigation have controls with regard to land treatment
in general. For example, Californial! and Idahol2 have regulations
of this type. These controls would appear to apply to any proposal
for wastewater irrigation.
LAND USE CONTROLS
Policy concerning land use control is currently undergoing consider-
able re-evaluation as indicated by efforts to enact federal land
use planning legislation and the establishment of land use control
mechanisms at the state level. Provisions of these new laws and
regulatory procedures will likely impose direct controls over land
application of wastewater, but until these programs are implemented,
the traditional controls imposed by local zoning ordinances and
private control measures will provide the most significant con-
straints.
The applicability of zoning ordinances to land treatment facilities
is a complicated matter because of dependence on such factors as the
provisions of enabling legislation and the terms of the particular
zoning ordinance involved in a given situation. Two different
situations may arise in which the applicability of zoning would be
significant. The first concerns the extent to which a governing body
is subject to its own zoning restrictions, and the second involves
application of zoning restrictions of a second governmental entity
where facilities are to be constructed on land lying outside the
jurisdiction of the owner.
With regard to the question of whether a governmental body is subject
to its own zoning restrictions, the answer is frequently provided by
provisions in zoning ordinances which exempt governmental uses from
their provisions. For example, The Supreme Court of Pennsylvania in
a 1952 easel3 upheld the right of a municipality to construct a sew-
age treatment plant in a residential district since the zoning ordi-
nance specifically permitted "municipal use." Where no specific
exception is made for governmental use, the decision of whether the
restrictions apply is sometimes based on a distinction between
proprietary and governmental functions. Proprietary functions are
generally held to be subject to zoning restrictions while govern-
mental functions are not!4. In general, government functions are
those imposed upon a municipal corporation by the state as a part of
the sovereignty of the state to be exercised by the municipality for
the benefit of the general public, both within and without the
corporate limits. On the other hand, proprietary functions are
those exercised with respect to a municipality's private rights as
a corporate body for the advantage of the inhabitants of the city
and of the city itself 15.
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Of course, the key question which arises is whether operation of sew-
age treatment facilities is proprietary or governmental in nature, a
determination which may have varying outcomes. In a 1935 New York
casel6, a municipality was enjoined from erecting a garbage disposal
plant in a restricted district on the grounds that it was performing
a proprietary act and therefore bound equally with all other persons
by the terms of its own ordinance which prohibited disposal plants.
An opposing viewpoint is expressed in a 1969 Vermont easel? which
holds the construction of a sewage disposal plant to be a govern-
mental function and therefore exempt from local zoning ordinances.
Variation in outcome also characterizes attempts by one governmental
body to apply zoning restrictions to sewage treatment facilities to
be operated within its jurisdiction by a second political entity. An
example of a case of this type where zoning restrictions were upheld
is given by a 1962 decision of the Supreme Court of Missoun'18, An
injunction was awarded to a county for prohibition of the construc-
tion of a sewage disposal plant by a city in a residential district
of the county. The opposite result was reached in a 1962 Arizona
decisionl9 in which the state supreme court held that the operation
of a municipal sewage disposal plant was exempt from zoning regula-
tions of another municipality in which the property involved was
located. After recognizing a division of authority as to whether
sewage disposal is a proprietary or governmental function, the court
took note of the fact that the weight of recent authority appears to
support the theory of a governmental function. This trend indicates
that municipalities are not likely to be inhibited by internal or
external zoning in the location of land disposal facilities in an
increasing number of localities.
In addition to formalized land use controls, land treatment facili-
ties may also be subject to private control measures where such
operations have a detrimental impact on surrounding property. Of
interest here is the system of civil law which defines private rights
and provides a mechanism for accountability where the activities of
one party injure or infringe upon the rights of others. This law is
embodied in the accumulated decisions of the courts and is enforced
by means of litigation, which may take the form of an action for
damages or suit for injunction.
The concept of private nuisance is likely to be a central element in
any legal conflict arising out of situations where land treatment
facilities create conditions which unreasonably interfere with the
use or enjoyment of other property. Land treatment facilities are
not likely to be declared a nuisance simply because of the dis-
pleasure of an adjacent landowner; substantial interference with a
legally protected interest is required. In determining whether a
given facility does constitute a nuisance, the court will weigh the
gravity of the harm produced against the social utility of the
activity in question. Since the utility of waste treatment to the
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general public cannot be questioned, suits based on nothing more than
a general objection to the establishment of such facilities almost
invariably have been unsuccessful. Another effect of the relation-
ship of such operations to the public interest is the refusal by the
courts in most cases to grant injunctions that would prohibit con-
struction or force cessation of operations21. Although cases exist
where sewage disposal plants have been enjoined22, the more common
remedy imposed by the courts is an award of compensate damages.
A successful suit for damages must be based on a showing of injury in
excess of slight discomfort or annoyance, but it is not necessary that
the property in question be made totally unusable or that an imminent
danger to health exist in order for a legal course of action to arise.
The concept of nuisance encompasses activities that create conditions
offensive to persons or ordinary sensibilities, including unpleasant
odors, loud noises, and disease-causing insects. The courts have
generally recognized the right to an action for damages where these
conditions are caused by the operation of sewage disposal facili-
ties". Damages which can be collected include compensation for
depreciation of property values and an award for personal dis-
comfort24.
If nuisance conditions are created by a waste treatment facility, the
right to recover damages is not likely to be nullified by the claim
that the facility has been properly designed and operated. A 1942
Iowa court decision25 addresses this issue with regard to a conven-
tional sewage treatment plant. The owner of the plant maintained
that liability should not be imposed because the plant involved was
of the most modern type, had been designed by a competent engineer,
and had been given approval by a state agency. The court held that
these factors did not relieve liability arising from the detrimental
impact on other property. To the extent that proper design and opera-
tion of facilities actually prevent adverse effects, the likelihood
of legal action is reduced, but compliance with such procedures is no
shield from accountability for injury produced.
In addition to the landowner whose use exists at the time of estab-
lishment of land treatment facilities, the owner who initiates a use
of near-by property subsequent to installation and operation of
treatment facilities also is likely to possess the right to maintain
a legal action for compensable damages in connection with property
injury. "Coming to the nuisance" is generally no bar to an action
for recovery. This principle has been applied to a variety of indus-
trial or commercial activities which were originally established in
undeveloped regions but were later encompassed by expanding urbani-
zation26. It has been indicated that public facilities are also
subject to such action. For example, the court in a 1951 Florida
decision2' which denied a request for an injunction, noted that an
adequate remedy for damages existed for actual injury to property
335
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produced by a garbage disposal plant which had been encompassed by
urban growth.
CONSTRAINTS IMPOSED BY WATER RIGHTS
The third basic category of potential legal constraints on land appli-
cation of wastewater consists of adverse effects on private water
rights that may result from alteration of water quality and natural
flow patterns. Although land treatment is intended to reduce overall
water pollution, any degradation of ground water quality may subject
the operator to legal action by ground water users. In addition,
ground water recharge may produce damage to others where the water
table is artificially raised. With regard to surface waters, the
principal adverse effect of land application is the reduction in
streamflow which may occur below the previous point of discharge and
result in injury to water users located there. Thus it is necessary
to consider several aspects of private water rights which may con-
strain use of land treatment.
GROUND WATER
Perhaps the most obvious legal constraint on land application of
wastewater imposed by ground water law concerns protection of quality.
Although it is generally believed that the majority of pollutants in
wastewater will not survive oxidation in the soil, it is likely that
certain residuals and trace contaminants will find their way to the
ground water. In some cases, the end result of the oxidation process
itself may be a form of contaminant.
The right of the landowner to uncontaminated ground water has not
always been recognized. The courts in some cases have been reluctant
to impose liability where ground water pollution has resulted from
lawful uses of land on the basis that such injury could not have been
anticipated", in other cases, however, the right to uncontaminated
water has been upheld and liability imposed on those responsible for
its pollution. One of the common methods of protecting ground water
quality has been to declare activities which cause its contamination
to be a nuisance29. in some cases the right to pure ground water has
been viewed as absolute, with liability imposed on the party respon-
sible for its degradation without regard to the reasonableness of his
activity or the care with which his operation is conducted^, it is
interesting to note that acceptance of the strict liability concept
in the law is increasing31, a fact which generally enhances the right
of an injured party to recover from those responsible.
One of the most difficult aspects of ground water pollution cases is
the problem of establishing a cause-and-effect relationship between
the polluted water supply and the alleged source of the pollution.
Since direct evidence as to the source is often impossible to obtain,
336
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the courts have often accepted indirect proof based on circumstantial
evidence in such cases. It is difficult to generalize with regard to
the type of evidence which will be sufficient in a given case, but
factors that have been considered include the proximity of the
alleged source, the existence of other possible sources, the time re-
lationship between the alleged pollution-causing activity and the
injury, and the capability of the suspected source to pollute3^ Be-
cause of the fact that ground water contamination suits are often
initiated and decided with relatively imprecise data, it would appear
desirable that provisions for monitoring ground water quality include
data collection prior to operation of the site as a treatment facility
such that background data will be available for comparative purposes
in the event that complaints of quality degradation arise.
In addition to the protection of quality, water law will also protect
the landowner from interferences with ground water levels which pro-
duce injury. Underdrains are a method of mitigating both the quali-
tative and quantitative effects on ground water, but to date they
have not been extensively used. A survey by the American Public
Works Association indicated that only 4.9% of the 122 disposal fields
examined had underdrains. Designers of the systems relied on evapora-
tion, plant transpiration, and ground water recharge to take up the
flow33. it must be recognized that under certain circumstances the
increased subsurface flow may reach adjoining lands and so raise the
ground water level that agricultural or residential development of
the property is adversely affected.
Liability for artificially raising ground water levels has been im-
posed by the courts. For example, there have been several cases
concerning damage to adjoining property as the result of the con-
struction of reservoirs from which there was subsurface leakage. In
an Ohio case34, the plaintiff proved to the satisfaction of the court
that a nearby impoundment had caused water to flow, ooze, percolate,
or seep into the land of the plaintiff, thereby rendering it sour,
wet, or swampy, and permanently unsuitable for use as farm land or
for subdivision and sale. The plaintiff based its claim for damages
on the concept that defendant had committed a "trespass"—a physical
invasion of the plaintiff's property which destroyed the Tatter's
right to the enjoyment thereof. The court held that liability was
absolute without regard to whether the defendant had used due care
in the construction and maintenance of the dam and reservoir.
An earlier Florida case35 had a very similar fact situation. The
court found in favor of the landowner injured by the subsurface water
on the basis that damming a stream and causing an increase in ground
water levels such that injury was produced was unreasonable. This
case also addressed the question of whether a defendant can escape
liability when the dam was built under authority granted by the
United States Government. An analogy could exist to the case of land
disposal since the federal government is likely to provide much of
337
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the funds for the project and in so doing gives its implied consent
to the project. The court in the reservoir case held that authority
to erect the dam did not justify an unreasonable use of the property
as it affects the rights of others.
SURFACE WATER
Rights to water in its natural state are considered and dealt with as
real property in almost all jurisdictions. Water differs, however,
from other real property in that it is the use of the water and not
the water itself which is the subject of property rights. This qual-
ification or condition is found in each of the two major water
doctrines prevalent in the United States—riparian and appropriative.
The riparian doctrine recognizes a property right in the water only
when the use being made is reasonable in terms of others having an
equal right. Under the appropriative doctrine, a property right does
not arise until the water has been put to beneficial use. So strong
is this requirement that it is often said that beneficial use shall
be the basis, the measure, and the limit of the right to the use of
water. There is general agreement that "beneficial use" and "reason-
able use" both carry economic as well as legal connotations.
The application of municipal sludges and effluents to land actually
constitutes an "add on" after water has been applied to beneficial
use by a local unit of government. Although this recycling has most
of the attributes of irrigation, the rate of application and other
parameters are defined not in terms of optimum irrigation but of
obtaining improved water quality. Improved water quality may well
be accepted as a national goal or objective, but unresolved is the
question of whether it can or should be obtained at the expense of
property rights in water as established by state law. The question
must be asked as to whether this recycling of wastewater is a
beneficial use or a reasonable one under our current water law
doctrines.
The general rule in those states following the appropriative doctrine
is that a water use once established will remain substantially un-
changed with regard to its effects on other appropriators. The right
in the use of water includes the right to change the place, nature,
and means of use as well as the point of diversion, but the right to
change is qualified in that it may not be exercised to the detriment
of other appropriators, including those with junior rights36. Thus a
conflict arises where a proposed modification in use involves a
change from non-consumptive use to consumptive use which will deplete
streamflow. Land application of municipal wastewater would appear
to fall into this category of change since irrigation consumes more
water than does traditional municipal use alone. In fact, the
appropriator located immediately downstream from the prior point of
waste discharge may be denied all use of the previously existing
return flow.
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of junior appropriates will necessarily be protected. A 1972
Colorado casej/ concerning a change in point of effluent discharge
is relevant to this issue. In this case, the court draws a distinc-
tion between a change in the point of diversion and a change in the
point of effluent return. The court acknowledges that an appropri-
ator may not change the point of diversion except upon conditions
which eliminate injury to other appropriates, but goes on to say
that changes in points of return of wastewater are not governed by
the same rules. It is held that there is no vested right in down-
stream appropriates to the maintenance of the same point of return
of irrigation wastewater, and in the absence of bad faith or arbi-
trary or unreasonable conduct, the same rule applies to sewage
effluent from a municipality or sanitation district. The court does
acknowledge that there may be instances in which a change of the
point of return may be enjoined, but the fact situation of this case
is not one of them. The case has a strong dissent which argues that
the language of the court in previous cases is not limited to situa-
tions involving a change in point of diversion but that the court has
set forth guidelines applicable to any change which an appropriator
might make in the mode or manner of use of his water right. Never-
theless, the majority holding in the case represents a viewpoint
that may permit land application operations to function without
accountability to those whose water rights are adversely affected
thereby.
The riparian doctrine is based on the simple premise that he who owns
land traversed by or bordering a flowing stream may make a reasonable
use of the waters thereof so long as such use is reasonable in the
light of others having a similar right. After making a reasonable
and proper use of the water for his own purposes, a riparian generally
must return all the surplus water to its natural channel before it
reaches the land of lower riparian owners^°. Because of the amount
of land involved in land disposal, it would seem unlikely that land
to be used for disposal would be so situated that the return flows
would naturally reach the stream of origin at a point above the land
of all lower riparians. Therefore, land application is likely to be
in violation of the rights of other water users on the stream.
The situation is further complicated where the return flows from land
application ultimately find their way to a stream different from
their origin. Interbasin transfers are generally not recognized
under the riparian doctrine. Of course, a cause of action in cases
of interbasin transfers or other violations of riparian rights does
not arise in the absence of actual injury to the rights of a riparian
landowner39. Therefore, legal obstacles to land treatment operations
may not exist where a water surplus exists. In the absence of a
surplus, the water rights of landowners on the stream may become a
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significant constraint. If these water rights are given full protec-
tion by the courts, land application may be excluded in some riparian
situations without special provisions for acquiring the water rights
of those affected or returning the effluent after land treatment to
a point above the lower riparian owners.
The riparian doctrine is basically concerned with the interests of
landowners who hold property adjacent to a stream by protecting the
quantity and quality of the flow. This procedure automatically
results in a substantial measure of protection to the natural water
course itself, its scenic attributes, and many instream uses such as
recreation and fish and wildlife habitat. More liberal interpreta-
tion by the courts on such questions as "standing to sue" and "class
actions" greatly expand the potential for liability where the recyc-
ling of effluents on lands significantly modify the regimen of the
stream. It thus becomes evident that surface water problems must be
acknowledged and effectively dealt with in the design of land
disposal systems to be located in the East.
SUMMARY AND CONCLUSION
In conclusion, it is obvious that consideration of potential legal
constraints must be an integral part of the planning and design of
systems for applying wastewater to land for the production of food
and fiber. Because of the nature of these constraints, they cannot
be treated as final design considerations but must be kept in mind
from the initiation of planning. Ultimate feasibility of a given
installation may well be dependent on these factors, and basic
aspects of the physical design may be controlled thereby. Failure
to give complete and timely recognition to these constraints is
likely to produce problems during the operational stage and result
in inefficiency and frustration in the application of the concept.
Only when these constraints are fully incorporated into the total
design framework can the potential of this technique be effectively
realized.
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Footnotes
1. Water Pollution Control Act of 1948, 62 Stat. 1155 (1948).
2. Federal Water Pollution Control Act of 1956, 70 Stat. 498 (1956).
3. Federal Water Pollution Control Act Amendments of 1972, 86 Stat.
866 (1972).
4. J_dL, sec. 301(b)(l)(B).
5. I^., sec. 201(g)l, 212(2)(A).
6. Id.., sec. 201(d)(l)
7. 40 CFR Part 35, Appendix A(e)(l).
8. Federal Water Pollution Control Act Amendments of 1972, 86 Stat.
866 (1972), sec. 402(b).
9. Center for the Study of Federalism, Green Land—Clean Streams:
The Beneficial Use of Waste Water Through Land Treatment. Phila-
delphia, Temple University, 1972, p. 226.
10. Environmental Protection Agency, Survey of Facilities Using Land_
Application of Wastewater, Washington, Environmental Protection""
Agency, 1973, pY 99.
11. Cali forni a Administrati ye Cocte, Title 23, Waters, Chapter 3, Sub-
chapter 15.
12. Idaho Board of Environmental and Community Services, "Rules and
Regulations for the Establishment of Standards of Water Quality
and for Wastewater Treatment Requirements for Waters of the State
of Idaho," sec. XI, 1973.
13. Lees v. Sampson^ Land Co...92A. 2d 692 (Pa. 1952).
14. 101 C.J.S. Zoning sec. 135.
15. James A. Ballentine, Ballentine's Law Dictionary, Rochester, N.Y.,
The Lawyers Co-operative Publishing Company, 1969, p. 530, 1012.
16. O'Brien v. Town of Greenburgh, 268 N.Y.S. 173 (N.Y. 1933),
aff'd. 195 N.E. 210(N.Y. 1935).
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17. Kedroff v. Town of Springfield, 256A. 2d 457 (Vt. 1969).
18. St. Louis County v. City of Manchester, 360 S.W. 2d 638 (Mo.1962);
see also Jefferson County v. City of Birmingham, 55 So 2d 196
TATa. 195TT:
19. City of Scottsdale v. Municipal Cout of Tempe. 368 P. 2d 637
(Ariz. 1962); see also City of Des Plalnes v. Metropolitan
Sanitary District of Greater Chicago. ?68 N.E. 2d 42F (111. 1971);
People Ex. Rel. Scott v. North Shore Sanitary Dist. 270 N.E. 2d
133 (111. 1971).'
20. See, e.g. Bader v. Iowa Metropolitan Sewer Co.. 178 N.W. 2d 305
TTowa 1970TrWard v. Hampden Township. 271 A. 2d 895 (Pa. 1970).
21. See, e.g.. Fields Sewerage Co. v. Bishop, 30 S.W. 2d 412 (Tex.
1930).
22. See, e.g.. City of Marl in v. Criswell. 293 S.W. 910 (Tex. 1927).
23. See, e.g.. City of Temple v. Mitchell. 180 S.W. 2d 959 (Tex.
T9?4).
24- See, e.g.. Aguayo v. Village of Chama. 449 P. 2d 331 (N.M. 1969).
25. Ryan v. City of Emmetsburg, 4 N.W. 2d 435 (Iowa 1942).
26. See, e.g., Hulbert v. California Portland Cement Co., 118 P. 928
. 1911); Mitchell v. Mines, 9 N.W. 2d 547 (Mich. 1943).
27. State ex. rel. Knight v. City of Miami. 53 So. 2d 636 (Fla. 1951).
28. See, e.g.. North East Coal Co. v. Hayes, 51 S.W. 2d 960 (Ky.
1932); Rose v. Socony Vacuum Corp. 173 Atl. 627 (R.I. 1934).
29. See, e.g., Love v. Nashville Agricultural and Normal Institute,
304 (Tenn. 1922); Swift and Co. v. Peoples Coal and Oil^Co,., 186
Atl. 629 (Conn. 1936).
30. See, e.g.. Berger v. Minneapolis Gaslight Co., 62 N.W. 336 (Minn.
1895); Berry v. Shell Petroleum Co., 33 P. 2d 953 (Kan. 1934).
31 W. Prosser, Handbook of the Law of Torts, St. Paul, Minn., West
Publishing Co., 1971, p. 509.
32. See, e.g., Hall v. Galey. 271 P. 319 (Kan. 1928); Bumbarger v.
Walker, 164 A. 2d 144 (Pa. Super. Ct. 1960); Jackson v. U.S.
Pipeline Co., 141 A. 165 (Pa. 1937).
33. Environmental Protection Agency, op. cit, p. 73.
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34. City of Borbenton v. Miksch. 190 N.E. 387 (Ohio 1934).
35. Cason v. Florida Power_£o.. 76 So. 534 (Fla. 1917).
36. Robert Emmet Clark, Ed., Waters and Water Rights, Vol. 5, Indian-
apolis, The Allen Smith Company, 1972, p. 428.
37. Metropolitan Denver Sewage Disposal Dist. No. 1 v. Farmers Reser-
voir and Irrigation Co.. 499 P. 2d 1190 (ColoT 197277™^
38. 93 C.J.S. Waters sec. 62.
39. See, e.g., Virginia Hot Springs Co. v. Hoover, 130 S.E. 408 (Va.
1925); Strattpn v. Mt. Hermon Bo.ys' School, 103 N.E. 87 (Mass.
1913).
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SOCIAL, POLITICAL, REGULATORY AND MARKETING PROBLEMS
OF MARINE WASTE-FOOD RECYCLING SYSTEMS*
John E. Huguenin
Judy T. Kildow
INTRODUCTION
The coastal areas of the United States are receiving ever mount-
ing public attention due to their increasingly apparent importance to
the national well being. The pressures emanate from the increasing
demands on the coastal waters and exploitation of their contained re-
sources combined with the increasing risk of destroying some of these
very resources by pollution due to the presence and activities of
large adjacent populations. Thus,at times,coastal zone resource ex-
ploitation and resource conservation appear to be conflicting ob-
jectives. But need they be conflicting?
It has become customary to consider any and all of the waste pro-
ducts of our society as pollutants,rather than resources, and to view
their discharge into the envirpnment as a form of pollution. However,
the nature and ecological effects of man's wastes are so highly vari-
able that their common designation and implied common impact on the
ecosystem may be a concept both simplistic and misleading.
There are at least some marine waste-food recycle concepts that
from a scientific and technical viewpoint seem very promising (see
Table 1). There is also currently considerable effort being expended
both nationally and internationally in the science and technology of
using societies' wastes as a resource in marine aquaculture. This
does not mean that there are not many serious obstacles to be over-
come before some of the proposed systems can be considered ready for
large scale operational use. Others, on the other hand, are already
being used on a large scale both intentionally and unintentionally in
sea food production. Agricultural and fishery processing wastes are
commonly used in formulated diets for animals both terrestrial and
aquatic, possibly without full understanding of some of the potential
This presentation results from the activities of an interdisciplinary
study group funded by the M.I.T. Sea Grant Program.
John Huguenin is a Research Associate in the Biology Department of
the Woods Hole Oceanographic Institution, Woods Hole, Mass.
Dr. Judy Kildow is an Assistant Professor of Ocean Policy in the
Ocean Engineering Dept. of the Massachusetts Institute of Technology,
Cambridge, Mass.
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Table 1. Uses of,"Wastes" in Marine Aquaculture
Waste
Possible Uses
Possible Benefits
Comments
Thermal effluents from
power plants
Secondarily treated
domestic sewage
Agricultural and fishery
processing wastes
Compacted solid wastes
Sewage sludge
Provide water temperature
control capability
As fertilizer to grow
marine plants
As components in formu-
lation of feeds
As construction material
for artificial reefs
As fertilizer or as input
for production of protein
to be used in animal feeds
Up to 500% (depending
on circumstances) in-
crease in yearly pro-
duction due to water
temperature control
Large "free" nutrient
source at base of
marine food chain and
also providing a form
of tertiary sewage
treatment
Reduced aquaculture
feed costs
Providing habitats to
enable denser concen-
trations of marine
animals
Reduced aquaculture
feed costs
Greal deal of current
research activity and
commercial interest
Current research
promising - many
possible variations
and applications
Already common
practice
Small scale research
in progress - Not a
preferred material
for reef construction
Small scale research
in progress
-------
risks involved. As an example, the over 600 state and federal fish
hatcheries in the U.S. alone utilize more than 41 million pounds of
fish food yearly, with almost 23 million pounds of this being organic
wastes (Hinshaw, 1973). The potential for the beneficial use of
power plant waste heat is widely recognized and is one of the aspects
of waste utilization currently receiving the most attention (Mathur
and Stewart, 1970^; Yarosh, 19733). The use of algae in processing
domestic sewage is accepted practice in many parts of the United
States. Current efforts are in progress to extend these practices to
produce useful food organisms in a marine environment (Ryther,
Dunstan, Tenore and Huguenin, 1972^; Allen, Conversano and Colwell,
1972^). The use of sewage ponds to grow aquatic food animals is not at
all a new concept (Allen, 1970^). Sewage products which are dumped in
large quantities into our coastal waters are certainly, at least in
part, responsible for the high sea food yields from some of our
estuaries (Ryther, 1971'). However, this increased productivity due
to fertilization with wastes is often unintentional, generally not
recognized and does not lend itself to management. The risks are
nevertheless present.
Time and research and development effort can be expected to make
some of these concepts both technically feasible and economically
attractive. It is not clear, however, whether even strong technical
and economic justifications are sufficient to assure the application
and exploitation of new developments by our society. Apparently not,
for there are other considerations and constraints. These obstacles
must be systematically and rationally analyzed before considerable re-
sources are expended to develop technically sound systems only to find
them useless due to critical legal, socio-political or psychological
factors.
ADVOCATES AND BASIS FOR OPPOSITION
Marine aquaculture, in general, is already constrained by a host
of institutional factors. Previous efforts dealing with these seem to
have concentrated on land and water rights (Henry, 1971°; Kane, 1970*;
Shields, 197010). However, there are many other problems upon which
effective opposition might focus (see Table 2). The use of resources
currently considered wastes in the production of marine foods may in-
tensify institutional scrutiny of such operations, due to both the
nature of the wastes and the increased visibility of the projects.
This is further complicated by the fact that marine aquaculture does
not have any formally organized interest groups to lobby for its in-
terests and for its rights in the heavily contested coastal zone. In
contrast there exist many well established and powerful groups which
could form effective opposition if they were to perceive marine aqua-
culture as a threat to their interests in coastal and estuarine areas.
There is no lack of vulnerable points for opponents to exploit. How-
ever, this is counterbalanced by the growing awareness of shortages
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Table 2. Potential Sources of Opposition to Aquac.ult.ure
'Illegal use of chemicals by aquaculturists.
•Local and state conservation and game regulations.
•Competition for sites from alternate users.
•Industrial fears of more pressures to reduce water pollution.
•Secondary products flooding small markets.
• Countermeasures to prevent poaching and vandalism.
•Pollution potential of large cultures.
•Alterations to coastal areas.
•Transplants of organisms both planned and unintentional.
•Characteristics of occasional disasters.
•Presence in cultures of nuisance diseases and parasites.
•Concerns over potential hazards to public health.
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and the need to effectively manage our coastal resources. The fact
that there are no organized advocates at present is a partial advan-
tage in that attitudes of potential political oppositions are still
flexible and there are no commitments to past mistakes. Waste food
systems in particular have unique possibilities for a broad appeal to
many different elements of our society not possible with straight
commercial aquaculture. Many of the potential opposition groups may,
if care is taken, become strong supporters. This is due to the multi-
objective possibilities of such systems which combine pollution con-
trol, growth of food and the use of otherwise wasted "resources".
This provides both a strength and a weakness. Making judgements in
areas where objectives conflict may prove troublesome. In addition,
there is the danger that with more research, what now appear to be
generally compatible objectives may prove to be incompatible. The
broad appeal may also lead to a premature "push" for acceptance re-
sulting in opposition based on scientific and technical issues which
could easily be diffused with more thorough research. Many of these
potential issues involve areas in which so little research has been
done that it is not even known with certainty whether or not sub-
stantial problems in fact exist. This is especially true for marine
waste-food recycle concepts, due to the many potential and unresolved
questions particularly in the areas of public health and quality
assurance. Combining two such critical human activities as food pro-
duction and the removal of wastes can very easily produce opposition
based on fear resulting from uncertainty.
PREREQUISITES FOR ACCEPTANCE
There are several prerequisites before societal acceptance of
waste-food or water reuse systems for general use is a realistic
possibility. First, all legitimate public health concerns must be
adequately assessed and resolved (Shuval and Gruener, 1973^). Two
examples where sewage products are involved stand out. One is the
problem of enteric virus (Ramas, 197012; Metcalf, Vaughn and Stiles,
197013)t and the other is the possible presence of known carcinogenic
chemicals in the input wastes. There are also unknowns involving the
transmittal and concentration of various "pollutants" through complex
food chains which include man, and the long term effects of these
processes. Systems must be developed to reduce or circumvent the
high risk areas, and adequate public health safeguards must be pro-
vided. If this is not done, there is very little chance for societal
acceptance unless the perceived needs are so imperative and pressing
that high risks are warranted. The inverse is also true. Definite
markets must either exist or be created for even low risk waste-food
systems to receive societal and regulatory acceptance. These markets
may be for direct domestic use or more indirect, such as for the
benefit derived from exports or even for non-material advantages,
such as for environmental enhancement. But these needs must be per-
ceived, and believed by at least a portion of our society for any
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hope of favorable actions. The very existence of this conference
indicates that, to some degree, this is already fact.
Given a latent but generally perceived societal need, potential
markets, and promising waste food system possibilities, at least
some favorable public policy decisions seem a prerequisite for the
establishment of any full scale demonstration projects. At a mini-
mum, it would require some indications that if the systems meet some
specified performance levels the outputs would be approved for public
use. It is important to remember that most systems at this point are
not completely proven, and that uncertainties also exist about both
performance at full scale and over economic viability. These un-
certainities can remain a basis for skepticism and opposition in
spite of successful research efforts. The economics, in particular,
of many proposed aquaculture systems are open to question, because
almost all the published research has been done in very small labora-
tory experiments and the little data that exists for large cultures
is generally proprietary information. In addition, pilot plant
facilities are usually designed to research a spectrum of possible
concept variations, operating conditions and management approaches.
As a consequence, they are usually much smaller than the ultimate
systems, since the flexibility required for their continually changing
experiments and from their physical plants would be cost prohibitive
at full scale. Therefore the operations and economics of such re-
search facilities, while very useful, have limitations when attempts
are made to directly apply these experiences to large systems de-
signed for routine use under closely defined operating conditions.
Thus, these uncertainties can be fully removed only with the design,
construction and operation of full scale demonstration systems, which
need a favorable public policy environment to justify the tremendous
efforts and expenses involved. This applied development stage may
be the weak link in aquacultural development (Trimble 1972^) due
to the current lack of government support and to the high risks and
insufficient incentives for private industry. However, it must be
emphasized that small scale laboratory testing and sub-scale pilot
plant facilities are an essential prerequisite for providing the
needed design information for full scale demonstrations. There are,
however, pressures to speed the development of promising waste-food
systems to large scale applications. Prematurely committed demon-
stration projects that fail, due to inadequate preparation pose a
real danger in that they may discredit basically sound solutions.
ermining "safe" levels of contaminants in foods poses
s
..
to all is that the S roducts found on the
349
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future systems. Also, while not necessarily easy, it is probably
not as restrictive to the aquaculturist as it may at first appear.
It must be remembered that the aquaculture output is a managed pro-
duct and inherently susceptible to much improved quality control
comparable to "wild" products, which in many cases have not even been
carefully monitored or analyzed. When analyzed, the latter may be
found to have surprisingly high levels of some "pollutant" whose
presence may not even be related to any activities of man (e.g.,
mercury in swordfish and other fish). Requiring completely "zero
additions" of any pollutant, such as is done for "known" carcinogenic
chemicals in applying the Delaney amendment to the Food, Drug and
Cosmetic Act of 1938, while allowing "non harmful" quantities of the
same substances if found "naturally", is certainly an unrealistic
double standard which could easily preclude the hope and potential
promised to mankind by aquaculture, whether it uses wastes in the
process or not.
CHOICES
What sort of policy options do the marine waste-food advocates
have? It is clear that the policies adopted by advocates as well as
their decisions in the fields of marketing and system design will
affect the types and severity of the opposition. A major option is
in the choice of the initial outputs which are somewhat independent
of the long term objectives of the projects and seem a flexible
variable based on what is currently known about aquaculture food webs.
Thus the initial outputs may not be marine foods for human consumption
but rather products for education, research, bait or only as food
additives. It seems probable that societal acceptance will be in-
versely proportional to the intimacy of the contact with the product
and its waste input (Bruvold and Ward, 197215). Thus, the probability
of successful societal adaption might be increased by initially con-
centrating on other than direct food outputs. Early systems should,
as much as possible, hedge against uncertainties by maintaining the
capability of producing a spectrum of different products. Another
option, assuming a direct food output is desired, is whether to pro-
duce relatively small quantities of high quality, high value "luxury"
sea foods or go for large quantity "protein". Production oriented
aquaculture operations in both developed and less developed countries
have consistently and without any notable exceptions attempted to
produce "premium" foods. In the less developed countries this has
often been primarily for export although local food shortages may
exist. In addition, experience has shown that cultured products al-
most invariably receive premium prices over the same product from
natural sources. Thus, if economic criteria alone are used, any
large scale aquaculture operation is almost certain to involve high
unit value products. However, waste food systems are much more like-
ly, due to their association with public utilities, potential health
hazards and involvement with current public concerns, to have decision
criteria that are not based solely on marketplace economics.
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Another major policy choice to be made by waste food advocates is
whether to go for a high degree of publicity, presumably favorable,
or adopt a policy of secrecy. Obviously, this decision in many cases
may not be completely within the powers of this group. Aquaculture,
in general, has been receiving a great deal of publicity, almost all
very favorable and also, by and large, unrealistically optimistic.
On the other hand, actual commercial aquaculture ventures have gener-
ally been carried out with a very minimum of publicity. This may be
due both to the proprietary nature of the operations and their vul-
nerability to opposition because of some of their practices, as well
as to the generally unfavorable legal/political environment. In
addition, successful aquaculturists have generally been well inte-
grated with their rural power structures, have usually conducted their
business completely on private land and have operated on a scale small
enough not to form a focus for opposition. In contrast, well organ-
ized efforts to set up large commercial aquaculture operations needing
substantial capital and specialized expertise have often met failure,
due in part to their planned scale of operations and association with
"outside interests".
A noticeable exception to this low profile policy have been opera-
tions carried out in cooperation with power plants. However, most of
these operations have been experimentally oriented rather than direct
commercial attempts. In the few commercial cases, publicity has been
due to the power company's desires for favorable public relations in-
volving their thermal discharges rather than any change of policy on
the part of aquaculturists. In addition, while these few operations
have not been opposed, they have been relatively small in scale with
little impact and they have been surrounded with an aura of research
and experimentation. Thus, reactions to these operations are not
necessarily indicative of the reception to be experienced by large
scale operational systems. It may not be reasonable to assume that
the past history of secret or semi-secret aquaculture operations is
a realistic possibility for future large aquaculture systems, es-
pecially if wastes are used. A policy of secrecy for the planning
and development of a large commercial system might be realistic only
if it were known with confidence that the use of wastes so lowered
the production costs and that the associated technical risks and
probabilities of unpleasant external effects were so low that the
risks involved with presenting society with a "fait accompli" would
be justified.
CONSUMER ACCEPTANCE
Assuming that all other problems were solved, there is still the
question of consumer acceptance of waste-grown sea foods. There are
several important variables involved. Probably the most critical is
the degree and circumstances surrounding the differentiation of
waste grown marine foods from other sources of the same products, as
may be required by regulatory agencies. This is a problem mostly in
the fields of packaging, labelling and advertisement. It is
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anticipated, but not yet proven, that the products will look, taste
and smell the same as their managed counterparts which are not grown
with "waste" inputs. This is obviously a critical assumption. If
little or no differentiation is required, there is in all likelihood
no marketing problem. Past rulings of the Food and Drug Administra-
tion and the Federal Trade Commission, suggest assuming the worst
case conditions.
Assuming that distinct labelling will be required, to what extent
does a consumer's feelings of repugnance for wastes, which are known
to be acquired rather than innate or physiological, carry over to
food products grown with such materials? Unfortunately, there does
not appear to be any available research directly dealing with this
interesting question. However, if the fishing aspects of the Santee
Project (Merrel et al., 196716) and the common use of wastes in agri-
culture are any indication, this associative link may either not
always occur, or can be nullified, even when the physical facts are
clearly known. There is also considerable literature on public
attitudes towards the closely allied concept of using reclaimed water
(Bruvold and Ward, 197017; Bruvold, 197118; Bruvold, 1972a19;
Bruvold, 1972b20; Gallop Poll, 197321). Small scale surveying at
M.I.T. (to be published) has shown good correlation of this data with
consumer attitudes towards seafoods grown with waste inputs. Even
studies on attitudes toward irradiated fish (Yankelovich, 196622) and
on fluoridation (Sapolsky, 19682^) show surprising similarities.
However, while it is relatively certain that a large segment of the
public would not oppose the use of wastes in marine aquaculture,
there is little information on the numbers or degree of activism of
either strong supporters or strong opponents. This is a critical
void, since small vocal minorities have often swayed public opinion
in similar situations as demonstrated by the history of local
fluoridation decisions (Sapolsky, 19682^).
It must be remembered that the fact that aquacultural products
are cultured and managed, presumably under adequate controls, is a
strong selling point and one exploited by all present commercial
aquaculture operations. The available literature indicates that
those individuals who approve of the use of potentially objectionable
inputs do so under the assumption that such systems, if established,
would have adequate controls. These feelings of assured quality may
be strong enough for some consumers to make waste-food products pre-
ferred over sea foods of "unknown" quality from other sources. In
all studies, the major sources of consumer opposition have been un-
certainties and intuitive feelings concerning uncleanliness, impuri-
ties and lack of public health safeguards. Thus, the public's con-
fidence in the safeguards and quality control of the output products
may well be the single most important factor in consumer acceptance
of waste grown foods. Obviously one incident of bad publicity in-
volving the quality of the products could be extremely damaging.
352
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These problems highlight the importance of deficiencies and in-
adequacies in monitoring and quality control technology. While very
sensitive analytic methods have been developed for detecting most
pollutants and contaminants, these methods, in many cases, are not
adequate for long term continuous or quick reaction monitoring in a
biologically active seawater environment, as would be required for
applications in operational systems. Research and development effort
is especially needed to apply and modify current laboratory methods
and equipment to produce reliable and practical monitoring systems.
CONCLUSION
In spite of the many problems (see Table 3), the future for
marine waste-food recycling systems is very promising. In fact, a
good case could be made that such systems are already operating un-
intentionally on a large scale in some regions of our coastal zone.
While at the present time the recycling of wastes into our food
supplies is neither planned nor managed, this is sure to change. At
some point, the increasing demands on the coastal zone for both waste
disposal and food production can be safely met only by acquiring some
degree of control over the systems involved. Only in managed situa-
tions can the risks be controlled and production increased. Our real
choice is whether this is to be done methodically or haphazardly. Due
to the required long lead times for planning, research and development,
the time for choice may be now.
ACKNOWLEDGMENTS
The authors wish to thank Drs. John Ryther, Leah Smith and
William Kerfoot for reviewing the draft manuscript.
353
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Table 3. Problem Areas Requiring More Effort
. Resolving potential public health hazards.
. Establishment of realistic "acceptable" levels for "pollutants".
. Better understanding of food chain dynamics.
. Applying existing technology to monitoring and control
problems.
. Support for promising "pilot plant" and "demonstration"
projects.
. Economic evaluations and comparisons with alternative
approaches.
. Market testing of outputs for quality and acceptance.
. Development of public and private institutional infrastructure.
354
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REFERENCES
1. Hinshaw, R. N. Pollution as a result of fish cultural activities.
Prepared for EPA by the Utah State Division of Wildlife Resources.
EPA-R3-73-009, 1973, 209 p.
2. Mathur, S. P. and R. Stewart (eds.). Proceedings of the Confer-
ence on the Beneficial Uses of Thermal Discharges. Albany, New
York, September 17-18, New York State Department of Environ-
mental Conservation, 1970, 17 papers.
3. Yarosh, M. M. (editor). Proceedings of the National Conference
on Waste Heat Utilization, Gatlingburg, Tenn., Oct. 27-29, 1971,
25 papers, 1972.
4. Ryther, J. H., W. M. Dunstan, K. Tenore and J. Huguenin. Con-
trolled eutrophication - Increasing food production from the sea
by recycling human wastes. Bioscience ,22(3): 144-152, 1972.
5. Allen, G., G. Conversano and B. Colwell. A pilot fish-pond
system for utilization of sewage effluent, Humboldt Bay,
Northern California. California State University Sea Grant Re-
port HSU-SG-3, 1972, 25 p.
6. Allen, G. H. The constructive use of sewage, with particular
reference to fish culture. FAO Technical Conference on Marine
Pollution and Its Effects on Living Resources and Fishing.
Rome, December 9-18, 1970, 26 p.
7. Ryther, J. H. Recycling human wastes to enhance food production
from the sea. Environmental Letters .1(2): 79-87, 1971.
8. Henry, H. P. A General Legal Perspective. Aquaculture a New
England Perspective. University of Rhode Island. New England
Marine Resources Information Program, 1971, pp. 51-56.
9. Kane, T. Aquaculture and the law. University of Miami. Sea
Grant Technical Bulletin No. 2, November, 1970, 98 p.
10. Shields, H. W. Aquaculture and the law. Proc. Gulf and Carib.
Fish. Inst. 22: 61-64, 90-96, 1970.
11. Shuval, H. I., and N. Gruener. Health considerations in renova-
ting waste water for domestic use. Environmental Science and
Technology £(7): 600-604, 1973.
12. Ramas, D. G. Viruses and sewage reuse. Proceedings of the
Waste-water Reclamation and Reuse Workshop. Lake Tahoe, Calif.,
Jan. 21-27, 1970, pp. 38-44.
355
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13. Metcalf, T. G., J. M. Vaughn and W. Stiles. The occurrence of
human viruses and coliphage in marine waters and shellfish.
FAO Technical Conference on Marine Pollution and its Effects on
Living Resources and Fishing, Rome, Italy, Dec. 8-18, 1970,
10 p.
14. Trimble, G. Legal and Administrative Aspects of an Aquaculture
Policy for Hawaii, State of Hawaii, Department of Planning and
Economic Development, 1972, 61 p.
15. Bruvold, William H. and P. C. Ward. Using reclaimed waste-
water - Public Opinion. Journal Water Poll. Control Fed. 44
(8): 1690-1696, Sept. 1972.
16. Merrel, John C., Jr., W. F. Jopling, R. F. Bott, A. Katko and
H. E. Pintler. Santee Recreation Project, Santee, California.
Final Report, U.S. Dept. of the Interior, W.P. 20-7, 1967,
165 p.
17. Bruvold, William H. and P. C. Ward. Public attitudes toward
uses of reclaimed water. Water and Sewage Works 117: 120-122,
1970.
18. Bruvold, William H. Affective response toward uses of re-
claimed water. J. of Applied Psychology 55:28-33, 1971.
19. Bruvold, William H. Public knowledge and opinion concerning
new water sources in California. Water Resources Research JJ
(5): 1145-1150, 1972a.
20. Bruvold, William H. Consistency among attitudes, beliefs and
behaviour. J. of Social Psychology 86_: 127-134, 1972b.
21. Gallup Poll Release. Americans Concerned that Water Resources
Will Become Permanently Low in 20 Years. Princeton, N.J.,
American Institute of Public Opinion, Wed., May 16, 1973.
22. Yankelovich, D. Cost benefit study of selected products in
Atomic Energy Commission's low-dose food irradiation program,
prepared for the A.B.C. by Daniel Yankelovich, Inc., N.Y.,N.Y.,
Report No. NYO-3666-1, 1966, 226 p.
23. Sapolsky, Harvey M. Science, Voters and the Fluoridation
Controversy. Science 162:427-433, 1968.
356
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RECYCLING FOR A PURPOSE-BUT FOR WHAT
PURPOSE? A SOCIOLOGIST'S VIEW
by
Lewis H. Irving, Ph.D.*
With the political and social unrest persisting in today's world,
the public is beginning to question the very existence of many of the
social institutions. One constantly hears statements such as: "There
is no need to be concerned with the population problems, because as
the population grows so will our level of technology and everything
will be O.K.—besides, it's my right to have as many children as I
want"; or "There is no real energy crisis, it's just the government
and big oil companies trying to drive the price of gasoline up, the
little man out and the customers off their backs. There is enough
energy for everyone." In essence, the people do not know which line
of rhetoric to accept and when a true social issue is presented they
view it with a jaundice eye. A key question which the physical scien-
tific community must address is "How do we determine the existing
public opinion toward a topic, and once known, how do we alter those
opinions to facilitate a social acceptance of the problems in order
to allow a joining of efforts on the parts of the scientific community
and the public community to abate the issue?"
Turner and Killian have suggested that
"At tijnes...problems arise for which tradition provides no
clear-cut solution. An issue is created and a public arises.
Public opinion is formed and reformed, often with startling
shifts, until the issue disappears. The major norms of a
society as embodied in its institutions persist for long
periods in spite of varying degrees of dissatisfaction with
them. But periodically social movements develop whicb^cul-
minate an institutional change and cultural revision."
WHAT IS PUBLIC OPINION?
In order to evaluate the attitudes of the public, one must first
understand that public opinion is the "...effective expression of the
public.... /realizing that; the public...is a dispersed group of people
"Assistant Professor of Sociology, Central State University,
Lewis M. Killian. Collective Behavior.
J. VAJ. i Aw ± y * ^t*^f^* * *• * • *•*• _ A
Engelwood Cliffs, Prentice-Hall, Inc., 1957, p. J.
357
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Interested in and divided about an issue, engaged in discussion of the
issue, with a view to registering a collective opinion which is ex- 2
pressed to affect the course of action of some group or individual."
Of course there are many definitions of public opinion but for purposes
of this paper the above suffices.
Consequently, one may interrelate public opinion and individual
opinion understanding that the feeling, attitudes and actions of the
group are attributable to the phenomena of the individual. "Public
opinion then becomes a form of group thinking, and the process bears
more than an analagous relation to the individual's 'complete act of
thought.'"1*
In order then to understand the attitudes of the group, one must
measure, in some form or another, the attitudes of the individual
toward the question under consideration. Peter Kelvin explained that
"...an attitude has at least two components: there is the
'object1 of the attitude or, rather, what the individual
knows or believes about it; and there is his feeling towards
it, which is the basis for how he evaluates it. If we...
look at the meaning we give 'attitude1 in everyday language,
we find a third component, by implication related to behav-
iour.'^
To examine the three components of an attitude from another perspective,
"Feelings are often referred to as the affective components, thoughts
as the cognitive component, and predispositions to act as the behav-
ioral component."°
To the layman the behavioral and cognitive components of attitudes
appear to be the most obvious factors for measurement; however, the
outward displays of personality do not necessary coexist with the
inward thought patterns and vice versa. To explain this in another
fashion: when a person discriminates either positively or negatively
toward another, it does not mean there is a coexisting positive or
negative prejudice acting in conjunction with the former. Therefore,
"Prom the standpoint of research technique, observable behavior is
in fact very difficult to measure, and the actual behavior observed
2Ibid. p. 219.
^Lunberg, George A. Public Opinion from a Behavioristic View-
point. American Journal of Sociology. 3£: 387-405, November 1930.
^Clark, Carroll D. The Concept of the Public. Southwestern
Social Science Quarterly. 13.:311-320, March 1933-
t>Kelvin, Peter.The Bases of Social Behaviour—An Approach in
Terms of Order and Value. Great Britain, Holt, Rinehart and Winston,
1970, p. 40.
6secord, P. F. and C. F. Backman. Social Psychology. New York,
McGraw-Hill, 1964, p. 97-
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may have relatively little to do with basic beliefs and feelings,"?
Consequently, the focus of attitude research is toward the affective
component. In essence, attitude measurement is the measurement of
feelings and opinions directed toward an object or issue.
This phenomena gives rise to one of the major difficulties
prevailing between the physical sciences and the social sciences. How
does one measure an ambiguous concept that has no mass or physical com-
ponent? To do this the social scientist has had to essentially rely
on a method of ordering or scaling.
ATTITUDE MEASUREMENT FOR THE FACILITATION OP CHANGE
Predictivity must necessarily be based upon extrapolative condi-
tions and the facilitation of attitude changes toward ecological
phenomena must be accomplished by congruence between theory and prac-
tice. In order to accommodate this task the community must be pre-
conditioned to accept the feasible technological solutions to perceived
problems. The principle of attitude measurement or scaling "...is a
form of planned collection of data for the purpose of description or
prediction as a guide to action or for the purpose of analyzing the
relationship between certain variables "° If one is to understand
the level of thinking of an individual or public toward a topic (e.g.,
how a public feels toward recycled products), one must develop an
instrument of measurement appropriate for the specific task. Once
this instrument has been developed, the data collected and analyzed,
the social researcher will then be able to formatively design a tech-
nique which will be useful in redirecting the public opinion toward a
more positive understanding of the concept.
To change the attitudes of a conmunity or society is not an ef-
fortless task, as Thorstein Veblen warned, "Institutions are products
of the past process, are adapted to past circumstances, and are there-
fore never in full accord with the requirements of the present."9
Lewis A. Coser further examined Veblen's theory as
"...a new technology erodes vested ideas, overcomes vested
interests, and reshapes institutions-in accord with its
own needs. But this process may take considerable time,
and in that time lag—when, for example, an industrial society
v
'Kelvin, p. 40.
^Oppenheim, A. N. Questionnaire Design and Attitude Measurement.
New York, Basic Books, Inc.,1966,p. 1.
9Veblen, Thorstein. The Theory of the Leisure Class. New York,
Modern Library, 1937, p. 191.
359
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is still governed by legal and moral rules dating from
the handicraft era—society suffers from the waste that is
brought about by the lack of correspondence between its
institutions and its technology."10
The change of attitudes of a social system ".. .implies a change
in the individual's order of values, associated with changes in his
beliefs and behaviour; and in essence any change in the way in which
the individual orders his environment naturally affects the predictions
which he makes about it and the way in which he adjusts to it and ma-
nipulates it."11 The ability of the individual to change to the new
technologies will be in concordance with the instrumentation used to
provide the special knowledge, the efficiency with which the communica-
tion or learning devices are utilized and the effectiveness or its
organization.
To further extend one's understanding of this phenomena, Turner
and Killian suggest that "Certain fundamental conditions will determine
the effectiveness of attempts to manipulate any type of collectivity."12
These fundamental conditions are:
"(1) All effective influence obviously depends first of all
on gaining access to the group to be influenced....
(2) .. .the receptiveness of the mass toward the proposed
course of action or thought. In the mass, the receptiveness
/meaning interests, motivations and understandings; is that
of the individual, since individuals must decide and act
(3) ...the possibility of carrying out the proposed
action....
fAnd finally;
(4) ...the inclination and opportunity to act, the recipient
still makes some evaluation of the appeal itself and of the
assumed source of the appeal."13
Coser, Lewis A. Masters of Sociological Thought—Ideas in
Historical and Social Context. New York, Harcourt Brace Jovanovich,
Inc., 1971, pp. 272-273.
llKelvin, p. 59.
12Turner and Killian, p. 2?7.
ISlbid. pp. 277-295.
360
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SUMMARY
In order to achieve a social change of attitude toward a new
philosophy of life the social scientist will have to be familiar with
the current thinking and trends being developed in the physical scien-
tific coirmunity. The social scientist will have to evaluate the cur-
rent level of thinking of the community, design a program to institute
social change and implement these changes in order to bring the social
acceptability of the community in line with the degree of current
technical know-how. This will require a formidable amount of lead
time, which heretofore has not been a luxury afforded the social
scientist. In short, the apathetic attitude demonstrated by the
general public and many decision-makers cannot be dispelled unless
social and physical sciences merge toward a collective approach to a
solution.
SELECTED BIBLIOGRAPHY
Clark, Carroll D. The Concept of the Public. Southwestern Social
Sciences Barterly. 13.: 311-320, March 1933-
Coser, Lewis A. Masters of Sociological Thought—Ideas in Historical
and Social Context. New York. Harcourt Brace Jovanovich, Inc.,
1971-
Kelvin, Peter. The Bases of Social Behaviour—An •Approach:'-in Terms of
Order and Value.Great Britain,Holt, Rinehart and Winston,
1970.
Lunberg, George A. Public Opinion from a Behavioristic Viewpoint.
American Journal of Sociology. 36.:387-405, November 1930.
Oppenheim, A. N. Questionnaire Design and Attitude Measurement. New
York, Basic Books, Inc.,1966.~
Secord, P. F. and C. F. Backman. Social Psychology. New York,
McGraw-Hill, 1964, p. 97-
Turner, Ralph H. and Lewis M. Klllian. Collective Behavior. Englewood
Cliffs, Prentice Hall, Inc., 1957-
Veblen, Thorstein. The Theory of the Leisure Glass. New York. Modern
Library, 1937-
361
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PART 6 NEW OR INTEGRATED SYSTEMS
SESSION CHAIRMAN
GEORGE H. ALLEN, Ph.D.
PROFESSOR OF FISHERIES
HUMBOLDT STA TE UNIVERSITY
ARCATA, CALIFORNIA
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THE MICHIGAN STATE UNIVERSITY
WATER QUALITY MANAGEMENT PROGRAM
by
T. G. Bahr,b R. C. Ball,C and H. A. Tannerd
INTRODUCTION
One of the Nation's greatest environmental questions is
what to do with vast quantities of municipal wastewater.
Conventional methods of wastewater treatment can con-
tribute importantly to wastewater clean up but the dis-
charge of even these wastes has created eutrophication
of lakes and degradation of waterways through the nu-
trient materials that they contain even after advanced
treatment. We are also becoming aware of perhaps an
even more important problem. Many products used by man
contain elements that represent scarce and diminishing
resources or compounds that have a high energy demand in
their manufacture. In an economy faced with both materi-
al and energy shortages it seems foolish to manufacture
products at high cost to both of these, use them once
and then discard them. But this is exactly how we handle
plant nutrients. We mine our increasingly limited sup-
plies of phosphorus and infuse our scarce fossil energy
into the production of nitrogen fertilizers in order to
sustain the food production that feeds the millions in
our cities only to waste these elements into the nearest
stream. This gross mismanagement coupled with require-
ments for high water and air quality and the difficulties
of removing nutrients to levels acceptable to discharge
into natural waters has prompted an extensive search for
alternate methods.
It is well known that nutrients present in wastewater can
be turned into the production of harvestable food and fiber
o
This program is supported by grants from the Ford Founda-
tion, Rockefeller Foundation, Kresge Foundation, the U.S.
Environmental Protection Agency, Office of Water Resources
Research, and the State of Michigan.
Director, Institute of Water Research, Michigan State
University
/-•
Associate Director, Institute of Water Research, Michigan
State University
Director of Natural Resources and Assistant Director for
Water Quality Management, Institute of Water Research,
Michigan State University
362
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if applied in appropriate amounts to the land or to the
water. The quantity and schedule of application of waste-
water to agricultural lands or to aquaculture systems to
achieve an optimal level of food or fiber production
and, at the same time, achieving a high level of water
renovation is not well understood at this time. The
number and depth of research studies in this area has been
very limited and there are many important questions vital
to human health, energy and resource conservation that
have not been answered. We believe that maximum efficiency
of research on these questions can be obtained from an
integrated study of recycling systems incorporating the
facets of both terrestrial and aquatic ecosystems. The
plans, estimates and designs for functioning reuse and
recycling systems cannot be based on concepts but must
be reduced to reasonably accurate estimates based on
experience gained with working model systems. Such sys-
tems will require a coordinated multi-disciplinary effort
of considerable magnitude.
DEVELOPMENT OF THE PROJECT
Michigan is a state with vast water resources, bordering
on four of the five Great Lakes. Our interests for the
future are all closely tied to the discharge of wastes in-
to these bodies of water. Almost without exception every
pollutant that leaves a sewage disposal plant or runs off
from our fields or urban areas will reach one of the Great
Lakes. This can be seen in Figure 1 by examining the
position of Michigan's major tributaries in relation to the
bordering Great Lakes. Recent estimates by staff of the
Institute of Water Research at Michigan State University
place phosphorus (P) losses to Lakes Michigan and Erie from
Michigan's lower pennensula at approximately 35 million
pounds per year. The greater Detroit area in southeastern
Michigan alone contributes nearly 20 million pounds per
year, nearly all of which is from municipal or industrial
sources (Bahr1). Michigan State University has a long
history of research on pollutants and nutrients in streams
(Ball and Bahr2) and a concern on the part of many of the
staff for the well being of our water resources. The
wastewater recycling project to be described in this paper
was designed and built as a direct result of these con-
cerns .
The development and administration of the project is a
major part of the water programs of Michigan State Univer-
sity's Institute of Water Research located on the main
campus. Prototype plans received financial support and
approval to continue from the Michigan State University
Board of Trustees in 1966. Since then we have been helped
353
-------
Figure 1
Prinicpal rivers in the State of Michigan and
location of the Red Cedar River watershed,
site of the Michigan State University waste-
water recycling program.
364
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and encouraged by many faculty, citizens and public of-
ficials in both state and federal agencies. Funding was
eventually obtained from the Ford, Kresge, and Rockefeller
Foundations and later from the U.S. Environmental Protec-
tion Agency and from the State of Michigan through its
Clean Water Bonding Program. The project construction
was completed during the Fall of 1973. Cost of construc-
tion, exclusive of land acquisition, totaled approximately
$2.5 million.
PROJECT DESCRIPTION
The physical facility for the Michigan State University
wastewater recycling project consists of four basic ele-
ments: (1) a conventional activated sludge sewage treat-
ment plant; (2) a 4.5 mile transmission line; (3) a lake
system; and (4) a land irrigation system. This system is
schematically shown in Figure 2. The following is a more
detailed discussion of the facility.
SEWAGE TREATMENT PLANT AND TRANSMISSION LINE
The East Lansing Sewage Treatment Plant services the City
of East Lansing, Michigan State University with its 50,000
students and employees, and the adjoining community and
represents the first element of our system. It is present-
ly undergoing modification and enlargement to a capacity
of 15,000,000 gallons per day. As an integral part of
this modification the Michigan State University program
will develop and operate a parallel unit within this plant
that will have a capacity of 2,000,000 gallons per day.
Our portion will differ from the total plant in that the
effluent being received will not have pre-treatment for the
partial chemical removal of phosphorus. The effluent
(secondary or primary) from this subunit can be directed
to a pumping station with a present capacity of 2,000,000
gallons per day and provisions for additional pumps to
increase its capacity to 6,000,000 gallons per day. Flow
will be transmitted through the second element of the sys-
tem, a 21 inch concrete-asbestos pipeline which traverses
4.5 miles to the southern border, of the Michigan State
University campus and on to the 500 acre research site.
Here it discharges into the first of four man-made lakes.
LAKE SYSTEM
The flow from the first lake is then by gravity through
each of the other lakes and to a control building and pump
house servicing the adjacent spray irrigation site. The
lakes have a total surface area of 40 acres with the maxi-
mum depth of 8 feet at each outlet structure and a mean
365
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PRIMARY and SECONDARY
TREATMENT
, -^v
X 4 J
\-~^~^^rJ
CONTROL
STRUCTURE
LAKE SYSTEM-186 ACRES
INCLUDING 40 ACRES OF LAKES
22 INDEPENDENT SPRAY
UNITS (REMOTELY
CONTROLLED AND
PROGRAMMABLE
GROUNDWATER
and EVAPO-
TRANSPIRATION
STREAM
TERRESTRIAL SYSTEM - 314 ACRES
Figure 2. Schematic of the Michigan State University
wastewater recycling system.
366
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depth of 6 feet. This depth was chosen to maintain the
entire bottom within the euphotic zone in order to en-
courage the growth of rooted aquatic plants. The bottom
was also contoured in a very uniform manner to ease their
mechanical harvesting. Each lake has a collection basin
at the outlet so that water may be lowered to collect
fish or other aquatic fauna in a very small area. This
area is serviced by a ramp to allow access by both boats
and trucks. Control of discharge and lake level is af-
forded by both sliding gate valves and slash boards. The
interlake transfer system and connection to the irriga-
tion site is so designed that effluent can be taken di-
rectly from the pipeline or water can be intercepted at
the discharge of any of the lakes in the system or mixed
from any combination of lakes (see Figure 2). This fea-
ture will afford researchers with a wide range of water
qualities to be applied and tested on the irrigation site.
MARSH SYSTEM
Marsh systems with their high rates of internal nutrient
cycling may prove to be an extremely efficient system for
the uptake and conversion of wastewater nutrients into use-
able products. To test the possibilities and feasibility
of this idea we constructed three, one acre marshes which
are fed from the discharge of Lake 2 in the system. Re-
turn water from the marshes enters Lake 3. The basins of
the marshes were constructed in a terrace design that re-
sulted in three zones of depths of 18, 24 and 36 inches.
It is estimated that this will allow us to create in these
basins biota quite comparable with natural marshes of this
area.
In the construction of the lake basins and marshes par-
ticular attention was given to the sealing of the basins
to prevent loss of water through the bottom soils. They
were sealed with native clay and percolation tests indi-
cated a low permiability of 0.07 inches per day.
LAND IRRIGATION SYSTEM
The last element of the system is a terrestrial site lo-
cated on 350 acres immediately south of the lake system.
As with much of the soils of the glaciated parts of Michigan
and the Great Lakes basin there is a large array of soil
types ranging from heavy clay to light sandy soils. Within
the terrestrial site are forested areas, a pine plantation,
cultivated fields and fields that have allowed to regress
into old-field plant associations. The land is gently
rolling and the entire area is drained by the Fenton out-
let which enters a tributary of the Red Cedar River which
367
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in turn flows into the Grand River, a tributary of Lake
Michigan (Figure 1). The irrigation site is bounded on
three sides by an 800 foot buffer zone where we will not
spray effluent at the present time but it is available
for overland flow irrigation and research not requiring
spraying of effluent.
Within the terrestrial area is a 145 acre spray irrigation
site. Twenty-two individual valves, remotely controlled
and programmable from the control building, direct the
flow of water to the sets of surface irrigation pipe.
Four, 700 foot tapered aluminum laterals extending north
or south from a valve comprise a set. Water supply to
each set is carried by a 21 inch underground pipe and the
system is designed for winter operation. Spraying is by
conventional Buckner 8600 sprinkler heads.
Within and surrounding both the lake and land sites we
have drilled approximately 60 wells to monitor the level
and quality of subsurface water. Depths vary from just a
few feet into the glacial drift to over 200 feet, within
the underlying sandstone aquifer. Approximately 1/3 of
these wells will be equipped with automatic monitoring
and sampling equipment as part of a major effort to charac-
terize the subsurface hydrology in the region. All wells
are cased, sealed and fully protected from external con-
tamination. Surface water flow for the entire watershed
in study will be measured by means of a network of weirs.
Many of these are now installed. Climatological stations
at selected points in the area provide the additional
information to generate a detailed look at the entire
hydrological cycle for the area.
TOTAL SYSTEM FLEXIBILITY
The physical facility as it was designed affords maximum
flexibility in the development of research involving an
integrated land and lake management system for the res-
toration of water quality and the recycling of nutrients.
We have the potential for hydraulically stressing any area
of the terrestrial system with effluent far in excess of
its capacity of handling it to the extreme of no water
application above that of natural rainfall. Within this
range we have the capability of spraying at a variety of
qualities as selected by the investigator, and on any
temporal pattern that lends itself to research in the
development of a particular management strategy. Table 1
gives the estimated loading rates of various chemical
parameters if secondary effluent were directly applied to
the irrigation site.
368
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Table 1. Estimated soil loadings per acre on application of one inch of East
Lansing Sewage Treatment Plant secondary effluent.
Ui
0\
<0
Concentration in
Secondary Effluent Grams per
Chemical Parameter Og/1) Acre inch
Organic Nitrogen
Nitrate Nitrogen
Nitrite Nitrogen
Ammonia Nitrogen
Soluble Phosphorus
Total Phosphorus
Total Carbon
Total Organic Carbon
Dissolved Organic Carbon
Suspended Solids
Volatile Solids
Chlorides
Iron*
Manganese
Zinc
Nickel
Copper
Mercury
2.2
3.07
0.25
9.70
1.1
4.9
150
30
20
63
25
261
0.81
0.09
0.19
0.11
0.06
0.00005
227
317
26
1261
143
637
15,450
3,090
2,060
6,489
2,575
26,883
83
9
20
11
6
0.005
Pounds per Pounds per Acre
Acre Inch Per Year **
0.5
0.7
0.06
2.77
0.3
1.4
34
6.8
4.5
14.3
5.7
59.1
0.18
0.02
0.04
0.025
0.013
0.00001
36
50
4.1
200
23
101
2,445
489
326
1,027
408
4,254
13.2
1.5
3.1
1.8
1.0
0.0008
*Iron is being added for chemical phosphorus removal at the East Lansing Sewage
Treatment Plant.
**At a rate of two inches per week between March and November (36 weeks).
-------
Within the capabilities of the system we can chlorinate
the effluent at several points including the point at
which it leaves the sewage treatment plant, at the point
where it enters the first of the lake series and at the
point where it enters the pump and distribution center
leading to the spray irrigation site. We can also chlor-
inate it before entrance into any natural surface outlet
stream.
RESEARCH PLAN
AQUATIC STUDIES
The lakes will serve a multiplicity of purposes chief
among which is the removal of nitrogen, phosphorus and
other trace constituents of the wastewater. The mechanism
planned to accomplish this is to incorporate these materi-
als into the biological systems of the lake. The attenua-
tion of influent material will come about by several mech-
anisms: (1) direct sedimentation to the lake bottoms; (2)
incorporation into the plankton populations followed by
precipitation or coprecipitation with the algae; (3) sec-
ondary incorporation into the animal populations of the
lake including crayfish, tadpoles, minnows, aquatic in-
sects, and food or forage fish; (4) aquatic macrophytes.
These higher plants will constitute a major mechanism for
concentrating and removal of dissolved materials from
inflowing effluent.
During the fall of 1973 ten species of aquatic macrophytes
were introduced into the lake system. Freshly cut material
was transported to the campus lakes from nearby natural
areas. Potamogeton foliosus was given general distribution
over the entire extent of the lakes and localized clones
of the following macrophytes were also established: P_.
pectinatus, P. crispus, Elodea canadensis, E_. Nuttallii,
Myriophyllum spicatum, Najas flexilis, Ranunculus sp. and
Vallisneria americana. Care was taken to exclude problem
species such as Ceratophyllum demersum. Based on the pre-
liminary studies of McNabb and Tierney^ we can expect net
yields approximating 2100 gm/m^ ash-free dry weight over
a six month growing period. Of this weight about 1.51
is P and 5% is N.
As the water flows from lake 1 through the sequence to lake
2, it can be diverted to 3 one acre marshes adjoining lake
2. The purpose of the marshes is to test the efficacy of
a marsh community in removing nutrients from wastewater.
There is some evidence that they are unusually proficient
in denitrification processes. The research strategy on
370
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these is to plant and develop marsh communities adaptable
to the uptake of high levels of nutrients, then pass
effluent through these three marshes at a rate compatable
with the maximum uptake of nutrient materials. The con-
trol of the marshes is individual and the flow can be reg-
ulated at different levels. Cognate research on the util-
ization of these marshes by waterfowl and wildlife will
be undertaken in detail. It is anticipated that they will
produce a harvestable crop of wildlife as well as serve
for basic research.
TERRESTRIAL STUDIES
Forest
Within the terrestrial system is an area supporting a
mixed hardwood forest typical of most woodlots in southern
Michigan. Here, the survival and growth of the trees will
be documented under different spray application regimes
and the penetration, uptake of nutrients, and loss from
the system will be measured by a variety of techniques.
Partially covered by the spray irrigation system is a pine
plantation which will serve as contrast for the deciduous
forest system. Plans for additional research include the
planting of trees that can be used for intensive cropping
on a short term rotation. It is presumed that these will
be used for pulp wood and their complete removal and
utilization will serve to take the accumulated nitrogen
and phosphorus that they have incorporated during their
growth completely out of the system.
Incorporated as a by-product of the forest research will
be a study not only of the nutrients removed from the
system but also a study of the return and internal cycling
of these materials in the form of leaf fall to the forest
soils. This offers the possibility of the selection and
management of tree types for maximum binding and holding
of those nutrients that we desire to either remove from
the system or have tied up in such a manner that they
will not enter the potable water aquifer.
Old Field - Plant Ecosystems
Preliminary work over the past several years has indicated
that the natural diversity of an old-field community may
be one of the most effective and efficient units for cap-
turing nutrients from the wastewaters sprayed on the land.
There is also evidence from these studies that spraying
them with nutrient rich effluent will appreciably change
the composition of the plant community. The efficiency
371
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of these plant communities in trapping nutrients and the
role of grazers, especially insects, in transporting nu-
trient material out of the study system will be a topic
of continuing research.
Cultivated Crops
In the demonstration phase of the Michigan State Univer-
sity program we are not only striving to clean up the
wastewaters of a city, but to also make use of those
materials in the wastewater that have been mined and fab-
ricated at considerable costs of natural resources and
energy. It is self evident that the transformation of
these resources back into useable food or fiber is an
essential ingredient in this demonstration. Thus, we
will be carrying out in-depth research on those crops
that can be used in this way.
Many crops now cultivated for either direct or indirect
human use can be benefited by the irrigation with nu-
trient rich waters. But in addition to testing the
efficiency of these known plant crops we will undertake
a wide spread search for plants that meet the rather
unique conditions that we have set up in our recycling
program. Over the centuries crops have been selected for
many characteristics among which are the ability to live
with a minimum of water and grow with a minimum of input
of nutrients. There is now a need to reverse this par-
ticular selection and choose plants that will thrive in
an excess of water and in rich concentrations of those
nutrients that promote growth. With these crops, when
they are found or developed from the gene pool of known
and possible crops of the world, we will again have to
select for palitability and other factors desirable in
plants to be used for direct or indirect food production.
It is recognized that certain plants take up heavy metals
and other materials that may be found in wastewater ef-
fluents and that these levels may reach the point where
they are unacceptable for either human or domestic animal
food. Before such judgements can be made it will be neces-
sary to demonstrate such uptake and consider the possibil-
ities of either rejecting these forms as food or seeking
new uses for them. Since one of the goals of such a pro-
ject is to keep heavy metals and other potentially haz-
ardous materials out of our streams and lakes it appears
desirable to concentrate them in plants produced in aquatic
or terrestrial systems. The problem of their utilization
would then become the focus of additional research. In
this manner we at least have the hazardous materials "in
hand."
372
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Soil Research
Any system such as the one proposed at Michigan State
University will be dependent to an important degree on
the: (1) selection of a site with soils compatable with
the concept of total waste management and recycling; and
(2) management of the soil complex in such a manner as to
accomplish the mission of the project over a long period
(approaching steady state); and (3) a subsurface geology
that both serves as a filter and does not present a barrier
to water movement downward from the water application site.
Detailed studies will be carried out on both the short
and long range effects on soil texture and composition of
heavy applicatons of wastewater. This will involve studies
of the retention of heavy metals in the soil mantel and
development of strategies that will allow the heavy appli-
cation of nitrogen in its several forms and yet allow the
transformation and uptake of the nitrogen into forms that
will either be held in the crops or be driven off to the
atmosphere in the form of gaseous nitrogen.
The site selected has a great variety of soils characteris-
tic of the Great Lakes drainage basin thus affording the
opportunity for in-depth research on wastewater application
to diverse soil types.
MONITORING PLAN
CHEMICAL AND PHYSICAL
As both a service and as a basic research effort there is a
need for continuous monitoring of a large array of chemical
and physical parameters connected with both the operation
of the wastewater treatment plant and with the lake and land
facets of the recycling system. As a service to all inves-
tigators working on the total project, there will be avail-
able data on 52 chemical parameters representing collec-
tions starting with the raw sewage entering the sewage
treatment plant, the attenuation and removal of materials
as they move through primary and secondary treatment and
as they enter the pipeline leading to the lake system.
The chemical parameters of interest will be checked as
they move through the lake system from one lake to the next
and into the pump station. Similar and further tests will
be made through the stream outfall system and to the sev-
eral areas of the spray irrigation site. A similar series
of analyses will be made from the test well system.
These will identify movement of chemical materials into
the soil mantel and down into the subsoil and ground water
aquifer if such movement does take place.
373
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Most chemical parameters will be serviced by the Insti-
tute of Water Research's chemical laboratory under the
direction of an analytical chemist and his staff. Within
the limitations of modern technology we will monitor the
chemical parameters through automated equipment both for
the savings in time and cost and for uniformity of results.
There will be a constant check on the quality of the chem-
ical work through the splitting of samples to outside
laboratories and duplication of analyses within the labora-
tory. This program will also be closely coordinated with
standardization methodologies set forth in the International
Joint Commission's program on pollution of the Great Lakes.
MICROBIOLOGICAL
One of the most widespread of all criticism of recycling
of wastewater has been in the arena of public health
concern. There appears to be general acceptance that the
bacterial content of such water can be controlled and re-
duced to completely acceptable levels through chlorination
at some stage in the recycling process. However, there
have been expressed doubts about the safety of using re-
cycled sewage effluent, regardless of the chemical and
biological stages that it has passed through. We know that
such recharges into the ground aquifers are widespread in
areas where sewage disposal plants empty their wastes
into streams which in turn recharge ground aquifers. How-
ever, in designing a recycling system it is essential
that all concerns of this type be answered fully and that
the final product of such a system be completely safe from
a health standpoint.
One of the major problems in identification of the health
hazards from a recycling system has been the high cost and
inadequate technology in identifying many of the more im-
portant viruses in dilute solutions such as one would find
in the recharge to a ground water aquifer. To address our-
selves to this problem we are establishing a fully equipped
laboratory capable of both routine and research analytical
efforts in determination of the total microbiological
problems involved in this project. Paralleling the chem-
ical monitoring program, the microbiological samples for
both bacteria and virus will be taken at every major trans-
fer point within the system. This will include identifi-
cation from the raw sewage through the treatment plant,
through the pipeline to the lake system and to all aspects
of the spray irrigation site. This will also include a
detailed consideration of the potential for dispersent by
aerosols in the spray irrigation process.
374
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SUMMARY
The total recycling concept that we are preparing to test
is based upon:
(1) The fact that our natural resources are limited in
supply and will, within the foreseeable future, become
critical both to industry and agriculture. This is partic-
ularly true of phosphorus and is well demonstrated by the
fact that the world is now competing for a relatively
limited supply of available phosphorus to feed a vastly
increasing world population.
(2) That materials, such as nitrogen, found in abundance
in our wastewaters will be in short supply immediately
and are of concern as well because of the high levels of
energy that they require to manufacture them.
(3) These two essential nutrients are very great contrib-
utors to the pollution of our streams, our inland lakes,
and the Great Lakes.
Thus, we believe that for the conservation of our es-
sential natural resources and for the reduction in the use
of energy and the protection of our water resources of
the country, it is essential that we both remove these
nutrients from the waters and also make use of them in
the production of food materials. The mechanism for doing
this is in part understood and in part there is a serious
lack of scientific knowledge upon which to base the re-
cycling and reuse of materials contained in wastewater.
Recently, in an unusual joint release, the Water Pollution
Control Federation and the American Water Works Associa-
tion stated their support for a massive research effort
to develop needed technology and evaluate the potential
health problems related to recycling of wastewaters to
domestic water supplies. Noting that "sound management
of our total available water resources must include con-
sideration of the potential use of properly treated waste-
waters as part of drinking water supplies," the joint
resolution pointed out the lack of adequate scientific
information about possible acute and long term effects on
man's health for such reuse, and also noted that the
essential fail-safe technology to permit such direct re-
use has not yet been demonstrated. The resolution em-
phasized the need for prompt action based on the fact
that "ever greater amounts of treated wastewaters are be-
ing discharged to the waterways of the nation and consti-
tute an increasing proportion of many existing water
supplies." Although indirect recycling has occurred for
375
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many years with no obvious indications of damage to the
public health, almost no effort has been devoted to the
complex and long term evaluation and quantification of
possible hazards related to the ingestion of recycled
wastewater or its by-products. Furthermore, the nature
of hazardous materials in wastewaters will require many
years of research to develop monitoring and treatment
processes essential to their removal or control.
Since this is a problem with applications throughout
the entire United States, the federal government can play
a major role in providing the kind of funds and coordina-
tion needed to implement the research, monitoring, and
pilot programs that must be developed to forward the pro-
gress in this effort. Because of the interrelated nature
of the many facets of a program such as this, it may well
fall to those universities with a large and diverse staff
to undertake an overall evaluation (systems analysis) of
the process and to develop demonstration and educational
programs that must accompany such an effort. This is what
is proposed in the Michigan State University program.
LITERATURE CITED
1. Bahr, T. G. (ed.). Ecological Assessments for Waste-
water Management in Southeastern Michigan. Technical
Report No. 29, Institute of Water Research, Michigan
State University. 327 pp. 1972.
2. Ball, R. C. and T. G. Bahr. Ecology of the Red Cedar
River. In: Whitton, B. A. and M. Owens (eds.) "River
Ecology,Tr~Blackwell Scientific Publications Ltd.,
London (In press).
3. McNabb, C. D., Jr. and D. P. Tierney. Growth and
Mineral Accumulation of Submersed Vascular Hydro-
phytes in Pleioeutrophic Environs. Technical Report
No. 26, Institute of Water Research, Michigan State
University. 33 pp. 1972.
376
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EXPERIENCES WITH A MARINE AQUACULTURE-TERTIARY
SEWAGE TREATMENT COMPLEX
*
John E. Huguenin
John H. Ryther
INTRODUCTION
Treated secondary sewage effluent has been shown to be a good
complete fertilizer for the growth of microscopic marine plants
(phytoplankton), which form the base of the marine food chain (Dunstan
and Menzel, 19711). From this somewhat surprising fact has emerged a
concept for a combined aquaculture-tertiary sewage treatment system
(Ryther, Dunstan, Tenore and Huguenin, 19722), which has been under
active investigation at the Woods Hole Oceanographic Institution since
late 1969. While the optimal operating points for the two objectives
of nutrient removal and maximizing aquacultural output are not coinci-
dent, they are close enough to make a combined system feasible.
The essence of the concept is a treated sewage-marine phytoplank-
ton-bivalve mollusk (oysters, clams, mussels, scallops) food chain.
However, in reality it includes a much more complex food web with
current research involving the utilization of flounder, lobster,
abalone, bait worms and seaweeds as secondary components in such a
system. This is due not only to a desire to hedge against uncertain-
ties, but is also based on experimental results which indicate that multi-
species aquaculture systems are more efficient and productive than
those with only one species (Tenore, Goldman, and Clarner, 1973 ).
Thus, efforts are leading to the development not of a single system
but rather to a spectrum of technically feasible systems. Efforts are
also underway to investigate the legal, political, regulatory, market-
ing and public health aspects of such a. concept. In addition, once
*John Huguenin is a Research Associate (engineer) in the Biology Dept.
of the Woods Hole Oceanographic Institution, Woods Hole, Mass.
Dr. John Ryther is a Senior Scientist in the Biology Dept. of the
Woods Hole Oceanographic Institution, Woods Hole, Mass.
377
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established, multi-species systems have value as research tools in
their own right, since complex natural processes involving different
trophic levels can be investigated under controlled conditions.
While a lot of work remains to be done, from experience to date both
indoors and outside (Dunstan and Tenore, 1972^; Tenore and Dunstan,
1973a^), it is clear that such systems can be made to efficiently re-
move nutrients (Goldman, Tenore, Ryther and Corwin, 19746; Goldman,
Tenore and Stanley, 1974O and produce rapid growth of marine organ-
isms with high survival.
Encouraging results and the need for better seawater research
facilities to more realistically evaluate the concept for practical
applications led to the design and construction of the Environmental
Systems Laboratoty (ESL) situated in Woods Hole, Massachusetts. The
primary intent was to provide a flexible experimental facility to en-
able research over the complete spectrum of possible development for
such systems.
Unfortunately, the ultimate application of the concept in New
England would require the use of waste heat from power plants to en-
able the animals to feed during the winter. Due to this complication,
these same ideas may prove simpler to implement on a large scale in
areas of the country with more seasonally uniform water temperatures.
Small scale experimentation has started at a site in Florida to
evaluate this concept in a semi-tropical environment, and a larger
scale facility in that area is now in the planning stage. For the
same reason, the U.S. Pacific Coast is also of interest.
DESIGN PROBLEMS
In terms of system design, the nature of the nutrient source
(i.e., secondary sewage or not) is for most purposes irrelevant. The
major design problems are those that would be common to any other re-
search oriented marine aquaculture system of equal complexity. The
main design constraint was clearly uncertainty over system require-
ments. This was due to both the continually changing research ex-
periments and the evolution and refinement of the concept itself.
Since quantitative requirements could only be defined with confidence
for the relatively near term, at most about two years, designing for
system flexibility and amenability to modifications became very im-
portant.
An interesting fact is that much of the necessary biological in-
formation needed for the development of aquaculture systems is not
available. This problem exists for several reasons, even for species
that have been relatively well studied. In spite of the tremendous
amount of information available on the biology of some marine animals,
the data from recognized experts can cover such a range of values as
to be useless. As an example, the published respiration rate of
oysters varied by a factor of more than twenty. On top of this
378
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uncertainty was the fact that within the components of our system
there are many other sources and sinks for dissolved oxygen. Also
surprisingly, important design variables have sometimes never been
investigated and published in spite of the voluminous literature
available. For us such a critical variable was the efficiency with
which shellfish convert 'different kinds of food to shellfish meat
(Tenore and Dunstan, 1973b8, 1973c9).
Since the individual circumstances surrounding any particular
operation can so easily alter the biology of the system, the best
approach, even where apparently good information exists, is the actual
testing of small scale systems under conditions as close as possible
to those to be encountered. While such testing can be very useful in
reducing the risks and developing nominal relationships and sizing
criteria, there are nevertheless some remaining pitfalls, especially
if indistinct research objectives are involved. Even for commercial
operations whose design objectives can be quite unambiguous,, there
are problems of determining system economics and the optimum scale
for operations as well as risks of major changes in system configura-
tion dictated by improvements in state-of-the-art, market considera-
tions, or institutional factors.
The engineering problems to be encountered include those due to
the corrosive properties of seawater, toxicity of many materials to
marine organisms, biological fouling of pipes and equipment, and the
lack of any readily available sources of bioengineering design in-
formation. On any specific project, areas involving design risk
should be recognized and acknowledged. Many of these risks, while
not capable of being completely eliminated, can be reduced by col-
lecting information on previous or related endeavors (Clark and
Clark. 196410; Lasker and Vlymen, 196911; Pruder, Epifanio and Malout,
197312; Strober, 197213), by small scale testing, and by careful
design to minimize the consequences of bad judgements. Due to the
large uncertainties in aquaculture systems, there is a high premium
on flexible designs and systems with the capability to readily under-
go modifications to meet changing requirements.
DESIGN FEATURES
The basic configuration adopted for the facility designed, at
least in part, as a "pilot plant" for the previously described con-
cept is shown on Figure 1. This system, from two head boxes, is a
gravity flow system with the six ponds, eight raceways and settling
pond in order of decreasing elevation. The settling pond and algae
ponds are prepared sand surfaces covered with 20 mil plastic liners,
a relatively inexpensive form of construction readily expandable to
much larger sizes. The raceways are concrete. It will be noted that
experiments can be conducted in an indoor wet lab, on a very flexible
outdoor test area and in the larger units, providing a choice of ex-
perimental sizes. Figure 2 shows the present piping configuration of
379
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the physical plant. This figure indicates that the outdoor units can
be operated with a variety of water depths and flow conditions as well
as enabling sequential on line operations in physically separated
units. Services such as raw seawater, filtered seawater, nutrient
supply, temperature controlled seawater, fresh water, electric power,
drains and oilless compressed air are available in many locations and
could easily be provided at others. The pipe materials are high
density polyethylene for the main seawater lines to and from the beach
and polyvinyl chloride (PVC) for most of the smaller on-site piping.
Care was taken in the design to assure easy access, for maintenance
and modification, to as much of this piping as was possible.
Several of the subsystems give the facility considerable added
research capability. A separate nutrient distribution system, which
includes three 8,000 gal. fiberglass tanks, a headbox and piping, can
distribute any pumpable fluid, such as secondary sewage, an artificial
media, a food slurry or even a "pullutant", to individual ponds or
raceways. The four impervious-carbon heat exchangers provide a
significant controllable seawater heating capability. This capability
can remove the effects of seasonal water temperature variants as an
uncontrolled variable in experiments, enables year round operations
and enables reasonably large-scale research on thermal effects to be
performed.
The sizes of the larger outdoor units were chosen to provide
results and experiences applicable to much larger facilities and still
have an acceptable initial capital cost. Due to the multi-objective
character of this facility the relative number and sizes of the com-
ponents are not necessarily those indicated by scaling up the sewage-
algae-shellfish system. If other research objectives were to be
sacrificed, this complex could ultimately treat the effluents (if
available) of up to 500 people and perhaps produce around four tons
of shellfish meat annually. However, it must be remembered that the
primary output of this facility is technical information and that the
economics of a research group and its facilities are vastly different
from those necessary for commercial operations. A facility built for
commercial use would have been designed much differently.
EXPERIENCES TO DATE
The major construction activities were completed in the fall of
1973 and the seawater system was permanently activated on October 30.
The next day 300,000 juvenile oysters arrived and initial operation
c ommenced.
The pond design has so far proven very satisfactory. In spite
of a good deal of activity there have been no serious problems with
punctures of the polyvinyl chloride liners. A cinder block dropped
on its corner produced only a small puncture in one of the ponds,
which was easily patched. Some of the ponds have been frozen so
solidly that people could walk on the ice and no damage to the liners
382
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has been observed. In addition, the liners can be readily cleaned,
even after being heavily fouled with filamentous algae. Still to be
determined is the long term performance of the liners, especially
with respect to sun damage. The expected useful life is five years
but other, slightly more expensive, liner materials are stated to not
be subject to this damage.
Overall, winter operations of the total complex have given prob-
lems far less severe than anticipated. Performance of the heating
and circulatory system provided for two of the six ponds has been
better than planned. We have been able to maintain water temperatures
in these as high as 75°F, but more normally set at about 60°F, even
with air temperatures in the low teens and with lower than anticipated
heat additions. Dense continuous flow marine phytoplankton cultures
of up to 2 x 10 diatoms/ml have been easily maintained for many weeks
in these ponds with a daily harvest of 30% of the culture volume.
The densities of these cultures are considerably higher than those
achieved in our smaller scale experiments. We believe these 36,000
gallon diatom cultures to be the largest in the world. Unfortunately,
due to the lack of a large tank truck, these large cultures have so
far been operated with concentrated liquid fertilizers rather than
with secondary sewage as originally intended.
The phytoplankton grown this winter have been fed continuously
on an in-line basis to 300,000 juvenile oysters and more recently
150,000 juvenile hard clams (quahogs) maintained in raceways supplied
with heated (60°F) filtered (20 micron) seawater. The temperature
drop across a forty foot concrete raceway, even under very cold con-
ditions and low flow through times (about 8 hours), has been less than
2°F. It is too early to say anything about the winter growth of
these shellfish, except that it has been substantial.
Several aspects of our operations, however, have proven trouble-
some. The five specialized carbon lined pumps with carbon impellers
have provided many problems, mostly in the area of not meeting per-
formance specifications and excessive water leakage at seals. In
addition, a planned traveling service platform has not yet been
procured, making access and the handling of stacked shellfish trays
and other loads in the raceways very difficult. This unit and a large
tank truck are currently the only important components still missing
from the system.
More biologically oriented problems have also arisen. The
valance heaters installed to heat the building were manufactured with
a coating of some hydrocarbon, which has contaminated the building
but is gradually burning off and, fortunately, does not seem to have
affected our current research. Undesirable growths on the sides and
bottoms of the ponds and raceways have been less of a problem than
anticipated, but are expected to get worse with the coming of spring
and simmer. As the cultures in the algae ponds get denser the un-
desirable growth on the sides is markedly reduced. This is a result
383
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which was not predicted from our smaller scale experiments. However,
removing fouling and accumulated organic debris is still a large
potential sink for man-hours and the development of satisfactory
methods and equipment to minimize the problem may be one of the keys
to practical forms of marine aquaculture.
OUTLOOK FOR THE FUTURE
Several potential problems must be investigated and resolved be-
fore the promising work already done on the use of treated sewage in
marine aquaculture can be beneficially applied on a large scale. All
potential public health hazards (Shuval and Gruener, 1973^) must be
thoroughly investigated and where real hazards are found to exist,
means must be found to eliminate or circumvent the problem. The
threat from enteric virus and the possible presence of some carcino-
genic chemicals are two areas of particular importance. If such re-
search is not done there is little likelihood of acceptance of this
type of system by either the public or the regulatory agencies. In
addition, continual small scale controlled experimentation must be
carried out with the purpose .of increasing efficiency and learning more
about system dynamics. The gains from such experimentation can be
substantial. As an example, during the year and a half between the
preliminary design phase and the construction of the ESL, the treated
sewage handling capacity of the ponds (size being constant) increased
by more than 3007. and the required seawater flow to the raceways was
cut 907.. Additional improvements are a distinct possibility.
The current ESL is a subscale pilot plant with multiple objec-
tives. No attempt was made in the design to enable its potential
"revenue" to exceed its costs, since its small physical size, the size
and composition of its staff, and its flexible research objectives
precluded this possibility. The facility will, however, produce
adequate quantities of waste-grown seafoods for testing in related
research projects and possibly even for the critical function of pre-
liminary market testing. The emphasis has not been on maximizing pro-
duction but rather on conclusively proving technical feasibility at a
realistic scale of operation and to exploring the practicality of such
systems for large scale applications. While technical feasibility
appears relatively assured, the economics and acceptability of the
ultimate system cannot yet be determined. They are contingent on a
great many factors including methods and equipment still to be de-
veloped.
A few years of experience with the ESL in improving system
efficiency, researching risk areas, developing better monitoring and
control methods, and reducing production costs is needed to provide
the information necessary for realistic evaluation and decision
making regarding the value of the basic concept. With this and similar
projects providing the needed design information, full scale demon-
stration projects may shortly become realistic possibilities.
38H
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REFERENCES
1. Dunstan, W. M. and D. W. Menzel. Continuous cultures of natural
populations of phytoplankton in dilute, treated sewage effluent.
Limnol. Oceanogr. 16(4):623-632, July 1971.
2. Ryther, J. H., W. M. Dunstan, K. R. Tenore and J. E. Huguenin.
Controlled eutrophication - Increasing food production from the
sea by recycling human wastes. Bioscience 22(3):144-152, March
1972.
3. Tenore, K. R., J. C. Goldman and J. P. Clarner. The food chain
dynamics of the oyster, clam, and mussel in an aquaculture food
chain. J. exp. Mar. Biol. Ecol. 12:152-165, 1973.
4. Dunstan, W, M. and K. R. Tenore. Intensive outdoor culture of
marine phytoplankton enriched with treated sewage effluent.
Aquaculture 1:181-192, 1972.
5. Tenore, K. R. and W. M. Dunstan. Growth comparison of oysters,
mussels and scallops cultivated on algae grown with artificial
medium and treated sewage effluent. Chesapeake Science 14(1);
64-66, 1973a.
6. Goldman, J. C., K. R. Tenore, J. H. Ryther and N. Corwin.
Inorganic nitrogen removal in a combined tertiary treatment-
marine aquaculture system - I. Removal efficiencies. Water
Research 8:45-54, 1974.
7. Goldman, J. C., K. R. Tenore, and H. I. Stanley. Inorganic
nitrogen removal in a combined tertiary treatment-marine aqua-
culture system - II. Algal Bioassays. Water Research 8:55-59,
1974.
8. Tenore, K. R. and W. M. Dunstan. Comparison of feeding and bio-
deposition of three bivalves at different food levels. Marine
Biology 21:190-195, 1973b.
9. Tenore, K. R. and W. M. Dunstan. Comparison of rates of feeding
and biodeposition of the American oyster, Crassostrea virginica
Gmelin, fed different species of phytoplankton. J. exp. Mar.
Biol. Ecol. 12:19-26, 1973c.
10. Clark, J. R. and R. L. Clark. Sea-water systems for experimental
aquariums - A collection of papers. U.S. Bureau of Sport Fisher-
ies and Wildlife, Research Report #63, 1964, 192 p.
11. Lasker, R. and L. I. Vlymen. Experimental sea-water aquariums.
U.S. Bureau of Commercial Fisheries, Circular 334, 1969, 14 p.
385
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12. Pruder, G., C. Epifanio and R. Malout. The design and construc-
tion of the University of Delaware Mariculture Laboratory. Sea
Grant Report DeL-SG-7-73, University of Delaware, 1973, 96 p.
13. Strober, W. J. A small bioassay laboratory designed for experi-
mental thermal effects evaluation. Circular No. 72-1, Fisheries
Research Institute, University of Washington, 1972, 12 p.
14. Shuval, H. I., and N. Gruener. Health considerations in
renovating waste water for domestic use. Environ. Sci. & Technol,
7(7):600-604, July 1973.
356
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POLYCULTURAL WASTEWATER RECLAMATION AT
CALIFORNIA POLYTECHNIC STATE UNIVERSITY -
AN ACADEMIC INSTRUCTIONAL SYSTEM
by
Dr. Richard J. Krejsa *
INTRODUCTION
When I attended Michigan State College in the early 50's,
it was called a "cow college" partly because of the
taunting disdain of midwestern football rivals, and partly
out of respect for the college's self-reliance on campus
grown food and dairy products. I am now on the faculty of
California Polytechnic State University, which also once
was a self-sufficient "cow college". While it is not
feasible to return to complete self-sufficiency, we are
actively exploring ways of regaining a certain amount of
integrated independence wherever possible. This presen-
tation constitutes a progress report of one such attempt.
Our polycultural wastewater reclamation system is still
more a concept than an accomplished reality. It is part
of an educational experiment based on the realization that
a multi-disciplinary approach to societal and technologi-
cal problems is necessary.
Goal
Our goal, basically is to make a resource out of waste-
water, and to educate students and the public in the
methods and philosophy necessary to do so.
Objectives
The objectives of our proposed polycultural wastewater
reclamation system are four fold:
* Associate Professor, Biological Sciences Department
California Polytechnic State University, San Luis Obispo,
Ca., and Supervisor,Fifth District, County of San Luis
Obispo.
** Portions of this investigation were supported by a
grant from the Creative Activity Research Effort (CARE)
program at Cal Poly, and by funds allocated to student
projects through the Student Enterprise Program of the
Cal Poly Foundation.
387
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1) To propose and investigate alternative biological
and agricultural strategies of secondary treated
wastewater reclamation and reutilization;
2) To monitor changes in water and soil quality
attendant -with the processing of wastewater
through our polyculture system;
3) To introduce students to practical and innovative
technologies;
4) To educate the general public that "waste" water
need not be wasted.
Accomplishments To Date
Over a two year period, six successive classes of Agri-
cultural Engineering students built the 50 acre-foot
reservoir (Fig.l) as a practical class project while
learning how to operate tractors, dozers and other heavy
equipment. This reservoir will serve as the Biological
Treatment Lagoon. Other Ag Engineering students designed
and constructed experimental closed-system aquaculture
units for rearing catfish and trout. Still others con-
structed automatic feeders, and bulk harvesting equipment,
and compiled specific bibliographies on the engineering
aspects of aquaculture.
A student in Animal Science grew St. Peter's fish, Tilapia
mossambica, brown bullheads, Ictalurus nebulosus and clams,
Corbicula manillensisC?), in an experimental backyard
polyculture greenhouse!. A Crops Science student tested
the utility of secondary effluent on certain grass crops.
Students in an Ag Business Management class in communica-
tions surveyed local consumer attitudes on the acceptance
of farm grown catfish and successfully promoted the sale of
farm grown fish at a local chain supermarket.
A Biological Science student compared growth patterns of
cage-cultured channel catfish reared in different popu-
lation densities (Fig.2a,b) . Another biology student
(Fig.2c) concocted an experimental fish food made from
dehydrated steer offal, cafeteria kitchen scraps, fish
meal, and agricultural crop wastes, and then pelletized in
our campus feed mill. The growth rates of cage-cultured
catfish fed on the experimental diet were compared to
those from control fish fed on standard Trout Chow.
Another young biologist studied the behavior of hatching
catfish fry and helped design new incubation and hatching
techniques. Others yet compared the behavior and growth
of fingerling catfish in normal irrigation water and the
secondary effluent from the California Men's Colony treat-
ment plant, studied the ultrastructure of developing cat-
358
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Figure 1. Site Location of Cal Poly Reclamation Unit.
Diagram legend - a. CMC treatment plant; b. newly con-
structed 50 acre-foot Biological Treatment Lagoon: c.
site of proposed aquaculture units; d. 10 acre-foot
irrigation ponds; e. irrigated crop land area; f. Chorro
Creek; mb = City of Morro Bay, 5 miles west on Highway 1;
slo = San Luis Obispo, 7 miles east.
Upper photo - view of Chorro Valley looking east, CMC
Treatment Plant on the right of reservoirs. Lower photo -
view of reservoir area, looking east.
fish skin using the techniques of electron microscopy, and
examined the skin of catfish for evidence of bacteriologi-
cal pathogens.
Two students from the School of Architecture and Environ-
mental Design did their senior project on the design of a
simple, efficient experimental fish hatchery using space
frame technology3. A class of 12 design students spent a
portion of the academic year running structural analyses
of the roof design created by the two senior project
students. Still another design class of 32 students spent
389
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(a)
V
(c)
Figure 2 Aquacultural experimentation at Cal Poly.
a Floating Cage culture density/growth experiment area.
Sheppard Lake: b. Weighing channel catfish grown in cage
culture: c. Sampling channel catfish grown on experi-
mental diet concocted from wastes.
390
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the recent winter quarter attempting to incorporate and
synthesize the multi-purpose aspects of the proposed poly-
culture reclamation project into a functional whole. They
came up with several innovative design concepts, two of
which are presented here (Figs. 3,4).
All of these preliminary and exploratory analyses were done
with minimum expense and maximum enthusiasm. The construc-
tion of the new 50-acre foot reservoir was completed last
Spring and it was filled for the first time last Summer.
The program announces this meeting as "The First Inter-
displinary Conference of Its Kind". As can be seen above,
our Cal Poly project has been interdisciplinary from its
inception over two years ago. Even if the production
aspects of the project were to go no further now, we would
deem the educational value of the project as worthwhile and
valid.
Historical and Political Perspective
The current form of the Cal Poly project evolved as the
result of the interplay of several factors, some of which
have been described above, and others which will be
described from a historical and political perspective below.
Consumptive water uses within the County of San Luis Obispo,
as well as throughout the Central Coast region are taxing
the capability of the watersheds and groundwater basins.
With certain exceptions, local public policy up to the
early 70Ts has not faced the water problem squarely. Pro-
jected growth in population and irrigation development,
anticipated for the late 60's did not fully occur in all
areas; however in areas of the County where it occurred
and carried over into the 70's, overdrafting and mining
of the local groundwater supply has resulted. To citizens
of these areas, such activities provide a false sense of
security regarding the permanence and reliability of their
groundwater resources. As long as water can be imported
from elsewhere, water conservation and quality objectives
are overlooked. There is a need for consumer education.
The problem of water conservation and quality is not
limited to the Central Coast region4. Indeed for years
California water resources have been managed for their
utility expecially for consumptive uses. In 1968-69,
for example,76 water treatment facilities, each with design
capacities greater than one million gallons daily (m.g.d.)
serviced 90% of the population of 8 coastal Southern
California counties. Yet only 3.8% (45,000 acre-feet) of
397
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the total wastewater discharged from these plants were
reused for irrigation of crops and/or recreational parks,
or for planned groundwater recharge. The remainder was
used only once before its discharge directly into the
Pacific Ocean (84%) or variously disposed onto land or
into fresh water streams (12.2%) .
As recently as June, 1971. the same memorandum report of
the California Department of Water Resources stated that,
for the immediate future, the areas of San Luis Obispo
County served by four of the five large capacity coastal
wastewater plants had an abundant supply of local, low-cost
water of good quality, and therefore "increased use of
treated wastewater.... is not probable"5.
. *
A
*T
HI VOMO,
MAIN LEVEL
Figure 4. Concept of a polycultural wastewater reclama-
tion aquaculture unit designed by architecture student
Greg Gill. Simple concrete structure built into slope of
rock outcrop at foot of reservoir. Basic design of
hatchery implies water issuing forth from "womb of
earth" where embryonic fish are hatched, reared and
tually grow large enough to exit the hatchery into the
external raceway culture units.
393
-------
But times and attitudes have changed. Increases in popu-
lation and per capita water consumption, coupled with an
increased environmental consciousness, have led to increa-
sing pressure for well-planned and controlled growth
statewide. The Regional Water Quality Control Boards
across the state have initiated a series of watershed
basin studies which, when completed, will result in com-
prehensive water quality plans for each of 16 sub-basins.
In the San Luis Obispo County coastal sub-basin, the
interim plan of 1971 called simply for the discontinuance
of effluent discharge into surface fresh waters before
1980^. The recommended plan now specifies land disposal
with reclamation and reuse for all but two treatment
plants?. In these two exceptions, better ocean outfalls
are proposed but reuse and reclamation projects are still
listed as potential alternatives.
Three years ago, substantial increases in overall agricul-
tural irrigation development were not expected to occur
within the county. Considerable increases in local citrus.
avocado and wine grape acreages however have occurred. For
example, along the coast an 8-fold increase, from 650 acres
in 1970. to 5340 acres by the year 2000, is projectedS.
Similar increases are already occurring inland in The Upper
Salinas Valley watershed with approximately 1600 new acres
of vineyards in the past two years.
It is increasingly apparent, from the regional as well as
local point of view, that as development of additional
agricultural and urban land occurs, however well-controlled,
some means of providing supplemental water, other than by
importation, must be explored. Wastewater reclamation and
reuse should have a high priority among them.
It has been said that wastes are resources out of place.
In San Luis Obispo County, fully one-half of the 25,000
acre-feet of supplemental water needs projected for the
year 20008 could potentially be met by reclaiming the
relatively high quality wastewater being discharged from
eleven existing secondary treatment plants (Table 1). The
polycultural wastewater reclamation concept at Cal Poly
evolved in part out of recognition of this economic and
political reality.
But environmental forces were also at play. In 1971, one
of the guidelines set by the Interim Water Quality Manage-
ment Plan was that there shall be no effluent discharged
into areas which possess unique or uncommon cultural,
scenic, aesthetic, historical or scientific value6. Morro
Bay, one of the least modified major estuaries on the
394
-------
California Coast, is recognized as such a unique place. So
it was that in early 1971, the Central Coastal Regional
Water Quality Control Board gave notice to the California
Department of Corrections, that the California Men's Colony
treatment plant would eventually have to stop discharging
into Chorro Creek, which flows into the Morro Bay estuary.
Fortuitously, at about the same time that the CMC received
notice to consider land disposal of its effluent, officials
of California Polytechnic State University, were becoming
aware of production capacity problems in the two 200 +
g.p.m. irrigation wells located on its Chorro Creek Ranch
property. The university property consists of some 600
acres of valley floor adjacent to and downstream (west)
from the prison's treatment plant (Fig.l). An interagency
agreement was entered into on January 1, 1972 between both
State agencies. Cal Poly was to take all it could use of
the CMC wastewater effluent for land storage and agricul-
tural irrigation. The remainder would still discharge into
Chorro Creek.
Construction of a 50 acre-foot capacity reservoir was soon
scheduled and the decision was made to build it the "Cal
Poly way", i.e., with student class help under the direc-
tion of the instructional staff and faculty. The mechanics
of building a new reservoir soon became intermingled with
new ideas for aquaculture and catfish farming being in-
vestigated elsewhere on campus (see above). The process
opened up the educational experiment described in the
Introduction. It has already involved untold hours of
labor from some 150 students and at least 25 faculty and
staff members in 10 different instructional departments
on campus. Four of the seven academic schools have been
involved thus far.
SYSTEM DESIGN, FACILITIES AND PROPOSED STUDIES
Treatment Plant
The California Men's Colony wastewater facility is a
secondary treatment plant consisting of barscreen, primary
settling, biofilters, secondary settling, chlorination and
sludge digestion apparatus. Design capacity is 1.5 m.g.d.
Current average volume is 0.57 m.g.d. (Table 1). Average
temperature of the effluent at discharge is 7QOF. The CMC
plant is located off State Highway 1, about halfway between
the cities of San Luis Obispo and Morro Bay (Fig.l). It
services the staff and prisoners of the Men's Colony, the
staff and students of Cuesta College, and the staff of Camp
San Luis Obispo (Army National Guard). There are no
395
-------
Table 1. Current Disposition of Secondary Waste Water from San Luis Obispo County
Treatment Plants*
to
DESIGN AVERAGE3
PLANT LOCATION CAPACITY DISCHARGE
(m.g.d.) (m.g.d.)
Coastal
Cambria u.^o
San Simeon 0.15
Cayucos/Morro Bay 1.70
California Men's Colony 1.50
San Luis Obispo 5.00
South County San. District 2.50
Pismo Beach 1.00
Upper Salinas Valley
San Miguel u.ao
Paso Robles 2.20
Atascadero 0.83
Atascadero State Hospital 0.50
TOTALS 15.93
0.06C
0.05°
1.10C
0.57^
3.99e
1.02s.
0.30f
0.30C
1.06e
0.54C
0.14C
8.86
a. Annual totals divided by 365
b. PP - Percolation Ponds; EP - Evaporation Ponds; SI
Freshwater Stream; OO - Ocean Outfall
c. Period January 1973 - December 1973
d. Period August 1972 - July 1973
e. Period July 1972 - June 1973
f. Period July 1971 - June 1972
* Basic data compiled from Central Coastal Regional
files, San Luis Obispo
AVAILABLE
RECLAMATION
(a.f./yr.)
67
56
1232
638
4368
1142
336
34
1187
605
157
9822
TYPE OF
EXISTING
DISPOSAL13
PP, SI
00
00
FS
EP,SI,FS
00
OO
PP
PP,FS
PP,SI,FS
SI
= Spray Irrigation; FS =
Water Quality Control Board
-------
industrial contaminants in the system, the prison laundry
being the only source of sewerage in commercial proportions.
Chlorinated effluent of relatively good quality (Table 2)
is discharged into Chorro Creek and it flows into Morro
Bay estuary, about 4 miles to the west. Some percolation
into the groundwater basin occurs. The City of Morro Bay
obtains a portion of its domestic water supply from wells
in the Chorro Creek basin downstream from the CMC discharge.
These wells and others in the basin have been monitored
over a period of years (Table 3)9. The maximum degre-
dation of ground water shown in the tables has been the
result of occasional sea water intrusion rather than from
CMC effluent percolation.
Biologica1 Treatment Lagoon (BTL)
Wastewater discharging from the CMC plant will be lifted by
a 450 g.p.m., 15 h.p. pump some 60 feet in elevation and
transported via a 6" P.V.C. pipe over a distance of 1500
feet to the newly-constructed 50 acre-foot capacity reser-
voir (Fig.l). There, primarily high nitrate uptake
forage crops will be grown hydroponically in trains of
floating racks. The young shoots of various grasses will
be fed to campus livestock. A greenhouse will also be
constructed for more controlled hydroponic experimentation.
Aquaculture Unit (AU)
Water from the BTL will flow by gravity directly to an
existing 10 acre-foot capacity irrigation reservoir
(Fig.Id) and/or through an experimental aquaculture unit
of a design similar to those illustrated in Figures 3 and
4. The AU will consist of an experimental hatchery and
dry labs, a parallel raceway system, and a series of small
0.1 acre ponds.
Experimental Hatchery - This will provide wet lab facili-
ties for artificial spawning, hatching and rearing of warm
or cold water fishes (Figs.3,4). .Initial experimentation
will utilize channel catfish, Ictalurus punctatus, with
which we have had the most experience, and also the hitch,
Livinia exilicauda, a native herbivorous fish from the
Central Valley. We also hope to raise fresh water clams
and local crayfish.
Dry Laboratory - This portion of the ru will feature a
water and soil quality analysis lab (Figs.3,4). Computeri-
zed, remote multi-channel sensing equipment (Montedoro-
Whitney Corp., San Luis Obispo) will allow continuous or
397
-------
Table 2. Mineral Analysis and Effluent Characteristics,
California Men's Colony Secondary Treatment Plant.
Characteristic
PH
ECxlO^SOC (mmhos/cm)
Total Dissolved Solids f
Total Hardness (asCaCO;)
Total Alkalinity
Calcium (Ca)
Magnesium (Mg)
Sodium (Ha)
Potassium (K)
Iron (Fe)
Carbonate (CO;)
Bicarbonate (HCOj)
Sulfate (SOJ»)
Chloride (C1)
Nitrate (NO;)
Fluoride (F)
Orthophosphate (P0t»)
Boron (B)
B.O.D. Annual Mean (ppm)
B.O.D. Annual Range (ppm)
D.O. Annual Mean
Sol ids, Suspended (ppm)
Solids. Settleable (ml/1)
Grease
Turbidity (JTU)
Col iform (mpn)
1970
7.6
-
672
300
255
28
56
108
8.0
0.21
0
255
32
158
17
3.0
21
0.19
-
-
-
12.4
b
1971
7.7
-
955
384
458
22
59
160
9.2
0.10
0
458
53
233
50
3.9
4.0
0.4
-
-
-
5
1972
7.8
1300
-
342
-
29
66
190
5.4
0.14
0
318
66
291
11
1.8
14.6
1.36
6.0
4-7
7.1
40
d
1973
7.6
1500
1040
325
370
18
59
205
9.0
-
0
370
58
258
18
1.3
14
0.25
9.8
8-13
7.2
9
e
1973
8.2
.
90S
416
377
21
88
197
10
-
0
-
44
243
21
2.4
-
-
-
-
-
-
<0.1 <0. 1 <0. 1 <0.t
1.3
-
<45
1.4
-
<45
a. CMC Ann. Report. Regional Water Qual
c'. " " "
6.8
9.5
<45
ity Control
11
M
3-6
25
<45
Bd.
-
-
-
Feb. 16
June 1 1
July 18
d. ' " " " " " July 11
e. Regional Water Qua 1ity Control Bd.sample obtained June 27
f. Constituents listed in mg/1 unless otherwise specified.
398
-------
Table 3. Summary of Selected Mineral Constituents in
Component Portions of Chorro Creek Basin Water3.
No. Analyses
No. Wells Tested
Mg Avg .
(Range)
804 Avg.
(Range)
Cl Avg .
(Range)
NOs Avg.
(Range)
B Avg.
(Range)
TDS Avg.
(Range)
EC x 106 6 25°C
Avg.
(Range)
SURFACE
WATER
12
68
(27-103)
31
(0-59)
43
(19-77)
4.1
(0-9.9)
0.09
(0-0.20)
433
(234-704)
685
(347-1080)
GROUND
WATER
90
23
114
(9-436)
104
(14-788)
254
(45-2559)
14.5
(0-105.0)
0.13
(0-0.71)
1022
(547-5402)
1643
(990-8264)
CMC
EFFLUENT
16
91
(29-589)
272
(114-865)
23
(0-98.0)
1045
(766-1997)
a. Abstracted from Tables 9, 10,. 14 - Reference No. 9
399
-------
periodic monitoring of several water parameters at critical
locations in the circulation pathway, including monitor
wells around the crop irrigation area. Additional facili-
ties will include large capacity aquarium units with room
for observation of the natural reproductive behavior of
catfish and other warm-or coldwater species. A pathology
lab will be set up for studying and monitoring fish dis-
eases and to investigate the transmission of microbial
pathogens from the effluent water.
Since one of the functions of our project is to educate the
public, the architectural design takes into consideration
not only the needs of the students and faculty, but also
the visitor. Guided or self-guided tours of the facilities
will be designed to educate without disrupting routine
operations.
Irrigation Reservoir
Wastewater from the BTL and the AU will exit to the 10
acre-foot capacity irrigation reservoir (Fig.Id). Outflow
water from this storage site will be used to irrigate field
crops in the crops area west of the reservoir site (Fig.le).
Crops Area
The areal geology of the location indicates an upper
Pleistocene alluvium of sand, gravel and clay. The slopes
and mounds are of Jurassic Franciscan formation consisting
of sedimentary and igneous rocks. The creek terrace soils
are high in clay content with low permeability and slow
rate of infiltration.
Studies similar to those done at the Penn State University
Waste Water Renovation Project10 will be undertaken.
Faculty and students from the Soils Science Department will
analyze soils and monitor the crops area before, during and
after effluent is utilized for irrigation purposes. Deep
cores will be taken and test plots utilizing wastewater
will be compared with those using well water.
Faculty and students from the Crops Science Department will
study yields and quality of field crops under irrigation
with wastewater and well water.
Sludge collected from the fish raceway system will be
analyzed and utilized as fertilizer or for methane gas
generation. Sludge from the CMC treatment plant will also
be evaluated for its potential fertilizer value. Ter-
restial and hydroponic crop wastes not otherwise utilizable
will be composted along with sludge.
WO
-------
Additional Studies
Utilization of Other Wastes - High protein content fish
carcasses,from the Morro Bay commercial fisheries, are
currently being disposed of by land burial. We propose
to convert this valuable waste into fish meal. We will
combine this with high protein material gathered from
terrestial or hydroponic crop wastes. Aquatic crops of
Wolffia or Lemna spp., which are indigenous to our county,
will also be propagated in our ponds. With an appropriate
vitamin mix added, we intend to produce a viable pelletized
fish food at our campus feed mill. With formula variations,
we hope to use it for other campus livestock.
Irrigation and Erosion Controls - Faculty and students from
the Agricultural Engineering Department will design the
irrigation systems, erosion control systems and the overall
hydraulics of the system.
Solar Heating - Faculty and students from Architecture and
Environmental Engineering Departments will design a roof
or wall panels for the aquaculture unit which will feature
solar powered heating of either well water or wastewater
for experimental use in the hatchery.
Food Processing - Faculty and students in the Food Indus-
tries Department will study the technology of processing,
packaging and freezing fish products.
We hope to make our polyculture farm a truly multi-
disciplinary educational unit where faculty can conduct
research, where students can learn by doing, and where
the general public can be exposed to graphic examples of
necessary technologies.
CONCLUSIONS
We believe it is possible to make a resource out of waste-
water by routing it through a series of aquatic and ter-
restial biotic filters. We believe that known methods of
hydroponic culture, aquaculture and agriculture can be
combined into a polycultural process which is not only
economically feasible but also ecologically desireable.
Furthermore, it is our responsibility as educators not
only to teach our students but to educate the public at
large.
SUMMARY
Only a small percentage of secondary wastewater is being
407
-------
reclaimed or reused in Southern California.
Regional Water Quality Control Boards have adopted a policy
of disposal on land for reclamation or reuse with a goal of
substantially reduced ocean outfalls.
It is suggested that wastewater reclamation and reuse
should have high priority among alternate means of supplying
supplemental water in San Luis Obispo County, especially
in areas where overdrafting and mining of ground water has
occurred. There is a need for considerable consumer edu-
cation.
The Cal Poly project will utilize secondary effluent from
the California Men's Colony wastewater treatment plant to
grow harvestable crops hydroponically, aquaculturally and
agriculturally. It is designed for applied research,
student training and public education.
The aquaculture unit wet labs will facilitate the study of
reproductive behavior, hatching and rearing of warm or
cold water fishes. The dry lab portions will be equipped
to study pathology of fishes and other organisms growing
in the secondary effluent. Comparative analysis of soil
and water will occur and remote monitoring of both will be
possible at various critical points in the circulation
pathway.
The student-teacher interaction is a vital component of
this interdisciplinary academic instructional system at
Cal Poly.
1. Thuresson, Neil M. Backyard Polyculture. Senior Project,
Animal Science Department, California Polytechnic State
University, March, 1973, 48p. On file at CPSU Library.
2. Olson, Robert J. Density Factors in Cage Culture of
Channel Catfish, Ictalurus punctatus (Rafinesque).
Senior Project, Biological Sciences Department, Cali-
fornia Polytechnic State University, July, 1972. On
file at CPSU Library.
3. Kupadakvinij, Keith and Dennis Scott. A Catfish
Hatchery for Cal Poly. Senior Project, School of
Architecture and Environmental Design, California
Polytechnic State University, June, 1972. 16p. +
plans on file in School of Architecture Library.
402
-------
4. California, State of, Department of Water Resources,
Wastewater Reclamation, State of the Art. Bulletin
No. 189, March, 1973, 43 p.
5. California, State of, Department of Water Resources.
Southern District. Overview of Wastewater Reclamation
in Southern California, Study Progress during 1969-70.
Memorandum Report, June, 1971.
6. California, State of, Central Coast Regional Water
Quality Control Board, Interim Water Quality Manage-
ment Plan, Central Coast Basin, 1971.
7. Brown and Caldwell, Water Resources Engineers, Inc.,
and Yoder-Trotter-Orlob and Associates. Briefing on
San Luis Obispo Coastal Sub-Basin Recommended Water
Quality Control Plan. Comprehensive Water Quality
Control Study, Central Coast Region, August, 1973.
8. CDM, Inc., Environmental Engineers, Summary Report,
Master Water and Sewerage Plan, County of San Luis
Obispo, October, 1972 as adopted and amended by Board
of Supervisors, November, 1972.
9. California, State of, Department of Water Resources,
Southern District, Water Quality Conditions in
Coastal Regions of San Luis Obispo County. Memorandum
Report to Central Coastal Regional Water Quality
Control Board, October, 1969.
10. Parizek, R.R., L.T. Kardos, et al, Waste Water Reno-
vation and Conservation. Penn State University
Studies, No. 23, University Park, 1967, 71 p.
403
-------
PART 7 ADDITIONAL PAPERS CONTRIBUTED FOR PUBLICATION
-------
COLIFORM AND PHYTOPLANKTON STUDIES IN A BRACKISH WATER
AQUACULTURE POND FERTILIZED WITH DOMESTIC WASTEWATER
by
Robert F. Donnelly and Tommy T. Inouye
INTRODUCTION
Two aquaculture ponds, of about 0.15 hectares each, were constructed
within the confines of the City of Arcata sewage lagoon, located at the
north end of Humboldt Bay, California. These two ponds were placed in
operation June 1971. One pond (designated North Pond) was the experi-
mental site and was filled with a 50-50 mixture of seawater and sewage
effluent from the sewage lagoon. The other pond (designated South Pond)
was filled with seawater only and used as the control in some experi-
ments. Funding for construction of the ponds came from the Wildlife
Conservation Board of California and operating monies were provided by
the California State University, Humboldt, Coherent Area Sea Grant Pro-
gram of the National Oceanographlc and Atmospheric Administration, U.S.
Department of Commerce.
No standards were available for sewage-seawater pond discharge; there-
fore, the Public Health Service indicated that a minimum of 2 weeks re-
tention was needed in the North Pond before the water could be dis-
charged into Humboldt Bay without chlorination. As a result of this
and other considerations, it was decided that one of the authors (Rob-
ert Donnelly) would conduct a study of the coliform levels of the two
ponds, the sewage lagoon itself, and Humboldt Bay, adjacent to the aqua-
culture ponds. Concurrently, Tommy Inouye undertook a study of phyto-
plankton identification and enumeration of the same water samples used
for coliform determinations. At the same time, six other variables,
(pH, DO, salinity, temperature, Secchi disc readings, and depth), were
collected. Due to the large number of samples collected (192), only
the 48 samples from the North Pond were analyzed for their phytoplank-
ton content.
This paper discusses.the possible interrelations among these variables.
Several authors, » » » » have demonstrated relationships between
phytoplankton and bacteria. The bacteria break down organic material
and make it available for phytoplankton utilization and, in turn, the
Donnelly - Fisheries Research Institute, University of Washington,
Seattle, Washington 98195
Inouye - School of Natural Resources, California State University,
Humboldt, Arcata, California 95521
-------
phytoplankton give off organic materials and contribute dead cells to
the bacterial substrate. Some of our data appear to support this cycle.
MATERIALS AND METHODS
LOCATION AND TIME OF SAMPLING
Concurrently, samples of coliforms and phytoplankton were taken from the
North Pond during two different seasons of 1972 (April 15 through May 27
and September 27 through October 31). Collections were made adjacent
to the pond outlet (headgate) six times during each season at approxi-
mately 1-week intervals. Four depths were sampled each time. The sur-
face sample was actually 20 cm below the surface, while the bottom sam-
ple was taken 10 cm above the bottom. The two intermediate sample depths
were equally spaced between these surface and bottom depths. The water
level fluctuated due to rain and evaporation, resulting in different ab-
solute sampling depths each week.
SAMPLING DEVICE
The sampling device consisted of a 500-ml aspirator bottle, a sterilized
and partially evacuated 125-ml bottle, each attached to a long handle,
(Figs. 1, 2, and 3).
Five ml of water and a few boiling chips were placed in each 125-ml sam-
ple bottle. The bottles were stoppered with foam stoppers. Rubber stop-
pers of appropriate size were drilled to accept a Pasteur pipette. The
Pasteur pipettes were bent and flame closed, and then inserted into the
rubber stoppers (Fig. 1).
The rubber stoppers with the bent Pasteur pipettes and foam-stoppered
bottles were autoclaved. After sterilization, the bottles were placed
over a flame and the water within was allowed to boil for a short period
of time. The bottles were removed from the flame and, using aseptic
technique, the rubber stoppers with bent Pasteur pipettes were inserted
into the mouth of each bottle. These were allowed to cool, creating a
partial vacuum. Experimentation showed that these partially evacuated
125-ml bottles would obtain a sample of about 90 ml when the bent Pas-
teur pipette was broken beneath the surface of the water. The inside
diameter of the Pasteur pipette (about 5 mm) was small enough so that
the sample water was held within by surface tension.
The aspirator bottle was controlled through a small plastic tube running
from the top of the bottle to the operator. The sterilized 125-ml bot-
tle was activated by an attached pole struck by a hammer (Fig. 3).
405
-------
Kt Dili If
W$l[«l
12S«I MTILE
*» ink
IUIICI SWKI-tintf
Sterilized. Evacuated SAMPLE BOTTLE
& COMPONENTS
Figure 1. 125-ml sterilized water sample
bottle (complete) bent Pasteur
pipette and bored rubber stopper,
TREATMENT OF THE SAMPLES
Water collected with the aspirator bottle was used to determine DO, pH,
salinity, and temperature at the sample site. The 125-ml samples were
processed at the laboratory where approximately 35 ml of each sample was
inoculated into the nine-tube MPN test for coliforms. The coliform de-
terminations were made according to the procedure outlined in Standard
Methods. One Secchi disc measurement was taken on each day sampled.
The remainder of the 125-ml sample was inoculated with iodine (1 drop
406
-------
•ALUMINUM ANGLE
BRASS ROD - MwutU
RUBBER IANO
SEINE TWINE
BAR I SPRINGS
GUIDE RODS
3mm HOLE
RUBIER (AND
-ALUMINUM BACK PLATE
SAMPLING DEVICE for ACTIVATING
Sterilized, Evacuated Sample Bottle
Figure 2. The device used for activating the
sterilized and partially evacuated
125-ml bottles.
per 10 ml of sample) for phytoplankton identification and counting.
This was accomplished with an inverted microscope and hemocytometer
counting chamber.
RESULTS AND DISCUSSION
The data were analyzed by BMD02R computer program in two ways: 1) by
6-week time periods, and 2) some of the 12-weeks of data were pooled and
analyzed. The first 6-week sampling period included a period after the
sewage-seawater mixture had been in the North Pond for approximately
2.5 months, while the second 6-week period started 2 days after a sew-
age-seawater mixture was introduced into the pond. The coliform levels
407
-------
r tr r
mrted it 10 en
. : . . :: •
IUIEEI TUH
HAMMER
MTIYATINS KOO
v...<
STUUUUI. EUCUTQ
SAMPLE lOITtE
;. • : .
SUBSURFACE SAMPLER
with all COMPONENTS
Figure 3. Assembled apparatus for
obtaining subsurface
water samples.
remained fairly low during the first period, while the levels started
high and decreased until more water was added from Humboldt Bay during
the second sampling period (Fig. 4).,. Humboldt Bay generally had higher
coliform levels than the North Pond.
This second period is of interest because we wanted to know what was oc
curring in the water column during the time the pond was undergoing its
greatest developmental changes. After the pond had stabilized, large
fluctuations in organism populations no longer occurred.
Three genera of phytoplankton were found: Anacystis, Ankistrodesmus,
-------
:
2500
9 10
Sampling week
L;
•-.
...-o-•
• •'' ' Ai.acystis
Figure 4. Anacvstis numbers, coliforms levels, Secchi disc readings
and Ankistrodesinus numbers (averages of the four depths)
during the second sampling period from September 27 to
October 31, 1972. Note the sharp rise in coliform levels
from week 10 to 11 is apparently due to an injection of
Humboldt Bay water on October 23.
and Gymnodinium. with Anacystis being most abundant and Gymnodinium
least numerous. A negative correlation existed between coliform
levels and Secchi disc measurements and between coliform levels and
Ankistrodesmus numbers (Fig. 4). A positive correlation existed be-
tween coliform levels and Anacystis numbers (Fig. 4). All other
variables showed no significant correlation.
409
-------
CONCLUSIONS
The data appears to support the hypothesis that there is a direct rela-
tionship between Anacystis and coliforms. However, a negative correla-
tion existed for Ankistrodesmus and coliforms. One study demonstrated
that bacteria utilize the organics secreted by phytoplankton. In an-
other study, phytoplankton was shown to utilize inorganic nutrients gen-
erated from bacterial breakdown of organic materials in lakes. This
leads us to believe that there may be a nutrient interrelationship be-
tween Anacystis and coliforms.
ACKNOWLEDGMENTS
We wish to thank Dr. George H. Allen for continued support and direction
and Dr. Stephen B. Mathews for assistance with the analysis of the data.
Also, we thank Dr. Ernest 0. Salo and Mr. John S. Isakson for reviewing
the manuscript.
470
-------
LITERATURE CITED
1. Allen, G. H., G. Conversano, and B. Colwell. A pilot fish pond sys-
tem for the utilization of sewage effluents, Humboldt Bay,
Northern California, Mar. Adv. Ext. Service. Sea Grant Pro-
gram, CSUH: CSUH-SG-3. 1972.
2. Kuentzel, L. E. Bacteria, carbon dioxide, and algal blooms. J. Wa-
ter Pollution Control Fed. Vol. 41: 1737-47. 1969.
3. Saunders, G. W. Carbon flow in the aquatic system. In; Carins,
John Jr. (ed.) The structure and function of freshwater mi-
crobial communities. The American Microscopical Society Sym-
posium. Blacksburg, Virginia, pp. 31-45. 1969.
4. Saunders, G. W. and T. A. Storch. Coupled oscillatory control mech-
anism in a planktonic system. Nature New Biology. 230(10):
58-60. 1970.
5. Schegg, E. Relation between plankton development and bacteria in
Lakes Lucerne and Rotsee. Schweiz. A. Hydrol. 30:289-96 (ci-
ted in Biol. Abst. 1970).
6. Donnelly, R. F. A study of coliform levels in aquaculture ponds us-
ing reclaimed water. M. S. Thesis. California State Univ.,
Humboldt. 76 pp. 1973.
7. Standard Methods for the Examination of Waste and Waste Water.
Taxas, M. J., A. E. Greenberg, R. D. Hook, and M. C. Rand
(eds.) Amer. Public Health Assoc., 13th ed., Washington, D.C.
874 pp. 1971.
477
-------
MINERAL QUALITY OF FISH POND
EFFLUENT RELATED TO SOIL
PROPERTIES AND CROP PRODUCTION
by
L. H. Hileman*
INTRODUCTION
Commercial fish production in Arkansas is a $21,000,000 industry
and a steadly growing enterprise. Catfish are efficient converters
of feed into edible meat high in protein, therefore, a valuable
source of human food. Farm production is carried out in earth
ponds varying in size from 10 to 20 or more acres usually filled
with water pumped from underground aquifers. Where adequate
water is available the fish are grown in a system of flumes referred
to as raceways which allows for continous water movement. Water
from these catfish production areas, whether ponds or raceways,
is considered as waste water. A large amount of this waste water
is discharged into streams, and rivers. Enforcement of regulations
pertaining to the discharge of water into streams and rivers caused
fish farmers to consider other methods of disposal. A logical consi-
deration would be the use of this waste water for crop irrigation. A
large number of catfish farmers also grow other food or fiber crops
such as soybeans, rice or cotton. Previous water analysis parame-
ters were concerned with quality factors affecting municipal or in-
dustrial uses. The use of waste water for irrigation may have little
direct effect on the growing crop but can drastically effect soil chem-
istry thus, indirectly affecting crop production over a long period of
time. Certain irrigation water quality parameters will be discussed,
and also data obtained from the chemical analysis of catfish waste
water related to potential effects on the soil and plant growth.
* Agronomy Department, University of Arkansas, Fayetteville, Ark.
** Part of this work was supported by the Cobb Breeding Corp.
Concord, Mass, and Siloam Springs, Arkansas
472
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RESULTS AND DISCUSSION
Irrigation water quality is determined by the kind and amount of
mineral elements present in the water, and the relationship of these
elements to the soil's chemical and physical properties as they affect
both immediate and future crop production. Frequently, in practice
the major concern is with the immediate effect on the growing crop
while the most damaging to the farmer are the long term effects on
the soil. Emphasis in this paper will be placed on the long term
effects on the soil and their relationship to plant growth.
Data in Table 1 shows some of the important parameters for deter-
mining the quality of water for irrigation. Water containing relatively
high amount of calcium and magnesium when applied to soils will, in
time, cause a condition known as a saline soil. A saline soil is one
that is high in soluble calcium and magnesium. Such soils are "salty"
due to the accumulation of these salts near the surface. The princi-
pal effect of high soluble salts is to reduce the availability of water
to the plant. A high soluble salt level will also interfer with the
plant uptake of other needed ions such as potassium, nitrogen, and
iron. The calcium and magnesium levels found in catfish waste
water were quite low, (Table 1). It is interesting to note that the
water was initially rather high in calcium and magnesium (5.1 meq/1)
but this level declined rapidly and reached an equilibrium of near 0. 9
meq/1 during the growth period. Average calcium plus magnesium
data for seven locations shows low values indicating that no serious
soil salinity problems would be expected when any of these waters
were used for irrigation.
Irrigation water containing high amounts of sodium creates a very
serious soil problem known as sodic or alkali soils. These soils are
usually strongly alkaline in reaction, (pH 8. 5 to 10.0) dispersed,
almost impermeable to water, and have poor tilth. This results in
reduced plant growth because of inadequate water penetration, poor
root zone aeration and soil crusting. The large amount of sodium in
these soils also interfers with the plants nutrition by preventing the
uptake of potassium, calcium, and magnesium as well as many of the
micro-nutrients. It is almost impossible to reclaim sodic soils that
have restricted internal drainage. Data in Table 1, shows that this
water was very low in sodium through the first six sampling periods
but then showed a decided increase. Sodium values as shown in
Table 1 are not considered high, however, the more important fac-
tor is the proportion of sodium to calcium and magnesium. This re-
lationship is expressed by the S. A. R. and the S. S.P. values which
are shown in Table 1. The S. A. R. or sodium adsorption ratio is
473
-------
high when it exceeds 10.0 for soils with good internal drainage and
above 5.0 for soils with poor internal drainage. The average S. A. R.
for location 1 is 3.4 (Table 2), which is less than 5.0. The S. A. R.
is based on the soil exchange system which may respond differently
under adverse conditions. The soluble sodium percentage, S. S.P.
is the soluble sodium as a percent of the total soluble cations (Ca,
Mg, Na, K) in the irrigation water. S. S.P. values exceeding 60 are
usually considered high for clay soils with impeded internal drainage.
The water from location 1 would be considered useable based on the
S. A. R. while it would be considered unsatisfactory based on the S. S.P.
The author's experience in Arkansas indicates that the S. S.P. is the
more valid for Arkansas soil conditions. Locations 1, 3, 4, and 6
have high S.S.P. values while locations 8, 9, and 10 are much lower,
Table 2.
The data in Table 2 shows the location variation that can occur with
respect to the irrigation quality of catfish production waste water.
The results of indescriminate use of these waters can result in the
alteration of plant nutrient uptake, therefore, altered plant quality,
reduce crop yields, and soil physical and chemical damage. Farmers
planning to use catfish waste water for irrigation should obtain a
chemical analysis and irrigation quality evaluation before applying it
to their soils.
All of us should keep in mind the thoughtful statement of Franklin D.
Roosevelt; "The history of every nation is eventually written in the
way in which it cares for its soil".
474
-------
Table 1, Calcium, Magnesium, Sodium, Bicarbonates,
Total Dissolved Salts, S.A.R. andS.S.P.
Values for Catfish Production Water at Location 1,
1971 for the Two Week Sampling Periods.
Sampling*
1- fill
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Ca+Mg
5.1
1.9
0.7
0.8
1.4
0.7
0.6
0.9
0.7
0.6
0.7
1.1
0.8
0.8
0.7
0.6
0.8
0.9
0,8
0.8
0.8
0.8
0.8
0.8
0.9
0.8
0.8
0.9
0.9
Na
meq/1
0.5
0.5
0.5
0.5
0.1
0.05
3.5
4. 1
3.9
3.6
3.7
3.6
4.0
3.5
0.05
0.5
4.1
0.4
3.9
3.8
3.7
3.5
2.2
1.4
3.2
2.3
2.6
2.7
2.9
HC03
3.8
4.2
4.2
4.3
7.0
4.1
3.8
3.8
3.9
3.6
3.7
3.9
4.0
4.2
4.0
4.3
4.5
3.8
3.8
3.6
3.0
3.2
2.8
3.1
3.5
3.6
3.6
3.1
3.0
T.D.S,
ppm
269
307
294
320
64
282
283
269
269
256
269
269
307
294
307
320
320
269
269
269
243
243
192
256
269
269
243
230
243
S.A. R.
ratio
>1.0
^1.0
1.0
1.1
M.O
1.0
6.8
6.0
6.1
7.1
6.0
>1.0
6.0
5.6
1.0
>1.0
5.8
1.3
6.0
6.1
5.6
5.3
3.8
2.4
4.8
3.8
4.8
4.0
4.6
S.S.P.
%
8.9
20.8
41.6
39.2
6.6
6.6
85.4
82.0
84.8
85.7
84.0
76.0
83.3
81.4
6.6
45.4
83.6
30.7
82.9
82.6
82.2
81.4
73.3
63.6
78.0
74.2
76.5
75.0
76.3
* Samples taken at two week intervals.
475
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Table 2. Average Calcium, Magnesium, Sodium,
Bicarbonate, Total Dissolved Salts, S.A.R. and
S. S. P. Values for Catfish Production Waters
at Several Locations,
Na T.D.S S.A.R. S.S.P.
Location* Ca+Mg meq/1 HCOs ppm ratio %
1
3
4
6
8
9
10
0.99
0.58
0.86
0.53
1.60
1.13
1.60
2.4
4.1
2.7
4.3
0.8
0.5
0.9
3.8
3.0
3.3
2.8
1.9
1.6
2.1
265
405
269
383
221
145
226
3.4
7.6
3.8
9.0
1.0
1.0
1.0
70.6
87.2
75.0
89.6
33.0
31.2
36.0
* 1, 3, 4, and 6 were in the Coastal Plain of Mississippi. Loca-
tions 8, 9, and 10 were in the Mississippi Delta of Arkansas.
476
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THE DIALECTICS OP A PROPOSAL
ON
BIOLOGICAL CONTROL 0? iSUTHOPHICATION IN
SEWAGE LAGOONS
S. T. Lin*
ABSTRACT
The existing lagoons for the deposition, of municipal sewage face
the problems of extreme eutrophication and of the effluents being
highly polluted for discharge into public waters. An elaborate
mechanical engineering plant if established to purify the sewage
water would be very expensive in both initial cost and mainten-
ance. The present proposal is to take the advantages of biolog-
ical control by utilization of natural performance of pure plank-
ton feeding fishes , filamentous algae eaters , bottom feeders and
scavengers to purify the sewage water. It is more economical
this way than any mechanical engineering design. In addition.
biological control has many advantages in fitting in the prin-
ciples of environment improvement and protection and in produc-
tion of animal proteins.
INTRODUCTION
BACKGROUND INFORMATION AND GENERAL CONSIDERATIONS
The formulation of this dialectics is the result of many long
discussions with J. M. Malone Jr., Manager of J. M. Mai one and
Son Enterprises of Lonoke, Arkansas, and after some observations
made on the sewage lagoons in Lonoke and England, Arkansas.
The most common phenomenon in these setrage holding lagoons is the
process of eutrophioation as a result of the growth of phytoplank-
ton which will reach in summer warm days to -the highest level
through the support of the organic and mineral nutrients coming
in with the domes tie sewage. However eutrophication will not
^Former Fisheries Biologist of FAO of the United Nations and
Professor of Fish Culture, National Taiwan University, Taiwan,
China.
477
-------
occur if the domestic sewage is too thick with sludge or mixed
with industrial waste, some substances from which will kill the
algae. Otherwise at the highest level of eutrophication no more
space and dissolved oxygen are available for further expansion^
meanwhile toxic substances secreted by the animals and plants
are accumulated to so high a concentration that the algae and
zooplankton can no longer survive resulting in total death of
most of the biota in the lagoon followed by decomposition to pro-
duce the worst situation of pollution which may last for a consi-
derable length of time before the lagoon can return to suitable
conditions for the growth of phytoplankton again. This is local-
ly known as'a turnover. It is a biological turnover, to be sure,
but it oust be distinguished from the limnological turnovers
during the spring and fall due to thermal difference and wind
action. Under the present circumstances the effluents from many
such highly polluted lagoons are being directly discharged into
public waters.
For this reason alone it is highly desirable if such excessive
eutrophication can be prevented by introduction of certain plank-
ton feeders to graze down the exuberant algae so as to avoid a
turnover and moreover a system of new ponds be built to purify
the effluents through similar biological process. This so far
as dialectics go can be satisfactorily achieved.
While eutrophication is advancing, not only the planktonic algae
are in exuberant bloom but also zooplankton, bottom worms and
algae, snails and insects are thriving to the highest degree of
abundance. So in addition to the introduction of phytoplankton
and zooplankton feeders, omnivores of bottom feeding habit and
even scavengers like common carp and carpsuckers which consume
waste organic matter in suspension and on the bottom are necessary
to be added to the sewage ponds so that a full balanced extent of
biological control can be accomplished. Naturally the fishes so
introduced will produce reasonable amount of organic waste in
the form of faeces, but such excreta which have been partly
digested and fermented in the digestive tract of the fish are
easily and rapidly decomposed by bacteria into simple gases,
water, minerals and soluble organic substances.
Actually what happen in the sewage lagoon and the ponds is a
series of transformations of inorganic components activated by
the energy of the sun in the phytoplankton into organic matter
and then back to inorganic components by animals .and bacteria.
The first transformation, of course, involves the process of
photosynthesis in which th* mineral nutrients are taken up by the
phytoplankton to form organic substances with CO- and H_0 as
475
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basic materials of life. Next come the zooplankton, worms, molluscs
insects and fish to feed on the phytoplankton, but as the popu-
lation of the phytoplankton is so large, these animals can only
consume a small portion of it. In the third phase the large
animals will prey on the small ones. At last when the plants and
animals die their bodies will be decomposed by bacteria to simple
organic and mineral components, HJ? and C02 which the algae will
be able to utilize again.
In the instance when no efficient plankton feeding fishes are
present, the phytoplankton and zooplankton will increase rapidly
to the highest degree with a consequence of total death of the
planktons caused by population explosion shock. But with the
introduction o\ the phytoplankton feeding fishes to graze down
a substantial part of the phytoplankton and to keep the biological
community in balance, a turnover would be prevented as illustrated
in figure 1*
Now let us review some of the information in literature as how
far this principle of biological control has been applied in the
field of fis h culture with the purpose to improve wildlife
environment in rivers and lakes and to increase fish production
in ponds•
REVIEW OF LITBRATUEE
There are many kinds of aquatic animals which feed on planktonic
algae. Oysters, clams and mussels, for example, are efficient
algae consumers. Based on this feeding habit Ryther ejt ad (1972)
envisaged the possibility of using tertiary sewage for oyster
culture under cotrolled eutrophication: He offered a very interest-
ing dialectics in which he suggested that a town of 50,000 people
could, with its 51 ha aqua culture-sewage treatment system, raise
an annual crop of over 900 tons of oyster meat or nearly 90,000
hectoliters (250,000 bushels) of whole oysters worth, in today's
market as a luxury table oyster, upwards to 55 million. But
upon further search of information it is revealed that a certain
fishes because of their large size and free swimming habit may
be even more adequate for the control of phytoplankton. As the
studies of Lin(l969) indicated, the silver amur or silver carp
(Hvpophthaltniohthys. molitrix) and the bighead (Aristichthys nobil is)
which grow to 10 or 15 kgs in a few years under favorable conditions
are pure and efficient plankton feeders. The silver annir because
of its spongy-plate-like gill-rakers that can filter minute part-
iculates in water feeds principally on macrophytoplankton as well
as microphytoplankton, while the bighead with closely set but
separate gill-rakers filters out only the macrophytoplankton and
zooplankton for food.
479
-------
600
5OO
o>
P<
400
300
o
00
•£ 200
•H
8
o
100
•Biological turnover or
total death of phyto-
plankton due to popula-
tion explosion shock
without fish
Pish
satiety
according
to
seasons
Phytoplankton population
under control with fish
Month
Figure 1 - Hypothetical curves of phytoplankton
population trends in sewage lagoon before
( solid line ) and after ( Broken line ) the
stocking of fishes ( double lines ).
H2Q
-------
Mukhamedova and Sarsembayev (1967) found by experiments that
silver carp fry of 1.5 g consumed food equal to 11% of its body
weight and the young of 5.8 g 12^ and Omarov (1970) carried out
experiments further on the feeding patterns of silver carp "weigh-
ing 328 to 3^80 g and revealed that the fish ingested food in 24
hours at 23 C with a DO of 4.23 ml/1 of 19^ of i£s body weight on
the average. At higher temperature (e.g. 26°-30 C) the consump-
tion rate will certainly be increased. Apart from this information
we are not aware so far that there have been any comprehensive
studies on the quantity of plankton being consumed by the silver
carp per unit body weight per day under conditions of different
seasons. Information on the quantitative feeding of the bighead
is entirely lacking.
It has been observed, however, that the grass carp (Ctenopharyn-
godon idella) known as pure herbivore feeding on macrophytes can
consume aquatic weeds 5° to 100 or even 200 ( as claimed by some
fish farmers) per cent of its body weight a day dependent on the
size of the fish and water temperature. This means that a large
fish would eat comparatively more weeds than a smaller one. Here
we may assume that both the silver carp and bighead would consume
phytoplankton 20 to 50 per cent of their weight per day in water
temperature 26 to 30 C. It follows that if a lagoon isstocked
with 3000 kg/ha of the two fishes each more than 500g, then
600 to 1500 kg/ha per day or 120 to 300 tons in 200 days chiefly
of phytoplanlton could be consumed by the fishes a year. It is
estimated that under optimal conditions a freshwater pond or a
sea water lagoon has the potentiality of producing 160 or 200
tons respectively of phytoplankton per ha/year (Tamiya, 1957 and
Ryther et, sd^, 1972). In the case of sewage lagoon if a quarter
to half of this production could be removed, probably a biological
turnover would be avoided and this may be effectively accomplish-
ed by rational stocking with the above mentioned fishes together
with b3a ck carp (Mylopharyngodon p_iceua) and some other bottom
algae and worm feeders such as grey mullet (Mugil cephalus) and
mud carp (Girrhinus molitorella) also.
It is significant that Cyanophyta constitute the major part of
food bolus ( over 60^,) in the digestive tract of silver carp (Lin,
1969 and Chiang, 1971) and for this reason the fish will be an
effective agent for controlling the blue green algae which are
always abundant in the sewage lagoons. In China over two million
ha of freshwater ponds are in existence; many of them were built
centuries ago. Most of them especially those lying in the Bearl
fiiver and Yangtze River deltas are heavily fertilized with dom-
estic sewage, animal manure plus supplementary feeding and are
stocked with silver carp, bighead, grass carp, black carp, mud
carp and common carp (Lin, 1954* Hickling, 1971J and Chinese
427
-------
Pish Culture Experience Committee, 1961). As a result of such
polyculture excessive eutrophication is always placed under con-
trol and consequftntly the so—called biological turnover very
seldom occurs.
The carp pond complex at Munich and Berlin serving as sewage pur-
ification fields is well known (Schaeperclaus, 1961 and Hickling,
1971). After the sewage effluent is diluted "by 3 or 4 to 1 with
freshwater it is sprayed into ponds where the mixed effluent is
purified through natural process and can be safely discharged
into rivers.
The use of undiluted domestic sewage waste water from a sewage
treatment plant at Kielce, Poland, for the culture of Crucian
carp (Caraaaius carassius) with satisfactory results is even
more impressive (fhorsland, 1971)* The effluent from the treat-
ment plant (by activated sludge method but without clorination)
was led into five experimental ponds, three of which were stock-
ad with carp and two as control. Fish yield without supplemen-
tary feeding was up to 1,317 kg/ha, the highest yield ever ob-
tained in Poland. Allen (1970) advocated the constructive use
of sewage water for fish culturej Huggins (1970) and Konefee
(1970) experimented on the use of tertiary treatment ponds to
raise channel catfish and- fathead minnow with encouraging results.
Tsai (1973) studied fish sensitivity in sewage polluted streams
of Maryland with results hinting strongly on the potentiality
of using sewage waste water for fish culture.
OBJECTIVES OP THE PROPOSAL
In trying to solve the problems of eutrophication and that of
the purification of the effluents coming out of the sewage
lagoons it is considered necessary to test the hypothesis or
dialectics in the best practical manner possible and thereupon
it is proposed to initiate a pilot project with the following
objectives in view:
1. The project will be designed to develop different patterns
of fish communities each species in which will perform a
distinct function In controlling a certain element or elements
in the sewage waste water. The combined functions of different
species should eventually result in purification of the sewage
water.
2. It is further designed to test whether aquatic plants in
combination with fishes would enhance the purification
process.
422
-------
3. Meanwhile the feeding habits of the silver araur and bighead
will be studied and determined quantitatively. This know-
ledge is particularly important in forming a basis for stock-
ing rate design.
4. The project would provide sufficient data to show ever more
strongly that sewage waste water constitutes a great potent-
ial source for fish production which could be utilized for
both human and animal food.
A PROPOSED PILOT PROJECT
With the above objectives in view and on the basis of the in-
formation discussed before it appears very feasible that the
experiences and results obtained in the past can be applied to
the management of the sewage lagoons in the United States with
a good chance of success. After a preliminary survey of the
sewage lagoon system in Lonoke and England, Arkansas, we are
convinced that a great deal can be learned from a pilot project
and therefore we strongly feel that a project of this nature
should be started as soon as possible.
SITE FOR THE PILOT PROJECT
It is proposed oo use the sewage lagoon of Lonoke or any other
town or city for the establishment of the pilot project in the
first year. When it proves a success after a period of test,
one or two or even three other lagoons may be selected for next
period's test. In the third period, some three or four years
later, if the results of the first two period's experiments are
satisfactory, work will be extended to as many lagoons as practi-
cal*
The sewage lagoon of Lonoke has a superficie of eight hectares
(20 acres) and a depth of 1.5 meters. It receives an inflow of
domestic sewage at the rate of some 500,000 gallons a day from
a population of 4,000 people. On June 3, 1973 the lagoon was
observed to be at a high level of eutrophioation but not up to
the stage of turnover. Anaoystis and other blue green algae
were abundant; some small fish (probably Q ambus ia) were seen
along the margins of the lagoon and common carp were reported
also to be present.
SIGNIFICANT ADVAHTAQES OF THE PROJECT
Although it would be difficult to make any precise evaluation
of the project at this moment its implementation would obvious-
ly have many advantages: (l) It is an economical project.. The
423
-------
cost of construction and maintenance of any mechanical engineer-
ing sewage treatment plant will be always higher than this pro-
posed "biological control plant. Houghly speaking the establish-
ment of amechanical engineering plant may cost over a million
dollars while that of a "biological control plant will cost only
half or even less as much. The maintenance cost will be also much
more in the engineering plant than in a biological control plant;
(2) if the purification ponds are to be well arranged and con-
structed with roads and trees are planted around, no smell will
be emitted from the lagoon and ponds and such area may well be-
come a suitable spot for recreation purpose; (3) the sewage
purification pond system when well stocked with fish can be open
to public for sport fishing; (4) fish is one of the principal
sources of animal, protein for human consumption. If all the
sewage lagoons in the United States are to be placed under simi-
lar management fish crop would be considerable, which can be
rationally harvested and processed to serve as animal and human
food; (5) the project would turn all the hazards of the domestic
sewage ponds into a natural purification system that would be
in perfect harmony with any balanced environment.
ORGANIZATION AND MANAGEMENT
Any private fish farm in the United States which has the facili-
ties and expertise to propagate and cultivate the silver amur,
the bighead, the black, the white amur and the common carp can
be trusted by contract by a city or town government to manage
the project. Such private fish farm under contract will take
the responsibility to design, develop and maintain the pilot pro-
ject. At the request of the city government the ulnvironment Pro-
tection Agency of Federal Government should subsidize the Pro-
ject by grant funds.
An essential task of the private farm as a managing agent is to
propagate all the fishfls required to stock the biological control
sewage system anfl to replace the fishes after their removal at
harvest able size.
When this pilot project proves a success at the end of a year or
so, it is envisaged that work would be continued and extended
to other city sewage systems under similar working and organi-
zation relationship and financial arrangement between EPA, city
government and the private fish farm as managing agent.
METHODS AND PROCEDURE
CONSTRUCTION OF PURIFICATION PONDS
424
-------
The first step to be taken for the construction of the purifica-
tion ponds is to make a topographic survey of the area concerned
and then basing on the topographic map a pond system will be
designed and constructed.
As a usual practice one hectare of sewage lagoon is provided for
a population of 500 people. For example, for a town of 4,000
people like Lonoke of Arkansas, a lagoon of 8 ha or 20 acres at
200 persons per acre with about 1.5 meter in depth has been
built. Despite the lack of data it is assumed that the concen-
tration of the nutrients in the secondary effluents from the
sewage lagoon ranges quite close to the national average which
shows in micron moles per liter: 242 NO , 1180 SH , 264 PO ,
and 656 SiO (Ryther «t jal, 1972). Concentration of such level
is, of course, still too high for discharge into public waters.
In order to reduce the concentration it is propos ed to construct
six ponds each one ha in superficie and two meters in depth,
below the existing sewage lagoon of 8 ha to receive the effluent
for further purification, the proposed arrangement of which is
shown in figure 2.
The superfioie ratio between sewage lagoon and each purification
pond of a system of six in this case is approximately 8:1. How-
ever the exact proportion should be determined in the future by
experience and research.
PROGRAM OP STUDIES
Determination of Hater Quality
The water quality of the sewage lagoon will be studied according
to the Standard Methods for Examination of Water and Waste Water
edited by American Public Health Association, 1971.
After the six ponds are built and filled with sewage water but
before the stocking of fishes, determination of water quality
should be made (of both the lagoon and all the ponds) at least
once a month according to the following criterias
Conductivity, total chlorine, detergent, ammonian nitrogen,
nitrite and nitrate nitrogen, PO , SiO_, Gu, Zn, C02, DO,
COL, BOD, alkalinity, hardness, acidity, turbidity, tem-
perature in air and water, eto.
Water samples will be taken at selected spots as indicated in
figure 2. A 2-liter sampling cylinder will be made for this
purpose.
Sjbudy of Fishes
425
-------
U)
(x)
Sewage lagoon
( 8 ha )
U)
ire
tflow gat a
Inflow gate
tion of water
flow
P4
P6
6 new
purification
ponds
Figure 2 - A sketch showing the existing sewage lagoon
(above) and the air new purification ponds (below)
(X) indicates the selected spot for water quality
and plankton sampling.
426
-------
Observation will be made on the daily movement of the fishes
especially in relation to oxygen contents and their growth rates.
As all the fis hes stocked except the common carp are unable to
spawn in captivity, popuplation study will be a simple matter.
Even the common carp because of the depth of water and polluted
conditions, may not be able to reproduce as well. F'ish samples
will be collected with nets from the lagoon and purification
ponds once every three months during the period from April to
October for weight and length measurements. In each sampling
it is expected to obtain 20 to 50 silver amur, 5 white amur, 5
bighead, 5 black carp and possibly 3 common carp for examination.
Plankton and Benthos.
The same water from samples collected for water quality deter-
mination will be used also for plankton study. Phytoplankton
and zooplankton concentration, identification and number of each
kind per liter will be determined according to limnological
methods. Benthic biomass study will follow the method described
in Hallock and Ziebell (1970).
Bacteria
Attempt may be made to determine whether coliforms are present
at the outlet of pond 6.
Use of Aquatic Plants for Purification
Aquatic plants are to be grown in ponds P5 and P6 for the pur-
pose of testing how effective phosphate and other nutrients left
over would be absorbed by them. The water quality examinations
at tha inflows and outflows of the two ponds will be compared
to determine this effect.
SELECTION OS1 WISHES FOR STOCKING
The fishes as described below all possess the characters that
would meet the biological requirement for sewage waHe water
purification, but the most important common merit to them all
is their, tolerance to low dissolved oxygen, content; they all
thrive fairly well in a DO of 2 to 3 ppmQand would grow well in
4 to 5 ppm at watar temperature about 28 C; they can even sur-
vive for sometime below 1 ppm.
Silver amur - This silver fish is a vary efficient phytoplankton
feeder, fast growing to attain 5 to 10 kg In a few years. It
lives in the upper layer of water, fast swimming, agile, active
and always jumping out of water when disturbed; large fish can
stand lower DO than small ones; a warm-water fish but tolerates
427
-------
temperature "below 4 C. Because of the special spongy structure
of its gill-rakers it can filter out phytoplankton less than
20 microns for food.
Boghead - A slow moving fish but fast growing, attaining large
size up to 10 or 15 kg in a feir years; a 10-pounder of three
years old is not uncommon. The fish has a very large head, hence
its name, and a wide mouth, living in the upper layer of water,
gaping all the time to suck in phytoplankton, zooplankton and de-
tritus for food. A warm-water fish y«y tolerant to water tem-
perature below 4 Cj it survives under ice.
Black carp - A very large fish found in lakes and rivers of
China up to 50 kg but in captivity it usually grows to some
10 kg in a few years. It prefers to live close to the bottom
of deep water so that it oan pick up snails, mussels and crus-
taceans for food.
White amur or grass carp - This fish is well known for its
remarkable ability to consume satiably aquatic weeds, filamentous
algae, land grass and leaves of many land plants. It roams every
where in search of food} a hungry fish will take mixed feedstuff,
meat, pieces of cloth or shoe leather when they are thrown into
the $ond, and yet it prefers fresh, tender vegetable food when-
ever they are available. It attains some 5 kg in three or four
years on vegetable food alone, tolerant to water temperature
below 40.
Common carp - A fish of longivity, perhaps a unique character
among all fishes known; a color carp was recorded in Japan to
live 215 years in a monastery. It inhabits most of the time
near the bottom* sucking up worms and detritus mixed with mud.
Immediately following the sucking the mud is ejected and the
worms and digestible part of the detritus are retained and
swallowed. As a result the bottom soil is thus disturbed and
activated.
FISH STOCKING DESIQHS ?0£ EXPERIMENT
The design is based roughly on the estimates of phytoplankton
production and the eating capacity of the plankton feeders.
There will be designs of different fish communities for any
particular sewage lagoon system.
When the six purification ponds each about one ha in superficie
are built we would have a system of seven ponds including the
sewage lagoon* According to the figufres given by Tamiya (195?)
and Ryther et. al (1972) the sewage lagoon at Lonoke of 8 ha is
capable , as estimated, to produce 1280 tons of phytoplankton
428
-------
a year, about 128 tons of which might be simultaneously convert-
ed to zooplankton. However to simplify calculation we may assume
that the lagoon would produce a total of 1300 tons of plankton
in all ayear or 6.5 tons a day if we count only 200 days a year
as the active production period. Theoretically if all the plank-
ton are to be removed, 13,000 to 32,500 kg of plankton-feeding
fish should exist all the time in the lagoon and they would con-
sume plankton 20 to 5°$ of their body weight.
Evidently it is neither possible nor desirable to deplete the
lagoon of all the phytoplankton by stocking too many fish at
one time, for a considerable quantity of phytoplankton must be
left to do away with the noxious gases, excessive minerals and
organic substances and to provide dissolved oxygen and C0p and
consequently proper pH for the balance of life in the lagoon.
For this reason it is proposed to stock the lagoon with a mini-
mum rate of fish to feed on the plankton or empirically a rate
of 1000 kg/ha or 8000 kg of fish for the whole lagoon of 8 ha,
provided that the DO is sufficient for the fish to thrive.
However, wherever the sewage lagoon is found to be insufficent
in DO, no fish should be introduced and the effluent that flows
into the ^rification ponds should be diluted with freshwater
to improve the conditions for plankton growth and fish life.
Anyhow at this rate of stocking, the silver amur, bighead and
white amur of about 250 g would grow to one kg within a year
which would be sufficient to consume enough plankton so as to
prevent a turnover in the hot summer. As the fish grow and the
lagoon is found overcrowded with fish the big ones should be
removed and small ones introduced to replaced them.
A test fish stocking system of the lagoon and six ponds is
suggested here as shown in table 1 for reference.
This table is given only to indicate a possible system of fish
stocking . Modifications will have to be made when the waters
of the lagoon and ponds are analised with attention being paid
particularly to DO, SH and other poisonous substances. As the
primary sewage waste water is continuously flowing into the
lagoon and out from it carrying plankton at the rate of some
2.5$ of the holding capacity of the lagoon and 10 to 20$ of
that of the purification ponds from one to another, the phyto-
plankton concentration must be accordingly reduced and there-
fore the fish stocking rate should be proportionately lowered.
ADDITIONAL MECHANICAL DEVICES IF N3C2SSARY
It is hoped that by this process of biological purification the
effluent coming out of Pond 6 would be close enough to the EPA
425
-------
standards which stipulate as 30 ppm of BOB, 30 ppm of CO]), 30 ppm
of suspended solids, 200 coliforms per ml and a pH reaction of
9. However in view of the fact that after a considerably long
period the accumulation of solids from the domestic sewage in
the lagoon bottom will be too much for satisfactory functioning
of the biological control system and the plankton and suspended
solids may become higher than the standards, it may be necessary
to consider, first of all, the installation of a sedimentation
system with a fermentation tank (activated sludge method) to
remove the solids before the city sewage is pumped into the
lagoon. This is one part of the common installations in many
mechanical engineering sewage treatment plants.
Table 1. A proposed stocking rate for the Lonoke
sewage pond system
Quantity of each species to be introduced
Lagoon
and Area ———•
ponds (ha) Silver Bighead Black White Common Aquatic
amur carp amur carp plants
Total
fewage
agoon
PI
P2
P3
P4
?5
P6
Grand
total
8
1
1
1
1
1
1
14
6,000
3,500
2,500
1,500
1,000
1,000
500
16,000
1,000
500
500
500
300
200
100
3,100
400
50
50
50
50
50
50
700
200
50
50
50
50
—
— —
400
200
100 —
50
50 —
50 —
— Selected
— plants
450
7,800
4,200
3,150
2,150
1,450
1,250
650
20,650
PROSPECTS 0? FUTURE DEVELOPMENT
According to the records on municipal sevage system of Arkansas
kept in the Department of Pollution Control and Ecology, State
of Arkansas, January, 1972, there were 622,000 people who used
"oxidation ponds" or lagoon for sewage treatment which cover a
total of some 3,110 acres or 1,260 ha . If 945 ha. more ponds
are constructed to purify the effluents from the sewage logoons
as described in the above proposed biological control project
the total area will be increased to 2,205 ha. Country-wide
statistics on sewage lagoons are not available at the moment, but
should similar design be extended to the whole country at the
same rate of one-third of the population or 70 million out of
430
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210 million people, a total of sewage-aquaculture area of
247,350 ha would be required. In this aquaculture system
primarily for the purification of sewage waste waters, if fish
are stocked at the rate as shown in table 1, it would be possible
to harvest a crop of 494,700 tons in total of marketable fish at
the rate of 2000 kg/ha/year.
Objections may be raised against the allocation of land for the
construction of the biological purification system. Some may
think that land is too valuable for such a project and one or
two hectares for every 300 people is excessive. But contra-
dictions exist between clean air and water and the limited space
of land. The urgency for the resolution of such^contradictions
allows us no alternative but to adopt a system Awould be most
economical and fit for maintaining the harmony and balance of
natural environment for human life. It is therefore logical to
argue that if clean air and water are desired sufficient land
space must be provided for nature to work. Moreover consider-
ation must be given to the high cost of establishing and main-
taining a compact chemical and mechanical engineering plant
against that of an economical biological control one. In the
matter of environment protection principle, space is a basic
factor for the maintenance of clean air and water, for unless
sufficient spaoe is allowed for nature to work in oxidation,
reduction, sun energy activating photosynthesis and bacterial
decomposition, all the wastes produced by men and animals cannot
be recycled back to their original harmless components. For
this reason it is not hard for us to realize that in city and
rural community plannings, adequate land space and open air
must be made available and amply reserved for parks, gardens,
forest, recreation fields, roads, houses, hospitals, schools,
sewage waste water disposal, factories and agriculture fields.
When the fact that such planning is closely linked to public
health and environment protection is kept in mind, one would
agree that the provision of one or two hectares of land for the
treatment of domestic sewage of every 300 people is nothing
but a matter of absolute necessity.
REFEREHCES
Allen, Q.H. 1969. A preliminary bibliography on the utilization
of sewage in fish culture. FAO Fish Circ. 308.
lien, G.H. 1970. The constructive use of sewage with particular
reference to fish culture. Constribution to the FAO
Technical Conference on Marine Pollution and its Effects
on Living Resources and fishing. FIRtMP/70/R-13- Rome,
9-18 December, 1970.
437
-------
Chekiang Fisheries Bureau. 1957. Pond fish culture. Finance
and Economics Press, 226 pages.
Chiang, ¥an. 1971. Studies on feeding and protein digestibility
of silver carp, Hypophthalmiohthys molitrix (C.and V.).
JOBS Fisheries Series Ho. 11, p. 96-114.
Chinese Fish Culture Experiences Committee. 1961. Chinese Fresh-
Water fish culture. Science Press, Peking, 612 pages.
Falck, T. 1934- The construction of sewage fish ponds as relief
work. Gresundh. Ing. 57:228 (Abstract on Sewage Work Jour.
1934, 6, 4.).
Federal ¥ater Pollution Control Administration. 1968. Water
quality criteria. U.S. Goveramnet Printing Office, 234
pages.
Hallock, R.J. and C.D. Ziebell, 1970. Feasibility of a sport
fishery in tertiary treated wastewater. Jour. Water Poll
Control Fed., 42(9)«1656-1665.
Hiokling, C.F. 1966. On the feeding process in the white amur,
Ctenopharyngodon idella. Jour. Zool. 148:408-409.
Hickliag, C.F. 1971. Fish culture. Faber and Faber, London,
317 pages.
Huggins, T.£. and S.W. Bachmann, 1970. Production of channel
catfish (Ictulurus punotatus) in tertiary treatment ponds.
U.S. Govt. Res. Develop. Kept. 70(9): 132.
Hynes, H.B.N., I960. The biology of polluted waters. Liverpool
University Press, England, 190 pages.
Katz, M. and A.R. Ganfin, 1952. The effect of sewage pollution
on the fish population of a midwestern stream. Trans. Amer.
Fish. Soo., 82:156-165.
Konefes, J.L. and R.¥. Bachmann, 1970. Growth of fathead
minnow (Pimephales promelas) in tertiary treatment ponds.
Proo. Iowa Acad. Sci., 77:104.
Kraus, Harjorie, 1971. Molecular process in lagoon management.
Remarks made at Chester County Commissioner's Symposium
on Lagoons. Holiday Inn, Lionville, Pa., 2 pages.
432
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Lin, S.Y., 1940 • Pish, culture in ponds in the Hew Territories
of Hong Kong. Jour. Hongkong Fish. Res. Sta., 1(2): 161-
163.
Lin, S.Y., 1954* Chinese systems of pond stocking. Indo-Pacif ic
fisheries Council Proceedings, p. 65-71.
Lin, S.Y., 1969. The feeding habits of silver carp, bighead
and mud carp. JCHB Fisheries Series No. 8, p. 49-66.
Mckee, J.E. andH.¥. Wolf, 1963. Water quality criteria. Calif.
State Water Quality Control Board Publ. 3-A, 548 pages.
Mukhamedova, A.F. and Zh.G. Sarsembayev , 1967. On the daily
feeding pattern and food consumption of underyearling
silver carp. Tr. Volgogradskogo otd. Cos. N.-i. in-ta
Ozern. 1 reohn. rybn. kh-va, _3_.
Omarov, M.O., 1970. The daily food consumption of silver carp,
Hypophthalmiohthys molitrix (Val.). Jour, of Ichthyology,
10( 3) » 425-426.
Prowse, O.A., 1969. The role of cultured pond fish in the con-
trol of eutrophxcaTion in lakes and dams. Verh. Internat.
Verein., 17:714-718.
Ryther, J.H., 1959* Potential productivity of the sea. Science,
130:602-608.
Ryther, J.H., W.M. Duns tan, K.R. Tenore and J.S. Huguenin, 1972.
Controlled eutrophication - Increasing food production
from sea by recycling human wastes. Bioscience, 22(3):
144-151.
Ryther, J.H. and W.M. l)unstan, 1971- Nitogen, phosphorus and
eutrophication in coastal marine environment, Science,
171:1008-1013.
Schaeperclaus, W., 1961. Lehrbuch der teichwirtschaf t. Verlag
Paul Parey, Berlin, 582 pages.
Tamiya, H., 1957. Mass culture of algae. Ann. Rev. Plant
Physiol., 8:309-334.
Thorsland, Anders B., 1971. Potential uses of waste waters and
heated effluents. EIPAC Occ. pap., (5): 23, p. 1-7.
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Tsai, Chu-fa, 1973- Vater quality and fish life below sewage
outfalls. Trans. Amer. Pish. Soc., 102(2):281-292.
Willis, Duddley, 1970. A talk on effective, inexpensive, proven
method of recycling human waste and preventing water
pollution. The Archive, Downingtown. Pa., ¥ed. Nov. 18.
1970.
tfolny, P., 1967. Fertilization of warm water ponds in Europe.
W.P.P.C., (3)*64-8l.
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THE HARVESTING OF ALGAE AS A POOD SOURCE
PROM WASTEWATER USING NATURAL AND INDUCED
FLOCCULATION TECHNIQUES
by
Joseph L. Pavoni1, Steven W. Keiber2, and Gary T. Boblitt^
Conference on the
Use of Wastewater In the Production of
Pood and Fiber
Trade Winds Motor Inn - Central
Oklahoma City, Oklahoma
March 6-b, 1974
1. Associate Professor of Civil and Environmental Engi-
neering, University of Louisville, Louisville,
Kentucky 40205
2. Environmental Engineer, Hazelet and Erdal Consulting
Engineers, Louisville, Kentucky
3. Environmental Engineer, Kentucky Department of Trans-
portation, Frankfort, Kentucky 40601
435
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THE HARVESTING OF ALGAE AS A FOOD SOURCE
FROM WASTE WATER USING NATURAL AND INDUCED
FLOCCULATION TECHNIQUES
by
Joseph L. Pavoni1, Steven W. Keiber2, and Gary T. Boblitt3
INTRODUCTION
The autotrophic nature of algae has recently led to in-
creased speculation as to the usefulness of these micro-
organisms in various nutrient removal schemes applicable
to effluents from existing wastewater treatment plants.
Since algae characteristically utilize inorganic compounds
in the production of protoplasmic material, several ter-
tiary treatment processes have been developed which focus
upon' the "stripping" of basic nutrients from solutions via
normal algal metabolism. Whereas algae represent a con-
centrated mass of protein, fats, and carbohydrates, recent
interest has also been expanded to include algal cultiva-
tion for possible commercial food usages. Therefore, a
nutrient removal process which utilizes algae metabolism
for "stripping" purposes represents a means of processing
unwanted community wastes while economically, continuously,
and quickly providing a relatively pure potential food pro-
duct.
One of the serious drawbacks in any nutrient removal sys-
tem involving algae is the separation of these microorgan-
isms from the corresponding liquid phase. Regardless if
one is considering nuisance conditions in surface waters,
nutrient "stripping" processes, or the commercial produc-
tion of al^ae for food supplies, feasible methods of har-
vesting algae in all cases becomes of utmost importance.
1. Associate Professor of Civil and Environmental Engi-
neering, University of Louisville, Louisville,
Kentucky no20«
2. Environmental Engineer, hazelet and Erdal Consulting
Engineers, Louisville, Kentucky
3. Environmental Engineer, Kentucky Department of Trans-
portation, Frankfort, Kentucky 40bOi
436
-------
Among the various mass-liquid separation processes that
have been Investigated with regard to their potential for
algae 'Harvesting include: centrifugation, filtration,
flotation, ion-exchange, sedimentation, straining, chemi-
cal treatment, and biof locculation. V.lhile the majority of
these methods are quite costly, properly managed floccula-
tion techniques nay offer a feasible, as well as economi-
cal, solution to algal-liquid separation. The purpose of
tills investigation was therefore focused on describing
the feasibility of harvesting algae as a food source from
wastewater treatment systems using natural and induced
flocculation techniques.
LITERATURE REVIEW
Unlike bacterial aggregation, very little published re-
search information Is available pertaining to algal agglu-
tination. Initiating a discussion of algal flocculation
mechanisms necessitates an understanding of algal surface
charge.
Most algal cells (with the exception of certain filamentous
forms) fall in the size range of 5 to ^0 urn. Although
algae are larger than true colloids (1 to 100 nm), they
nevertheless possess many surface properties similar to
true colloids. Discrete algal cells are known to form sta-
ble microbial suspensions, possess a chemically reactive
cellular surface, and possess a net negative surface charge
(1) (2) due to the ionization of functional ionogenic
groups. Algae may be considered as hydrophilic bio-col-
loids since algal suspension stability depends not only on
the forces interacting between the particles themselves,
but also on the forces interacting between the particles
and. the water.
Algal_Bioflocculation Literature
Due to the limited amount of research conducted on algal
biofIccculation, documentation in the published, literature
of actual floe formation Is scarce. The agglutination of
5ii..El§Q2.l2.2:l1iriL stagnatile into settleable floes resembling
aerated activated sludge was observed by Eogan, Albertson,
et_ al (3) during a I960 investigation of phosphorus removal
by algae. It was postulated that the enclosure of the cell
by a broad gelatinous sheath (4), usually characteristic of
these filamentous algae, may have promoted entanglement of
filamentous algal appendages with consequent enhancement of
bioflocculation.
437
-------
A review of algal harvesting processes by Golueke and Os-
wald (5), in 1965, resulted in the attainment of biofloc-
culation under specific environmental conditions. The
necessary requirements were an actively photosynthesizing
shallow culture, a relatively warm day, and sunlight. How-
ever, as in the previous investigation, no hypothesis for
the algal bioflocculation mechanism was proposed.
In 1967, Schuessler (6) proposed an algal bioflocculation
model in which naturally produced polysaccharide polymers
would bridge between discrete algal cells. In his studies,
bioflocculation potential was correlated with the algal
growth phase - maximum algal removals being observed during
declining growth. Schuessler pointed out that declining
growth was a period of increased polysaccharide production
and excretion, thereby affording optimal bridging between
linearly extended polysaccharide polymers and algal cells
with resultant bioflocculation. Experimental results also
noted that high algal removals due to bioflocculation were
observed at both low and high ph levels. For the low pli
band from 1.0 to M.O, in which algae are in close proximity
to their isoelectric point, effective bioflocculation was
reported with best results at ph 3.0. For the high pH band
from ph 11,0 to 13.0, the algal removal efficiency was
greater than that observed in the low pK region and was
attributed to the formation of hydroxyl and carbonate pre-
cipitates that served to enmesh the algae with resulting
removal.
In 1969, Tenney, Echelberger, et_al_ (7) postulated a bio-
flocculation model In which high molecular weight exocellu-
lar metabolites, which are of sufficient length, bridge
between discrete algal cells, thereby initiating the bio-
flocculation process. They contended that the microbially
produced polymers initially might enhance floe formation,
while in later growth phases the accumulation of this ex-
tracellular material could be acting as a protective col-
loid.
While Investigating further the effects of algal exocellu-
lar polymer production on the bioflocculation process,
Pavoni (b) reported, in 1971, that algal cell aggregation
appeared to be governed by the physiological state of the
microorganisms. Observations indicated that floe formation
was restricted to the declining growth phase. In this
study, direct correlations were developed relating exocel-
lular polymer production and algal agglutination. Pavoni,
therefore, postulated surface coverage phenomenon as the
mechanism of algal bioflocculation, in which case surface
438
-------
potential reduction was not necessarily a prerequisite for
agglutination.
The excretion or exposure of natural polymers on the algal
surface during photosynthesis is widely documented in the
literature with the implication by several investigators
(9) (10) that the mechanism of algal bioflocculation is the
bridging function of naturally produced polymeric species.
It, therefore, seems appropriate to discuss the specific
types and quantities of these algal exocellular materials
referred to in the literature.
In 1849, Kutzing's original description of Navlcula pelli-
culosa (Synedra minutissima and pelliculosa)» according to
German (11), made reference to an algal gelatinous cap-
sule - "Individua in gelatina membranacea nidulantia" -
which has given the organism its present specific name.
In 1851, reports by Magin (12) indicated that through the
use of dyes Bailey found an external envelope of complex
carbohydrates to exist around the cell walls of diatoms.
Liebisch (13) showed these exocellular secretions to have
the same chemical nature as pectic compounds in 1929.
Various fresh and salt water algal species were observed
to secrete organic materials by Krough (14) and Aleev (15)
during the 1930's. In 1950, Locker (16) noted the presence
of slime on the surface of ponds containing an abundance of
Navicula pelliculosa. She noted the capsule of this spe-
cies, when cultured in the laboratory, sustained a posi-
tive carbohydrate stain.
Microscopic examinations of Anabaena, an algal species from
which Bishop, Adams, et al (1?) isolated an exocellular
polysaccharide, showed many of the filaments were enclosed
in a mucilaginous substance which was readily sloughed off
into the medium. This report of nitrogenous material se-
cretion by blue-green algae was supported in 1952 by Fogg
(18) who found polypeptide and amide secretion by young
cultures of Anabaena, a species of blue-green algae. That
same year Hough, Jones, et al (19) observed amylopectin-
like polymers in Qscillatoria while the species Nostoc
yielded a mucilaginous, complex, acidic polysaccharide
composed of a minimum of six distinguishable monosaccha-
rides.
In 1954, Bailey and Neish (20) found that polysaccharide
reserves, composed of amylose and amylopectin, constituted
up to 20 percent of the dry weight in some algal cultures.
439
-------
Secretions of peptides, amides, and amino-nitrosen were
observed by Fogg and Vfestlake (21) the next year, and their
report included emphatic remarks as to the importance of
such secretions to the ecology of fresh waters.
Lewis and Rakestraw (22) found carbohydrates in seawater in
quantities of from 0.1 to 0.4 mg/1 and attributed it to the
secretion products of planktonic algae. While Lev/in (23)
found no evident capsule around actively dividing Mavicula
pelliculosa cells, he did observe the formation of a gela-
tinous capsule, composed of glucuronic acid residues, fol-
lowing the cessation of cell reproduction.
Polysaccharide and organic acid secretion by green algae
was reported by Tolbert and Zill (24) and Allen (25) in
1956. Extending this specific research with unicellular
and colonial green algae, Lewin (26) observed that all
Chlamydomonas species studied liberated some soluble poly-
saccharides into the growth medium. This material was
found to constitute 25 percent of the total organic matter
produced by the cells of Chlamydomonas mexicana. In all
but one species, galactose and arabinose were the main
components of the polysaccharides. Lewin also postulated
other possible algal metabolites including free organic
acids and polypeptides.
Collier (27) demonstrated carbohydrate production in bac-
teria-free cultures of Prorocentrum, in 1958» while dis-
cussing the importance of naturally produced organic com-
pounds in surface waters. Krauss (2b) also reported find-
ing an exocellular polysaccharide material excreted by the
genus Oscillatoria. The same year Fogg and Boalch (29)
noted extracellular polysaccharide and nitrogenous con-
pounds in Ectocarpus confervoides and concluded that both
types of exocellular products are liberated from healthy
cells.
Carbohydrate accumulation, occurring initially during de-
clining growth and continuing into the endogenous growth
phase, was observed by Guillard and Wangersky (30). They
stated that cell demise liberated comparatively large
amounts of carbohydrate which could account for the pre-
sence of this material during the active growth phase.
Guillard and Wangersky, noting that algal photosynthetic
reserves amass during stationary growth under circumstances
unfavorable for the utilization of external carbohydrates
as an energy source, also postulated that these reserve
materials consist largely of other materials such as poly-
peptides and organic acids, which may also be present in
440
-------
the growth medium.
Mer?,, Zehnpfenning, et al (31) investigated species of
9l}^^y.Q™™&*L» Chlgrell.gV Chloracoccurn, and Scengdesmus, in
196*2, and noted some production of soluble exocellular
organic natter by the majority of autotrophic algal species
studies.
More recently, Moore and Tischer (32) reviewed the three
classes of organic compounds known to be liberated by
freshwater algae - organic acids, nitrogenous material such
as pclypeptides and free amino acids, and carbohydrate
polymers. Their investigation was specifically concentrat-
ed on the exocellular polysaccharide content of eight spe-
cies of green and blue-green algae. Results indicated
total polysaccharide production in amounts equal to 10 to
40 percent of the algal dry weight.
In summary, a large variety of organic substances have been
detected in the exocellular products of algae. These
materials can be classified into three general categories:
proteins, polysaccharides, and nucleic acids. With the
structure of most of these substances being polymeric and
with these materials possessing a net negative charge in
neutral Dh ranges, the exocellular products may be con-
sidered to respond as naturally produced anionic polyelec-
trolytes.
There is, however, a scarcity of information regarding the
role of these exocellular products in the algal agglutina-
tion mechanism. Consequently, any refinement of the algal
agglutination process would entail investigations into the
composition of the exocellular polymers, the mode of poly-
mer release from the cell, and the role of cell surface
potential.
Chemical Flocculation of Algae
The feasibility of removing algae from water and wastewater
by chemical flocculation techniques has -been studied by
several investigators. The available literature, although
limited, indicates the apparent feav^ibility of utilizing
this technique for algal removal. In 1958, Cohen, Rourke,
et_ ajl (33) conducted studies involving the agglomeration of
Chlorella cells with synthetic organic polyelectrolytes.
Results indicated that good flocculation was achieved while
using a cationic polyelectrolyte, whereas no flocculation
was observed with the anionic polymer.
447
-------
Golueke, Osvjald, et_ al_ (3*0 Indicated excellent aggregation
Chlorella and Scenedgsmus with cationic polyelectrolvtes
in 196*1. In these studies the requisite polyelectrolyte
dose was insensitive to pH in the range of 5.0 to 10.4;
however, increasing concentrations of dispersed algal cells
increased the requisite polyelectrolyte dose proportionate-
ly. Algal flocculation with anionic or nonionic oolyelec-
trolytes was not investigated.
More recently field scale pilot plant studies by the Dow
Chemical Company have served to demonstrate further the
feasibility of utilizing cationic polyelectrolytes as algal
flocculants.
In 1969, Tenney, Echelberger, et_ al_ (7) investigated the
feasibility of removing algae from water and wastewater
with synthetic organic polyelectrolytes. Representative
cationic, anionic, and nonionic synthetic organic poly-
electrolytes were used as flocculants. Under their experi-
mental conditions, chemically induced algal flocculation
occurred with the addition of cationic polyelectrolytes,
but not with anionic or nonionic polymers, although attach-
ment of all polyelectrolyte species to the algal surface
was shown. It should be noted, however, that anionic and
nonionic polymeric flocculation was only studied at pK 7.0.
Obviously, very little information Is available which be-
gins to delineate the parameters involved in the chemical
flocculation of algae using anionic or nonionic polyelec-
trolytes. It would appear that a basic need exists, not
only for the development of quantitative data regarding
the effectiveness of selected anionic and nonionic poly-
electrolytes as algal flocculants, but also for the evalua-
tion of the basic mechanism of algal-f locculation inter-
action and the associated parameters affecting this inter-
action. Also, since synthetic organic anionic and nonionic
polyelectrolytes most probably closely resemble natural
exocellular algal polymers, a correlation may exist between
synthetic polymer-algal interactions and natural polymer-
algal interactions.
EXPERIMENTAL PROCEDURE
The general experimental approach employed throughout this
investigation was to select scientifically established
techniques that would not only allow proper evaluation of
basic theoretical parameters, but also would be flexible
enough to thoroughly support reasonable variations in
experimental protocol. Analytical procedures chosen were
-------
sufficiently sensitive and specific for the scope of this
investigation but, nevertheless, were not overly sophisti-
cated to the point of being nonapplicable to the wastewater
treatment field.
Laboratory scale batch algal culturing reactors were used
throughout this investigation. The initial algal inoculum
was obtained from the inside wall of a secondary clarifier
at the Hite Creek Wastewater Treatment Plant in Louisville,
Kentucky. A typical algal culturing system consisted of a
40-liter glass Jar, a stone air diffuser which supplied
both aeration and complete mixing, a large cooling fan, and
a bank of flourescent lamps developed specifically to stim-
ulate photosynthesis. This light source imparted a culture
illumination of 400 foot-candles to the algal surface with
an energy dominance in the blue and red regions of the
visible light spectrum.
An initial algal concentration of approximately 10 to 20
mg/1 was inoculated into 25 liters of a standard liquid
algal medium (35), and daily pll adjustments were performed
when necessary to insure a pH between 7.0 and 7.5. All
evaporation losses were made up with distilled water .each
day previous to sample withdrawal. Culture temperature was
maintained at 22°C±2°C.
Once an algal batch reactor was begun, the experimental
procedure consisted of recording several parameters includ-
ing:
1. algal mass (dry weight basis) in accordance
with the procedures of Engelbrecht and Mc-
Kinney (36).
2. culture flocculation as a function of either
cake filtration time or percent transmission
at 520
3. algal cell surface charge using a Riddick
Zeta Meter (37).
4. extraction of exocellular polymer for quan-
titative monitoring (dry weight basis) and
fractional composition analysis.
Exocellular polymer extraction techniques utilizing ethanol
v/ere employed similar to the work of Ueda, et al (38).
Three samples secured from batch reactors were centrifuged
at 32,500 g for 15 minutes to affect shearing of polymeric
443
-------
material from the algal surface. The supernatent from
this centrifugation was added to 95 percent ethyl alcohol
so that the final ratio of volume was two parts ethanol to
one part supernatent. The supernatent-ethanol mixture was
refrigerated for 24 hours at 4°C after which time a white
fibrous precipitate was observed. Quantitative monitoring
of microbial polymer production was accomplished at this
point by performing a membrane filter suspended solids test
on two of the original three samples.
The white precipitate formed in the third sample was then
separated from the supernatent-ethanol liquid phase by
centrifuging at 32,500 g for 15 minutes and dissolved in
distilled water. This polymer solution underwent qualita-
tive colorimetric analysis for polysaccharide (39), pro-
tein (40), ribonucleic acid (RNA) (41), and deoxyribonu-
cleic acid (DNA) (42).
Plocculation of algal dispersions with synthetic organic
polyelectrolytes was performed utilizing standard jar
testing procedures (7). Algal suspensions were secured by
harvesting algae from batch cultures by means of centri-
fugation at 32,500 g for 15 minutes and resuspending the
algal pellet in a 0.5 percent aqueous sodium chloride
solution. This centrifugation procedure was repeated to
insure proper contaminant removal. Organic flocculants
used were produced by the Dow Chemical Company and included
cationic polyelectrolytes (C-31 and C-32), anionic poly-
electrolytes (A-22 and A-23), and nonionic polyelectrolytes
(N-ll, N-12, and N-17).
RESULTS AND DISCUSSION
Algal Bioflocculation Studies
Initially, laboratory batch fed algal cultures were nur-
tured to study the relationship between algal growth, cul-
ture turbidity, exocellular polymer production, exocellular
polymer to algal mass ratio, exocellular polymer composi-
tion, and cell surface charge. If current polymer bridging
models are to be expanded to explain algal biofiocculation,
then it should be possible to correlate algal culture
turbidity decrease with an increase in exocellular polymer
production. Additionally, algal cell surface charge would
be expected to remain constant throughout the entire growth
cycle.
The first study was comprised of a batch fed heterogenous
algal culture and was focused on duplicating and refining
-------
several correlations that had previously been shown to
exist for algal biof locculation phenomenon. A microscopic
analysis of this culture was performed to ascertain the
predominant al.ir.al species present in the medium. Chpjrella
and a filamentous strain were observed in abundant numbers;
however, a determination of which algal type predominated
and the exact identification of the filamentous strain were
not made.
he data frcn culture 1, as presented in Figures 1 and 2,
clearly demonstrate several significant aspects of biologi-
cal f locculation. Algal agglutination (culture turbidity
decrease) was observed to occur only after the algae had
entered endogenous growth stages (see Figures 1A and IB).
The dependence of the algal biof locculation process on the
physiological state of the algae agrees with previous
investigations by Favoni (8) and parallels results obtained
for similar bacterial systems (43). Filtration time
(sec Figure 1C) was also observed to be a qualitative mea-
sure of algal biof locculation in agreement with the work of
La-'or and liealy (i\>\}. The filtration time in this culture
was observed to reach a maximum prior to endogenous growth
and decrease steadily from that point as biof locculation
phenomenon increased.
If current polymer bridging models are to be expanded to
explain algal biof locculation, it should be possible to
correlate algal culture turbidity decrease with an increase
in exocellular polymer production. As indicated in Figure
2A, the algal exocellular polymer concentration in culture
1 increased significantly during endogenous growth (a peri-
od of enhanced agglutination). The inference, as in bac-
terial systems, is that this exocellular polymer is the
primary cause of biof locculation during endogenous growth.
Since the ratio of exocellular polymer to algal mass sharp-
ly increases during culture aggregation (see Figure 2B),
the polymer bridging model of biof locculation is further
supported. Correspondingly, the increase in this ratio
indicated that surface coverage phenomenon may have been
responsible for increased agglutination.
Another important aspect of the biof locculation process is
the mode of polymer release from the algal cell. Algal
aggregation was noted as being limited to endogenous growth
with a concurrent increase in exocellular polymer concen-
tration during the growth phase. Since restricted growth
is a period of massive cell lysis, algal autolysis may have
been the mechanism of polymer release.
Whereas culture 1 was investigated solely for the purpose
445
-------
I
CQ
01
m
I
Ul
11
c
nj o
£H ift
4J
C I
<1>
O C
Vi O
(U -H
CU tQ
O
(1)
w
I
0)
••-I
•P
(0
M
4J
•H
•H
150
100
50
40
50
100
25
20
15
10
-
A. Algal Mass
B. Culture Turbidity
C. Filtration Time
• •»• —
1
1 1
1 1
10
15
20
25
Days of Growth
Figure 1
Culture 1 Data Depicting (A) Algal
Growth, (B) Culture Turbidity, and
Filtration Time.
(C)
446
-------
c
o
•H
+J
-p e
c
CD i
u
o "CQ
U -H
W
M fd
CU PQ
0 Q
OJ
0)
O
0
X
w
100
75
50
25
0
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
A. Exocellular Polymer Concen-
tration
B. Exocellular Polyme^ to Algal
Mass Ratio
0
Figure 2
10
15
20
25
Days of Growth
Culture 1 Data Depicting (A) Exocellular
Polymer Production and (B) the Ratio of
Exocellular Polymer to Algal Mass.
447
-------
of refining the characteristics of previously observed
phenomena, culture 2 was developed and monitored to deter-
mine the algal cell surface charge through the entire
growth cycle and the fractional composition of extracted
exocellular polymer. Knowledge of cell surface charge
and exocellular polymer compositional makeup could signifi-
cantly shed light on the understanding of the overall 'bio-
flocculation process.
A-microscopic analysis of culture 2 revealed the presence
of a dense population of Chlorella with only occasional
sightings of filamentous strains. Therefore, Chlorella
were determined as being the predominant species in this
culture.
The results of culture 2 relevant to the refinement of pre-
viously observed bioflocculation phenomenon paralleled
those of culture 1, i.e., a correlation was observed be-
tween the endogenous growth phase and enhanced aggregation
(see Figures 3A and 3B). Filtration time was again ob-
served to serve as a qualitative indicator of biofloccula-
tion phenomenon (see Figure 4A).
If polymer bridging theories are to be expanded to explain
algal bioflocculation, cell aggregation should be indepen-
dent of surface potential reduction. The algal cell zeta
potential was monitored in order to evaluate the algal sur-
face charge during the complete growth cycle of culture 2.
Figure 4B shows that no significant changes in zeta poten-
tial were observed during any algal growth phase. The sta-
bility of the cell surface charge indicated that surface
potential reduction was not a prerequisite in the biofloc-
culation mechanism. Since a bioflocculation model based on
some measure of charge neutralization would involve the
formation of tightly compacted cell aggregates, the inde-
pendence of surface charge and algal bioflocculation ob-
served in this investigation added support to the polymer
bridging theory in which discrete cells are loosely bound
in a three-dimensional matrix.
Algal exocellular polymer produced in culture 2 was also
extracted and weighed to develop polymer/algal mass ratios.
Unlike results observed in culture 1, the polymer concen-
tration in culture 2 remained virtually constant throughout
all growth phases with only a minor increase detectable
during endogenous growth (see Figure 5A). Although the
exocellular polymer to algal mass ratio increased during
endogenous growth, this increase appeared incremental when
compared to that obtained in culture 1 (see Figure 5B).
-------
A. Algal Mass
I
CO
co
tn
C
O
•H
W
CO
•H
6
W
C
to
4J
C
(U
O
M
0)
500 _
400
300
200 -
100 h
0
4
8
10
20
40
10
B. Culture
Turbidit-*
20 30 40
Days of Growth
50
Figure 3
Culture 2 Data Depicting (A) Algal Growth
and (B) Culture Turbidity.
449
-------
A. Filtration Time
o
0)
CO
-------
250
o
•H
-P
A. Exocellular Polymer
Concentration
VH tP
0) I
o
r* ^-"H.
o w
CJ -H
CO
200
150
100
Oi
50
rH
O
cu
OJ
to
to
I
(C
Cn
o
o
B. Exocellular Polymer to Algal
Mass Ratio
10
Figure 5
20
30
40
Days of Growth
50
Culture 2 Data Depicting (A) Exocellular
Polymer Production and (B) the Ratio of
Exocellular Polymer to Algal Mass (from
Weight Analysis).
457
-------
It is believed, however, that the extracted polymer in
culture 2 was contaminated with inorganic material.
Friedman, et al ('45), while isolating exocellular polymer
from Zoogloea ramigera, observed the presence of inter-
fering materials in the polymeric precipitate.
Consequently, another polymer production curve was devel-
oped for culture 2 by adding the concentrations of the
individual components (polysaccharide, protein, RNA, DNA)
found in the fractional composition tests. This curve,
presented in Figure 6A, shows a more significant increase
in exocellular polymer concentration during endogenous
growth, and the ratio of exocellular polymer to algal mass
also shows a marked increase during late growth (see Figure
6B).
In comparing the polymer production curves obtained from
weighing the polymer and from the fractional composition
analysis (refer to Figures 5A and 6A), a substantial dif-
ference in polymer values can be observed. This difference
was postulated as arising from the precipitation of inor-
ganic constituents which increased the polymer totals in
the weighing procedure, but had no effect on the specific
compositional analysis techniques. To determine whether or
not inorganic Interference was occurring, several observa-
tions were made of precipitated polymer. Following filtra-
tion of a polymer sample, examination of the membrane fil-
ter indicated the presence of not only long strain polymer-
ic fibers, but also fine, granular particles. Consequent-
ly, a membrane filter containing the filtered precipitate
was combusted in a muffle furnace at 600°C. Since the fil-
ter itself left no ash, the residue remaining represented
inorganic contaminants present in the sample. It is impor-
tant to note that a significant amount of residue was ob-
served after combustion. Therefore, it can be assumed that
inorganic precipitates were formed during the ethanol ex-
traction in agreement with Friedman, et_ al_ (45).
Of major importance in a description of the algal biofloc-
culatlon process, as developed from the polymer bridging
model, is the composition of the exocellular polymer. Sam-
ples of the polymer-ethanol mixture were centrifuged to
separate the polymer from the liquid phase. The exocellu-
lar polymer was then added to 20 ml of distilled water and
fractional composition analysis techniques were performed.
The analysis was designed to categorize the polymeric com-
ponents into the broad classifications of protein, RNA,
DNA, and polysaccharide. Figures 7A, 8A, 9A, and 10A
represent the concentrations of the major components of
452
-------
O
-H
4->
(0
^
4J
G
OJ
u
c
O
u
(U
e
O
0)
e
o
en
S
•H
ti
0)
u
o
X
w
50
40
30
20
10
0
0.4
0.3
A. Exocellular Polymer
Concentration
0.2
0.1
B. Exocellular Polymer to Algal
Mass Ratio
10
20
30
40
50
Days of Growth
Figure 6 Culture 2 Data Depicting (A) Exocellular
Polymer Production and (B) the Ratio of
Exocellular Polymer to Algal Mass (from
Fractional Composition Analysis).
453
-------
ff
c
o
•H
-p
-p
c
Q)
u
c
O
U
C
•H
o
4J
O
M
(X
25
A. Protein Content in
Exocellular Polymer
•H
-------
o
•H
4J
c
-------
c
o
•H
-P
cti
M
-P
C
Q)
O
c
o
u
Q
5
4
A. DNA Content in Exocellular
Polymer
B. DNA to Algal Mass Ratio
to
to
m
0
Figure 9
Days of Growth
Culture 2 Data Depicting (A) the DNA
Fraction of Exocellular Polymer and (B)
the Ratio of DNA to Algal Mass.
456
-------
e
i
c
o
•H
•P
M
-P
0)
U
c
o
T3
•H
U
O
(0
to
><
rH
O
0)
8
6
4
0.04
0.03
O.t)2
0.01
A. Polysaccharide Content in
Exocellular Polymer
B. Polysaccharide to Algal Mass Ratio
* 1
) 10
v —^r-— — -
1 1
20 30
1
40
•
1
50
Figure 10
Days of Growth
Culture 2 Data Depicting (A) the Poly-
saccharide Fraction of Exocellular Polymer
and (B) the Ratio of Polysaccharide to
Algal Mass.
457
-------
exocellular polymer observed throughout the algal growth
curve. These data show the total concentration of each
component to increase during endogenous growth and the
ratio of each component to algal mass to also increase
during this growth phase (see Figures 7B, BE, 9B, and 10E).
Consequently, it appeared that all major components of the
exocellular polymer were involved in the increase in poly-
mer production associated with algal bioflocculation; how-
ever, it should be noted that protein and RNA appeared most
prevalent in the compositional makeup of the exocellular
polymer from this culture.
To substantiate bioflocculation phenomena observed in cul-
ture 2, a third culture consisting of Chlorella as the
predominant algal type was investigated. Data from culture
3 (see Figures 11 through 16) closely paralleled that
developed for culture 2. Inorganic contamination of ex-
tracted exocellular polymer was again observed.
The conclusions of the algal bioflocculation studies may be
summarized as follows:
Algal agglutination appeared to be governed by the physio-
logical state of the microorganisms. Algal flocculation
was not observed to occur until the microbes had entered
into a state of restricted growth (endogenous growth
phase).
A direct correlation was found to exist between exocellular
polymer production and microbial aggregation. Since exo-
cellular polymer to algal mass ratios dramatically in-
creased during algal flocculation, surface coverage pheno-
menon may be interpreted as the mechanism by which bio-
logical flocculation occurs.
Cell surface charge investigations indicated that surface
potential reduction is not a necessary precursor to algal
bioflocculation.
The major compositional makeup of exocellular algal consti-
tuents associated with bioflocculation may be classified
into four general categories of organic polymers: poly-
saccharides, proteins, RNA, and DNA, thereby implying nega-
tive polymer charge characteristics.
The mechanism of algal bioflocculation is interpreted as
resulting from the interaction of high molecular weight
exocellular polymers, which have sufficiently accumulated
at the microbial surface during endogenous growth. These
458
-------
Cn
e
CO
ra
S
c
o
•H
CO
W
C
ta CD
-p -P
-------
9
C
o
•H
•P
c
o
u
M
0)
O
(X
p<
tn
to
I
id
o>
o
o
X
35
30
25
20
15
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Exocellular Polymer
Concentrat ion
*
I
B. Exocellular Polymer to Algal
Mass Ratio
10
15
20
25
Days of Growth
Figure 12 Culture 3 Data Depicting (A) Exocellular
Polymer Production and (B) the Ratio of
Exocellular Polymer to Algal Mass (from
Fractional Composition Analysis).
460
-------
tr>
I
Q)
-p
o
c
•H
Q>
-P
O
J-f
04
to
03
(C
S
•H
(0
Cr>
<:
20
18
16
14
12
10
8
0.4
0.3
0.2
0.1
A. Protein Content in Exocel-
lular Polymer
I
I
B. Protein to Algal Mass Ratio
I
10 15 20
Days of Growth
25
Figure 13 Culture 3 Data Depicting (A) the Protein
Fraction of Exocellular Polymer and (B)
the Ratio of Protein to Algal Mass.
461
-------
I
flj
H
<
15
10
5
0.2
0.1
A.
RNA Content in Exocellular
Polymer
1
J_
1
B. RNA to Algal Mass Ratio
10 15
Days of Growth
20
25
Figure 14 Culture 3 Data Depicting (A) the RNA
Fraction of Exocellular Polymer and
(B) the Ratio of RNA to Algal Mass.
462
-------
z
Q
10
W
(0
CP
4 I-
3
2
0.05
0.04
0.03
0.02
0.01
A. DNA Content in Exocellular
Polymer
I
B. DNA to Algal Mass Ratio
Days of Growth
Figure 15 Culture 3 Data Depicting (A) the DNA
Fraction of Exocellular Polymer and
(B) the Ratio of DNA to Algal Mass.
463
-------
tr>
e
i
0)
•H
0
0
i-H
O
o«
o
JG
O
O
fOl
CO
10
to
(0
m
tn
>iH
rH
O
fU
3
2
0.1
0.08
0.06
0.04
0.02
0
0
A. Polysaccharide Content in
Exocellular Polymer
B. Polysaccharide to Algal
Mass Ratio
10 15
Days of Growth
20
25
Figure 16 Culture 3 Data Depicting (A) the
Polysaccharide Fraction of Exocellular
Polymer and (B) the Ratio of Poly-
saccharide to Algal Mass.
464
-------
polymers electrostatically or physically bond, ana nubsc-
auently bridge, the cells of the dispersion into a three-
dimensional matrix of sufficient magnitude to subside under
quiescent conditions. Surface potential reduction is not
necessarily a prerequisite for agglutination in this model.
Algal flocculation can most conveniently be viewed in terms
of surface coverage relationships.
Chemical_Flqcculation Studies
Batch algal reactors were utilized in this study to supply
algal suspensions for chemical flocculation testing that
would be similar to algal samples found in typical waste-
water treatment systems. The function of the batch reactor
was to simulate the growth of an incremental volume of
mixed algae as it passed through an oxidation pond. The
particular algal growth phase was not a ma.lor consideration
in this study but rather the algal concentration at any
specific time. Most chemical flocculation experiments uti-
lized algal suspensions directly from the batch reactors
with no pre-treatment to simulate as closely as possible
flocculation phenomena that might be observed at an opera-
tional oxidation pond.
The composition of a "typical" algal culture utilized dur-
ing the chemical flocculation investigation Is given in
Table 1.
Table 1. Typical Composition of
Mixed Algal Cultures Utilized
During Chemical Flocculation Studies
Broad Group
Green Unicellular
Algae or Small
Group (2-4 cells)
Blue-green
Filamentous
Green Filamentous
Diatoms
Green Colonial
Genera
Chlorella
Euglena
Scenedesmus
Oscillatoria
Ulothrix
Fragilarla
Synedra
Volvox
Number
of Species
2
1
2
3
2
1
1
Percent
ELomass
40
29
29
1
465
-------
Effect of Hydrogen Ion Concentration on Algal Autof loccula-
tion - Before attempting to determine the feasibility of
flocculating algal suspensions with synthetic organic poly-
electrolytes, it was necessary to determine the effect of
hydrogen ion concentration on algal autof locculation. This
data would then serve as a reference while conducting opti-
mum pH and dosage studies for each polymer. Consequently,
an algal suspension at a concentration of 166 mg/1 was
flocculated at varying pH levels (from 1.0 to 11. U) with no
polymer addition. The resulting data, as shown in Figure
17, depicts maximum algal autoflocculation phenomena occur-
ring at a pH of 3.0. This study indicates that natural
flocculation is maximized when the surface charge of the
algal biocolloid is minimized, i.e., near the isoelectric
point or point of zero charge (8). At the algae's isoelec-
tric point (pH 3.0) the electrostatic repulsive forces will
be reduced to a minimum, thereby allowing the biocolloids
to assume interparticle distances sufficient for van der
Waal's forces to promote optimum flocculation.
Alga^Fl occ ulation with Synthetic Organic Poly electro-
lytes - The polymer flocculation of algal study was intend-
ed to investigate the effectiveness of various cationic,
anionJc, and nonionic synthetic organic polyelectrolytes
on the aggregation of various algal suspensions. The ex-
tended segment theory of polymer flocculation would predict
that to achieve optimal flocculation for a given algal sus-
pension, an optimal concentration of poly electrolyte must
be added at an optimal pK level. Addition of polyelectro-
lyte at pH levels other than optimum or at concentrations
greater or less than the optimum will not achieve the maxi-
mum degree of flocculation. The pE will affect the surface
charge density of the biocolloid and various polymer physi-
cal characteristics including linear extension, degree of
ionization, and charge density. Polymer dose will control
biocclloid surface coverage.
Consequently, the initial study focused on the effect of pH
on the cationic polymer flocculation of algae. Standard
Jar tests were performed in the study at a constant cation-
ic polymer (C-32) dosage of 2 mg/1, a constant algal con-
centration of 161 mg/1, and pK values varying from 1.0 to
11.0. Results indicated that optimum flocculation appeared
at pH 3.0 (see Figure 18). This appears reasonable since
the algal biocolloid exhibits a net charge of approximately
zero at this pH level and, therefore, interparticle separa-
tion distances are at a minimum. Additionally, the cation-
ic polymer possesses a high positive charge at this pH
level and is, therefore, well extended. Similar phenomenon
466
-------
50
O
£
o
OS
-P
c
CD
o
S-i
Q)
40
30
20
10
Algal Content =166 mg/1
1
'
I _ I _ I - 1 - 1 - 1 - L
123456789 10 11 12
PH
Figure 17 Relationship Between Algal Bioflocculation
and Varying pH Values.
467
-------
ITS
>
(0
-p
c
0)
o
>-l
0)
p<
100
90
80
70
60
50
40
30
20
10
Algal Content = 161 mg/1
Dosage of C-32 =2.0 mg/1
I I I
I I
12345 67 8 9 10 11 12
PH
Figure 18 Algal Plocculation with Cationic Polymer
C-32 at Varying pH Values.
468
-------
were observed with another cationic polymer, C-31.
To determine the optimum cationic polymer dosage for algal
flocculation, a study was conducted at the optimum pH
(3.0), a constant algal concentration (166 mg/1), and vary-
ing dosages of C-32 (from 0 to 20 mg/1). The results, as'
shown in Figure 19, illustrate that optimal flocculation
occurs with a C-32 dose of 1.0 to 5.0 mg/1. These data
correspond to the current polymer bridging theoretical
framework that states that flocculation is enhanced by
polymer addition up to a certain dosage (approximately 50
percent surface coverage of the algal cell), and that addi-
tion of polyelectrolyte beyond that dosage results in re-
stabilization of the algal biocolloid.
Anionic polymers were the next group of polymers studied.
Again, standard jar testing procedures were utilized to
determine the optimum pH level for anionic flocculation of
algae utilizing a constant A-23 dosage of 5 mg/1, a con-
stant algal concentration of 166 mg/1, and varying pH lev-
els from 1.0 to 11.0. Results indicated an optimum pK of
3.0, similar to that obtained with cationic polymer sys-
tems (see Figure 20). However, whereas the mechanism of
cationic polymer attachment was apparently electrostatic
(due to opposite algal-polymer charges), the anionic poly-
mer is thought to attach by chemical means, i.e., hydrogen
bonding or anion interchange. It again appears reasonable
that optimal flocculation phenomena occur at pll 3.0 (the
algal isoelectric point) since this is the point at which
the biocolloids possess a minimum separation distance.
Similar pH phenomenon was observed with another anionic
polyelectrolyte, A-22.
To determine the optimum anionic polymer dosage for algal
flocculation, a study was conducted at the optimum pH of
3.0, a constant algal concentration of 166 mg/1, and vary-
ing A-23 dosages from 0 to 20 mg/1. The results, illus-
trated in Figure 21, indicate an optimum dosage of 1 to 2
mg/1 A-23. Algal flocculation at the optimum A-23 dosage
was only slightly improved over a system with no polymer
(about 10 to 15 percent). This poor increase in floccula-
tion efficiency appears to be due to the fact that the neg-
ative polymer is of insufficient length to bridge between
the algal cells (i.e., to overcome the electrostatic
repulsive separation distance and attach itself to the
colloidal surface). Optimum algal flocculation most pro-
bably occurs at pH 3.0 because at this point the net nega-
tive surface charges on both the algal cell and polymer are *
sufficiently reduced to allow some bridging to occur. It
469
-------
90
>
0)
0)
o
M
0)
04
80 _
70 -
60
50
40
Algal Content = 166 mg/1
pH = 3.0
6 8 10 12 14
Dosage of C-32 (mg/1)
16 18
20
Figure 19 Algal Flocculation at Optimum pH (3.0)
with Varying Dosages of Cationic Polymer
C-32.
470
-------
OJ
1
QJ
(0
•P
C
-------
fC
i
0)
Oi
1C
-P
c
a)
o
V4
a)
Pu
70 «
Algal Content = 166 mg/1
pH = 3.0
60 _
50
40
6 8 10 12 14
Dosage of A-23 (mg/1)
16
18
20
Figure 21 Algal Flocculation at Optimum pH (3.0)
with Varying Dosages of Anionic Polymer
A-23.
472
-------
should be noted that similar flocculation phenomena were
observed with another anionic polymer, A-22.
Optimum pH and polymer dosage studies were also performed
with nonionic polymers, i.e., polymers having a net charge
of zero. To determine the optimum pH for algal floccula-
tion with a nonionic polymer, N-12, a standard jar test was
performed at a constant algal concentration of 153 nig/1, a
constant N-12 dosage of 2.0 rag/1, and varying pH values
from 1.0 to 11.0. The results of this study again indicat-
ed an optimum pH of 3.0 (see Figure 22). The poor floccu-
lation achieved with the nonionic polymers can again be
attributed to insufficient polymer chain length. Optimum
flocculation again occurs at the point where the electro-
static repulsion forces are minimum and, therefore, al-
low some polymer bridging to occur. At the elevated pH
ranges the repulsive forces produce biocolloid separation
distances large enough to prevent polymer adsorption onto
the surface of the algal cell.
To determine the optimum dose of N-12 for algal floccula-
tion, a study was conducted at the optimum pH (3.0), a
constant algal concentration of 171 mg/1, and a polymer
dosage varying from 0 to 20 mg/1. The results, shown in
Figure 23, indicate an optimum dosage of 5.0 mg/1. This
nonionic polymer at its optimum dosage achieved an in-
crease in algal removal over that achieved by the anionic
polymers. However, it was again postulated that the non-
ionic polymers were of insufficient length to bridge the
electrostatic separation distance effectively. Although
the biocolloid-nonionic polymer repulsion forces are as-
sumed to be minimal due to the net nonionic polymer charge
of zero, the surface charges of both the polymer and algal
cell still appear to exert a significant effect upon algal
flocculation with nonionic polymers. It should be noted
that similar flocculation data was developed with two
other nonionic polymers, N-ll and N-17.
In summary, Figure 24 illustrates the general effect of pH
upon algal flocculation with various polymers. With each
polymer tested the flocculation phenomenon followed the
same general pattern. The major factor controlling these
results appears to be the isoelectric point (i.e., point
of zero charge) of the algae which occurs at a low pH lev-
el and dominates polymer flocculation mechanisms. The
effect of optimum polymer dosage followed a pattern in
that dosages beyond the optimum resulted in decreased al-
gal removal. This effect appears to arise from biocolloid
restabilization due to excessive surface coverage with
47J
-------
flj
>
0)
100
90
80
70
60
& 50
40
<
-P
0)
o
n
£ 30
20
10
Algal Content = 153 mg/1
Dosage of N-12 =2.0 mg/1
I I I I I
12 34 5 67 89 10 11 12
PH
Figure 22 Algal Flocculation with Nonionic Polymer
N-12 at Varying pH Values.
474
-------
(0
>
o
e
QJ
OS
tr>
H
<
4J
C
O
Q)
0<
70 _
60
50
Algal Content = 171 mg/1
pH = 3.0
40
1 j
2 4
1
6
1
8
1
10
1
12
1
14
1
16
1
18 2
Dosage of N-12 (mg/1)
Figure 23 Algal Flocculation at Optimum pH (3.0)
with Varying Dosages of Nonionic Polymer
N-12.
475
-------
It)
i
s
(0
rH
<
C
Q)
O
H
0)
100
90
80
70
60
50
40
30
20
10
0
• Algal Bioflocculation
A Dosage of C-31 = 15 mg/1
• Dosage of A-23 = 5 mg/1
V Dosage of N-17 = 2 mg/1
10 11 12
pH
Figure 24 Effect of Varying pH Values on Algal
Flocculation Synthetic Polymers.
476
-------
polymer.
Algal Flocculation at Naturally Occurring pH Levels - Since
the majority of naturally occurring biological systems
operate in the neutral pH ranges, it was decided to con-
duct some polymer flocculation tests at pH 7«0« The ini-
tial study conducted at pH 7.0 was to determine the effi-
ciency of algal flocculation with cationic polymers C-31
and C-32. Results indicated optimum C-31 and C-32 polymer
dosages of 15 rog/1 and 20 mg/1, respectively (see Figure
25). The significant difference between these tests and
the ones previously conducted at the optimum pH of 3.0 is
that the dosages required for optimal algal flocculation
are considerably increased. This is probably due to in-
creased biocolloidal electrostatic repulsive forces since
the algal biocolloid becomes more negative as the hydro-
gen ion concentration decreases. Also, the cationic poly-
mer will be less extended at higher pH values.
Algal flocculation studies were also performed with certain
anionic and nonionic polymers at pH 7.0 to determine the
effect of neutral pH levels on algal removal with these
polymers. The results of these studies, as shown in Figure
26, indicate that very little polymer bridging is occurring
probably due to insufficient polymer length. Also, the
electrostatic repulsive forces are significantly increased
on the algal surface at pH 7.0 compared to pH 3.0. These
factors plus the inability of anionic and nonionic polymers
to perform a charge neutralization function result in poor
algal removal.
Algal_ Flocculation wl_th__Pqlvmer_s and Trivalent Metal Ion
Additives - The remainder of this investigation concen-
trated on algal removal with anionic polyelectrolytes, in
particular Dow Purifloc A-23. Since in the previous stud-
ies flocculation was not achieved with polymer addition
alone, it was decided to add a trivalent metal ion to act
as a bridge between the negative algal particle and the
negative polymer. It was felt that the trivalent metal ion
could achieve one or both of the following functions.
First, the metal ion could reduce the algal cell surface
potential, thereby allowing the negative polymer to over-
come the electrostatic separation distance and attach it-
self to the algal surface, thereby allowing bridging be-
tween the various cells. Or secondly, it was felt that the
metal ion could serve as a bridge between the algal cell
and anionic polymer forming a biocolloidal-metal ion-poly-
mer-metal ion-biocolloid complex. If either or both mecha-
nisms were achieved, good settling was expected to result.
477
-------
Dosage of Cationic Polymer (mg/1)
Figure 25 Algal Flocculation with Cationic Polymers
C-31 and C-32 at pH 7.0.
478
-------
to
s
g
<1>
PS
rH
(C
C
0)
U
H
0)
CM
30
20
10
0
10
Algal Content = 400 mg/1
pH = 7.0
lAnionic Polymer A-22
iAnionic Polymer A-23
Nonionic Polymer N-12
i I ' I L
20 30
Dosage (mg/1)
40
50
Figure 26 Algal Flocculation with Anionic and
Nonionic Polymers at pH 7.0.
479
-------
Alum (aluminum sulfate) was chosen as a representative
netal ion because of its wide use in the field of water and
wastewater treatment. The initial study utilizing alum
involved the addition of varying alum concentrations (from
0 to 100 mg/1 as Al^"1") to algal samples at a constant pH of
7.0 and a constant algal concentration of 170 mg/1. The
results indicated an optimum dose in the range of 15 to 20
mg/1 as depicted in Figure 27. Algal flocculation was
achieved primarily by charge neutralization with the posi-
tive aluminum metal ion. If the positive metal ion is add-
ed in excess of the optimum dosages, it can cause restabi-
lization of the colloidal suspension. This occurs by ad-
sorption of the positive metal ion into the diffuse layer
around the algal cell in such quantities that the net
charge on the particle becomes positive, thus causing
electrostatic repulsion. The optimum dosage of the metal
ion occurs when adsorption of the positive ion has re-
duced the surface potential to its lowest point, thereby
allowing van der Waal's forces to dominate and cause floc-
culation.
To determine algal removal phenomena with A-23 and alum, a
study was conducted at the optimum alum dosage (20 mg/1), a
constant pH (7.0), a constant algal concentration of 176
mg/1, and a varying A-23 dosage (from 0 to 20 mg/1). The
results, depicted in Figure 28, illustrate an optimum A-23
dose of 1.0 mg/1. The removal of algae was considerably
improved over a similar system without the alum addition
(see Figure 26). This would indicate that the metal ion is
capable of serving as a bridge between the negative algal
colloid and the negative polymer. Also, the alum-polymer
system improved flocculation over that of alum alone (see
Figure 26).
The second trivalent metal ion utilized was Fe3+ in the
form of ferric chloride. An initial study was performed
to determine the optimum iron dosage. This test was con-
ducted on algal samples at a constant concentration of
166 mg/1, a constant pH of 7.0, and an iron dosage varying
from 0 to 100 mg/1 as Fe^ . The results, as shown in
Figure 29, indicate an optimum iron dosage of 50 mg/1.
Iron dosages above 50 mg/1 caused restabilization of the
biocolloids and thus hindered the flocculation process.
This phenomenon is similar to that observed with the alumi-
num.
To determine the optimal A-23 dose for algal removal with
an iron additive, a study was conducted as a constant pH
of 7.0, a constant algal concentration of 170 mg/1, a con-
480
-------
50
i
0)
ITS
r-<
<
-P
CD
o
i-l
40
30
20
10
0
Algal Content = 170 rag/1
pH = 7.0
«.
I
_L
I
I
20 40 60 80
Dosage of Alum as A13+ (mg/1)
100
Figure 27 Algal Flocculation with Varying Dosages
of Alum at pH 7.0.
481
-------
80
«t
4J
c
Q)
O
H
-------
(C
I
-------
stant Fe3+ dosage of 50 mg/1, and varying dosages of A-23
ranging from 0 to 20 mg/1. The results, depicted in
Figure 30, show that over 90 percent algal removal is
achieved with an A-23 dose of 1.0 mg/1. Although the algae
was effectively removed with the addition of the Fe^4" and
A-23, the mechanism of removal did not appear to be solely
that of polymer bridging. Due to an excess of phosphate
ion in the culture medium, it appeared that the Fe^* was
precipitating the phosphate causing an enmeshment of al-
gae and polymer in the iron-phosphate precipitate. Re-
stabilization of the biocolloidal system did not seem ap-
parent from the results but would probably occur at exces-
sively high polymer dosages. Even though these results de-
pict effective algal removal, such removals would not be
achieveable in actual systems since naturally occurring al-
gal systems usually contain about no more than 4 mg/1 to
5 mg/1 of phosphorus, whereas the culture media contained
several hundred mg/1 of phosphorus. Therefore, the next
series of studies were performed to determine whether or
not these high removals could be achieved in a harvested
algal culture.
The first investigation conducted on a harvested culture
(i.e., a culture with a phosphate content less than 1.0
mg/1) was to determine the optimum iron dosage. A study
was conducted at a constant pH (7.0), a constant algal
concentration (166 mg/1), and varying dosages of Fe^*
(ranging from 0 to 500 mg/1). The results, shown in Figure
31, indicate an optimum iron dosage of 200 mg/1. The algal
removal curve again shows a peak with decreased removals
occurring when iron is in excess of the optimum. However,
the significant factor is that the optimum iron dosage is
considerably higher ('J times as great) in the harvested
suspension as opposed to the "dirty" suspension. This
would seem to indicate that algal enmeshment in the iron-
phosphorus precipitate did occur in the previous study.
Also, the percent algal removal achieved by the iron at
the optimum dose was reduced by about 50 percent as corn-
pared to the removals achieved in the "dirty" suspension
(nee Figure 29).
T
he next investigation was intended to determine the per-
cent algal removal with A-23 and iron in the harvested
culture. A study was performed at a constant algal con-
centration (166 mg/1), a constant pK (7.0), the optimum
iron dosage (200 mg/1 as Fe^ ), and varying dosages of
A-23 varying; from 0 to 20 mg/1. The results depict an op-
timum A-23 dosage occurring at 0.5 mg/1 with subsequent
reduction in percent removals due to excessive A-23 doses
-------
100
90
nj
O
e
CD
PS
Algal Content = 170 mg/1
Iron as Fe3"1" = 50 mg/1
pH = 7.0
80 .
c
-------
It)
i
0)
OS
Cn
-P
c
0)
o
M
0)
(X
Algal Content = 166 mg/1
pH = 7.0
100 200 300 400
Dosage of Iron as Fe3+ (mg/1)
500
Figure 31 Algal Flocculation in a Harvested Culture
with Varying Dosages of Iron at pH 7.0.
486
-------
causing restabilization of the algal biocolloids (see
Figure 32). These removals are markedly reduced from
those illustrated in Figure 30. These data again support
the theory that algal enmeshment in the iron-phosphorus
complex was occurring. Although enmeshinent of the algal
cell in the phosphate precipitate appeared to be the major
removal mechanism, some bridging probably occurred between
algal cells as well as between the iron-phosphate precipi-
tate and the algal cells.
However, flocculation did occur in the harvested culture
indicating that the anionic polymer-ion bridge was capable
of removing algae in suspension. The mechanism of algal
flocculation appeared to be a combination of charge-neutra-
lization and bridging or a combination coagulation-floccu-
lation phenomenon.
Two final studies were performed to determine the effect
of iron addition on algal flocculation with cationic and
nonionlc polymers. The initial jar test was conducted at
a constant algal concentration of 170 mg/1, a constant ph
of 7.0, a constant iron dosage of 50 mg/1 as Fe^*, and
varying dosages of C-31 ranging from 0 to 15 mg/1. The
results of this study, as shown in Figure 33, indicate an
optimum C-31 dosage of 1.0 mg/1 as compared to approxi-
mately 15 rng/1 previously reported in Figure 25 for a
similar system without iron additive. Apparently, the
iron-phosphate complex is enmeshing the algae to such an
extent that the polymer dosage required for destabilization
of the algal suspensions is greatly reduced. However, the
addition of the cationic polymer significantly enhances al-
gal removal beyond that achieved with iron additives alone
due to its ability to electrostatically attach to the algal
biocolloid, thereby forming polymer bridges.
The last study conducted was intended to determine the
effect of the optimum iron dosage on algal removal with a
nonionic polymer. This Jar test was conducted at a con-
stant algal concentration of 168 mg/1, a constant pH of
7.0, a constant Fe-^ dosage of 50 mg/1, and varying dosages
of N-ll from 0 to 20 mg/1. The results, shown in Figure
3^, illustrate an optimum polymer dosage occurring at 0.5
mg/1. Algal removals observed were vastly improved over
those obtained in algal suspensions flocculated with N-12
alone (see Figure 26). It is postulated that this im-
proved algal removal is due to algal enmeshment in an
iron-phosphate precipitate. However, the M-12 was ob-
served to Improve algal removal beyond that obtained
H87
-------
(0
I
Q)
OS
tn
-u
c
0)
o
70
Algal Content = 166 mg/1
Iron as Fe = 200 mg/1
60
50
40
30
20
I
I
I
I
I
6 8 10 12 14
Dosage of A-23 (mg/1)
16 18
20
Figure 32
Algal Flocculation with the Optimum Iron
Dosage (200 mg/1) in a Harvested Culture
and Varying Dosages of Anionic Polymer
A-23 at pH 7.0.
488
-------
100
Algal Content = 170 mg/1
Iron as Fe3+ = 50 mg/1
pH = 7.0
90
o
e
0)
en
rH
<
-P
0)
o
(1)
80
70
60
50
Figure 33
Dosage of C-31 (mg/1)
Algal Flocculation with the Optimum Iron
Dosage (50 mg/1) and Varying Dosages of
Cationic Polymer C-31 at pH 7.0.
489
-------
(0
g
E
0)
(C
0>
.H
4J
C
0)
o
H
-------
with iron addition only.
In summary, the mechanism of algal removal using nonionic
arid cationic polymers appears to be enneshment. in the
phosphate precipitate being formed as a result of iron
addition. Algal removals observed in cationic polymer-
iron systems were considerably greater than those in non-
ionic polyrner-irori systems since the cationic polymer
electrostatically bridged, between the algal cells, whereas
the nonionic polymer had to rely on adsorption phenomenon
for attachment to the biocolioid surface.
The conclusions of the chemical fiocculation studies may be
summarized as follows:
The optimum pH for algal agglutination with synthetic
organic polyelectrolytes appeared to be in the range of pH
2.0 to 4.0, thereby implying that polymer fiocculation
mechanisms are governed by the algal cell surface charge.
Optimum dosages of all synthetic polymers at optimum pFi
levels appeared to be in the range of 0.5 to 5.0 mg/1 with
subsequent restabilization of the algal suspension at
higher polymer dosages.
At neutral pH levels the cationic polyelectrolytes utilized
appeared to effectively flocculate the algal suspension
through a combination of polymer bridging and charge neu-
tralization, whereas anionjc and nonionic polyelectrolytes
failed to efficiently flocculate the algae at pK 7.0 due to
their inability to bridge the repulsive separation distance
and chemically bond to the cell surface.
The addition of trivalent metal ions to algal suspensions
flocculated with polyelectrolytes was observed to signifi-
cantly enhance algal fiocculation phenomena compared to
algal' removals obtained with either trivalent metal ion or
polymer addition only. It is postulated that the trivalent
metal ion enhances fiocculation phenomena by reducing the
algal cell surface charge (reducing biocolioid separation
distances) and possibly serving as a bridge between the
algal cell surface and the polyelectrolyte.
CONCLUSIONS
It appears that algae utilized in nutrient removal schemes
for wastewater treatment may provide a potential food pro-
duct if they can be efficiently harvested. Natural and
induced fiocculation techniques apparently may promote
497
-------
efficient algae-liquid separation at reasonable costs.
The results of this investigation imply that algae har-
vesting by means of bioflocculation or chemically in-
duced flocculation techniques can be accomplished in a
very efficient manner under certain conditions. It, there-
fore, seems imperative that further research be focused on
algal bioflocculation and chemically induced flocculation
mechanisms on a pilot scale to develop pragmatic opera-
tional data which could be utilized to accomplish effective
algal harvesting as a food source.
AC KNO WLEDGEMENT
This investigation was supported by a National Science
Foundation Engineering Research Initiation Grant GK-32732
awarded to Joseph L. Pavoni.
The kindness of the Dow Chemical Company for supplying
samples of synthetic organic polyelectrolytes is appreci-
ated.
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nical Association of the Pulp and Paper Industry, 47,
No. 1 (January 1964).
38. Ueda, S., Fujita, K., Komatsu, K., and Nakashma, Z.,
"Polysaccharide Produced by the Genus Pullularia, I.
Production of Polysaccharide by Growing Cells," Ap-
plied Microbiology, 11^ 211 (1963).
39. Dubois, M., Gilles, K. A., Hamilton, J. K., Rebers,
P. A., and Smith, F., "Colorimetric Method for Deter-
mination of Sugars and Related Substances," Analytical
Chemistry. 28, 350 (1956).
40. Lowry, 0. H., Rosebrough, N. J., Farr, A. L., and
Randall, R. J., "Protein Measurement with the Folin
Phenol Reagent," Journal Biological Chemistry. 193»
265 (1951).
495
-------
41. Morse, M. L., and Carter, C. E., "The Synthesis of
Nucleic Acids in Cultures of Escherichia coli, Strains
B and B/R," Journal Bacteriology, 33, 317 (19^9).
42. Burton, K., "A Study of the Conditions and Mechanism
of the Diphenylamine Reaction for the Colorimetric
Estimation of Deoxyribonucleic Acid," Journal Bio-
chemistry, 62_, 315 (1956).
43. Pavoni, J. L., Tenney, M. W., and Echelberger, W. P.
Jr., "Bacterial Exocellular Polymers and Biological
Flocculation," Journal Water Pollution Control Federa-
tion, 44_, 414 (March 1973).
44. LaMer, V. K., and Healy, T. W., "Adsorption-Floccula-
tion Reactions of Macromolecules at the Solid-Liquid
Interface," Reviews of Pure and Applied Chemistry,
13., 112 U9637:
45. Friedman, B. A., Dugan, P. R., Pfister, R. M., and
Remsen, C. C., "Fine Structure and Composition of the
Zoogloeal Matrix Surrounding Zopgloea ramigera,"
Journal of Bacteriology. 96, 2144 (1968).
-------
CRITICAL VARIABLES IN FOOD-ITEM
POPULATION DYNAMICS IN A WASTE-WATER AQUACULTURE SYSTEM
by
Joseph E. Powers*
INTRODUCTION
Increases in human populations and the associated increases in domestic
wastes have made it essential that beneficial methods of disposal of
these wastes be developed. One suggestion was the addition of treated
sewage to aquaculture ponds (Allen*). Nutrient-rich sewage waters
added to an ecosystem would generally increase the primary production
and lead to higher productivity in the system as a whole. But, in
order for such a strategy to be effective in an aquaculture system, it
is mandatory that the majority of the energy that results directly from
the sewage addition be channelled into the species being cultured and
not lost to other populations within the system. This implies that
simple straight-chain food-webs would be most effective in aquaculture.
Therefore, in managing aquaculture systems, it is imperative that there
be an understanding of the key variables associated with the population
dynamics of the major food organisms.
An aquaculture system fertilized by domestic sewage was constructed
adjacent to Humboldt Bay, California (Allen, Conversano and Colwell2)
for use in rearing salmon (Oncorhynchus kisutch) to the smolt age,
i.e., the age at which they migrate to the ocean. Ultimately such a
system will provide a return run of,adult salmon to Humboldt Bay.**
The primary food organism which developed within this pond was the
gammarid amphipod Anisogammarus confervicolus Stimson. Powers^ re-
ported on the structure and general results of a simulation model des-
cribing the dynamics of this amphipod population. That simulation
model is now used to give evidence as to the nature of the critical
variables affecting the dynamics of the amphipod population. This
evidence is formulated into a possible management strategy and some
generalizations concerning management of these types of aquaculture
systems are made.
*Department of Fisheries and Wildlife Sciences, Virginia Polytechnic
Institute and State University, Blacksburg, Virginia.
**The ponds were constructed by the Conservation Board of the
California Department of Fish and Game and are operated under
National Sea Grant Funds, California State University, Humboldt
Coherent Area Project, Northern California Coast.
497
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THE AQUACULTURE SYSTEM
The Humboldt Bay aquaculture system consists of a 1.4 hectare pond lo-
cated within the perimeter of a 55-acre oxidation pond. Tertiary-
treated domestic sewage could be introduced from the oxidation pond to
be mixed with sea water from Humboldt Bay.
Major animal populations existing in the pond (other than the salmon
and amphipods) were two species of fish: sticklebacks (Gasterosteus
aculeatus) and topsmelt (Atherinops affinis). These fish entered as
larval or egg forms through a metal screening device which strained
the inlet water from Humboldt Bay. Holes in the device were six milli-
meters in diameter. These apertures were the means by which the amphi-
pods gained access to the pond, as well.
THE SIMULATION MODEL
The model consists of a system of difference equations that are updated
each of 22 time periods. Each period corresponds to three days of
actual time. The amphipod population was divided into age classes and
at each time period the vital statistics of ration size, growth, preda-
tion by fish populations and natural mortality, i.e., mortality other
than predation (assumed to be the result of the direct effect of temp-
erature and salinity) were computed for each age class. Inputs into
the model consisted of initial population estimates for the fishes and
amphipods, temperature and salinity measurements, predation rates of
fish on the amphipods, amphipod reproduction rates and particulate
organic matter (POM) measurements, all of which were taken directly
from studies of the aquaculture pond (POM measurement method was that
of Lovegrove^).
The initial simulation used these inputs exactly as they were measured
in the pond. Subsequent runs were made with perturbations of most of
the inputs in order to discern the key relationships.
RESULTS
Most of the amphipods that entered the pond through the Humboldt Bay
inlet were adult forms (Figure 1) and, therefore of too large a size
to be utilized by the small fingerling salmon. In order to maintain a
stable food-item population in the system, the population must be
allowed the time to develop. The importance of this lag time and its
approximate length can be observed in Figure 2. This figure actually
displays two lag times: 1) the lag between conversion of the sewage
nutrients to POM, and 2) the subsequent conversion of POM to amphipod
biomass. The pond was filled with sewage water and sea water seven
days before the initial time used in the simulation. Approximately
30 days lag time was needed for POM build-up and 45 days for amphipod
build-up.
498
-------
GO
c
CO
CO
CO
0)
C
(U
o
(-1
CD
O
00
18
36
54
Time in Days
Figure 1. Changes in Amphipod Size Distribution with
Time.
POM
CN
60
g
o „
CO
. , . , . Amphipods
12
~T"
24
—T
36
• Cv|
CM I
O
00
a
o -H
CO
C
V
Q
n
CO
48
60
Time in Days
Figure 2. Particulate Organic Matter and Simulated
Amphipod Biotnass Density versus Time.
499
-------
Table 1. Effects of Salinity on Amphipod Growth Rate
Salinity (ppt)
Average Growth
Rate (mg dry/day)
Age
(days)
3
6
9
12
20
Ave Weight
(mg dry)
0.376
0.468
0.581
0.718
0.038
24
Ave Weight
(mg dry)
0.377
0.471
0.587
0.728
0.039
16
Ave Weight
(mg dry)
0.373
0.462
0.569
0.697
0.036
Table 2. Effects of Density on Amphipod Growth Rate
Amphipods/m^
Age
(days)
3
6
9
12
15
188.27
Ave Weight
(mg dry)
0.376
0.469
0.583
0.722
0.889
782.23
Ave Weight
(mg dry)
0.311
0.384
0.476
0.588
0.721
Average Growth
Rate (mg dry/day) 0.043 0.034
500
-------
X
CO
60
W
•O
O
ex
E
o
•
o
18
—i—
54
27 36 45
Time in Days
Figure 3. Simulated Egg Production versus Time
63
507
-------
A decrease in the lag time would be a desirable goal in an aquaculture
system. This could be attained by starting with an amphipod population
composed primarily of young animals and/or by having an increased
growth rate of the amphipods. Manipulations of several of the system
variables could produce such changes in growth rate.
Salinity changes caused flux in the growth. Results from computer runs
at three different salinities on day 24 of the simulation are shown in
Table 1. The average growth rate of 15-day-old smphipods appeared to
be greatest at a salinity of 24 parts per thousand (ppt). Similarly,
the effects of population density on day 45 of the simulation are
shown in Table 2. Quadrupling the amphipod density resulted in a 26.4
percent decrease in the growth rate over the first 12 days of life.
Another cause for this lag in biomass production is the reproductive
process (Figure 3). Total reproduction did not rise appreciably until
day 36. This rapid increase was caused by growth into reproductive age
of the amphipods which, themselves, were produced in the pond. It was
at this stage that the size distribution of the pond began to stabilize.
DISCUSSION
A major concern in managing an aquaculture system is that of establish-
ing an adequate food source for the species being cultured. In the
Humboldt Bay salmon culture project, it appears that this can be
achieved most effectively by maintining a brood stock of amphipods and
by controlling the salinity.
Maintenance of a brood stock would mean assuring the survival of a
sufficient number of amphipods from one culture session to the next,
i.e., the pond should not be completely drained allowing some habitat
in which the amphipods could reside. Also, the pond should be refilled
as soon as possible after the partial draining to further minimize
mortality.
Salinity manipulations could be used to maximize amphipod growth rate.
If the initial salinity was kept at 24 ppt, the amphipods would grow
fast and quickly establish the population. This salinity (24 ppt) was
shown to be optimum from the laboratory studies using in fitting data
to equations in the simulation model5. Then salinity could be lowered
(the proportion of freshwater could be increased) to meet the physiolo-
gical needs of the salmon. Temperature would affect growth rate as
well, but it is unlikely that temperature control would be economi-
cally feasible.
A large number of sticklebacks and topsmelt entered the aquaculture
system and grew to a size that was capable of exploiting the amphipods.
This introduced the element of interspecific competition to the salmon.
502
-------
This aspect should be eliminated from the system. Since the incoming
water cannot be screened any more finely (or else the amphipods could
not enter) the time of the year the ponds are filled should not coin-
cide with the times in which large numbers of eggs and larval fish
appear in Humboldt Bay.
CONCLUSION
Sewage water can bring added productivity to an aquaculture system, and
by judicious management that productivity can be shunted into the
desired species. The food-item must be allowed to develop a sufficient
population. The time needed for this development can be decreased by
controlling system variables at the optimal levels for the food-item.
Once the food-item population is somewhat stable and able to with-
stand environmental pressure, the system variables should be converted
to levels optimal for the species being cultured. Species which do not
contribute directly to the cultured species should be eliminated from
the system entirely.
REFERENCES
1 Allen, G. H. The Constructive Use of Sewage, with Particular Ref-
erence to Fish Culture, FAO Technical Conference on Marine Pollu-
tion and its Effects on Living Resources and Fishing. Paper No.
Fir: Mp/70R-13, 1970.
2 Allen, G. H. , G. Conversano and B. Colwell. A Pilot Fish-pond
System for Utilization of Sewage Effluents, Humboldt Bay, California
Marine Advisory Extension Service, Sea Grant Program, California
State University, Humboldt, CSUH-SG-3, 1-25, 1972.
3 Powers, J. E. The Dynamics in a Salmon Culture Pond. Simulation.
21(4): 69-72, October 1973.
4 Lovegrove, T. The Effects of Various Factors on Dry Weight Valves.
J. H. Faser, ed. Contributions to Symposium on Zooplankton Produc-
tivity, Rapports et Proces-Verbaux Des Reunions, 153: 86-91, 1961.
5 Powers, J. E. Ibid.
503
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THE FEASIBILITY OF PENAEID SHRIMP CULTURE IN BRACKISH PONDS
RECEIVING TREATED SEWAGE EFFLUENT*
William L. Rickards**
INTRODUCTION
The study described herein was one part of an extensive investigation
of the ecological structure and functioning of brackish water pond
systems receiving treated sewage effluent. The studies were con-
ducted at the University of North Carolina Institute of Marine Sciences
in Morehead City, N. C. from 1969 through 1972. Details concerning
the results of the four-year program were presented by Odum and
Chestnut,1Kuenzler and Chestnut,3*3 and Kuenzler, Chestnut and Weiss*
in project annual reports.
Experimental facilities for the program consisted of six 0.1 acre
ponds, three of which received brackish tidal creek water plus
treated sewage effluent while the remaining three ponds received
only brackish water and served as control units.
The long-range goals of the overall sewage study program included
the development of methods of aquaculture which would utilize the
effluent of sewage treatment plants as well as providing a screening
device for organisms with the ability to withstand the environmental
fluctuations which occur in ponds receiving the effluent.
During the two previous years of the pond project, penaeid shrimp
had been stocked in both the control ponds and the sewage ponds.
The results of these stocking attempts were described by Beeston5>6.
In both cases, the shrimp survived and grew in the control ("C")
ponds but failed to survive in the sewage ("P") ponds. At the
time, it was the opinion of project personnel that failure of the
shrimp to survive in the "P" ponds was due to the very low levels
of dissolved oxygen in the water at night (Smith7) as well as rather
wide diurnal pH fluctuations (Laughinghouse and Kuenzler6).
Despite the failure of penaeid shrimp to survive, aquacultural interest
in them because of their economic value prompted the study described
below. The objectives of this study were to modify the oxygen and pH
regimes in one of the "P" ponds and to subsequently stock the pond
with penaeid shrimp to determine whether or not factors in addition
to oxygen and/or pH had been responsible for the previous shrimp
mortalities.
*This study was sponsored by Office of Sea Grant, NOAA, U.S. Dept.
of Commerce under Grant No. 2-35178, and the State of North Carolina,
Department of Administration.
**University of North Carolina Sea Grant Program, 1235 Burlington
Laboratories, North Carolina State University, Raleigh, N. C. 27607
504
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I. HABITAT IMPROVEMENT STUDY
In an attempt to alter the "P" pond habitat so that penaeid shrimp
would be able to survive, P-2 was selected for a study in which the
pond was aerated. It was hoped that a relatively small amount of
aeration would alleviate the extremely low dissolved oxygen encountered
in the early morning hours by other investigators (Smith7). Since
penaeid shrimp generally require dissolved oxygen levels of at least
2.0 ppm, 3.0 ppm was considered a desirable level to attempt to
maintain in P-2.
METHODS
Prior to aeration, pond maintenance procedures involved routine daily
measurement of dissolved oxygen, temperature, and pH in the evening
and early morning. In addition, a diurnal dissolved oxygen curve
was determined on 20-21 June, 1971. On 14 July 1971, aeration of
the pond was begun by means of a 3/4 horsepower, oil-less compressor
and 200 feet of perforated plastic air hose. The hose was arranged
in a four-leaf clover pattern so that all areas of the pond received
aeration. During the period 14-22 July, dissolved oxygen, pH, and
temperature fluctuations were monitored. Temperature and pH were
measured by recording instrumentation at the pond. Dissolved oxygen
was determined by Winkler titration of samples fixed at the pond
and returned to the laboratory.
RESULTS AND DISCUSSION
Prior to aeration, the dissolved oxygen varied diurnally from 0.0
mg/1 to about 13.5 mg/1 as shown in Figure 1. Values plotted in
Figure 1 are averages of triplicate measurements taken at different
depths and locations in the pond.
Following aeration, fluctuations in the diurnal curve had moderated
(Figure 1). Neither the daytime peak nor the early morning low
point reached those experienced without the aeration. Of greatest
interest was the maintenance of an average minimum dissolved oxygen
value of 3.4 mg/1 over the seven day period of measurement.
In addition, the pH which had at times varied from 7.5 to nearly
10.0 on a diurnal basis was now being maintained within a much
narrower range, 7.6 to 8.3 Water temperatures did not differ
noticeably between the two periods being compared.
Use of the compressor and perforated air line did not stir up the
bottom sediments. This could have been a problem since increased
turbidity' in the system would have resulted in lower rates of photo-
synthesis by the phytoplankton possibly pushing the system past the
point of compensation where production balances respiration. This
would not be desirable since phytoplankton production is the basis
505
-------
16
14
10
» 8
E
5 6
0
>•
X
o
2 2
, NO AltATtON - JO-JI JUNI
. WITH AltATION • 15-31 JUIT
o
o
TIME
Figure 1. The average dissolved oxygen in milligrams per liter
on a diurnal basis for Pond P-2 before and during
aeration.
506
-------
for the food chains being investigated as sources of aquacultural
products in systems receiving treated sewage effluent.
CONCLUSIONS
Aeration of pond P-2 by the means employed maintained dissolved
oxygen well above 3.0 mg/1 which had been accepted as the minimum
desirable level.
Aeration had no detectable effect on temperature, but diurnal
fluctuations in pH were moderated as had been desired at the beginning
of the study period.
As a result of the modification of the pond environment into one
which was more favorable for penaeid shrimp, it was decided to
undertake studies to determine whether or not shrimp could now
survive and grow in the "P" ponds.
II. SHRIMP SURVIVAL
The objective of this aspect of the study was to determine whether
or not penaeid shrimp could survive in the modified environment of
pond P-2. If survivors were found, growth would then be measured.
METHODS
On 20 August 1971, juvenile white shrimp (Penaeus setiferus) were
seined from Hoop Hole Creek, a tidal slough on the sound side of
Bogue Banks near Atlantic Beach, N. C. The shrimp were transported
to the laboratory and transferred to a holding pen through which
water from Bogue Sound circulated. The shrimp were held overnight
and were released into ponds C-2 and P-2 the next morning. Thus,
on 21 August, C-2 received 221 juveniles and P-2 received 211
juveniles.
Additional juvenile P. setiferus were added to the same ponds on
13 September bringing the total numbers of shrimp to 321 in C-2
and 287 in P-2. No attempt was made to stock the ponds to carrying
capacity. A sample of 35 of the juveniles were preserved in 10%
formalin for weight and length determinations.
On 10 November seine hauls were made in each pond stocked. Sampling
recovered 60 shrimp from C-2 and 33 shrimp from P-2. Weight and
length were determined for each shrimp.
Because shrimp were released into the ponds on two occasions, 21
August and 13 September, those shrimp recovered on 10 November were
in the ponds for either 82 or 59 days. Data discussed in the
following sections are based on an average stocking data of 1
September giving an average duration in the ponds of 70 days.
507
-------
RESULTS AND DISCUSSION
Figure 2 shows the average initial and final weights of the shrimp
recovered from P-2 and C-2. Whereas shrimp in both ponds were
stocked at the same average weight (1.4 grams) those in P-2 grew to
a slightly greater average weight (14.8 grams) than did those in
C-2 (13.45 grams). Average shrimp lengths were also somewhat larger
for shrimp from P-2 than for those from C-2 (Table 1), 121.5 mm
as compared to 113.3 mm.
The increase in weight of shrimp in P-2 was 13.4 grams in approximately
70 days or 0.97 mm in length per day. Such growth compares favorably
to that of shrimp in natural populations in North Carolina (McCoys
McCoy and Brownio Williams**). Thus, it would appear that the "P"
pond environment may be made suitable for growing penaeid shrimp
simply by aeration of the water.
Differences in the numbers of shrimp recovered from P-2 and C-2
may have been due to several reasons. However, the most likely
reason would be the difference in bottom type between the two ponds.
C-2 has a fairly firm bottom in which seining is much easier than
in P-2 which has a very soft, muddy bottom into vhich the shrimp
can burrow and which makes seining very difficult.
In addition, mortality of the stocked shrimp may have been greater
in P-2 than in C-2. This could not be verified since it was impossible
to recover all of the shrimp in either of the ponds. The presence of
numerous blue crabs in P-2 could have resulted in greater losses of
shrimp in that pond than in C-2 in which fewer blue crabs were seen.
Also shown in Figure 2 are the changes in heads-on count (number of
shrimp per pound) which occurred during the study. When stocked,
the juveniles were approximately 300 count heads-on, and they were
approximately 30 count in P-2 and 50 count in C-2 on 10 November.
Shrimp of 30 count weight are well within a marketable size range.
Thus, shrimp of coranercial size were produced in the pond receiving
treated sewage effluent.
Supplementary feeding was not employed during the study, and it is
assumed that the shrimp were feeding on the numerous small organisms
and accumulated detritus in the ponds.
CONCLUSIONS
Penaeid shrimp were able to survive and grow in the aerated "P" pond.
It is now logical to proceed with studies of penaeid shrimp food
chains utilizing treated domestic effluent and production dynamics
in aquacultural applications.
505
-------
16
15
14
13
12
II
10
O)
X
O
flL
irt
ui
O
< 4
at
UI
< 3
2
1 -
15 25
AUG.
C2
P2
14 24
SEPT.
14 24
OCT.
I,
30
80
130
Q
Z
3
O
D.
180
230 O
Z
O
I
in
280 Q
325
3 13
NOV.
Figure 2. Changes in the average weight and heads-on count
(number of shrimp per pound) during the study period
for shrimp stocked in ponds P-2 and C-2.
509
-------
Table I. Data obtained from shrimp stocked in ponds P-2 and C-2.
Shrimp lengths were measured from the tip of the telson
to the base of the rostrum. Data ranges are in parentheses,
SHRIMP IN POND P-2 SHRIMP IN POND C-2
Number stocked 287 321
Average No. days 70 70
in pond (59-82) (59-82)
Average initial weight 1.40 1.40
(grams) (0.4-3.1) (0.4-3.1)
Average initial length 57 57
(mm) (36-75) (36-75)
Number sampled 33 60
10 Nov.
Average final weight 14.77 13.45
(grams) (5.0-21.0) (4.0-21.0)
Average final length 122 113
(mm) (92-139) (84-130)
510
-------
Shrimp growth in the "P" ponds approximated that found in natural
populations of penaeid shrimp in North Carolina. Thus, there
appeared to be no detrimental effects on growth resulting from the
extremely eutrophic environment employed.
It appears that such eutrophic environments may be benefically
employed as grow-out ponds in shrimp culture operations since shrimp
of marketable size were produced. In addition, it may be possible
to obtain three crops from such grow-out facilities in North Carolina
depending on the duration of favorable water temperatures in a
particular year.
Literature Cited
1. Odum, H.T. and A.F. Chestnut. 1970. Studies of marine estuarine
ecosystems developing with treated sewage wastes. Univ. of
North Carolina. Sea Grant Project Ann. Kept. 1969-1970.364 pp.
2. Kuenzler, E.J. and A.F. Chestnut. 1971a. Structure and functioning
of estuarine ecosystems exposed to treated sewage wastes.
Univ. of North Carolina. Sea Grant Project Ann. Rept.
1970-1971. 345 pp.
3. Kuenzler, E.J. and A.F. Chestnut. 1971b. Structure and functioning
of estuarine ecosystems exposed to treated sewage wastes.II.
Univ. of North Carolina. Sea Grant Project Ann. Rept.
Supplement. 1970-1971. 50 pp.
4. Kuenzler, E.J., A.F. Chestnut, and C.M. Weiss, 1973. Structure
and functioning of estuarine ecosystems exposed to treated
sewage wastes, III, 1971-1972. Univ. of North Carolina,
Sea Grant Pub. UNC-SG-73-10. 222 pp.
5. Bees ton, M.D. 1970. Crustaceans and fishes in the Sea Grant
ponds. In Odum, H.T. and A. F. Chestnut, 1970. pp. 272-279.
6. Bees ton, M.D. 1971. Decapod crustaceans and fish populations in
experimental ponds receiving treated sewage wastes, in
Kuenzler E.J. and A.F.Chestnut, 1971a. pp. 182-204.
7 Smith M 1971. Productivity of marine ponds receiving treated
sewage, in Kuenzler, E.J. and A. F. Chestnut, 1971a. pp. 24-41.
8 Laughinghouse, W.R. and E.J. Kuenzler. 1971. Insolation, pH, and
turbidity, in Kuenzler, E.J. and A.F. Chestnut, 1971b.
pp. 3-8.
577
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9. McCoy, E.G. 1968. Migration, growth, and mortality of North
Carolina pink and brown penaeid shrimps . N.C. Dept. of
Conserv.and Devel., Div. of Comm. and Sports Fisheries.
Spec. Sci. Rept. (15):1-26.
10. McCoy. E.G. and J.T. Brown. 1967. Migration and growth of
commercial penaeid shrimps in North Carolina. N.C. Dept.
of Conserv. and Devel., Div. of Comm. and Sports Fisheries,
Spec. Sci. Rept. (ll):l-29.
11. Williams, A.B. 1955 A contribution to the life histories of
commercial shrimps (Penaeidae) in North Carolina. Bull
Mar. Sci. Gulf and Caribbean, 5_:116-146.
572
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STANDING CROPS OF BENTHIC FAUNA IN MARINE AQUACULTURE
PONDS USING RECLAIMED WATER
by
Thomas R. Sharp*
INTRODUCTION
In a time of worldwide shortages of food and energy, it is
essential that new methods of human food production be
developed. One possible method is to produce fish for
human consumption from domestic wastewater (Allen1). An
important link between wastewater nutrients and fish pro-
duction is the benthic fauna, a basic food for most fish
(Darnell2). The placing into operation of two experimen-
tal aquaculture ponds in July 1971 located within the
confines of a city wastewater treatment plant next to the
tidal flats of North Humboldt Bay (Allen and Dennis3 ,
Fig. 1) provided the opportunity for studying the effects
of treated domestic wastewater on estuarine benthic fauna.
The primary purpose of this study was to determine the
differences in benthic standing crops between the
fertilized pond and the unfertilized pondy North Pond
was managed as a static estuarine-sewage effluent mixture.
The South Pond was an estuarine pond only, and was tidally
flushed every 2-3 weeks (Allen and Dennis3, Figures 1-3).
To determine a desirable substrate for fish food produc-
tion in future aquaculture ponds, the benthic standing
crops on four available substrates were studied; substrates
included mud, sand(Hookton soil), river-run gravel, and
oyster shell. Pens to exclude fish were used to determine
the effect fish predation had on benthic standing crops.
Since this study began with the initial filling of the
ponds, the colonization of the ponds was studied for
comparisons with conditioned pond bottoms in future
experiments.
METHODS AND MATERIALS
Temporal Changes in Benthos
In order to study fluctuations in benthic animal nutrients
over time, a transect technique was employed. A transect
*Department of Fisheries, Humboldt State University,
Arcata, California.
**TT-i-io -investiaation was supported by funds from the
Humboldtnstitegu5lv¥rsity Coherent Area Sea Grant Program.
573
-------
line was marked by a rope stretched between the headgate
and the northeast corner of each pond. This line was
located over areas of mud substrate only (Sharp1*) . Monthly,
beginning September 1971, five core samples were taken at
6 meter intervals along the transect line of each pond.
Ten samples were taken on each sampling date for a total
of 50 samples over the course of the study. The time of
the study corresponds to Pond Experiment IB (Allen and
Dennis3, Table 2). Thus the early stages of succession
were not covered.
Benthos was sampled using a Carrin core sampler (Carrin5)
having a diameter of 4 inches (surface area of about 80 cm2)
Each sample was washed through a 0.457 mm Tyler screen and
the part remaining preserved in 10% formalin solution. The
organisms were sorted to species and counted. The speci-
mens of a species in a sample were dried at 100°C for 24
hours (Hanks6) and weighed on an analytic balance.
Standing Crop
In order to study the standing crop of benthos at the end
of the rearing experiment, an "in-place" sampling technique
was used. An in-place basket sampler similar to that
o f Hanks6, with modifications to accommodate the dif-
ferent substrates and changes in water level was employed
(Figure 1). The sampler consisted of a 2-quart polyethelyne
basket with a surface area of 200 cm2 and a volume of 1600
cc. Triangular cut-outs covered by 0.457 mm Nitex nylon
were made into the sides of each sampler to allow for water
circulation which might occur in the substrates, especially
in shell. A brick and float were attached by two lengths of
nylon twine. The brick prevented the float twine from
interfering with the substrate surface.
"Exclusion pens" enclosing an area of 4 m2 were built on
each of four substrates within each pond (Sharp1*) . On
July 13, 1971 the in-place basket samplers were installed
as follows. At each station (substrate within a pond) six
samplers were filled with the appropriate substrate and
placed so that the surface of the sampler was flush with
the surface of the pond bottom. Three of the samplers
were put inside the exclusion pen and three outside the
pen (Sharp1*). Thus, with four substrates in each pond,
and two ponds, a total of 48 samples were installed
(Figure 2).
The ponds were initially filled July 21, 1971 and finally
drained on January 15 and 22, 1972. The samplers were
withdrawn from North Pond December 13, 1971 and from South
574
-------
STAINLESS
STEEL WIRE
FIBERGLASS
RESIN
Figure 1. In-place Basket Sampler used for .Substrate
study (top surface area, 200 cm2; volume
1600 cc).
575
-------
Oi
SUBSTRATE STUDY
Figure 2. Flow diagram of the substrate study.
-------
Pond December 20, 1971, before either pond was drained.
Benthos and sediments in the basket samplers were processed
in the same manner as that used for the transect samples
with the following exceptions:
1. Mud, sand, and gravel samples underwent a sugar
floatation technique (Anderson7) to eliminate the large
volumes of substrate remaining after seiving.
2. Due to the high numbers of organisms in North Pond,
all North Pond samples were divided in half using a Folsom
Plankton Splitter and the results doubled.
3. For weighing, the three replicate samples on each
test area were pooled and the results averaged.
METHODS OF ANALYSIS
A three-way analysis of variance (Sokal and Rohlf8) was
employed to analyze the number of benthic animals only
taken in basket samplers. The analysis was to test which
treatment (pond, substrate, or exclusion pen)was signifi-
cant for each of the major species found in the study. A
standard logarithmic transformation (100 log [X+l] where
X is the number of animals in each sample) was used to
make the data more homogenous. Calculated F values for
each treatment were compared with tabulated F values for
a significant level of p=.05. If the F value was larger
than the tabulated value, the treatment was considered
significant.
A Student-Newman-Kreuls Test for multiple comparisons among
means based on equal sample size (Sokal and Rohlf ) was
used to determine significant factors within treatments.
If the treatment being considered was substrate, the
factors considered would be mud, sand, gravel and shell.
Numbers/M2 and biomass(dry weight/M2) were calculated from
both transect samples and in-place basket samples. Wet
weights/M2 were calculated from dry weight data using
conversion formulae (Thorsen9). Total numbers/M and wet
weights/M2 were calculated for ponds, substrates and
exclusion pens, using in-place basket sample data and for
each sampling period using transect sample data. The
basket sample totals were compared with other studies.
RESULTS
Organisms Present
The organisms found in the ponds included two species of
polychaete,
-------
Polydora ciliata Fabricus (Spionidae) ; and two species of
gammarid amphipod, Anisogammerus conferviaolus Stimpson, and
Corophium spinicorne Stimpson (Table 1) . Daphnia spp shells
were found in large numbers but were considered artifacts
from the oxidation pond. Bryozoans were not quantified.
Great numbers of dipteran insect pupae casts were found
but not considered part of the benthos. Other species
occurred but in low numbers.
Changes in Standing Crops with Time
Both polychaete populations increased to November or
December and then declined for both ponds (Table 2) . North
Pond (with sewage effluent) maintained generally higher pop-
ulations with one notable exception: C. aapitata standing
crops peaked at the same level in both ponds (62.8 g/m2 wet
weight in North Pond compared with 62.4 g/m2 wet weight in
South Pond).
The two amphipod populations varied inversely between ponds
(Table 2). A. conferviaolus populations showed a continu-
ous buildup in North Pond to the end of the experimental
period with very few organisms occurring in South Pond.
C. epinicorne, on the other hand, started with large
populations in South Pond which continually decreased to
total disappearance by December. Very few C. spinicorne
were found in North Pond transect samples.
An unexpected relationship between A. eonfervicolus and
P. ciliata was noted. Both numbers and weights showed
high positive correlations between these two species
(0.42 and 0.52 respectively). Both species also showed
increases in number with decreases in surface temperature
and salinity (Allen and Dennis3). The correlation could
be by chance and should be investigated further.
The total disappearance of the benthos on South Pond mud by
December remains unexplained. I sampled water properties
in January and found low dissolved oxygen directly over
the South Pond mud substrate only (Table 3). This strongly
suggested a non-uniform mixing resulting in low DO 's as a
possible cause for the disappearnace. Populations on other
substrates in South Pond seemed uneffected.
Effects of Fish on Standing Crop
No significant difference existed between samples taken
inside and samples taken outside of the fish exclusion
pens in this study. The lack of survival of salmonids
in the initial experiments (Exp. IA, Allen and Dennis3)
518
-------
Table 1. Frequency of occurrence of benthic animals taken by
two methods of sampling of fauna developed between
July 1971 and January 1972 in two marine aquaculture
ponds, one fertilized with treated wastewater.
Kind of Animal Frequency.of Occurrence
_ . Transect Sampling Basket Sampling
Group Species (N=5Q) H y (N.48)
Polychaete worms
Gammarid
amphipod
Capitella aapitata
Polydora ail-iota
Anieo gammer us
aonfevv-ioolue
97.9
47.9
43.7
83.3
83.3
79.2
Corophium epinioorne 33.3 52.1
Bryozoans undetermined, but common
Isopod (Plabellifera) 2.1 4.2
Barnacle Balanue opp. 4.2
Hollusk Lyoneia aal-iforniaa 4.2
Fish GaeteroeteuB
aauleatus 4-2
(stickleback)
579
-------
Table 2. Monthly average number and wet weight in grains per
square meter of four major species of benthic animals
taken in transect sampling of North and South Ponds,
September 1971 to January 1972.
Species
Capitella
capitata
Polydora
ciliata
Anisogammerue
eonfarvico lus
Corophium
epinieorne
TOTAL
Capitella
capitata
Polydora
ciliata
Anieogammerue
eonferviaolue
Corophium
epiniaorne
TOTAL
Pond
? Sep 71
North 76
0.5
0
0
102
1.1
76
1.1
254
2.7
South 0
0
0
0
51
0.3
2548
8.0
2599
8.3
Date
5 Oct 71
3456
23.4
382
2.6
127
3.9
25
0.8
3990
30.8
1376
4.6
1147
2.8
25
0.5
2140
2.0
4688
9.8
of Sampling
4 Nov 71 6
9019
62.8
1401
9.9
688
11.1
0
0
11108
83.9
14726
62.4
408
0.7
229
5.7
1019
1.8
16382
70.7
Dec 71
6624
43.3
5299
32.7
1274
8.3
0
0
13197
84.4
0
0
0
0
0
0
0
0
0
0
7 Jan 72
1962
13.4
3566
12.7
3745
8.7
0
0
9273
34.8
0
0
0
0
0
0
0
0
0
0
520
-------
Table 3. Comparison of dissolved oxygen in water near pond
bottoms with surface water near headgates on
7 January 1972.
Sampling Location
North
Pond
South
Center of Exclusion Pens:
Mud
Sand
Gravel
Shell
13.8
15.0
15.6
14.4
22.0
15.0
12.8
11.6
Distance in meters from
headgate along transect
10
20
30
40
Headgate-surface
10.4
12.2
13.2
15.0
12.4
6.2
1.2
2.0
15.0
16.2
527
-------
and the short exposure time of the samples to surviving
salmonids in the later experiments (Exp. IB) may account
for this. Larval marine fish introduced with bay waters
could pass freely through the mesh used for exclusion pens
and thereby negated studies designed to measure the effect
of salmon predation on benthos.
Organisms on Different Substrates
Only two species were found to vary significantly with sub-
strate (polychaete, C. eapitata; and gammarid amphipod,
A. confervicolus-, Table 4) .
C. eapitata had the largest standing crops on sand with an
average of 348 organisms/sample. Since sand tended to be in
shallower water than other substrates, depth of the water
column could have been a factor in the success of C.
eapitata on a sand substrate. Gravel supported only 54
organisms/sample. Mud and shell showed no difference in
standing crop with populations between 12 to 13 organisms/
sample. This result has been somewhat biased by the total
mortality on South Pond Mud.
A. eonfervicolus standing crops were largest on oyster shell
or gravel, (31-38 organisms/sample); no significant differ-
ence was found between these two substrates. Mud and sand
were shown to support equal populations averaging 6 to 7
organisms/sample. Particle size appeared to be a factor.
High crops on shell could have resulted from sampling bias
due to water filtration through sampler screens preventing
escapement since shell did not completely fill the entire
sampler as did other substrates. These results should be
retested as trap sampling on this species showed different
results (Pollard1°).
Total biomass was highest on the shell substrate (115g wet
wt/M2) due to heavy incrustation by P. ciliata and the
presence of A. confervicolus. This was followed by sand
(86 g wet wt/M2), then gravel (71 g wet wt/M2) and finally
mud (45 g wet wt/M2).
Differences in Benthos between Ponds
The two species, P. ciliata and ^4. confervicolus, had
significantly higher populations in North Pond (with
sewage effluent) than in South Pond (a tidally flushed
estuarine pond) (Table 4). P. ciliata standing crop in
North Pond was 128 organisms/sample compared with 1
organism/sample in South Pond; A eonfervicolus populations
522
-------
Table 4.
Mean numbers of benthic organisms per basket sampler
for factors within significant treatments (pond, sub-
strate or exclusion pen). Significance of treatment
determined by a Three-way Analysis of Variance.
Significance of factors within a treatment determined
by a Student-Newman-Kreuls Test (Sokal and Rohlf8).
Treatment
Species
Mean numbers/Sampler*
North Pond vs.
South Pond
Polydora
ciliata
Anisogammerus
confervicolus
South Pond
1
2
North Pond
128
77
Substrate:
Samples from
both ponds
combined
Capitella
oapitata
Anisogammerus
aonfervicolus
Mud
12
Shell
14
Sand
6
Mud
7
Gravel
54
Gravel
31
Sand
348
Shell
38
*Values underlined are not significantly different from each
other at the 5% probability level.
525
-------
were 77 organisms/sample and 2 organisms/sample respectively.
C. aapitata and C. spinioorne standing crops did not differ
between ponds, with C. aapitata having large populations
and C. spinieorne having extremely low populations.
In terms of total biomass North Pond supported a much larger
standing crop (159 g wet wt/M2) than South Pond (35 g wet
wt/M2). For all in-place basket samples, the standing crops
I found after about 145 days of rearing ranged from zero in
South Pond sand to 195 gms wet wt/M2 in North Pond shell
(Table 5).
COMPARISONS WITH OTHER BENTHIC STUDIES
The results obtained for average total biomass in each pond
were compared with several benthic studies (Table 6). North
Pond had standing crops greater than or equal to standing
crops of freshwater ponds fertilized with commercial fertil-
izers (Liang11)/ and standing crops larger than those found
in the adjoining bay (Carrin5), Buzzards Bay (Sanders12),
or the English Channel (Holme13). On the other hand, North
Pond's benthic biomass was smaller than that found in a con-
tinuous flow pond (Hanks6), for an arctic macoma community
(Ellis11*), and for certain intertidal areas (Sanders, et
al15).
The South Pond had a standing crop equal to that found in
unfertilized freshwater ponds (Liangri)/ but lower than
standing crops of all other studies considered.
Powers, in his study of the amphipod A. confervieolus in
the aquaculture ponds used mathematical models and estab-
lished a carrying capacity of 300,000 amphipods per pond or
200 amphipods/M2 (Powers1t). This study shows standing
crops of much higher magnitude existing for long periods
of time in the ponds. On each of the substrates in each of
the ponds, A. confervioolus standing crops between 2000-
12,000 organisms/M2 commonly occurred. Powers, however,
studied the ponds under a different set of conditions
(Exp. Ill, Allen and Dennis3).
DISCUSSION
At present, when sewage-effluent mixtures are used in the
fish ponds, they are run as a static system. If ponds
were to be fertilized periodically with both bay water and
effluent, say every 3 to 4 weeks, benthic standing crops
might improve in biomass and species density. I would be
interested in seeing the effect of such a program.
524
-------
Table 5. Comparison in total numbers and weight per square
meter of benthic biomass as taken in basket samples
on four substrates between North and South Ponds
(6 samples from four substrates in each pond -
48 total).
Substrate
pond
rmd
sand
gravel
shell
Total Number/M2
South Pond
6500
21400
2900
1800
Weight in graras/Ms
Dry
12
7
6
Wet1
Pond
mud
sand
gravel
shell
North Pond
28000
23500
25500
22700
40300
22
16
19
18
34
159
90
106
102
195
35
66
41
35
Calculated from dry weight by wet weight conversion factors
for polychaetes and amphipods as listed in Thorsen9.
525
-------
Table 6. Comparison of North and South Pond biomass with
some values reported in the literature.
Author
Holme11
Sanders1 *
Sanders,
et alls
Carrin*
Ellis1*
Banks'
Liang11
Present Study
Location and Habitat
English Channel
Buzzards Bay, Mass.
Barnsdale Harbor, Mass.
(Intertidal)
North Humboldt Bay, Calif.
Arctic tnacoma community
Estuarine constant flow pond
Unfertilized freshwater pond
summer
winter
Fertilized freshwater pond
summer
winter
Marine Aquaculture Ponds,
Arcata, Calif.
North
South
Weight (g/M* }
Dry
11.2
12.3
17.6-60.0
136
9.2
7.0
22.4
8.6
21.9
6.2
Wet
55
105
200
1360
159
35
526
-------
With the proper stabilization and aerating system, the
benthic standing crops of the ponds could conceivably be
manipulated toward the important fish food items such as
A. confervieolus and away from seemingly "weed species"
such as C. eapitata. Toward this end, I would suggest that
a slight covering of the mud substrate (and perhaps even
the sand) with oyster shell or gravel might reduce C.
oapitata habitat and improve A. oonfervioolus habitat.
Shell appears to be doing the intended function of
providing shelter to amphipods. Further studies should
be done on A. confervieolus population dynamics and its
relationship to salmonid feeding habits.
It is of interest that the ponds are classified as
"polluted" by standards applied to non-aguacultural marine
environments (Reisch17).
LITERATURE CITED
1. Allen, G. H. 1970. The constructive use of sewage,
with particular reference to fish culture. FAO
Technical Conf . on Marine Pollution and Its
Effects on Living Resources and Fishing. FIR:
MR/70/R-13.
2. Darnell, R. M. 1961. Trophic spectrum of an estuarine
community, based on studies of Lake Pontchar train,
Louisiana. Ecology 42:553-568.
3 Allen, G. H. and L. Dennis. 1974. Report on pilot
aquaculture system using domestic waste waters
for rearing Pacific salmon smolts (This conference) .
4 Sharp, T. R. 1974. Benthic Fauna standing crops in
estuarine aquaculture ponds using reclaimed water.
M. S. Thesis in Fisheries, Humboldt State Univer-
sity, June.
5 Carrin, L. F. 1973. Availability of invertebrates as
shorebird food on a Humboldt Bay mudflat. M. S.
Thesis in Wildlife, Calif. State University,
Humboldt.
Hanks, Robert W. 1968. Benthic community formation
Hanks woe environment. Cheasapeake
Science. Vol. 9, No. 3:163-172.
ar.rioT-.5on R 0. 1959. A modified flotation technique
Ande^°n;oR;i°g bo;tom fauna samples. Limn, and Ocean.
4:223-235.
527
-------
8. Sokal, R. R. and F. J. Rohlf. 1969. Biometry; the
principles and practice of statistics in biolog-
ical research. W. H. Freeman and Co., San
Francisco. 776 pp.
9. Thorsen, G. 1957. Bottom Communities. In:Treatise
on Marine Biology and Daleoecology, Vol. I. ed.
J. W. Hedgpeth. Geological Society of American,
Memoir 67. pp. 461-534.
10. Pollard, Robert, 1972. A catch per unit effort study
on a population of Amisogammei'us confervicolus in
a saltwater pond fertilized with sewage. Under-
graduate field study in Fisheries, Calif. State
University, Humboldt, (unpublished).
11. Liang, J. K. 1966. Benthic fauna of fertilized and
unfertilized ponds in winter. In: Proceedings of
World Symposium on warmwater pond fish culture.
FAO Fish Dept. 441(3):82-94.
12. Sanders, H. L. 1960. Benthic studies in Buzzards
Bay. III. The Structure of the soft-bottom
community. Limn, and Ocean. 5(2) :138-153.
13. Holme, N. A. 1953. The biomass of the bottom fauna
in the English Channel off Plymouth. J. Mar. Biol.
Ass. U.K. 32:1-50.
14. Ellis, D. V. 1960. Marine infaunal benthos in Arctic
North America. Arctic Institute of North America,
Tech. Paper No. 5:1-53.
15. Sanders, H. L., E. M. Goudsmit, E. L. Mills, and G. E.
Hampson. 1962. A study of the intertidal fauna
of Barnstable Harbor, Mass. Limn, and Ocean.
7(1) -.63-79.
16. Powers, J. E. 1973. The dynamics of a population of
Anisogammerus confervicolus (Amphipoda) : A
computer simulation. M. S. Thesis in Fisheries,
Calif. State University, Humboldt. Ill pp.
17. Reisch, D. J. 1973. The use of marine invertebrates
as indicators of varying degrees of marine pollu-
tion and sea life, ed: Mario Ruivo. FAO. Fishery
News (Books) Ltd. Surrey, England. pp. 203-207.
528
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CONTROLLED EUTROPHICATION: SEWAGE TREATMENT
AND FOOD PRODUCTION
by
J. Glenn Songer*, N.M. Trieff*, Rodney F. Smith**,
and Dov Grajcer***
INTRODUCTION
Natural ecosystems can produce no more than two metric tons per hectare
per year of animals useful to man on a sustained and reliable basis.
Commercial yields, greater than natural yields by 100 times, are
achieved in artificial systems in which animals are provided with food
and flowing water under carefully controlled conditions. A combination
of natural and artificial systems, utilizing the best aspects of each,
yields the approach toward food production and waste treatment known as
"controlled eutrophication."!
The essential feature of controlled eutrophication is the physical sep-
aration and compartmentalization of the producer and consumer levels of
the community.! An example of this is the growth of phytoplankton (a
freshwater species of Chlorella) and, subsequently, bivalves.2
A pond one meter deep provides enough carbon dioxide for algal growth
year-round. Seawater contains, naturally, a quantity of carbon dioxide
in the form of dissolved carbonates and bi carbonates J Free exchange
with the atmosphere is an additional source.
Several sources of mineral nutrients are available. Commercial fertili-
zer is capable of providing the necessary nitrogen, phosphorus, and
other nutrients, but is quite expensive.' Artificial upwelling of the
ocean is also quite costly, but is, nevertheless, very effective; a
pilot project utilizing artificial upwelling has been in operation at
Saint Croix, Virgin Islands, for some time.3
A third and probably more obvious source of nutrients is raw or treated
sewage. The algae growing ability of sewage is well known from labora-
tory, pilot plant, and full-scale waste stabilization ponds. Reported
yields have been tremendous. »5
* Department of Preventive Medicine and Community Health, University
of Texas Medical Branch, Galveston, Texas
** Microbiology Laboratory, Alta Bates Hospital, Berkeley, California
*** Head, Aquaculture Research, Syntex Corporation, Palo Alto, Calif.
529
-------
Dunstan and Menzel6 have worked with sewage as the nutrient supply for
continuous culture of algae. The high nutrient level in sewage allows
for a considerable dilution which is necessary to accomodate the salt
tolerance of marine algae. The algae is fed to herbivores; the herbi-
vores then become food for man, or alternately, are fed to a primary
carnivore and the nutrients harvested at a higher trophic level.
A system has been developed on the laboratory scale involving the use
of the marine alga Tetraselmis for controlled eutrophication of raw
sewage. The subsequent algal proliferation was fed to brine shrimp,
Artemia salina. Net products of the system were reported as (1) brine
shrimp for use as fish food or shrimp food and (2) a purified effluent.7
The brine shrimp were adaptable to life in raw sewage in which an algal
bloom had taken place. Recommendations for optimal treatment of raw
sewage on this scale are (1) algal growth with artificial light, (2)
addition of Artemia, (3) decantation and additional algal growth, and
(4) final decantation.
Reductions by the process of such parameters as total suspended solids,
five-day BOD, turbidity, odor, orthophosphate, nitrate, nitrite, and
ammonia were to levels equivalent to those achieved by conventional
secondary and perhaps tertiary treatment.
The objective of the present research is to further study and develop
this system. The design of a continuous-flow system is undertaken. In
addition, various water quality parameters are studied and the passage
of certain bacterial groups through the system is examined in detail.
Water quality parameters chosen for study are: BOD, total solids (res-
idue on evaporation), total inorganic phosphorus, and total Kjeldahl
nitrogen; bacteria chosen were coliforms, enterococci, Salmonella,
Shigella, Vibrio alginolyticus. and Vibrio parahaemolyticus.
It is hypothesized that improvements in all water quality parameters
will approach or surpass required reductions (i.e., a non-polluting
effluent will result). Coliform bacteria will be reduced to less than
one per cent of raw sewage concentrations, as will enterococci. Sal-
monella and Shigella will not be detected. No halophilic Vibrios"wTn
be isolated at any stage.
MATERIALS AND METHODS
Continuous-flow System
The initial work was done using a static set-up. A continuous-flow
system was designed and built for use in the present research.
Lighting - Cool-white fluorescent lighting was used (Westinghouse).
Three 1*2 cm, two-tube fixtures with 40 watt tubes were wired in para-
llel , side by side.
550
-------
Raw Sewage - Raw sewage was obtained weekly from the main sewage treat-
ment plant in Galveston and was stored in a 20-liter Pyrex carboy.
Synthetic Sea Salts - Instant Ocean (Aquarium Systems, Inc., Eastlake,
Ohio, 44094) was used. It was mixed to yield a salinity of 40 o/oo and
stored during use in a 125 liter Rubbermaid trashcan.
Algae and carboy for culture - The marine alga Tetraselmis chui was ob-
tained from the stock cultures of the National Marine Fisheries" Service,
Gulf Coastal Fisheries Center, Galveston, Texas, through the courtesy
of Loretta Ross. The culture was maintained in a 20-liter Pyrex carboy.
A rubber stopper with a 40 cm length of 15 mm OD glass tubing inserted
into it was placed in a 2.5 cm hole in the bottom of the carboy, the
tubing rising to such a point inside the carboy as would allow for re-
tention of a maximum volume of 18 liters. This tube thereby provided
an automatic overflow. Continuous aeration was used.
Brine Shrimp and Hatching - Brine shrimp (Artemia salina) eggs were ob-
tained from California Brine Shrimp, Inc., Menlo Park, California,
94025. The eggs were hatched in a circular dish (25 cm diameter, 7.5 cm
depth) according to the method of Needham,^ collected with a large-
tipped pipet, and transferred to the culture container. An aquarium
(20 cm height, 32 cm width, 76.5 length) was used as a permanent con-
tainer for the brine shrimp.
Pump - Raw sewage, Instant Ocean, and the effluent were pumped with a
Buchler Polystaltic Pump (Buchler Instrument Company, Fort Lee, N.J.,
07024). The tubing was Tygon, 1.60 mm ID. Continuously variable flow
rates from 2.5 ml/hour to 1000 ml/hour were available.
These components were assembled into the system shown in Figure 1. The
lights were suspended 10 cm above the algal culture. Operation of the
lights was on a full-time basis. A turnover rate in the algal culture
of 50% per day was desired, so the pumping rate was adjusted to give a
combined flow of raw sewage and Instant Ocean amounting to 6.25 ml per
minute or 9 liters per day into the algal culture.
Water Quality Parameters
Sampling - Samples were taken by pipet at the various stages (raw sew-
age, algal culture, and effluent) and subjected to the tests.
Biochemical Oxygen Demand - Determinations were done according to Stan-
dard Methods for the Examination of Mater and Wastewater.9 Various
dilutions were used, depending upon the expected order of magnitude of
the BOD value. Dissolved oxygen measurements were done by the membrane
electrode method using an Edmont Oxygen Analyzer (Model 60-625, Edmont-
Wilson, Coshocton, Ohio, 43812).
537
-------
Total Solids (Residue on Evaporation) - Liquid samples (100 ml) were
evaporated to dryness in vacuo, in preweighed flasks. Weight of resi-
due in mg/1 was determined by reweighing, subtracting the initial value,
and multiplying by 10.
Total Inorganic Phosphorus - Determinations were done according to Stan-
dard Methods for the Examination of Water and Wastewater,^ using the
aminonaphtholsulfonic acid method.
Total Kjeldahl Nitrogen - Determinations were done according to Standard
Methods for the Examination of Water and Wastewater.9 The procedure was
that for organic nitrogen, omitting the ammonia removal step. The iso-
lated nitrogen was determined by titration.
Bacterial Groups
Except there otherwise stated, incubation was at 37°C for 48 ± 3 hours
and all media was from Baltimore Biological Laboratories, Cockeysville,
Maryland, 21030. Samples were taken at the various stages (raw sewage,
algal culture, and effluent) and subjected to the various tests.
Coliforms - An MPN/100 ml was determined by the multiple tube fermenta-
tion technique using lauryl sulfate broth. Transfers were made from
positive tubes to EC broth; incubation was at 44.5°C in a water bath.
Growth and gas in 24+2 hours indicated the presence of fecal coliforms
and confirmed the MPN.
Enterpcocci - Azide dextrose broth served as a primary medium yielding
an MPN/100 ml. Positives were transferred to ethyl violet azide broth.
Turbidity and the appearance of a purple button constituted a positive
test; streaks were made to Columbia CNA blood agar (composed of Columbia
CNA agar base containing colistin and nalidixic acid with 5% sheep blood
added;. Typical colonies were picked to Enterococcosel broth where
blackening of the medium in 24 ± 2 hours gave a completed test and con-
firmed the MPN.
Salmonella and Shi gel!a - Growth in Selenite-F broth was considered a
positive presumptive test; streaks were made to MacConkey agar. Typi-
cal colonies were picked to Kligler's iron agar slants and incubated
for 18 hours. Cultures giving reactions typical of Salmonella or Shig-
ella were subjected to biochemical testing in the API-20 Profile Recog-
TnTTon System (Analytab Products, Inc., New York, N.Y., 11514). A cor-
rect profile confirmed the presence of Salmonella or Snivella.
Vibrio parahaemolyticus and Vibrio alginplyticus - Enrichment cultures
fin alkaline peptone broth from Difco Laboratories, Detroit, Michigan,
48232) were streaked to TCBS agar. Appearance of typical colonies in
24 hours indicated the presence of Vibrios. Suspect colonies were sub-
jected to biochemical tests, again using the API-20 Profile Recognition
532
-------
System. Three per cent NaCl water was used as diluent. A correct pro-
file confirmed the presence of V. parahaemlyticus (#4346106) or V. al-
ginolyticus (#4146124). " - —
RESULTS AND DISCUSSION
Water Quality Parameters
BOD analysis of raw sewage yields the comparatively high and variable
values normally associated with it (Figure 2). Samples from the algal
culture compare closely with raw sewage in BOD values. This is reason-
able, since sewage organics are simply converted, for the most part,
into algal cells. Effluent BOD's (average 64.7) are somewhat higher
than expected, but represent a considerable improvement over raw sewage
(average 76.5% removal of BOD).
Interpretation of the measurements of total solids (Figure 3) is con-
fused by the fact that the carrying water (Instant Ocean) contains an
average of 45,014 mg/1 of residue on evaporation. A correction factor
of 22,507 mg/1 to account for the contribution from the Instant Ocean
was applied to each of the measurements of total solids in the algal
culture and effluent (i.e., 45,014 divided by 2, since Instant Ocean and
raw sewage were mixed 1:1). This yielded the corrected lines (Figure 4)
which show a consistent increase in this parameter from raw sewage to
effluent. The increase between raw sewage and the algal culture is pro-
bably attributable in part to the presence of algal cells and also to
some slight evaporation. The subsequent increase in the effluent is
believed to be almost wholly attributable to evaporation. Measurements
indicate nearly a 5 o/oo increase in salinity alone from the 1:1 mixture
of raw sewage and Instant Ocean to the effluent. Since it is virtually
impossible to control evaporation, measurements of this parameter inevi-
tably face the need of correction and must be interpreted on that basis.
The data for total inorganic phosphorus shows a pattern which is often
observed in stabilization ponds (Figure 5). Phosphates (ortho- and
poly-) in raw sewage are removed by algae, by incorporation into cell
material and/or by precipitation (due to high pH). In the effluent,
the phosphorus concentration increases, probably due to a pH drop in the
brine shrimp tank. Also, brine shrimp fecal pellets settle out and
likely contribute to the concentration of dissolved phosphorus by verti-
cal exchange as they are broken down by phosphatizing bacteria. Per
cent removals in the algal culture averaged 65.5%, but the high was
81.5%. The decrease, from raw sewage to effluent, averaged 39%, and
effluent values (average 5.07 mg/1) are somewhat lower than those repor-
ted by Neel^° in a report on the operation of a stabilization pond
sy s tern.
Total Kjeldahl nitrogen values (Figure 6) are quite different from those
expected. Extremely low values in raw sewage measurements indicates
533
-------
extensive denitrification and either loss as nitrogen gas or oxidation
to nitrites and nitrates. The drop in total nitrogen values for the
algal culture is likely due to settling out of many sewage organics and
further oxidation of nitrogen compounds (an insufficient concentration
of phosphorus leads to nitrogen excess with subsequent conversion to
nitrites and nitrates). Effluent values are somewhat elevated from
those of the algal culture; nitrogenous wastes of the brine shrimp are
probably the greatest contributors to this increase. Remnants of algal
cells suspended in the water, as well as numerous small brine shrimp,
could not be removed before making determinations and no doubt contribu-
ted substantially to the values.
Bacterial Groups
Figure 7 shows the MPN/100 ml values for coliforms at various stages of
treatment. As expected, a disappearance of fecal coliforms is evidenced
on passage of raw sewage through the system. Figure 8 shows similar
patterns for the enterococd. No serotypes of Salmonellae of Shigellae
were detected at any stage (Table 1).
Vibrio alqinolytlcus was detected in the effluent, but at no other point
In the system. Infiltration of seawater (at exceptionally high tides)
into Galveston's sewage treatment plant is the most probable explanation
for its presence. The environment 1n the brine shrimp tank is favorable
for its multiplication.
CONCLUSIONS
This research has yielded valuable baseline data for further study of
this sewage treatment system. The incorporation of a continuous-flow
system into previously static laboratory studies has helped to emphasize
some of the problems which may be incurred in a scale-up to pilot plant
size.
Further study of raw sewage is needed to determine the presence of phy-
totoxic compounds. It is apparent that a build-up of such substances
occurs, since great reductions in the algal population were observed
from time to time. A unicellular alga (such as Tetraselmis chul used
here) is best for consumption by brine shrimp, but It may be that a
mixed culture of marine dinoflagellates will respond better to the
stresses incumbent in using raw sewage as a nutrient source. Experi-
ments to test this are in preparation.
The applicability of this system to sewage treatment and food production
is, for the most part, certain. Further work is necessary, however, to
optimize conditions for treatment of sewage and multiplication of brine
shrimp.
534
-------
Previous research on this system included the use of a second algal
culture to remove wastes of the brine shrimp. The elimination of this
step simplifies the procedure considerably, but additional treatment is
apparently required to further improve the quality of the effluent.
System modifications are being studied at present to overcome this and
other problems, including, perhaps, a "mopping up" stage, as reported
by Rhyter.'
Effluent BOD values, though much improved over raw sewage, are somewhat
above the standard required of secondary treatment plants (i.e., 20
mg/1). This required value is certainly approachable, if not surpas-
sable, by this system, perhaps if an additional passage through an algal
culture were performed.
A better method must be devised for the study of inorganic salts (total
solids) for reasons previously discussed. The potential for solids
removal cannot be assesed without a correction for the salinity of the
carrying water, as well as an allowance for evaporation.
Total inorganic phosphorus values are affected by a number of factors
which should be controlled. A careful monitoring of pH in the algal
culture and brine shrimp tank should yield information on the precipi-
tation-dissolution of phosphates. Design changes in the system should
include a method for removing solid wastes of brine shrimp from the
brine shrimp tank. This should eliminate the loss of phosphorus from
bottom sediments to the effluent. Possible uses of the sediment as a
fertilizer are being investigated.
Inability to maintain a continuously fresh supply of raw sewage is in
large part responsible for the low total Kjeldahl nitrogen values. At
least, initial studies should be done on the relationship between
nitrite-nitrate and ammonia-organic nitrogen. An increase in concen-
tration of nitrite-nitrate or even their presence in notable quantities
would be an unexpected finding if raw sewage were kept fresh. This is
true since denitrification is normally limited to the ammonia stage
in the presence of active algal growth.
The bactericidal effect of this treatment is obvious. Elucidation of
the mechanism which brings about bacterial demise would be of help in
controlling system operation.
535
-------
LITERATURE CITED
1. Rhyter, John H., W.M. Dunstan, K.R. Tenore, and J.E. Huguenin.
Controlled Eutrophication-Increasing Food Production From the
Sea by Recycling Human Wastes. Bioscience. 22:144-152,
March, 1972.
2. Tamiya, H. Mass Culture of Algae. Ann. Rev. Plant Physiol. 8;
309-334, 1957.
3. Roels, O.A., and R.D. Gerard. Artificial Upwelling. Marine Tech.
Soc. Proc. Conf. Food-Drugs From the Sea. 102-122, 1970.
4. Gotaas, H.B., W.J. Oswald, and H.F. Ludwig. Photosynthetic Recla-
mation of Organic Hastes. The Scientific Monthly. 79:368-
378, 1954.
5. Rhyter, John H. Potential Productivity of the Sea. Science.
130:602-608, September 11, 1959.
6. Dunstan, W.M. and D.W. Menzel. Continuous Cultures of Natural Popu-
lations of Phytoplankton in Dilute, Treated Sewage Effluent.
Limnology and Oceanography. 1_6:623-632, July, 1964.
7. McShan, M., N.M. Trieff, and Dov Grajcer. Biological Treatment of
Sewage Using Algae and Artemia. JWPCF. In press, 1974.
8. Needham, J.G., P.S. Galtsoff, F.E. Lutz, and P.S. Welch. Culture
Methods for Invertebrate Animals. New York, Dover Publica-
tions, 1937, 590 pp.
9. American Public Health Association, American Water Works Associa-
tion, and Water Pollution Control Federation. Standard
Methods for the Examination of Water and Wastewater. Washing-
ton, American Public Health Association, 1971, 874 pp.
10. Neel, Joe K., J.H. McDermott, and C.A. Monday, Jr. Experimental
Labooning of Raw Sewage at Fayette, Missouri. JWPCF. 33:
603-641, 1961.
ACKNOWLEDGEMENT
This research was supported by the James W. Mclaughlin Fund, University
of Texas Medical Branch, Galveston, Texas
536
-------
Effluent
t
Peristaltic
Pump
t
Raw
Sewage
t
Instant
Ocean
\
ft
Algal
culture
Brine shrimp tank
o
o
o
o
o
o
o
SCHEMATIC OF CONTINUOUS - FLOW SYSTEM
Figure 1
537
-------
u>
CO
BIOCHEMICAL OXYGEN DEMAND (mg/l)
3r
"
X
o - Raw Sewage
• -Algal Culture
A -Effluent
S.E.-Standard Error of the Mean
2 3
Experiment Number
)?± one S.E.
Figure 2
-------
<0
TOTAL SOLIDS (RESIDUE ON EVAPORATION) (mg/l)
5r
e
o>
o
II
x
o - Raw Sewage
• - Algal Culture
A - Effluent
S.E. - Standard Error of the Mean
Experiment Number
± one S.E.
Figure 3
-------
Ol
CORRECTED VALUES : TOTAL SOLIDS
(RESIDUE ON EVAPORATION) (mg/l )
o>
o
ti 2
X
o - Raw Sewage
• - Algal Culture
* - Effluent
S.E. - Standard Error of the Mean
234
Experiment Number
± one S.E.
Figure 4
-------
TOTAL INORGANIC PHOSPHORUS (mg/l!
i.o
0,8
O> 0.6
E
o>
o
II
X
0.4
0.2
o - Raw Sewage
• - Algal Culture
a - Effluent
S.E. - Standard Error of the Mean
1234
Experiment Number
5? ± one S.E.
Figure 5
547
-------
TOTAL KJELDAHL NITROGEN (mg/I)
2
"v
o»
E
o>
JO
II
X
o- Raw Sewage
• - Algal Culture
*- Effluent
S.E.- Standard Error of the Mean
5
I
1234
Experiment Number
X± one S,E.
Figure 6
-------
COLIFORM MPN / 100ml
10
° - Raw Sewage
• - Algal Culture
* - Effluent
S.E.- Standard Error of the Mean
o
II
X 4
Experiment Number
Figure 7
X one S.E.
543
-------
ENTEROCOCCI MPN / 100 ml
o - Row Sewage
• - Algal Culture
«. - Effluent
S.E. - Standard Error of the Mean
I 3
o>
o
234
Experiment Number
X ± one S.E.
Figure 8
544
-------
s
Organism
Salmonella
Shigella
V. parahaemolyticus
V. alginolyticus
Raw sewage
0/4
0/4
0/4
0/4
LOCATION
Algal culture
0/4
0/4
0/4
0/4
IN SYSTEM
Effluent
0/4
0/4
0/4
3/4
Brine shrimf
0/4
0/4
0/4
1/4
Table 1: NUMBER OF SAMPLES YIELDING POSITIVE TESTS/NUMBER OF SAMPLES TESTED
-------
PRINCIPLES OF SEWAGE TREATMENT THROUGH
UTILIZATION IN FISH PONDS *
by
Erno Donaszy **
LITERATURE SURVEY
More and more planners are suggesting that sewage could
be used as food in commercial fish ponds. However,
these same ideas were expressed by fisheries managers in
the hopes of increasing fish production. Certain waste
waters (sewage) replace organic fertilization and
increase the fish food supplies and in turn the natural
Field of the fish pond. The disposal of waste water
sewage) through irrigation is in an advanced state.
We have already examined irrigation plants and the
guiding-^principles for these plants are being developed.
Balogh gave an account of putting waste water to use.
He writes that "The effluent from waste water spray-
treatment plants as well as from other treatments contain
a certain amount of soluble nutrients.*1 Commercial fish
ponds were established, in Germany, for the utilization
of such water. Small organisms utilize the remaining
nutrients. They in turn serve as fish food thus
increasing the fish yield of the pond. However, such
clarified (pre-treated) waste waters are poor in oxygen.
Therefore the ponds are not fed solely with treated waste
water but with a mixture of fresh and waste water in a
1:3 ratio.
dealt 5with this question in 1953 when following
Imhoff's ? lead we began investigating the problems of
carp fisheries. Imhoff dealt with carp Cyprinus carpio
** National Agricultural Quality Control Institute,
Budapest, Hungary.
* Original title;Donaszy, Erno. 1965. A halastavas
szennyviztisztitas elvi kerdesel. Hidrologiai Kozlony.
4:173-177.
Translated from Hungarian by G. Teleki, 1971.
Fisheries, Humboldt State University. Present address:
Box 429, Ontario Ministry of Natural Resources,
Port Dover, Ontario, Canada, Special assistance by
S. Teleki, Toronto, Canada.
545
-------
and tench Tinea yulgaris fisheries in sewage ponds, i.e.
ponds built for the purpose of sewage disposal. Imhoff
suggested that in the situation similar to the above a
five fold dilution should be used. If no diluent is
used only Foxinus foxinus and Gasterosteus aculeatus etc.
can be brecHIn existing ponds fish production is the
primary objective.
Prerequisites of waste water utilization are: The oxygen
content of the lake water must remain normal; the
aquatic flora must be controlled since extremely large
populations consume the lake nutrients (primarily Og) at
an accelerated rate resulting in sudden die offs of
organisms; only fish with low oxygen requirements (carp
Cyprenus carpio and tench Tinea vulgaris) should be
stocked.The waste water should be cleared of mud and
diluted with natural fresh water. Waste water should not
be introduced into lakes fed solely by rain water. The
dissolved oxygen may not fall below 3mg/l. One should be
able to shut off the waste water supply at any given time,
e.g., when harvesting the fish or drying and disinfecting
the pond bottom.
According to Imhoff, a one hectare (2.4-7 acres) fish
pond would be sufficient to purify sewage of 2000 people.
In the case of a 5 fold dilution, with water depth of at
least i meter, 5m2 of pond area are necessary per person
as opposed to 20mz in the case of the 1 hectare pond.
Imhoff says that natural bacteriological purification of
the waste water is better than artificial sewage treat-
ment. However, Imhoff is concerned primarily^with sewage
treatment and not fish breeding. Woynarovich using some
of Imhoff's data discusses the establishment of a sewage
fishery in Hungary.
1. He feels that the one hectare per 2000 inhabitants
should not be limiting sewage treatment to that
small an area.
2 He feels that the question of the diluent can be
solved even if sufficient fresh water cannot
be obtained. Since the specific gravity of sewage
is greater than water the undiluted sewage would
sink to the pond bottom, begin decaying, upsetting
the lake's biological balance. Woynarovich also
states that the diluent can be one-part recycled
water if the lake water is too warm to be added
to the effluent. These problems, states
Woynarovich, can only be solved by practical
experimentation.
547
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THE EXAMINATION OF FISH PONDS
SUPPLIED WITH WASTE WATER
In Hungary there are no fisheries established specifi-
cally for sewage water purification. The personnel of
the National Health Institute examined a number of
commercial fish ponds and small natural lakes. They
introduced an effluent into these waters2to determine
if the sewage presented a health problem >;>. Based on
24-hour examinations of the sewage-supplied fish ponds
in Balatonfoldvan on June 19 and 20, 1962, Csanady and
co-workers2 established the following: The pond
contained 250 inhabitant-equivalents of sewage per 1
1 Katasztralis Hold (KH or cadastral yoke = 1.412 acres).
This quantity of sewage could be effectively decomposed
by the pond's organisms. The dilution was only 2:2 yet
there were no adverse effects noted in the open water.
However, at the effluent outfall an aerobic condition
prevailed. Oxygen in the open pond waters was abundant
especially during mid-day. The biologically processed
sewage of the Balatonfoldvan sewage plant is pumped into
these ponds. The Balatonfoldvan hydrologists stated that
the biological purification treatment was quite ineffi-
cient. A double layered sedimenter would insure the
sedimentation of parasite eggs. In the opinion of the
plant managers, purification of waste water in the sewage
plant can only be considered a good mechanical but only
partial biological purification. The decomposition is
actually completed in the pond.
Csanady and Gregacs^ have conducted investigations of the
sewage plant of Balatonfoldvan and several lakes into
which sewage was introduced. They found that partially
purified household sewage did not appreciably disrupt
the lake's ecosystem. However, decaying sewage was harm-
ful to aquatic life even if greatly diluted. The bacter-
ioligical influence of the sewage may be beneficial.
Even though these ponds were not established for sewage
treatment, they are large enough to have sewage intro-
duced into them without detrimental effects. No experi-
mental data concerning the most economical quantity of
sewage purified per given lake area by a given fish
population was obtained. There is, then, an abvious need
for such experimentation to determine these quantitative
figures.
To examine this problem theoretically, one must study the
technical biological aspects of the commercial fisheries.
548
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THE PHYSICAL ASPECTS OF COMMERCIAL FISHERIES
The commercial fisheries are a series of artificial
lakes in which all breeding operations can be carried
out. These operations are: spawning; raising of young;
fish production (for human consumption); feeding and
wintering. The lakes are classified according to the
function they serve, i.e. the spawning lake, breeding
lake and production lake, etc. Continuous sewage clean-
ing can be done in the production lakes, but not in the
fish storage lake because of crowded conditions. The
high dissolved oxygen levels required in the storage
waters can only be obtained by a continuous fresh water
flow or aeration. Introducing sewage into the storage
ponds would only deplete the oxygen supply.
The water level in the breeding lakes is low and the
spawning lakes are operating only intermittently. It is
possible to raise young fish in lakes which have second-
ary, purified, diluted sewage added. The sewage could
increase the plankton population thus increasing the
fingerling's food supply. In an active commercial
fishery the production lakes are most important, the
spawning lakes second.
Different lake types such as mountain lakes (with valley
dams),flatland lakes (with dikes), or intermediate types
are suitable for sewage purification, but the technical
approach will have to differ. Lakes with valley dams
seem to be the most economical because the water supply
can also serve as a diluent. Sewage is purified much
faster flowing through the series of valley lakes. The
nutrient rich effluent fertilizes a number of lakes as
opposed to the single pond method mentioned earlier.
Controlling the size of the fish population in these
lakes is an important operation. Population size is
related to natural food supply. Both are increased with
the introduction of sewage into a lake. The feeding
program (additional feeding) of the fish has to be
adjusted accordingly. To do this one has to know the
level of the natural food supply and the fish yield
obtained without additional feeding. The time of "fish
harvest" will determine how long the sewage can be pumped
into the lake sector and when it can be reintroduced.
Considering the technical and practical aspects of such
fisheries, their success depends on the synchronous
planning and effort of the hydrologist and fishery manager,
549
-------
In ray opinion, a fishery sewage treatment plant not
prepared in this manner is unacceptable since vital con-
ditions will invariably be overlooked, e.g.,pond water
capacity, fish density, harvesting time, periodic drain-
ing and dry draining schedule, and refilling schedules.
Also, these conditions should be fixed and stipulated in
the water rights permit.
BIOLOGICAL POTENTIAL OF COMMERCIAL FISHERIES
When introducing sewage into a body of water, one has to
consider the biological as well as physical conditions
present. The open water, aerobically respiring, popu-
lations (algae, protozoan, plankton and aerobic bacteria)
of production lakes will aerobically decompose the
introduced sewage. As Woynarovich" pointed out, one has
to achieve a rapid mixing of the sewage with the diluent
water or recycled lake water to prevent the sewage's
settling to the bottom. The sewage must remain available
for decomposition by the organisms in the water.
In numerous lakes, methods similar to "agitated bottom"
sewage plant procedures could be used to increase
decomposition. This method involves stirring up the
bottom sediments (mud), bringing the anaerobic organisms
into contact with the effluent thus assisting in its
decomposition.
Water quality is closely related to a lake's biological
potential. In many lakes, especially in western Hungary,
because of eutrophic conditions, the oxygen utilization
is high (10-20 mg/1 and higher). At the same time, blue-
green algaes such as Microcystis. Anabaena and Aohanizo-
menon abound. They store nitrogen and produce oxygen.
There is, under normal conditions, an excess of
dissolved oxygen. In some regions the wind disperses
these masses of organisms vertically or deposits piles
of them on the shores. During calm hot summer days and
according to some during atmospheric changes, these algae
begin dying off. The oxygen balance is upset and within
hours there is a fish kill. The introduction of sewage
obviously enhances the possibility of such occurrences,
therefore we must continually be prepared to avert such
dangers. Research is needed to solve this problem, so
that the optimum productivity of a water, in terms of
sewage treatment and fish production, can be achieved.
Another biological problem is the presence of substances
in the sewage which adversely affect the flavor of the
550
-------
fish or render the fish toxic for consumption. The
presence of flavor spoiling substances can be tolerated
in low concentrations if we produce fish for industrial
uses only. There must, however, be clean water, clearing
sections of the lake where the fish can rid themselves
of the toxic substances.
The above discussion shows that the problem of combining
large scale sewage treatment with commercial fisheries
can be solved. Obviously it has great advantages with
respect to fish-production and waste utilization. I must
re-emphasize that the planning and execution of such a
project is a multifaceted task requiring great foresight.
We have to distinguish between two possibilities:
1. The introduction of sewage into a lake with such
quantities of water that after a short while sewage
can be detected in only a small area. This is not
commercial fishery (fish-pond) sewage treatment,
but simply placement of sewage into a lake.
2. The close association of a sewage treatment
commercial fishery with a sewage treatment plant.
The most efficient and economical treatment of
mechanically cleaned sewage would be decomposition
by the microorganisms in the water. This is a
balanced procedure of fish production and sewage
treatment.
SEWAGE TREATMENT FISHERIES
The sewage treatment potential can be utilized efficiently
only if the fishery is established for the primary
purpose of sewage treatment and fish production secondary.
These two goals must be maintained in harmony with each-
other. An important differentiation here is that the
objective of sewage placement is not solely the fertili-
zation of the fish-pond but the treatment of sewage as
well as its utilization. Although it is possible to
convert a primarily fish producing fishery into a sewage
treatment fishery, as long as certain alterations of the
fishery management and the sewage treatment plant have
not taken place, we face obstacles which will interfere
with either the raising of fish or the treatment of
sewage.
Let me describe a commercial fishery established for
the purpose of sewage treatment. The lake represents
an extension of the sewage plant, the fishery managers
have to adjust to the sewage plant management. Such
557
-------
fisheries consist of a series of ponds some of which can
always accept sewage. The area of the ponds and its
daily and seasonal fluctuations are correlated with the
amount of sewage added daily. This fishery has clearing
sections (as described earlier) where marketable fish are
raised. Fingerlings could also be raised for other
fishery needs. In planning such a fishery the following
points must be considered:
1. The structure of the lake.
2. The structure of the sewage plant.
3. Water supply, sewage supply, sewage conveyance
and sewage distribution.
4. Production plan and continuity of sewage treatment.
5. Supply of fish (fingerlings).
6. Winter operation of harvested (empty) and stocked
lakes.
7. Fish health.
8. Public health aspects.
9» A one-year operational plan, outlined.
What are alternatives to incomplete (seasonal) opera-
tions? In such instances the lakes may be smaller and
the number of lake sections will depend on the following:
1. If no diluent is used particular sections should
receive (evenly spaced) repeated monthly doses of
sewage.
2. If a diluent water is used the sewage input
should be adjusted to a constant ratio with the
water.
Toxic substances in the sewage must be 50^ below their
toxicity level. In the presence of flavor spoiling sub-
stances one should keep the fish in the ponds for only
one season whereupon they are transferred to clean water
and allowed to regain their natural flavor.
The period of sewage input has to be determined experi-
mentally according to lake size, sewage quantity and
552
-------
biological conditions of the water. (The clearing factor
is a value which varies from season to season),
SEWAGE INTRODUCTION INTO COMMERCIAL FISHERIES
The primary purpose of such lakes if fish production.
The purpose of seivage introduction Is fertilization.
The sewage input must be controlled at all times by
diversion into other lakes or disposal systems. One
should also be able to channel the sewage into several
lake sections. Sewage introduction has to cease two
weeks prior to fish harvest (both summer and fall) and
when the lake bed is dry or during disinfection periods.
For our climatic conditions we must establish the lake
area a) before stocking and b) after stocking, required
for the amount of sewage to be pumped in, i.e. the amount
of sewage which can be introduced per unit of lake area,
considering water depth and the season so that ^-mesosa-
probial conditions already exist at the time of stocking.
Furthermore, we have to establish the ratio of sewage to
water to maintain the ^9-mesosaprobial conditions.
One has to equip the lakes with a sewage by-pass and
distribution canal system. The sewage input ducts must
be separated so as to assure even distribution. The
number of inlets should be variable according to sewage
quantity. Even distribution is desirable especially
when no diluent water is used. If sewage concentrate
(sedimented sewage) is used, it is desirable to apply
calcium oxide prior to stocking and after the fish
harvest.
Checking the water quality and saprobic conditions
regularly by chemical and microscopic examinations is
important. This is a part of lake management. If algae
become over abundant the causative agent (compound) has
to be determined and depending on the extent of the
bloom one may have to stop sewage introduction. In
lakes of this type one can raise yearling and two year
old carp and tench and possibly other grazing species.
Experimentation will determine whether other useful
species can be raised.
Fish to be sold for consumption must be kept in clean
water lakes for a month (or at least 2-3 weeks) prior
to harvest. Specific regulations should be established
by the animal health service. Fish may be raised
without compliance to such regulations if they are used
for other purposes, e.g. breeding stock.
553
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EXPERIMENTAL SEWAGE TREATMENT FISHERIES
All our colleagues agree that planning of sewage treat-
ment fisheries will encounter difficulties as long as
experiments cannot be conducted. They are essential in
gaining experience (knowledge). Aside from the above
described tasks we shall summarize the factors which
we have considered in the establishment of an experi-
mental sewage treatment fishery. When choosing the site
we have to consider the sewage plant and fish production
aspect equally. The fishery should consist of a number
of pond sections (series). It is desirable that the
experimental ponds be in a star configuration as at
Szarvas, Hungary. In these 16 small ponds of equal
size the number of possible variations and duplications
is sufficiently large. To obtain dependable results a
minimum of 4 variations in duplicate are required. A
water supply must be available to allow experimentation
with and without diluent.
The experiments have to be oriented to the following
problems:
1. Degree of sewage clearing efficiency with
different dilutions and without dilution.
2. Determination of fish population density at
different levels of sewage concentration.
3. Fish yield without additional feeding.
4. Experiments with additional feeding of different
population levels.
5. Determination of sewage introduction methods.
6. Rate of weight gain (average weight) of
different aged fish when fertilization with
sewage only.
7. Determining how to inhibit the effect of flavor
spoiling substances.
Apart from the experimental operations, one also has
to establish a laboratory where continuous checks on the
microbial and chemical processes of sewage decomposition
and animal and public health examinations can be made.
As a result of the investigations into fishery sewage
treatment many new aspects of this concept have been
554
-------
elucidated. The microbial activity in lakes is now
better understood. Decomposing sewage with algae gained
prominence among biological treatment methods. The
proposed experimental sewage treatment fishery would
make domestic experimentation possible.
SUMMARY
After urgent requests from planning engineers and
fishing specialists, the (governmental) Sewage Branch
put the question of sewage treatment fisheries on its
agenda. The examination of our small natural lakes into
which sewage is introduced has commenced. The planner
has to consider the technical and biological properties
of such fish producing lakes first. We have to distin-
guish between sewage treatment fisheries and the
commercial fisheries into which sewage is introduced.
In the former, the sewage plant and the fishery
constitute a coordinated operation, sewage treatment
being the primary objective and fish breeding the
secondary one. In the latter, fish breeding is the
primary and sewage treatment the secondary objective.
The questions raised can only be solved satisfactorily
through trials conducted in experimental sewage treatment
fisheries. Such experimental operations would also
afford opportunity for needed algae research. The
utilization of algaes in sewage treatment offer great
possibilities.
LITERATURE CITED
1. Balogh, J. 1963. Utilization of wastewaters.
Termeszettudomanyi Kozlony. 7(7):3l6-3l£ and
7(10):461-463.
2. Csanady, M., M. Gregacs, S. Mahunka and A. Lengyel.
No date. 24 hour in depth public health examination
of the Balalon foldvar sewage treatment fisheries.
Egeszsegtudomany. 194(3):145-156
3. Csanady, M., and M. Gregacs. 1964. Examination
of public health questions, regarding sewage
treatment, in fisheries. Hidrologial Kozlony. 2.
4. Donaszy E. 19 5#. Waste water and fishponds.
Halaszat 5(1):2.
5. Imhoff, K. 1951. Handbook of city water system 14.
Auf1. Munchen.
-------
6. Woynarovich, E. 1959. Can the sewage treatment
fishery be established in Hungary? Halaszat, 6(4):64.
556
-------
PART 8 APPENDICES
-------
PROGRAM COMMITTEE
George H. Allen, Ph.D. - Chairman
Professor of Fisheries
School of Natural Resources
California State University, Humboldt
Arcata, California 95521
Richard E. Thomas - Co-chairman
Research Soil Scientist
Robert S. Kerr Water Research Laboratory
Environmental Protection Agency
P.O. Box 1198
Ada, Oklahoma 74820
Leland J. McCabe, M.P.H., B.S.C.E.
Chief, Criteria Development Branch
Water Supply Research Laboratory
National Environmental Research Center
Environmental Protection Agency
Cincinnati, Ohio 45268
Kenneth 0. Allen, Ph.D.
Fisheries Biologist
Fish Farming Experimental Station
Bureau of Sport Fisheries and Wildlife
P.O. Box 860
Stuttgart, Arkansas 72160
John Marsh, P.E.
President, Engineering Enterprises
P.O. Box E
Norman, Oklahoma 73069
557
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LOCAL ARRANGEMENTS COMMITTEE
Charles D. Newton, P.E. - Chairman
Chief, Water Quality Services
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Charles Lawrence, P.E. , Ph.D.
Assoc. Professor of Environ-
mental Health
Univ. of Oklahoma Health
Sciences Center
P.O. Box 26901
R. LeRoy Carpenter, M.D. - Co-chairman Oklahoma City, Oklahoma 73190
Commissioner of Health
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Mark S. Coleman, Director
Water Quality Monitoring and
Research Division
Water Quality Services
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Dave Dougall, M.E.S.
Administrative Assistant
Water Quality Services
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Reginald Frank, Ph.D.
Research Grants Coordinator
Water Quality Service
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Bill Griffith
Associated Milk Producers, Inc.
1700 North Sooner Road
Oklahoma City, Oklahoma 73141
Ron Jarman
Assistant Chief, Management Fish
Division
Oklahoma Dept. of Wildlife
Conservation
1801 Lincoln
Oklahoma City, Oklahoma 73105
Jim Pollard, Supervisor
Environmental Control, Air
and Water
Oklahoma Gas & Electric Co.
P.O. Box 321
Oklahoma City, Oklahoma 73101
Jim Russell
Aquaculture Industry, Inc.
2116 West 24th Avenue
Stillwater, Oklahoma 74074
Lester Settle, P.E.
Settle, Dougall & Spear,
Engineers
Colcord Building
Oklahoma City, Oklahoma 73102
Michael R. Spear, P.E.
Settle, Dougall & Spear,
Engineers
Colcord Building
Oklahoma City, Oklahoma 73102
PUBLICITY
Toni Morrow
Public Information
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
558
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REGISTRANTS
Ronald K. Abe
Associate Professor
Fort Valley State College
FVSC Box 1494
Fort Valley, Georgia 31030
Kenneth 0. Allen, Ph.D.
Fish Farming Experimental Station
Box 860
Stuttgart, Arkansas 72160
Jack Ashman
OEIMC
East Central State College
Ada, Oklahoma 74820
Carl Astley
Graduate Student
School of Environmental Health
641 Northeast 15th
Oklahoma City, Oklahoma 73101
Robert S. Ayers
Soil & Water Specialist
Agriculture Extension
University of California
Davis, California 95616
Dr. Dan Badger
Professor
Agricultural Economics
Oklahoma State University
Stillwater, Oklahoma 74074
Bill Bailey
Game & Fish Biologist III
Arkansas Game & Fish Commission
P.O. Box 178
Lonoke, Arkansas 72086
John M. Baker
Asst. Head, Civil Engineering
Benham-Blair
6323 N. Grand Blvd.
Oklahoma City, Oklahoma 73118
James V. Basilico
Chief, Process Development
Branch
Environmental Protection Agency
3702 D. WSM
Washington, D.C. 20460
Robert K. Bastian
Resident EPA Rep.
U.S. Environmental Protection
Agency
P.O. Bldg. - 268 Market Street
Muskegon, Michigan 49440
John W. Baxter
Assistant Engineer
Water Quality Service
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Herbert Beauchamp
Supervisor, Virology Section
Oklahoma State Dept. of Health
P.O. Box 53551
Oklahoma City, Oklahoma 73105
Thomas E. Berry
Box 528
Stillwater, Oklahoma 74074
E. E. Blanchard
Civil Engineer
Oklahoma Gas & Electric Co.
P.O. Box 321
Oklahoma City, Oklahoma 73101
Fred C. Boswell
Professor, Agron - Soils Res.
University of Georgia
Georgia Station
Experiment, Georgia 30212
559
-------
W. V. Bowennan
Product Development Engineer
Manitoba Government
Dept. of Industry & Commerce
210 - 185 Carlton
Winnipeg, Manitoba, Canada R3C-1P3
David Bowman
Department of Zoology
Oklahoma State University
Stillwater, Oklahoma 74074
Homer Buck
Aquatic Biologist
Illinois National Historical Survey
R.R. #1
Kinmundy, Illinois 62854
Dr. Robert L. Bunch
Chief, Treat. Proc. Div. Branch
AWTRI, Environmental Protection
Agency
NERC 4676 Columbia Parkway
Cincinnati, Ohio 45268
Donald R. Bunn
Assistant City Engineer
City of Fayetteville
P.O. Box "F"
Fayetteville, Arkansas 72701
Nathan C. Burbank, Jr., Sc.D.
Prof, of Environmental Health &
Sanitary Engineering
School of Public Health
University of Hawaii
1960 East-West Road
Honolulu, Hawaii 96822
Krisen Euros
Research Engineer
Black, Crow & Eidsness
P.O. Box 7133
Christiansted, U.S. Virgin Is,
Allen Butchbaker
Ag. Engineering Dept.
Oklahoma State University
Stillwater, Oklahoma 74074
Charles P. Carlson
Fishery Biologist
Bureau of Sport Fisheries
& Wildlife
Box 292
Stuttgart, Arkansas 72160
Clarence A. Carlson
Assoc. Prof, of Fishery Biology
Colorado State University
301 Aylesworth Hall
Fort Collins, Colorado 80521
John W. Carter, Sr.
Dir. of Res. Protection & Dev.
Grand River Dam Authority
P.O. Drawer G
Vinita, Oklahoma 74301
Preston E. Carter
Chief of Water Pollution Sec.
Oklahoma City-County Health
Department
921 N.E. 23rd Street
Oklahoma City, Oklahoma 73105
Jim Carver
City Engineer
City of Duncan - Box 969
Duncan, Oklahoma 73533
H. A. Caves
Sanitarian
Garvin County Health Dept.
Box 695
Pauls Valley, Oklahoma 73075
Harry Chichester, Dom. Insp. I
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Lester J. Clarke
00820 Consulting Engineer
316 Wildewood Terrace
Oklahoma City, Oklahoma 73105
560
-------
Jeannette Cook
OEIMC
East Central State College
Ada, Oklahoma 74820
Dr. Berniece N. Crockett
Research - Education
Oklahoma Water, Inc.
625 Fidelity Plaza
Oklahoma City, Oklahoma 73102
Robert E. Cullen
Engineer
Dept. of Pollution Control
Box 53504
Oklahoma City, Oklahoma 73105
Dr. Dudley D. Culley, Jr.
Associate Professor
Louisiana State University
249 Ag. Center
Baton Rouge, Louisiana 70803
Dr. Runyan Deere
State Health Education Leader
Arkansas Cooperative Extension
Service
P.O. Box 391
Little Rock, Arkansas 72203
Robert Delano
Assistant Chemist
Oklahoma State Department of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Don Denton, Lab Supervisor
South Okla. City Jr. College
7777 South May Avenue
Oklahoma City, Oklahoma 73135
William G. Dodd
Industrial Specialist
Southeastern State College
Durant, Oklahoma 74701
William R. Duffer, Ph.D.
Research Aquatic Biologist
Environmental Protection Agency
Box 1198
Ada, Oklahoma 74820
Ray Duffy
Utility Superintendent
City of Frederick
P.O. Box 399
Frederick, Oklahoma 73542
Judy Duncan
Sanitarian
Water Quality Service
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Mike L. Packer
Graduate Student
Oklahoma State University
2422 S. Hudson Place
Tulsa, Oklahoma 74114
Dwain Farley
Environmental Program Spec. 1
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
John Feddes
Agricultural Engineer
Pollution Control Branch
Parliament Buildings
Victoria, British Columbia
Canada
Stephen A. Flickinger
Assistant Professor
Dept. of Fishery & Wildlife
Biology
Colorado State University
Fort Collins, Colorado 80521
567
-------
Ted H. Forester
Sanitary Engineer III
Missouri Clean Water Commission
Box 154
Jefferson City, Missouri 65101
Pedrito A. Francois
Director, Environmental Health
Virgin Islands Health Dept.
Box 543
Charlotte Amalie, Virgin Islands
Reginald H. Frank. Ph.D.
Research Grants Coordinator
Water Quality Service
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Dr. B. A. Friedman
Union Carbide Corporation
Linde Division
Box 44
Tonawanda, New York 14150
Westal W. Fuchs (Fox)
State Soil Scientist
Soil Conservation Service
Farm Road & Brumley
Stillwater, Oklahoma 74074
Everett Gartrell
Mayor
City of Weatherford
P.O. Box 133
Weatherford, Oklahoma 73096
Glen Gebhard
Department of Zoology
Oklahoma State University
Stillwater, Oklahoma 74074
Bernie Gipson
Chemist
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Harry Hansen
Environmental Manager
U.S. Pollution Control, Inc.
2000 Classen Center
Suite 200 South
Oklahoma City, Oklahoma 73106
Eldon T. Head
City Manager
City of Duncan
00801 Box 969
Duncan, Oklahoma 73533
Elliott S. Hechtman
President, Aquarium Farms, Inc.
Box 1015
Fremont, Nebraska 68025
Phil Henderson
Biologist
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Scott Henderson
Joe Hogan State Fish Hatchery
Arkansas Game & Fish Commission
P.O. Box 178
Lonoke, Arkansas 72086
Jim Holland
Assn. of S. Central Okla. Govts.
802 Main Street
Duncan, Oklahoma 73533
Dr. Charles C. Hortenstine
Associate Professor
Soil Science Dept.
University of Florida
106 Newell Hall
Gainesville, Florida 32611
David G. Hughes
Warm Water Fish Culturist
Zoology Department
Oklahoma State University
Stillwater, Oklahoma 74074
552
-------
Andrew H. Hulsey
Joe Hogan State Fish Hatchery
P.O. Box 178
Lonoke, Arkansas 72086
E. E. "Gene" Humes
Sanitary Engineer
Williams Bros. Waste Control, Inc.
321 S. Boston
Tulsa, Oklahoma 74103
James V. Rusted
Graduate Assistant
Penn State University
108 Ag. Engineering
University Park, Pa. 16802
Brad Jackson
Biologist II
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Lee W. Jacobs
Assistant Professor
Dept. of Crop & Soil Sciences
Michigan State University
East Lansing, Michigan 48824
Col. Howard R. Jarrell, Assoc. Dir.
Okla. Water Resources Research Inst.
Oklahoma State University
Stillwater, Oklahoma 74074
Lawrence M. Jones
Environmental Engineer
Western Electric
7725 West Reno
Oklahoma City, Oklahoma 73125
Timothy Joyner
Manager, Aquaculture Program
Northwest Fisheries Center
2725 Montlake Blvd. E
Seattle, Washington 98112
C. H. Lawrence, P.E., Ph.D.
Assoc. Professor of Environ-
mental Health
Univ. of Okla. Health Sciences
Center
641 Northeast 15th Street
Oklahoma City, Oklahoma 73105
Patterson Lay
Oklahoma City Public Works Dept.
200 North Walker
Oklahoma City, Oklahoma 73102
Ronald D. Lees
Research Engineer
Hercules Incorporated
900 Green Bank Road
Wilmington, Delaware 19809
Erne Lewis
Architect
Kramer, Chin & Mayo
1917 First Avenue
Seattle, Washington 98101
Dr. Ronald F. Lewis
Research Microbiologist
Environmental Protection Agency
Robert A. Taft Laboratory
4676 Columbia Parkway
Cincinnati, Ohio 45226
Harold Loyacano
Asst. Professor Zoology
Clemson University
Ent. & Econ., Zoology
Clemson, South Carolina 29631
Robert A. Mah
Assoc. Professor Public Health
U.C.L.A.
School of Public Health
Los Angles, California 90024
Harold K. Malone
Asst. Chief, Laboratory Services
Oklahoma State Dept. of Health
Box 53551
Oklahoma City, Oklahoma 73105
563
-------
Harry Manges
Associate Professor
Agricultural Engineering
Kansas State University
Manhattan, Kansas 66506
John Marsh
Engineering Enterprises
P.O. Box E
Norman, Oklahoma 73069
Leland J. McCabe, Chief
Criteria Development Branch
Water Supply Research Laboratory
Environmental Protection Agency
Cincinnati, Ohio 45268
Donald L. Mehlburger, President
Mehlburger Engineers, Inc.
1218 W. 3rd Street
Little Rock, Arkansas 72201
James W. Merna
Fisheries Research Biologist
Mich. Dept. of Natural Resources
Inst. for Fisheries Research
Museums Annex
Ann Arbor, Michigan 48104
Dennis Messmer, Ph.D.
Assoc. Professor Micro.
Southwestern State College
Dept. of Biological Sciences
Weatherford, Oklahoma 73096
Ray A. Mill
Planner
Oklahoma Dept. of Pollution Control
Box 53504
Oklahoma City, Oklahoma 73105
Aaron Mitchum
Microbiologist II, Diag. Bact.
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Bill Moyer
Program Director
Oklahoma Municipal League
4040 Lincoln Boulevard
Oklahoma City, Oklahoma 73105
Charles D. Newton
Chief, Water Quality Services
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
John G. Nickum
Assistant Leader
U.S. Dept. of Interior
Fish and Wildlife Service
Bureau of Sport Fisheries &
Wildlife
New York Cooperative Fishery
Unit
Cornell University
Ithaca, New York 14850
W. Harold Ornes
Biologist
University of Florida
IFAS Exp. Sta. Res. Center
3205 S.W. 70th Avenue
Fort Lauderdale, Fla. 33314
Mario M. Pamatmat
Associate Professor
Auburn University
Dept. of Fisheries & Allied
Aquacultures
School of Agriculture &
Aquaculture
Experiment Station System
Auburn, Alabama 36830
Lloyd Parham, Director
Milk & Interstate Carrier Div.
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
564
-------
John T. Patton
Prof, of Chemical Engineering
Michigan Tech. University
Houghton, Michigan 49931
Dr. Thomas D. Peace
Director
Okla. Dept. of Pollution Control
Box 53504
Oklahoma City, Oklahoma 73105
Howard S. Peavy
Chief Engineer
Okla. Dept. of Pollution Control
Northeast Tenth and Stonewall
Box 53504
Oklahoma City, Oklahoma 73105
Ron Peterson
Planning Engineer
Okla. Dept. of Pollution Control
Box 53504
Oklahoma City, Oklahoma 73105
Jim Pollard, Supervisor
Environmental Control, Air and Water
Oklahoma Gas & Electric Company
321 North Harvey
P.O. Box 321
Oklahoma City, Oklahoma 73101
Loyd F. Pummill, Deputy Com. for
Environmental Health Services
Oklahoma State Dept. of Health
Northeast Tenth & Stonewall
Oklahoma City, Oklahoma 73105
Robert E. Reid
Councilman, Town of Brookhaven
Brookhaven National Laboratory
Upton, New York 11973
Marcel C. Reynolds
Staff Member
Sandia Laboratories
Albuquerque, New Mexico 87115
Clifford Risley, Jr.
Director, Research and
Development
U.S. Environmental Protection
Agency
1 North Wacker Drive
Chicago, Illinois 60606
Dr. James M. Robertson
Associate Professor
University of Oklahoma
202 West Boyd
Norman, Oklahoma 73069
H. Randall Robinette
Asst. Professor
Mississippi State University
P.O. Drawer LW
Mississippi State, Miss. 39762
Mickey Rowe
OEIMC
East Central State College
Ada, Oklahoma 74820
Ara Roy
Microbiologist IV
Supervisor, Sanitary Bacterio-
logy
Oklahoma State Dept. of Health
Box 53551
Oklahoma City, Oklahoma 73105
Jim Russell
2116 West 24th Avenue
Stillwater, Oklahoma 74074
Patrick J. Ryan
Chief, Environmental Affairs
Oklahoma Gas & Electric Co.
321 North Harvey
P.O. Box 321
Oklahoma City, Oklahoma 73101
565
-------
William R. Schtnieding, Ph.D.
Chief, Laboratory Services
Oklahoma State Dept. of Health
Box 53551
Oklahoma City, Oklahoma 73105
Delbert Schwab
Ext. Irrigation Spec.
Oklahoma State University
Room 216 - Ag. Hall
Stillwater, Oklahoma 74074
Kenneth R. Settle
Sanitarian I
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Lester L. Settle
Settle, Dougall & Spear, Engineers
Colcord Building
Oklahoma City, Oklahoma 73105
Manse R. Sharp, Jr.
Banyon Engineering & Management Co.
1315 East First National Center
Oklahoma City, Oklahoma 73102
Thomas R. Sharp
Graduate Student - Fisheries
Humboldt State University
Box 51 WRS
Trinidad, California 95570
W. W. Shepherd
Chemist
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Kenneth Shirley
Department of Zoology
Oklahoma State University
Stillwater, Oklahoma 74074
Dewey L. Shroyer
Director, Grounds Maintenance
Dept.
Texas Tech. University
Box 4169
Lubbock, Texas 79409
Max Slifer
Watersaver Company, Inc.
P.O. Box 16465
Denver, Colorado 80216
Maxwell M. Small
Special Projects Manager
Brookhaven National Laboratory
Building 318
Upton, New York 11973
K. E. Sorrells, Chief Chemist
Arkansas Dept. of Pollution
Control
8001 National Drive
Little Rock, Arkansas 72209
Richard D. Spall
Asst. Professor
College of Veterinary Medicine
Oklahoma State University
Stillwater, Oklahoma 74074
Michael R. Spear
Settle, Dougall & Spear,
Engineers
Colcord Building
Oklahoma City, Oklahoma 73102
John Spine Hi
Research Chemist
National Marine Fishery Service
2725 Montlake Bldg. E
Seattle, Washington 98112
Dr. Robert C. Summerfelt
Department of Zoology
Oklahoma State University
Stillwater, Oklahoma 74074
566
-------
David L. Sutton, Ph.D.
Agronomist
University of Florida
IFAS, Exp. Sta. Res. Center
3205 S.W. 70th Avenue
Fort Lauderdale, Florida 33314
Benny F. Swafford
Hydraulic Engineer
U.S. Corps of Engineers
Forrestal Building
Washington, D.C. 20314
Tom Switalski
Sales Engineer
Certain-Teed Products
Pipe & Plastics Group
Box 86D
Valley Forge, Pa. 19482
Dr. Denver Talley
Assistant Director
Department of Pollution Control
Box 53504
Oklahoma City, Oklahoma 73105
Howard A. Tanner
Professor and Director
Michigan State University
109 National Resources Bldg.
East Lansing, Michigan 48824
Richard E. Thomas
Research Soil Scientist
Environmental Protection Agency
Box 1198
Ada, Oklahoma 74820
Larry H. Thompson
Assistant Director
Okla. Economic Development Assn.
Box 668
Beaver, Oklahoma 73932
Dr. Gary H. Toenniessen
Asst. Director, National &
Environmental Science
Rockefeller Foundation
111 West 50th Street
New York, New York 10020
Ronald L. Thune
Graduate Student
Western Illinois University
Dept. of Biology
Macomb, Illinois 61455
Dr. Thomas C. Tucker
Water Resources Research Center
University of Arizona
Tucson, Arizona 85721
Dr. James M. Vaughn
Virologist
Woods Hole Oceanographic Inst.
Department of Biology
Woods Hole, Massachusetts 02543
W. Frank Wade
Associate Professor
Southeastern State College
Biology Department
Durant, Oklahoma 74701
George R. Waller
President & Managing Director
Midcontinent Environmental
Center Association
Box 201
Tulsa, Oklahoma 74102
G. W. Wallingford
Dept. of Agronomy
Kansas State University
Waters Hall
Manhattan, Kansas 66506
Jack N. Walter
Graduate Assistant
Penn State University
233 Ag. Engineering
University Park, Pa. 16802
557
-------
Charles W. Ware, Engineer
Assn. of So. Central Okla. Govts.
802 Main Street
Duncan, Oklahoma 73533
Thomas P. Wasbotten
Sanitary Engineer
Mich. Dept. of Natural Resources
Municipal Wastewater Division
120 Maplewood Drive
East Lansing, Michigan 48823
William R. Whiting
President
Sea Ranch, Inc.
Route 2, Box 604
Sheridan, Arkansas 72150
David Wilds
Fish Fanner
Wilds Fish Farm
Route 2, Box 55
Yukon, Oklahoma 73099
George Wilkinson
Administrator
City of Weatherford
Box 569
Weatherford, Oklahoma 73096
Ted A. Williamson
Senior Engineer
Oklahoma State Dept. of Health
Northeast Tenth and Stonewall
Oklahoma City, Oklahoma 73105
Gary Wolgamott, Ph.D.
Assoc. Professor Micro.
Southwestern State College
Department of Biological Sciences
Weatherford, Oklahoma 73096
Kenneth J. Ziegler
Civil Engineer
Missouri Clean Water Commission
Box 154
Jefferson City, Missouri 65101
«U£. GOVEKNUaUT MINTING OFFICE:1974 546-319/429 1-3
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
A ccessioa JVo.
W
4. Title
WASTEWATER USE IN THE PRODUCTION OF FOOD
AND FIBER—PROCEEDINGS,
7. AuthoT(s)
9. Organization
Robert S. Kerr Environmental Research Laboratory
P. O. Box 1198
Ada, Oklahoma 74820
5.
8,
,-ferttu ,j Org& .-satfott
So.
10. Ptoject No.
11. Contract/Grant No.
Type f Repo. - and
Period Covered
12. Sr-nsoric -Organ' itioa
IS. Supplementary Notes
Environmental Protection Agency Report No. EPA-660/2-74-041, June 19TU
16. Abstract
An interdisciplinary group of about 200 persons met to review the present base of
scientific knowledge relating to benefits and constraints of using wastewaters for
production of food and fiber. There were 27 papers presented by representatives
from the fields of public health, engineering, agriculture, aquaculture, and other
related scientific disciplines. Papers in two sections on potential restraints cover
topics such as historical instances of disease transmission, possible transport of
microbial pathogens through the food chain, legal implications, and sociological
reactions. The aquaculture section deals primarily with experimental studies
including such diverse approaches as culture ofdaphnia, salmon smoits, and
water hyacinth. The agriculture section emphasizes the use of wastewater for
crop production and the papers presented include case histories for long-term
operating systems, as well as data from experimental studies. In addition to those
papers presented at the conference, nine others have been included to make a
total of 36 papers in the conference proceedings.
na. Descriptors
* Aquaculture, *lrrigation practices, *Wastewater treatment, *Crop production,
Conferences, Research facilities, Thermal water, Daphnia, Catfishes, Forage
grasses. Fiber crops. Trees, Salmon, Public health. Water law. Water hyacinth.
17b. Identifiers
*Fish culture, * Aquatic plant culture.
17c. CO WRR Field & Group Q3C, 05D, 06E
IS. A variability
19. Security Class.
.'Repc, )
'0. Sei 'fityCl js.
(Page)
21.
Ho. of
Pages
Pri-.a
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 2O24O
Abstractor K. E.
I institution Robt. S. Kerr Environ Research Lab.
\VRS3C 1O2 (REV JUNE I97O
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