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800R68900
Water Quality Criteria
Report of the
National Technical Advisory Committee
to the
Secretary of the Interior
APRIL 1, 1968
WASHINGTON, D.C.
FEDERAL WATER POLLUTION CONTROL ADMINISTRATION
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For sale by the Superintendent of Documents, U. S. Government Printing Office
Washington, D.C., 20402—Price $3.00
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LETTER OF TRANSMITTAL
Hon. Stewart L. Udall, Secretary
U.S. Department of the Interior
This letter transmits the report of the National Technical Advisory Com-
mittee on Water Quality Criteria. The chairmen of the five Subcommittees are to
be commended for an excellent job in pulling together a mass of information and
coordinating the efforts of the members to complete the report by the requested
date of June 30, 1968.
This volume constitutes the most comprehensive document on water quality
requirements to date, and as such, will be used as a basic reference by groups and
agencies engaged in water quality studies and standards setting activities. At the
same time, the Committee members and I wish to emphasize that this report is not
sufficiently conclusive or inclusive to serve as the only guide in determining water
quality criteria or requirements. Regional variations in climate, topography,
hvdrology, geology, and other factors must be considered in applying the criteria
offered by the Committee to the establishment of water quality standards in specific
localities.
I would also like to note that the Committee members have occasionally
departed from the task of developing water quality criteria, with which you charged
them, to make recommendations which are more properly the province of regulatory
agency policy makers or designers of pollution abatement facilities. A few examples
are:
1. A recommendation that all waters, except those adjacent to waste outfalls,
provide for the maintenance and production of fish.
2- Recommendations of engineering design criteria for waste treatment plants.
3. A recommendation that incineration replace ocean disposal of sludge solids.
The tendency to consider broad issues of policy and design criteria was per-
haps inevitable. While the mission was directed at water quality requirements, it was
easy for the experts to wander and propose approaches that attempt to account for
uncertainties and disagreements concerning scientific criteria. It is to the great credit
of the chairmen that they were able to properly maintain primary attention on water
quality criteria rather than the other two major components of water quality stand-
ards—water use designations and implementation and enforcement plans.
This report is as valuable for what it does not say as for what it does say. The
work of the Committee illuminates the fact that the unknowns still far exceed the
knowns in water quality requirements—even to the experts. Therefore, requirements
should be applied with the best of judgments. One of the most valuable aspects of
the Committee's work was the examination of research needs and the guidance
offered in such needs. A report of research needs is published as a separate docu-
ment.
The FWPCA is grateful to the many participating organizations and individuals
who comprised the Committee. They are to be congratulated for their cooperation
and enthusiasm in this monumental task.
JOE G. MOORE, JR.
Commissioner
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Subcommittee for recreation and
aesthetics
committee
membership
MR. R. FRANK GREGG, Chairman, New England
River Basins Commission, Boston, Mass.
DR. LEONARD DUH.L, Special Assistant to the Sec-
retary of Housing and Urban Development,
Washington, D.C.
MR. CLARENCE W. KLASSEN, Chief Sanitary En-
gineer, Illinois Department of Public Health,
Springfield, 111.
MR. WILLIAM J. LUCAS, Assistant Director, Divi-
sion of Recreation, National Forest System, For-
est Service, U.S. Department of Agriculture,
Washington, D.C.
MR. LELAND J. McCABE, Assistant Program Chief
for Disease Studies and Basic Data, Water Sup-
ply and Sea Resources Program, Public Health
Service, U.S. Department of Health, Education,
and Welfare, Cincinnati, Ohio.
MR. JOHN C. MERRELL, JR., Chief, Southern Cali-
fornia Field Station, Federal Water Pollution
Control Administration, U.S. Department of the
Interior, Garden Grove, Calif.
MR. ERIC W. MOOD, Assistant Professor of Public
Health, Chief, Environmental Health Section,
Department of Epidemiology and Public Health,
Yale University School of Medicine, New
Haven, Conn.
MR. HAROLD ROMER, Director, Department of Air
Pollution Control, City of New York, and Pro-
fessor of Environmental Pollution Control, Long
Island University, Brooklyn,' N.Y.
MR. ROY K. WOOD, Chief, Division of Water Re-
sources Studies, Bureau of Outdoor Recreation,
U.S. Department of the Interior, Washington,
D.C.
DR. RICHARD T. GREGG, Technical Executive Sec-
retary, Federal Water Pollution Control Admin-
istration, U.S. Department of the Interior,
Washington, D.C.
Subcommittee for public water supplies
DR. RICHARD L. WOODWARD, Chairman, Camp,
Dresser and McKee, Boston, Mass.
MR. ELWOOD L. BEAN, Chief, Treatment Section,
Water Department, Philadelphia, Pa.
MR. BYRON BEATTIE, Division of Watershed Man-
agement, Forest Service, U.S. Department of
Agriculture, Arlington, Va.
MR. ROBERT J. BECKER, Superintendent of Purifi-
cation, Indianapolis Water Co., Indianapolis,
Ind.
11
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MR. WILLIAM E. BUDD, Director, Environmental
Systems, Dorr-Oliver Inc., Stamford, Conn.
MR. H. H. GERSTEIN, Consultant, Alvard, Bur-
dick, and Hawson, Chicago, 111.
MR. PAUL D. HANEY, Partner, Black and Veatch,
Consulting Engineers, Kansas City, Mo.
MR. HERBERT O. HARTUNG, Executive Vice Presi-
dent, St. Louis County Water Co., University
City, Mo.
DR. PAUL W. KABLER, Deputy Director, National
Center for Urban and Industrial Health, Public
Health Service, U.S. Department of Health, Ed-
ucation, and Welfare, Cincinnati, Ohio.
MR. KENNETH MACKENTHUN, Federal Water Pol-
lution Control Administration, U.S. Department
of the Interior, Cincinnati, Ohio.
MR. HENRY J. ONGERTH, Assistant Chief, Bureau
of Sanitary Engineering, California State De-
partment of Public Health, Berkeley, Calif.
MR. GORDON G. ROBECK, Director, Water Supply
Research Laboratory, Public Health Service,
U.S. Department of Health, Education, and
Welfare, Cincinnati, Ohio.
MR. HERBERT A. SWENSON, Research Hydrolo-
gist, Geological Survey, U.S. Department of the
Interior, Washington, D.C.
MR. FLOYD B. TAYLOR, Regional Program Chief,
Water Supply and Sea Resources Program,
Public Health Service, U.S. Department of
Health, Education, and Welfare, Boston, Mass.
DR. HAROLD W. WOLF, Technical Executive Sec-
retary, Public Health Service, U.S. Department
of Health, Education, and Welfare, Garden
Grove, Calif.
Subcommittee for fish,
other aquatic life, and wildlife
DR. CLARENCE M. TARZWELL, Chairman, Direc-
tor, National Marine Water Quality Laboratory,
Federal Water Pollution Control Administra-
tion, U.S. Department of the Interior, West
Kingston, R.I.
MR. VYTAUTAS ADOMAITIS, Research Chemist,
Bureau of Sport Fisheries and Wildlife, North
Prairie Wildlife Research Center, U.S. Depart-
ment of the Interior, Jamestown, N.Dak.
DR. BERTIL G. ANDERSON, Professor of Zoology,
Life Sciences Building, The Pennsylvania State
University, University Park, Pa.
MR. GEORGE E. BURDICK, Supervising Aquatic
Biologist (Pollution Research), New York Con-
servation Department, State Campus, Albany,
N.Y.
DR. PHILIP A. BUTLER, Laboratory Director, Bu-
reau of Commercial Fisheries Biological Labo-
ratory, U.S. Department of the Interior, Gulf
Breeze, Fla.
DR. ROBERT J. CONOVER, Atlantic Oceanographic
Group, Fisheries Research Board of Canada,
Dartmouth, Nova Scotia.
DR. OLIVER B. COPE, Director, Fish-Pesticide Re-
search Laboratory, Bureau of Sport Fisheries
and Wildlife, U.S. Department of the Interior,
Columbia, Mo.
DR. RICHARD F. FOSTER, Manager, Earth Sciences
Section, Environmental and Radiological Sci-
ences Department, Pacific Northwest Labo-
ratory, Battelle Memorial Institute, Richland,
Wash.
DR. F. E. J. FRY, Professor of Zoology, Depart-
ment of Zoology, University of Toronto, To-
ronto, Ontario, Canada.
DR. PAUL S. GALTSOFF, Consultant, Woods Hole,
Mass.
DR. ARDEN R. GAUFIN, Professor of Zoology, De-
partment of Zoology and Entomology, Univer-
sity of Utah, Salt Lake City, Utah.
MR. WILLIAM F. GUSEY, Assistant Chief, Division
of Wildlife Services, Bureau of Sport Fisheries
and Wildlife, U.S. Department of the Interior,
Washington, D.C.
DR. WILLIAM J. HARGIS, JR., Director, Virginia In-
stitute of Marine Science, College of William
and Mary and University of Virginia, Glou-
cester Point, Va.
MR. EUGENE P. HAYDU, Water Resources and
Management, Weyerhaeuser Co., Pulp and
Paperboard Division, Longview, Wash.
MR. CROSSWELL HENDERSON, Fishery Biologist,
Bureau of Sport Fisheries and Wildlife, U.S. De-
partment of the Interior, Colorado State Uni-
versity, Fort Collins, Colo.
MR. EUGENE T. JENSEN, Chief, Office of Estuarine
Studies, Federal Water Pollution Control Ad-
ministration, U.S. Department of the Interior,
Washington, D.C.
DR. J. M. LAWRENCE, Auburn University, Au-
burn, Ala.
DR. VICTOR L. LOOSANOFF, Professor of Marine
Biology, Marine Biological Laboratory, Uni-
versity of the Pacific, Dillon Beach, Calif.
DR. DONALD I. MOUNT, National Water Quality
Laboratory, Federal Water Pollution Control
Administration, Department of the Interior,
Duluth, Minn.
DR. RUTH PATRICK, Curator and Chairman of the
Limnology Department, Academy of Natural
Sciences of Philadelphia, Philadelphia, Pa.
ill
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DR. BENJAMIN H. PRINGLE, Supervisory Chemist,
Northeast Marine Health Sciences Laboratory,
Public Health Service, U.S. Department of
Health, Education, and Welfare, Narragansett,
R.I.
DR. D. I. RASMUSSEN, Director, Division of Wild-
life Management, Forest Service, U.S. Depart-
ment of Agriculture, Washington, D.C.
DR. THEODORE R. RICE, Director, Radiobiological
Laboratory, Bureau of Commercial Fisheries,
U.S. Department of the Interior, Beaufort, N.C.
MR. JOHN L. SINCOCK, Chief, Section of Wetland
Ecology, Patuxent Wildlife Research Center,
Bureau of Sport Fisheries and Wildlife, Laurel,
Md.
DR. WILLIAM A. SPOOR, Professor of Zoology, De-
partment of Biological Sciences, University of
Cincinnati, Cincinnati, Ohio.
MR. EUGENE W. SURBER, Commission of Game
and Inland Fisheries, Browntown, Va.
MR. WILLIAM E. WEBB, Water Quality Biologist,
Idaho Fish and Game Department, Boise,
Idaho.
MR. ARTHUR N. WOODALL, Assistant Chief, Divi-
sion of Fishery Research, Bureau of Sport Fish-
eries and Wildlife, U.S. Department of the In-
terior, Washington, D.C.
DR. HAROLD BERKSON, Technical Executive Secre-
tary, Federal Water Pollution Control Adminis-
tration, U.S. Department of the Interior, Wash-
ington, D.C.
Subcommittee for agricultural uses
DR. JESSE LUNIN, Chairman, Chief Soil Chem-
ist, Soil and Water Conservation Research
Division, Agricultural Research Service, U.S.
Department of Agriculture, Beltsville, Md.
DR. LYLE T. ALEXANDER, Chief, Soil Survey
Laboratories, Soil Conservation Service, U.S.
Department of Agriculture, Beltsville, Md.
DR. HENRY V. ATHERTON, Professor, Associate in
Dairy Bacteriology, Animal and Dairy Science
Department, College of Agriculture and Home
Economics, The University of Vermont, Bur-
lington, Vt.
DR. JEPTHA E. CAMPBELL, Chief, Food Chemistry
Unit, Milk and Food Research, Environmental
Sanitation Program, Public Health Service, U.S.
Department of Health, Education, and Welfare,
Cincinnati, Ohio.
DR. EDWIN A. CROSBY, Director, Agriculture Divi-
sion, National Canners Association, Washing-
ton, D.C.
DR. STUART G. DUNLOP, Professor of Microbi-
ology, University of Colorado Medical Center,
Denver, Colo.
DR. HENRY FISCHBACH, Director, Division of
Food Chemistry, Bureau of Science, Food and
Drug Administration, U.S. Department of
Health, Education, and Welfare, Washington,
D.C.
DR. MAURICE N. LANGLEY, Chief, Division of Ir-
rigation and Land Use, Bureau of Reclamation,
U.S. Department of the Interior, Washington,
D.C.
DR. JAMES E. OLDFIELD, Professor and Head, De-
partment of Animal Science, Oregon State Uni-
versity, Corvallis, Oreg.
DR. DEAN F. PETERSON, Dean, College of Engi-
neering, Utah State University, Logan, Utah.
MR. ARTHUR F. PILLSBURY, Professor of Engi-
neering, UCLA, Acting Director, Water Re-
sources Center, University of California, Los
Angeles, Calif.
DR. ARNOLD E. SCHAEFER, Head, Nutrition Sec-
tion, Office of International Research, National
Institutes of Health, U.S. Department of Health,
Education, and Welfare, Bethesda, Md.
MR. JOHN J. VANDERTULIP, Chief Engineer, Texas
Water Development Board, Austin, Tex.
DR. GLENN B. VAN NESS, Assistant Senior Staff
Veterinarian, Technical Services, Animal Health
Division, Agricultural Research Service, U.S.
Department of Agriculture, Beltsville, Md.
MR. C. E. VEIRS, Deputy Director, Columbia
River Basin Project, Federal Water Pollution
Control Administration, U.S. Department of the
Interior, Portland, Oreg.
MR. HURLON C. RAY, Technical Executive Secre-
tary, Federal Water Pollution Control Admin-
istration, U.S. Department of the Interior,
Washington, D.C.
Subcommittee for
industrial water supplies
MR. JAMES K. RICE, Chairman, Cyrus W. Rice &
Co., Pittsburgh, Pa.
MR. W. A. BURHOUSE, Assistant Director, Com-
mittee for Air and Water Conservation, Ameri-
can Petroleum Institute, New York, N.Y.
MR. S. R. COOPER, Director of Pollution Abate-
ment, Oxford Paper Co., Rumford, Maine.
MR. BRUCE W. DICKERSON, Manager, Sanitary
Engineering, Hercules Inc., Wilmington, Del.
DR. ROBERT S. INGOLS, Research Professor of Ap-
IV
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plied Biology, Engineering Experiment Station,
Georgia Institute of Technology, Atlanta, Ga.
MR. EARL R. ROLLER, Water Resources Engineer,
Portland Cement Association, General Office,
Chicago, 111.
MR. S. KENNETH LOVE, Chief, Quality of Water
Branch, Geological Survey, U.S. Department of
the Interior, Washington, D.C.
MR. FRANK W. MELCHER, Head of Water Re-
search Section, Research and Development De-
partment-Carbonated Beverages, Technical Di-
vision, The Coca-Cola Co., Atlanta, Ga.
MR. WALTER A. MERCER, Associate Director, Na-
tional Canners Association Research Labora-
tories, Western Research Laboratory, Berkeley,
Calif.
DR. EVERETT P. PARTRIDGE, Consultant, Beaver,
Pa.
MR. SHEPPARD T. POWELL, Sheppard T. Powell
and Associates, Baltimore, Md.
PROFESSOR WILLIAM T. RODDY, Tanner's Council
Laboratory, University of Cincinnati, Cincin-
nati, Ohio.
MR. Louis W. ROZNOY, Manager, Effluent Con-
trol, Chemicals Division, Olin Mathieson
Chemical Corp., Stamford, Conn.
DR. WILLIAM R. SAMPLES, Fellow and Acting
Head, Water Resources, Mellon Institute, Pitts-
burgh, Pa.
MR. JOSEPH W. STRUB, Senior Water Consultant,
E. I. du Pont de Nemours & Co., Inc., Engineer-
ing Department, Engineering Service Division,
Wilmington, Del.
DR. SIDNEY SUSSMAN, Vice President-Technical
Director, Water Service Laboratories, Inc., New
York, N.Y.
MR. DEYARMAN WALLACE, Research Supervisor,
The Youngs town Sheet & Tube Co., Youngs-
town, Ohio.
DR. LLOYD E. WEST, Supervisor, Photographic
Technology Division, Eastman Kodak Co.,
Rochester, N.Y.
MR. ROY F. WESTON, President, Roy F. Weston,
Inc., Environmental Scientists and Engineers,
West Chester, Pa.
MR. THOMAS J. POWERS III, Technical Executive
Secretary, Technical Advisory and Investiga-
tions Branch, Federal Water Pollution Control
Administration, Cincinnati, Ohio.
DR. GRAHAM WALTON, Interim Technical Execu-
tive Secretary, Public Health Service, U.S. De-
partment of Health, Education, and Welfare,
Cincinnati, Ohio.
HURLON C. RAY, Committee Management Officer
Water Quality Standards Staff,
Federal Water Pollution Control Administration
U.S. Department of the Interior
633 Indiana Avenue NW.
Washington, D.C. 20242
Technical assistance
Federal Water Pollution Control Administration
ROBERT S. DAVIS, Aquatic Biologist.
IVAN W. DODSON, Soil Conservationist.
VERLYN T. ERNST, Staff Assistant.
ANN J. SCDORIS, Committee Clerk.
VIRGINIA K. DRUM, Clerk-Stenographer.
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preface
THE FEDERAL WATER POLLUTION CONTROL ACT, as amended by the
Water Quality Act of 1965, authorizes the States and the Federal Government
to establish water quality standards for interstate (including coastal) waters by
June 30, 1967. The water quality standards submitted by the States are subject to
review by the Department of the Interior and, if found consistent with Paragraph 3
of Section 10 of the Act, will be approved as Federal standards by the Secretary of
the Interior.
Paragraph 3, Section 10, reads as follows:
Standards of quality established pursuant to this subsection shall be such as to protect the
public health or welfare, enhance the quality of water and serve the purposes of this Act. In
establishing such standards the Secretary, the Hearing Board, or the appropriate state authority
shall take into consideration their use and value for public water supplies, propagation of fish
and wildlife, recreational purposes, and agricultural, industrial, and other legitimate uses.
If a State does not adopt water quality standards consistent with the above para-
graph, the Act provides the Secretary with the opportunity to set the standards.
On February 27, 1967, the Secretary established the first National Technical
Advisory Committee on Water Quality Criteria to the Federal Water Pollution Con-
trol Administration. The Committee's principal function was to collect into one
volume a basic foundation of water quality criteria. A smaller but equally important
function was to develop a report on research needs. This latter report will appear as
a separate publication. The Committee was subdivided to develop criteria for five
general areas of water use: (1) Recreation and Aesthetics; (2) Public Water Sup-
plies; (3) Fish, Other Aquatic Life, and Wildlife; (4) Agriculture; and (5) Industry.
An interim report was printed and presented to the Secretary of the Interior on
June 30, 1967. It was prepared primarily for two purposes: to assist in setting and
evaluating standards and for Committee review and comment.
After all the comments and revisions were considered, the various subcommit-
tees accepted a final version in the form here presented. Evaluation by knowledge-
able agencies and individuals is welcomed and any one who wishes to make
comments should forward them to:
Water Quality Standards Staff
Federal Water Pollution Control Administration
U.S. Department of the Interior
633 Indiana Avenue NW.
Washington, D.C. 20242
vi
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introduction
THE FWPCA is grateful for the assistance of the Committee in implementing the
Federal Water Pollution Control Act by recommending criteria for the various
legitimate water uses.
One troublesome problem encountered in the initial meetings oi the Committee
was that of semantics. The Committee faced the task of sorting out meanings among
the terms "criteria" and "standards." Regardless of any other uses of the words, the
following definitions are considered appropriate:
Standard—a plan that is established by governmental authority as a
program for water pollution prevention and abatement.
Criteria—a scientific requirement on which a decision or judgment
may be based concerning the suitability of water quality to support a
designated use.
The standards adopted by the States include water use classifications, criteria
necessary to support these uses, and a plan for implementation and enforcement.
Occasionally, among water pollution control authorities, the words "criteria" and
"requirement" are used interchangeably. The same can be said for the words
"standards" and "objectives."
The Federal Water Pollution Control Act authorizes the States to set standards.
Quality characteristics of a physical, chemical, or biological nature demanded by
aquatic life, industrial process, or other use, are requirements or criteria. This Report
of the National Technical Advisory Committee concerns criteria—a significant part
of water quality standards. The Committee considered the water use criteria set forth
in this report with the objective of assisting the State and Federal agencies in setting
and evaluating standards so they can meet water pollution abatement objectives.
The Committee was concerned about several issues relating to water quality
standards for the control and abatement of water pollution. Foremost among these
is the lack of adequate knowledge concerning many of the quality characteristics
upon which criteria and, hence, standards should be based. The unknowns still out-
weigh the knowns. Complicating factors in setting standards are varying natural
conditions affecting water quality, such as climate, geography, and geology of a
specific location. The Committee does not want to be dogmatic in recommending
these criteria. They are meant as guidelines only, to be used in conjunction with a
thorough knowledge of local conditions. Further, it is anticipated that future research
will provide considerable basis for refinements in the recommendations.
The Committee recognizes that the protection of water quality for legitimate
uses requires far more than scientific information. There is an urgent need for data
collected from systematic surveillance of waters and waste sources and for an
expanded research effort. Research needs are described in a separate document.
Achieving water quality goals, however, requires more than research and data
collection. It will depend on people: alert and responsible administrators at all
levels of government and industry, well-trained scientists, engineers, and technicians,
sympathetic legislators and stockholders, and an informed public.
Determining water quality criteria for various water uses is an important step in
solving the Nation's water pollution problems. Along with vigorous implementation
programs, it is a necessary step in achieving water quality management on a scien-
tific basis. The Committee firmly believes that preserving and improving the quality
of our water resources is well worth our best efforts.
Federal Water Pollution Control
Washington, D.C. Administration
April 1, 1968
VII
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contents
Page
Letter of Transmittal i
Committee Membership ii
Staff v
Preface vi
Introduction vii
Section I. Recreation and Aesthetics 1
Foreword 2
Summary of Recommendations 3
Aesthetics 4
Recreation 5
Literature Cited 14
Appendix 15
Section II. Public Water Supplies 17
Introduction 18
Discussion 19
Literature Cited 26
Section III. Fish, Other Aquatic Life, and Wildlife 27
Letter from the Chairman 28
Introduction 29
Zones of Passage 31
Summary and Key Criteria 32
Fresh Water Organisms 39
Marine and Estuarine Organisms 66
Wildlife 93
Literature Cited 99
Appendix (Glossary of Terms) 106
Section IV. Agricultural Uses 111
Introduction 112
Summary and Key Criteria 114
Farmstead Water Supplies 119
Scope of Task Force Considerations 119
Quality Considerations 124
Determination of Quality 126
Specific Recommendations 126
Livestock 129
Introduction and General Problem Areas 130
Description of Major Quality Considerations 134
Irrigation 143
Introduction: Water Quality Considerations for Irrigation 144
Specific Irrigation Water Quality Considerations for Arid
and Semiarid Regions 167
Specific Irrigation Water Quality Considerations for
Humid Regions 171
Other Considerations 175
Sampling and Analytical Procedures 178
Literature Cited 179
Section V. Industry 185
Introduction 186
Vlll
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Page
Summary and Key Criteria 187
Part I: Steam Generation and Cooling 190
Part II: Textile Lumber, Paper, and Allied Products 195
Textile Mill Products 195
Lumber and Wood Products 197
Paper and Allied Products 198
Part III: Chemical and Allied Products 200
Part IV: Petroleum and Coal Products 202
Part V: Primary Metals Industries 204
Part VI: Food and Kindred Products and Leather and Leather
Products 208
Food Canning Industries 208
Bottled and Canned Soft Drinks 211
Tanning Industry 213
Part VII: Cement Industry 214
Literature Cited 215
Index 216
tables
Section Page
II-l Surface water criteria for public water supplies 20
III-l Provisional maximum temperatures recommended as compatible with the
well-being of various species of fish and their associated biota 33, 43
III-2 Average turbidities found to be fatal to fish 47
III-3 Concentration of phenolic compounds that cause tainting of fish flesh 49
IH-4 Chemical composition of some algae from ponds and lakes in Southeastern
United States 55
III-5A, B Pesticides .- 62,64
III-6 Effect of alkyl-aryl sulfonate, including ABS, on aquatic organisms 65
IV-1 Key water quality criteria for farmstead uses 116
IV-2 Key water quality criteria for livestock uses 117
IV-3 Suggested guidelines for salinity in irrigation water 117
IV—4 Levels of herbicides in irrigation water at which crop injury has been
observed 118
IV-5 Recommended limits for chlorinated organic pesticides in farmstead waters 125
IV-6 Allowable concentrations of trace ions in farmstead waters 125
IV-7 Recommended limits for certain trace substances in farmstead waters 125
IV-8 Normal water consumption . .._ 130
IV-9 Examples of fish as indicators of water safety for livestock 131
IV-10 Proposed safe limits of salinity for livestock 134
IV-11 Suggested maximum allowable concentrations of certain inorganic elements
in farm animals water supply 135
IV-12 Proposed toxic dose ranges for arsenic 135
IV-13 Ether-resistant viruses 141
IV-14 Relative tolerance of crop plants to salt, listed in decreasing order of
tolerance 150
IV-15 Trace element tolerances for irrigation waters 152
IV-16 Relative tolerance of plants to boron 153
IV-17 Maximum permissible chloride contents in soil solution for various fruit-crop
varieties and rootstocks 156
IV-18 Levels of herbicides in irrigation water 158, 159
IV-19 Variations in dissolved solids, chemical type, and sediment. Rivers in arid
and semiarid United States 168
IV-20 Permissible number of irrigations in humid areas with saline water between
leaching rains for crops of different salt tolerance 174
ix
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Section Page
V-l Task forces and their assignments 187
V-2 Industrial and investor-owned thermal electric plant water intake, reuse and
consumption, 1964 188
V-3 Summary of specific water quality characteristics of surface waters that have
been used as sources of industrial water supplies 189
V—4 Quality characteristics of surface waters that have been used for steam
generation and cooling in heat exchangers 192
V—5 Quality requirements of water at point of use for steam generation and
cooling in heat exchangers 194
V-6 Quality characteristics of surface waters that have been used by the textile
industry 196
V-7 Quality requirements of water at point of use by the textile industry 196
V-8 Quality characteristics of waters that have been used by the lumber
industry 197
V-9 Quality characteristics of surface waters that have been used by the pulp
and paper industry 199
V-10 Quality requirements of water at point of use by the pulp and paper
industry 199
V-ll Process water intake by chemical and allied product industries with total
water intake of 20 or more bgy during 1964 201
V-12 Quality characteristics of surface waters that have been used by the chemical
and allied products industry 201
V-l 3 Quality requirements of water at point of use by chemical and allied
products industry 200
V-14 Quality characteristics of surface waters that have been used by the
petroleum industry 203
V-15 Quality requirements of water at point of use for the petroleum industry 203
V-l6 Quality characteristics of surface waters that have been used by the iron and
steel industry 206
V-17 Quality requirements of water at point of use for the iron and steel
industry 207
V-18 Quality characteristics of surface waters that have been used by the food
canning industry 210
V-l 9 Quality requirements of water at point of use by the canned, dried, and
frozen fruits industry 210
V-20 Quality requirements of water at point of use by the soft drink industry 212
V-21 Quality requirements of water at point of use by the leather tanning and
finishing industry 213
V-22 Quality characteristics of surface waters that have been used by the hydraulic
cement industry 214
V-23 Quality requirements of water at point of use for the hydraulic cement
industry 214
figures
IV-l Salt tolerance of vegetable crops 148
IV-2 Salt tolerance of field crops 149
IV-3 Salt tolerance of forage crops 149
IV—4 Nomogram for determining the SAR value of irrigation water and for esti-
mating the corresponding ESP value of a soil that is at equilibrium with
the water 165
V-l Pulp and paper industry: water intake, recycle, and discharge 198
V-2 Flow diagram showing water intake, recycling, and discharge in gallons per
ton of product for pulp and paper making by a typical mechanical
pulping mill 199
V-3 Uses of water and steam in canning 209
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Section I
recreation and aesthetics
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foreword
THE NATIONAL Technical Advisory Sub-
committee for Research and Aesthetics has
been asked to—
(1) recommend water quality criteria for recre-
ation and aesthetic uses; and
(2) identify research needs and priorities relat-
ing to water quality for recreation and aes-
thetic uses.
This report is addressed to the first of these as-
signments. It includes observations on aesthetic
and recreation values as these are understood by
the Subcommittee. Criteria—descriptive and nu-
merical—are based upon evaluation of existing
information by members of the Subcommittee and
others whose counsel has been sought informally.
There are serious gaps, and considerable conflict,
in available information. Research recommenda-
tions are offered in a separate paper.
The Subcommittee is grateful for the opportu-
nity to assist in implementing the Water Quality
Act of 1965 by recommending criteria for aes-
thetic and recreation purposes. The Subcommittee
notes, however, that the protection of water qual-
ity for desired uses requires far more than tech-
nical data. There is urgent need for systematic
surveillance (traditional sanitary surveys broad-
ened to include aesthetic qualities) of waters and
of waste sources to make effective use of criteria
in practice. And in the last analysis, accomplish-
ment of water quality goals will depend on
people: alert and responsible administrators at
all levels of government and industry, well-trained
scientists, engineers, and technicians, sympathetic
legislators and stockholders, and an informed
public.
With this somewhat modest view of its assign-
ment and its performance, the Subcommittee is
pleased to offer this report. In the interest of or-
derly exposition, the Subcommittee has chosen to
consider aesthetics first, followed by recreation.
NOTES
1. The Subcommittee has found that criteria are needed
for water quality management for de facto, as well as
designated, water uses. This finding is reflected through-
out the report and particularly in criteria for recreation.
2. The Subcommittee has not proposed delicate grada-
tions in criteria, assuming that in natural waters—even
for specific uses at specific points—management neces-
sarily involves sizable reaches of water.
3. The recommendations in this report should be con-
sidered as subject to periodic adjustment as better in-
formation becomes available.
-------
tected by development of appropriate cri-
teria for each individual case.
Recreation
summary
of recommendations
Aesthetics
A. General Requirements
I. All surface waters should be capable of
supporting life forms of aesthetic value.
II. Surface waters should be free of sub-
stances attributable to discharges or wastes
as follows:
(a) Materials that will settle to form ob-
jectionable deposits.
(b) Floating debris, oil, scum, and other
matter.
(c) Substances producing objectionable
color, odor, taste, or turbidity.
(d) Materials, including radionuclides, in
concentrations or combinations
which are toxic or which produce
undesirable physiological responses
in human, fish, and other animal life
and plants.
(e) Substances and conditions or combi-
nations thereof in concentrations
which produce undesirable aquatic
life.
B. Desirable Additional Requirements
I. The positive aesthetic values of water
should be attained through continuous en-
hancement of water quality.
II. The aesthetic values of unique or outstand-
;nt: -vaters should he recognized and ";ro-
A. General Recreational Use of Surface Waters
I. Surface waters, with specific and limited
exceptions, should be suitable for human
use in recreation activities not involving
significant risks of ingestion without refer-
ence to official designation of recreation
as a water use. For this purpose, in addi-
tion to aesthetic criteria, surface waters
should be maintained in a condition to
minimize potential contamination by uti-
lizing fecal coliform criteria for monitor-
ing. In the absence of local epidemiologi-
cal experience, the Subcommittee sug-
gests an average not to exceed 2,000
fecal coliforms per 100 ml and a maxi-
mum of 4,000 per 100 ml, except in
specified mixing zones adjacent to out-
falls.
II. Surface waters, with specific and limited
exceptions, should be of such quality as
to provide for the enjoyment of recrea-
tion activities based upon the utilization
of fishes, waterfowl, and other forms of
life without reference to official designa-
tion of use. The Subcommittee recom-
mends by reference criteria developed by
the National Technical Advisory Sub-
committee on Fish, Other Aquatic Life,
and Wildlife for guidance relative to
various species and waters.
III. Species available for harvest by recreation
users should be fit for human consump-
tion. In areas where taking of mollusks is
a recreational activity, the criteria shall be
guided by the U.S. Public Health Service
manual, "Sanitation of Shellfish Growing
Areas," 1965 revision.
B. Enhancement of Recreation Value of Waters
Designated for Recreation Uses Other Than
Primary Contact Recreation
I. In waters designated for recreation use
other than primary contact recreation, the
fecal coliform content, as determined by
either multiple-tube fermentation or mem-
brane filter techniques, should not exceed
a log mean of 1,000/100 ml, nor equal or
exceed 2,000/100 ml in more than 10%
cf the samples.
II. :n waters designated for recreation use,
-------
optimum conditions for recreation based
upon utilization of fish, other aquatic life,
and wildlife should apply, with specific and
limited exceptions. The Subcommittee en-
dorses by reference the criteria for these
purposes recommended by the National
Technical Advisory Subcommittee on
Fish, Other Aquatic Life, and Wildlife.
C. Primary Contact Recreation
I. Criteria for mandatory factors.
(a) Fecal coliform should be used as the
indicator organism for evaluating the
microbiological suitability of recrea-
tion waters. As determined by mul-
tiple-tube fermentation or membrane
filter procedures and based on a mini-
mum of not less than five samples for
any 30-day period of the recreation
season, the fecal coliform content of
primary contact recreation waters
shall not exceed a log mean of 200/
100 ml, nor shall more than 10 per-
cent of total samples during any 30-
day period exceed 400/100 ml.
(b) In primary contact recreation waters,
the pH should be within the range of
6.5-8.3 except when due to natural
causes and in no case shall be less
than 5.0 nor more than 9.0. When
the pH is less than 6.5 or more than
8.3, discharge of substances which
further increases unfavorable total
acidity or alkalinity should be limited.
II. Criteria for desirable factors.
(a) For primary contact waters, clarity
should be such that a Secchi disc is
visible at a minimum depth of 4
feet. In "learn to swim" areas, the
clarity should be such that a Secchi
disc on the bottom is visible. In div-
ing areas, the clarity shall equal the
minimum required by safety stand-
ards, depending on the height of the
diving platform or board.
(b) In primary contact recreation waters,
except where caused by natural con-
ditions, maximum water temperature
should not exceed 85 F (30 C).
III. Marine waters
The Subcommittee suggests, as a gen-
eral practice, application of a single set of
criteria for fresh, estuarine, and marine
waters.
aesthetics
-------
Observations on aesthetic values
It is not surprising that water has occupied an
important position in the concerns of man. The
fate of tribes and nations, cities and civilizations
has been determined by drought and flood, by
abundance or scarcity of water since the earliest
days of mankind.
Artists have reflected man's fascination with
water. Literature and art of a variety of cultures
dwell upon brooks, waves, waterfalls, and lakes
as superlatives among the delights of the environ-
ment.
Aesthetically pleasing waters add to the quality
of human experience. Water may be pleasant to
look upon, to walk or rest beside, to contemplate.
It may provide a variety of active recreation ex-
perience. It may enhance the visual scene wher-
ever it appears, in cities or wilderness. It may
enhance values of adjoining properties, public and
private. It may provide a focal point of pride
in the community.
The appearance of pollution and the fear of
pollution reduces aesthetic value; the knowledge
that water is clean enhances both direct and in-
direct aesthetic appreciation.
The Subcommittee is charged with recommend-
ing aesthetic criteria for water itself. But the Sub-
committee notes that the aesthetic appeal of visual
scenes in which water is an element involves the
uses and activities on the water's surface; i.e.,
boats, ships, wildlife.
Thus the management of water for aesthetic
purposes must be planned and executed in the
context of the uses of the land, the shoreline, and
the water surface.
It is clear that Americans are becoming increas-
ingly concerned about aesthetic quality of the
physical environment. And it seems probable that
aesthetic expectations will rise with increases in
education and leisure, and that these rising ex-
pectations will be reflected in continuing and
accelerated public demand for "clean" water. The
recent history of public policy in water pollution
control would seem to support these observations.
On a number of occasions, the President has
expressed a growing national concern for the qual-
ity of the environment and specifically for the
quality of water resources. In his 1965 message
on "The Natural Beauty of Our Country," the
President said:
A prime national goal must be an environment that is
pleasing to the senses (as well as) healthy to live in.
In the same message, the President called for
intensified action to clean up "waterways that were
once sources of pleasure and beauty and recrea-
tion," but are now "objectionable to sight and
smell," as well as dangerous for human contact.
The concern of the new conservation, the Presi-
dent has said, "Is not just man's welfare, but the
dignity of man's spirit."
Congress has affirmed and reaffirmed its deter-
mination to enhance water quality in a series of
actions strengthening the Federal role in water
pollution control and strengthening Federal sup-
port for water pollution control programs of State
and local governments and industry.
In a number of States, political leaders and
voters have overwhelmingly supported costly pro-
grams to restore water quality, with aesthetics—
as well as recreation—as one of the values in-
volved.
The recognition, identification, and protection
of the aesthetic values and qualities of water should
be an objective of all water quality management
programs. Withdrawn water that is not consumed
returns to the common supply. The retention of
suitable characteristics, including aesthetic quality,
in the common supply is more likely to be achieved
through control of discharges at the source than
by excessive dependence upon assimilation by re-
ceiving waters. The Subcommittee emphasizes the
values that aesthetically pleasing water provides
are most urgently needed where pollution prob-
lems are most difficult—in cities, and particularly
in the central portions of cities where population
and industry are likely to be most heavily concen-
trated.
Recommended criteria for aesthetic
purposes
Recommendation: All surface waters should contribute
to the support of life forms of aesthetic value.
This recommendation is made in recognition
of the significance of fishes, waterfowl, and other
water-dependent species to human aesthetic satis-
faction.
Wildlife is a significant element of the aesthetics
of the physical environment, adding beauty in a
variety of forms and life to otherwise static scenes.
Beyond the direct experience of viewing (which
may include educational and recreational nature
study) is the aesthetic satisfaction of knowing
that these life forms are present. Conversely,
periodic disruptions in the aquatic environment
by pollution—reflected in fish kills, damage to
waterfowl, odors, noxious vegetative growths—de-
grade aesthetic qualities and appreciation. These
aesthetic losses extend beyond the periods during
which the conditions may occur. A river that is
offensive periodically will lose much of its aes-
thetic value until suitable quality conditions are
-------
restored—and maintained consistently.
This recommendation, as well as others relative
to aesthetics, is to be applied in the context of
local conditions.
Numerical criteria of the National Technical
Advisory Subcommittee on Fish, Other Aquatic
Life, and Wildlife will provide guidance for water
management.
In addition to supporting life forms of aesthetic
value, surface waters should themselves be aes-
thetically pleasing. Because natural conditions vary
widely, the Subcommittee recommends a series
of descriptive rather than numerical criteria for
this purpose. The criteria are intended in general
terms to provide for the protection of surface
waters from substances or conditions which might
degrade or tend to degrade the aesthetic quality
of water from other than natural sources. In
this context "natural sources" includes only sub-
stances or conditions which may affect water qual-
ity independent of human activities. Human ac-
tivities which cause degradation from otherwise
natural sources, such as accelerated erosion from
surface disturbances, are not considered to be
natural. The criteria are intended to cover degra-
dation "from discharges or waste." This phrase
is intended to cover pollution from all sources
attributable to human activities whether carried
in over-the-surface flow, point discharges, or sub-
surface drainage.
The word "free" in the list of minimum require-
ments is acknowledged to be a practical impos-
sibility; the presence of pollutants in some degree
is inevitable. The Subcommittee assumes that ad-
ministrators and courts will interpret the term in
a manner that will accomplish the purposes of
the criteria.
Recommendation: Surface waters should be free of
substances attributable to discharges or waste as
follows:
(a) Materials that will settle to form objectionable
deposits.
(b) Floating debris, oil, scum, and other matter.
(c) Substances producing objectionable color, odor,
taste, or turbidity.
(d) Materials, including radionuclides, in concentra-
tions or combinations which are toxic or which
produce undesirable physiological responses in
human, fish and other animal life, and plants.
(e) Substances and conditions or combinations thereof
in concentrations which produce undesirable
aquatic life.
Substances and conditions referred to in (e), above,
would include factors such as excessive nutrients and
temperature elevation. Undesirable aquatic life would
include objectionable abundance of organisms such as
a bloom of blue-green algae resulting from discharge
of a waste with r high nutrient content and an elevated
temperature. We would encourage the use of numerical
limitations on nutrients in specific waters where present
or future knowledge may perm,I cr other water use
requirements (e.g., public water supply) justify such
actions. However, the Subcommittee feels their recom-
mending numerical limitations that would meet the
many varying requirements of aesthetics for individual
waters and regions would result in nothing more than
a welter of numbers.
The Subcommittee wishes to emphasize that
aesthetic qualities—notably color and clarity—of
natural waters vary sharply among regions and
within regions or even on specific streams, lakes,
reservoirs, bays, and estuaries. The recommended
criteria are intended to be applied in the context of
natural conditions.
The Subcommittee considered recommending
numerical criteria for aesthetic uses. It concluded
that numbers would add little to the usefulness
of descriptive criteria because the effect of vari-
ous substances on waters is so largely dependent
on local conditions.
Quality above minimum requirements
The Subcommittee notes that "Guidelines for
Establishing Water Quality Standards for Inter-
state Waters," published by the Department of the
Interior in 1966, provides that "water quality
standards should be designed to enhance (italics
supplied) the quality of water" and "in no case
will standards providing for less than existing
water quality be acceptable."
Generally speaking—especially when psycho-
logical factors are considered—the aesthetic values
of water are enhanced by continuing improvement
in quality conditions in microbiological, chemical,
and physical terms and reduced as quality de-
clines. Aesthetic values may be best realized by
continuing efforts, as implied by the Water Quality
Act of 1965, toward enhancement of water quality
for all uses.
Unique or outstanding waters
Certain bodies of water in the United States
merit special considerations in establishing water
quality criteria and standards. Examples include
Lake Tahoe, Crater Lake, portions of Biscayne
Bay and other coastal and estuarine areas, rivers
(including a number which may be designated as
"scenic" or "wild" rivers under State or Federal
law) reservoirs, and lakes—waters which by rea-
son of clarity, color, scenic setting, or other char-
acteristics provide aesthetic values of unique or
soeciai interest. The Subcommittee recommends
that such special waters be identified and specific
standards developed in each case to protect thei-r
unique Dallies.
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recreation
Observations on recreation values
Recreation uses of water in the United States
have historically occupied an inferior position in
practice and law relative to other uses.
Where maintenance of recreation quality water
placed no significant burden on other water users,
recreation has customarily been considered an ap-
propriate use. If other uses degraded quality below
recreation quality, the recreation user has usually
been expected to seek alternative waters, a task
constantly rendered more difficult by rapidly ex-
panding urbanization and industrialization.
In a number of Western States, recreation does
not appear in the roster of "beneficial uses" enu-
merated by statute. The recognition of recreation
as a benefit and a purpose of water resource de-
velopment is a matter of recent history for such
Federal agencies as the Corps of Engineers, the
Bureau of Reclamation, and the Soil Conservation
Service.
The reasons for these priorities in the uses of
water are found in the transition from an agrarian
to an industrial and urban society. Now the Nation
faces a new order of social problems including, for
the first time in history, a serious concern for the
creative uses of the increasing amounts of leisure
available to our people. Today there is a growing
realization that recreation is a full partner in water
use; one that, with associated services, represents
a multimillion dollar industry with substantial
prospects for future growth as well as an important
source of psychic and physical relaxation.
Outdoor recreation is a preferred form of leisure
activity for increasing millions of Americans;
water and shorelines serve as a focal point for
many preferred forms of outdoor recreation. Quan-
tity, location, and accessibility as well as quality
of water are prime factors in satisfying outdoor
recreation demands. These facts are set forth in
"Outdoor Recreation for America," the 1962 re-
port of the Outdoor Recreation Resources Review
Commission (ORRRC), and are confirmed by
subsequent surveys of outdoor recreation activities
and demands carried out by the Bureau of Out-
door Recreation (BOR), Department of the
Interior.
One of the major findings and pervasive themes
of the ORRRC report was that most people seek-
ing outdoor recreation (90 percent of all Ameri-
cans) seek it associated with water—to sit by,
to walk alongside, to swim and to fish in, and to
boat on.
Based on a 1960 survey, ORRRC found—for
example—that swimming was second among oat-
door recreation activities and was Jikei« to be
-------
the most popular by the turn of the century. Boat-
ing and fishing were among the top 10 activities.
Walking, camping, picnicking, and hiking—also
high on the user preference list—are more attrac-
tive, higher quality experiences near clean water.
A 1965 survey by the Bureau of the Census,
Department of Commerce, for BOR indicates that
present and anticipated increases in all water-re-
lated activities far surpass ORRRC projections.
BOR's 1965 survey found—for example—that
the popularity of swimming, now second only to
"walking for pleasure," is increasing so fast that
it is expected to be the number one outdoor ac-
tivity by 1980 and continue to hold that place
in 2000.
Expressed in other terms, BOR found that out-
door swimming "participation occasions" increased
44 percent between 1960 and 1965 (while the
population of individuals 12 years old and older
increased 8 percent). Between 1965 and 1980,
BOR expects that swimming will increase 72 per-
cent (while population is expected to increase
29 percent), and between 1965 and 2000, 207
percent (while population is expected to increase
76 percent).
Expressed in terms of individuals, rather than
"occasions," BOR's 1965 survey found that 49
percent of the population (12 years old and older)
went swimming outdoors that year, an increase of
15 percent since 1960. Comparable figures for
some other water-related activities:
Fishing—30 percent of population participated,
an increase of 12 percent since 1960.
Boating (other than canoeing and sailing)—
24 percent, an increase of 18 percent.
This intimate connection between water and
recreation suggests the need for coordination of
outdoor recreation planning programs and water
resources planning programs. Under the Land
and Water Conservation Fund Act of 1965, and
the Water Quality Act of 1965, the States are
required to prepare comprehensive long-range
plans for meeting the outdoor recreation needs of
their people, and for the management of water
quality on interstate waters, respectively. State
and Federal water quality officials should draw
upon statewide outdoor recreation plans (and the
nationwide outdoor recreation plan now being
prepared by the Bureau of Outdoor Recreation)
for guidance in assessing recreation needs, and in
developing and applying standards and criteria to
waters under their jurisdictions. Similar coor-
dination should be effective between water quality
and comprehensive water resources planning pro-
grams now underway or planned for river basins
throughout the country.
The Subcommittee emphasizes that the manage-
ment of water resources to enhance recreational
opportunities requires more than the maintenance
of water quality. In addition to quantity, location,
and accessibility of water, management for recrea-
tion may involve seasonal and even daily water
level regulation during seasons and hours of peak
use.
Recreation activities for which criteria
are recommended
The Subcommittee has been asked to recom-
mend criteria for water to be used for recreation.
In draft materials prepared for consideration by
the Subcommittee, and in much of the available lit-
erature, water quality criteria for recreation con-
centrate on the protection of the health and safety
of the recreation user.
It is the Subcommittee's conviction that water
quality management programs for recreation
should include criteria to—
(a) provide for and enhance general recreation
use of surface waters;
(b) enhance recreation value of waters desig-
nated for recreation use; and
(c) provide special protection for the recreation
user where significant body contact with
water is involved.
Criteria for these purposes are set forth in suc-
ceeding sections.
Criteria for general recreational use
of surface waters
The Subcommittee has concluded for reasons
set forth below that it is necessary to recommend
criteria for general recreation use of surface
waters without reference to specific designation
of recreation as a water use.
Considerations related to the recreation user
Recommendation: Surface waters should be suitable
for use in "secondary contact" recreation—activities
not involving significant risks of ingestion—without
reference to official designation of recreation as a
water use. For this purpose, in addition to aesthetic
criteria, surface waters should be maintained in a
condition to minimize potential health hazards by
utilizing fecal coliform criteria. In the absence of local
8
-------
epidemiological experience, the Subcommittee recom-
mends an average not exceeding 2,000 fecal coliforms
per 100 ml and a maximum of 4,000 per 100 ml,
except in specified mixing zones adjacent to outfalls.
This level of fecal coliforms could be expected
when concentrations of viral and other pathogens
in receiving waters have been reduced to less than
infectious levels for casual water contact by hu-
mans, with the risk considered to be one-tenth
that for primary contact recreation (see criteria
for primary contact recreation on p. 12). Further
research will be necessary to arrive at precise cri-
teria for secondary contact recreation activities.
This recommendation is intended to provide for
the enjoyment, in relative safety, of uses custom-
arily described as "secondary contact recreation,"
including boating, fishing, and limited contact with
water incident to shoreline activities. Swimming,
wading by children, and other activities usually
referred to as "primary contact recreation" are not
adequately provided for by this recommendation.
The recommendation recognizes the undeniable
attraction of water to human beings: water has
value, and is used, for a variety of recreational
activities without regard to specific management
for or designation of these uses.
In the Subcommittee's opinion, public policy
and water quality criteria should provide for these
values and uses as a normal and desirable manage-
ment objective on surface waters of the United
States.
The Subcommittee notes certain qualifications in
its recommendation. There are, depending on local
conditions, waters—typically below points of dis-
charge and before mixing—where recreational uses
should be discouraged, or in certain cases pro-
hibited. (The Subcommittee assumes that zones
for mixing are limited, and are specified and de-
fined in water quality programs.) Quite apart
from water quality, physical hazards—such as in-
tensive navigation use—may make recreation use
undesirable. If the Subcommittee's recommenda-
tion is accepted, an additional burden will be
placed upon public agencies to develop positive
programs to discourage recreation use where such
use is clearly inadvisable.
Time is a factor in the Subcommittee's recom-
mendation. The Subcommittee assumes that plans
and programs for implementation of standards
prepared by the States will set forth schedules for
accomplishment of water quality criteria for vari-
ous uses including secondary contact recreation
uses.
The burden of the Subcommittee's finding is
that surface waters—wherever there are people—
have recreational potential, are likely to be used
for recreation even if grossly polluted, and provide
increased recreation value as quality improves.
Thus both protecting the public health and en-
hancement of water quality for human satisfaction
support the Subcommittee's recommendation. As
in the case of aesthetic value, demands on water
for recreation are likely to be most intense in
urban areas, where suitable quality is most difficult
to achieve.
The Subcommittee emphasizes that this recom-
mendation is a suggested minimum requirement.
Many of the most-sought-after forms of water rec-
reation as described in user preference studies by
the Bureau of Outdoor Recreation—swimming
and "going to the beach," water skiing, surfing—
call for water of significantly lower microbiological
content than recommended here. Thus, while reali-
zation of secondary contact recreation water would
involve a substantial upgrading of the quality of
significant portions of surface waters, the mini-
mum level suggested here still constitutes a severe
limitation on the potential recreation value of
surface waters. The Act of Congress under which
these criteria are being developed specifies that
one of its purposes is to enhance the value of the
Nation's water resources. The Subcommittee em-
phasizes strongly that continuing improvement be-
yond the minimum levels specified for aesthetics in
this section will add to the recreation value of
surface waters.
In addition to criteria to permit safe public en-
joyment of secondary contact recreation, the Sub-
committee has concluded that a companion recom-
mendation is necessary to provide for recreation
based on utilization of fishes and other aquatic or
water-related species as a general use of surface
waters.
Recommendation: Surface waters, with specific and
limited exceptions, should be of such quality as to
provide for the enjoyment of recreation activities based
upon the' utilization of fishes, waterfowl and other
forms of life, without reference to official designation
of use. The Subcommittee recommends by reference
criteria developed by the National Technical Advisory
Subcommittee on Fish, Other Aquatic Life, and Wild-
life for guidance relative to various species and waters.
Recreation based on utilization of aquatic and
water-related animals is, in number of participants,
a major recreation use of surface waters. The Sub-
committee suggests that the maintenance and pro-
duction of fish and wildlife utilized for recreation
purposes must be assumed to be an objective of
management of surface waters for general recrea-
tion use.
As in the preceding section, exceptions should
be confined to specific mixing zones adjacent to
outfalls.
The 1965 survey by the Bureau of the Census
-------
reported that over 42 million Americans engaged
in recreational fishing—not counting children
under 12 years of age. Over li million hunted
waterfowl. Recreation based upon taking of mol-
lusks and crustaceans is significant, although data
on use are not available. (Mollusks and crusta-
ceans, in varying degrees, tend to concentrate cer-
tain pollutants beyond concentrations in water.
Note is made of this fact in a succeeding recom-
mendation. )
Another Subcommittee has been asked to rec-
ommend criteria for fish and wildlife. The recom-
mendation in this section is made to underscore
the nearly universal value and appeal of surface
waters for recreation based on these life forms, and
to recommend that these forms of recreation be
provided for as a general recreation use of surface
waters.
The Subcommittee realizes that optimum condi-
tions for fish and wildlife are not attainable in all
surface waters, even with the recommended excep-
tions for mixing zones. Significant recreation op-
portunities based on fish and wildlife may, how-
ever, be provided by less than optimum conditions,
and these recreation values may be expected to
increase as conditions are improved under careful
management.
The use of specific waters for recreation based
upon fish and wildlife may be undesirable for a
number of reasons, including potential conflicts
among recreation activities. Limitations on the
recreational values of waters capable of providing
recreational fishing and hunting under practical
management for these purposes should not, how-
ever, be imposed by water quality.
The effect of the Subcommittee's recommenda-
tion is that recreation based upon utilization of
fishes, other aquatic life forms, and waterfowl is
logically assumed to be an objective of the man-
agement of surface waters. Criteria which fail to
provide for these recreation activities constitute a
limitation on recreation uses, except where such
use is inappropriate for reasons other than water
quality.
A significant part of fishing, hunting, and similar
activities is consumption of the species involved.
Water quality management should protect this use
by controlling taste, odor, and safeness for con-
sumption of harvestable species. It is the position
of the Subcommittee that the recreation harvester
of aquatic life is entitled to the same protection
afforded the commercial producer and consumer.
Recommendation: Species available for harvest by
recreation users should be fit for human consumption.
In areas where taking of mollusks is a recreational
activity, the criteria shall be guided by the U.S. Public
Health Service manual "Sanitation of Shellfish Growing
Areas," 1965 revision.
Criteria for the enhancement of
recreation value of waters designated
for recreation uses other than primary
contact recreation
The preceding recommendations on criteria for
general recreational use of surface waters note
that regardless of whether or not such use is en-
couraged, people are drawn to and make use of
water for a variety of recreation activities, and
suggest criteria in recognition of this fact.
The recommendations in this section are in-
tended to apply where recreation is a designated
use for water quality management purposes (but
not in cases where primary contact recreation
is involved).
Water quality managers and recreation-supply-
ing agencies share the opportunity and obligation
to seek high quality in waters designated for recre-
ational use and especially so in waters associated
with public or private areas and facilities provided
for recreation uses.
Water suitable for primary contact recreation
uses is a desirable goal on all waters designated for
recreation use. Criteria for primary contact use
(set forth in a succeeding recommendation) should
be applied wherever feasible and should be ap-
proached as closely as possible wherever recreation
is a designated water use—especially where recrea-
tion use is encouraged by facilities such as boat
launching ramps, campgrounds, fishing access
points, and shoreline trails. Where wading and
dabbling by children is a customary use in these
areas, primary contact criteria should apply.
Where primary contact criteria can be applied,
health hazards are minimized and the full range
of recreation opportunities assured.
Aesthetic criteria apply, of course, to waters
designated for recreation use. In addition, the
Subcommittee recommends fecal coliform criteria
designed to enhance and protect recreation use.
This recommendation is intended to establish
microbiological criteria for "secondary contact"
recreation activities on waters designated for
recreation use. It is more stringent than the recom-
mendation providing for secondary contact recrea-
tion on surface waters generally.
Recommendation: In waters designated for recreation
uses other than primary contact recreation, the Sub-
committee recommends that the fecal coliform content,
as determined by either multiple-tube fermentation or
membrane filter techniques, should not exceed a log
mean of 1,000/100 ml, nor equal or exceed 2,0007
100 ml in more than 10 percent of the samples.
10
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Additional reductions of microbiological con-
tent will serve to further protect public health and
enhance and encourage recreation enjoyment.
The Subcommittee recommends further that op-
timum conditions for recreation based upon fish,
other aquatic forms, and water-related wildlife be
assumed to be an objective of management of
waters designated for recreation use.
Recommendation: In waters designated for recreation
use, optimum conditions for recreation based upon
utilization of fish, other aquatic life, and wildlife should
apply, with specific and limited exceptions. The Sub-
committee endorses by reference criteria for these pur-
poses recommended by the National Technical Ad-
visory Subcommittee on Fish, Other Aquatic Life, and
Wildlife.
The Subcommittee has noted earlier its judg-
ment that fishing, certain forms of hunting, and
other recreation activities based upon fish and
wildlife should be considered as a general recrea-
tion use of surface waters, with specific and limited
exceptions.
It follows that, where recreation is a designated
water use calling for special quality management
efforts, optimum conditions for the species which
provide these forms of recreation—as recom-
mended by the National Technical Advisory Sub-
committee on Fish, Other Aquatic Life, and Wild-
life—should be assumed to be a management ob-
jective.
The Subcommittee notes that, even in major
water areas designated for recreation use, water
used for mixing adjacent to outfalls may fall below
optimum conditions in specific and limited areas.
The Subcommittee also notes that certain water-
related recreation activities at a given site may
conflict during certain seasons and times. The limi-
tations on recreation use should not, however, be
imposed by water quality.
Criteria for primary contact recreation
On the basis of microbiological criteria, water
quality managers customarily divide water recrea-
tion users into two groups: those engaged in pri-
mary contact recreation and those engaged in
secondary contact recreation.
The Subcommittee has provided for secondary
contact recreation in earlier recommendations and
will not deal with criteria for the purpose in this
section.
The Subcommittee defines primary contact rec-
reation as activities in which there is prolonged and
intimate contact with the water involving consider-
able risk of ingesting water in quantities sufficient
to pose a significant health hazard. Examples are
wading and dabbling by children, swimming, div-
ing, water skiing, and surfing. (Secondary contact
sports include those in which contact with the
water is either incidental or accidental and the
probability of ingesting appreciable quantities of
water is minimal.)
While similarities in water contact involved in
trout or surf fishing and wading and dabbling by
children seem to call for their inclusion in the
same category, there are significant differences.
Children are more likely to ingest water and may
be more susceptible to pathogens in water. In
this light, it would seem wise to set a goal of cri-
teria for the protection of primary contact recrea-
tion for most waters adjacent to organized recrea-
tional areas such as picnicking areas and camping
grounds customarily used by children.
The establishment of special criteria (e.g., public
health requirements) necessary for the protection
of the primary contact recreation user has been a
major problem for the Subcommittee. Moreover,
in recommending specific water quality criteria for
this purpose the Subcommittee is faced with a
sharp dilemma—that of balancing reasonable safe-
guards for the public health and physical well-
being against possible undue restrictions on the
availability of waters for contact recreation. The
problem is further complicated by the inadequacy
of studies correlating epidemiological data on
water-borne diseases with degrees of pollution in
recreational waters.
Two factors, microbiological contamination and
pH, are so intimately associated with the health
and physical well-being of the primary contact
recreation user that they should be considered
in management of waters for use for these pur-
poses. While the inclusion of pH might be ques-
tioned, the Subcommittee believes its relation to
eye irritations and subsequent infections justifies
its consideration (see appendix at end of this sec-
tion). None would question the necessity of in-
cluding microbiological criteria in a "must" cate-
gory, thus leaving only the question of what
indicators and what limits should apply.
In attempting to resolve the safety versus un-
necessary restriction dilemma, the Subcommittee
considered at length the selection of most useful
indicators of contamination. The ideal solution
might be in the continuous and instantaneous de-
termination of pathogens. However, time factors,
multiplicity, and complexity of tests, economics of
equipment, and other materials, and manpower
requirements rule out use of pathogens as criteria
for general application. The optimum solution
then becomes one of monitoring an indicator
organism.
11
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The feces and urine of warmblooded animals
are the most significant potential sources of water-
borne pathogens capable of infecting man. Man
has contracted cholera, typhoid, leptospirosis,
schistosomiasis, and other diseases, with water as
the vector, where the source of contamination was
traced to animals. Time lapse and magnitude of
contamination are critical factors in the degree of
hazard. The problem now becomes one of selecting
an appropriate indicator and numerical limits that
will indicate contamination by excreta of warm-
blooded animals.
The use of total coliforms as an indicator has a
long history, most recently through counts on
membrane filters. While the total coliforms count
may be a satisfactory indicator in certain respects,
the Subcommittee believes that the variable corre-
lation of total colif orm content with contamination
by excreta suggests that coliforms are not a satis-
factory indicator of the possible presence of patho-
gens in recreational waters.
The portion of the total coliforms in water that
are of fecal origin may range from less than 1 per-
cent to more than 90 percent. At the 1 percent
level, a limit of 1,000/100 ml total coliforms
would constitute an undue limitation on availabil-
ity of water for contact recreation. At the 90 per-
cent level, a limit of 1,000/100 ml would consti-
tute a threat to the health of the contact recreation
user. Thus, total coliform criteria are not adequate
for determining suitability of waters for use for
contact recreation.
Fecal streptococci in combination with total
coliforms are being used in sanitary evaluation.
Selection of techniques to be applied and the inter-
pretation of results are in a state of flux and un-
certainty. Problems include the unresolved ques-
tion of whether or not all types of fecal strepto-
cocci found in warmblooded animals are revealed
by the tests, the fact that appreciable numbers of
streptococci from other sources (plants and in-
sects) yield positive test results, and added time
and manpower requirements for monitoring agen-
cies. Fecal streptococci should not be used as pri-
mary criteria, but are useful as a supplement to
fecal coliforms where more precise determination
of sources of contamination is necessary.
It is the Subcommittee's opinion that of the
groups or organisms commonly employed in evalu-
ating sanitary conditions in surface waters, fecal
coliform is by far the best choice for use in criteria
for contact recreation. Two facts will demonstrate
that fecal coliforms are superior indicators of re-
cent contamination with feces of warmblooded
animals. Approximately 95 percent of the total
coliform organisms in the feces of both birds and
mammals yield positive fecal coliform tests. A
similar portion of the total coliform organisms in
samples of uncontaminated soils and plant mate-
rials yield negative fecal coliform tests. It is im-
portant to note that use of fecal coliforms as an
indicator does not add to the complexity or ex-
pense of monitoring.
There is an urgent need for research to refine
correlations of various indicator organisms, in-
cluding fecal coliforms, to water-borne disease.
The Subcommittee feels that the Public Health
Service's three epidemiological studies on bathing
water quality and health are the only base available
for setting criteria. These studies were far from
definitive and were conducted before the accept-
ance of the fecal coliform as a more realistic meas-
ure of a health hazard. The studies at the Great
Lakes (Mich.) and the Inland River (Ohio)
showed an epidemiologically detectable health ef-
fect at levels of 2,300-2,400 coliforms per 100 ml.
Later work on the stretch of the Ohio River where
the study had been done indicated that the fecal
coliforms represented 18 percent of the total coli-
forms. This would indicate that detectable health
effects may occur at a fecal coliform level of about
400 per 100 ml; a factor of safety would indicate
that the water quality should be better than that
which would cause a health effect.
The Santee project correlated the prevalence of
virus with fecal coliform concentrations following
sewage treatment. Virus levels following secondary
treatment can be expected to be 1 PFU per milli-
liter with a ratio of one virus particle per 10,000
fecal coliforms. A bathing water with 400 fecal
coliforms per 100 ml could be expected to have
0.02 virus particles per 100 ml (one virus particle
per 5,000 ml.)
On these bases, the committee recommends the
following.
Recommendation: Fecal coliforms should be used as
the indicator organism for evaluating the microbiologi-
cal suitability of recreation waters. As determined by
multiple-tube fermentation or membrane filter pro-
cedures and based on a minimum of not less than five
samples taken over not more than a 30-day period,
the fecal coliform content of primary contact recreation
waters shall not exceed a log mean of 200/100 ml, nor
shall more than 10 percent of total samples during any
30-day period exceed 400/100 ml.
It is the position of the Subcommittee that, if
neither excessive health hazards nor undue restric-
tion on availability of recreational waters are to
occur, sanitary criteria for water contact recreation
should reflect the foregoing recommendations. The
Subcommittee recognizes that localized bacterial
standards may be justified, if based on sufficient
experience, sanitary surveys, or other control and
monitoring systems. For greatest value, such ac-
12
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tions should include a thorough analysis of the
sources of contamination and the degree of threat
of pathogens from specific sources.
The Subcommittee notes that fecal discharges
from vessels are individually a small contribution
to contamination and may not be reflected in bac-
terial sampling, but represent a rather direct health
hazard and must be controlled in or near primary
contact recreational areas.
In addition to sanitary criteria, the Subcommit-
tee recommends criteria on pH for primary con-
tact recreation waters. While the Subcommittee
recognizes that many waters (marine, naturally
alkaline, or acidic fresh waters) cause eye irrita-
tion, the relation of pH to eye irritation justifies
inclusion of pH criteria to enhance recreation en-
joyment where pH can be controlled.
In the light of its coordinate effect, the buffering
capacity should be considered in criteria to prevent
eye irritation.
The lacrimal fluid of the human eye has a
normal pH of approximately 7.4 and a very high
buffering capacity, due primarily to the presence of
buffering agents of the complex organic type. As is
true of many organic buffering agents, those of the
lacrimal fluid are able to maintain the pH within
a very narrow range until their buffering capacity
is exhausted. When the lacrimal fluid, through
exhaustion of its buffering capacity, is unable to
adjust the immediate contact layer of a fluid to a
pH of 7.4, eye irritation results. A deviation of no
more than 0.1 unit from the normal pH of the eye
may result in discomfort. Appreciable deviation
will cause severe pain (see appendix at the end of
this section).
Recommendation: In primary contact recreation waters,
the pH should be within the range of 6.5-8.3 except
when due to natural causes and in no case shall be less
than 5.0 nor more than 9.0. When the pH is less than
6.5 or more than 8.3, discharge of substances which
would increase the buffering capacity of the water
should be limited.
There are additional criteria the Subcommittee
considers to be desirable but not mandatory.
Among these are criteria for clarity and tempera-
ture. Clarity in recreational waters is highly de-
sirable from the standpoint of visual appeal, recre-
ational enjoyment, and safety. Variation in natural
conditions makes it difficult to set absolute criteria
for this factor. However, turbidity attributable to
human activity should be controlled in recreation
waters where feasible in the light of natural con-
ditions.
Recommendation: For primary contact recreation
waters,. clarity should be such that a Secchi disc is
visible at a minimum depth of 4 feet. In "learn to
swim" areas the clarity should be such that a Secchi
disc on the bottom is visible. In diving areas the clarity
shall equal the minimum required by safety standards,
depending on the height of the diving platform or
board.
The Subcommittee is cognizant that recommen-
dations on clarity may have more value for plan-
ners of primary recreation areas than for water
quality administrators.
Temperature is another factor which may be
important to recreation enjoyment. In some locali-
ties and at certain times, elevation of temperature
may be desirable (to lengthen a recreation season,
for instance), but in most cases total recreation
values (including particularly recreational fish-
ing) are more likely to be reduced than enlarged
by excessive temperature elevation. Except in
cases where temperature elevations for primary
contact recreation are justified, the Subcommittee
suggests a stringent restriction on permissible
temperature rises.
Excessively high temperatures may lessen the
pleasure of some water contact sports, as well as
be damaging to biota. Moreover, high tempera-
tures limit the dissipation of body heat and may,
through elevation of the deep body temperature,
produce serious physiological disturbances. It has
been determined that a person swimming expends
energy at the rate of approximately 500 calories
per hour. This is about five times the rate when
sitting still and about twice the rate when walking.
This energy must be dissipated to the environment
to avoid a rise in the deep body temperature. When
conduction is the principal means of heat transfer
from the body and exposure to the environmental
conditions is prolonged, 32.2 C (90 F) is the ap-
proximate limit for persons expending minimal
energy. Since most swimmers utilize energy at a
moderate rate, the maximum water temperature
that will not induce undesirable physiological ef-
fects after prolonged exposure must be less than
32.2 C (90 F). Experience with military person-
nel exposed to warm water continously for several
hours indicates that 30C (85F) is a safe maxi-
mum limit.
Limited exposure to water warmer than 30 C
(85 F) can be tolerated for short periods of time
without causing undesirable physiological effects.
In fact, some people get particular enjoyment from
bathing in water from hot springs. However, these
are special circumstances and persons bathing in
such water usually limit their exposure to short
periods of time and do not engage in moderate
exercise such as swimming for prolonged periods.
13
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Recommendation: In primary contact recreation waters,
except where caused by natural conditions, maximum
water temperature should not exceed 30 C (85 F).
Other aspects of water quality for the primary
contact recreation user, including those associated
with mental satisfaction rather than health or
physical well-being, can be met by adherence to
recommendations for realization of aesthetic val-
ues and enhancement of recreation enjoyment.
a single set of criteria for recreation in fresh, estua-
rine, and marine waters. Given the lack of defini-
tive data, reasonable latitude for criteria in marine
waters should be provided in specific instances
where acceptable monitoring and observation sup-
port other criteria.
Recreation criteria for marine waters
The Subcommittee has considered the advis-
ability of establishing separate criteria for marine
and estuarine waters. While some studies would
seem to indicate that nothing short of actual inges-
tion of paniculate fecal matter constitutes a threat
to the recreation user in marine waters, the Sub-
committee does not feel that information now
available justifies separate criteria.
Several additional arguments favoring more
lenient microbiological criteria in marine waters
have been advanced, but upon careful considera-
tion these have been rejected by the Subcommittee
as not being sufficient justification for relaxation of
the criteria.
It is frequently stated that salt water is less
palatable than fresh water and when accidentally
taken into the mouth is ejected rather than in-
gested, thus materially lessening the chance of
intake of water-borne pathogens. However, salt
water is not so unpalatable that it is automatically
ejected. This is particularly true in the case of
children where the sophistications of adults have
not developed.
Another argument posed in favor of the lessened
threat of pathogens from fecal contamination in
marine waters is the bactericidal properties of
these waters. However, the bactericidal properties
of marine waters are weak; their effectiveness in
providing a safety factor is questionable. More-
over, if marine waters were bactericidal, the
presence of indicator organisms would indicate
very recent fecal contamination, which, in the
absence of demonstrated selective bactericidal ef-
fect on pathogens, might suggest a greater threat
to health than comparable concentrations of indi-
cator organisms in fresh water. One might cite the
outbreaks of infectious hepatitis traced to marine
sources as a further refutation of the protection
afforded by bactericidal properties of marine
waters.
In view of the foregoing, the Subcommittee
would suggest, as a general practice, application of
selected bibliography
BUREAU OF OUTDOOR RECREATION. 1967. Superin-
tendent of Documents, U.S. Government Printing
Office, Washington, D.C.
COETZE, O. J. 1961. Comments on sewage contamina-
tion of coastal bathing waters. South African Med. J.
35: 261.
COMMITTEE ON SCIENCE AND ASTRONAUTICS, SUBCOM-
MITTEE ON SCIENCE, RESEARCH, AND DEVELOPMENT.
1966. U.S. House of Representatives, 89th Cong., 2nd
sess.
GELDREICH, E. E. 1966. Sanitary significance of fecal
coliforms in the environment. U.S. Department of the
Interior, Federal Water Pollution Control Administra-
tion. WPC Res. Ser. Pub. No. WP-20-3.
MOORE, B. 1959. Sewage contamination of coastal
bathing waters in England and Wales. A bacteriologi-
cal and epidemiological study. J. Hyg. 57(4): 435.
OUTDOOR RECREATION RESOURCES REVIEW COMMITTEE.
1962. Outdoor recreation for America. Superin-
tendent of Documents, U.S. Government Printing
Office, Washington, D.C.
PUBLIC HEALTH ACTIVITIES COMMITTEE, SANITARY
ENGINEERING DIVISION. 1963. Coliform standards for
recreational waters. Amer. Soc. Civil Engr., Proc.
57-94.
SMITH, R. S., T. D. WOOLSEY, AND A. H. STEVENSON.
1961. Bathing water quality and health, I. Great
Lakes. U.S. Public Health Service, Environmental
Health Center, Cincinnati, Ohio.
SMITH, R. S., AND T. D. WOOLSEY. 1952. Bathing water
quality and health, II. Inland river. Environmental
Health Center, Cincinnati, Ohio.
SMITH, R. S., ET AL. 1961. Bathing water quality and
health, III. Coastal waters. Environmental Health
Center, Cincinnati, Ohio.
STEVENSON, A. H. 1953. Studies of bathing water
quality. Amer. J. Pub. Health 43(5): 529.
14
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appendix
The role of some physico-chemical
properties of water as causative
agents of eye irritation of swimmers
by Eric W. Mood, M.P.H.
An important consideration of the physico-
chemical characteristics of water used for recrea-
tion purposes involves those properties that may
cause eye irritation to bathers and swimmers.
Water is a foreign environment to the human eye.
Under certain conditions, water may be very irri-
tating to the eyes of most swimmers and bathers,
but under other conditions it may be non-irritating
to all but a few.
Some knowledge about the characteristics of
water that generally is irritating to the eyes of
swimmers has been developed through research
efforts of ophthalmologists and others, many of
whom were interested in the preparation of oph-
thalmic solutions. These researchers assumed that
an ideal non-irritating solution would have similar
physico-chemical properties as tears. Therefore,
studies were undertaken initially to determine the
chemical composition of lacrimal fluid, particularly
of the following: (1) hydrogen-ion concentration
orpH, (2) buffer capacity, and (3) tonicity.
Early studies of the hydrogen-ion concentration
of tears developed values ranging from 6.3 to 8.6.
Diligent efforts by Hind and Goyan (1,2) yielded
more precise data. They found that lacrimal fluid
has a pH of approximately 7.4. This result is not
unexpected as the pH of human blood normally is
found to range from 7.4 to 7.5.
Correlated with the hydrogen-ion concentration
is buffer capacity of the fluid. A solution of low
buffer capacity can have its pH level changed
easily, but a solution with a high buffer capacity
may not have the hydrogen-ion concentration
easily or appreciably altered. Analyses for the
chemical constituents of tears denoted the presence
of carbonic acid, weak organic acids and proteins
(3). These elements allow lacrimal fluid to neu-
tralize both weakly acidic and weakly basic solu-
tions to the approximate pH of the lacrimal fluid.
It has been demonstrated that tears have the ca-
pacity to bring the pH of an unbuffered solution
from as low as 3.5 or as high as 10.5, to within
tolerable limits in a very short time (3).
If the chemical constituents of the solution in
contact with the eye are such as to resist the buf-
fering action of the lacrimal fluid and the pH of the
solution in direct contact with the eye is 0.1 or
15
-------
more units of pH higher or lower than pH-7.4, a
pain response may be elicited.
In addition to the factors concerning hydrogen-
ion concentration and buffer capacity, the tonicity
of the fluid in contact with the eye is an important
consideration to minimize irritation or pain re-
sponse. Lacrimal fluid is isotonic (i.e., having the
same osmotic pressure) with blood and has a to-
nicity equivalent to that of a 0.9-percent sodium
chloride solution. Early studies by Hind and
Goyan (7) showed that a sodium chloride equiva-
lent range of 0.5 percent to 2.0 percent concentra-
tion was well tolerated. Later, Riegelmann,
Vaughan and Okumoto (5), and Riegelmann and
Vaughan (4) suggested that the range be nar-
rowed to the equivalence of between 0.7 percent
to 1.5 percent sodium chloride.
Tonicity of water used for recreation will be
important in reducing or preventing eye irritation
only in those cases where there is prolonged ex-
posure of the eye to water. The usual type of
recreational bathing and swimming which most
people engage in does not usually involve pro-
longed exposure of the eye to water. Hence, tonic-
ity of recreation waters is of much less importance
than the hydrogen-ion concentration and the buffer
capacity in preventing or reducing eye irritation to
bathers and swimmers.
An ideal water that would be non-irritating to
the majority of bathers would be one that is rela-
tively unbuffered and has a sodium chloride
equivalent of 0.9 percent and a pH of 7.4. Since
the ideal can seldom, if ever, be achieved, alter-
nate values are necessary. While the lacrimal fluid
can adjust the pH of an unbuffered solution from
as low as 3.5 or as high as 10.5 to within tolerable
limits within a short time, these limits of pH have
no practical value as unbuffered water is not
found in nature under usual conditions. Almost
all natural waters have some buffer capacity.
Therefore, to minimize eye irritation to bathers, it
seems desirable to suggest that for natural waters
with low buffer capacity, the pH range be between
5.0 and 9.0. Since most natural waters have more
than a low buffer capacity, a more desirable range
of pH would be 6.5 to 8.3.
In summary, when water quality standards are
proposed for swimming, bathing, and other similar
uses, consideration should be given to those
physico-chemical properties that may cause or
contribute to eye irritation. Of principal impor-
tance is the hydrogen-ion concentration with code-
pendence upon the buffer capacity of the water.
Ideally, the pH of water should be approximately
the same as the pH of lacrimal fluid which is about
7.4 for most people. Since the lacrimal fluid has a
high buffering capacity, a range of pH values from
6.5 to 8.3 can be tolerated under average condi-
tions. If the recreation water is relatively free of
dissolved solids and has a very low buffer capacity,
pH values from 5.0 to 9.0 should be acceptable.
However, for recreation water having a pH less
than 6.5 or greater than 8.3, waste discharge
standards should include prohibition against re-
leases that will increase the buffer capacity of the
receiving waters and yet maintain the pH below
6.5 or greater than 8.3. Tonicity standards do not
seem to have any practical value.
references
(7) HIND, H. W., AND F. M. GOYAN. 1947. A new
concept of the role of hydrogen-ion concentration
and buffer systems in the preparation of ophthalmic
solutions. J. Am. Pharm. Assoc. (Sci. Ed.), 36: 33-
41.
(2) HIND, H. W., AND F. M. GOYAN. 1949. The hydro-
gen-ion concentration and osmotic properties of
lacrimal fluid. J. Am. Pharm. Assoc. (Sci. Ed.),
38: 477-479.
(3) JOHNSON, R. D. Role of tonicity, pH, and buffers as
they apply to pharmaceutical development of
ophthalmic preparations (unpublished article).
(4) RIEGELMANN, S., AND D. G. VAUGHAN, JR. 1958.
A rational basis for the preparation of ophthalmic
solutions. Part 1. J. Am. Pharm. Assoc. (Prac.
Pharm. Ed.), 19: 474-477.
(5) RIEGELMANN, S., D. G. VAUGHAN, JR., AND M.
OKUMOTO. 1955. Compounding ophthalmic solu-
tions. J. Am. Pharm. Assoc. (Prac. Pharm. Ed.),
16: 742-746.
16
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Section II
public water supplies
-------
introduction
THE NATIONAL Technical Advisory Sub-
committee on Public Water Supplies has
found it necessary to make some rather arbitrary
decisions in order to proceed with its task of de-
veloping raw water quality criteria for public water
supplies. Because public water supplies commonly
involve processing of the raw water to improve its
quality before distributing it to consumers, and
because treatment processes exist which can, at a
price, convert almost any water including sea
water and grossly polluted fresh water into a pot-
able product, it is necessary to consider the type
of treatment in any discussion of raw water quality
criteria for public water supplies.
We have adopted as the considered treatment
the most common processes in use in this country
in their simplest form for the treatment of surface
waters for public use. This may include coagula-
tion (less than about 50 ppm alum, ferric sulfate,
or copperas with alkali addition as necessary but
without coagulant aids or activated carbon), sedi-
mentation (6 hours or less), rapid sand filtration
(3 gal/sq ft/min or less) and disinfection with
chlorine (without consideration to concentration
or form of chlorine residual). A wide variety of
modifications of this basic treatment process are in
use for removing various impurities or altering
quality characteristics, but we have arbitrarily
excluded these modifications in our deliberations
because of the difficulty in deciding where to stop
in considering the many modifications and elabora-
tions of the basic process.
Definitions
We have listed two types of criteria defined as
follows:
(a) Permissible criteria.—Those character-
istics and concentrations of substances in
raw surface waters which will allow the
production of a safe, clear, potable, aes-
thetically pleasing, and acceptable public
water supply which meets the limits of
Drinking Water Standards (10) after
treatment. This treatment may include,
but will not include more than, the proc-
esses described above.
(b) Desirable criteria.—Those characteristics
and concentrations of substances in the
raw surface waters which represent high-
quality water in all respects for use as pub-
lic water supplies. Water meeting these
criteria can be treated in the defined plants
with greater factors of safety or at less cost
than is possible with waters meeting per-
missible criteria.
Several words used in the table and in the text
require explanation in order to convey the Sub-
committee's intent:
Narrative.—The presence of this word in the
table indicates that the Subcommittee could not
arrive at a single numerical value which would be
applicable throughout the country for all condi-
tions. Where this word appears, the reader is
directed to the appropriate explanatory text.
Absent.—The most sensitive analytical pro-
cedure in Standard Methods (9) (or other ap-
proved procedure) does not show the presence of
the subject constituent.
Virtually absent.—This terminology implies
that the substance is present in very low concen-
trations and is used where the substance is not
objectionable in these barely detectable concen-
trations.
18
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discussion
treating such supplies. This is the importance of
the factors of safety mentioned in the definition of
"desirable criteria". However, managers of all sup-
plies would welcome improved raw water quality.
This Subcommittee believes that the criteria set
forth herein can be used in setting standards of
raw water quality only with a substantial amount
of understanding and discretion. To a considerable
extent this is related to the very great regional
variations in water quality entirely aside from
manmade pollution. In addition, human oc-
cupance and activity have inevitable effects on
water quality. These facts make it difficult and
sometimes impossible to develop uniform numeri-
cal criteria suitable for national application.
The criteria selected by the Subcommittee are
listed in the table and discussed in the numbered
paragraphs cited in the table. The paragraphs also
include some rationale of the basis for the criteria.
The fact that a substance is not included in these
criteria does not imply that its presence is innocu-
ous. It would be quite impracticable to prepare a
compendium of all toxic, deleterious, or otherwise
unwelcome agents that may enter a surface water
supply.
Sampling
THE SUBCOMMITTEE recognizes that sur-
face waters are used for public water supply
without treatment other than disinfection. Such
waters at the point of withdrawal should meet
Drinking Water Standards (JO) in all respects
other than bacterial quality.
It should be emphasized that many raw water
sources which do not meet these permissible cri-
teria have been and are being used to provide satis-
factory public water supplies by suitable additions
to and elaboration of the treatment processes de-
fined above. In some instances, however, the water
delivered to the customer is of marginal quality.
Also the finished water is much more likely to be-
come unsatisfactory if treatment plant irregularities
occur. It is recognized that most of the surface
water treatment plants providing water for do-
mestic use in the United States are relatively small
(7) and without sophisticated technical controls.
Marginal quality characteristics, therefore, assume
considerable importance to the managers of plants
Sampling should be of such frequency and of
such variety (time of day, season, temperature,
river stage or flow, location, depth) as to properly
describe the body of water designated for public
water supply. Sampling should also be conducted
in full cognizance of findings of the sanitary sur-
very. Judgment should be exercised as to the rela-
tive desirability of frequent sampling at one point,
such as the raw water intake, as compared to less
frequent sampling at numerous locations, such as
is required for stream profiles or cross sections.
It is clearly not possible to apply these criteria
solely as maximum single sample values. The cri-
teria should not be exceeded over substantial por-
tions of time. If they are exceeded, efforts should
be made to determine the cause, and corrective
measures undertaken.
The criteria are based upon those analytical
methods described in Standard Methods for the
Examination of Water and Wastewater (9) or
upon methods acceptable to water pollution con-
trol agencies.
19
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TABLE ll-l. Surface Water Criteria for Public Water Supplies
Permissible Desirable
Constituent or characteristic criteria criteria Paragraph
Physical:
Color (color units) 75 <10 .1
Odor Narrative Virtually absent 2
Temperature * do Narrative 3
Turbidity do Virtually absent 4
Microbiological:
Coliform organisms 10,000/100 ml1 <100/100 ml1 5
Fecal coliforms 2,000/100 ml1 <20/100 mlJ 5
Inorganic chemicals: (mg/l) (mg/l)
Alkalinity Narrative Narrative 6
Ammonia 0.5 (as N) <0.01 7
Arsenic * 0.05 Absent 8
Barium * 1.0 do 8
Boron * 1.0 do 9
Cadmium * 0.01 do 8
Chloride * 250 <25 8
Chromium,* hexavalent 0.05 Absent 8
Copper * 1.0 Virtually absent 8
Dissolved oxygen >4 (monthly mean) Near saturation 10
>3 (individual sample)
Fluoride * Narrative Narrative 11
Hardness * ._. do do 12
Iron (filterable) 0.3 Virtually absent 8
Lead * 0.05 Absent 8
Manganese* (filterable) 0.05 do 8
Nitrates plus nitrites* 10 (as N) Virtually absent 13
pH (range) 6.0-8.5 Narrative 14
Phosphorus * Narrative do 15
Selenium * 0.01 Absent 8
Silver* 0.05 do 8
Sulfate * 250 <50 8
Total dissolved solids* 500 <200 16
(filterable residue).
Uranyl ion * 5 Absent 17
Zinc * 5 Virtually absent 8
Organic chemicals:
Carbon chloroform extract* (CCE) 0.15 <0.04 18
Cyanide * 0.20 Absent 8
Methylene blue active substances * 0.5 Virtually absent 19
Oil and grease * Virtually absent Absent 20
Pesticides:
Aldrin * 0.017 do 21
Chlordane * 0.003 do 21
DDT* 0.042 do 21
Dieldrin * 0.017 do 21
Endrin * 0.001 do 21
Heptachlor * 0.018 do 21
Heptachlor epoxide * 0.018 do 21
! indane * 0.056 do 21
,/lethoxychlor * 0.035 do 21
Organic phosphates plus O.I2 do 21
carbamates.*
Toxaphene * 0.005 do 8
Herbicides:
2,4-D plus 2,4,5-T, plus 2,4,5-TP * 0.1 do 21
Phenols * 0.001 do 8
Radioactivity: (pc/i) (pc/i)
Gross beta* 1,000 <100 8
Radium-226 * 3 <1 8
Strontium-90 * 10 <2 8
* The defined treatment process has little effect on this limit may be relaxed if fecal coliform concentration does not
constituent. exceed the specified limit.
1 Microbiological limits are monthly arithmetic averages 2 As parathion in cholinesterase inhibition. It may be neces-
based upon an adequate number of samples. Total coliform sary to resort to even lower concentrations for some com-
pounds or mixtures. See par. 21.
20
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Paragraph 1: Color
A limit of 75 color units (platinum-cobalt
standard) has been recommended to permit the
defined plant to produce water meeting Drinking
Water Standards (10) with moderate dosages of
coagulant chemicals. At optimum pH the dosage
usually required is linearly related to the color of
the raw water, and higher color of the type com-
monly associated with swamp drainage and similar
nonindustrial sources can be removed by increas-
ing the coagulant dose. These criteria do not apply
to colors resulting from dyes and some other in-
dustrial and processing sources which cannot be
measured by the platinum-cobalt standard. Such
colors should not be present in concentrations
which cannot be removed by the defined method
of treatment.
Paragraph 2: Odor
The effectiveness of the defined method of treat-
ment in removing odorous materials from water is
highly variable depending on the nature of the
material causing the odor. For this reason, it has
not been feasible to specify any permissible cri-
terion in terms of threshold odor number. The raw
water should not have objectionable odor. Any
odors present should be removable by the defined
treatment. It is desirable that odor be virtually
absent.
Paragraph 3: Temperature
Surface water temperatures vary with geo-
graphical location and climatic conditions. Conse-
quently no fixed criteria are feasible. However,
any of the following conditions are considered to
detract (sometimes seriously) from raw water
quality for public water supply use:
(1) Water temperature higher than 85 F;
(2) More than 5 F water temperature increase
in excess of that caused by ambient con-
ditions;
(3) More than 1 F hourly temperature varia-
tion over that caused by ambient condi-
tions;
(4) Any water temperature change which ad-
versely affects the biota, taste, and odor, or
the chemistry of the water;
(5) Any water temperature variation or change
which adversely affects water treatment
plant operation (for example, speed of
chemical reactions, sedimentation basin
hydraulics, filter wash water requirements,
etc.);
(6) Any water temperature change that de-
creases the acceptance of the water for
cooling and drinking purposes.
Paragraph 4: Turbidity
Turbidity in water must be readily removable by
coagulation, sedimentation, and filtration; must
not be present in quantities (either by weight or
volume) that will overload the water treatment
plant facilities; and must not cause unreasonable
treatment costs. In addition, turbidity in water
must not be frequently changing and varying in
characteristics or in quantity to the extent that
such changes cause upset in water treatment plant
processing.
Customary methods for measuring and report-
ing turbidity do not adequately measure those
characteristics harmful to public water supply and
water treatment processing. A water with 30 Jack-
son turbidity units may coagulate more rapidly
than one with 5 or 10 units. Similarly water with
30 Jackson turbidity units sometimes may be more
difficult to coagulate than- water with 100 units.
Sometimes clay added to very low turbidity water
will improve coagulation. Therefore, it has not
been possible to establish a turbidity criterion in
terms of Jackson turbidity units. Neither can a
turbidity criterion be expressed in terms of mg/1
"undissolved solids" or "nonfilterable solids." The
type of plankton, clay, or earth particles, their size
and electrical charges, are far more determining
factors than the Jackson turbidity units. Neverthe-
less, it must be clearly recognized that too much
turbidity or frequently changing turbidity is
damaging to public water supply.
The criterion for too much turbidity in water
must relate to the capacity of the water treatment
plant to remove turbidity adequately and continu-
ously at reasonable cost. Water treatment plants
are designed to remove the kind and quantity of
turbidity to be expected in each water supply
source. Therefore, any increase in turbidity and
any fluctuating turbidity load over that normal to
a water must be considered in excess of that per-
missible.
Paragraph 5: Coliform and Fecal Coliform Or-
ganisms
Bacteria have been used as indicators of sani-
tary quality of water since 1880 when B. coli and
similar organisms were shown to be normal in-
habitants of fecal discharges. The coliform group
as presently recognized by Drinking Water Stand-
ards (10) is defined in Standard Methods for the
Examination of Water and Wastewater (9). This
group includes organisms that vary in Biochemical
and serologic characteristics and in their natural
sources and habitats; i.e., feces, soil, water, vege-
tation, etc.
Because the sanitary significance of the various
21
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members of the coliform group derives from their
natural sources, differentiation of fecal from non-
fecal organisms is important to evaluate raw water
quality (5). Fecal coliforms are characteristically
inhabitants of warmblooded animal intestines.
Members of other coliform subgroups may be
found in soil, on plants and insects, in old sewage,
and in waters polluted some time in the past.
The objective of using the coliform group as an
indicator of the sanitary quality of water is to eval-
uate the disease-producing potential of the water.
To estimate the probability of pathogens being
contributed from feces, the coliform and fecal
coliform content must be quantified.
In relation to raw water sources, the following
suggestions are offered to help resolve some of the
difficulties of data interpretation.
Fecal coliform organisms may be considered
indicators of recent fecal pollution. It is necessary
to consider all fecal coliform organisms as indica-
tive of dangerous contamination. Moreover, no
satisfactory method is currently available for dif-
ferentiating between fecal organisms of human and
animal origin.
In the absence of fecal coliform organisms, the
presence of other coliform group organisms may
be the result of less recent fecal pollution, soil run-
off water, or, infrequently, fecal pollution contain-
ing only those organisms.
In general, the presence of fecal coliform or-
ganisms indicates recent and possibly dangerous
pollution. The presence of other coliform orga-
nisms suggests less recent pollution or contribu-
tions from other sources of non-fecal origin.
In the past the coliform test has been the prin-
cipal criterion of suitability of raw water sources
for public water supply. The increase in chlorina-
tion of sewage treatment plant effluents distorts
this criterion by reducing coliform concentrations
without removing many other substances which the
defined water treatment plant is not well equipped
to remove. It is essential that raw water sources be
judged as to suitability by other measures and cri-
teria than coliform organism concentrations.
The defined water treatment plant is considered
capable of producing water meeting Drinking
Water Standards (10) bacteriological criteria from
these limits. The difference between the suggested
concentration of 10,000 coliforms per 100 ml and
the erstwhile figure of 5,000 per 100 ml is justified
by the difference between the Phelps Index and
the MPN. The Subcommittee suggests these num-
bers and the additional consideration of fecal coli-
forms in order to provide more realistic parame-
ters in full recognition of modern knowledge and
not as a means of sanctioning increased bacterial
pollution of waters destined for public water sup-
ply use.
Paragraph 6: Alkalinity
Alkalinity in water should be sufficient to
enable floe formation during coagulation, must not
be high enough to cause physiological distress in
humans, and must be proper for a chemically bal-
anced water (neither corrosive nor incrusting). A
criterion for minimum and maximum alkalinity in
public water supply is related to the relative
amounts of bicarbonates, carbonates, and hydrox-
ide ions causing the alkalinity; and also to the pH,
filterable (dissolved) solids, and calcium content.
Because the permissible criterion for filterable
solids is 500 mg/1 and the pH range is 6.0 to 8.5,
alkalinity should not be less than about 30 mg/1.
The criterion for maximum alkalinity cannot be
expressed in calcium carbonate equivalents as
determined from 0.02N H2SO4 titration because of
the interrelationships stated above. However, al-
kalinity values higher than about 400 mg/1 to
500 mg/1 would be too high for public water sup-
ply use. Within the range of 30 mg/1 to 500 mg/1,
the alkalinity criterion should be that value which
is normal to the natural water and which from
experience is satisfactory for public water supply
use. Frequent variations from normal values are
detrimental to public water supply processing
control.
Paragraph 7: Ammonia
Ammonia is a significant pollutant in raw water
for public water supplies because its reactions with
chlorine result in compounds with markedly less
disinfecting efficiency than free chlorine. In addi-
tion, it is frequently an indicator of recent sewage
pollution.
In the early days of waste treatment, the oxida-
tion of ammonia to nitrates was one of the major
objectives of waste treatment, but with the de-
velopment of the BOD test, this objective became
neglected. Greater attention to the design and
operation of waste treatment plants for the oxida-
tion of ammonia and organic nitrogen is needed to
minimize the concentration of pollution forms in
these receiving waters.
Paragraph 8: Arsenic, Barium, Cadmium,
Chromium (Hexavalent), Copper, Chloride, Cya-
nide, Iron, Lead, Manganese, Phenols, Selenium,
Silver, Sulfate, Zinc, and Radioactive Substances
The significance of these substances as con-
taminants of drinking water is discussed in Drink-
ing Water Standards (10). The permissible cri-
teria in this report are those included in Drinking
Water Standards. With the possible exception of
iron and in some instances copper and zinc, the
defined treatment plant does little or nothing to
remove these substances.
22
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Paragraph 9: Boron
Boron is found in the natural ground and sur-
face waters in some areas of the United States,
notably in the Western States where as much as
5 to 15 mg/1 are encountered. However, extensive
data on boron in both well and surface waters in
North America show that the amount of boron
normally encountered is less than 1 mg/1. The
ingestion of large amounts of boron can affect the
central nervous system and protracted ingestion
may result in a clinical syndrome known as
borism.
Boron is an essential element to plant growth
but is toxic to many plants at levels as low as
1 mg/1. The Public Health Service has established
a limit of 1 mg/1 which provides a good factor of
safety physiologically and also considers the do-
mestic use of water for home gardening.
Paragraph 10: Dissolved Oxygen
Criteria for dissolved oxygen are included, not
because the substance is of appreciable significance
in water treatment or in finished water, but because
of its use as an indicator of pollution by organic
wastes. It is intended for application to freeflowing
streams and not to lakes or reservoirs in which
supplies may be taken from below the thermocline.
Paragraph 11: Fluoride
The Subcommittee recognizes the potential
beneficial effects of fluoride ion in domestic water
supplies but recommends no "desirable" concen-
tration since any value less than that recommended
for the permissible limit would be acceptable from
the point of view of a water pollution control pro-
gram. Rapid fluctuations in raw-water fluoride ion
levels would create objectionable operating prob-
lems for communities supplementing raw-water
fluoride concentrations. The permissible criterion
is the upper limit of the recommended range in
Drinking Water Standards (10).
Annual average of Maximum daily air
, , i T- Recommended
temperatures F: Limi, mg/1
50.0 to 53.7 1.7
53.8 to 58.3 1.5
58.4 to 63.8 1.3
63.9 to 70.6 1.2
70.7 to 79.2 1.0
79.3 to 90.5 0.8
1 Based on temperature data obtained for a minimum
of 5 years.
Paragraph 12: Hardness
A singular criterion for the maximum hardness
in public water supply is not possible. Hardness in
water is largely the result of geological formations
with which the water comes in contact. Public ac-
ceptance of hardness varies from community to
community. Consumer sensitivity to objectionable
hardness is related to the hardness with which he
has become accustomed. Consumer acceptance of
hardness may also be tempered by economic
necessity.
Hardness should not be present in concentra-
tions that will cause excessive soap consumption,
or which will cause objectionable scale in heating
vessels and pipes. In addition, varying water hard-
ness is objectionable to both domestic and indus-
trial water consumers. With varying hardness, the
soap required for laundry, the effect on manu-
factured products, and the damage to process
equipment (such as boilers and cooling coils) can-
not be anticipated and compensated without facili-
ties which are not available to most water users. A
water hardness criterion must relate to the hard-
ness which is normal to the supply and exclude
hardness additions which will cause variations.
A criterion for objectionable hardness must be
tailored to fit the requirements of each community.
Hardness more than 300-500 mg/1 as CaCO3 is
excessive for public water supply. Many consum-
ers will object to water harder than 150 mg/1. In
other communities, the criterion for maximum wa-
ter hardness is considerably less than 150 mg/1. A
moderately hard water is sometimes defined as
having hardness between 60 to 120 mg/1.
Paragraph 13: Nitrate plus Nitrite
A limit of 10 mg/l(N) of nitrate ion plus nitrite
ion will be recommended by Drinking Water
Standards (70). Because the nitrite ion is the
substance actually responsible for causing methe-
moglobinemia, a combined limit on the two ions
is more significant than a limit on nitrates only.
Paragraph 14: pH
Most unpolluted waters have pH values within
the range recommended as a permissible criterion.
Any pH value within this range is acceptable for
public water supply. The further selection of a
specific pH value within this range as a desirable
criterion cannot be made.
Paragraph 15: Phosphorus
The Subcommittee has considered establishing
criteria on phosphorus concentrations but has not
been able to establish any generally acceptable
limit because of the complexity of the problem.
The purpose of such a limit would be twofold:
(a) To avoid problems associated with algae
and other aquatic plants, and
(b) To avoid coagulation problems due par-
ticularly to complex phosphates.
Phosphorus is an essential element for aquatic
life as well as for all forms of life and has been
considered the most readily controllable nutrient in
efforts to limit the development of objectionable
plant growths. Evidence indicates that high phos-
23
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phorus concentrations are associated with the
eutrophication of waters that is manifest in un-
pleasant algal or other aquatic plant growths when
other growth-promoting factors are favorable; that
aquatic plant problems develop in reservoirs or
other standing waters at phosphorus values lower
than those critical in flowing streams; that reser-
voirs and other standing waters will collect phos-
phates from influent streams and store a portion of
these within the consolidated sediments; that phos-
phorus concentrations critical to noxious plant
growths will vary with other water quality char-
acteristics, producing such growths in one geo-
graphical area but not in another.
Because the ratio of total phosphorus to that
form of phosphorus readily available for plant
growth is constantly changing and will range from
two to 17 times or greater, it is desirable to estab-
lish limits on the total phosphorus rather than the
portion that may be available for immediate plant
use. Most relatively uncontaminated lake districts
are known to have surface waters that contain 10
to 30 /ig/1 total phosphorus as P; in some waters
that are not obviously polluted, higher values may
occur (4). Data collected by the Federal Water
Pollution Control Administration, Division of Pol-
lution Surveillance, indicate that total phosphorus
concentrations exceeded 50 ^g/1 (P) at 48 percent
of the stations sampled across the Nation (6).
Some potable surface water supplies now exceed
200 ftg/1 (P) without experiencing notable prob-
lems due to aquatic growths. Fifty micrograms per
liter of total phosphorus (as P) would probably
restrict noxious aquatic plant growths in flowing
waters and in some standing waters. Some lakes,
however, would experience algal nuisances at and
below this level.
Critical phosphorus concentrations will vary
with other water quality characteristics. Turbidity
and other factors in many of the Nation's waters
negates the algal-producing effects of high phos-
phorus concentrations. When waters are detained
in a lake or reservoir, the resultant phosphorus
concentration is reduced to some extent over that
in influent streams by precipitation or uptake by
organisms and subsequent deposition in fecal pel-
lets or dead organism bodies. See the report of the
Subcommittee for Fish, Other Aquatic Life, and
Wildlife, and the section on Plant Nutrients and
Nuisance Organisms for a more complete dis-
cussion of phosphorus associations with the en-
richment problem.
At concentrations of complex phosphates of
the order of 100 /*g/l, difficulties with coagulation
are experienced.
Paragraph 16: Total Dissolved Solids (Filterable
Residue)
Drinking Water Standards (10) recommend
that total dissolved solids not exceed 500 mg/1
where other more suitable supplies are available.
It is noted, however, that some streams contain
total dissolved solids in excess of 500 mg/1. For
example, the Colorado River at the point of with-
drawal by the Metropolitan Water District of
Southern California has a total dissolved solids
concentration up to 700 mg/1.
High total dissolved solids are objectionable
because of physiological effects, mineral taste, or
economic effect. High concentrations of mineral
salts, particularly sulfates and chlorides, are asso-
ciated with corrosion damage in water systems.
Regarding taste, on the basis of limited research
work underway in California, limits somewhat
higher than 500 mg/1 are probably acceptable to
consumers of domestic water supplies. It is likely
that levels set with relation to economic effects are
controlling for this parameter.
Increases in total dissolved solids from those
normal to the natural stream are undesirable and
may be detrimental.
It is recommended that the permissible value
for total dissolved solids be set at 500 mg/1 in
view of the above evaluation. Further, it is recom-
mended that research work be sponsored to obtain
more information on total dissolved solids in
water relating to physiological effects, consumer
attitudes toward taste, and economic considera-
tions.
Paragraph 17: Uranyl Ion
The standard for uranyl ion (UO2=) is estab-
lished on the basis of its chemical properties rather
than on the basis of its being a radioactive mate-
rial. It is being added to Drinking Water Stand-
ards (10). Uranyl ion is of concern in drinking
water because of possible damage to the kidneys.
The threshold level of taste and the appearance of
color due to uranyl ion occur at about 10 mg/1
which is much less than the safe limit of ingestion
of this ion insofar as adverse physiological effects
are concerned.
The Public Health Service adopted the figure
of 5 mg/1 which is one-half the limit based on taste
and color and, therefore, there is a considerable
factor of safety in the adoption of 5 mg/1.
Paragraph 18: Carbon Chloroform Extract (CCE)
A limit of 0.2 mg/1 carbon chloroform extract
in drinking water is recommended in the Drinking
Water Standards "as a safeguard against the intru-
sion of excessive amounts of potentially toxic ma-
24
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terial into water" (10, 3). Although the analytical
procedure then in use leaves much to be desired
from the standpoint of simplicity, reproducibility,
and interpretation, it was the best available at that
time. The analytical procedure has been improved
since then and the newer technique (1,2) gives
substantially higher results than the one originally
used. The defined method of treatment generally
removes very little of the CCE present in the raw
water. In many instances there is an increase dur-
ing treatment. Whether this is real or apparent is
not known.
The permissible criterion of 0.15 mg/1 recom-
mended is based on use of the procedure cited in
Drinking Water Standards (10). We do not as
yet have sufficient information on which to base a
recommended limit using the lower flow rates and
sample volumes of the newer procedure. When this
information is available, a change in the criterion
is advisable. This limit is generally attainable
where vigorous efforts at pollution control are
carried out.
Paragraph 19: Methylene Blue Active Substances
This is an operationally more precise name for
substances discussed in Drinking Water Standards
(10) as alkyl benzene sulfonate. The permissible
criterion is the same as the limit recommended in
those standards. Those standards have been re-
vised to reflect this change in nomenclature.
Paragraph 20: Oil and Grease
It is very important that water for public water
supply be free of oil and grease. The difficulty of
obtaining representative samples of these mate-
rials from water makes it virtually impossible to
express criteria in numerical units. Since even very
small quantities of oil and grease may cause
troublesome taste and odor problems, the Sub-
committee desires that none of this material be
present in public water supplies. An additional
problem attributable to these agents is the un-
sightly scumlines on water treatment basin walls,
swimming pools, and other containers.
Paragraph 21: Pesticides and Herbicides
Consideration was given by the Subcommittee
to three groups of pesticides: the more common
chlorinated hydrocarbons, herbicides, and the
cholinesterase-inhibiting group which include the
organic phosphorus types and the carbamates. The
permissible levels are based upon recommenda-
tions of the Public Health Service Advisory
Committee on Use of the PHS Drinking Water
Standards. These values were derived for that Com-
mittee by an expert group of toxicologists as those
levels which, if ingested over extensive periods,
could not cause harmful or adverse physiological
changes in man. In the case of aldrin, heptachlor,
chlordane, and parathion, the Committee adopted
even lower than physiologically safe levels;
namely, amounts which, if present, can be detected
by their taste and odor. It should be noted that this
National Technical Advisory Subcommittee on
Public Water Supplies is not a group of lexico-
logical experts. Hence, the promulgation of addi-
tional criteria by the Public Health Service would
also be accommodated by this Subcommittee,
tempered—as was done above—by its experience
and judgment in the area of water treatment, as,
for example, in public acceptance of organoleptic
properties.
The limit for the cholinergic pesticides is estab-
lished relative to parathion and is expressed as
0.1 mg/1 parathion equivalent. This equivalence is
the ratio that a given pesticide of this group has to
parathion as unity in its cholinesterase inhibiting
properties. This makes it incumbent upon an ad-
ministrator of this limit to determine the pesticide
involved and to obtain expert toxicological opinion
on its parathion equivalence. Nearly all the or-
ganophosphorus compounds and the cholinergic
carbamates have high acute toxicity to mammals
and some have even higher toxicity to fish. Inges-
tion of small quantities of these compounds over
long time periods causes damage to mammalian
central nervous systems. Many organophosphorus
pesticides hydrolyze rapidly in the environment to
harmless or less harmful products. The hazards
from the chlorinated hydrocarbon pesticides in
water results from both direct effects, because they
tend to persist in their original form over long
periods, and indirect effects because they may be
concentrated biologically in man's food chain.
The values which were selected by the Public
Health Service as limits for this group of pesticides
are, however, set with substantial safety factors
insofar as they adversely affect the human body.
Generally, fish are more sensitive to this group of
pesticides and, therefore, may serve as a rough
method for determining when the chlorinated hy-
drocarbon pesticides content of water is approach-
ing a danger level. See the report of the Fish,
Other Aquatic Life, and Wildlife Subcommittee
for pesticide limits relative to maintaining healthy
and productive aquatic life.
It should be noted that limits for pesticides and
herbicides have been set with relation only to
human intake directly from a related domestic
water supply. The consequence of higher and pos-
sibly objectionable concentrations in fish available
to be eaten by man due to biological concentration
is considered not within the scope of the charge to
this Subcommittee.
25
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literature cited
(/) BOOTH, R. L., J. N. ENGLISH, AND G. N. Mc-
DERMOTT. 1965. Evaluation of sampling condi-
tions in the carbon adsorption method. J. Amer.
Water Works Assoc. 57: 215-220.
(2) BREIDENBACH, A. W., ET AL. 1966. The identifica-
tion and measurement of chlorinated hydrocarbon
pesticides in surface waters. WP-22, U.S. Depart-
ment of the Interior, Federal Water Pollution Con-
trol Administration, Washington, D.C.
(3) ETTINGER, M. B. 1960. A proposed toxicological
screening procedure for use in water works. J.
Amer. Water Works Assoc. 52: 689-694.
(4) GALES, M. F., JR., E. C. JULIAN, AND R. C. KRONER.
1966. Method for quantitative determination of
total phosphorus in water. J. Amer. Water Works
Assoc. 58: 1363-1368.
(5) GELDREICH, E. E. 1966. Sanitary significance of
fecal coliforms in the environment. U.S. Depart-
ment of Interior, Federal Water Pollution Control
Administration, Washington, D.C.
(6) GUNNERSON, C. B. 1966. An atlas of water pollu-
tion surveillance in the United States, Oct. 1, 1957,
to Sept. 30, 1965. Federal Water Pollution Con-
trol Administration, Cincinnati, Ohio.
(7) KOENIG, L. 1967. The cost of water treatment by
coagulation, sedimentation, and rapid sand filtra-
tion. J. Amer. Water Works Assoc. 59: 290-336.
(8) MIDDLETON, F. M., A. A. ROSEN, AND R. H.
BURTTSCHELL. 1962. Tentative method for car-
bon chloroform extract (CCE) in water. J. Amer.
Water Works Assoc. 54:223-227.
(9) STANDARD METHODS FOR THE EXAMINATION OF
WATER AND WASTEWATER. 1967. 12th ed. Amer.
Public Health Assoc. N.Y.
(10) U.S. DEPARTMENT OF HEALTH, EDUCATION, AND
WELFARE. 1962. Public Health Service drinking
water standards. PHS Pub. 956. Washington, D.C.
26
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Section III
fish, other aquatic life,
and wildlife
-------
letter
from the chairman
THE MEMBERSHIP of the National Techni-
cal Advisory Subcommittee on Water Quality
Criteria for Fish, Other Aquatic Life, and Wild-
life represents training and experience in several
phases of freshwater, marine and wildlife ecology.
physiology, and toxicology. The task of this Sub-
committee is to describe, insofar as possible, un-
der present knowledge: (1) the environmental
requirements of aquatic life and wildlife, (2) the
environmental concentrations of potential toxi-
cants that are not harmful under long-term ex-
posure, and (3) to suggest indirect methods for
determining safe concentrations through bioassays
and application factors. Because present know'-
edge of environmental requirements is incomplete
and information on safe concentrations of toxi-
cants is nonexistent for most organisms, tne recom-
mendations for water quality criteria of necessity
are incomplete, tentative, ana subject to change as
additional information becomes available. In the
determination of these criteria, the Subcommittee
has utilized the broad knowledge, the many years
of experience, and the understanding and com-
monsense of the Subcommittee members.
In order to expedite this task, the Subcommittee
was divided into three groups: one for freshwater
organisms; one for marine and estuarine orga-
nisms; and a third for wildlife.
Six task forces were set up in each of the first
two groups. Each of these task forces was assigned
certain environmental factors to review present
knowledge and determine environmental condi-
tions essential for the survival, growth, reproduc-
tion, general well-being, and production of a
desired crop of aquatic organisms. Members as-
signed to each task force were experts on that
particular subject or had wide experience with the
factors or materials in question. They were se-
lected with this in mind so that the whole subject
could be covered most effectively. The composite
report thus prepared was reviewed by the full
Subcommittee and approved on October 31 and
November 1, 1967, in Washington, D.C.
CLARENCE M. TARZWELL,
Chairman.
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introduction
DURING the course of geologic time, orga-
nisms which were able to adapt so they were
better fitted to live under existing environmental
conditions were the ones which survived and now
form the biota. Geologic change is a slow process
and biota developed which were adapted not only
to the physical and chemical but also to the bio-
logical factors of the environment. The environ-
mental factors to which organisms adapted through
the evolutionary process are now their environ-
mental requirements. Therefore, any relatively
rapid change in these conditions can be detri-
mental or even disastrous. Because the biota is the
result of long evolutionary processes during which
delicate balances were established, a change in
conditions or in a portion of the biota can have
far reaching effects.
Man has now attained the ability to alter
drastically his environment and that of other
organisms. Many of his activities already have im-
paired seriously his own environment and that of
other living things. Water pollution engineering
works and other changes that modify the aquatic
environment rank high in causing detrimental
effects.
Water pollutants may be harmful through alter-
ations in natural environmental conditions (such
as temperature, dissolved oxygen, pH, carbonates,
etc.), through physiological and other changes due
to the addition of toxicants, or through both. Thus,
in determining the effects of pollutants we must
consider environmental, physiological, and ac-
cumulative effects.
Substances in suspension and solution, whether
solid, liquid, or gas, largely determine the quality
of the water. Aquatic organisms are affected not
only directly by these materials, but also indirectly
through their effects on other forms of aquatic life
which comprise their food, competitors, and pred-
ators. Hence, the determination of water quality
requirements for aquatic life is a very involved
task. The problem is further complicated by the
fact that different species and different develop-
mental or life stages of the same or different
species may differ widely in their sensitivity or
tolerance to different materials, to ranges in en-
vironmental conditions, and to the cumulative
synergistic and antagonistic effects of toxicants.
In determining water quality requirements for
aquatic life and wildlife, it is essential to recognize
that there are not only acute and chronic toxic
levels but also tolerable, favorable, and essential
levels of dissolved materials. Lethal, tolerable, and
favorable levels and conditions may be ascertained
by: (1) determining the environmental factors and
concentrations of materials which are favorable in
29
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natural waters; (2) determining by laboratory
studies the relative sensitivity of organisms to
various environmental factors, and ranges which
are tolerable and favorable; (3) determining by
means of different bioassay studies the behavioral,
physiological, and other responses of organisms to
potential toxicants and concentrations of these
materials which are not harmful under continuous
exposure; and (4) testing laboratory findings in
the field to determine their adequacy for the pro-
tection of aquatic and wildlife resources.
In approaching this problem of protecting our
aquatic and wildlife resources, it must also be
realized that: (1) certain natural complexes of
dissolved materials to which aquatic organisms
have become adapted are favorable whereas other
concentrations or compositions may not be; (2)
unnatural materials added by man can be unfa-
vorable; (3) altering the amounts of substances
normally found in the environment can be harm-
ful; (4) toxicity is a quantitative term—any mate-
rial becomes toxic when its concentration exceeds
certain levels. It is essential, also, to realize that
requirements must be maintained throughout pe-
riods of low water, maximum discharge, maximum
temperature, minimum DO, variations in pH,
turbidity, salinity, etc. Further, it should be under-
stood that: (1) unfavorable conditions which may
be resisted for long periods by adults may be en-
tirely unfavorable for the survival of the species;
(2) conditions need to be unfavorable for only a
few hours to eliminate a population or group of
species; and (3) levels of environmental factors
and concentrations of toxicants that appear to
cause no harm during a few hours of exposure
may be intolerable for extended periods or for
recurring short-term exposures.
In defining water quality requirements for
aquatic life and wildlife, it is necessary to define
the extreme upper and lower limits of the various
environmental factors as well as the optimum
values. These extremes are outer limits and con-
stitute the minimum objectives to be obtained in
the improvement of waters for aquatic life. It is
not the intention of the Subcommittee that such
levels are to be considered as satisfactory. Fur-
ther, it is stressed that waters of higher quality
should not be degraded towards approximation of
the extremes. For example, the dissolved oxygen
content of water should be near saturation for best
production. The lower limits for oxygen indicated
in the report, therefore, represents the objective to
be obtained in the improvement of water, and not
the level to which good waters may be lowered.
It is essential that the various recommendations be
considered in context with the body of the report,
taking due consideration of the variability of local
conditions and native biota.
Within the United States there are great varia-
tions in environmental conditions and in the flora
and fauna. The environmental requirements of the
biota are different not only for different regions but
for different portions of the same region. Overlying
these differences are seasonal changes and daily
variations that have become essential factors in the
environment. Ideally, therefore, water quality cri-
teria for aquatic life and wildlife should take into
consideration local variations in requirements, sea-
sonal changes, and daily variations. They should
be national in scope. They should be applicable to
streams of various size and character, to all types
of lakes, to reservoirs, estuaries, and coastal
waters.
It is obvious that more research is needed on the
character, conditions, and interrelations in fresh
water, marine, and estuarine ecosystems which are
subjected to degradation or alteration as well as on
the physiological requirements and tolerances of
the various species involved in these different eco-
systems. This need must be satisfied for the estab-
lishing of sound criteria to maintain and preserve
aquatic resources and to permit the most economi-
cal and productive use of these resources by man.
Further, water quality requirements must be
expressed so as to allow for environmental modifi-
cations where such modifications are justifiable
and deemed to be in the public interest.
All these factors have been considered in de-
veloping the following recommended water quality
requirements for aquatic life.
It is the purpose of this document to define the
water quality requirements which must be met to
insure a favorable environment for fish, other
aquatic life, and wildlife. This report will do this
by identifying those aspects of water quality that
are most important in the light of current knowl-
edge and quantifying them where possible. Where
quantification is not yet possible, narrative guide-
lines will be offered. There is no doubt that the
water quality requirements contained herein must
be reviewed periodically and updated in the light
of additional and improved scientific data. The
recommendations given in this report are consid-
ered to be satisfactory for aquatic life. In all
instances where natural conditions fall outside the
recommended ranges, this environment may be
marginal and should not be changed in such a way
as to make it more unfavorable.
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zones of passage
AST BARRIER to migration and the free
movement of the aquatic biota can be
harmful in a number of ways. Such barriers block
the spawning migration of anadromous and cata-
dromus species. Many resident species make local
migrations for spawning and other purposes and
any barrier can be detrimental to their continued
existence. The natural tidal movement in estuaries
and downstream movement of planktonic orga-
nisms and of aquatic invertebrates in flowing fresh
waters are important factors in the re-population
of areas and the general economy of the water.
Any chemical or thermal barrier destroys this
valuable source of food and creates unfavorable
conditions below or above it.
It is essential that adequate passageways be pro-
vided at all times for the movement or drift of the
biota. Water quality criteria favorable to the
aquatic community must be maintained at all
times in these passageways. It is recognized, how-
ever, that certain areas of mixing are unavoidable.
These create harmfully polluted areas and for this
reason it is essential that they be limited in width
and length and be provided only for mixing. The
passage zone must provide favorable conditions
and must be in a continuous stretch bordered by
the same bank for a considerable distance to allow
safe and adequate passage up and down the
stream, reservoir, lake, or estuary for free-floating
and drift organisms.
The width of the zone and the volume of flow
in it will depend on the character and size of the
stream or estuary. Area, depth, and volume of flow
must be sufficient to provide a usable and desirable
passageway for fish and other aquatic organisms.
Further, the cross-sectional area and volume of
flow in the passageway will largely determine the
percentage of survival of drift organisms. There-
fore, the passageway should contain preferably
75 percent of the cross-sectional area and/or
volume of flow of the stream or estuary. It is
evident that where there are several mixing areas
close together they should all be on the same side
so the passageway is continuous. Concentrations
of waste materials in passageways should meet the
requirements for the water.
The shape and size of mixing areas will vary
with the location, size, character, and use of the
receiving water and should be established by
proper administrative authority. From the stand-
point of the welfare of the aquatic life resource,
however, such areas should be as small as possible
and be provided for mixing only. Mixing should be
accomplished as quickly as possible through the
use of devices which insure that the waste is mixed
with the allocated dilution water in the smallest
possible area. At the border of this area, the water
quality must meet the water quality requirements
for that area. If, upon complete mixing with the
available dilution water these requirements are not
met, the waste must be pretreated so they will be
met. For the protection of aquatic life resources,
mixing areas must not be used for, or considered
as, a substitute for waste treatment, or as an exten-
sion of, or substitute for, a waste treatment facility.
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summary
and key
criteria
RECOMMENDATIONS given below are con-
sidered to be satisfactory for aquatic life. In
all instances where natural conditions fall outside
the recommended ranges, these conditions may
be marginal and should not be changed in such a
way as to make them more unfavorable.
Freshwater organisms
Dissolved Materials
(1) Dissolved materials that are relatively in-
nocuous; i.e., their harmful effect is due to osmotic
effects at high concentrations, should not be in-
creased by more than one-third of the concentra-
tion that is characteristic of the natural condition
of the subject water. In no instance should the
concentration of total dissolved materials exceed
50 milliosmoles (the equivalent of 1500 mg/1
NaCl).
(2) Dissolved materials that are harmful in
relatively low concentrations are discussed in the
section "Toxicity."
pH, Alkalinity, Acidity
(1) No highly dissociated materials should be
added in quantities sufficient to lower the pH be-
low 6.0 or to raise the pH above 9.0.
(2) To protect the carbonate system and thus
the productivity of the water, acid should not be
added in sufficient quantity to lower the total al-
kalinity to less than 20 mg/1.
(3) The addition of weakly dissociated acids
and alkalies should be regulated in terms of their
own toxicities as established by bioassay pro-
cedures.
Temperature
Warm Water Biota: To maintain a well-
rounded population of warm-water fishes, the fol-
lowing restrictions on temperature extremes and
temperature increases are recommended:
(1) During any month of the year heat should
not be added to a stream in excess of the amount
that will raise the temperature of the water (at the
expected minimum daily flow for that month)
more than 5 F. In lakes, the temperature of the
epilimnion in those areas where important orga-
nisms are most likely to be adversely affected
should not be raised more than 3 F above that
which existed before the addition of heat of artifi-
cial origin. The increase should be based on the
monthly average of the maximum daily tempera-
ture. Unless a special study shows that a discharge
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of a heated effluent into the hypolimnion will be
desirable, such practice is not recommended and
water for cooling should not be pumped from the
hypolimnion to be discharged to the same body of
water.
(2) The normal daily and seasonal tempera-
ture variations that were present before the addi-
tion of heat due to other than natural causes
should be maintained.
(3) The recommended maximum temperatures
that are not to be exceeded for various species of
warm-water fish are given in table III-l.
Cold Water Biota: Because of the large number
of trout and salmon waters which have been de-
stroyed, made marginal, or nonproductive, remain-
ing trout and salmon waters must be protected if
this resource is to be preserved.
Inland trout streams, headwaters of salmon
streams, trout and salmon lakes, and the hypolim-
nion of lakes and reservoirs containing salmonids
and other cold water forms should not be warmed
or used for cooling water. No heated effluents
should be discharged in the vicinity of spawning
areas.
For other types and reaches of cold-water
streams, reservoirs and lakes, the following re-
strictions are recommended:
(1) During any month of the year heat should
not be added to a stream in excess of the amount
that will raise the temperature of the water more
than 5 F (based on the minimum expected flow for
that month). In lakes, the temperature of the
epilimnion should not be raised more than 3 F by
the addition of heat of artificial origin.
(2) The normal daily and seasonal temperature
fluctuations that existed before the addition of heat
due to other than natural causes should be main-
tained.
TABLE Ul-1
[Provisional maximum temperatures recommended as compati-
ble with the well-being of various soecies of fish and
their associated biota]
93 F: Growth of catfish, gar, white or yellow bass,
spotted bass, buffalo, carpsucker, threadfin shad,
and gizzard shad.
90 F: Growth of largemouth bass, drum, bluegill, and
crappie.
84 F: Growth of pike, perch, walleye, smallmouth bass,
and sauger.
80 F: Spawning and egg development of catfish,
buffalo, threadfin shad, and gizzard shad.
75 F: Spawning and egg development of largemouth
bass, white and yellow bass, and spotted bass.
68 F: Growth or migration routes of salmonids and for
egg development of perch and smallmouth bass.
55 F: Spawning and egg development of salmon and
trout (other than lake trout).
48 F: Spawning and egg development of lake trout,
walleye, northern pike, sauger, and Atlantic
salmon.
Note.—Recommended temperatures for other species, not
listed above, may be established if and when necessary in-
formation becomes available.
(3) The recommended maximum temperatures
that are not to be exceeded for various species of
cold-water fish are given in table III-l.
Dissolved Oxygen
The following environmental conditions are
considered essential for maintaining native popula-
tions of fish and other aquatic life.
(1) For a diversified warm-water biota, includ-
ing game fish, DO concentration should be above
5 mg/1, assuming normal seasonal and daily
variations are above this concentration. Under
extreme conditions, however, they may range be-
tween 5 and 4 mg/1 for short periods during any
24-hour period, provided that the water quality
is favorable in all other respects. In stratified
lakes, the DO requirements may not apply to the
hypolimnion. In shallow unstratified lakes, they
should apply to the entire circulation water mass.
These requirements should apply to all waters
except administratively established mixing zones.
In lakes, such zones must be restricted so as to
limit the effect on the biota. In streams, there must
be adequate and safe passageways for migrating
forms. These must be extensive enough so that the
majority of plankton and other drifting organisms
are protected (see section on zones of passage).
(2) For the cold-water biota, it is desirable that
DO concentrations be at or near saturation. This
is especially important in spawning areas where
DO levels must not be below 7 mg/1 at any time.
For good growth and the general well-being of
trout, salmon, and their associated biota, DO con-
centrations should not be below 6 mg/1. Under
extreme conditions, they may range between 6
and 5 mg/1 for short periods provided the water
quality is favorable in all other respects and nor-
mal daily and seasonal fluctuations occur. In large
streams that have some stratification or that serve
principally as migratory routes, DO levels may
range between 4 and 5 mg/1 for periods up to
6 hours, but should never be below 4 mg/1 at any
time or place.
(3) DO levels in the hypolimnion of oligo-
trophic small inland lakes and in large lakes should
not be lowered below 6 mg/1 at any time due to
the addition of oxygen-demanding waste or other
materials.
Carbon Dioxide
According to our present knowledge of the sub-
ject, it is recommended that the "free" carbon
dioxide concentration should not exceed 25 mg/1.
Oil
Oil or petrochemicals should not be added in
such quantities to the receiving waters that they
will—
33
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(1) produce a visible color film on the surface;
(2) impart an oily odor to the water or an oily
or other noxious taste to fish and edible in-
vertebrates;
(3) coat the banks and bottoms of the water
course or taint any of the associated biota;
(4) become effective toxicants according to the
criteria recommended in the "Toxicity"
section.
Turbidity
(1) Turbidity in the receiving waters due to the
discharge of wastes should not exceed 50 Jackson
units in warm-water streams or 10 Jackson units
in cold-water streams.
(2) There should be no discharge to warm-
water lakes which would cause turbidities exceed-
ing 25 Jackson units. The turbidity of cold-water
or oligotrophic lakes should not exceed 10 units.
Settleable Materials
Since it is known that even minor deposits of
settleable materials inhibit the growth of normal
stream and lake flora, no such materials should be
added to these waters in quantities that adversely
affect the natural biota.
Color and Transparency
For effective photosynthetic production of oxy-
gen, it is required that 10 percent of the incident
light reach the bottom of any desired photosynthe-
tic zone in which adequate dissolved oxygen con-
centrations are to be maintained.
Floating Materials
All floating materials of foreign origin should be
excluded from streams and lakes.
Tainting Substance
All materials that will impart odor or taste to
fish or edible invertebrates should be excluded
from receiving waters at levels that produce
tainting.
Radionuclides
(1) No radioactive materials should be pres-
ent in natural waters as a consequence of the fail-
ure of an installation to exercise appropriate con-
trols to minimize releases.
(2) No radionuclide or mixture of radionu-
clides should be present at concentrations greater
than those specified by the USPHS Drinking Water
Standards.
(3) The concentrations of radioactive mate-
rials present in fresh, estuarine, and marine waters
should be less than those that would require re-
strictions on the use of organisms harvested from
the area to meet the Radiation Protection Guides
recommended by the Federal Radiation Council.
Plant Nutrients and Nuisance Growths
The Subcommittee wishes to stress that the con-
centrations set forth are suggested solely as guide-
lines and the maintenance of these may or may not
prevent undesirable blooms. All the factors caus-
ing nuisance plant growth and the level of each
which should not be exceeded are not known.
(1) In order to limit nuisance growths, the
addition of all organic wastes such as sewage, food
processing, cannery, and industrial wastes contain-
ing nutrients, vitamins, trace elements, and growth
stimulants should be carefully controlled. Further-
more, it should be pointed out that the addition of
sulfates or manganese oxide to a lake should be
limited if iron is present in the hypolimnion as
they may increase the quantity of available
phosphorus.
(2) Nothing should be added that causes an in-
creased zone of anaerobic decomposition of a lake
or reservoir.
(3) The naturally occurring ratios and amounts
of nitrogen (particularly NO3 and NH4) to total
phosphorus should not be radically changed by the
addition of materials. As a guideline, the concen-
tration of total phosphorus should not be increased
to levels exceeding 100/tg/l in flowing streams or
50 ju.g/1 where streams enter lakes or reservoirs.
(4) Because of our present limited knowledge
of conditions promoting nuisance growth, we must
have a biological monitoring program to determine
the effectiveness of the control measures put into
operation. A monitoring program can detect in
their early stages the development of undesirable
changes in amounts and kinds of rooted aquatics
and the condition of algal growths. With periodic
monitoring, such undesirable trends can be de-
tected and corrected by more stringent regulation
of added organics.
Toxic Substances
(1) Substances of Unknown Toxicity: All efflu-
ents containing foreign materials should be con-
sidered harmful and not permissible until bioassay
tests have shown otherwise. It should be the obli-
gation of the agency producing the effluent to dem-
onstrate that it is harmless in the concentrations
to be found in the receiving waters. All bioassays
should be conducted strictly as recommended in
the body of this report and the appropriate appli-
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cation factor applied to determine the permissible
concentration of toxicant.
(2) Pesticides.
(a) Chlorinated hydrocarbons: Any addition
of chlorinated hydrocarbon insecticides is likely to
cause damage to some desired organisms and
should be avoided.
(b) Other chemical pesticides: Addition of
other kinds of chemicals used as pesticides and
herbicides can cause damage to desirable orga-
nisms and should be applied with utmost discretion
and caution. Table III-5 (p. 62) lists the 48-hour
TLm values of a number of pesticides for various
types of fresh water organisms. To provide rea-
sonably safe concentrations of these materials in
receiving waters, application factors ranging from
Vio to Moo should be used with these values
depending on the characteristic of the pesticide in
question and used as specified in (4), below.
Concentrations thus derived may be considered
tentatively safe under the conditions specified.
(3) Other Toxic Substances.
(a) ABS: Concentration of continuous expo-
sure to ABS should not exceed y7 of the 48-hour
TLm. A concentration as high as 1 mg/1 may be
tolerated occasionally for periods of time not ex-
ceeding 24 hours. ABS may increase the toxicity
of other materials.
(b) LAS: The concentration of LAS should
not exceed 0.2 mg/1 or % of the 48-hour TLm.
(4) Application Factors: Concentration of ma-
terials that are nonpersistant (that is, have a half-
life of less than 96 hours) or have noncumulative
effects after mixing with the receiving waters
should not exceed yln of the 96-hour TLm value
at any time or place. The 24-hour average of the
concentration of these materials should not exceed
14 <> of the TLm value after mixing. For other toxi-
cants the concentrations should not exceed y20
and Vtoo of the TLm value under the conditions
described above. Where specific application factors
have been determined, they will be used in all
instances.
(5) General Considerations. When two or more
toxic materials that have additive effects are pres-
ent at the same time in the receiving water, some
reduction is necessary in the permissible concen-
trations as derived from bioassays on individual
substances or wastes. The amount of reduction re-
quired is a function of both the number of toxic
materials present and their concentrations in re-
spect to the derived permissible concentration. An
appropriate means of assuring that the combined
amounts of the several substances do not exceed a
permissible concentration for the mixture is
through the use of following relationship:
a Lb Ln
Where C,,, Cb, . . . Cn are the measured concen-
trations of the several toxic materials in the water
and La, Lb, . . . Ln are the respective permissible
concentration limits derived for the materials on
an individual basis. Should the sum of the several
fractions exceed one, then a local restriction on
the concentration of one or more of the substances
is necessary.
Marine and estuarine organisms
Salinity
To protect estuarine organisms, no changes in
channels, basin geometry, or freshwater influx
should be made which would cause permanent
changes in isohaline patterns of more than 10 per-
cent of the naturally occurring variation.
Currents
Currents are important for transporting nutri-
ents, larvae, and sedimentary materials for flushing
and purifying wastes, and for maintaining patterns
of scour and fill. To protect these functions, there
should be no changes in basin geometry or fresh-
water inflow that will alter current patterns in such
a way as to adversely affect existing biological and
sedimentological situations.
PH
No materials that extend normal ranges of pH
at any location by more than 0.1 pH unit should
be introduced into salt water portions of tidal tribu-
taries or coastal waters. At no time should the in-
troduction of foreign materials cause the pH to be
less than 6.7 nor greater than 8.5.
Temperature
In view of the requirements for the well-being
and production of marine organisms, it is con-
cluded that the discharge of any heated waste into
any coastal or estuarine waters should be closely
managed. Monthly means of the maximum daily
temperatures recorded at the site in question and
before the addition of any heat of artificial origin
should not be raised by more than 4 F during the
fall, winter, and spring (September through May),
or by more than 1.5 F during the summer (June
through August), North of Long Island and in
the waters of the Pacific Northwest (north of
California), summer limits apply July through
September; and fall, winter, and spring limits ap-
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ply October through June. The rate of tempera-
ture change should not exceed 1 F per hour except
when due to natural phenomena.
Suggested temperatures are to prevail outside
of established mixing zones as discussed in the
section on zones of passage.
Dissolved Oxygen
Oxygen levels sufficient for the survival, growth,
reproduction, general well-being, and production
of a suitable crop must be maintained. The dis-
solved oxygen concentrations necessary to attain
this objective in coastal waters, estuaries, and tidal
tributaries are:
(1) Dissolved oxygen concentrations in surface
coastal waters should be greater than 5.0 mg/1
except when upwellings and other natural pheno-
mena may cause this value to be depressed.
(2) Dissolved oxygen concentration in estu-
aries and tidal tributaries should not be less than
4.0 mg/1 at any time or place except in naturally
dystrophic waters or where natural conditions
cause DO to be depressed.
Oil
No oil or petroleum products should be dis-
charged into estuarine or coastal waters in quanti-
ties that: (1) Can be detected as a visible film,
sheen, or by odor; (2) cause tainting of fish or
edible invertebrates; (3) form an oil sludge de-
posit on the shores or bottom of the receiving body
of water; (4) become effective toxicants according
to the criteria recommended in the "Toxicity"
section.
Turbidity
No effluent that may cause changes in turbidity
or color should be allowed to enter estuarine or
coastal waters unless it can be shown to have no
deleterious effects on the aquatic biota.
Settleable and Floating Substances
No materials that contain settleable solids or
substances that may precipitate out in quantities
that adversely affect the biota should be introduced
into coastal or estuarine waters. It is especially
urgent that areas which serve as habitat or nursery
grounds for commercially important species be
protected from any impairment of natural
conditions.
Tainting Substances
Substances that taint or produce off-flavors in
fish and edible invertebrates should not be pres-
ent in concentrations discernible by bioassay or
organoleptic tests.
Radionuclides
The recommendations made for freshwater or-
ganisms apply to marine and estuarine organisms.
Plant Nutrients and Nuisance Organisms
(1) No changes should be made in the basin
geometry, current structure, salinity, or tempera-
ture of the estuary until studies have shown that
these changes will not adversely affect the biota or
promote the increase of nuisance organisms.
(2) The artificial enrichment of the marine en-
vironment from all sources should not cause any
major quantitative or qualitative alteration in the
flora such as the production of persistant blooms
of phytoplankton (whether toxic or not), dense
growths of attached algae or higher aquatics, or
any other sort of nuisance that can be attributed
directly to nutrient excess or imbalance. Because
these nutrients often are derived largely from
drainage from land, special attention should be
given to correct land management in river basins
and shores of embayments to control unavoidable
erosion.
(3) The naturally occurring atomic ratio of
NO-i-N to PO4-P in a body of water should be
maintained. Similarly, the ratio of inorganic phos-
phorus (orthophosphate) to total phosphorus (the
sum of inorganic phosphorus, dissolved organic
phosphorus, and particulate phosphorus) should
be maintained as it occurs naturally. Nutrient im-
balances have been shown to cause a change in the
natural diversity of desirable organisms and to
reduce productivity.
Toxic Substances
(1) Substances of Unknown Toxicity: All efflu-
ents containing foreign materials should be con-
sidered harmful and not permissible until bioassay
tests have shown otherwise. It should be the obli-
gation of the agency producing the effluent to dem-
onstrate that it is harmless in the concentrations
that will be found in the receiving waters. All bio-
assays should be conducted strictly as recom-
mended in the body of this report and the appro-
priate application factor applied to determine the
permissible concentration of toxicant.
(2) Pesticides for Which Limits Have Been
Determined: The pesticides are grouped according
to their relative toxicity to shrimp. Criteria are
based on the best estimates in the light of present
knowledge and it is to be expected that acceptable
levels of toxic materials may be changed as a result
of future research.
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Pesticide group A.-—The following chemicals
are acutely toxic at concentrations of 5 /ig/1 and
less. On the assumption that Vioo of this level rep-
resents a reasonable application factor, it is rec-
ommended that environmental levels of these
substances not be permitted to rise above 50 nano-
grams/1. This level is so low that these pesticides
could not be applied directly in or near the marine
habitat without danger of causing damage. The 48-
hour TLm is listed for each chemical in jug/1.
Organochloride pesticides
Aldrin 0.04
BHC 2.0
Chlordane 2.0
Endrin 0.2
Heptachlor 0.2
Lindane 0.2
DDT 0.6
Dieldrin 0.3
Endosulfan 0.2
Methoxychlor 4.0
Perthane 3.0
TDE 3.0
Toxaphene 3.0
Organophosphorus pesticides
Coumaphos 2.0 Naled 3.0
Dursban 3.0
Fenthion 0.03
Parathion 1.0
Ronnel 5.0
Pesticide group B.—The following types of
pesticide compounds are generally not acutely
toxic at levels of 1.0 mg/1 or less. It is recom-
mended that an application factor of Vioo be used
and in the absence of acute toxicity data that an
environmental level of not more than 10 p.g/1
be permitted. An acute toxicity factor must be es-
tablished for each specific chemical in this group
to determine that it is not more toxic than related
compounds as indicated above:
Arsenicals
Botanicals
Carbamates
2,4-D compounds
2,4-,5-T compounds.
Phthalic acid compounds.
Triazine compounds.
Substituted urea compounds.
Other Pesticides.—Acute toxicity data are avail-
able for approximately 100 technical-grade pesti-
cides in general use not listed in the above groups.
These chemicals are either not likely to reach the
marine environment or, if used as directed by the
registered label, probably would not occur at levels
toxic to marine biota. It is presumed that criteria
established for these chemicals in fresh water will
protect adequately the marine habitat. It should
be emphasized that no unlisted chemical should
be discharged into the estuary without preliminary
bioassay tests.
(3) Industrial and Other Toxic Wastes.
(a) Safe concentrations of metals, ammonia,
cyanide, and sulfide should be determined by the
use of appropriate application factors to 96-hour
TLm values as determined by flow-through bioas-
says using dilution water that came from the re-
ceiving body. Test organisms should be local
species or life stages of organisms of economic
and ecologic importance which are the most sensi-
tive to the waste in question. Application factors
should be Vioo f°r metals, %0 f°r ammonia, Vio
for cyanide, and Vko f°r sulfide.
(b) Fluoride concentrations should not exceed
those for drinking water.
(c) Permissible levels of detergents in fresh
waters should also be applied to the marine and
estuarine waters.
(d) Bacteriological criteria of estuarine waters
utilized for shellfish cultivation and harvesting
should conform with the standards as described in
the National Shellfish Sanitation Program Manual
of Operation. These standards provide that—
(7) examinations shall be conducted in accord-
ance with the American Public Health Association
recommended procedures for the examination of
sea water and shellfish;
(2) there shall be no direct discharges of un-
treated sewage;
(3) samples of water for bacteriological exami-
nation to be collected under those conditions of
time and tide which produce maximum concentra-
tion of bacteria;
(4) the coliform median MPN of the water
does not exceed 70/100 ml, and not more than
10 percent of the samples ordinarily exceed an
MPN of 230/100 ml for a five-tube decimal dilu-
tion test (or 330/100 ml, where the three-tube
decimal dilution test is used) in those portions of
the area most probably exposed to fecal contami-
nation during the most unfavorable hydrographic
and pollution conditions;
(5) the reliability of nearby waste treatment
plants shall be considered in the approval of areas
for direct harvesting.
(e) Wastes from tar, gas, coke, petrochemical,
pulp and paper manufacturing, waterfront and
boating activities, hospitals, marine laboratories
and research installation wastes are all complex
mixtures having great variability in character and
toxicity. Due to this variability, safe levels must be
determined at frequent intervals by flow-through
bioassays of the individual effluents.
For those operations having persistent toxicants,
an application factor of Vioo should be used while
for those composed largely of unstable or biode-
gradable toxicants, an application factor of %o is
tentatively suggested.
(4) General Considerations.—When two or
more toxicants that have additive effects are pres-
ent, they must be treated as suggested earlier under
fresh water organisms.
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Wildlife
Dissolved Oxygen
In addition to the DO requirements for aquatic
organisms, the bottoms of areas used by wildfowl
must be kept aerobic to suppress botulinus
organisms.
Aquatic plants of greatest value as food for
waterfowl thrive best in waters with a summer pH
range of 7.0 to 9.2.
Alkalinity
Waterfowl habitats, to be productive, should
have a bicarbonate alkalinity between 30 and 130
mg/1. Fluctuations should be less than 50 mg/1
from natural conditions.
Salinity
Salinity should be kept as close to natural condi-
tions as possible. Fluctuations in salinity during
any 24-hour period should be limited as follows:
Natural salinity:
0 to 3.5%,
3.5 to 13.5&-
13.5 to 35.0#r-
Variation
permitted
Light Penetration
Optimum light requirements for aquatic wildlife
habitats should be at least 10 percent of incident
light at the surface to a 6-foot depth; the tolerable
limit should be 5 percent of the light at the surface
to the same depth.
Settleable Substances
Settleable substances destroy the usefulness of
aquatic bottoms for waterfowl. Settleable sub-
stances should be excluded from areas expected to
support waterfowl.
Oil
Oil is an especially dangerous substance to
waterfowl. Oil and petrochemicals must be ex-
cluded from both the surface and bottoms of any
area used by waterfowl.
Toxic Substances
Toxic substances should be excluded from
wildlife habitats to the degree that they affect the
health and well-being of wildlife, either directly or
through biological magnification. Special consid-
eration must be given to keep edible wildlife safe
for consumption by humans.
Disease
Offal from poultry houses, meatpacking plants,
as well as other possible sources of disease orga-
nisms, must be excluded from areas supporting
wildlife to guard against transmission of such dis-
eases as botulism, fowl cholera, and aspergillosis.
General
Water quality suitable for fish and other aquatic
organisms will be adequate for wildlife.
38
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Dissolved materials
fresh water
Water devoid of dissolved materials is intoler-
able in nature because pure water will not support
aquatic life. Natural waters contain endless varie-
ties of dissolved materials in concentrations that
differ widely from one locality to another as well
as from time to time. Many of these dissolved ma-
terials are essential for growth, reproduction, and
the general well-being of aquatic organisms. The
chlorides, carbonates, and silicates of sodium, po-
tassium, calcium, and magnesium are generally
the most common salts present. Traces of most
other essential substances are also found.
Aquatic organisms live in different concentra-
tions of dissolved substances but productivity de-
clines as the concentrations move away from the
optimum. Seldom, if ever, are the dissolved sub-
stances at the optimum concentrations as we know
them. The range of tolerance may be relatively
wide, but when the concentrations reach too low or
too high a level, organisms degenerate and die.
Different organisms vary in their optimum require-
ments as well as in their ability to live and thrive
under variations from the optimum. Some orga-
nisms are equally at home in sea water and in
fresh water. Other organisms will tolerate only one
or the other.
Any of the substances necessary to aquatic or-
ganisms has a range of concentration that is both
essential and tolerable. The tolerance levels for
any one substance vary depending on the concen-
trations of other substances present. The presence
of certain substances synergizes the effects of some
materials but antagonizes the effects of others.
Under optimal concentrations, the synergistic and
antagonistic effects are in balance and relatively
high concentrations can be tolerated without ad-
verse effects.
Although several measures of dissolved mate-
rials are available, no measure in itself is adequate
as an index of optimum concentration nor is any
single measure adequate to express the range of
tolerance. The biological effects depend on the
concentrations of the individual solutes, some of
which are tolerated in terms of grams per liter but
others only in nanograms per liter. Some exert con-
siderable osmotic pressure, but for others the
osmotic effect is negligible. Some substances con-
tribute greatly to conductivity, while others have
little or no effect.
In general, the concentrations of dissolved ma-
terials in natural fresh waters are below the opti-
mum for maximum productivity. In many in-
stances, therefore, the addition of any of a large
39
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number of substances will be beneficial. In this
way, many water courses have a capacity to ab-
sorb materials to advantage. But the addition of
what may be considered beneficial substances must
be controlled so that they will not exceed favorable
limits.
The osmotic concentration of the body'fluids of
a fresh water animal is generally the maximum
concentration of dissolved material that the ani-
mal will tolerate. In some animals, notably some of
the fresh water mollusks, the body fluids have an
osmotic concentration as low as 50 milliosmoles
(the equivalent of about 0.025 molar or 1,500
mg/1 sodium chloride). If the dissolved materials
are relatively innocuous, having only an osmotic
effect, it is judged that the total dissolved materials
in a water course may be increased to a certain
extent but they should not exceed 50 milliosmoles
if the fauna is to be maintained.
Many species of diatoms are very sensitive to
changes in chloride and other salt concentrations.
Some species, such as those in mountain streams
and in black water streams of the coastal plains,
can live only in waters with extremely low concen-
trations of salts. The addition of salts to such
streams will eliminate many desirable species of
diatoms and permit undesirable species to flourish.
Such changes may reduce the desirable food
sources and bring about nuisance problems as
well. It is believed that the total dissolved mate-
rial in a water course should not be increased by
more than one-third of that which is characteristic
of the natural conditions of such a water course.
The toxicity of substances added to natural
waters often depends on the substances already
present in the receiving waters. With synergism,
the toxicity increases, and with antagonism it de-
creases. Again the reaction of the toxic substances
may produce, in some cases, new products of
greater toxicity, and in others, products of lesser
toxicity.
In view of the many factors that become in-
volved in the disposal of soluble materials in na-
tural waters, it is evident that no simple answer is
available. Therefore, bioassays should be used to
determine the amounts of the materials that may
be tolerated without reducing the productivity of
the water course in question.
Recommendation: Dissolved materials are of two
types: those that are toxic at very low concentrations
and those, such as the salts of the earth metals, that
are required in certain concentrations for a productive
water and become harmful only at high concentrations
by exerting an osmotic effect. If the dissolved materials
are relatively innocuous, i.e., their harmful effect is an
osmotic one at high concentrations, it is judged that the
total dissolved materials of this type may be increased
to a certain extent but they should not exceed 50 mil-
liosmoles in waters where diversified animal popula-
tions are to be protected. Further, to maintain local
conditions, total dissolved materials should not be in-
creased by more than one-third of the concentration
that is characteristic of the natural condition of the
water. When dissolved materials are being increased,
bioassays and field studies should be used to determine
how much of the materials may be tolerated without
reducing the productivity of the desired organisms.
Acidity alkalinity, and pH
Acidity and alkalinity are reciprocal terms.
Acidity is produced by substances that yield hydro-
gen ions on hydrolysis and alkalinity is produced
by substances that yield hydroxyl ions. Other defi-
nitions state that a substance is acid if it will neu-
tralize hydroxyl ions and a substance is alkaline if
it will neutralize hydrogen ions. The terms "total
acidity" and "total alkalinity" are often used to
express the buffering capacity of a solution. Acidity
in natural waters is caused by carbon dioxide, min-
eral acids, weakly dissociated acids, and the salts
of strong acids and weak bases. Alkalinity is
caused by strong bases and the salts of strong
alkalies and weak acids.
An index of the hydrogen ion activity is pH.
Even though pH determinations are used as an
indication of acidity and/or alkalinity, pH is not a
measure of either. As pointed out in the first sen-
tence in the previous paragraph, acidity and al-
kalinity are reciprocal terms. Indeed, a water may
have both an acidity and alkalinity at the same
time. Total acidity, by definition, is the amount of
standard alkali required to bring a sample to pH
8.3. Total alkalinity, similarly, is the amount of
standard acid required to bring a sample to pH
4.5. Both are expressed in equivalents of CaCO,,.
Under these circumstances, there is a relation-
ship between pH, acidity, and alkalinity since, by
definition (see Standard Methods for the Exami-
nation of Water and Wastewater, 12th edition.
1965), any water with a pH of 4.5 or lower has no
measurable alkalinity and a water with a pH of
8.3 or higher has no measurable acidity.
In natural waters, where the pH is in the vicinity
of 8-3, acidity is not a factor of concern. In most
productive, fresh, natural waters, the pH falls in
the range between 6.5 and 8.5 (except when in-
creased by photosynthetic activity). Some aquatic
organisms have been found to live at pH 2 and
lower and others at pH 10 and higher; however,
such organisms are relatively few. Some natural
waters with a pH of 4 support fish and other or-
ganisms. In these cases the acidity is due primarily
to carbon dioxide and humic acids and the water
40
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has little buffering capacity (low total alkalinity).
Other natural waters with a pH of 9.5 also support
fish, but in such situations the waters are not
regarded as highly productive.
Acids that dissociate to a high degree do not
appear to be toxic at pH values above 6.0. They
are toxic if added in sufficient quantities to reduce
the pH to less than 6.0 Acids that dissociate to a
low degree are often toxic at pH values consider-
ably above 6.0. In the latter condition, toxicity is
due either to the anion or to the compound itself;
e.g., hydrogen cyanide (HCN), hydrogen sulfide
(H2S), and hypochlorous (HC1O) and tannic
acids.
Alkalies that dissociate to a high degree do not
appear to be toxic at pH values below 9.0. Alka-
line compounds that dissociate to a low degree are
often toxic at pH values less than 9.0 and their
toxicity is due either to the cation or to the undis-
sociated molecule. Ammonium hydroxide is an
example. Temporarily high pH levels often are
produced in highly productive waters through pho-
tosynthetic activity of the aquatic plants by con-
verting the carbonate to the hydroxide, which re-
sults in an increased pH. Because these high pH
levels prevail for only a few hours, they do not
produce the harmful effects of continuous high
levels due to the presence of strong alkalies.
Addition of either acids or alkalies to waters
may be harmful not only in producing adverse acid
or alkaline conditions, but also by increasing the
toxicity of various components in the waters. The
addition of strong acids may cause the formation
of carbonic acid (free CO2) in quantities that are
adverse to the well-being of the organisms present.
A reduction of about 1.5 pH units can cause a
thousand-fold increase in the acute toxicity of a
metallo-cyanide complex. The addition of strong
alkalies may cause the formation of undissociated
NH4OH or un-ionized NH3 in quantities that may
be toxic. The availability of many nutrient sub-
stances varies with the acidity and alkalinity. At
higher pH values, iron tends to become unavail-
able to some plants.
The nonlethal limits of pH are narrower for
some fish food organisms than they are for fish.
For example, Daphnia magna does not survive
experimentally in water having a pH below 6.0.
The major buffering system in natural waters is
the carbonate system. This system not only neutra-
lizes acids and bases so as to reduce the fluctua-
tions in pH, but also forms an indispensable reser-
voir of carbon for photosynthesis, because there is
a decided limit on the rate at which carbon dioxide
can be obtained from the atmosphere to replace
that in the water which becomes fixed by the
plants. Thus the productivities of waters are
closely correlated with the carbonate buffering
systems. The addition of mineral acids preempts
the carbonate buffering capacity and the original
biological productivity is reduced in proportion to
the degree that such capacity is exhausted. It is as
necessary, therefore, to maintain the minimum es-
sential buffering capacity as it is to confine the pH
of the water within tolerable limits.
Recommendation: (1) In view of the above con-
siderations and their importance for the production and
well-being of aquatic organisms, no highly dissociated
materials should be added in quantities sufficient to
lower the pH below 6.0 or to raise the pH above 9.0.
(2) To protect the carbonate system and thus the
productivity of the water, acid should not be added
sufficient to lower the total alkalinity below 20 mg/1
expressed as CaCO3.
(3) The addition of weakly dissociated acids and
alkalies should be regulated in terms of their own
toxicities as established by bioassay procedures.
Hardness
Hardness was originally considered as the
capacity of water to precipitate or neutralize soap.
In natural waters, hardness is chiefly attributable
to calcium and magnesium ions. Other ions, such
as strontium, barium, aluminum, manganese, iron,
copper, zinc, and lead also are responsible for
hardness, but since they are present in relatively
minor concentrations, their role usually can be
ignored. Hardness, like acidity and alkalinity, is
expressed in terms of CaCO3 but the hardness of
a water is not necessarily equal to either the acidity
or alkalinity. Hardness in natural waters is gener-
ally correlated with dissolved solids but there are
exceptions.
Generally, the biological productivity of a water
is directly correlated with its hardness, but hard-
ness per se has no biological significance because
productivity depends on the specific combination
of elements present. Calcium and magnesium con-
tribute to hardness and to productivity. Most other
elements that contribute to hardness reduce biolog-
ical productivity and are toxic when they produce
a substantial measure of hardness. Because hard-
ness of itself has no biological significance, and
because some elements which contribute to hard-
ness may enhance biological productivity (while
other contributing elements are toxic), it is rec-
ommended that the term hardness be avoided in
dealing with water quality requirements for aquatic
life.
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Temperature
The relationships of temperature and aquatic
life have been well studied. Extensive bibliogra-
phies and detailed surveys of the subject have been
published by the American Society of Civil Engi-
neers (1967), Brett (1960), Mihursky and Ken-
nedy (1967), Raney (1966), U.S. Department of
Interior, Federal Water Pollution Control Admin-
istration (1967), and Wurtz and Renn (1965).
The temperatures of the surface waters of the
United States vary from 32 to over 100 F as a
function of latitude, altitude, season, time of day,
duration of flow, depth, and many other variables.
The agents that may affect the natural temperature
are so numerous that it seems unlikely that two
bodies of water, even in the same latitude, would
have exactly the same thermal characteristics. The
fish and other aquatic life occurring naturally in
each body of water are species or varieties that are
competing there with various degrees of success
depending on the temperature and various other
conditions existing in that habitat. This adaptation
extends not only to temperature and the range over
which it can vary, but also to such factors as day
length and the other species of animals and plants
in the same habitat. The interrelationships of spe-
cies, day length, and water temperature are so inti-
mate that even a small change in temperature may
have far-reaching effects. An insect nymph in an
artificially warmed stream, for example, might
emerge for its mating flight too early in the spring
and be immobilized by the air temperature. Simi-
larly, a fish might hatch too early in the spring to
find an adequate amount of its natural food orga-
nisms because the food chain depends ultimately
on plants whose abundance in turn, is a function of
day length and temperature. The inhabitants of a
water body that seldom becomes warmer than 70 F
are placed under stress, if not killed outright, by
90 F water. Even at 75 to 80 F, they may be un-
able to compete successfully with organisms for
which 75 to 80 F is a favorable temperature. Simi-
larly, the inhabitants of warmer waters are at a
competitive disadvantage in cool water.
Although in a rigorous climate, an animal can
endure the extremes of temperature at appropriate
seasons; it must be cooled gradually in the fall if it
is to become acclimatized to the cold water of
winter and warmed gradually in the spring if it is to
withstand summer heat. Further, an organism
might be able to endure a high temperature of 92
or 95 F for a few hours, but it could not do so for
a period of days. Having the water change gradu-
ally with the season is important for other reasons:
an increasing or decreasing temperature often
serves as the trigger for spawning activities, meta-
morphosis, and migration. Some fresh water orga-
nisms require that their eggs be chilled before they
will hatch properly.
In arriving at suitable temperature criteria, the
problem is to estimate how far the natural tem-
perature may be exceeded without adverse effects.
Whatever requirements are suggested, a seasonal
cycle must be retained, the changes in temperature
must be gradual and the temperature reached must
not be so high or so low as to damage or alter the
composition of the desired population. In view of
the many variables, it seems obvious that no single
temperature requirement can be applied to the
United States as a whole, or even to one State; the
requirements must be closely related to each body
of water and its population. To do this a tempera-
ture increment based on the natural water tempera-
ture is more appropriate than an unvarying num-
ber. Using an increment requires, however, that
we have information on the natural temperature
conditions of the water in question, and the size of
the increment that can be tolerated by the desired
species.
If any appreciable heat load is introduced into a
stream, it must be recognized that the species'
equilibrium will likely be shifted towards that char-
acteristic of a more southerly water.
The seasonal temperature fluctuation normal to
the desired biota of a particular water must be
maintained. Further, the sum of any increase in
temperature plus the natural peak temperature
should be of short duration and below the maxi-
mum temperature that is detrimental for such
periods.
Recommendation for Warm Waters: To maintain a
well-rounded population of warm-water fishes, the fol-
lowing restrictions on temperature extremes and tem-
perature increases are recommended:
(1) During any month of the year, heat should not
be added to a stream in excess of the amount that will
raise the temperature of the water (at the expected
minimum daily flow for that month) more than 5 F.
In lakes and reservoirs, the temperatures of the epi-
limnion, in those areas where important organisms are
most likely to be adversely affected, should not be
raised more than 3 F above that which existed before
the addition of heat of artificial origin. The increase
should be based on the monthly average of the maxi-
mum daily temperature. Unless a special study shows
that a discharge of a heated effluent into the hypolim-
nion or pumping water from the hypolimnion (for dis-
charging back into the same water body) will be desir-
able, such practice is not recommended.
(2) The normal daily and seasonal temperature
variations that were present before the addition of heat,
due to other than natural causes, should be maintained.
(3) The recommended maximum temperatures that
are not to be exceeded for various species of warm-
water fish are given in table III-l.
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Recommendation for Cold Waters: Because of the
large number of trout and salmon waters which have
been destroyed, or made marginal or nonproductive,
the remaining trout and salmon waters must be pro-
tected if this resource is to be preserved:
(1) Inland trout streams, headwaters of salmon
streams, trout and salmon lakes and reservoirs, and the
hypolimnion of lakes and reservoirs containing sal-
monids should not be warmed. No heated effluents
should be discharged in the vicinity of spawning areas.
For other types and reaches of cold-water streams,
reservoirs, and lakes, the following restrictions are
recommended.
(2) During any month of the year, heat should not
be added to a stream in excess of the amount that will
raise the temperature of the water more than 5 F
(based on the minimum expected flow for that month).
In lakes and reservoirs, the temperature of the epi-
limnion should not be raised more than 3 F by the ad-
dition of heat of artificial origin.
(3) The normal daily and seasonal temperature
fluctuations that existed before the addition of heat due
to other than natural causes should be maintained.
(4) The recommended maximum temperatures that
are not to be exceeded for various species of cold water
fish are given in table III-l.
NOTE.—For streams, total added heat (in BTU's)
might be specified as an allowable increase in tempera-
ture of the minimum daily flow expected for the month
or period in question. This would allow addition of a
constant amount of heat throughout the period. Ap-
proached in this way for all periods of the year, sea-
sonal variation would be maintained. For lakes the
situation is more complex and cannot be specified in
simple terms.
TABLE III-l
[Provisional maximum temperatures recommended as compati-
ble with the well-being of various species of fish and
their associated biota]
93 F: Growth of catfish, gar, white or yellow bass,
spotted bass, buffalo, carpsucker, threadfin shad,
and gizzard shad.
90 F: Growth of largemouth bass, drum, bluegill, and
crappie.
84 F: Growth of pike, perch, walleye, smallmouth bass,
and sauger.
80 F: Spawning and egg development of catfish,
buffalo, threadfin shad, and gizzard shad.
75 F: Spawning and egg development of largemouth
bass, white, yellow, and spotted bass.
68 F: Growth or migration routes of salmonids and for
egg development of perch and smallmouth bass.
55 F: Spawning and egg development of salmon and
trout (other than lake trout).
48 F: Spawning and egg development of lake trout,
walleye, northern pike, sauger, and Atlantic
salmon.
Note.—Recommended temperatures for other species, not
listed above, may be established if and when necessary in-
formation becomes available.
Dissolved oxygen
Oxygen requirements of aquatic life have been
extensively studied. Excellent survey papers are
presented by Doudoroff (1957), Doudoroff and
Shumway (1967), Doudoroff and Warren
(1962), Ellis (1937), and Fry (1960). Much of
the work on temperature requirements also con-
siders oxygen and those bibliographies are equally
valuable.
Most of the research concerning oxygen require-
ments for freshwater organisms deals with fish, but
since fish depend upon other aquatic species for
food and would not remain in an area with an in-
adequate food supply, it seems reasonable to as-
sume that a requirement for fish would serve also
for the rest of the community. The fish themselves
can be grouped into three categories according to
their temperature and oxygen requirements:
(1) the cold-water fish (e.g., salmon and trout),
(2) the warm-water game and pan fish (e.g., bass
and sunfish), and (3) the warm-water "coarse"
fish (e.g., carp and buffalo). The cold-water fish
seem to require higher oxygen concentrations than
the warm-water varieties. The reason is not known,
but it may be related to the fact that, for half
saturation, trout hemoglobin requires an oxygen
partial pressure three or four times that required
by carp hemoglobin under similar circumstances.
Warm-water game and pan fish seem to require a
higher concentration than the "coarse" fish, prob-
ably because the former are more active and
predatory.
Relatively little of the research on the oxygen
requirements of fish in any of these three categories
is applicable to the problem of establishing oxygen
criteria because the endpoints have usually been
too crude. It is useless in the present context to
know how long an animal can resist death by as-
phyxiation at low dissolved oxygen concentrations;
we must know instead the oxygen concentration
that will permit an aquatic population to thrive. We
need data on the oxygen requirements for egg de-
velopment, for newly hatched larvae, for normal
growth and activity, and for completing all stages
of the reproductive cycle. It is only recently that
experimental work has been undertaken on the
effects of oxygen concentration on these more
subtle endpoints. As yet, only a few species have
been studied.
One of the first signs that a fish is being affected
by a reduction of dissolved oxygen (DO) concen-
tration is an increase in the rate at which it venti-
lates its gills, a process accomplished in part by an
increase in the frequency of the opercular move-
ments. The half dozen or so species (chiefly
warm-water game and pan fish) that have been
reported so far show a significant increase in fre-
quency as the DO concentration is reduced from
6 to 5 mg/1 (at about 72 F) and a greater increase
43
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from 5 to 4 mg/1. If the opercular rate is taken as
the criterion by which the adequacy of an oxygen
concentration is to be judged, then such evidence
as we have indicates 6 mg/1 as the required dis-
solved oxygen concentration. Several field studies
have shown, however, that good and diversified
fish populations can occur in waters in which the
dissolved oxygen concentration is between 6 and
5 mg/1 in the summer, suggesting that a minimum
of 6 mg/1 is probably more stringent than neces-
sary for warm-water fishes. Because the oxygen
content of a body of water does not remain con-
stant, it follows that if the dissolved oxygen is
never less than 5 mg/1 it must be higher part of
the time. In some cases, good populations of
warm-water fish, including game and pan fishes,
occur in waters in which the dissolved oxygen may
be as low as 4 mg/1 for short periods. Three mg/1
is much too low, however, if normal growth and
activity are to be maintained. It has been reported
that the growth of young fish is slowed markedly if
the oxygen concentration falls to 3 mg/1 for part
of the day, even if it rises as high as 18 mg/1 at
other times. It is for such reasons as this that oxy-
gen criteria cannot be based on averages. Five and
4 mg/1 are close to the borderline of oxygen con-
centrations that are tolerable for extended periods.
For a good population of game and pan fishes,
the concentration should be considerably more
than this.
The requirements of the different stages in the
life cycles of aquatic organisms must be taken into
account. An oxygen concentration that can be
tolerated by an adult animal, with fully developed
respiratory apparatus, less intense metabolic re-
quirements, and the ability to move away from
adverse conditions, could easily be too low for eggs
and larval stages. The eggs are especially vulner-
able to oxygen lack because they have to depend
upon oxygen diffusing into them at a rate sufficient
to maintain the developing embryos. Hatching,
too, is a critical time; recently hatched young need
relatively more oxygen than adults, but until they
become able to swim for themselves (unless they
are in flowing water) they must depend upon the
oxygen supply in the limited zone around them.
These problems are not as great among species
that tend their eggs and young, suspend their eggs
from plants, or have pelagic eggs, as they are for
salmonids. Salmonids bury their eggs in the gravel
of the stream away from the main flow of the water
thereby requiring a relatively high oxygen concen-
tration in the water that does reach them.
Recommendation: In view of the above considerations
and with the proviso that future research may make
revision necessary, the following environmental con-
ditions are considered essential for maintaining na-
tive populations of fish and other aquatic life:
(1) For a diversified warm-water biota, including
game fish, daily DO concentration should be above
5 mg/1, assuming that there are normal seasonal and
daily variations above this concentration. Under ex-
treme conditions, however, and with the same stipula-
tion for seasonal and daily fluctuations, the DO may
range between 5 mg/1 and 4 mg/1 for short periods of
time, provided that the water quality is favorable in
all other respects. In stratified eutrophic and dystrophic
lakes, the DO requirements may not apply to the
hypolimnion. In shallow unstratified lakes, they should
apply to the entire circulating water mass.
These requirements should apply to all waters ex-
cept administratively established mixing zones. In lakes,
such mixing zones must be restricted so as to limit the
effect on the biota. In streams, there must be no blocks
to migration and there must be adequate and safe
passageways for migrating forms. These zones of pas-
sage must be extensive enough so that the majority of
plankton and other drifting organisms are protected
(see section on zones of passage).
(2) For the cold water biota, it is desirable that DO
concentrations be at or near saturation. This is espe-
cially important in spawning areas where DO levels
must not be below 7 mg/1 at any time. For good growth
and the general well-being of trout, salmon, and other
species of the biota, DO concentrations should not be
below 6 mg/1. Under extreme conditions they may
range between 6 and 5 mg/1 for short periods provided
that the water quality is favorable and normal daily
and seasonal fluctuations occur. In large streams that
have some stratification or that serve principally as mi-
gratory routes, DO levels may be as low as 5 mg/1 for
periods up to 6 hours, but should never be below 4
mg/1 at any time or place.
(3) DO levels in the hypolimnion of oligotrophic
small inland lakes and in large lakes should not be
lowered below 6 mg/1 at any time due to the addition
of oxygen-demanding wastes or other materials.
Carbon dioxide
An excess of "free" carbon dioxide (as distin-
guished from that present as carbonate and bicar-
bonate) may have adverse effects on aquatic ani-
mals. These effects range from avoidance reactions
and changes in respiratory movements at low con-
centrations, through interference with gas ex-
change at higher concentrations, to narcosis and
death if the concentration is increased further. The
respiratory effects seem the most likely to be of
concern in the present connection.
Since the carbon dioxide resulting from meta-
bolic processes leaves the organisms by diffusion,
an increase in external CO, concentration will
make it more difficult for it to diffuse out of the
organism. Thus, it begins to accumulate internally.
The consequences of this internal accumulation
are best known for fish, but presumably the princi-
ples are the same for other organisms. As the CO2
accumulates, it depresses the blood pH, and this
44
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may have detrimental effects. Probably more im-
portant, however, is the fact that the greater the
blood CO2 concentration, the less readily will the
animal's hemoglobin combine with dissolved oxy-
gen. Thus the presence of much CO, raises the
minimum oxygen concentration which is tolerable.
Since the combination of oxygen with hemoglobin
is inversely related to temperature, it is obvious
that CO2, temperature, and oxygen are closely
related. Insufficient data are available at present
to permit us to state the greatest amount of dis-
solved carbon dioxide that all types of aquatic
organisms can tolerate and how these tolerable
concentrations vary with temperature and dis-
solved oxygen. Studies of the effect of CCX on
the oxygen requirements of several species of fish
indicate that CCX concentrations of the order of
25 mg/1 should not be detrimental, provided tne
oxygen concentration ana temperature are within
the recommended limits.
Recommendation: According to our rather meagre
knowledge of the subject, it is recommended that the
free CO2 concentration should not exceed 25 mg/1
Oi!
Oil slicks are barely visible at a concentration of
about 25 gal/sq mi (Amer. Petroleum Inst. 1949).
At 50 gal/sq mi, an oil film is 3.0x10"° inches
thick and is visible as a silvery sheen on the sur-
face. Sources of oil pollution are bilge and ballast
waters from ships, oil refinery wastes, industrial
plant wastes such as oil, grease, and fats from the
lubrication of machinery, reduction works, plants
manufacturing hydrogenated glycerides, free fatty
acids, and glycerine, rolling mills, county drains,
storm-water overflows, gasoline filling stations, and
bulk stations.
Wiebe (1935) showed that direct contact by fish
(bass and bream) with crude oil resulted in death
caused by a film over the gill-filaments. He also
demonstrated that crude oil contains a water-solu-
ble fraction that is very toxic to fish. Galtsoff, et al.
(1935) showed that crude oil contains substances
soluble in sea water that produce an anaesthetic
effect on the ciliated epithelium of the gills of
oysters. Free oil and emulsions may act on the
epithelial surfaces of fish gills and interfere with
respiration. They may coat and destroy algae and
other plankton, thereby removing a source of fish
food, and when ingested by fish they may taint
their flesh.
Setteable oily substances may coat the bottom,
destroy benthic organisms, and interfere with
spawning areas. Oil may be absorbed quickly by
suspended matter, such as clay, and then due to
wind action or strong currents may be transported
over wide areas and deposited on the bottom far
from the source. Even when deposited on the bot-
tom, oil continuously yields water-soluble sub-
stances that are toxic to aquatic life.
Films of oil on the surface may interfere with
reaeration and photosynthesis and prevent the
respiration of aquatic insects such as water boat-
men, backswimmers, the larvae and adults of
many species of aquatic beetles, and some species
of aquatic Diptera ("flies). These insects surface
and carry oxygen bubbles beneath the surface by
means of special setae which can be adversely af-
fected by oil. Berry (1951) reported that oil films
on the lower Detroit River are a constant threat to
waterfowl. Oil is detrimental to waterfowl by de-
stroying the natura! buoyancy and insulation o£
their feathers.
A number of observations maae by various
authors in this country and abroad record the con-
centrations of oil in fresh water which are dele-
terious to different species. For instance, penetra-
tion of motor oil into a fresh water reservoir
used for holding crayfish in Germany caused the
death of about^20,000 animals (Seydell, 1913).
It was established experimentally that crayfish
weighing from 35 to 38 g die in concentrations of
5 to 50 mg/i within 18 to 60 hours. Tests with two
species of fresh water fish, ruff ^small European
perch), and whitefish (fam. Coregonidae) showed
that concentrations of 4 to 16 mg/1 are lethal to
these species in 18 to 60 hours
The toxicity of crude oil from various oil fields
in Russia varies depending on its chemical com-
position. The oil used by Veselov (1948) in the
studies of the pollution of Belaya River (a tribu-
tary in the Kama in European Russia) belongs to a
group of methano-aromatic oils with a high con-
tent of asphalt, tar compounds, and sulfur. It
contains little paraffin and considerable amounts
of benzene-ligroin. Small crucian carp (Carassius
carassius) 7-9 cm long were used as the bioassay
test animal. This is considered to be a hardy fish
that easily withstands adverse conditions. The
water soluble fraction of oil was extracted by
shaking 15 ml of oil in 1 liter of water for 15
minutes. The oil film was removed by filtration.
Dissolved oxygen was controlled. A total of 154
tests were performed using 242 fishes. The average
survival time was 17 days at the concentration of
0.4 ml/1 of oil but only 3 days at the concentration
of 4 ml/1. Further increase in concentration had no
appreciable effect on fish mortality.
Seydell (1913) stated that the toxicity of Rus-
sian oil is due to naphthenic acids, small quantities
of phenol, and volatile acids (Veselov, 1948).
45
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Cairns (1957) reports the following 96-hour TLm
values of naphthenic acid for bluegill sunfish
(Lepomis macrochirus)—5.6 mg/1; pulmonate
snail (Physa heterostropha)—6.1 to 7.5 mg/1 (in
soft water), and diatom (species not identified) —
41.8 to 43.4 mg/1 in soft water and 28.2 to 79.8
mg/1 in hard water. Naphthenic acid (cyclohexane
carboxylic acid) is extracted from petroleum and
is used in the manufacture of insecticides, paper,
and rubber.
Chipman and Galtsoff (1949) report that crude
oil in concentrations as low as 0.3 mg/1 is ex-
tremely toxic to fresh water fish. Dorris, Gould,
and Jenkins (1960) made an intensive study of the
toxicity of oil refinery effluents to fathead minnows
in Oklahoma. By standard bioassay procedures,
they found that mortality varied between 3.1 per-
cent to 21.5 percent after 48 hours of exposure to
untreated effluents. They concluded that toxicity
rather than oxygen demand is the most important
effect of oil refinery effluents on receiving streams.
Pickering and Henderson (1966b) reported the
results of acute toxicity studies of several impor-
tant petrochemicals to fathead minnows, bluegills,
goldfish, and guppies in both soft water and hard
water. Standard bioassay methods were used. Be-
cause several of the compounds tested have low
solubility in water, stock solutions were prepared
by blending the calculated concentrations into 500
ml of water before addition to the test container.
Where necessary, pure oxygen was supplied by
bubbling at a slow rate. The petrochemicals tested
were benzene, chlorobenzene, 0-chlorophenol, 3-
chloropropene, 0-cresol, cyclohexane, ethyl ben-
zene, isoprene, methyl methacrylate, phenol, 0-
phthalic anhydride, styrene, toluene, vinyl acetate,
and xylene. These petrochemicals are similar in
their toxicities to fish, with 96-hour TLm values
ranging from 12 to 368 mg/1. Except for isoprene
and methyl methacrylate, which are less toxic,
values for all four species of fish for the other
petrochemicals ranged from 12 to 97 mg/1, a rela-
tively small variation. In general, 0-chlorophenol
and 0-cresol are the most toxic and methyl meth-
acrylate and isoprene are the least toxic.
Recommendation: In view of available data, it is con-
cluded that to provide suitable conditions for aquatic
life, oil and petrochemicals should not be added in
such quantities to the receiving waters that they will:
(1) produce a visible color film on the surface, (2)
impart an oily odor to water or an oily taste to fish
and edible invertebrates, (3) coat the banks and bot-
tom of the water course or taint any of the associated
biota, or (4) become effective toxicants according to
the criteria recommended in the "Toxicity" section.
Turbidity
Turbidity is caused by the presence of suspended
matter such as clay, silt, finely divided organic
matter, bacteria, plankton, and other microscopic
oragnisms. Turbidity is an expression of the optical
property of a sample of water which causes light to
be scattered and absorbed rather than transmitted
in straight lines through the sample. Excessive
turbidity reduces light penetration into the water
and, therefore, reduces photosynthesis by phyto-
plankton organisms, attached algae, and sub-
mersed vegetation.
The Jackson candle turbidimeter (Standard
Methods for the Examination of Water and Waste-
water, 12th edition. 1965) is the standard instru-
ment for making measurements of turbidity. Field
determinations, however, are made with direct-
reading colorimeters calibrated for this test and the
results are expressed as Jackson turbidity units
(JTU).
Silt and sediment are particularly damaging to
gravel and rubble-type bottoms. The sediment fills
the interstices between gravel and stones, thereby
eliminating the spawning grounds of fish and the
habitat of many aquatic insects and other inverte-
brate animals such as mollusks, crayfish, fresh
water shrimp, etc. Tarzwell (1957) observed that
bottom organisms from a silted area averaged only
36 organisms/sq ft compared to 249/sq ft in a
non-silted area. Smith (1940) reported that silting
reduced the bottom fauna of the Rogue River by
25 to 50 percent. Observations in Oregon by Wag-
ner (1959) and Ziebell (1960) showed an 85-
percent decline in productivity of aquatic insect
populations below a gravel dragline operation.
Turbidities in the affected area were increased
from zero to 91 mg/1 and suspended solids from
2 mg/1 upstream to 103 mg/1 downstream.
Buck (1956) investigated several farm ponds,
hatchery ponds, and reservoirs over a 2-year
period. He observed that the maximum production
of 161.5 Ib/acre occurred in farm ponds where
the average turbidity was less than 25 JTU. Be-
tween 25 and 100 JTU, fish yield dropped 41.7
percent to 94 Ib/acre, and in muddy ponds, where
turbidity exceeded 100 JTU, the yield was only
29.3 Ib/acre or 18.2 percent of clear ponds.
Herbert and Merkens (1961), using a mixture
of kaolin and diatomaceous earth, demonstrated
that long-term exposure of rainbow trout to 100—
200 mg/1 could be harmful. At 270 and 810 mg/1,
a high percentage of the fish died. Wallen (1951)
studied the effects of montmorillonite clay on 16
species of warm-water fish. Results are shown in
table III-2. It is shown that fish can tolerate high
46
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turbidities for short periods, a fortunate adaptation
for river species. Fish productivity is ultimately
dependent upon plant life and a good bottom
fauna. There can be little of either above 200 JTU
if that turbidity is maintained continuously. The
Aquatic Life Advisory Committee of the Ohio
River Valley Water Sanitation Commission
(ORSANCO) Second Progress Report (1956)
points out that fish withstand turbidities of 5,000
mg/1 or more with no direct harmful results, but
the productivity of the bottom areas is very low
and the fish populations are small.
TABLE 111-2. Average Turbidities Found To Be
Fatal to Fish
Species
Length of
exposure (days)
Turbidity
(mg/l)
Large mouth bass 7.6 101,000
Pumpkin seed sunfish 13 69,000
Channel catfish 9.3 85,000
Black bullhead 17 222,000
Golden shiner 7.1 166,000
Ellis (1937) summarized the results of 2,344
light penetration determinations made at 585 sta-
tions on streams throughout the United States. The
determinations were made of the millionth inten-
sity depth (m.i.d.), which is the depth in milli-
meters of water of the given turbidity required to
screen out 99.9999 percent of the light entering at
the surface. A photoelectric apparatus described
by Ellis (1934b) was used and determinations
were made after filtering the water through bolting
silk.
The turbidity of rivers varies widely in different
parts of the country. Ellis (1937) defined clear
streams as those with a m.i.d. of 5.00 to infinity;
cloudy streams, 4.90-1.00 meters; turbid, 0.99-
0.50; very turbid, 0.49-0.30; muddy, 0.29-0.15;
very muddy, 0.14-0.00 meters.
In Mississippi River side channels and flowing
stream tributaries with good fish fauna, 4 percent
were clear, 11 percent cloudy, 3 percent were very
muddy. In these waters, with medium, poor, or no
fish fauna 1 percent were clear, 18 percent cloudy,
11 percent turbid, 14 percent very turbid, 38 per-
cent muddy, and 18 percent very muddy.
Based on 6,000 light penetration determinations
on inland streams, he concluded that, for good pro-
duction of fish and aquatic life, the silt load of
these streams should be reduced so that the mil-
lionth intensity depth would be greater than 5
meters.
Good farming practices can do a great deal to
prevent silt from reaching streams and lakes. Road
building and housing development projects, placer
mining, strip rrtining, coal and gravel washing, and
unprotected road cuts are important sources of
turbidity that can be reduced with planning, good
housekeeping, and regulation.
Natural turbidities within watersheds should be
determined. For example, in some Western States
many streams have a turbidity below 25 JTU for
most of the year. In those states, the water pollu-
tion control agency might specify that no wastes
should be discharged which would raise the tur-
bidity of the receiving water above 25 JTU.
From the above discussion it can be seen that
natural turbidity varies greatly in different parts of
the country.
Recommendation: Turbidity in the receiving water
due to a discharge should not exceed 50 JTU in warm-
water streams or 10 JTU in cold-water streams.
There should be no discharge to warm-water lakes
which will cause turbidities exceeding 25 Jackson Units.
The turbidity of cold-water or oligotrophic lakes should
not exceed 10 units.
Settleable solids
Settleable solids include both inorganic and or-
ganic materials. The inorganic components include
sand, silt, and clay originating from such sources
as erosion, placer mining, mine tailing wastes, strip
mining, gravel washing, dusts from coal washeries,
loose soils from freshly plowed farm lands, high-
way, and building projects. The organic fraction
includes such settleable materials as greases, oils,
tars, animal and vegetable fats, paper mill fibers,
synthetic plastic fibers, sawdust, hair, greases from
tanneries, and various settleable materials from city
sewers. These solids may settle out rapidly and
bottom deposits are often a mixture of both inor-
ganic and organic solids. They may adversely af-
fect fisheries by covering the bottom of the stream
or lake with a blanket of material that destroys the
bottom fauna or the spawning grounds of fish.
Deposits containing organic materials may deplete
bottom oxygen supplies and produce hydrogen
sulfide, carbon dioxide, methane, or other noxious
gases.
Some settleable solids may cause damage by
mechanical action.
Water Quality Criteria for European Freshwater
Fish (European Inland Fisheries Advisory Com-
mission, 1964) discusses chemically inert solids
in waters that are otherwise satisfactory for the
maintenance of freshwater fisheries. It is indicated
that good or moderate fisheries can be maintained
in waters that normally contain 25 to 80 mg/1 sus-
pended solids, but that the yield of fish might be
47
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lower than in waters containing 25 mg/1 or less.
Waters normally containing 80 to 400 mg/1 sus-
pended solids are unlikely to support good fresh-
water fisheries.
Recommendation: Since it is known that even minor
deposits of settleable materials inhibit the growth of
normal stream or lake flora and fauna, it is recom-
mended that no settleable materials be added to these
waters in quantities that adversely affect the natural
biota.
Color
The color of water is attributed to substances
in solution after the suspensoids have been re-
moved. It may be of organic or mineral origin.
Organic sources are humic materials, peat, plank-
ton, rooted and floating aquatic plants, tannins,
etc. Inorganic sources are metallic substances such
as iron and manganese compounds and chemicals,
dyes, etc. Many industries discharge materials that
contribute to the color of water. Among them are
pulp and paper mills, textile mills, refineries,
manufacturers of chemicals and dyes, explosives,
naiiworks. tanneries, etc.
Standard Methods for the Examination of Water
and Wastewater, 12th edition (1965), describes
the standard platinum-cobalt method of determin-
ing color after centrifugation. The unit of color
considered as standard is the color produced by
one mg/1 of platinum in water. Results are ex-
pressed as units of color. Color in excess of 50
units may limit photosynthesis and have a dele-
terious effect upon aquatic life, particularly phyto-
plankton, and the benthos.
Water absorbs light differentially. A layer of
distilled water 1 meter in thickness absorbs 53 per-
cent of the solar radiation. It absorbs 30 percent of
the red-orange band (6,500 angstrom units) but
less than 5 percent of the blue (4,500 angstrom
units). These are the portions of the spectrum that
are absorbed and utilized to the greatest extent by
chlorophyll. The band at 7,500 angstrom units is
over 90 percent absorbed.
Natural waters absorb far more light. The light
intensity at which the amount of oxygen produced
photosynthetically is balanced by the amount of
oxygen used for respiration in some submerged
vascular plants is 5% of full sunlight on clear
summer days. It is estimated that 25 to 50 percent
of full sunlight is necessary for many green aquatic
plants to reach maximum photosynthesis. The
ORSANCO committee observed that the 25-per-
cent level of solar radiation is not reached in many
of the larger streams and they considered it desira-
ble to restrict the addition of any substances that
reduce light penetration and hence limit the pri-
mary productivity of aquatic vegetation.
Recommendation: For effective photosynthetic pro-
duction of oxygen, it has been found that at least
10 percent of incident light is required. Therefore,
10 percent of the incident light should reach the bottom
of any desired photosynthetic zone in which adequate
dissolved oxygen levels are to be maintained.
Floating materials
Floating materials include sawdust, peelings
and other cannery wastes, hair and fatty materials
from tanneries, wood fibers, containers, scums, oil,
garbage, floating materials from untreated munic-
ipal and industrial wastes, tars and greases, and
precipitated chemicals.
Wastes from paper mills, vinegar plants, cane
mills, and other industries may contribute nutrients
or produce conditions in streams that foster the
growth of Sphaerotilus (Chlamydobacteriales) or
similar iron or sulfur bacteria. These floating
growths not only clog fishermen's nets, but also
smother out the spawning grounds and habitat of
all forms of aquatic life.
Recommendation: All such floating and settleable sub-
stances should be excluded from streams and lakes.
Tainting substances
Among the materials that are responsible for
objectionable tastes in fish are hydrocarbons,
phenolic compounds, sodium pentachlorophenate
(used for slime control in cooling towers), coal
tar wastes, gas wastes, sewage containing phenols,
coal-coking wastes, outboard motor exhaust
wastes, and petroleum refinery wastes. Kraft paper
mill wastes, sulfides, mercaptans, turpentine,
wastes from synthetic rubber and explosives fac-
tories, algae, resins and resin acids also contribute
to objectional tastes in fish. Twenty gallons per
acre of kerosene or diesel fuel will produce an off-
flavor in bass and bluegills which persists for 4 to
6 weeks. The Aquatic Life Advisory Committee
of ORSANCO in its Third Progress Report
(1960), lists the concentrations (table III-3) of
phenolic substances that cause taste and odor.
Albersmeyer and Erichsen (1959) found that car-
bolated oil and light oil, both dephenolated, im-
part a taste to fish flesh more pronounced than
that caused by naphthalene and methyl naphtha-
lene. They concluded that the hydrocarbons are
more responsible for tastes in fish flesh than the
phenolic compounds. Boetius (1954) found that
chlorophenol could produce unpleasant flavor in
fish at a concentration of only 0.0001 mg/1.
48
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TABLE 111-3. Concentration of Phenolic Com-
pounds That Cause Tainting of Fish Flesh
After Bandt (1955) page 77 (except for phenol).
Compound or
waste
Concentration
affecting taste
and odor (mg/l)
Fish tested
Pure compounds:
Phenol 15 to 25 Trout, carp, tench,
chub, eel, min-
now, perch, blue-
gill, pike, gold-
fish.
Cresols 10 Tench, carp, eel,
trout, minnow.
Xylenols 1 to 5 Roach, perch, carp.
Pyrocatechol 2 to 5 Perch, carp, roach.
Pyrogallol 20 to 30 Roach, carp.
P-Qumone 0.5 Carp, tench, roach.
Pyridme 5 Roach, carp.
Naphthalene 1 Roach.
Alpha Naphthol__0.5 Roach, carp.
Quinolme 0.5 to 1.0 do.
Chlorophenpl ___0.1
Mixed phenolic wastes:
Coal-coking
wastes 0.02 to 0.1 Freshwater fish.
Coal-tar wastes__0.1 do.
Phenols in
polluted river_.0.02 to 0.15___ Minnows.
Sewage contain-
ing phenols __0.1 Freshwater fish.
A preliminary laboratory study (English, Mc-
Dermott, and Henderson, 1963) shows that out-
board motor exhaust damages the quality of water
in several ways, the most noticeable of which is
causing unpleasant taste and odor in the water and
off-flavoring of fish flesh. A later field study, Eng-
lish et al. (1963a, b) and Surber et al. (1965)
determined the threshold level of tainting of fish in
pond and lake waters to be about 2.6 gal/acre-foot
of fuel, accumulating over a 2-month period. The
gasoline used was regular grade and the lubricating
oil (1/2 pint/gal) was a popular brand of packaged
outboard motor oil.
Recommendation: Materials that impart odor or taste
to fish flesh or other freshwater edible products such as
crayfish, clams, prawns, etc., should not be allowed to
enter receiving waters at levels that produce tainting.
Where it seems probable that a discharge may result in
tainting of edible aquatic products, bioassays and taste
panels are suggested for determining whether tainting
is likely.
Radioactive materials in fresh
and marine waters
Ionizing radiation, when absorbed in living
tissue in quantities substantially above that of nat-
ural background, is recognized as injurious. It is
necessary, therefore, to prevent excessive levels of
radiation from reaching any organism we wish to
preserve, be it human, fish, or invertebrate. Beyond
the obvious fact that they emit ionizing radia-
tion, radioactive wastes are similar in many re-
spects to other chemical wastes. Man's senses can-
not detect radiation unless it is present in massive
amounts. Radiation can be detected, however, by
means of electronic instruments and quantities
present at very low levels in the environment can
be measured with remarkable accuracy. Because
of the potential danger, the disposal of radioactive
materials has been well planned and controlled.
Injuries and loss of life from disposal of radioactive
materials or from accidents involving these mate-
rials have been minimal. Four factors have con-
tributed to this safety record: (1) scientists and
legislators were aware of the dangers associated
with the release of radioactive materials into the
environment prior to the need for disposal; (2) re-
search has progressed to protect man against ra-
diation effects and levels of radiation that could be
released; (3) as knowledge of nuclear energy in-
creased, standards were developed for handling,
shipping, and disposing of radioactive substances;
and (4) an extensive monitoring program was in-
augurated and has been functioning for years.
Upon introduction into an aquatic environment,
radioactive wastes can: (1) remain in solution
or in suspension, (2) precipitate and settle to
the bottom, or (3) be taken up by plants and ani-
mals. Immediately upon introduction of radioac-
tive materials into the water, certain factors inter-
act to dilute and disperse these materials, while
simultaneously other factors tend to concentrate
the radioactivity. Among those factors that dilute
and disperse radioactivity are currents, turbulent
diffusion, isotopic dilution, and biological trans-
port. Radioactivity is concentrated biologically by
uptake directly from the water and passage
through food webs, chemically and physically by
adsorption, ion exchange, coprecipitation, floccula-
tion, and sedimentation.
Radioactive wastes in the aquatic environment
may be cycled through water, sediment, and the
biota. Each radionuclide tends to take a charac-
teristic route and has its own rate of movement
from component to component prior to coming to
rest in a temporary reservoir, one of the three
components of the ecosystem. Isotopes can move
from the water to the sediments or to the biota. In
effect, the sediments and biota compete for the
isotopes in the water. Even though in some in-
stances sediments are initially successful in remov-
ing large quantities of radionuclides from the
water, and thus preventing their immediate uptake
by the biota, this sediment-associated radioactivity
49
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may later affect many benthic species by exposing
them to radiation. Also, any radioactivity leached
from the sediments back to the water again be-
comes available for uptake by the biota. Even be-
fore the radioactivity is leached from the sediment,
it may become available to the biota due to a
variation in the strength of the bonds between the
different radionuclides and the sediment particles.
Loosely bound radionuclides can be "stripped"
from particles of sediment and utilized by bottom-
feeding organisms.
Plants and animals, to be of any significance in
the cycling of radionuclides in the aquatic environ-
ment, must accumulate the radionuclide, retain it,
be eaten by another organism, and be digestible.
However, even if an organism accumulates and
retains a radionuclide and is not eaten before it
dies, the radionuclide will enter the "biological
cycle" through organisms that decompose the dead
organic material into its elemental components.
Plants and animals that become radioactive in this
biological cycle can pose a health hazard when
eaten by man.
Aquatic life may receive radiation from radio-
nuclides present in the water and substrate and
also from radionuclides that may accumulate
within their tissues. Humans can acquire radionu-
clides via many pathways, but among the most
important are drinking water or edible fish and
shellfish that have concentrated nuclides from the
water. In order to prevent unacceptable doses of
radiation from reaching humans, fish, and other
important organisms, the concentrations of radio-
nuclides in water, both fresh and marine, must be
restricted.
The effects of radiation on organisms have been
the subject of intense investigation for many years.
Careful consideration of pertinent portions of the
vast amount of available information by such or-
ganizations as the International Commission on
Radiological Protection (ICRP), the National
Committee on Radiation Protection and Measure-
ments (NCRP), and the Federal Radiation Coun-
cil (FRC) has resulted in recommendations on the
maximum doses of radiation that people may be
allowed to receive under various circumstances
(U.S. Department of Commerce, 1963). The rec-
ommended levels for the general public are sub-
stantially more conservative than those for persons
who work with radiation sources or radionuclides,
but in both cases the recommended levels assume
that the exposure will be sustained essentially
throughout the life or period of employment of the
person.
The ICRP and NCRP have calculated the quan-
tities of individual radionuclides that a person can
ingest each day without accumulating levels in
various body organs that deliver radiation doses
in excess of the recommended limits. These quanti-
ties contained in the volume of water ingested
daily (2.2 liters) are referred to as "maximum per-
missible concentrations (MPC) in water." The
FRC, recognizing that people may jngest radio-
nuclides from foods and other sources as well as
from drinking water, has provided guidance on
the basis of transient rates of intake from all
sources, but only for a few nuclides (radium-226,
iodine-131, strontium-90, and strontium-89).
The PHS Drinking Water Standards (US-
DHEW, 1962) are responsive to the recom-
mendations of the FRC, ICRP, and NCRP, and
provide appropriate protection against unaccept-
able radiation dose levels to people where drinking
water is the only significant source of exposure
above natural background. Where fish or other
fresh or marine products that have accumulated
radioactive materials are used as food by humans,
the concentrations of the nuclides in the water
must be further restricted to provide assurance
that the total intake of radionuclides from all
sources will not exceed the recommended levels.
The radiation dose received by fish and other
aquatic forms will be greater than that received by
people who drink the water or eat the fish. Even
so, this does not place the fish in risk of suffering
radiation damage. The radiation protection guides
for people have been established with prudence,
for continued exposure over a normal life span,
and with appropriate risk (safety) factors. Virtu-
ally all of the available evidence shows that the
concentrations of radionuclides in fish and shell-
fish that would limit their use as food are substan-
tially below the concentrations that would injure
the organisms from radiation. Therefore, at this
time there appears to be no need for establishing
separate criteria for radioactive materials in water
beyond those needed to limit the intake to humans.
Recommendation: (1) No radioactive materials
should be present in receiving waters as a consequence
of the failure of an installation to exercise practical and
economical controls to minimize releases. This recom-
mendation is responsive to the recommendations of the
FRC that: "There can be no single permissible or ac-
ceptable level of exposure without regard to the reason
for permitting the exposure. It should be general prac-
tice to reduce exposure to radiation, and positive effort
should be carried out to fulfill the sense of these recom-
mendations. It is basic that exposure to radiation should
result from a real determination of its necessity."
(2) No radionuclide or mixture of radionuclides
should be present at concentrations greater than those
specified in the PHS Drinking Water standards
(USDHEW, 1962). This recommendation assures that
people will receive no more than acceptable amounts
50
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of radioactive materials from aquatic sources and that
fish living in the water will not receive an injurious
dose of radiation.
(3) The concentrations of radioactive materials
present in fresh, estuarine, and marine waters should be
less than those that would require restrictions on the
use of organisms harvested from the area in order to
meet the Radiation Protection Guides recommended
by the Federal Radiation Council.
This recommendation assures that fish and other
fresh water and marine organisms will not accu-
mulate radionuclides to levels that would make
them unacceptable for human food. It also limits
the radiation dose that the organisms would receive
from internally deposited nuclides to levels below
those that may be injurious. Some workers (Car-
ritt, 1959; Isaacs, 1962; Pritchard, 1959) have
recommended "maximum permissible levels for
sea water" based on various assumptions of dis-
persion, uptake by marine organisms, and the use
of the organisms as food by people. While these
recommendations are most useful as a first ap-
proximation in predicting safe rates of discharge
of radioactive wastes, their applicability as water
quality criteria is limited and they are not intended
for use in fresh or estuarine waters where the con-
centrations of a great variety of chemical elements
vary widely. Because it is not practical to general-
ize on the extent to which many of the important
radionuclides will be concentrated by fresh water
and marine forms, nor on the extent to which these
organisms will be used for food by people, no at-
tempt is made here to specify MFC for either sea
water or fresh water in reference to uptake by the
organisms. Rather, each case requires a separate
evaluation that takes into account the peculiar fea-
tures of the region. Such an evaluation should be
approved by an agency of the State or Federal
Government in each instance of radioactive con-
tamination in the environment. In each particular
instance of contamination, the organisms present,
the extent to which these organisms concentrate
the radionuclides, and the extent to which man
uses the organisms as food must be determined, as
well as the rates of release of radionuclides must be
based on this information.
Plant nutrients and nuisance
organisms
All terrestrial biological processes plus the ma-
jority of man's activities ultimately result in waste
products in various stages of decomposition. A
portion of these sooner or later enter surface fresh-
waters. These waste products include a rather
abundant amount of plant nutrients such as nitro-
gen, phosphorus, carbon, and other elements.
Subsequently, these plant nutrients are incorpo-
rated into organic matter by aquatic plants.
Surface water areas are like land areas in that
some type of vegetation will occupy any suitable
habitat. Thus, the more abundant the nutrient sup-
ply, the more dense the vegetation, provided other
environmental factors are favorable. In the aquatic
habitat, these growths may be bacteria, aquatic
fungi, phytoplankton, filamentous algae, sub-
mersed, emersed, floating, and marginal water
plants. Practically all aquatic plants may be de-
sirable at one time or another and in one habitat
or another. However, when they become too dense
or interfere with other uses of the water or of the
aquatic habitat, they become nuisance growths.
Some sheath-forming bacteria are the primary
nuisance-type growths in rivers, lakes, and ponds.
A notable problem associated with this group oc-
curs in areas subjected to organic enrichment. The
most common offenders belong to the genus Sphae-
rotilus. These bacteria are prevalent in areas re-
ceiving raw domestic sewage, improperly stabilized
paper pulp effluents or effluents containing simple
sugars. The growths they produce interfere with
fishing by fouling lines, clogging nets, and gener-
ally creating unsightly conditions in the infested
area. Their metabolic demands while they are liv-
ing and their decomposition after death impose a
high BOD load on the stream and can severely
deplete the dissolved oxygen. It has been suggested
that large populations of Sphaerotilus render
the habitat noxious to animals and hence its
presence may actively exclude desirable fish and
invertebrates.
The freshwater algae are diverse in shape,
color, size, and habitat. A description of all spe-
cies of algae would be as comprehensive as writing
about all land plants, mosses, ferns, fungi, and
seed plants.
They may be free floating (planktonic) or they
may grow attached to the substrate (benthic or
epiphytic types). They may be macroscopic or
microscopic and are single-celled, colonial, or fila-
mentous. They are the basic link in the conversion
of inorganic constituents in water into organic
matter. When present in sufficient numbers, these
plants impart a green, yellow, red, or black color
to the water. They may also congregate at or
near the water surface and form so-called "water-
bloom" or "scum."
A major beneficial role of algae is the removal
of carbon dioxide from the water by photosyn-
thesis during daylight and the production of oxy-
gen. Algae, like other organisms, continually
51
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respire and produce carbon dioxide. The amount
of oxygen produced during active photosynthesis
is many times the amount of carbon dioxide re-
leased during the night or on cloudy days when
photosynthesis is inhibited or stopped.
Limited concentrations of algae are not trouble-
some in surface waters; however, overproduction
of various species is considered undesirable for
many water uses. A relatively abundant growth of
planktonic algae in waters 3 feet or deeper will
shade the bottom muds sufficiently to prevent
germination of seeds and halt the growth of prac-
tically all rooted submersed and emersed aquatics,
thus removing an important source of food for
ducks and other water fowl.
Some blue-green algae, many green algae, and
some diatoms produce odors and scums that make
waters less desirable for swimming. Dense growths
of such planktonic algae may limit photosynthetic
activity to a layer only a few inches beneath the
surface of the water. Under certain conditions, the
populations of algae may die and their decomposi-
tion will deplete dissolved oxygen in the entire
body of water. Certain sensitive people are allersic
to many species of planktonic algae blooming in
waters used for swimming.
It is claimed that some species of algae cause
gastric disturbances in humans who consume such
infested waters. Several species of blue-green algae
produce, under certain conditions, toxic organic
substances that kill fish, birds, and domestic ani-
mals. Some of the genera that contain species
which may produce toxins are Anabaena, Ana-
cystis, Aphanizomenon, Coleolosphaerium, Gloeo-
trichia, Microcystis, Nodularia, and Nostoc. Some
species of Chlorella, a green alga, also are toxic.
Various species of single, as well as branched
filamentous forms of algae, grow in both cool
and warm weather and when they become over-
abundant are generally considered to be a nui-
sance in whatever body of water they occur. Most
species of these algae are generally distributed over
the United States.
Many forms of plankton and filamentous algae
clog sand filters in water treatment plants, produce
undesirable tastes and odors in drinking water,
and secrete oily substances that interfere with do-
mestic use and manufacturing processes. Some
algae cause water to foam during heating as well
as metal corrosion and the clogging of screens,
filters, and piping. Algae also coat cooling towers
and condensers causing these units to become in-
effective. In Lake Superior, complaints have been
made that diatoms such as Tabellaria, Synedra,
Cymbella, and Fragilaria, and the chrysophyte,
Dinobryon, may be the cause of slimes on fishnets.
Filamentous algae may interfere with the opera-
tion of irrigation systems by clogging ditches,
wires, and screens and thus seriously impede the
flow of water. Filamentous algae in ponds, lakes,
and reservoirs may cause depletion of naturally
occurring and added nutrients that could other-
wise be used to produce unicellular algae that are
more commonly used as food by fish. Dense
growths of filamentous algae may reduce the total
fish production and seriously interfere with har-
vesting the fish either by hook and line fishing,
seining, or draining. Such growths can also cause
overpopulation, resulting in stunting and the pres-
ence of large numbers of small fish. Under cer-
tain conditions, growths of filamentous algae on
pond or lake bottoms become so dense that they
eliminate spawning areas of fish and possibly inter-
fere with the production of invertebrate fish food.
Submersed plants are those which produce all
or most of their vegetative growth beneath the
water surface. In many instances these plants have
an underwater leaf form, a totally different floating
or emersed leaf form, and flowers on an aerial
stalk. Abundant growth of these weeds is depend-
ent upon depth and turbidity of water, and sub-
stratum. For most submersed plants in clear water,
8 to 10 feet is the maximum depth for growth in
clear water as they must receive sufficient light
for photosynthesis when they are seedlings. Most
of these submersed aquatic plants appear capable
of absorbing nutrients as well as herbicides through
either their roots or vegetative parts.
Emersed plants are rooted in bottom muds and
produce a majority of their leaves and flowers at
or above the water surface. Some species have
leaves that are flat and float entirely upon the
water surface. Other species have leaves that are
saucer-shaped or whose margins are irregular or
fluted. The latter types of leaves do not float
entirely upon the water surface.
Marginal plants are probably the most widely
distributed of the rooted aquatic plants. Members
of this group are varied in size, shape, and prefer-
ence of habitat. Many species are adapted for
growth from moist soils into water up to 2 feet
deep or more. Other species are limited to moist
soil or entirely to a watery habitat.
There are some species of floating plants that are
rather limited in their distribution while others
are widespread throughout the world. Plants in
this group have true roots and leaves, but instead
of being anchored in the soil they float about on
the water surface. Buoyancy of the plant is ac-
complished through modification of the leaf (in-
cluding covering of the leaf surface) and leaf
petiole. Most species have well-developed root
52
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systems which collect nutrients from the water.
Species designated as weeds are not necessarily
such in all places and at all times. For example,
many submersed, floating, and emersed plants that
normally interfere with boating, swimming, and
fishing are regarded as desirable growths in water-
fowl refuge areas. Rooted plants with floating
leaves, such as water lillies and watershield, and
those that float upon the surface, such as water
hyacinth, elodea, parrotweed, alligatorweed, and
duckweed, are considered highly objectionable for
many water uses. In clear water areas, however,
where artificial or natural fertilization is moderate,
the removal of these surface-shading plants may
permit sunlight to penetrate to the bottom muds
and submersed plants soon will occupy these
waters. These submersed plants generally are more
objectionable in an area than the original surface-
covering plants.
Most emersed, marginal, and a few submersed
plants and filamentous algae produce growths that
provide a suitable habitat for the development of
anopheline and other pest-type mosquitoes as well
as a hiding place for snakes. They are excellent
habitats for damselflies and some aquatic beetles.
Most rooted and floating aquatic plants can
seriously interfere with navigation of small rec-
reational craft and large commercial boats in in-
fested areas. Such problems are prevalent in
intercoastal waterways and in some streams in
the Gulf States area. Water shortages due to con-
sumption by undesirable aquatic plants or reduc-
tion in carrying capacity of an irrigation or drain-
age canal through excessive vegetation can result
in decreased crop quality, yield, or even crop
failure.
Submersed and emersed weeds consume nutri-
ents, either available or added, that could other-
wise be used to grow desirable planktonic algae
in impounded waters. Thus, the presence of ex-
cessive rooted plants may reduce total fish pro-
duction in the infested body of water. Extensive
growth of weeds provides dense cover that allows
the survival of excessive numbers of fish resulting
in overcrowding and stunting as well as interfer-
ing with harvesting the fish by hook and line or
other methods. There is evidence that rank growths
of submersed, emersed, or floating weeds may de-
plete the dissolved oxygen supply in shallower
water and that fish tend to leave these areas if
there are open-water areas available of better
quality. Although they carry on the process of
photosynthesis, their multicellular structure often
makes them less effective in re-oxygenating the
water.
All the elements essential for plant growth are
yet to be determined. Some of the elements known
to be important are nitrogen, phosphorus, potas-
sium, magnesium, calcium, manganese, iron, sili-
con (for diatoms), sulfur (as sulfates), oxygen,
and carbon. In many habitats, abundance of the
first two elements, N (nitrogen) and P (phos-
phorus), promotes vegetative production if other
conditions for growth are favorable. Most algae
also require some simple organics, such as amino
acids and vitamins, and many trace elements, such
as manganese and copper. Not only are the various
factors important, but their relative abundance and
combined affect can be of even greater importance.
Limited laboratory studies made to date indicate
that different species of algae have somewhat dif-
ferent phosphorus requirements with the range
of available phosphorus usually falling between
0.01 and 0.05 mg/1 as phosphorus. At these levels,
when other conditions are favorable, blooms may
be expected. As has been pointed out by the Sub-
committee on Water Quality Criteria for Public
Water Supply, the total phosphorus is of outstand-
ing importance. While there is no set relationship
between total and available phosphorus (because
the ratio varies with season, temperature, and plant
growth), the total phosphorus is governing as it
is the reservoir that supplies the available phos-
phorus. It is believed that allowable total phos-
phorus depends upon a variety of factors; e.g.,
type of water, character of bottom soil, turbidity,
temperature, and especially desired water use. Al-
lowable amounts of total phosphorus will vary,
but in general it is believed that a desirable guide-
line is 100 /xg/1 for rivers and 50 /xg/1 where
streams enter lakes or reservoirs (recommended
by the Public Water Supply Subcommittee).
The nitrogen-phosphorus ratio is also of impor-
tance. The ratio varies with the water, season, tem-
perature, and geological formation, and may range
from 1 or 2:1 to 100:1. In natural waters, the
ratio is often very near 10:1, and this appears to
be a good guideline for indicating normal condi-
tions.
The major sources of nitrogen entering fresh
waters are atmospheric (approximately 5 Ibs/
acre/year), (Hutchinsen, 1957), domestic sewage
effluents, animal and plant processing wastes, ani-
mal manure, fertilizer and chemical manufacturing
spillage, various types of industrial effluents, and
agricultural runoff.
The major sources of phosphorous entering
fresh waters are domestic sewage effluents (in-
cluding detergents), animal and plant processing
wastes, fertilizer and chemical manufacturing spill-
age, various industrial effluents, and, to a limited
extent, erosion materials in agricultural runoff.
53
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Phosphorous entering an ecosystem may produce
a high oxygen demand. It has been pointed out
that 1 milligram of phosphorous from an organic
source demands about 160 milligrams of oxygen
in a single pass through the phosphorus cycle to
complete oxidation. Thus the oxidation of organic
matter, the growth of which has been induced by
adding phosphorus, may bring about a great reduc-
tion of oxygen in a lake or stream.
Dissolved carbon in the form of simple organic
compounds can be utilized by many kinds of algae.
These types of carbon compounds are also used
directly as a source of food by many animals.
Varying amounts of simple organic compounds
containing carbon are found in sewage and several
types of industrial wastes. Other more complex
forms of organic carbon can be utilized by bac-
teria. The most common nuisance growth that
becomes very abundant in the presence of very
small amounts of carbon is Sphaerotilus. Patrick
(unpublished data) has shown that the addition
of 0.05-0.1 mg/1 of glucose, without changing
other ecological conditions, may produce nuisance
growths.
Knowledge of the nutrient requirements of fungi,
phytoplankton, and filamentous algae is more ex-
tensive than for rooted aquatic plants. Laboratory
data on nutrient requirements must be used with
caution, however, because the maintenance of
most long-term cultures has required that extracts
of soil be incorporated into the inorganic culture
medium. Analyses of field grown algae have indi-
cated a wide divergence in elemental composition
among various species and among the same species
from different localities. Excessive growths often
seen to be triggered by small amounts of so-called
minor or trace elements and vitamins, particularly
B12.
One of the most obvious effects of increases or
imbalances in nutrients is the change in the kinds
and abundance of species composing the algal
flora. Historical studies of Lake Erie show a
change from an Asterionella dominance in the
spring and a Synedra dominance in the fall of
1920 to a Melosira dominance in the spring and
a Melosira, Anabaena, Oscillatoria dominance in
the fall of 1962. Between 1919 and 1934, the
number of cells per ml, with two exceptions, al-
ways were less than 4,000/ml. Since 1934, the
cell count, with one exception, has always been
greater than 4,000/ml. In 1944, it reached 11,032
cells/ml. It should be pointed out that blue-green
algae are a poor source of food for most aquatic
life.
Benthic forms also indicate the increase in nu-
trients in an ecosystem. Various species of Clado-
phora become abundant in lakes and rivers when
nutrients are abundant and replace the original
diverse benthic flora.
This demand for a wide variety of nutrients
is also characteristic of many of the rooted
aquatic plants. Their affinity for numerous metals,
however, does not appear to be comparable to
that of the algae.
Extensive data exist on the concentration of
nitrogen and phosphorus in fresh waters through-
out the United States. (Alice, et al., 1949; Ellis,
1940; Engelbrecht and Morgan, 1961; Juday,
et al., 1927; Lackey, 1945; USDHEW, 1962a)
In evaluating these data, it must be remembered
that algae and most other aquatic plants are capa-
ble of utilizing any available N and/or P in a very
short time providing other growth conditions are
favorable. Thus, analyses of filtered water would
not provide an evaluation of all elements existing
in the original water sample. A more meaningful
figure would result if all materials in an original
water sample were digested and then analyzed.
Often, the dissolved or available phosphorus may
be very low, while the total amount in the orga-
nisms and organic matter may be quite large. Not
only does this determination of total phosphorous
give a better estimate of the existing nutrient load
of an area, but it also provides an index to the
potential release that would occur if these plants
should all die within a short period of time.
This information would also point out the fact
that in many freshwaters, various species of rooted
aquatic plants are excellent receptors for this nu-
trient load. Their use in effluent treatment might
be one of the cheaper waste-treatment procedures.
The chemical composition of several species of
plants is given in table III-4. Indications are that
the N-P content of freshwaters in the United
States is quite varied, and their presence in fairly
large amounts may or may not produce algae
blooms.
It must be remembered that factors other than
plant nutrients also are operative in the establish-
ment and maintenance of aquatic plant growths.
There must be sufficient light reaching the plant
for photosynthesis to occur. If turbidity from
muds, dyes, other materials, or even phyto-
plankton is too great, plants at lower depths can-
not grow. These same plants, however, if estab-
lished in an area, can trap large amounts of
intermittent silt and other materials and clear the
waters for downstream uses.
Another factor that might be operative in pre-
venting aquatic plant growth would be the lack
of free CO2 and bicarbonate ions in a particular
54
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aquatic environment. Certainly in an area where
the pH is high (9.5 or above) or low (below 5.5),
productivity would not reach high levels due to
a lack of sufficient bicarbonates.
Temperature also is an important factor in de-
termining the amount of growth. For each species,
there is an optimum range in which the greatest
growth occurs.
Wave action on large expanses of water may
also be a factor in regulating all types of aquatic
plant growths. This appears contradictory to the
concept that winds cause mixing of surface and
bottom waters, thereby renewing plant nutrients
in the euphotic zone. However, in certain lakes
and reservoirs, wind-induced waves and currents
mechanically agitate bottom materials and waters
to an extent that interferes with the production of
phytoplankton and rooted aquatic plants.
Various workers have discussed the concentra-
tions of nitrogen and phosphorus that are needed
for an algal bloom. Sawyer (1947) suggests that
a concentration of at least 15 /ag/1 of phosphorus
is necessary for growth. Hutchinson (1957) states
that Asterionella can take up phosphorus from
where it is present at less than one ju.g/1. As a re-
sult of the study of 17 Wisconsin lakes, Mac-
kenthun (1965) cites results indicating that in-
organic nitrogen at 0.30 mg/1 and inorganic
phosphorus at 0.01 mg/1, at the start of an active
growing season, subsequently permitted algal
blooms. As yet, there is no definite information on
the amount of wastes that will produce predictable
harmful effects in a lake. There are indicators,
however, of developing or potentially undesirable
conditions.
There are several conditions, analyses, or meas-
ures that will indicate eutrophication and dystro-
phication. Since these parameters are not infallible,
it is well to use them in combinations. Conditions
indicative of organic enrichment are:
(1) A slow overall decrease year after year in
the dissolved oxygen in the hypolimnion
as indicated by determinations made a
short time before the fall overturn and an
increase in anaerobic areas in the lower
portion of the hypolimnion.
TABLE 111-4. Chemical Composition of Some Algae From Ponds and Lakes in Southeastern
United States'
Analysis
Ash percent
C percent
N percent
P percent
S percent
Ca percent
Mg percent
K percent
Na percent
Fe mg/1
Mn mg/1
Zn mg/1
Cu mg/1
B mg/1
Chara
„ 43.4
29.3
2.46
0.25
0.55
8.03
... 0.92
2.35
_ _ 0.13
2,520
2,926
89
19
6.7
Pithophora
27.77
35.38
2.57
0.30
1.42
3.82
0.20
3.06
0.07
2,836
829
29
23
65
Spirogyra
13.06
42.40
3.01
0.20
0.27
0.57
0.45
0.92
1.42
1,368
1 641
72
47
4.2
Giant
Spirogyra
13.86
41.16
2.35
0.23
0.24
0.84
0.30
099
1.43
1 793
1 658
46
34
4.3
Rhizoclonium
17.36
39.10
3.46
0.43
0.27
0.52
0.21
1.90
0.09
1 820
1 687
89
75
1 8
Oedogonium
12.69
40.84
2.64
0.08
0.15
0.44
0.16
3.03
0.06
1,645
1 729
119
75
8 1
Mougeotis
14.54
40.74
1 77
0.25
0.36
1.68
0.57
1 20
0.49
60
1 080
520
143
8
Anabaena
5.19
49.70
9.43
0.77
0.53
0.36
0.42
1.20
0.18
80
800
70
Analysis
Cladophora
Euglena
Hydrodictyon Microcystis
Lyngbya
Nitella Aphanizomenon
Ash percent
C percent
N percent
P percent
S percent
Ca percent
Mg percent
K percent
Na percent
Mn mg/1
Fe mg/1
Zn mg/1
Cu mg/1
B mg/1
23.38
._ 35.27
2.30
0.56
1.58
1.69
0.23
6.08
0.18
__ 1,040
- 2,300
10
190
84.6
4.12
48.14
5.14
0.67
0.19
0.05
0.07
0 34
0.02
240
1,545
73
290
3.8
17.94
3996
3.87
0.24
1.41
0.69
0.17
4 21
0 38
1 373
1 963
129
114
6.2
46.46
8.08
0.68
0.27
0.53
0.17
0 79
0.04
2,751
322
48
37
3.6
17.20
40 23
5.01
0.31
0.28
0.45
0.14
0.42
0 06
5 230
3 866
171
101
112
19.11
3843
2.70
0.23
0 34
1.89
0.95
3.73
0 28
2 388
2 180
240
39
9.8
7.21
47.65
8.57
1.17
1.18
0.73
0.21
0 68
0 19
167
833
120
187
1 Lawrence (personal communication).
55
-------
(2) An increase in dissolved solids—especially
nutrient materials such as nitrogen, phos-
phorus, and simple carbohydrates.
(3) An increase in suspended solids—espe-
cially organic materials.
(4) A shift from a diatom-dominated plankton
population to one dominated by blue-green
and/or green algae, associated with in-
creases in amounts and changes in relative
abundance of nutrients.
(5) A steady though slow decrease in light
penetration.
(6) An increase in organic materials and nu-
trients, especially phosphorus, in bottom
deposits.
Recommendation: The Subcommittee wishes to stress
that the concentrations set forth are suggested solely as
guidelines and the maintenance of these may or may
not prevent undesirable blooms. All the factors causing
nuisance plant growths and the level of each which
should not be exceeded are not known.
(1) In order to limit nuisance growths, the addition
of all organic wastes such as sewage, food processing,
cannery, and industrial wastes containing nutrients,
vitamins, trace elements, and growth stimulants should
be carefully controlled. Furthermore, it should be
pointed out that the addition of sulfates or manganese
oxide to a lake should be limited if iron is present in
the hypolimnion as they may increase the quantity of
available phosphorus.
(2) Nothing should be added that causes an in-
creased zone of anaerobic decomposition of a lake or
reservoir.
(3) The naturally occurring ratios and amounts of
nitrogen (particularly NO3 and NH4) to total phos-
phorus should not be radically changed by the addition
of materials. As a guideline, the concentration of total
phosphorus should not be increased to levels exceeding
100 iug/1 in flowing streams or 50 /ug/1 where streams
enter lakes or reservoirs.
(4) Because of our present limited knowledge of
conditions promoting nuisance growth, we must have a
biological monitoring program to determine the effec-
tiveness of the control measure put into operation. A
monitoring program can detect in their early stages the
development of undesirable changes in amounts and
kinds of rooted aquatics and the condition of algal
growths. With periodic monitoring such undesirable
trends can be detected and corrected by more stringent
regulation of added organics.
Toxic substances
Aquatic life too frequently is considered only
in terms of harvestable species. The fact that nu-
merous other organisms are essential to produce
a crop of fishes often is overlooked or given little
attention. To produce a harvestable crop of fish,
it is essential to have supporting plants and ani-
mals for food. Requirements are established on
the basis that the needed criteria are those that
will protect fish, the harvested crop, and the food
organisms necessary to support that crop. At this
time, it is believed that every important species
should be protected. One can appreciate that un-
important organisms may be sacrificed if the
following criteria are adopted. Fish too often
are considered as a single species instead of a
multitude of species. Many are distinctly and
greatly different from other related species and
have their own distinctive requirements. Because
of this, and because the important species, essen-
tial food organisms, and water quality will be
different in different habitats, a single value or
concentration has very limited applicability unless
appropriate margins of safety are incorporated.
For these reasons, the bioassay approach de-
scribed later in this section is favored. It is believed
that bioassays are the best method for determining
safe concentrations of toxicants for the species
of local importance. Bioassays are essential also
to determine safe concentrations for food orga-
nisms of those species and the effect of existing
water quality, including environmental variables
as well as existing pollution. Pertinent to this
stance is the fact that the majority of specific pol-
lution problems are ones involving discharges of
unknown and variable composition. Almost with-
out exception, more than one toxicant or stress is
present. Further, suggested safe concentrations
probably will not be adequate in instances where
more than one adverse factor exists. It is believed
that these recommended levels will be adequate
for a particular pollutant if dissolved oxygen,
temperature, and pH are within the limits recom-
mended. If the latter parameters are outside
recommended limits, appropriate alterations in the
criteria for toxicants must be made.
Most of the available toxicity data are reported
as the median tolerance limit (TLm), the concen-
tration that kills 50 percent of the test organisms
within a specified time span, usually in 96 hours
or less. This system of reporting has been mis-
applied by some who have erroneously inferred
that a TLm value is a safe value, whereas it is
merely the level at which half the test organisms
are killed. In many cases, the differences are great
between TLm concentrations and concentrations
that are low enough to permit reproduction and
growth.
Substantial data on long-term effects and safe
levels are available for only a few toxicants, per-
haps 10. The effect of toxicants on reproduction
is nearly unknown, yet this is a very important
aspect of all long-term toxicity tests. In chronic
tests with six different toxicants, there were three
56
-------
toxicants with which certain concentrations per-
mitted indefinite survival and normal appearance
but blocked spawning completely. Such evidence
makes estimates of safe concentrations based on
acute lethal test data alone very difficult and fre-
quently erroneous. Equally problematical is the
near-total lack of information on the sensitivity
of the various life stages of organisms. Many or-
ganisms are the most sensitive in the larval,
nymph, molting, or fry state; some may be the
most sensitive in the egg and sperm stage.
A further difficulty is encountered in recom-
mending criteria because continuous acceptable
concentrations must be lower than the intermittent
concentrations that may be reached occasionally
without causing damage. There seems to be only
one way in which to resolve this difficulty and
that is to use both maximum concentration and a
range of concentrations. It is recognized that the
extremes do limit organisms, but, within these ex-
tremes there is a range in concentration that can
be tolerated and is safe for prolonged periods of
exposure.
Average 24-hour concentrations can be deter-
mined by using a small water pump to collect 1 to
5 ml samples every minute. After 24 hours, the
sample is mixed and analyzed. The concentration
found represents the average concentration. Sam-
ples obtained this way are more reproducible and
easier to secure than the maximum instantaneous
concentration. Maximum concentrations must be
considered in the criteria, however, because an
average concentration alone could be met and yet
permit a lethal concentration to exist for a critical
period.
Bioassay
The use of some type of bioassay to determine
the toxicity of a material or waste can be the most
effective and accurate method of assessing poten-
tial danger. With these methods, no assumptions
need be made concerning the chemical structure
or form of the pollutant, nor does the investigator
have to know the constituent substances. The ef-
fects of water quality on toxicity also may be
measured. Naturally, the more that is known about
the chemical and physical behavior of a toxicant
in water, the more precise the assay can be.
While there are many types of assays, two
are in general use: (1) the static bioassay in which
the test solution is not changed during the period
of exposure, and (2) the flow-through bioassay
in which the test solution continually is renewed.
It is nearly impossible in a static test to use the
introduced test concentration for calculating TLm
values, especially for substances or wastes that are
toxic at concentrations of 1 mg/1 or less, because
the quantity taken into the test organism may be
a very large percentage of the amount contained
in the test water. A 48-hour TLm based on the
introduced concentration could give a value much
higher than the true concentration because of this
decrease in toxicant concentration. The initial test
concentration is usually not measured in static
tests because of the changing concentration.
Knowledge of the concentration of the toxicant
at the end of the test can be of value.
The static test can give useful relative measures
of toxicity for wastes of high toxicity, but for the
reason mentioned above, it should not be used
for absolute values. Less toxic substances can ie
assayed much more accurately and lethal concen-
trations can be determined with confidence. The
chemical nature of the tested substances has an
important effect on the accuracy of the results
as well. Substances that are volatile, unstable, or
relatively insoluble may not be accurately assayed
while substances having opposite properties can
be assayed more accurately.
The problem of maintaining oxygen concen-
trations suitable for aquatic life in the test chamber
can be very difficult. Insufficient oxygen may be
present in the test water volume because a BOD
or COD may consume much of the available dis-
solved oxygen and aeration or oxygenation may
degrade or remove the test material. Devices for
maintaining satisfactory dissolved oxygen in static
tests have been proposed and used with some de-
gree of effectiveness. A rather complete account of
static assays can be found in Sandard Methods
for the Examination of Water. and Wastewater,
12th edition (1965), and Doudoroff, et al.
(1951).
In the flow-through type of bioassay a device
is used to add toxicant to a flow of water and the
mixture is discharged into the test container. This
method of testing has few of the problems men-
tioned in connection with the static test and has
other advantages in addition. Its important dis-
advantage is the more complicated work of build-
ing the necessary equipment; namely, a water
supply system, metering devices, and the provision
of a large quantity of the test substance.
Its important advantages are that a predeter-
mined concentration of test material can be main-
tained, oxygen concentrations can be kept high
or be controlled, metabolites and waste products
are removed (animals can be fed), absolute rather
than relative TLm values can be obtained, and
volatile, unstable, and sparingly soluble materials
can be tested. Additionally, multifactor experi-
ments are possible in which several variables can
be controlled (pH, dissolved oxygen, carbon diox-
57
-------
ide, etc.). The constant renewal test is superior for
monitoring effluents, water supplies, or streams on
a continuous or intermittent basis and is the only
suitable method for long-term tests.
Several systems for adding the test material to
the water have been devised since this type of
bioassay has been in use. Lemke and Mount
(1963) describe a system using a controlled water
flow balanced against a chemical metering pump.
Henderson and Pickering (1963) describe a sim-
ple drip system and a controlled water flow; a
similar system is proposed by Jackson and Brungs
(1966). Both of these latter references describe
the use of fish and flowing systems as continuous
monitors. Mount and Warner (1965), Mount and
Brungs (1967), and Brungs and Mount (1967)
describe systems suitable for continuous short or
long-term tests.
Most criteria for toxic substances must be based
on a bioassay made for each specific situation.
This is dictated by the lack of information and
the wide variation in situations, species, water
quality, and the nature of the substance being
added to the water.
Most of the bioassay work on algae has meas-
ured the threshold concentrations that reduce phys-
iological processes by 50 percent rather than the
concentrations that cause 50-percent death in the
population tested. It is very difficult to determine
the death point of algae cells, but some workers
have used it as a criterion. Physiological measure-
ments have been based largely on 50-percent
reduction in photosynthesis and 50-percent reduc-
tion in number of divisions that have taken place
during a period of time. This is determined by
the number of cells present at the beginning and
end of the experiment. A bioassay method employ-
ing diatoms has been recognized by the American
Society for Testing Materials (1964).
Application Factors
Short-term or acute toxicity tests provide in-
formation on the overall toxicity of a material
and thus precede meaningful long-term toxicity
studies. They may also be used to compare toxic-
ities of different materials. When water for dilu-
tion is taken from the receiving stream, these tests
may also indicate additional stresses due to mate-
rials already present in the receiving water. These
acute studies do not indicate concentrations of a
potential toxicant that are harmless under condi-
tions of long-term exposure. It is desirable, there-
fore, to develop a factor that can be used with 96
or 48-hour TLm values to indicate concentrations
of the waste or material in question that are safe
in the receiving water. Such a factor has been
called an application factor.
Ideally, an application factor should be deter-
mined for each waste or material. To do this, it
would be necessary to determine the concentration
of the waste or material in question that does not
adversely affect the productivity of the aquatic
biota on continuous exposure, in water of known
quality, and under environmental conditions (DO,
temperature, pH, etc.) at which it is most toxic.
This concentration is then divided by the 96-hour
TLm value obtained under the same conditions
to give the application factor.
safe concentration for continuous exposure
96-hour TL™
For example, if the 96-hour TLm is 0.5 mg/1 and
the concentration of the waste found to be safe
is 0.01 mg/1, the application factor would be:
safe concentration _0.01 _ 1
96^hour TL~ ~~ 050 = 50
In this instance, the application factor is Vso or
0.02. Then in a given situation involving this
waste, the safe concentration in the receiving
stream would be found by multiplying the 96-hour
TLm by 0.02.
To effectively determine the application factor
for a given waste, it is necessary to determine the
concentration of that waste which is safe under
a given set of conditions. For those materials
whose toxicity is not significantly influenced by
water quality and in streams free of other wastes
that influence the waste in question or that have
water qualities similar to those under which the
waste was tested, the above-mentioned concen-
tration would be the one that is safe in the re-
ceiving water. However, differences in water qual-
ity and lack of information on the toxicity of
waste materials already present make the direct
use of laboratory-determined safe levels unwise
at present, and a different approach is recom-
mended.
In this approach, a 96-hour TLm is determined
for the waste using water from the receiving stream
for dilution and, as test organisms, the most sensi-
tive species or life stage of an economically im-
portant local species or one whose relative sensi-
tivity is known. This procedure would take into
consideration the effects of local quality and the
stress or adverse effects of wastes already present
in the stream. The TLm value thus found then is
multiplied by the application factor for that waste
to determine the safe concentration of that waste
in that stream or stream section. Such bioassays
should be repeated at least monthly and at each
change in process or rate of waste discharge.
This procedure must be used because of the
58
-------
extreme difference in sensitivity among species and
among necessary fish food organisms. Henderson
(1957) has discussed various factors involved
in developing application factors. Results of studies
by Mount and Stephan (1967), in which con-
tinuous exposure was used, reveal that the appli-
cation factor necessary to reduce the concentration
low enough to permit spawning ranged from l/7
to Vr,oo- It is recognized that exposure will not be
constant in most cases and that higher concentra-
tions usually can be tolerated for short periods.
At present, safe levels have been determined
for only a few wastes and hence only a few appli-
cation factors are known. Since the determination
of safe levels is an involved process, it will be nec-
essary to use indirect or stopgap procedures for
estimating tolerable concentrations of various
wastes in receiving waters. To meet this situation,
it is proposed to use three universal application
factors selected on the basis of present knowl-
edge, experience, and judgment. It is proposed
that these general application factors be applied
to TLm values determined by those discharging
wastes in the manner described above to set toler-
able concentrations of their wastes in the receiv-
ing stream.
It should be evident that when these general
application factors are used for all wastes the re-
sulting concentrations at times will be more strin-
gent than needed for some wastes and inadequate
for others. The derived concentrations will be
tolerable, however, for a considerable number of
wastes in the midrange of relative toxicity.
Recommendation for the Use of Bioassays and Appli-
cation Factors To Denote Safe Concentrations of
Wastes in Receiving Streams: (1) For the deter-
mination of acute toxicities, flow-through bioassays are
the first choice. Methods for carrying out these flow-
through tests have been described by Surber and
Thatcher (1963), Lemke and Mount (1963), Hender-
son and Pickering (1963), Jackson and Brungs (1966),
Mount and Warner (1965), Mount and Brungs (1967),
and Brungs and Mount (1967). Flow-through bio-
assays should be used for unstable, volatile, or highly
toxic wastes and those having an oxygen demand. They
also must be used when several variables such as pH,
DO, CO2 and other factors must be controlled.
(2) When flow-through tests are not feasible, tests
of a different type or duration must be used. The kinds
of local conditions affecting the procedure might be a
single application of pesticides or lack of materials and
equipment.
(3) Acute static bioassays with fish for the deter-
mination of TLm values should be carried out in ac-
cordance with Standard Methods for the Examination
of Water and Wastewater, 12th edition (1965). Such
tests should be used for the determination of TL,,, val-
ues only for persistent, nonvolatile, or highly soluble
materials of low toxicity which do not have an oxygen
demand because it is necessary to consider the amount
added as the concentration to which the test organisms
are exposed.
(4) When application factors are used with TLn,
values to determine safe concentrations of a waste in
a receiving water, the bioassay studies to determine
TLm values should be made with the most sensitive
local species and life stages of economical or ecological
importance and with dilution water taken from the
receiving stream above the waste outfall. Other species
whose relative sensitivity is known can be used in the
absence of knowledge concerning the most sensitive of
the important local species or life stages or due to
difficulty in providing them in sufficient numbers.
Alternatively, tests may be carried out using one species
of diatom, one species of an invertebrate, and two
species of fish, one of which should be a pan or game
fish. Further, these bioassays must be performed with
environmental conditions at levels at which the waste is
most toxic. Tests should be repeated with one of the
species at least monthly and when there are changes in
the character or volume of the waste.
(5) Concentration of materials that are nonper-
sistent (that is, have a half life of less than 96 hours)
or have noncumulative effects after mixing with the
receiving waters should not exceed Ho of the 96-hour
TL,,, value at any time or place. The 24-hour average
of the concentration of these materials should not
exceed l/>o of the TL,,, value after mixing. For other
toxicants the concentrations should not exceed %o and
Hoo of the TLm value under the conditions described
above. Where specific application factors have been
determined, they will be used in all instances.
When two or more toxic materials whose effects are
additive are present at the same time in the receiving
water, some reduction in the permissible concentrations
as derived from bioassays on individual substances or
wastes is necessary. The amount of reduction required
is a function of both the number of toxic materials
present and their concentrations in respect to the de-
rived permissible concentration. An appropriate means
of assuring that the combined amounts of the several
substances do not exceed a permissible concentration
for the mixture is through the use of following rela-
tionship:
Where C.,, G,, . . . G, are the measured concentra-
tions of the several toxic materials in the water and
L,, Lb, . . . Ln are the respective permissible concen-
tration limits derived for the materials on an individual
basis. Should the sum of the several fractions exceed
one, then a local restriction on the concentration of
one or more of the substances is necessary.
Heavy Metals
An extensive discussion of the physiological
mode of action of heavy metals is found in the
toxicity portion of the section on water quality re-
quirements for marine organisms.
Zinc: While much information has been pub-
lished regarding zinc, a large amount of the data
cannot be used because of incomplete description
59
-------
of methods, type of water, or concentrations. The
authors of many of the papers dealing with zinc
toxicity have used various specific sublethal effects
as endpoints and there is no way to compare these
findings with other work.
Since the concentration of calcium and mag-
nesium influences heavy metal toxicity, permissible
levels of heavy metals are dependent on the cal-
cium and magnesium concentrations. Certain stud-
ies with zinc (Mount, 1966; and unpublished work
of the FWPCA National Water Quality Lab., Du-
luth, Minn.) and cadmium indicate that for a
given calcium and magnesium concentration the
acute toxicity of zinc and cadmium increases
(TLm concentration decreases) as pH is raised
from 5 to 9. This seems contrary to prevalent
opinion that metal toxicity is related to metal in
solution and that as pH increases (solubility de-
creases) the toxicity decreases. The reason for this
apparent contradiction is that conceptions con-
cerning the effect of pH are based on natural
waters in which pH does not vary independently
of calcium and magnesium concentrations, but
rather is closely related to it. In those cases where
this relationship has been studied, except for one
(Sprague, 1964b), the toxicity has increased with
an increase in pH. This concept also is consistent
with the work of Lloyd (1961b) and, more re-
cently, that of Herbert and Wakeford (1964) who
concluded that colloidal or flocculated, but sus-
pended, zinc exerts a toxic influence on fish.
The significance of temperature and the cal-
cium-magnesium content on the toxicity of zinc
to plankton has been pointed out by Patrick (un-
published data). In these tests, a 50-percent re-
duction in growth of the population was used as
a measure. Results of these tests are summarized
as follows:
Concentration in mg/l which reduces
growth of population by 50 percent
Temperature of
lest solution
Ca-Mg concentra-
tion—44 mg/l as
CaCO, Nitzchia
linearis
Ca-Mg concentra-
tion—170 mg/l as
CaCOs Navicula
seminulum
72 F 4.29 mg/l 4.05 mg/I.
82 F 1.59 mg/l 2.31 mg/l.
86 F 1.32 mg/l 3.22 mg/l.
Palmer (1957) found that zinc dimethyl dithio-
carbamate (ZDD) inhibited growth of Micro-
cystis at 0.004 mg/l. A concentration of 0.25 mg/l
controlled all diatoms, 43 percent of the blue-
green algae, and 18 percent of the green algae.
The above evidence implies that permissible levels
of zinc cannot be related to the calcium-magne-
sium concentrations or to pH alone.
Herbert and Wakeford (1964) described the
effect of salinity on the toxicity of zinc to rain-
bow trout. Since zinc was most toxic to trout in
freshwater, it is assumed that concentrations which
are safe in freshwater will be safe for the salmonids
in brackish water. The maximum reported affect
of a reduction of dissolved oxygen from 6-7 mg/l
to 2 mg/l on the acute toxicity of zinc is a 50-
percent increase in its acute toxicity (Lloyd,
1961 a; Pickering, in press; Cairns and Scheier,
1958a). Since 4 mg/l is the minimum permitted,
this effect is small in comparison to the differ-
ence between safe and acutely toxic concentra-
tions. The use of an application factor, there-
fore, should provide adequate protection. Simi-
larly, Herbert and Shurban (1963a) found that
the 24-hour TLm for zinc was reduced only 20
percent for rainbow trout forced to swim at 85
percent of their maximum sustained swimming
speed.
The effect of calcium and magnesium con-
centrations on the toxicity of zinc for plankton,
invertebrates, fishes, and their embryonic stages
is reflected in the spread of values reported as
toxic by many sources (Anderson 1950; Brungs,
in press; Cairns and Scheier 1957, 1958b; Grande,
1966; Herbert and Shurben, 1963a, b; Jones,
1938; Lloyd, 1961b; Patrick, personal communi-
cation; Pickering, in press; Pickering and Hender-
son, 1966a; Pickering and Vigor, 1965; Skid-
more, 1964; Sprague, 1964a, b; Sprague and
Ramsey, 1965; Williams and Mount, 1965; and
Wurtz, 1962).
Recommendation: The relationship between calcium
and magnesium concentration, pH, and zinc toxicity is
confusing and the separate effects have been little
studied. Brungs (in press) has determined that Hoo of
the 96-hour TLm value is a safe concentration for con-
tinuous exposure.
Copper: The same general considerations apply
to the determination of safe levels of copper as
apply to safe levels for zinc and the discussion of
copper will be based on the same assumptions.
From the published data, differences in species
sensitivity to copper appear to be somewhat greater
than for zinc (Anderson, 1950; Grande, 1966;
Herbert and Vandyke, 1964; Jones, 1938; Lloyd,
1961b; Mount, in press-; Pickering and Hender-
son, 1966a; Sprague, 1964a, b; Sprague and
Ramsey, 1965; Trama, 1954; Turnbull, DeMann,
and Weston, 1954). Mount (in press) has found
that Y30 of the 96-hour TLm value is a safe concen-
tration for continuous exposure of fish.
Bringmann and Kuhn (1959a, b) report that
0.15 mg/l copper is the threshold concentration
which produces a noticeable effect on Scenedes-
mus. Maloney and Palmer (1956) report that 0.5
60
-------
mg/1 copper as copper sulfate produces the fol-
lowing percents of death in algae:
57 percent in 17 species of blue-green algae.
35 percent in 17 species of green algae.
100 percent in 6 species of diatoms.
Fitzgerald, Gerloff, and Borg (1952) report that
0.2 mg/1 of copper (as copper sulfate) produces
a 100-percent kill of Microcystis aeruginosa.
Crance (1963) found 0.05 mg/1 kills Microcystis.
Hassall (1962), working with Chlorella vulgaris
found that 25 g/1 of copper sulfate did not in-
hibit respiration if cultures were shaken. If shaking
stopped, concentrations greater than 250 mg/1
were toxic. Preliminary experiments indicate that
lack of air increases toxicity of copper. Hale
(1937)—according to Jordan, Day, and Hendrix-
son (1962)—reported that the following concen-
trations were necessary to control the indicated
algae:
0.5 mg/1—Cladophora.
0.1 mg/1—Hydrodiclyon.
0.12 mg/1—Spirogyra.
0.20 mg/l—Ulothrix.
Calcium and magnesium concentrations are usu-
ally not given for algal tests, but it would seem
that the concentrations deemed safe for fish
would also be acceptable for plankton.
Recommendation: The maximum copper (expressed
as Cu) concentration (not including copper attached
to silt particles or in stable organic combination) at
any time or place should not be greater than Ho the
96-hour TLm value, nor should any 24-hour average
concentration exceed V&0 of the 96-hour TLm value.
Cadmium: Few studies have been made of the
toxicity of cadmium in the aquatic environment.
Mammalian studies have shown it to have sub-
stantial cumulative effects. Permissible levels in
drinking water are 0.01 mg/1 (USDHEW,
1962b), and concentrations of a few /ug/g in
food (McKee and Wolf, 1963) have caused
sickness in human beings. Mount (1967) found
accumulations in living bluegills as high as 100
Aig/g (dry weight) and in the gills of dead catfish
up to 1000 jag/g. Little accumulation was found
in the muscle. Consideration should be given to
acceptable residue levels in fish when establishing
cadmium criteria.
Daphnia appears to be very sensitive to cadmium
(Anderson, 1950). Bringmann and Kuhn (1959a)
indicate Scenedesmus, and Escherichia coli are
about equally sensitive. Data as yet unpublished
(Pickering, in press) reveal that following pro-
longed exposure there is a large accumulation of
cadmium in fish. Even though very little data are
available yet, the evidence warrants a more re-
strictive requirement for cadmium than specified
under the general bioassay section.
Recommendation: The concentration of cadmium
must not exceed '/ijo of the 96-hour TLm concentration
at any time or place and the maximum 24-hour average
concentration should not exceed %oo of the 96-hour
TLm concentration.
Hexavalent Chromium: The chronic toxicity
of hexavalent chromium to fish has been studied
by Olson (1958) and Olson and Foster (1956,
1957). Their data demonstrate a pronounced
cumulative toxicity of chromium to trout and sal-
mon. Mr. P. A. Olson (personal communication)
of Battelle Memorial Institute advises that some
recent comparisons of 48 and 96-hour TLm con-
centrations with concentrations not adversely af-
fecting the same species indicate that the applica-
tion factor for hexavalent chromium is x%00,000
for salmon and %00,000 f°r rainbow trout. He
also feels however, that such factors are not valid
for carp. Doudoroff and Katz (1953) found that
bluegills tolerated a 45 mg/1 level for 20 days in
hard water. Cairns (1956), using chromic oxide
(CrO3), found that a concentration of 104 mg/1
was toxic in 6 to 84 hours. Daphnia and Micro-
regma exhibit threshold effects at hexavalent
chromium levels of 0.016 to 0.7 mg/1.
Some data are available concerning the toxicity
of chromium to algae. The concentrations of chro-
mium that inhibit growth (Hervey, 1949) for the
test organisms are as follows: Chlorococcales, 3.2
to 6.4 mg/1; Euglenoids, 0.32 to 1.6 mg/1; and
diatoms, 0.032 to 0.32, mg/1. Chromium at sub-
lethal doses sometimes stimulates algae. Patrick
(unpublished data) has studied the effects of tem-
perature on the toxicity of chromium to certain
algae. Her findings on the concentrations which re-
duce population growth by 50 percent are as fol-
lows:
Nitzschia linearis.—50 percent reduction in
growth of population as compared with control
(soft water 44 mg/1 Ca-Mg as CaCO,)
22 C—0.208 mg/1 Cr
28 C—0.261 mg/1 Cr
30 C—0.272 mg/1 Cr
Navicula seminulum var. hustedtii (hard water
170 mg/1 Ca-Mg as CaCO3)
22 C—0.254 mg/1 Cr
28 C-^0.343 mg/1 Cr
30 C—0.433 mg/1 Cr
Recommendation: Data are too incomplete to do more
than urge caution in the discharge of chromium. Con-
centrations of 0.02 mg/1 in soft water have been found
safe for salmonid fishes.
61
-------
TABLE III-5A. Pesticides *
INSECTICIDES
[48-hour TLm values from static bioassay, in micrograms per liter. Exceptions are noted.]
Pesticide
Abate
Aldrin 5
Allethrin
Azodrin
Aramite
Baveon 5
Baytex 5 _
Benzene hexachloride
(lindane).
Bidrin _
Carbaryl (sevin)
Carbophenothion
(trithion).
Chlordane 5 _ _ _
Chlorobenzilate
Chlorthion
Coumaphos
Cryolite
Cyclethnn
ODD (IDE) 8 - _
DDT5 . _ _ -
Delnav (dioxathion) _.
Delmeton (systex)
Diazinon ^
Dibrom (naled)
Dieldrin 5
Dilan _ _
Dimethoate
(cygon).
Dimethrin
Dichlorvos5 (DDVP) ..
Stream invertebrate 1
Species TLm
Pteronarcys _
caiifornica.
P. caiifornica
P. caiifornica
-P caiifornica
P caiifornica
P. caiifornica
P caiifornica
-P caiifornica
-P caiifornica
p caiifornica
-P caiifornica
P. caiifornica
-P ralifornira
Disulfoten (di-syston)__p caiifornica
Dursban . -Potarnnaroella
Endosulfan (thiodan) _
Endrin "
EPH .
Ethion
Ethyl guthion E
Fenthion
Guthion 5
Heptachlor 6
Kelthane (dicofel)
Kepone _ _
Malathion 5
Methoxychlor B
Methyl parathion 5
Morestan
Ovex
Paradichlorobenzene
Parathion 5
Perthane
Phosdrin 5
Phosphamidon
Pyrethrins
Rotenone
Tetradifon (tedion) __.
TEPP5
Thanite
Thimet
Toxaphene 5
Trichlorofon
(dipterex).6
Zectran
badia
-P. caiifornica
, p badia
P caiifornica
P badia
_P caiifornica
P caiifornica
P caiifornica
P caiifornica
P. caiifornica
P. caiifornica
P caiifornica
P caiifornica
P caiifornica
P caiifornica
P badia
P caiifornica
100
8
28
110
130
8
1,900
1.3
55
1,100
19
60
16
1.3
140
10
18
1.8
5.6
0.8
14
39
8
4
3,000
6
8
40
1,500
11
9
460
64
900
7
7
22
16
Cladocerans -
Species TLm
Daphnia
pulex.
D pulex
D. magna
Simocephalus
serrulatus.
D. pulex
D. pulex
D. pulex
D. magna
S. serrulatus
S. serrulatus
D magna
D. magna
D. pulex
D. magna
D pulex
D pulex
D pulex
D pulex
D pulex
D. magna
D. magna
D. pulex
D. magna
D. magna
D. magna
D pulex
D pulex
D magna
D. pulex
D magna
D. pulex
D. pulex
D. magna
D. pulex
D. magna _
D. pulex
D. magna
D. pulex
D. pulex
D. magna
D. pulex .
D. magna
D pulex
28
21
345
3.1
460
600
6.4
0.009
20
550
4 5
1
5,000
55
3.2
0.36
14
0.9
3.5
240
21
2,500
0.07
240
20
0.1
0.01
4
0.2
42
390
1.8
0.8
4.8
0.4
9.4
0.16
4
25
10
450
15
8.1
10
Fish 3
Species
Brook trout-
Rainbow
trout.
do
do
Bluegill
Fathead
Brown t.'
Rainbow t
do
Brown t.
Bluegill
Rainbow t
do
Rainbow t
Bass
Bluegill
do
do
Brook t.
Bluegill
do
do
Rainbow t
Bluegill .
do
Rainbow t.
do
Bluegill
do
do
Rainbow t.
Rainbow t
do
do
do
Brook t.
Rainbow t
Bluegill _ _
do
do
Rainbow t.
Bluegill
Rainbow t
do
do
do
Bluegill -
Rainbow t
Bluegill
Fathead
Bluegill _
Rainbow t
do .
do _ _
Gammarus
lacustris,4
TLm TLm
1,500
3
19
7,000
35
25
80
18
8,000
1,500
225
10
710
47,000
9
2.1
14
81
30
78
3.4
16
9,600
700
700
40
20
1.2
0.2
17
230
10
9
100
37.5
19.5
7.2
8,000
96
700
880
47
7
17
8,000
54
22
2.5
1,100
390
5.5
2.8
160
8,000
640
12,000
20
100
50
70
88
790
22
28
80
0.14
1.8
2.1
690
500
160
1,000
600
400
1
70
0.4
64
4.7
36
3.2
0.3
100
1.8
1.3
6
310
3.8
18
350
140
52
70
70
60
76
* See notes following Table Ill-SB.
62
-------
Pesticides
A general description of the use and the effects
of pesticides on aquatic life is given in the marine
section. Basically, their effects are similar in both
the marine and fresh water environments.
The addition of any persistent chlorinated
hydrocarbon pesticides is likely to result in dam-
age to aquatic life. Therefore, as concentrations
of these chemicals increase in the aquatic environ-
ment, progressive damage will result. The acute
effects usually will be recognized, but the chronic
consequences may not be observed for some time.
The use of other kinds of chemical pesticides in
or around fresh waters may produce a variety of
acute and chronic effects on fish and the other
components of the biota. Because these other
chemicals are usually not as persistent as the
chlorinated hydrocarbons, the Subcommittee feels
some of them can be used around water, but only
in amounts below those that produce chronic dam-
age to desirable species.
Recommendation: (1) Chlorinated hydrocarbons.—
Since any addition of persistent chlorinated hydro-
carbon insecticides in likely to result in permanent
damage to aquatic populations, their use should be
avoided.
(2) Other chemical pesticides.—Addition of other
kinds of chemicals used as insecticides, herbicides,
fungicides, defoliants, acaracides, algicides, etc., can
result in damage to some organisms. Table III-5 lists
the 48-hour TL,,, values for a number of pesticides for
various types of fresh water organisms. To provide
reasonably safe concentrations of these materials in
receiving waters, application factors ranging from Ho
to %oo should be used with these values depending on
the characteristic of the pesticide in question and used
as specified earlier in the section on application factors.
Concentrations thus derived tentatively may be con-
sidered safe under the environmental conditions rec-
ommended.
Other Toxic Substances
Detergents and Surfactants: The toxicity of
ABS has been reported by many workers. A wide
range of endpoints have been used as criteria and
while comparison is difficult, a reasonable conclu-
sion is possible. There is no agreement on the
effect of calcium and magnesium concentration.
Recommendations are based on the data from
table III-6.
Recommendation: With continuous exposure, the con-
centration of ABS should not exceed % of the 48-
hour TLn, concentration. Concentrations as high as
1 mg/1 may be tolerated infrequently for periods not
exceeding 24 hours. ABS may increase the toxicity
of other materials.
Much less work has been done on LAS, a
newer, degradable detergent, than on ABS. Bar-
dach, Fujiya, and Holl (1965) report that 10 mg/1
is lethal to bullheads and 0.5 mg/1 will erode 50
percent of the taste buds within 24 days. For fat-
head minnow fry, Pickering (1966) reports a
9-day TLm of 2.3 mg/1. Thatcher and Santner
(1967) report 96-hour TLm values from 3.3 to
6.4 mg/1 for five fish species. Swisher, O'Rourke,
and Tomlinson (1954), testing bluegills, found
TLm values of 3 mg/1 for LAS and 12 carbon
homologs and 0.6 mg/1 for 14 other carbon homo-
logs. An intermediate degradation product had a
TLm of 75 mg/1. Dugan (1967) found that sensi-
tivity to chlorinated pesticides possibly increased
after exposure to detergent. Other studies as yet
unpublished indicate a surprising increase in tox-
icity at low dissolved oxygen concentrations.
Pickering and Thatcher (in press), in the only
reported study on reproduction, found that 0.6
mg/1 had no measurable effect on reproduction or
growth but 1.1 mg/1 had an effect. In tests with
five species of fishes. Thatcher and Santner
(1967) found two species which were more sensi-
tive to LAS than fathead minnows.
With both ABS and LAS detergents, the more
readily degradable components are the more toxic.
As a result, the components remaining will be less
toxic than the original product.
Recommendation: The concentration of LAS should
not exceed 0.2 mg/1 of V? of the 48-hour TL,,, con-
centration, whichever is the lower.
Cyanide: Although it has been studied exten-
sively, cyanide is not well understood as a hazard
to aquatic life. Certain unique and peculiar char-
acteristics necessitate special treatment of this
chemical even though acceptable concentrations
cannot be given.
Recent work on fish by Doudoroff et al. (1966),
has demonstrated that HCN rather than CN is the
toxic component. Except for certain extremely
toxic heavy metals (silver, for example) the tox-
icity of metallo-cyanide complexes can also be
attributed to the HCN. This then makes the effect
of pH on cyanide toxicity of great importance.
Doudoroff (1956) demonstrated a thousandfold
increase in the toxicity of a nickelo-cyanide com-
plex associated with a drop in pH from 8.0 to 6.5.
A change in pH from 7.8 to 7.5 increases the tox-
icity ten times. The data reported by Cairns and
Scheier (1963b) indicate that the calcium-mag-
nesium concentrations (hardness) do not mate-
rially affect cyanide toxicity. It should be noted
that in their test solutions while the calcium-
magnesium concentration of their soft and hard
63
-------
TABLE Ill-SB. Pesticides, cont.
HERBICIDES, FUNGICIDES, DEFOLIANTS, ALGICIDES
Pesticide
Ametryne
Aminotriazole
Aquathol
Atrazine
Azide, potassium
Azide sodium
Copper chloride
Copper sulfate
Dichlobenil
2 4-D PGBEE
24-D BEE
2 4-D isopropyl
2 4-D butyl ester
2,4-D, butyl +
isopropyl ester.
2,4,5-T isooctyl ester
2,4, 5-T isopropyl ester.
2,4,5-T PGBE
2(2,4-DP) BEE
Dalapon
Dead-X
DEF -
Dexon _ _ __ ._
Dicamba
Dichlone
Difolitan
Dinitrocresol
Diquat
Diuron
Du-ter
Dyrene _ ._ __ „
Endothal, copper
Endothal,
dimethylamine.
Fenac, acid
Fenac, sodium
Hydram (molinate) ___
Hydrothol 191
Lanstan (korax)
LFN
Paraquat
Propazine
Silvex, PGBEE
Silvex, isoctyl
Silvex, BEE .__
Simazine _
Sodium arsenite
Tordon (picloram)
Trifuralin
Vernam :' (vernolate)
Stream invertebrate 1
Species TLm
Pteronarcys 44 000
californica.
P. californica 1,800
P californica
Very low toxicity
P californica 5,000
P. californica 2,300
P. californica 42,000
P californica 150
P californica 560
P. californica 2,800
P californica 70 000
P. californica 80,000
_P. californica 3,500
P californica
Very low toxicity
P. californica 50,000
P. californica
Very low toxicity
P californica 4 200
Cladocerans 2
Species TLm
Daphnia
magna.
Daphnia
pulex.
D. pulex _
D. magna
D. pulex
D. magna
D. pulex
D. magna
D. pulex
D pulex
D pulex
Simocephalus
serrulatus.
D pulex
3,600
3,700
3,200
6,000
3,700
26
1,400
490
4,500
3,700
2,000
1,400
240
Fish "
Species
Rainbow t.
Bluegill
Rainbow t.
Bluegill
do
do
do
do
Rainbow t
Bluegill
do
do
do
do
do
do
do
Rainbow t
Bluegill
Bluegill __
non-tox.
Rainbow t
Channel Cat-
Rainbow t
do
do
Bluegill
Rainbow t
do
do
do
do
do _ . _
do
do
Very low
toxicity.
Rainbow t
do
Bluegill
do
Rainbow t.
do
do _ _
do
do
TLm
3,400
257
12,600
1,400
980
1,100
150
20,000
960
2,100
800
1,300
1,500
16,700
1,700
560
1,100
Very
9,400
36
23,000
48
31
210
12,300
4,300
33
15
290
1,150
16,500
7,500
290
690
100
79
7,800
650
1,400
1,200
5,000
36,500
2,500
11
5,900
Gammarus
lacustris,1
TLm
10,000
9,000
1,500
1,800
760
Low toxicity.
5,600
230
6,000
5,800
11,500
6,500
380
18,000
1,000
5,500
18,000
21,000
48,000
5,600
25,000
1 Stonefly bioassay was done at Denver, Colo., and at Salt
Lake City, Utah Denver tests were in soft water (35 mg/l IDS),
non-aerated, 60 F. Salt Lake City tests were in hard water (150
mg/l TDS), aerated, 48-50 F. Response was death.
2 Daphnia pulex and Simocephalus serrulatus bioassay was
done at Denver, Colo., in soft water (35 mg/l TDS), non-aerated,
60 F. Daphnia magna bioassay was done at Pennsylvania State
University in hard water (146 mg/l TDS), non-aerated, 68 F.
Response was immobilization.
3 Fish bioassay was done at Denver, Colo., and at Rome, N.Y.
Denver tests were with 2-mch fish in scft water (35 mg/l TDS),
non-aerated; trout at 55 F; other species at 65 F. Rome tests
were with 2-2>/2-inch fish in soft water (6 mg/l TA: pH 5.85-
6.4), 60 F. Response was death.
4 Gammarus bioassay was done at Denver, Colo., in soft
water (35 mg/l TDS), non-aerated, 60 F. Response was death.
5 Becomes bound to soil when used according to directions,
but highly toxic (reflected in numbers) when added directly to
water.
64
-------
water was greatly different, the pH and toxicity
were similar.
Burdick and Lipschuetz (1950) show that some
metallo-cyanide complexes decompose in sunlight
and become highly toxic due to release of cyanide
from the complex. Cairns and Scheier (1963b)
found some increase in toxicity at reduced oxygen
concentrations and Henderson, et al. (1961)
demonstrated marked cumulative toxicity of an
organic cyanide in 30-day tests.
The toxicity of cyanide to diatoms varied little
with change of temperature and was a little more
TABLE 111-6. Effect of Alkyl-Aryl Sulfonate, Including ABS, on Aquatic Organisms
Organisms
Concentration (mg/l)
Time
Effect
References
Trout 5.0
3.7
5.0
Bluegills 4.2
3.7
0.86
16.0
5.6
17.0
Fathead minnows 2.3
13.0
11.3
Fathead minnow fry 3.1
Pumpkinseed sunfish 9.8
Salmon 5.6
Yellow bullheads 1.0
Emerald shiner 7.4
Bluntnose minnow 7.7
Stoneroller 8.9
Silver jaw 9.2
Rosefin 9.5
Common shiner 17.0
Carp 18.0
Black bullhead 22.0
"Fish" 6.5
Trout sperm 10.0
Daphma 5.0
20.0
7.5
Lirceus fontmalis 10.0
Crangonyx setodactylus1
Stenonema ares
Stenonema heterotarsale
Isonychia bicolor
Hydropsychidae (mostly
cheumatopsyche).
Orconectes rusticus __-
Goniobasis livescens _.
10.0
8.0
16.0
8.0
16.0
8.0
16.0
32.0
16.0
32.0
16.0
32.0
18.0
24.0
Chlorella 3.6
Snail
Nitzchia linearis 5.8
Navicula seminulum 23.0
26 to 30 hours Death Wurtz-Arlet, 1960.
24 hours TU
Gill pathology Schmid and Mann, 1961.
24 hours ~ ~_.TU Turnbull, et al., 1954.
48 hours TLm
Safe
30 days TLm Lemke and Mount, 1963.
90 days Gill damage Cairns and Scheier, 1963.
96 hours TLm
Reduced spawning ...Pickering, 1966.
96 hours TU Henderson, et al., 1959.
96 hours TU, Thatcher, 1966.
7 days TU Pickering, 1966.
3 months Gill damage Cairns and Scheier, 1964.
3 days Mortality Holland, et al., 1960.
10 days Histopathology Bardach, et al., 1965.
96 hours _ . , -TU Thatcher, 1966.
96 hours TU Thatcher, 1966.
96 hours TU Thatcher, 1966.
96 hours TU Thatcher, 1966.
96 hours TU Thatcher, 1966.
96 hours . TU Thatcher, 1966.
96 hours _ _ TU Thatcher, 1966.
96 hours TU Thatcher, 1966.
Min. lethality Leclerc and Devlaminck,
1952.
Damage Mann and Schmid, 1961.
96 hours TU Sierp and Thiele, 1954.
24 hours TU Godzch, 1961.
96 hours TU Godzch, 1961.
14 days 6.7 percent survival Surber and Thatcher, 1963.
(hard water).
14 days 0 percent survival Surber and Thatcher, 1963.
(hard water).
10 days 20-33 percent Surber and Thatcher, 1963.
survival.
10 days 0 percent survival Surber and Thatcher, 1963.
10 days 40 percent suryival___Surber and Thatcher, 1963.
10 days 0 percent survival Surber and Thatcher, 1963.
9 days 0 percent survival Surber and Thatcher, 1963.
12 days 37-43 percent Surber and Thatcher, 1963.
survival.
12 days 20 percent survival...Surber and Thatcher, 1963.
9 days 100 percent survival..Surber and Thatcher, 1963.
9 days 0 percent survival Surber and Thatcher, 1963.
12 days 40-80 percent Surber and Thatcher, 1963.
survival.
12 days 0 percent survival Surber and Thatcher, 1963.
96 hours TU Cairns and Scheier, 1964.
96 hours TU Cairns and Scheier, 1964.
Slight growth Maloney, 1966.
reduction.
50 percent reduc- Cairns, etal., 1964.
tion in growth
in soft water.
50 percent reduc- Cairns, etal., 1964.
tion in growth
in soft water.
1 Misrdentified originally as Synurella.
65
-------
toxic in soft water than in hard water (Patrick,
unpublished data). For Nitzchia linearis a 50-per-
cent reduction in growth of the population in soft
water (44 mg/1 Ca-Mg as CaCO3) occurred as
follows: 0.288 mg/1 (CN) at 72 F, 0.295 mg/1 at
82 F, and 0.277 mg/1 at 86 F. For Navicula semi-
nulum var. hustedtii, the concentrations that re-
duced growth of the population 50 percent in hard
water (170 mg/1 Ca-Mg as CaCO3) were as fol-
lows: 0.356 mg/1 at 72 F, 0.491 mg/1 at 82 F,
and 0.424 mg/1 at 86 F.
Recommendation: Permissible concentrations of cy-
anide should be determined by the flow-through bio-
assay method described in the bioassay section. These
tests should be conducted with DO, temperature, and
pH at recommended levels for the factors under which
the cyanide (HCN) is most toxic or under local water
conditions at which it is the most toxic.
Ammonia: The toxicity of ammonia has been
studied by several investigators but because of in-
adequate reporting and unsatisfactory experi-
mental control, much of the work is not usable.
Doudoroff and Katz (1950), Wuhrmann, et al.
(1947), and Wuhrmann and Woker (1948) give
a complete account of the pH effect on ammonia
toxicity and demonstrate that toxicity is dependent
primarily on undissociated NH4OH and nonionic
ammonia. They found no obvious relationship be-
tween time until loss of equilibrium and total
ammonium content. They also demonstrated a
striking synergy between ammonia and cyanide.
McKee and Wolf (1963) state that toxicity is in-
creased markedly by reduced dissolved oxygen.
Field studies by Ellis (1940) and other observa-
tions lead to the conclusion that at pH levels of 8.0
and above total ammonia expressed as N should
not exceed 1.5 mg/1. It has been found that
2.5 mg/1 total ammonia expressed as N is acutely
toxic.
Recommendation: Permissible concentrations of am-
monia should be determined by the flow-through bio-
assay with the pH of the test solution maintained at
8.5, DO concentrations between 4 and 5 mg/1, and
temperatures near the upper allowable levels.
marine
and estuarine
organisms
Others: Especially significant sources of wastes
that must be considered individually are derived
from tar, gas, and coke-producing plants, pulp
and paper mills, petroleum refining and petro-
chemical plants, waterfront boating activities, and
special-purpose laboratories. These problems are
discussed in the toxicity portion of the section on
water quality requirements for marine organisms.
66
-------
ESTUARIES are recognized as being of critical
importance in man's harvest of economically
useful living marine resources. It is in these areas
that the maximum conversion of solar energy into
aquatic plant life takes place and they are justly
identified as "nurseries" since so many animals
utilize them for feeding their early life stages. Some
species, such as the oyster, spend their entire life
span in the estuary, while the shrimp and men-
haden reside there only as juveniles. The salmon
and a few others use the estuary primarily as a
pathway. In sum, however, more than half of the
over 4.5 billion pounds of fishery products har-
vested by U.S. fisherman annually is derived from
animals dependent for their existence on clean
estuarine waters during some part or all of their
life cycle.
Pollution of estuarine and coastal waters is diffi-
cult to assess because of the special qualities of
this environment. Technically, any foreign sub-
stance or environmental condition that inter-
feres with a desired use may be considered a pol-
lutant, but we are concerned with those substances
present at high enough concentrations or en-
vironmental changes great enough to cause de-
leterious effect. Many naturally occurring sub-
stances in salt water become toxic when their
concentrations are increased artificially or by
natural processes.
The problem in establishing criteria in estuaries
arises from the fluctuating nature of the water
quality, both daily and seasonally, and geograph-
ically within the estuary. Changes in salinity, pH,
turbidity, and temperature may alter greatly the
critical toxic concentration of a pollutant. Most
chlorinated hydrocarbon pesticides, for example,
are significantly more acutely toxic at summer
rather than winter water temperatures and at least
one of the common detergents becomes decidedly
more toxic to fish as salinity levels increase.
The most obvious effect of tidal action in the
estuary is to change water depth. This indirectly
changes current patterns, water temperature, and
the density of motile animal populations. Depend-
ing on the geography of the estuary and the
amount of fresh water drainage into it, salinity
patterns may vary from relatively uniform condi-
tions throughout a tidal cycle to situations in
which the> water is clearly stratified with a layer of
relatively fresh water overlying the bottom salt
water, or to situations in which the major portion
of the water mass changes from fresh to salt and
back to fresh again.
In shallow, broad estuaries, wind may be the
dominant factor in causing water movements
which change salinity and temperature patterns.
The volume of fresh water discharged into an
estuary may be a major factor in establishing
coastal currents that transport pollution loads from
one region to another.
We are dealing, then, with an environment in
which the characteristics of the receiving water are
usually fluctuating, frequently unexpectedly. As a
result, its ability to dilute and disperse a burden of
toxicants is unpredictable without detailed local
investigations.
Pollution in the estuary may be derived from
contamination hundreds of miles upstream in the
river basin or it may be of purely local origin. Silt
plays a major role in the transport of toxicants,
especially pesticides, down to the estuary. Agri-
cultural chemicals are adsorbed on silt particles.
Under poor farming practices, as much as 11 tons
of silt per acre per year may be washed by surface
water into a drainage basin. Surface mining and
deforestation further accelerate the process of ero-
sion and permit the transport of terrestrial chemi-
cal deposits to the marine environment.
Atmospheric drift is also an important factor in
the transport of pollutants to the aquatic environ-
ment (Cohen and Pinkerton, 1966). Much of the
tonnage of aerially applied pesticides fails to reach
the designated spray areas and the presence of
5 /ug/1 of DDT in presumably untreated Alaskan
rivers indicates the magnitude of this facet of the
pollution problem. The continuous presence of
5 /Ag/1 of DDT in the marine environment would
decrease the growth of oyster populations by
nearly 50 percent.
Toxic pollutants may be passed directly into
the marine environment as contaminants of in-
dustrial and domestic waste effluents or they may
be intentionally placed there as in the control of
various noxious insects by spraying marsh and
littoral habitats with synthetic pesticides. Experi-
mentally, some synthetic insecticides have been
applied directly to estuarine bottoms in efforts to
control oyster pests.
Finally, there are naturally occurring substances
such as lignins and phosphate compounds which
in times of flood may be carried to the estuary in
sufficient quantity to constitute a pollution hazard.
Salinity
The spatial and temporal distribution of salinity
profoundly affects the activities of many estuarine
species in tidal tributaries (Andrews, 1964; Emery
and Stevenson, 1957; Hargis, 1965 and 1966;
Pearse and Gunter, 1957; Pritchard, 1953). Some
bottom organisms, e.g., Crassostrea virginica, are
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able to survive lower salinities than can their
predators and disease-causing organisms. Hence,
in some tidal tributaries, oysters thrive in regions
where they are sheltered from these pests by low
salinity. Natural alterations in salinity distribution
have been reportedly followed by increased mor-
tality of oysters. It is clear that care must be
exercised in the approval of engineering projects
or industrial processes that will alter salinity re-
gimes in tidal tributaries and lagoons and in their
associated wetlands.
Salinity patterns can be caused to vary from
"normal" by alterations in character of freshwater
inflow and basin geometry. These are the same
factors that produce changes in circulation. In fact,
salinity alterations are precursors to changes in
density currents.
Recommendation: For the protection of estuarine
organisms, no changes in channels, in the basin geom-
etry of the area, or in fresh water inflow should be
made that would cause permanent changes in isohaline
patterns of more than ±10 percent of the natural
variation.
Currents
Despite their large volumes, tidal waters, espe-
cially those in tributaries of the seas, have special
circulatory characteristics that may affect their
ability to assimilate wastes. For example, tidal ac-
tion slows the already slowed (due to lowered
slope and resulting reduced speed of gravity-in-
duced flow) seaward movement of water in tidal
rivers and streams. This alternate up and down
stream movement of the water in the freshwater
portion of the tidal tributary is confounding
enough in itself (Ketchum, 1950 and 1951; Stom-
mel, 1953a, b) but in the estuarine reach, the area
where sea salts are noticeable, further complexi-
ties often occur (Bowden, 1963; Hargis, 1965;
Redfield, 1951). In horizontally and vertically
stratified mixing estuaries, there are two streams.
The upper stream, fresher and lighter, has a net-
flow downstream while the lower stream, saltier
• and heavier, flows inward or upstream. Since
these surface currents and bottom counter-cur-
rents often extend far to sea off the mouths of
large tidal tributary or estuarine systems, as well as
far upstream, significant upstream transport of ma-
terials in solution or suspension in the counter-
current can occur. These circulatory features are
important in the life cycles of many estuarine
species. For example, oyster and barnacle setting is
related to tidal and nontidal currents (Barlow,
1955; Bousfield, 1955; Emery and Stevenson,
1957; Hargis, 1966; Ketchum, 1954; Pritchard,
1953). Large disturbances of current patterns can
disrupt the life cycles of estuarine organisms.
Hence, projects that alter current patterns should
be carefully evaluated and controlled.
It is possible to alter circulatory patterns in tidal
tributaries by (1) changing the quantity, timing,
and location of fresh water inflow, (2) changing
the geometry of the basin. The former can be ac-
complished by construction and operation of reser-
voirs above or below the fall line (defined as the
uppermost limit of ocean's tidal activity). The
latter can be accomplished by shoreline or bottom
modification; e.g., drainage, bulkheading and fill-
ing, channel dredging, and subaqueous spoil dis-
posal or mining. Oyster harvesting practices have
been known to produce marked changes in bot-
tom geometry (Hargis, 1966).
Recommendation: In view of the requirements of
estuarine organisms and the nature of marine waters,
no changes in basin geometry or fresh water inflow
should be made in tidal tributaries which will alter
current patterns in such a way as to cause adverse
effects.
PH
Despite the great emphasis given to the impor-
tance of pH in the literature, little is known of its
direct physiological effects on marine organisms.
Its indirect effects, however, are extremely sig-
nificant. Even a slight change in pH indicates that
the buffering system inherent in sea water has been
altered radically and that either a potential or
actual carbon dioxide imbalance exists. This im-
balance can be deleterious or disastrous to marine
life. A second indirect effect is that pH can in-
fluence the toxicity of other materials. Cyanide and
ammonia, discussed under "Toxicity," are out-
standing examples of this kind of action.
Recommendation: Materials that extend normal ranges
of pH at any location by more than ±0.1 pH unit
should not be introduced into salt water portions of
tidal tributaries or coastal waters. At no time should
the introduction of foreign materials cause the pH to
be less than 6.7 or greater than 8.5.
Temperature
Temperature requirements of marine and estua-
rine organisms in the biota of a given region may
vary widely. Therefore, if we are to maintain tem-
perature favorable to the biota, all important spe-
cies, including the most sensitive, must be pro-
tected. It has been found that organisms in the
intertidal zone vary considerably in their ability
to withstand high temperatures. Those in the up-
permost areas of the tidal zone generally can with-
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stand higher temperatures than those in the lower
portions of the tidal zone and these in turn gen-
erally can withstand higher temperatures than the
same species of animals living in the subtidal
zones. In addition, when considering the coastline
as a whole, we must recognize that there are vari-
ous races within a given species which may vary
considerably in their environmental requirements,
or in their ability to withstand extreme conditions.
In our marine waters, there is a great mixture
of species. Species typical of higher latitudes are
found with species that are more abundant farther
south. Tropical or subtropical species generally
will spawn in the summer months. Species from the
higher latitudes require low water temperature for
spawning and the development of the young. Thus,
they usually spawn in the winter months and tem-
peratures at that time are critical. Any warming of
the water during the cold weather or winter pe-
riod could be disastrous from the standpoint of the
elimination of the more northerly species. In some
instances, a rise in winter temperatures of only 2
or 3 F might be sufficient to prevent spawning and
thus eliminate these species from the biota.
In the northern portions of the country there is
generally a great range in natural temperatures. In
southern areas, as we approach the tropics, we find
smaller overall temperature ranges. In the tropics
or subtropics, optimum temperatures for many
forms are only a few degrees lower than maximum
lethal temperatures. Great care should be exer-
cised, therefore, to prevent harmful increases in
maximum summer temperatures in tropical areas.
In general, temperatures in the marine waters
do not change as rapidly nor do they have the
overall range from extreme to extreme as they do
in fresh waters. Marine and estuarine fishes, there-
fore, are less tolerant of temperature variation.
They can accommodate somewhat, but overall
temperature range and rate of change are even
more important here than they are in fresh waters.
It has been observed that when surface water tem-
peratures over the Georges Bank increased from
46 to 68 F, the larval fish died at 65 F. It has been
found that species in subtropical and tropical en-
vironments are living at temperatures that are only
a few degrees less than their lethal temperatures.
In the most northern forms, extensive variations
in seasonal temperatures are a necessity for orderly
development and growth. Spawning and develop-
ment frequently occur at lower temperatures and
the sexual products ripen on rising temperatures
after a period of low temperatures. Temperatures
above or below the optimum range may delay or
speed up development. They may inhibit swim-
ming ability and the effectiveness of food utiliza-
tion may be decreased with increasing tempera-
tures in the upper viable range. Fishes and other
forms are also more susceptible to parasites and
diseases at temperatures outside of their optimum
range. In regard to rapid changes in temperature,
it has been found that a drop in temperature from
58 to 43 F kills sardines. Tolerable temperature
minima vary with the population and its past tem-
perature history. Kills have occurred off the Texas
coast at 40 F whereas kills of the same species
have occurred off Bermuda at a drop to 59 F.
Many kills have occurred in nature due to unusu-
ally low temperatures. Kills also occur due to
natural high temperatures. Yellowtail flounder and
whiting larvae died when they drifted from an area
of 44 F to one of 64 F. It has been reported that
61 F is best for the developing of mackerel, but
70 F is too high. These are merely illustrations of
what might happen to species occurring in inshore
waters.
It is apparent from the foregoing that data are
very sparse on temperature requirements of marine
and estuarine species. It is very difficult, therefore,
to attempt to suggest temperature requirements
for marine and estuarine forms. The difficulty is
compounded by the great extent of the Nation's
shorelines, the differing natural temperature varia-
tions from north to south, and the geographic over-
lapping of species native to different latitudes.
Consideration must be given to maximum allow-
able temperatures for both the summer period and
the winter period.
In attempting to establish permissible levels of
temperature increase in receiving waters due to
heated waste discharges, precaution must be taken
to prevent—
(a) excessive incremental increases above
background values even though such in-
cremental increases lie below maximum
limits, and
(b) exceeding maximum natural background
limits.
Such precautions are necessary to prevent grad-
ual net increases in background temperatures due
to the continuously increasing volumes of heated
wastes being discharged into receiving waters.
The discharge of heated wastes into estuaries
and other tidal tributaries must be managed so that
no barrier to the movement or migration of fish
and other aquatic life is created.
Recommendation: In view of the requirements for
the well-being and production of marine organisms, it
is concluded that the discharge of any heated waste
into any coastal or estuarine waters should be closely
managed. Monthly means of the maximum daily tem-
peratures recorded at the site in question and before
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the addition of any heat of artificial origin should not
be raised by more than 4 F during the fall, winter, and
spring (September through May), or by more than
1.5F during the summer (June through August).
North of Long Island and in the waters of the Pacific
Northwest (north of California), summer limits apply
July through September, and fall, winter, and spring
limits apply October through June. The rate of tem-
perature change should not exceed 1 F per hour except
when due to natural phenomena.
Suggested temperatures are to prevail outside of
established mixing zones as discussed in the section on
zones of passage.
coastal waters shall not be less than 5.0 mg/1, except
when natural phenomena cause this value to be de-
pressed.
(2) Dissolved oxygen concentrations in estuaries
and tidal tributaries shall not be less than 4.0 mg/1
at any time or place except in dystrophic waters or
where natural conditions cause this value to be de-
pressed.
The committee would like to stress the fact that, due
to a lack of fundamental information on the DO re-
quirements of marine and estuarine organisms, these
requirements are tentative and should be changed when
additional data indicate that they are inadequate.
Dissolved oxygen
Dissolved oxygen requirements of marine orga-
nisms are not as well known as those for freshwater
forms. Studies have been made indicating that
minimum dissolved oxygen concentrations of 0.75
to 2.5 are required for test species to resist death
for 24 hours. Most marine species died when the
dissolved oxygen dropped below 1.25 mg/1 for a
few hours. Reduced swimming speed and changes
in blood and serum constituents occurred at dis-
solved oxygen levels of 2.5 to 3 mg/1. It was
found that DO levels between 5.3 and 8 mg/1 were
satisfactory for survival and growth. Levels above
17 mg/I, however, produced adverse effects. Large
fluctuations in dissolved oxygen from 3 to 8 mg/1,
diurnal or otherwise, produced significantly more
physiological stress in fishes than fluctuations from
3 to 6 mg/1. In tests made to date, it has been
found that 5 to 8 mg/1 of DO is apparently suffi-
cient for all species of fish for good growth and
general well being. It is generally recognized that
in deeper waters DO values are often considerably
less than 5.0 mg/1. In estuaries where there is a
reduction in salinity, levels may drop to as low as
4 mg/1 at infrequent intervals and for limited pe-
riods of time. It is probable that many marine ani-
mals can live for long periods of time at much
lower levels of DO. Experimental studies with
freshwater organisms -have demonstrated, how-
ever, that low concentrations of DO at which adult
fishes can live almost indefinitely, can inhibit feed-
ing and growth. In determining DO requirements,
it is essential to consider growth, reproduction,
and other necessary life activities.
Recommendation: For the protection of marine re-
sources, it is essential that oxygen levels shall be suffi-
cient for survival, growth, reproduction, the general
well-being, and the production of a suitable crop. To
attain this objective, it is recommended that dissolved
oxygen concentrations in coastal waters, estuaries, and
tidal tributaries of the Nation, including Puerto Rico,
Alaska and Hawaii, should be as follows:
(1) Surface dissolved oxygen concentrations in
Crude oil and petroleum products
The discharge of crude oil and petroleum prod-
ucts into estuarine and coastal waters presents spe-
cial problems in water pollution abatement. Oils
from different sources have highly diverse proper-
ties and chemistry. Oils are relatively insoluble in
sea and brackish waters and surface action spreads
the oil in thin surface films of variable thickness,
depending on the amount of oil present. Oil, when
adsorbed on clay and other particles suspended in
the water, forms large, heavy aggregates that sink
to the bottom. Additional complications arise
from the formation of emulsions in water, leach-
ing of water soluble fractions, and coating and
tainting of sedentary animals, rocks, and tidal
flats.
Principal sources of oil pollution are numerous.
Listed in order of their destructiveness to ecosys-
tems, they are:
(1) Sudden and uncontrolled discharge from
wells towards the end of drilling operation.
(2) Escape from wrecked and submerged oil
tankers.
(3) Spillage of oil during loading and unload-
ing operations, leaky barges, and accidents
during transport.
(4) Discharge of oil-contaminated ballast and
bilge water into coastal areas and on the
high seas.
(5) Cleaning and flushing of oil tanks at sea.
On the average, a ship's content of such
wastes is estimated to contain 2 to 3 per-
cent oil in 1,000 to 2,000 tons of waste.
(6) Spillage from various shore installations,
refineries, railroads, city dumps, garages,
and various industrial plants.
Spillage From Wrecked Oil Tankers
Even though wrecks of oil tankers along the
Atlantic coast and subsequent spillage of oil into
the sea have been reported several times, no thor-
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ough examination has been made of the effect of
oil pollution on local marine life, except for fre-
quent references to the destruction of waterfowl.
One of these disasters attracted the general atten-
tion of the public and members of the Audubon
Society of New England. One night in 1952, two
tankers, the Fort Mercer and the Pendleton, went
aground on the shoal of Monomoy Point, Cape
Cod. Large amounts of oil spilled from the broken
vessels, spread long distances along the shore, and
were responsible for high mortality of ducks (scot-
ers and eiders). Many thousands of oil-smeared
dying birds were seen along the coast. Attempts to
save some of the birds by removing the oil with
various solvents failed. No published records are
found on the effect of this massive spillage on
aquatic life. According to the records of the Mas-
sachusetts Audubon Society, serious oil spreads
threatening fish and bird life have occurred at least
six times since 1923 along the beaches of Cape
Cod. The latest occurrence was on Sunday,
April 16, 1967. Heavy films of crude oil appeared
along the coast from Chatham to Provincetown,
Mass, and spread to Cape Cod Bay, Nantucket
Island, and Boston. The shores of the National
Seashore Park were seriously affected and hun-
dreds of ducks and brant were found dead or
dying.
The massive spillage of oil may constitute a
disaster of a national and even international mag-
nitude as has been dramatically demonstrated by
the wreck in March 1967 of the super tanker Tor-
rey Canyon carrying 118,000 tons of crude oil.
About one-half of the load gradually spilled near
Seven Stones Reef, off the southern coast of Eng-
land, where the tanker was stranded. By the middle
of April, patches of crude oil began to appear on
the French coast in Brittany, threatening the pro-
ductive oyster farms in the inlets and estuaries. It
is obvious that a disaster of such magnitude is be-
yond the scope of an ordinary pollution problem
in coastal waters. The probability of a recurrence
of heavy oil spillage is, however, very real because
of the present trend in the methods of transporting
oil in very large and apparently vulnerable tankers.
It has been reported that Japan operates a tanker,
Idemitsu Mam, of 205,000 tons holding capacity.
A super tanker of over 300,000 tons capacity is
under consideration and a design of a 500,000-
ton tanker appeared in the press.
Effect of Oil Spillage on Aquatic Life
of a Small Marine Cove
W. J. North, et al. (1965) made a valuable
study of the effect of massive spillage of crude oil
into a small cove in lower California Bay. Prior to
the spillage, the investigators were engaged in a
study of bottom fauna and flora of the cove and
were in possession of background information
which made it possible for them to record the
changes that took place after the water of the cove
was contaminated by the 59,000 barrels of oil that
escaped from the wreck of the tanker Tampico on
March 29, 1957. Among the many dead and dying
species observed a few weeks after the disaster, the
most frequently found were abalones (Haliotis
julgens, H. rufescens, and especially H. crachero-
dil), lobsters (Panulirus interruptus), pismo clams
(Tivela stultorum), mussels (Mytilus sp.), sea
urchins (Strongylocentrotus jranciscanus, S. pur-
puratus), and sea stars (Pisaster giganteus, P.
ochraceus). A slight improvement of the bottom
fauna was noticeable a few months after the dis-
aster, but extensive recovery became apparent only
2 years later. Four years after the accident, the
populations of abalones and sea urchins still were
reduced greatly and seven species of animals pre-
viously recorded in the cove had not been found
at all.
Combined Effect of Oil and Sewage Pollution
The oil and sewage pollution effects on aquatic
organisms of the Novorossiyak Bay (Black Sea,
U.S.S.R.) was recently studied by Kalugina, et al.
(1967). For a number of years, this bay has been
receiving a mixed daily discharge of 15,000 to
30,000 cubic meters of petroleum refinery wastes
and domestic sewage. There is marked decrease of
various valuable species of mollusks (Spisula
subtruncata, Tapes mgatus, Pecten ponticus) and
complete destruction of oyster beds (Ostrea
taurica) due to the combined effect of pollution
and depradations by a carnivorous gastropod
(Rapana). Samples were collected 1 to 25 meters
from the outfall for bioassay. Copepods (Acartia
clausi) placed in samples taken 25 meters from
the outfall were killed in 24 hours. Larvae of
decapods and gastropods in samples taken 10 to
25 meters out perished in 3 to 4 days. Calanus was
killed in 5 days in samples taken 1 meter out, but
survived the 10-day test in the samples taken 5,
10, and 25 meters from the outfall. There also was
a noticeable change in the distribution and species
composition of benthic algae.
Color of Oil Film on the Surface of Water
The color of the oil film on the water surface is
indicative of the thickness of the slick and may be
used as an indicator of the volume of oil spilled.
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According to data published by the American
Petroleum Institute (1949), the first trace of color
that may be observed as a surface film on the sea
is formed by 100 gallons of oil spread over 1
square mile. Films of much darker colors may
indicate 1,332 gallons of oil per square mile. Ex-
periments conducted by the Committee" on the
Prevention of Pollution of the Seas (1953) showed
that 15 tons of oil covered an area of 8 square
miles. In 8 days, it had drifted about 20 miles
from the point of discharge. The same committee
(1953) indicated another source of oil pollution
that should not be neglected. It has been found that
unburned fuel oil escaping through the funnels of
oil-burning ships may comprise 1 to 2 percent of
the total oil consumed and it may be deposited on
the sea surface. British investigators attributed the
disappearance of eel grass (Zostera) to minute
quantities of oil. Oil weakens the plant and makes
it susceptible to attacks of a parasitic protozoan
(Labyrinthula). Observations made several years
ago at Woods Hole showed that young Zostera
that began to reappear in local bays after several
years of absence were already infected by this
microorganism even though they appeared to be
healthy.
Adsorption of Oil by Sand, Clay, Silt, and
Other Suspended Particles
Oil of surface films is easily adsorbed on clay
particles and other suspended materials, forming
large and relatively heavy aggregates that sink to
the bottom. The surface of the water may appear
free from pollution, until the sediment is stirred by
wave action and the released oil floats up again.
During World War II, a product known as
"carbonized sand" was manufactured for the U.S.
Navy and used for the primary purpose of rapidly
removing oil spilled or leaked from ships. Carbon-
ized sand was used principally as a rapid method
to prevent and stop fires. Sand and oil aggregates,
being much heavier than sea water, sank very
rapidly and remained on the bottom. Experimental
work has shown that the toxic effect of oils is not
diminished by this method (Chipman and Galts-
off, 1949). Since the end of World War II, a num-
ber of preparations to be used as solvents, emulsi-
fiers, and dispersing agents of oil slicks in harbor
v/aters appeared in New Zealand, Western Europe,
and the United States. These preparations are be-
ing offered under various trade names and their
chemical composition is not always stated. It is
often claimed that such compounds remove oil
slicks more efficiently than mopping with straw or
coarse canvas fabric (skrim), a method exten-
sively used in Auckland Harbor (Chitty, 1948).
It is, however, generally recognized that various
detergents and emulsifiers are toxic to aquatic life
and therefore compound the danger of oil pollu-
tion. Mechanical means such as preventing the
spread of a slick by surrounding it with floating
barriers (plastic booms), spreading sawdust and
removing an oil aggregate by scooping or raking,
and erecting grass or straw barriers along the
beaches are probably more effective at present
than the chemical methods of dispersing or dis-
solving oil. Even anchoring oil by combining it
with relatively heavy carbonized sand seems to be
preferable to chemical methods.
Toxicity of Crude Oil and Petroleum Products
Oil may injure aquatic life by direct contact
with the organism, by poisoning with various water
soluble substances that may be leached from oil,
or by emulsions of oil which may smear the gills or
be swallowed with water and food. A heavy oil
film on the water surface may interfere with the
exchange of gases and respiration.
A number of observations have been recorded
of the concentrations of oil in sea water which are
deleterious to various species. Experimental data,
however, are scarce and consequently the toxicol-
ogy of oil to marine organisms is not well under-
stood.
Nelson (1925) observed marine mollusks (Mya
arenaria) being destroyed by oil on tidal flats of
Staten Island, N.Y. The Pacific coast sea urchin,
Strongylocentrotus purpuratus, dies in about 1
hour in a 0.1 percent emulsion of diesel oil. After
20 to 40 minutes in this concentration the animals
fail to cling to the bottom and may be washed
away (North, et al., 1964).
Crude oil absorbed by carbonized sand does not
lose its toxicity. This has been shown by laboratory
experiments conducted at Woods Hole (Chipman
and Galtsoff, 1949). The amount of oil used was
limited to the quantity held in the sand, hence no
free oil was present in the water. The oil-sand
aggregates were placed in containers filled with sea
water but never came into contact with the test
animals. Four species were bioassayed: the very
hardy toadfish (Opsanus tau) in the yolk sac
stage, the moderately tolerant barnacle (Balanus
balanoides), and oyster (Crassostrea virginica),
and the extremely sensitive hydrozoan, (Tubularia
crocea).
The survival of toadfish embryos was indirectly
proportional to the concentration of oil in water.
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In a concentration of 0.5 percent, the embryos sur-
vived for 13 days (end of test); in 1.25 percent,
8i days; in 2.5 percent, 6 days; and in 5 percent,
4J days. Barnacles suffered 80 to 90-percent
mortality within 70 hours in 2.0-percent mixtures
of oil in sea water. They became inactive in 23
hours in concentrations of 2 percent and above.
Tubularia suffered 90 to 100-percent mortality
within 24 hours after being placed in water con-
taining a 1:200 oil-carbonized sand aggregate.
Water extracts of crude oil were lethal within 24
hours at concentrations of 500 mg/1 and greater.
Experiments with oysters consisted primarily of
determining the effect of oil adsorbed on carbon-
ized sand on the number of hours the oysters re-
main open and feeding and on the rate of water
transport, across the gills. A paste-like aggregate of
oil in carbonized sand (50 ml crude oil to 127 g
sand) was prepared, wiped clean of excess oil, and
placed in the mixing chamber. Sea water was de-
livered through this chamber to the recording ap-
paratus at a rate slightly in excess of the rate of
water transport by oyster gills (Galtsoff, 1964;
Chipman and Galtsoff, 1949). There was a notice-
able decrease in the number of hours the test
oysters remained open and in the daily water trans-
port rate through the gills. The time open was re-
duced from 95 to 100 percent during the first 4
days of testing to only 19-8 percent on the 14th
day. The total amount of water transported per
day, and presumably used for feeding and respira-
tion, was reduced from 207 to 310 liters during the
first 6 days to only 2.9 to 1 liter per day during
the period between the eighth and 14th day of
continuous testing. These tests indicate that oil
incorporated into the sediments near oyster beds
continues to leach water-soluble substances which
depress the normal functions of the mollusk.
Critical observations are lacking on the effect of
oil on pelagic larvae of marine invertebrates, but
there is good reason to assume that crude oil and
petroleum products are highly toxic to free-swim-
ming larvae of oysters. Speer (1928) considers
that they are killed by contact with surface oil film.
Laboratory experience of Galtsoff (unpublished
records) shows that oyster larvae from 5 to 6 days
old were killed when minor quantities of fuel oil
were spilled by ships in the Woods Hole harbor
and the contaminated water penetrated into the
laboratory sea water supply.
The tests described above leave no doubt that
water-soluble substances are leached from oil
spilled into water and adversely affect marine life.
It is reasonable to assume that the water soluble
materials of oil may contain various hydrocarbons,
phenols, sulfides, and other substances toxic to
aquatic life. The water-soluble fraction leached
from crude oil is easily oxidized by aeration and
loses its toxicity (Chipman and Galtsoff, 1949).
Carcinogenic Substances From
Oil-Polluted Waters
Presence of hydrocarbons similar to benzo-
pyrene in oil-polluted coastal waters and sediments
of France in the Mediterranean was reported by
Mallet (1965) and Mallet and Sardou (1965).
The effluents from the industrial establishments on
the shores at Villefranche Bay comprise tar sub-
stances, which contain benzopyrenes, benzo-8,
9-fluoranthene, dibenzanthracenes, chrysene, 10-
methyl anthracene, and nitrogenous derivatives
such as dimethylbenzacridine. These substances
are carried out into the bay water and settle on the
bottom. The pollution is augmented by incom-
pletely burned oils discharged by turbine ships.
The content of benzopyrene in bottom sediments
ranges from 500 micrograms in 100 g sample col-
lected at the depth of 8 to 13 cm to 1.6 micro-
grams at 200 cm. Similar contamination is of im-
portance in the Gulf of Fos, Etang de Berne, and
in the delta of the Rhone River.
Carcinogenic hydrocarbons were found to be
stored in plankton of the bay of Villefranche, in
concentrations varying from 2.5 to 40 micrograms
per 100 g. Fixation of benzopyrenes was found
also in the bodies of holothurians (Lalou, 1965)
in a bay near Antibes. The reported concentration
in the visceral mass of holothurian was slightly
higher than that in the bottom sediment.
Observations on storage of carcinogenic com-
pounds found in oil-polluted water are biologically
significant. The important question of biological
magnification as these compounds are ingested by
plankton feeders remains unanswered and needs
to be investigated.
Sampling of Oil-Polluted Sea Water
The question of the minimal concentration of oil
and petroleum products consistent with unin-
hibited growth and reproduction of aquatic species
is more difficult to answer than it is in the case of
other contaminants. As has been shown above, oil
is found in water in four distinct phases: (1) sur-
face oil film, (2) emulsion in sea water, (3) ex-
tract of water soluble substances, and (4) semi-
solid aggregate of oil and sediment covering the
bottom. Obviously, no single sample could include
all four phases and the method of sampling should
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vary accordingly. Collection of samples of a heavy
oil slick near the origin of spillage presents no par-
ticular difficulty because an adequate quantity may
be scooped easily and placed in a proper container.
Serious difficulty arises, however, in case of an
irridescent film of oil approaching the thickness of
a monomolecular layer. Garrett (1964), made a
special study of slick-forming materials naturally
occurring on sea surfaces and demonstrated their
highly complex composition. The collection of
very thin layers of surface water was made by
means of a specially constructed plastic screen.
The entrapped compounds were washed off into
a large container (Garrett, 1962). He found sur-
face-acting substances in all areas where the sea
surface was altered by monomolecular films and
concluded that "a chemical potential exists
whereby such surface alterations can occur when
conditions are suitable for the adsorption and
compression of the surface-active molecules at
the air/water boundary." The oil film at the
air/water boundary may be composed of several
interacting organic compounds. This complexity
must be kept in mind in studies of oil pollution in
sea water.
If a relatively thick layer of contaminated water
is needed, the sample may be scooped or sucked
from an area of sea surface enclosed by a floating
frame. Interference due to wave ripples is mini-
mized in this way.
For analysis of an oil emulsion in sea water, a
sample of a desired volume may be collected by
pump or by any type of self-closing water bottle
lowered within the surf area.
For obtaining water soluble substances leached
from oil sludge, sampling should be made by
pumping or by using a water sampler lowered as
close as possible to the oil-covered bottom.
Samples of oil adsorbed on sediments can be
obtained by using bottom samplers designed to
take quantitative samples.
Contamination of beaches by floating tar ballast
and cleaning water discharged by ships sailing
along our coast is of such common occurrence that
at present it is almost impossible to find a public
beach free from this nuisance. Cakes of solidified
oil tar can be picked by hand from the tidal zone
of any beach along the Atlantic and Gulf coasts.
Recommendation: Until more information on the
chemistry and toxicology of oil in sea water becomes
available, the following requirements are recommended
for the protection of marine life. No oil or petroleum
products should be discharged into estuarine or coastal
waters in quantities that (1) can be detected as a
visible film or sheen, or by odor, (2) cause tainting
of fish and/or edible invertebrates, (3) form an oil-
sludge deposit on the shores or bottom of the receiving
body of water, or (4) become effective toxicants ac-
cording to the criteria recommended in the "Toxicity"
section.
Turbidity and color
Turbidity, color, and transparency are closely
interrelated phenomena in water. They must be
observed simultaneously because transparency is
a function of turbidity, water color, and spectral
quality of transmitted light. For practical pur-
poses, however, it is more convenient to discuss
them separately.
Turbidity
By observing the turbidity of sea water it is pos-
sible to determine the depth of the euphotic zone;
i.e., the depth in which organic carbon is produced.
Various particles suspended in water reduce the
intensity of light by absorption and scattering. In
the sea, the maximum depth of growth of attached
plants varies. It is 160 m in the Mediterranean,
30 m in Puget Sound, and 10m off Cape Cod. In
general, benthic plants will not grow at a depth at
which the light intensity is less than 0.3 percent of
its surface value (Clarke, 1954). In any environ-
ment, the rate of photosynthesis decreases with the
attenuation of light but the respiration rate remains
approximately the same. Because the role of
phytoplankton in organic production is far more
important quantitatively than that of benthic
plants, an increase in the turbidity of water di-
minishes primary productivity of the ocean bio-
mass as indicated by the rate of growth of various
planktonic algae.
For each species of plant, a level of light inten-
sity may be reached at which the rate of photo-
synthesis becomes equal to the rate of respiration.
This level is designated as compensation intensity
and the depth at which this value is found is called
the compensation depth. For marine phytoplank-
ton, it has been determined that compensation in-
tensity is about 100 ft-candles, or 1 percent of the
value of full sunlight (Clarke, 1954). In natural
waters, the compensation depth varies; e.g., in the
Gulf of Maine it was found to be 30 m while at
Woods Hole only 7 m.
In many coastal waters, the principal cause of
turbidity is the discharge of silt carried out by the
principal rivers. Secchi disc readings show that the
transparency of water at the mouths of large rivers
during flood stage may be reduced to a few centi-
meters. At normal river stages, the disc may be
visible at several meters below the surface. Ob-
servations from an airplane are useful in recording
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the distribution of brackish, silt-laden waters along
the coast. Silting of the estuaries and adjacent
coastal water should be considered as a special
case of pollution resulting from deforestation,
overgrazing and faulty agricultural practices, road
construction, and other land management abuses.
Mixed effluents from various industrial plants
and domestic sewage increase the turbidity of
receiving water. It is difficult to distinguish be-
tween the effect of the attenuation of light due to
suspended particles and the direct effect of the
particles in suspension on the growth and physi-
ology of aquatic organisms. Natural silt taken
from the bottom of the sea and kaolin affect the
development of eggs and the growth of larvae of
oysters and hard shell clams (Mercenaria merce-
naria). In a suspension of 2 g of dry silt in a liter
of sea water, only 39 percent of oyster larvae com-
pleted development. In 3 g per liter there was no
development (Loosanoff, 1962). Growth of
Mercenaria clams was retarded in the concentra-
tion of 1 to 2 g/1, but appeared to be normal at
0.75 g/1. Development was completely suppressed
in the concentration of silt from 3 to 4 g/1 (Davis,
1960). Silt concentration of 0.1 g/1 caused a 57-
percent decrease in the water transport of an adult
oyster. In 4 g/1, the depression was 94 percent
(Loosanoff, 1962). The turbidity used in these
experiments probably is equivalent to 750 to
4,000 mg/1 of turbidity standards, although direct
comparison of figures cannot be made accurately.
The principal significance of turbidity observa-
tions in a study of pollution is the determination of
the depth of the euphotic zone as a factor affecting
primary productivity of the sea (Ryther, 1963).
Determination of the coefficient "k" defined as the
natural logarithm of the fraction of incident light
penetrating to a given depth is of great importance
in studies of organic production. In the temperate
and northern parts of the ocean, values of "k"
range between 0.10 to 0.20 and correspond to
depths of 50 to 25 m. In more turbid coastal
waters, the coefficient of extinction is as high as
1.0 and a compensation depth of 5 m is com-
monly encountered. These values may be used as
a basis for comparing the characteristics of uncon-
taminated waters with those of highly turbid and
polluted waters of coastal and inshore areas. A
considerable part of the turbidity of these areas is
attributable to nonliving particles.
It must remembered, also, that very high tur-
bidity of sea water may be due entirely to blooms
such as are known to occur in red tide areas
(Galtsoff, 1949) or as a result of unbalanced over-
fertilization such as is induced by organic wastes
from duck farms in Great South Bay, N.Y. Tur-
bidity may be determined practically by use of a
Secchi disc. Turbidity may be determined more
accurately by using the techniques described in
Standard Methods for the Examination of Water
and Wastewater, 12th edition (1965). Any tur-
bidity of less than 1 m (by Secchi disc) or in cor-
responding Jackson units should be regarded with
suspicion and the nature of suspended material as
well as the composition of plankton determined.
Color
The color of sea water, expressed as dominant
wave length in millimicrons (m/x) covers the
range from violet (400 to 465 m,u) to red-purple
(530 to 700 m^,). Spectrophotometric methods, as
described in Standard Methods for the Examina-
tion of Water and Wastewater, 12th edition
(1965), should be used if careful study is re-
quired, particularly for determining the exact color
of water contaminated with industrial wastes.
Monitoring the color changes of sea water yields
information on the extent of intrusion of fresh
water into the sea, the intensity and extent of silt-
ing, the location and extent of plankton blooms,
the extent and distribution of pollution from indus-
trial waste effluents, and the presence and probable
thickness of oil film.
In brackish waters, the blue hue of the open sea
is replaced by a greenish or yellowish color. Silting
areas are recognizable by brown or yellowish dis-
coloration. Red-brownish color is typical of the
red tide caused by Gymnodinium and other spe-
cies of dinoflagellates. Some of these are toxic to
fishes and benthic invertebrates (Galtsoff, 1948,
1949). Mass production of forms such as the blue-
green alga Trichodesmlum gives the surface of the
sea an appearance of "green meadow" as described
for the Azov Sea by Knipowich (Galtsoff, 1949).
Swarming of Phaeocystis poucheti, P. globosa, and
Rhizosolenia have been reported to extend over
hundreds of square miles of the open sea causing
a distinct brownish discoloration.
Systematic studies have not been made yet to
determine the optical characteristics of discolored
sea water. It is reasonable to expect that such an
investigation would be valuable in explaining the
cause of discoloration and, in certain instances,
may indicate the presence and nature of pollution.
Light components specific for the contaminant
entering sea water may be detected by the use of
a spectrophotometer or with the recording SPOT
spectroradiometer recently developed by Alfred C.
Konrad of the Massachusetts Institute of Tech-
nology. This type of instrument is being used at
present at the Woods Hole Oceanographic Institu-
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tion and is proving very useful. Spectroradiometer
observations can be made either from an airplane
or from shipboard.
Recommendation: No effluent which may cause
changes in turbidity or color should be added to, or
discharged into, inshore or coastal waters unless it has
been shown that it will not be deleterious to aquatic
biota.
Settleable and floating substances
Settleable solids entering coastal waters include
various products of forest industries such as saw-
dust, bark chips, wood fibers, sewage solids,
and many industrial wastes. The old practice of
dumping sawdust into tidal rivers was discon-
tinued long ago, but its effect is still visible in
the rivers of Maine. For instance, an area of the
bottom of the Damariscotta River was still cov-
ered with a loose layer of sawdust about 2 to 3 feet
deep in 1940, although operation of the lumber
mills responsible for this deposition had ceased
more than 50 years previous. The Damariscotta
kitchen-midden on the banks of the river contains
a huge accumulation of river oyster shells and
some artifacts left here by the Indians who lived
there for several centuries of pre-Colonial times.
The habitat was so completely changed by pollu-
tion that at present there is hardly any benthic
organism found on this formerly productive bot-
tom (Galtsoff and Chipman, unpublished report).
Decay-resisting organic matter from wood fibers
and waterlogged bark and chips constitutes, in
places, a serious handicap to aquatic life. Settle-
able materials from mining operations and gravel
and sand washing make the bottom unsuitable for
aquatic life in the affected areas of the receiving
bodies of water. Silting may be so heavy that the
sediment brought in may completely fill the bay.
One can see this in the eastern branch of Mata-
gorda Bay, Tex., an area that has been completely
obliterated within the last 25 years by the Colo-
rado River.
Dredging of bays and tidal rivers for improve-
ment of navigation occasionally presents serious
problems. Benthic communities in the area near
dredging operations may be destroyed or damaged
by spoil deposition, increase in water turbidity,
release of toxic substances accumulated in the mud
of the polluted areas, and by changing the pattern
of currents in the dredged area.
Careful studies of the effects of dredging on
oyster-producing bottoms of the Santee River,
S.C., were made in 1936 by G. Robert Lunz, Jr.
(unpublished report), for the U.S. Corps of Engi-
neers. No deleterious effect on oyster-producing
bottoms was found. An examination made by the
Bureau of Fisheries Laboratory at Woods Hole of
dredging operations to deepen and enlarge the
Cape Cod Canal disclosed that several productive
oyster beds near the site of dredging were covered
by 2 to 3 feet of sand and silt. The oysters were
destroyed, but the grounds soon were re-populated
by hard-shell clams and the productivity of the
area restored.
Disposal of the huge quantities of garbage ac-
cumulated by large cities presents a special and
difficult problem. The old practice of barging this
waste out to sea and dumping it is highly objection-
able. Incineration seems to be the answer. This
creates, however, the problem of proper incinera-
tion of large quantities of materials without in-
creasing air pollution over the metropolis. The city
of Boston disposes of large amounts of accumu-
lated garbage and trash by incineration and by
dumping the ashes into the sea at a distance from
shore. State and Federal authorities are engaged
presently in a study of the chemical composition
of ash and its possible effect on aquatic life in the
sea. Preliminary analysis of an incinerated sample
made by Ronald Eisler (personal communication)
of the National Marine Quality Laboratory of the
Federal Water Pollution Control Administration
shows that aluminum, iron, and calcium were most
abundant, followed by zinc, sodium, potassium,
and lead. Other metals comprising more than 1
percent of the fraction soluble in 6NHC1 include
barium, chromium, and magnesium. It is evident
that ash from this waste contains a fairly large
percentage of heavy metals which may be accumu-
lating in the bodies of fish and shellfish. The effect
of ash on the behavior of fish is now being studied,
but the results are not yet available.
Examples of industrial effluents containing ma-
terials that precipitate in sea water are the waste
from titanium paint plants or the soap portion of
the effluents from Kraft pulp mills. This fraction of
the black liquor is precipitated from solution by
salt, carried by the current of the receiving river,
and eventually deposited on the bottom (Galtsoff,
et al., 1947). Waste from several plants extracting
titanium dioxide from ilemenite (ferrous titanate)
produces serious pollution in the lower Patapsco
River area near Baltimore. Because of the re-
stricted circulation of water in the upper Chesa-
peake Bay, the effect is quite pronounced. Ferric
hydroxide flocculation in the Patapsco River has
been found detrimental to plankton. Diatoms were
destroyed by flocculation and removed from
plankton by settling with the iron particles. Con-
siderable amounts of iron accumulated on the
bottom and iron precipitate was found coating the
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gills of minnows, silverside, and white perch
(Olson, et al, 1941).
Recommendation: Water quality requirements for
specifying the permissible limits of settleable solids and
floating materials cannot be expressed quantitatively at
present. Since it is known that even minor deposits may
reduce productivity and alter the benthic environment,
it is recommended that no materials containing settle-
able solids or substances that may precipitate out in
quantities that adversely affect the biota should be in-
troduced into estuarine or coastal waters. It is espe-
cially urgent that areas serving as habitat or nursery
grounds for commercially important species (scallops,
lobsters, oysters, clams, crabs, shrimp, halibut, floun-
ders, demersal fish eggs and larvae, and other bottom
forms) be protected from any infringement on natural
conditions.
Tainting Substances
Substances found in industrial wastes are fre-
quently responsible for objectionable or offensive
tastes, odors, and colors of fish and shellfish. Even
slight amounts of oil or petroleum products in
bays and estuaries will impart an oil or kerosene
flavor to mullet, mackerel, and other fishes and
also to oysters, clams, and mussels making them
unmarketable. Oysters collected in Louisiana
waters polluted by crude oil retained a distinct
flavor and odor associated with this type of pollu-
tion for several weeks after the escape of crude oil
from wells and leaky barges had been stopped
(Galtsoff, et al., 1935).
Anaerobic conditions associated with the de-
posit of sewage sludge on the bottom are accom-
panied by the production of hydrogen sulfide, a
substance that causes black discoloration of bi-
valve shells and imparts an offensive flavor and
odor to their flesh. In the waters receiving black
liquor from Kraft pulp mills in the York River,
Va., the gills and mantles of oysters developed a
gray color. This condition also is found in oysters
grown in waters receiving domestic sewage (Galt-
soff, etal., 1957).
Contamination of water with copper results in
the accumulation and storage of this metal far
above its normal content in the tissues. The cop-
per content of oyster flesh from uncontaminated
waters off Cape Cod varied from 0.170 to 0.214
mg copper per oyster or from 8.21 to 13.77 mg
per 100 g dry weight. In green colored oysters
collected from adjacent areas only slightly con-
taminated with copper salts, the copper content in
the flesh ranged from 1.27 to 2.46 mg per oyster
or from 121.71 to 271 mg per 100 g dry weight
(Galtsoff and Whipple, 1931; Galtsoff, 1964).
In a current study conducted at the Northeast
Marine Health Sciences Laboratory, at Narragan-
sett, R.I., Dr. B. H. Pringle (unpublished data)
found that the average copper content of oysters
collected from unpolluted areas along the east
shore ranged from 20 to 80 mg/1, wet weight;
oysters from areas known to be polluted contained
from 124.5 to 392.0 mg/1 wet weight. The copper
content of sea water ranged between 0.0038 to
0.005 mg/1 in areas not known to be polluted. In
certain polluted places, concentrations as high as
0.019 mg/1 were recorded.
Other metals are easily absorbed, stored, and
concentrated by oysters in great excess of their
concentration in sea water. Experimentally, it has
been shown that iron and iodine can be absorbed
within a relatively short time by oysters from water
to which these metals have been added in excess.
The flavor of so-called superiodized oysters pro-
duced before World War II in Arcachon, France,
was pronounced because the iodine content of flesh
was many times higher than that in untreated
oysters (Galtsoff, 1964). The color of the oysters
was not affected.
Green color of the gills of the European oyster
in France and in the American oyster occasionally
found in North Carolina and Chesapeake Bay is
due to absorption of the blue-green pigment of the
diatom, Navicula, present in large numbers on
oyster grounds. The color is not associated with
the increased copper content of flesh (Ranson,
1927).
Recommendation: To prevent the tainting of fish and
other marine organisms, substances that produce tastes
and off-flavors should not be present in concentrations
above those shown to be acceptable by means of bio-
assays and taste panels. Experience has shown that test
organisms should be exposed to the materials under
test for 2 weeks at selected concentrations to determine
the maximum concentration that does not produce
noticeable off-flavors as determined by organoleptic
tests. (Cooking should be done by baking the material
wrapped in aluminum foil.)
Plant Nutrients and Nuisance Organisms
Plant nutrients and nuisance organisms are in-
terrelated in many ways. There also are many
other factors in the environment, such as tempera-
ture and salinity, that are closely correlated and,
in many instances, seem to be contributing factors
to nuisance organisms.
Man, through altering the hydrography of his
environment by building dams and diverting
waterflows from their natural courses, has pro-
duced conditions in many areas that have caused
nuisance growths and brought about an imbalance
of natural conditions. He also has enriched surface
waters and created imbalances in dissolved mate-
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rials and organisms through careless land man-
agement and by allowing the introduction of
nutrients from sewers, food processing industries,
fertilizer plants, feed lots, and farms. As a result,
natural communities of aquatic life are altered
and the functioning of these ecosystems often
is changed severely or destroyed.
To maintain natural distribution, abundance,
and interrelations of the aquatic biota, and to
control unwanted growths, it is necessary to de-
termine and maintain levels of dissolved materi-
als required for this balance. This is an extremely
difficult task, however, because there are a great
many interrelated factors that contribute to the
development of excessive populations of a species.
Although a considerable amount of work has been
done on the nutrition of aquatic organisms, most
of this work has been done on a very few different
species. Very little research has been done to deter-
mine what interaction of factors causes a shift in
diversity or in the kinds of species that compose a
community. For these reasons it is impossible to
set any definite requirements. At this time the only
meaningful thing that can be done is to develop
guidelines.
Plant Nutrients: The increase of nutrients in the
sea is accelerated by deposition of material derived
from the land as sediments from the rivers, by
settling and filling caused by water movements
produced by tide or wind, and by biological activ-
ity. To date, no serious problems resulting from
abnormal enrichment of nutrients have been iden-
tified in the open sea except perhaps locally around
outfalls that extend several miles out to sea. With
the increased disposal of wastes in the sea, this
potential problem should be carefully watched.
Estuaries and tidal embayments have long been
recognized as some of our most valuable and pro-
ductive resources. They are the most ephemeral of
the natural marine habitats and consequently most
easily affected by man's activities. They serve as
sinks for most of the organic and inorganic mate-
rials resulting from land erosion. Because of the
lack of scouring and the nature of the sediments
that occur in some areas, anaerobic conditions
often develop in the beds of estuaries and bays.
Increases in the deposition of suspended solids
intensifies this condition. An excellent discussion
of the role of sediments in an estuary is given by
Carriker(1967).
Many industries and municipalities discharge
nutrient-rich wastes into estuaries. Because of the
nature of the estuary, these are recycled and ac-
cumulated over a period of time. Because of this
recycling, effluents with low concentrations of nu-
trients may, in time, produce serious problems.
The complete flushing of the estuary often takes
many years. With controlled water discharges, this
problem may become more severe.
Plant nutrients consist of many types of chemi-
cals. For example, we have the chemicals com-
monly recognized as being important in plant
nutrition such as nitrate, phosphate, sulfate, car-
bonate, calcium, magnesium, sodium, and potas-
sium. There are also the so-called "trace elements"
which are equally important but are required in
small amounts such as iron, manganese, molybde-
num, cobalt, zinc, etc. More recently the impor-
tance of organic compounds in plant nutrition has
been recognized. These include vitamins, such as
vitamin B12, organic forms of nitrogen, such as
urea, various amino acids, and amides, and the
simple sugars, such as glucose.
The role of dissolved organic compounds in the
nutrition of plants as well as animals appears to be
important. Darnell (1967) refers to the aquatic
medium as a "vegetable soup" to indicate its rich-
ness in dissolved organic materials. The work of
Ryther (1954) points out that the organic forms
of nitrogen are best utilized by the less desirable
species (Nannachloris atomus and Stichoccus sp.).
Nitzschia, a desirable diatom, often grows poorly
in their presence. This is no doubt a major reason
why sewage effluents often bring about the devel-
opment of undesirable species.
If the increased nutrients in a system are well
balanced, many species will have larger popula-
tions, the predator pressure will increase, and the
productivity of the whole ecosystem will increase.
If, however, the increased nutrients are of undesir-
able composition for most forms of aquatic life, or
not in the correct ratio, excessive blooms of spe-
cies with low predator pressures may develop.
Examples of these are certain blue-green algae. Of
course, environmental factors other than nutrients
are important in the development of blooms. Any
one important factor, such as temperature, light,
or water mass stability, if limiting, may prevent
blooms even though other conditions are suitable
for their development. As a result, blooms some-
times do not develop even though most of the
conditions are favorable.
Nuisance Organisms: Nuisance organisms in
the marine environment are usually defined as
those organisms which interfere with the use that
man wishes to make of a particular water. Some
examples are abnormally abundant growths of or-
ganisms that make bathing beaches unattractive,
produce unpleasant odors, foul the bottoms of
boats, spoil the esthetic appearance of water and
the coastline, clog fishing nets, interfere with the
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flow of water within intake and effluent pipes, and
interfere with navigation. This category of nuisance
organisms should also include those organisms that
interfere with the growth and reproduction of or-
ganisms important to man. For example, excessive
populations of boring sponge or oyster drills,
rooted and floating aquatics can interfere with the
movement and reproduction of fish; bacteria and
red tide organisms such as Gymnodinium and
Gonyaulax may have toxic effects on other orga-
nisms, including man (Rounsefell and Nelson,
1966;Felsing, 1966).
The groups of organisms that may cause nui-
sances or become severe pests include algae (in-
cluding red tide organisms), coelenterates,
sponges, mollusks, such as oyster drills and mus-
sels, and Crustacea. These organisms are com-
monly encountered in the natural marine environ-
ment. Organisms may become nuisances because
of excessive growth and changes in distribution
patterns and predator-prey relationships. The main
causative factors are excessive and, often, imba-
lanced nutrients, considerable changes in the na-
tural regimes of temperature, turbidity, and salin-
ity, and changes in current patterns.
In some instances, nuisance growths seem to be
directly related to the nutrients that are available.
In other situations, nuisance growths may not be
directly affected by artificial enrichment, so far as
we know, and seem to be more strongly affected
by changes in the temperature, salinity, or turbid-
ity. Included here are various fouling organisms:
barnacles, mussels and other mollusks, polyzoa
tube worms, marine borers, and pests to useful
marine products (oyster drills, boring sponges,
crabs, parasitic fungi, and protozoans), and
swarms of jellyfish, which make bathing in some
coastal waters hazardous during certain seasons.
The effect of increased nutrients may be an in-
crease in the populations of certain species already
present in the environment and a decrease of spe-
cies that are not tolerant of such nutrients. Exam-
ples of such conditions are the increase of Entero-
morpha and sea lettuce, Ulva lactuca, in the zone
of mineralization of sewage which occurs in some
areas of the lower Potomac. In areas of higher
salinity, abundant growths of Ascophyllum often
occur in waters containing mineralized effluents
from sewage treatment plants. In Biscayne Bay,
Fla., the following organisms became abundant
under such conditions: the flowering plants, Halo-
phila baillonis and Diplanthera wrightii; and the
echinoderm, Amphioplus abditus. Under heavy
organic enrichment, the algae, Gracilaria blodgettii
and Agardhiella tenera, the worm, Diopatra cu-
pera, and the amphipods, Erichthonius brasiliensis
and Corophium acherusicum, became very com-
mon (McNulty, 1955).
In other cases, an imbalanced organic enrich-
ment together with changes in temperature and
salinity brings about an almost complete change in
the species composing an aquatic community plus
excessive growths of some species. An excellent
example of this type has been described by Ryther
(1954) in his studies of Moriches Bay and Great
South Bay, Long Island. In this area, duck farm
wastes enrich the bay waters with organic com-
pounds that produce a low nitrogen-to-phosphorus
ratio. At the times of the largest algal blooms, low
salinities and high temperatures exist in the area.
As a result, desirable marine diatom species of
Nitzschia which prefer cool water (5 to 25 C), ni-
trates, and nitrites as a source of nitrogen, and are
not benefited by a low N/P ratio (5:1) were re-
placed by Nannochloris atomus and Stichococcus
sp. These species can grow well in nitrates, nitrites,
ammonia, urea, uric acid, and cystine, and prefer
a N/P ratio of 5:1. As Ketchum (1967) points
out, these weed species are undesirable food
sources and the natural productivity of the estuary
is destroyed. Ketchum also points out that the
greatest amount of plankton does not always oc-
cur in the waters of greatest enrichment. This is
because the development of a maximum standing
crop of phytoplankton is also governed by the con-
centration of predators, stability of the water
column, transparency of the water, etc.
Nutrient imbalance may affect the ratio of inor-
ganic phosphate to total phosphorus, here defined
as the sum of inorganic, organic, and paniculate
phosphorus. It is known from the work of Pomeroy
(1960) and others that inorganic phosphorus is
rapidly taken up by actively growing plants. At the
same time, inorganic phosphorus is regenerated as
a result of bacterial degradation and excretion by
animals. The net effect over the short run is to pro-
duce a steady state between the various fractions
of phosphorus in the environment. There should
be some ratio of inorganic to total phosphorus in
the euphotic zone that would be characteristic of a
balanced nutrient regime and this ratio should be
lower than the same ratio for the imbalanced
system in which inorganic phosphorus can
accumulate.
Data from Moriches Bay and Great South Bay
on Long Island, Charlestown Pond, R.I., the North
Atlantic, and the North Pacific have been ex-
amined. In the obviously polluted portion of Mori-
ches Bay, the inorganic total phosphate ratio gen-
erally exceeds 0.6, while the Charlestown Pond, an
uncontaminated estuary of similar characteristics
to Moriches Bay, this ratio was less than 0.4. In
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the open ocean at high latitudes and in the winter
when phytoplankton density is low, the fraction of
inorganic phosphorus may increase to 0.65 or
thereabout.
Recommendation: The ecological factors most often
associated with nuisance growths are changes in the
natural temperature and salinity cycles and increases
in nutrients. The change in any of these factors may
directly or indirectly affect the response of the orga-
nisms to other factors. Increase or decrease in current
and, indirectly, its effect on available nutritional ma-
terials have also been found to be important.
To maintain a balance among nutrients and a bal-
anced biota most conducive to the production of a
desired crop, it is recommended that:
(1) No changes should be made in the basin geom-
etry, current structure, salinity, or temperature of the
estuary without first studying the effects on aquatic life.
For example, these studies should be made before dams
are erected, water diversion projects are constructed,
or dredge and fill operations carried out.
(2) The artificial enrichment of the marine en-
vironment from all sources should not cause any major
quantitative or qualitative alteration in the flora. Pro-
duction of persistant blooms of phytoplankton, whether
toxic or not, dense growths of attached algae or higher
aquatics or any other sort of nuisance that can be
directly attributed to nutrient excess or imbalance
should be avoided. Because these nutrients often are
derived largely from drainage from land, special atten-
tion should be given to correct land management in a
river basin and on the shores of a bay to prevent ero-
sion.
(3) The naturally occurring atomic ratio of NO>-N
to PO,-P in a body of water should be maintained.
Similarly, the ratio of inorganic phosphorus (ortho-
phosphate) to total phosphorus (the sum of inorganic
phosphorus, dissolved organic phosphorus, and par-
ticulate phosphorus) should be maintained as it occurs
naturally. Imbalances have been shown to bring about
a change in the natural diversity of the desirable orga-
nisms and to reduce productivity.
Toxic Substances
Relatively few of the many substances recog-
nized as potential toxic pollutants of the marine
environment have been studied sufficiently to en-
able us to define their maximum allowable concen-
trations. Specific pollutants and classes of pollu-
tants are discussed in terms of current knowledge.
In some cases, data are adequate to set definite
criteria, while in others, criteria are educated
guesses at best and can serve only as temporary
guidelines.
Lethal concentrations of some persistent sub-
stances as determined by acute toxicity tests are
so low that we are not justified in allowing their
deliberate introduction into the natural environ-
ment. On the other hand, a few waste products
appear to offer little threat to the marine environ-
ment because of their rapid degradation and
dispersal.
Our concern is not primarily with what polluting
substances are present, but whether or not they are
present in sufficiently large amounts to cause dele-
terious effects on the biota and the environment.
Many naturally occurring substances, including
clean fresh water, would be toxic if discharged into
the estuarine and coastal marine environment in
sufficiently large amounts.
Determination of the toxicity of known and un-
known effluents, either simple or complex mix-
tures, can best be made by determining the reac-
tions of endemic fauna exposed to them at levels
that might be expected in receiving waters. Chemi-
cal assays may determine the presence of such pol-
lutants at levels as low as nanograms per liter, but
biological systems may be affected by even smaller
amounts. Many animals have the ability to accu-
mulate toxic residues of substances present in the
environment in only trace amounts until body resi-
dues are large enough to cause damage when re-
leased internally through normal metabolic proc-
esses. Animals differ in their sensitivity to the same
toxicant and it is essential that toxicity data be
related, in the final analysis, to animals of eco-
nomic importance.
A fundamental concept in attacking the pollu-
tion problem is the assumption that effluents con-
taining foreign materials are harmful and not per-
missible until laboratory tests have shown the
reverse to be true. It is the obligation of the agency
producing the effluent to demonstrate that it is
harmless rather than require pollution abatement
agencies to demonstrate that the effluent is causing
damage.
Specific methods are suggested here for the
determination of the toxicity of proposed effluents.
While certain procedures are desirable, they are
not always reasonable and certain permissible
alternatives are also given.
Basic Bioassay Test: The basic bioassay test
shall consist of a 96-hour exposure of an appro-
priate organism, in numbers adequate to assure
statistical validity, to an array of concentrations of
the substance, or mixture of substances, that will
reveal the level of pollution that will cause (1) ir-
reversible damage to 50 percent of the test orga-
nisms, and (2) the maximum concentration caus-
ing no apparent effect on the test organisms in
96 hours. Tests should be conducted, when pos-
sible, in a "flow-through" system so that the or-
ganisms are exposed continuously to a fresh
solution of the test material appropriately diluted
with water of the same quality as that at the site
of the proposed discharge. Adequate safeguards
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should be taken to insure that the test will be
conducted under the least favorable environmental
conditions that are allowable in the natural en-
vironment. Tests should be conducted at water
temperatures typical of the mean of maximum
daily temperatures during critical periods at the
proposed effluent discharge site.
Test organisms should be selected either on the
basis of their economic importance in the area
receiving the discharge and their sensitivity or on
the basis of their importance in the food web of
economically important animals. In the event that
organisms meeting these criteria are not suitable
or available for the confined conditions of the tests,
substitute forms endemic to the area may be uti-
lized. Appropriate tests must be undertaken to
demonstrate the relative sensitivity of economi-
cally important species and substitute species to the
test material so that meaningful interpretations of
the data can be made.
Application Factor: It is recognized that the
most obviously deleterious effect of toxic sub-
stances is increased mortality. More subtle changes
such as reduced growth, lowered fecundity, altered
physiology, and induced abnormal behavior pat-
terns may have more disastrous effects on the
continued existence of the species. Evaluations of
such sublethal effects generally will provide more
meaningful guidelines.
It is recognized that there should be an applica-
tion factor for each waste or material and that
these factors may vary widely for these different
wastes and materials. The concept and use of ap-
plication factors is denned and discussed at length
in the toxicity portion of the section on water
quality requirements for fresh water organisms.
Due to a lack of knowledge of application factors
for specific wastes and materials, a single applica-
tion factor to be applied to all wastes is being sug-
gested at this time. This application factor may
require a lower concentration than is necessary in
some instances, particularly for those materials
that are subject to biological degradation, but it is
known that it is not restrictive enough for some
materials. Ideally, the determination of application
factors should be the result of studies for the de-
termination of safe levels of potential toxicants
under long-term or continuous exposure. The ap-
plication factor is the concentration of a material
or waste that is not harmful, divided by the 96-
hour TLm value for that material. A few applica-
tion factors have been so determined at the Bureau
of Commercial Fisheries Laboratory at Gulf
Breeze, Fla. (unpublished data). In the future, as
application factors are determined for specific sub-
stances, they will replace the recommendation for
the generalized application factor for these particu-
lar materials or wastes. It is clearly understood that
as additional data become available recommenda-
tions on water quality requirements will be
changed so that they conform with the new
knowledge.
Biological Magnification: Biological magnifi-
cation is an additional chronic effect of toxic
pollutants (such as heavy metals, pesticides, radio-
nuclides, bacteria, and viruses) which must be rec-
ognized and examined before clearance can be
given for the disposal of a waste product into na-
tural waters. Many animals, and especially shellfish
such as the oyster, have the ability to remove from
the environment and store in their tissues sub-
stances present at nontoxic levels in the surround-
ing water. This process may continue in the oyster
or fish, for example, until the body burden of the
toxicant reaches such levels that the animal's
death would result if the pollutant were released
into the bloodstream by physiological activity. This
may occur, as in the case of chlorinated hydrocar-
bon pesticides (such as DDT and endrin) stored
in fat depots, when the animals food supply is re-
stricted and the body fat is mobilized. The appear-
ance of the toxicant in the bloodstream causes the
death of the animal. Equally disastrous is the
mobilization of body fat to form sex products
which may contain sufficiently high levels of the
pollutant so that normal development of the young
is impossible.
The biological magnification and storage of
toxic residues of polluting substances and micro-
organisms may have another serious after effect.
Herbivorous and carnivorous fish at lower trophic
stages may gradually build up DDT residues of
15 to 20 mg/1 without apparent ill effect. Carniv-
orous fish, mammals, and birds preying on these
contaminated fish may be killed immediately or
suffer irreparable damage because of the pesticide
residue or infectious agent.
In the final analysis, laboratory tests alone are
not sufficient to assess completely the toxic effects
of a substance. These data must be interpreted in
combination with field observations. Criteria es-
tablished under the artificial conditions of labora-
tory tests will probably require adjustment in
the light of later and more prolonged field
observations.
Recommendation: In the absence of toxicity data other
than the 96-hour TLm, an arbitrary application factor
of Vioo of this amount shall be used as the criterion of
permissible levels.
Additional chronic exposure tests will be conducted
within a reasonable period to demonstrate that the
estimated maximum safe levels as indicated by the
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96-hour TLm and the application factor do not, in fact,
cause decreases in productivity of the test species dur-
ing its life history.
Monitoring the Marine Environment: The chief
problem in monitoring the marine habitat for pol-
lution lies in the fact that the discharge of toxic
materials may be intermittent. This is not neces-
sarily true, but it means that water samples col-
lected periodically reflect only the conditions at
the time they were collected. Significantly higher or
lower levels of pollution may have existed between
sample collections. A second major factor for con-
sideration is that trace amounts of pollutants or
effluent mixtures toxic to the biota may not be
readily susceptible to chemical analysis. For these
reasons, the analysis of resident biota for abnor-
mal changes offers a better tool for interpreting
environmental fluctuations.
Mollusks are being collected for analysis at
monthly intervals in estuaries on both the Atlantic
and Pacific coasts (Butler, 1966 a, b). Analysis
of resident populations by electron capture, gas
chromatographic techniques reveal changes in
residues of 11 of the more common organochloride
pesticides which oysters, mussels, and some spe-
cies of clams readily store. These methods are use-
ful for rapid surveys of recent pollution. By appro-
priate spacing of samples in time and location, it
has been possible to pinpoint sources of pollution.
It is suggested that a monitoring system of this
type, appropriately expanded to include fish and
plankton, would quickly identify areas where pol-
lution problems exist. Suitable analytical tech-
niques are available to make these samples equally
useful for the identification of pollution by heavy
metals and other toxic substances.
Monitoring for the presence of organophosphor-
ous materials is feasible, but less specific for indi-
vidual toxic compounds. This group of pesticides
exerts its toxic effect on living systems by inhibiting
the enzyme acetylcholinesterase, which is essential
to conduction in nerve fibers. The nervous tissue of
fish and some invertebrates, appropriately ana-
lyzed, reveals whether the organism has been ex-
posed to organophosphorous materials within the
past 2 to 4 weeks (Holland, et al., 1967). Identifi-
cation of such changes can be made before toxi-
cant levels are high enough to cause serious
mortalities.
A particularly efficient nonspecific method for
monitoring changes in the estuarine habitat is
based on the periodic collection of sedentary ani-
mals and plants which have attached themselves to
artificial cultch plates. Squares of asbestos cement
boards placed in strategic locations will be utilized
by resident biota as a habitat. At 30-day or shorter
intervals these plates can be changed, the orga-
nisms enumerated, volumetrically measured or
chemically assayed, and an index of their relative
abundance obtained (Butler, 1954).
Such plates have been maintained for nearly 20
years at one laboratory in Florida (Butler, 1965),
and they supply detailed information on the rela-
tive productivity of the environment -in relation to
hydrologic changes. They will be equally useful as
monitors of newly introduced pollutants in this
area. The monitoring method of choice—and there
are others besides the ones suggested—will depend
on the specific environment and the animals of
particular interest. No one method will be adequate
and a combination of methods should provide the
most information in the shortest time period.
Pesticides: Pesticides may be described as na-
tural and synthetic materials used to control un-
wanted or noxious animals and plants. They exert
their effect as contact or systemic poisons, as repel-
lents, or in some cases as attractants. It is conveni-
ent to classify them according to their major usage
such as fungicides, herbicides, insecticides, fumi-
gants, and rodenticides. Although data are not
available as to the total amount of pesticides used
in the United States, total production figures (in-
cluding exports) show that more than 875 million
pounds were produced in 1965. This represents an
increase of approximately 10 percent over 1964,
and more than a fivefold increase in the past two
decades. In recent years, the use of herbicides has
increased relatively more rapidly than that of other
pesticides. In 1964, more than 100 million acres of
the continental United States were treated with
some kind of pesticide. The trend in pesticide pro-
duction is towards the manufacture of more granu-
lar formulations. This physical adsorption of the
pesticide on clay particles makes possible better
control during application and should result in less
dissipation of the chemical into atmosphere and
into nontarget areas.
Despite better control of pesticide applications,
their dispersal in drainage systems and possible
eventual accumulation in estuaries makes our
coastal fisheries especially vulnerable to their toxic
effects. Estuarine oyster populations, juvenile
shrimp, crab, and menhaden, for example, all
occupy the habitat where fresh and salt water mix
and where deposition of river silt with its load of
adsorbed pollutants takes place. Laboratory tests
show that these economically important animals
are especially sensitive to the toxic effects of low
levels of pesticides. Oysters, for example, will exist
in the presence of DDT at levels as high as 0.1
mg/1 in the environment. But at levels 1,000 times
less (0.1 fig/1), oyster growth or production
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would be only 20 percent of normal, shrimp popu-
lations would suffer a 20-percent mortality, and
menhaden would suffer a disastrous mortality.
Some insecticides are toxic enough to kill 50 per-
cent or more of shrimp populations after 48 hours
exposure to concentrations of only 30 to 50 nano-
grams per liter of the compound.
Pesticides may be classified by their chemical
affinities and a large number of economically im-
portant insecticides are chlorinated hydrocarbon
compounds. These include the well-known DDT
and aldrin-toxaphene group. Typically, these are
persistent compounds, but they may be degraded
by living systems into less toxic metabolites. As
residues in soil and marine sediments, they may
persist unchanged for many years and conse-
quently present a continuing threat to animal
communities. As a general rule, the acute toxicity
of this group of pesticides increases with the level
of metabolic activity so that their presence may
cause two or three times more damage in summer
than in winter months.
The organophosphorous pesticides are also pri-
marily insecticides. Typically, they hydrolyze or
break down into less toxic products much more
readily than the organochloride compounds. Prac-
tically all persist for less than a year, while some
last only a few days in the environment. Most of
them are degraded rather quickly in warm water
and consequently are more hazardous to aquatic
animals at winter rather than summer tempera-
tures. They exhibit a wide range of toxicity, both
more and less damaging to marine fauna than the
organochlorides. They are usually preferable as
control agents because of their relatively short life.
Other major chemical categories including the
carbamates, arsenicals, and 2,4-D and 2,4,5-T
compounds are generally, but not necessarily, less
toxic to marine biota.
Pesticides registered for uses which might per-
mit their dispersal into the marine environment
must be evaluated for their toxic effect on oysters,
fish, and shrimp. Consequently, there is a con-
siderable amount of information on the 48 or 96-
hour TLra values of these compounds. Unfortu-
nately, information is still lacking on their long-
term effects at sublethal levels on the productivity
of economically important marine species.
The extreme sensitivity of marine crustaceans,
such as crabs, lobsters, and shrimp, to the array of
insecticides is to be expected because of their phy-
logenetic relationship with terrestrial arthropods.
In general, shrimp are also much more sensitive
than fish or oysters to the other pesticides. This fact
and their economic importance make shrimp a
valuable yardstick for establishing safe levels of
pesticides that might be expected as toxicants in
the marine environment.
A much broader spectrum of pesticide pollutants
can be anticipated in the fresh water (salinity
<0.5 %0) zones of tidal estuaries. Fresh water
criteria listed in another section will apply under
these circumstances.
Recommendation: The pesticides are grouped accord-
ing to their relative toxicity to shrimp, one of the most
sensitive groups of marine organisms. Criteria are based
on the best estimates in the light of present knowledge
and it is expected that acceptable levels of toxic ma-
terials may be changed as the result of future research.
Pesticide group A.—The following chemicals are
acutely toxic at concentrations of 5 jug/1 and less. On
the assumption that Hoo of this level represents a rea-
sonable application factor, it is recommended that en-
vironmental levels of these substances not be permitted
to rise above 50 nanograms/1. This criterion is so low
that these pesticides could not be applied directly in
or near the marine habitat without danger of causing
damage. The 48-hour TLm is listed for each chemical
in parts per billion (fig/I).
Organochloride pesticides
Aldrin 0.04
BHC 2.0
Chlordane 2.0
Endrin 0.2
Heptachlor 0.2
Lindane 0.2
DDT 0.6
Dieldrin 0.3
Endosulfan 0.2
Methoxychlor 4.0
Perthane 3.0
TDE 3.0
Toxaphene 3.0
Organophosphorous pesticides
Coumaphos 2.0 Naled 3.0
Dursban 3.0
Fenthion 0.03
Parathion 1.0
Ronnel 5.0
Pesticide group B.-—-The following types of pesticide
compounds generally are not acutely toxic at concen-
trations of 1 mg/1 or less. It is recommended that an
application factor of Hoo be used and, in the absence of
acute toxicity data that environmental levels of not
more than 10 Mg/1 be permitted.
Arsenicals
Botanicals
Carbamates
2,4-D compounds
2,4,5-T compounds.
Phthalic acid compounds.
Triazine compounds.
Substituted urea compounds.
Other pesticides.—Acute toxicity data are available
for approximately one hundred technical grade pesti-
cides in general use not listed in the above groups. These
chemicals either are not likely to reach the marine en-
vironment, or, if used as directed by the registered
label, probably would not occur at levels toxic to marine
biota. It is presumed that criteria established for these
chemicals in fresh water will protect adequately the
marine habitat. It should be emphasized that no un-
listed chemical should be discharged into the estuary or
coastal water without preliminary biossay tests and the
establishment of an adequate application factor.
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Heavy Metals: Heavy metal salts in solution
may constitute a very serious form of pollution
because they are stable compounds, not readily
removed by oxidation, precipitation, or any other
natural process. A characteristic feature of heavy
metal pollution is its persistence in time as well as
in space for years after the pollutional operations
have ceased.
The number of substances that may be described
as "poisonous" is very large and they vary enor-
mously in the degree of their effect. For man and
other air-breathing animals, the threshold dose of
a toxic material generally means the maximum
quantity that can be taken without causing death.
For aquatic animals living in a water environment
containing a toxic substance, the situation is some-
what different. Instead of receiving an absolute
quantity at one time, they are being continually
exposed to a given concentration of the toxic mate-
rial. This is similar to a man regularly drinking
water containing lead or breathing air containing a
noxious gas or vapor. It is not surprising, therefore,
that the student of pollution problems turns his at-
tention toward the concentration of the poison he
is investigating and the manner in which the effect
is related to this, rather than to the absolute
amount required to harm or kill. Animals have the
ability to eliminate poisons at least to some degree
or even to destroy them. Their ability to do this at
a rate permitting survival depends on the concen-
tration of the toxic material to which they are
exposed.
One of the characteristics of living cells is their
ability to take up elements from a solution against
a concentration gradient. This is perhaps most ob-
vious for marine organisms, especially for auto-
trophic algae which obtain all their nutrients di-
rectly from seawater. The ability of marine
organisms to concentrate elements above that level
found in their environment has been recognized
for some time. The following points should be
noted in relation to their concentrating ability.
(1) All elements are concentrated to a degree
with the exception of chlorine, which is rejected,
and sodium, which is weakly rejected. The concen-
tration factors are of the order of one for bromine,
fluorine, magnesium, sodium, and sulfur, and
higher for all other elements.
(2) Among cations (including metallic ele-
ments such as iron, which may exist as colloids in
the sea), the order of affinity for living matter is,
generally: tetravalent and trivalent elements>di-
valent transition elements > divalent group II-A
metals >univalent group I metals. The tetravalent
and trivalent subgroup have rather different affini-
ties for plankton and brown algae.
plankton: Fe>Al>Tl>Cr, Si>Ga
brown algae: Fe>La>Cr>Ga>Li>Al>Si
Similar differences are found between these orga-
nisms in their affinities for the divalent transition
metals.
plankton: Zn>Pb>Cu>Mn>Co>Ni>Cd
brown algae: Pb>Mn>Zn>Cu, Cd>Co>Ni
Of interest is the affinity of both organisms for lead,
which has no known biological function.
It is clear that the heavier elements in these
groups tend to be more readily taken up than the
lighter ones, which may be connected with their
greater, ease of polarization.
(3) The order of affinity of living matter for
anions is:
nitrate > trivalent anions > divalent anions >
univalent anions
It is probable that most polyvalent metallic1 ele-
ments are more or less chelated by organic matter.
The main features of the uptake of ions by cells
can be accounted for by assuming that another
process operates apart from simple diffusion. This
process is called active uptake and is closely linked
with metabolic activities within the cell. The meta-
bolic processes provide the energy necessary for
the uptake against a concentration gradient. Active
uptake has a larger temperature coefficient than
does uptake by diffusion. In long-term experi-
ments, the effect of temperature is probably com-
plicated by increased rates of growth, cell division,
and so on. Active uptake requires oxygen and oc-
curs only in cells which are respiring freely. Sub-
stances which inhibit respiration also inhibit up-
take of ions. The rate of uptake of ions may be
limited either by the rate of exchange at the cell
membrane or by bulk phase diffusion inside the
cell. The former is usually limiting for ions present
at low external concentration and the latter for
ions at high external concentrations. It has been
suggested that bulk phase diffusion limits the rates
of uptake of most cations. There appears to be at
least two active transport systems in addition to
the diffusion processes. A large number of theories
have been advanced to explain active transport.
One of the most popular is the carrier hypothesis.
Accordingly, the ions are transported across mem-
branes as chelates with metabolically produced or-
ganic molecules.
Uptake by invertebrate animals.—The most
primitive animals, the unicellular protozoa, take
up ions from solution by diffusion in the same
ways as do algae. Many marine species have
vacuoles and these are able to open at intervals
and extrude fluid from the cell. The vacuole regu-
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lates the osmotic pressure of the cell and thus con-
trols its volume.
Multicellular invertebrate animals can be di-
vided into two groups as far as uptake is con-
cerned: those with permeable integuments and
those without. The majority of marine inverte-
brates (colenterates, annelids, mollusks, and
echinoderms) have soft bodies with permeable
integuments through which ions can diffuse freely.
In this situation, the body fluid or blood is quite
similar to sea water in composition. The gills of
mollusks are coated with a layer of complex carbo-
hydrate sulfates which may function as ion ex-
changers. The gills of marine Crustacea, which
have hard impermeable carapaces, are fully per-
meable to water and salts.
Mode of toxic action.—An element is said to be
toxic if it injures the growth or metabolism of an
organism when supplied above a certain concen-
tration. All elements are toxic at high concentra-
tions and some are notorious poisons even at low
concentrations. For example, the essential micro-
nutrient, copper, which is a necessary constituent
of all organisms, is highly toxic at quite small con-
centrations. The other essential micronutrients are
also toxic when supplied in excess, though not all
in such striking fashion. There is an optimum range
of concentration, which is sometimes quite narrow,
for the supply of each element to each organism.
When excessive amounts of an element are fed
to an organism, they frequently cause death. The
usual measure of the amount required to cause
death is called the LD00, This is the amount which,
when fed to each individual in a population, kills
half of the population. The LDr,0 is an imprecise
measure unless it is qualified by specifying:
(1) The chemical state of the element.
(2) The means of feeding.
(3) The age or developmental stage of the
organism.
(4) The time elapsed between feeding and
death.
The most important mechanism of toxic action
is thought to be the poisoning of enzyme systems.
The more electronegative metals, notably copper,
mercury, and silver, have a great affinity for amino,
imino, and sulfhydryl groups which are doubtless
reactive sites on many enzymes. These metals are
readily chelated by organic molecules. We thus
have discovered attempts to correlate metal toxi-
cities with such factors as their electronegativities,
the insolubility of their sulfides, or the order of
stability of their chelated derivatives:
(1) Order of electronegativities of some diva-
lent metals: Hg > Cu > Sn > Pb > Ni > Co >
Cd>Fe>Zn>Mn>Mg>Ca>Sr>Ba
(2) Order of stability products of the sulfides:
Hg>Cu>Pb>Cd>Co>Ni>Zn>
Fe>Mn>Sn>Mg>Ca
(3) Order of stability of chelates: Hg>Cu>
Ni >Pb>Co>Zn>Cd >Fe>Mn >Mg>
Ca.
It appears likely that all the divalent transition
metals, as well as the other electronegative metals,
that form insoluble sulfides, such as Ag, Mo, Sb,
Tl, and W, are poisons by virtue of their reactivity
with proteins and especially with enzymes. In view
of the large number of enzymes in living cells, the
variations in toxicity indicated above are hardly
surprising. Studies have shown that metals giving
rise to similar toxic effects may be acting on quite
unrelated enzymes and also many more atoms of
metal are absorbed by an inactivated enzyme than
are required to block the reactive sites. Other
modes of toxic action are:
(1) Substances behaving as antimetabolites.
This might be arsenate and chlorate occu-
pying sites for phosphates and nitrates,
respectively. (Fluoride, borate, bromate,
permanganate, antimonate, selenate, tellu-
rate, tungstate, and beryllium.)
(2) Substances forming stable precipitates or
chelates with essential metabolites. (Al,
Be, Sc, Ti, Y, Zr, reacting with phosphate,
Ba with sulfate, or Fe with ATP.)
(3) Substances catalyzing the decomposition of
essential metabolites. (La and other lan-
thanide cations decompose ATP.)
(4) Substances combining with the cell mem-
brane and affecting its permeability. (Au,
Cd, Cu, Hg, Pb, U.) These elements may
affect transport of sodium, potassium,
chlorine, or organic molecules across mem-
branes or even rupture them.
(5) Substances replacing structurally or elec-
trochemically important elements in the
cell and then failing to function. (Li replac-
ing Na, Cs replacing K, or Br replacing
Cl.)
Metal-organic compounds may be either more
toxic than the metal ion (ethyl mercuric chloride)
or much less so (cupric ion and copper salicyl-
aldoxime).
Silver.—Silver is present in seawater in a con-
centration of about 0.0003 mg/1. It is found in
marine algae at concentrations up to 0.25 mg/1
and in marine mammals in the range of 1 to 3 mg/1
(Vinogradov, 1953). It is highly toxic to plants
and mammals.
Arsenic.—Arsenic is found to a small extent in
nature in the elemental form. It occurs mostly in
the form of arsenites of true metals or as pyrites.
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Its major commercial use is for pesticides (insects,
weeds, fungi). Arsenic is cumulative in the tissues
of many organisms and, therefore, it eventually
exerts its effects even though the environmental
level is low. It has been demonstrated to be a pos-
sible carcinogen in water.
Arsenic is found in seawater at a concentration
of about 0.003 mg/1. It has been found in marine
plants at concentrations up to 30 mg/1 and is high-
est in the brown algae. It is found in marine ani-
mals in a range of 0.005 to 0.3 mg/1. It is accumu-
lated by coelenterates, some mollusks, and
crustaceans (Vinogradov, 1953). It is moderately
toxic to plants and highly toxic to animals especi-
ally as AsH3.
Arsenic trioxide, which also is exceedingly toxic,
was studied in concentrations of 1.96 to 40 mg/1
and found to be harmful to fish or other aquatic
life. Work by the Washington Department of Fish-
eries (1944) on pink salmon has shown that at a
level of 5.3 mg/1 of As2O3 for 8 days was extremely
harmful to this species. Ellis (1937), using the
same compound on mussels at a level of 16 mg/1,
found it to be quite lethal in 3 to 16 days. Surber
and Meehan (1931) carried out an extensive study
on the toxicity of As2O3 to many different fish food
organisms. Their results indicated that important
fish food organisms can tolerate an application rate
of 2 mg/1 of As2O3. The amount actually in the
water is considerably less.
Cadmium.—The elemental form of cadmium
is insoluble in water. It occurs largely as the sulfide
which is often an impurity in zinc ores.
Cadmium is found in seawater at a level of less
than 0.08 mg/1. Its level in marine plants is ap-
proximately 0.4 mg/1, while in marine animals a
range of 0.15 to 3 mg/1 has been found. It is low-
est in the calcareous tissues and is accumulated
within the viscera of the mollusk, Pecten novazet-
landicae (Brooks and Rumsby, 1965). Cadmium
is moderately toxic to all organisms and it is a
cumulative poison in mammals.
Cadmium is used widely industrially to alloy
with copper, lead, silver, aluminum, and nickel. It
is also used in electroplating, ceramics, pigmenta-
tion, photography, and nuclear reactors. Cadmium
salts sometimes are used as insecticides and anti-
helminthics. The chloride, nitrate, and sulfate of
cadmium are highly soluble in water. The carbo-
nate and hydroxide are insoluble, thus cadmium
will be precipitated at high pH values.
Most quantitative data on the toxicity of cad-
mium are based on specific salts of the metal. Ex-
pressed as cadmium, these data indicate that the
acute lethal level for fish varies from about 0.01 to
about 10 mg/1 depending on the test animal, the
type of water, temperature, and time of exposure.
Cadmium acts synergistically with other substances
to increase toxicity. Concentrations of 0.03 mg/1
in combination with 0.15 mg/1 zinc causes mor-
tality of salmon fry (Hublou, et al., 1954).
Pringle (in press), in a study of adult American
Eastern oysters, Crassostrea virglnica, found an 8-
week TLm value of 0.2 mg/1 of Cd«[Cd(NO3)2]
and a 15-week TLm value of 0.1 mg/1.
The most obvious effect, in addition to lethality,
was lack of shell growth. A similar study on the
clam, Mercenaria mercenaria, indicated that a
much longer period of exposure at the same con-
centration was required to kill half of the test
organisms.
Chromium.—Chromium is found in seawater at
a concentration of 0.00005 mg/1. Marine plants
contain approximately 1.0 mg/1 while marine ani-
mals contain chromium within a range of 0.2 to
1.0 mg/1. Chromium compounds may be present
in wastes from many industrial processes or they
may be discharged in chromium-treated cooling
waters. The toxicity of chromium varies with the
species, temperature, pH, its valence, and synergis-
tic or antagonistic effects (especially with hard-
ness). Most evidence points to the fact that under
long-term exposure the hexavalent form is no more
toxic towards fish than the trivalent form. Doudor-
off and Katz (1953), studied the effect of K2Cr2Or
on mummichaugs and found that they tolerated a
200 mg/1 level in sea water for over a week.
The effects of hexavalent chromium on photo-
synthesis by the giant kelp, Macrocystis pyrifera,
were as follows: at 1 mg/1 chromium, photosyn-
thesis was not diminished by 2 days contact. It
was reduced 10 to 20 percent by 5 days contact
and 20 to 30 percent after 7 to 9 days. The con-
centration of chromium required to cause a 50-per-
cent inactivation of photosynthesis in 4 days was
estimated at 5 mg/1 (Clendenning and North,
1958, 1960; North and Clendenning, 1958, 1959).
Haydu (unpublished data) studied oyster mor-
talities and his results point out the long-term ef-
fects of low concentrations of chromium, molybde-
num, and nickel. The levels of all three metals were
in the range of 10 to 12 p,g/\ over a 2-year period.
In addition, his data indicated that there were sea-
sonal variations. The mortalities at these levels in«
creased with an increase in temperature. Approxi-
mately 63 to 73 percent of the mortalities occurred
in the period of May through July, perhaps due to
increased physiological activity (increased feeding
and higher pumping rates).
This study substantiates the available evidence
indicating that as the environmental level of these
metals increases, the ingestion-elimination balance
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is upset, causing accumulation to take place.
Raymont and Shields (1964), in studies with
the small prawn, Leander squilla, found a thresh-
old level of a little less than 5 mg/1 Cr. Thus, at
chromium concentrations ranging from 10 to 80
mg/1 Cr, 100-percent mortality occurred in 1
week; at 5 mg/1 Cr no deaths occurred in 1 week
although a few animals died over the subsequent
21 days. Larger prawns of the same species ap-
peared to be considerably more resistant to chro-
mium poisoning. The threshold was about 10 mg/1
Cr. Raymont and Shields in additional experiments
on the toxicity of chromium to crustaceans (the
shore crab, Carcinus maenas), indicated that chro-
mium concentrations above 50 mg/1 (Na2CrO4)
were definitely toxic for a period of exposure of
12 days. At 60 mg/1 Cr, 50-percent mortality oc-
curred after 12 days. At 40 mg/1 Cr, 9 percent
died within 12 days, while at 20 mg/1, an 8-percent
mortality was observed. In studies on the marine
polychaete worm, Nereis virens, these same inves-
tigators working in the range of 2 to 10 mg/1 Cr
found that there was heavy mortality with all solu-
tions in 2 to 3 weeks. The threshold of toxicity ap-
pears to be at about 1.0 mg/1 Cr level.
Pringle (in press), in experiments using a well-
controlled, flow-through system and chromium
concentrations of 0.1 and 0.2 mg/1 (Na2Cr2O7),
showed the average weekly mortality to be ap-
proximately 1 percent over a 20-week period. This
was about the same as that for the sea water
controls.
Copper.—Copper is found in seawater at a level
of 0.003 mg/1. It is found in marine plants at
about 11 mg/1, while marine animals are found to
contain 4 to 50 mg/1. It is accumulated by some
sponges and is essential for the respiratory pig-
ment in the blood of certain annelids, Crustacea,
and mollusks. In excess, it is highly toxic to algae,
seed plants, and to invertebrates and moderately
toxic to mammals. Copper is not considered to be
a cumulative systemic poison like lead or mercury.
The toxicity of copper to aquatic organisms
varies significantly not only with the species but
also with the physical and chemical characteristics
of the water. Copper acts synergistically with zinc,
cadmium, and mercury, yet there is a sparing
action with calcium.
Barnacles and related marine fouling organisms
were killed in 2 hours by 10 to 30 mg/1 copper.
Clarke (1947) showed that the mussel, Mytilus
edulis, was killed in 12 hours by 0.55 mg/1. Lob-
sters transferred to tanks lined with copper after
living in aluminum, stainless steel, and iron tanks
for 2 months, died within 1 day. Copper is concen-
trated by plankton from surrounding water in
ratios of 1,000 to 5,000 or more (Krumholz and
Foster, 1957).
Concentrations of copper above 0.1 to 0.5
mg/1 were found to be toxic to oysters by Galtsoff
(1932). The 96-hour TLm for oysters was esti-
mated at 1.9 mg/1 (Fujiya, 1960). Oysters cul-
tured in waters containing 0.13 to 0.5 mg/1 ac-
cumulated copper in their tissues and became unfit
as a food substance. Pringle (in press) found the
soft clam, Mya arenaria, extremely sensitive to
copper. At a concentration of 0.5 mg/1, 100-per-
cent mortality took place in 3 days. Using a 0.2
mg/1 concentration at 10 and 20 C, all clams died
within 23 days at the lower temperature, while at
the higher temperature all succumbed in 6 to 8
days. When 0.1 mg/1 Cu at 20 C was used, all
animals died in 10 to 12 days. Raymont and
Shields (1964) in studies with the marine poly-
chaete worm Nereis, showed that a concentration
of 1.5 mg/1 Cu was lethal in 2 to 3 days, and con-
centrations exceeding 0.05 mg/1 Cu were lethal in
approximately 4 days.
Clendenning and North (1958, 1960) and
North and Clendenning (1958, 1959) evaluated
the effect of copper (from the chloride and sulfate
salts) on the rate of photosynthesis of the giant
kelp, Macrocystis pyrifera. With 0.1 mg/1 of cop-
per, net photosynthesis was inhibited by 50 percent
in 2 to 5 days and 70 percent in 7 to 9 days. Visi-
ble injury appeared in 10 days. Copper was
slightly less toxic than mercury but more so than
nickel, chromium, lead, or zinc. Marvin, Lansford,
and Wheeler (1961) found 0.05 mg/1 Cu toxic to
Gymnodinium breve (red tide organism).
Mercury.—Mercury is found in seawater at a
level of 0.00003 mg/1. It is found in marine plants
at approximately 0.03 mg/1.
Irukayama (1966) reported on a mercurial pol-
lution incident in Japan, which was first recognized
in 1953. A severe neurological disorder resulted in
the area^of Minamata Bay as a result of eating fish
and shellfish from these waters. Many species of
animals including waterfowl were succumbing to
the "disease" called Minamata disease. Clinical
features were cerebellar ataxia, constriction of vis-
ual fields, and dysarithia. Pathological findings
were regressive changes in the cerebellum and
cerebral cortices. Investigation through 1965 sug-
gested that the main cause was the spent factory
waste of the Kanose Factory upstream from the
Minamata Bay area. Methyl mercury compounds,
waste byproducts from the acetaldehyde synthesis
process, were being discharged and concentrated
especially in shellfish.
Ukeles (1962) made a study of pure cultures of
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marine phytoplankton in the presence of toxicants.
One of the toxic materials used was lignasan
(ethyl mercury phosphate) a bactericide-fungi-
cide. She found lignasan to be lethal to all species
at 0.06 mg/1 and 0.0006 was the highest level used
not causing drastic inhibition of growth.
Clendenning and North (1960) and North and
Clendenning (1958) found that 0.5 mg/1 of mer-
cury added as mercuric chloride caused a 50-per-
cent inactivation of photosynthesis of the giant
kelp, Macrocystis pyrijera, during a 4-day expo-
sure. A concentration of 0.1 mg/1 caused a 15-
percent decrease in photosynthesis in 1 day and
complete inactivation in 4 days. Mercury was more
toxic than copper, hexavalent chromium, zinc,
nickel, or lead. For phytoplankton, the minimum
lethal concentration of mercury salts has been re-
ported to range from 0.9 to 60 mg/1 of mercury
(Hueper, 1960). The toxic effects of mercury salts
are accentuated by the presence of trace amounts
of copper (Corner and Sparrow, 1956).
Lead.—Lead is found as a local pollutant of
rivers near mines and from the combustion of
leaded gasolines. The lead concentration in sea-
water is in the order of 0.00003 mg/1. It is found
in marine plants at a level of approximately 8.4
mg/1. Residues in marine animals reach a concen-
tration in the range of 0.5 mg/1. It is highest in
calcareous tissue.
Wilder (1952) found that lobsters died within
20 days when kept in lead-lined tanks, while in
steel-lined and other types of tanks, they survived
for 60 days or longer.
North and Clendenning (1958) found that lead
was less toxic to the giant kelp, Macrocystis pyri-
jera, than mercury, copper, hexavalent chromium,
zinc, or nickel.
Pringle (unpublished data), in studies on the
effects of lead on the Eastern oyster, Crassostrea
virginica, found a 12-week TLm value of 0.5 mg/1
and an 18-week TLm value of 0.3 mg/1. Concen-
trations of 0.1 to 0.2 mg/1 induced noticeable
changes in mantle and gonadal tissue under 12
weeks of exposure.
Nickel.—Nickel is found in sea water in a con-
centration of about 0.0054 mg/1. Marine plants
contain up to 3 mg/1 and this may be higher in
plankton. Marine animals contain levels in the
range of 0.4025 mg/1. Nickel pollution is caused
by industrial smoke and other wastes. It is very
toxic to most plants but less so to animals. Haydu
(unpublished data), in long-term studies with oys-
ters, found that a level of 0.121 mg/1 nickel
caused considerable mortality.
Zinc.—Zinc is found in sea water in a concen-
tration of 0.01 mg/1. Marine plants may contain
up to 150 mg/1 of zinc. Marine animals contain
zinc in the range of 6 to 1500 mg/1. It is accumu-
lated by some species of coelenterates and mol-
lusks. Speer (1928) reports that very small
amounts of zinc are dangerous to oysters.
Clendenning and North (1960) and North and
Clendenning (1958) tested the effect of zinc sul-
fate on the giant kelp, Macrocystis pyrijera. Four-
day exposure to 1.31 mg/1 of zinc snowed no ap-
preciable effect on the rate of photosynthesis, but
10 mg/1 caused a 50-percent inactivation of kelp.
Other Toxicants
Ammonia-ammonium compounds.—Ammonia
is found in the discharge of many industrial wastes.
It has been shown that at a level of 1.0 mg/1 NH3,
the ability of hemoglobin to combine with oxygen
is impaired and fish may suffocate. Evidence indi-
cates that ammonia exerts a considerable toxic ef-
fect on all aquatic life within a range of less than
1.0 mg/1 to 25 mg/1, depending on the pH and
dissolved oxygen level present.
Cyanides.—Hydrocyanic acid or hydrogen cya-
nide and its salts, the cyanides, are important in-
dustrial chemicals. The acid and its salts are
extremely poisonous.
Hydrogen cyanide is largely dissociated at pH
levels above 8.2 and its toxicity increases with a
decrease in pH. The toxic action of cyanides in-
creases rapidly with a rise in temperature.
Fish can recover from short exposure to con-
centrations of less than 1.0 mg/1 (which seems to
act as an anaesthetic) when removed to water free
of cyanide. They appear to be able to convert cya-
nide to thiocyanate, an ion that is not inhibitory
on the respiratory enzymes. Complex cyanides
formed by the reaction of CN with zinc or cad-
mium are much more toxic. However, the reaction
between CN and nickel produces a cyanide com-
plex less toxic than the CN itself at high pH levels.
Sulfidcs.—Sulfides in water are a result of the
natural processes of decomposition, sewage, and
industrial wastes such as those from oil refineries,
tanneries, pulp and paper mills, textile mills,
chemical plants, and gas manufacturing facilities.
Most toxicity data available are based on fresh
water fish. Concentrations in the range of less than
1.0 mg/1 to 25.0 mg/1 are lethal in 1 to 3 days.
Fluorides.—Fluorides are present in varying
amounts in the earth's crust. They are used as in-
secticides as well as in water treatment and many
other uses. While normally not present in industrial
wastes, they may be present in trace or higher con-
centrations due to spillage. Data in fresh water in-
dicate that they are toxic to fish at concentrations
higher than 1.5 mg/1.
Detergents and surfactants.—During the past
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twenty years, synthetic detergents have replaced
a majority of the soap products. Concern about
their importance in pollution was heightened by
the visible evidence of their foaming in the Na-
tion's waterways. Their toxicity to the aquatic
fauna has been very extensively studied, but for
the most part it is difficult to establish safe criteria
because of the varying conditions of the tests. Rela-
tively little bioassay work on their effects on marine
biota has been published, but it is indicated that,
unlike soap, detergents are more toxic in highly
saline water than they would be in the fresh water
areas of tidal estuaries (Eisler, 1965; Eisler and
Derrel, 1966).
The 96-hour TLm values of an ABS detergent
to five species of marine fish ranged from 7 to
22 mg/1 (Eisler, 1965). Marine kelp were more
sensitive and photosynthesis was inhibited 50 per-
cent after 96-hour exposures to about 1.0 mg/1.
Pathogenic organisms.—Oysters, clams, and
mussels have a demonstrated ability to accumulate
microorganisms, including bacteria and viruses,
from their aquatic environments and to serve as
a vehicle for the transmission of these micro-
organisms to their consumers (U.S. DHEW, 1956,
1958, 1962, 1965a;Liu, et al., 1967).
Controls to prevent the transmission of disease
through this route have been provided in the
United States through the National Shellfish Sani-
tation Program (NSSP) administered by the Pub-
lic Health Service, Department of Health, Educa-
tion, and Welfare on the behalf of the interested
State and Federal agencies and the shellfish in-
dustry (1965b). This program has established
bacteriological quality standards for those waters
from which shellfish are to be harvested for direct
marketing. These standards, as described in the
NSSP Manual of Operation, should be observed
for those estuarine areas used for commercial pro-
duction of shellfish for direct marketing (U.S.
DHEW, 1965). The standards that are applied to
shellfish harvesting areas have been revised peri-
odically through the mechanism of a shellfish sani-
tation workshop held at 2 or 3-year intervals. As
these standards are revised so should the water
quality criteria be modified.
Tar, gas, and coke wastes.—The distillation of
coal for the production of gas, coke, and tarry ma-
terials used in the manufacture of dyes and vari-
ous organic chemicals results in a watery waste
known as ammoniacal gas liquor, the disposal of
which can cause detrimental effects. Ammoniacal
gas liquor contains free ammonia, ammonium
salts, cyanide, sulfide, thiocyanate, and a variety
of aromatic compounds including pyridine,
phenols, cresols, xylenols, and aromatic acids.
After treatment to remove ammonia, the waste is
called "spent gas liquor." Phenol or carboxylic
acid is the most abundant of its many phenolic
substances, probably the most dangerous to fish.
Phenolic substances are also present in materials
used in road surfacing, sheep dips, and many in-
dustrial wastes such as those associated with the
manufacture of plastics, dyes, and disinfectants.
Gas liquor, discharged untreated to a stream, has
an extremely high oxygen demand, many times
greater than that of sewage. These various groups
of organic substances produce a variety of effects
on fish varying from intoxication and anaesthesia
to paralysis and death.
Pure compounds representative of these groups
found in such coal tar wastes have been shown to
be toxic in ranges of 2 to 75 mg/1 for cresols and
0.1 to 50 mg/1 for phenols, for fresh water fish
and lower aquatic life.
Petroleum refining and petrochemical wastes.—
The volatile components of petroleum consist
mainly of aliphatic hydrocarbons. In addition to
paraffins and olefins, some petroleums contain
relatively high percentages of naphthenes and
aromatic hydrocarbons. The less volatile fractions
of petroleum are used as fuels, lubricants, and
construction materials (asphalt). These substances
are somewhat more irritating to the skin and some
are carcinogenic, but less so than coal tar products.
Pulp and paper manufacturing wastes.—The
types of pulp produced and pulping technology
have undergone considerable change in the last
20 years and the trend continues. Modern pulp-
mills are geared to produce a variety of pulp
grades due to the increasing demands for specialty
products. The characteristics of the waste waters
from these specialty pulp grades can vary con-
siderably. An example of this can be seen in the
BOD loadings of the following sulfite grade pulps
produced in a west coast mill:
Paper making—130 lb BOD/ADT (air dry
ton).
Alpha hardwood—300 Ib/ADT.
FAC-SAC—450 Ib/ADT.
The major pulping processes include kraft, sul-
fite, semichemical, and nonchemical such as
groundwood. The kraft process accounts for ap-
proximately 75 percent of the total pulp produc-
tion in the United States. The number of mills
using the sulfite process are declining, some are
being converted to the kraft process.
From the standpoint of water pollution, kraft
and sulfite mills are of great significance. The prin-
cipal problems associated with pulpmill wastes are
toxicity, depressed DO's, and slime growths. Clear-
cut cases of acute toxicity attributable to pulpmill
wastes in modern times seldom exist except when
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spills or other accidents occur. It is much more
common to encounter problems related to slime
growths, depressed DO's, and to long-term or
chronic effects on the biota.
A substantial portion of pulpmill wastes includ-
ing the toxic components are very amenable to
microbial degradation. In one study, kraft mill
wastes were found to be nontoxic to oysters at a
dilution of 1:20 when the BOD of the waste was
reduced by 80 percent employing biological treat-
ment. In a similar study, the toxicity of kraft
wastes to silver salmon was found to diminish pro-
portionally to the degree of BOD reduction above
50 percent, again using biological treatment. The
results of a recent study by scientists of the Inter-
national Pacific Salmon Commission indicate a
fairly close relationship between BOD reduction
and decrease in the toxicity of kraft wastes. They
found no apparent toxicity to salmon when the
BOD was reduced by 65 percent. While similar
studies have not been made with sulfite liquors,
there is some evidence that the toxic components
of this waste are also degradable. It is important to
recognize that the biological mechanism or degra-
dation involved in secondary treatment is essen-
tially similar to that in receiving waters. Given
sufficient time, the process of degradation of the
toxic components of pulp wastes also take place in
receiving waters.
Because of the great complexity and variability
of pulpmill wastes, it is difficult to find a satisfac-
tory expression for concentration. Attempts have
been made to relate toxicity to BOD, COD, total
solids, FBI (Pearl Benson Index—a measure of
the lignin content of pulp wastes), and various
reference animals. There is a general relationship
with all of these criteria; i.e., the higher the values,
the greater the toxicity. Pulpmill dosages or dilu-
tions have been used in bioassays on the basis of
applied initial BOD. The response of the test ani-
mals has been found to vary considerably to given
concentrations of applied BOD even from the
wastes of the same mill. This would indicate that
the concentration of toxicants in the total biolog-
ically amenable fraction is subject to considerable
variation. This would not only explain the lack of
a good relationship between the toxicity and initial
BOD, but it would also explain why, on the other
hand, there can coexist a good relationship be-
tween BOD reduction and reduction in toxicity.
The latter is subject to degradation regardless of
the proportions of toxicants and the other to bio-
degradable substances.
The shortcomings of BOD as an expression of
the concentration of toxicity would seem to be
equally applicable to the PBI test. This test has
been recommended as a measure of SWL (sulfite
waste liquor) concentration. It measures the
lignins in SWL which constitute an appropriate
substance for tracing in receiving waters and for
analysis due to their stability and high concentra-
tions. As indicated earlier, critical tests to deter-
mine the relationship between BOD reduction and
reduction in toxicity have not been conducted with
SWL. Nevertheless, there is sufficient evidence to
indicate that the toxic components of SWL also
reside in the biodegradable fraction and are also
degradable. The composition of SWL in receiving
waters at different distances from the point of dis-
charge would therefore differ even though similar
PBI values may occur. The toxicity of fresh SWL
at a PBI concentration of 50 mg/1 would be much
greater than of biologically stabilized SWL at the
same PBI concentration. There is clear indication
that further study of SWL toxicity and biodegrada-
tion is necessary.
The toxicity of kraft and sulfite wastes to
aquatic life is amply reported in the literature.
Deleterious effects produced by SWL (generally
considered less toxic than kraft wastes) are re-
ported from PBI values as low as 2.0 mg/1 for
oyster larvae to concentrations greater than 1,000
mg/1 for the adult clams Mya and Macoma. Long-
term bioassays with Pacific and Kumamoto
oysters, carried out at Oregon State University
using calcium-base SWL (10 percent solids),
showed no adverse effects at 50 mg/1 after 266
days of exposure. Slightly deleterious effects were
noted at 100 mg/1, indicating maximum safe
limits lie between 50 to 100 mg/1. Continuing field
studies at Grays Harbor, Wash., support these
findings. In bioassays conducted in salt water by
the Washington State Department of Fisheries, sal-
mon exposed for 30 days to concentrations of ap-
proximately 500 mg/1 of 10-percent SWL showed
no apparent ill effects. Herring eggs, on the other
hand, were adversely affected at concentrations
greater than 96 mg/1.
The apparent tolerance level for salmon in salt
water using kraft wastes was found by the above
investigation to range from dilutions of 1:16 to
1:90 after 14 to 30 days of exposure. Growth
studies conducted at Oregon State University by
the National Council for Stream Improvement
using raw kraft wastes in fresh water showed no
adverse effects to salmonid fishes after 3 to 5
weeks exposure in dilutions of 1:100. English (in
press), in his field studies of the English sole in
Puget Sound, reports a sustained and thriving
fishery in an area affected by SWL. Recent work
by the Federal Water Pollution Control Adminis-
tration (USDI 1967a) in Puget Sound showed
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damage to oyster larvae and developing English
sole eggs at concentrations greater than 10 mg/1
of 10-percent SWL. According to this report,
oyster growth and market condition is adversely
affected and phytoplankton productivity is in-
hibited at SWL concentrations over 50 mg/1.
Determining the toxicity of complex wastes like
oil, refinery petrochemicals, and pulpmill wastes
presents a number of problems. For one thing,
they contain many known and, perhaps, equally
as many unknown toxic substances in small quan-
tities. The toxicological and other physical and
chemical characteristics can vary considerably dur-
ing any given day, in any given plant, due to
changes in processes, sources of supplies, and the
end product being produced. Considerable varia-
tion in effluent characteristics can occur even in a
1-day period. The resulting wastes from these in-
dustries contain upwards of several hundreds of
compounds representing a number of homologous
series of compounds from different organic groups.
This complexity is augmented by the treatment of
the wastes, as well as by the spectrum of products
manufactured from the complex starting material
used. The relative ability to react biochemically
and to exert an oxygen demand is characteristic of
organic materials of such primary significance.
Many groups or series of compounds indicated
to be present in such wastes have been shown to
be toxic in varying degrees to aquatic life. It is
extremely difficult at this time, however, to place a
concentration limit or set threshold criteria for
such complex systems and hence should be indi-
vidually bioassayed and their discharge managed
accordingly.
Waterfront and boating activities.—Increasing
activities by commercial, military, and recreational
vessel operators raise the specter of introduction of
toxic materials in quantities sufficient to affect
marine organisms adversely. This is particularly
likely in the case of confined waters of small tidal
tributaries, lagoons, embayments, and other ma-
rine areas employed as harbors.
Toxic materials are used to prevent activities of
boring and fouling marine organisms. Usually,
however, every effort is bent in the case of toxic
coatings to prevent rapid release of toxic materials
into the environment since rapid loss reduces ef-
fectiveness of such coatings and increases costs.
Some leaching is unavoidable—even necessary.
Thus, the presence in confined harbors of many
vessels whose bottoms are coated with toxic mate-
rials already presents hazards in some places. This
would be especially true after spring "fitting out"
for small boats.
Boatowners, boat and boatyard operators, fish-
ing and commercial pier and marina operators are
not especially noted for the care extended to
nearby waters. Commonly, everything that can be
is flushed or jettisoned into the water. Purposeful
discharges are many—though perhaps decreasing
as emphasis on water pollution has increased.
Paint leaching, paint spillage, oil and gasoline
spillage, detergents, wood preservatives, ex-
hausted containers, metallic objects of all types
(zinc, copper, brass, iron, etc.), and other jetsam
contribute to contamination from these sources.
Except for confined areas where there are many
of these operations such as large shipyards, major
military and commercial anchorages, and large
and small boat anchorages, it is doubtful that tox-
icity from these operations is of serious proportions
in tidal waters at this point. As with other fouling
or contaminating activities of society, however,
efforts should be made to keep biological damage
from these sources to a minimum. Some discharges
are controllable and should fall under the same
rules as industrial or community discharges. In the
case of large marinas, shipyards, or major anchor-
ages, requirements suggested elsewhere may have
to be applied. Future research should include spe-
cific attention to this aspect.
Similar comments can be made about water-
front structures and port operations. There is con-
siderable use of toxic materials in preservation of
wood, steel, and masonry structures used on ma-
rine waterfronts. Discharge of toxic materials,
surfactants, petroleum products, other materials
and jetsam is common. Similar recommendations
can be made for control and research as those for
boat, boatyard, and vessel operations.
Disposal of laboratory wastes.—The rapid
growth of marine sciences during the past decade
is reflected in an ever-increasing number of sta-
tions and laboratories engaged in the study of
various aspects of oceanography. These institu-
tions are located along the entire coastline of the
United States: 28 on the Atlantic, 12 on the Gulf,
and 29 on the Pacific. About 2,500 persons (in-
vestigators, students, technicians, and laboratory
assistants) are employed in these 66 establish-
ments (Hiatt, 1963).
The above number includes institutions operated
by Federal and State governments, by universities
or privately endowed concerns which receive their
main support from the government and national
foundations. Other laboratories, hospitals, and re-
search institutions operated by industrial concerns
for their specific needs are not included in this
total. The laboratories range from small establish-
ments, with less than four investigators, to very
large institutions employing or providing research
space for 200 to 500 investigators.
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The types of research cover various fields of
biology, microbiology, experimental physiology,
biochemistry, chemistry, biophysics, molecular
biology, radiobiology, fishery biology, fishery man-
agement, and industrial research. Consequently,
the effluents discharged into estuarine and coastal
waters vary from ordinary household sewage to
mixtures containing an array of organic and inor-
ganic compounds, drugs, and radioactive isotopes.
The composition of these effluents cannot be pre-
dicted with certainty because the type of research
varies greatly from year to year. The laboratory
effluent is separated usually from the sea water
system, which as a rule has independent plumbing,
but is mixed with the domestic sewage and fre-
quently is discharged into natural waters. When
many scientific establishments are concentrated in
a relatively small area, the situation may become
serious. Chlorinated raw sewage entering the
harbor a short distance from shore may be caught
by a tidal eddy and for several hours circulate
close to the sea water intakes of several labora-
tories before it is carried out by tides.
To maintain desired water quality requirements
for aquatic life, it is necessary to separate labora-
tory effluents from domestic sewage and provide
treatment that renders them harmless to aquatic
biota. Under no conditions should highly toxic
chemical compounds or drugs be permitted to be
discharged into natural waters if toxic concentra-
tions of them can be detected by chemical and
physical methods.
Many marine laboratories are utilizing exotic
and endemic microorganisms, some pathogenic,
in research. Extreme caution must be exercised to
prevent contamination of water by introduction
of biological materials which can harm marine
organisms.
Laboratory administrators should be responsible
for the periodical examination of the toxicity of
the effluent discharged into natural waters by their
institutions.
Recommendation: (1) Allowable concentrations of
metals, ammonia, cyanides, and sulfides should be
determined by the use of 96-hour TLm values and
appropriate application factors. Preferably, the TLm
values should be determined by flow-through bioassays
in which environmental factors are maintained at levels
under which these materials are most toxic. Tests
should utilize the most sensitive life stage of species of
ecological or economic importance in the area. Tenta-
tively, it is suggested that application factors should
be Hoo for pesticides and metals, !/6o for ammonia,
%o for cyanide, and %o for sulfides.
(2) There is evidence that fluorides are accumula-
tive in organisms. It is tentatively suggested that
allowable levels should not exceed those for drinking
water.
(3) The further dilution of wastes in marine waters
suggests that the adoption of criteria established for
detergents and surfactants in fresh water also will
protect adequately biota in the marine environment.
(4) Bacteriological criteria of estuarine waters
ultilized for shellfish cultivation and harvesting should
conform with the standards as described in the Na-
tional Shellfish Sanitation Program Manual of Opera-
tion. These standards provide that:
(a) Examinations shall be conducted in accord-
ance with the American Public Health Association
recommended procedures for the examination of
sea water and shellfish.
(b) There shall be no direct discharges of un-
treated sewage.
(c) Samples of water for bacteriological examina-
tion to be collected under those conditions of time
and tide which produce maximum concentration of
bacteria.
(d) The coliform median MPN of the water does
not exceed 70/100 ml, and not more than 10 percent
of the samples ordinarily exceed an MPN of 230/
100 ml for a 5-tube decimal dilution test (or 330/
100 ml where the 3-tube decimal dilution test is
used) in those portions of the area most probably
exposed to fecal contamination during the most un-
favorable hydrographic and pollution conditions.
(e) The reliability of nearby waste treatment
plants shall be considered in the approval of areas
for direct harvesting.
(5) It is also essential to monitor continuously waste
from tar, gas, and coke, petroleum refinery, petrochemi-
cal, and pulp and paper mill operations. They all
produce complex wastes of great variability, not only
from facility to facility, but also from day to day.
This should be done on an individual basis with bio-
assays. These tests should be made at frequent inter-
vals to determine TLm values as described for other
wastes. For the more persistant toxicants, an applica-
tion factor of Moo should be used while for unstable or
biodegradable materials an application of %o is tenta-
tively suggested.
(6) Concentration of other materials with noncumu-
lative toxic effects should not exceed Vio of the 96-hour
TLm value. For toxicants with cumulative effects, the
concentrations should not exceed %o and Hoo for the
above respective values.
When two or more toxic materials that have additive
effects are present at the same time in the receiving
water, some reduction in the permissible concentrations
as derived from bioassays on individual substances is
necessary. The amount of reduction required is a func-
tion of both the number of toxic materials present and
their concentrations with- respect to the derived per-
missible concentration. An appropriate means of assur-
ing that the combined amounts of the several substances
do not exceed a permissible combination for the mix-
ture is through the use of following relationship:
(r+r---+r*
\ La Lb Li,
Where C,, G> . . . G, are the measured concentra-
tions of the several toxic materials in the water and
L», Lb . . . Ln are the respective permissible concen-
trations (limits) derived for the materials on an in-
dividual basis. Should the sum of the several fractions
exceed one, then a local restriction on the concentra-
tion of one or more of the substances is necessary.
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wildlife
WILDLIFE require water of a quality ade-
quate to maintain their health, as well as
optimum production of beneficial biota in their
environment. A healthy animal is one that can
survive to an average lifespan, display normal be-
havior and migration patterns, and reproduce suc-
cessfully. We are fully as concerned with the
impact of pollution on the wildlife habitat as we
are with the direct or indirect effects on the vari-
ous species of wildlife. Optimum production of
beneficial biota in the multifarious wildlife habitats
implies maintenance of natural, balanced ecosys-
tems unaltered by pollution.
Wildlife is defined herein as all species of mam-
mals, birds, reptiles, and amphibians. Because of
the dependence of waterfowl on aquatic habitats,
their needs form the primary basis for definition
of water quality requirements for wildlife. In most
instances, water quality satisfactory for waterfowl
and their habitat would be satisfactory for most
other wildlife species. It is axiomatic that water
quality that can be tolerated by, and is productive
of, fish and their food organisms is generally ade-
quate for waterfowl and their habitat. Indeed, fish
and many of the organisms upon which they feed
are also important in the diet of many species of
wildlife; e.g., pelicans, loons, mergansers, other
ducks, herons, otters, bears, raccoons, snakes, alli-
gators, etc. It is obvious that requirements for sur-
vival of fish and aquatic organisms also constitute
the same requirements for preservation of the wild-
life habitat. Because of the greater sensitivity of
fish and their food organisms to pollution, much
more intensive research has been required and
conducted with those forms than with wildlife.
The water quality requirements stipulated for
fish and aquatic organisms generally are acceptable
for wildlife in regard to the following environ-
mental factors and materials: dissolved oxygen,
temperature, pH, carbon dioxide, alkalinity, hard-
ness, salinity, sulfides, ammonia, nutrients, floating
materials, surface active agents, tainting materials,
radionuclides, heavy metals, pesticides, and other
chemicals. Certain of these factors including DO,
pH, alkalinity, salinity, light, settleable solids, oil,
and nuisance growths must be considered in their
special relations to wildlife and waterfowl and
their habitats. These are discussed separately.
Dissolved oxygen
In waterfowl habitats, in addition to DO re-
quirements for the open water, there is need to
keep the bottom aerobic for the suppression of
botulinus organisms. Botulism, caused by Clos-
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tridium botulinum, has killed millions of water
birds. Jensen and Williams (1964) state "When
conditions are favorable—suitable temperature,
an organic medium to satisfy food requirements,
and an absence of atmospheric oxygen (the orga-
nism is a strict anaerobe)—the spores germinate
and multiply." Although the exact qualities of the
water favoring its production cannot always be
categorized, anaerobic conditions in shallow, fringe
areas of ponds or reservoirs often are indicted as
contributory to botulism outbreaks. Maintenance
of adequate water circulation in all parts of these
shallow reservoirs might deter production of the
toxic bacteria. Also, accumulation of organic
wastes from mills and other sources should be
prevented in aquatic habitats, particularly where
botulism has been a problem.
PH
The chapter in Water jowl Tomorrow, by Mc-
Callum (1964), entitled "Clean Water, and
Enough of It," summarizes many of the water pol-
lution problems of aquatic habitats. McCallum
states "Acid mine water has destroyed or seriously
damaged the waterfowl value of more than 4,000
miles of streams in the United States. Working as
well as abandoned coal mines discharge an esti-
mated 3.5 million tons or more of acid each year
into streams, most of them east of the Mississippi
River." Martin and Uhler (1939) point to the fact
that "acidity may affect the growth of plants by
checking the work of nitrifying bacteria and
thereby preventing the normal decay of humus, or
by increasing the accumulation of carbon dioxide
and accompanying toxic organic substances."
In bioassays with aquatic plants, Sincock
(1966) found that when the pH of the water in
some test vessels dropped to 4.5, readhead-grass
(Potamogeton perfoliatus), a valuable waterfowl
food plant, died within a few days. Similarly, in
Back Bay, Va., between August and November,
1963, the aquatic plant production in pounds per
acre declined from 164 to 13; this atypical decline
was immediately preceded by an atypical decline
in pH to 6 5 compared to previous midsummer
readings of 7.7 to 8.5.
Generally, the submerged aquatic plants of
greatest value as waterfowl foods thrive best in
waters with a summer pH range of 7.0 to 9.2.
Alkalinity
bicarbonate alkalinity. Few waters with less than
25 mg/1 bicarbonate alkalinity can be classed
among the better waterfowl habitats. Many water-
fowl habitats productive of valuable waterfowl
foods, such as sago pondweed (Potamogeton
pectinatus), widgeongrass (Ruppia maritima and
R. occidentalism, banana waterlily (Castalia
flava), wild celery (Vallisneria americana) and
others, have a bicarbonate alkalinity range of 35
to 200 mg/1.
Definitive, submerged aquatic plant communi-
ties develop in waters with different concentrations
of bicarbonate alkalinity. It is logical to presume
that excessive and prolonged fluctuation in alkalin-
ity would not be conducive to stabilization of any
one plant community type. There is not sufficient
experimental evidence available to define the ef-
fects of various degrees and rates of change in
alkalinity on aquatic plant communities. Fluctua-
tions of 50 mg/1 probably would contribute to
unstable plant communities. Fluctuations of this
magnitude are quite possible due to canals con-
necting watersheds, diversion of irrigation water,
flood diversion canals, etc.
Salinity
Generally, waters with reasonably high bicar-
bonate alkalinity are more productive of valuable
waterfowl food plants than are waters with low
Salinity may have a twofold effect on wildlife: a
direct one affecting the body processes of the spe-
cies involved and an indirect one altering the en-
vironment, making living and species perpetuation
difficult or impossible.
Direct Effect of Salinity
A review of the available literature produced
very little information on possible effects of salinity
upon game mammals. There was a single reference
made in which a 0.9-percent solution of sodium
chloride was listed as innocuous to mammals
(Selye, 1943).
As evidenced by the literature, salinity has a
very detrimental effect on all of the domestic
species of the order Galliformes (chickens and
turkeys). A solution of 0.9-percent sodium chlo-
ride used by Barred Rock chickens for drinking
purposes was extremely toxic, causing numerous
deaths (Krista, et al., 1961). The birds exhibited
water retention in the body and marked renal
changes. While working with turkey poults, it was
found that a 0.5-percent sodium chloride solution
was fatal to 50 percent of the individuals tested
and in addition that various sodium compounds
(sodiunTcitrate, sodium carbonate) in 0.75- per-
cent solutions also were very toxic (Scrivner,
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1946). There was a significant drop in egg produc-
tion by white leghorn chickens that drank a 1.0-
percent salt solution and a 0.7-percent salt solution
used for drinking water caused a significant mor-
tality in day-old chicks. It is reported that a 0.52-
percent salt solution used for drinking water
retarded growth in domestic chickens (Rosenberg
and Sess, 1954). Using a 0.35-percent salt solu-
tion for drinking water increased mortality of baby
chicks, however, water containing 0.30, 0.26, and
0.25 percent salt was nontoxic (Doll, et al., 1946).
Correlation of this toxicity to avian game was
indicated when a group of ornamental pheasants
(order Galliformes) and chickens were salt poi-
soned; all the pheasants succumbed, but only a
few of the chickens (Field and Evans, 1946).
Young ducklings were killed or retarded in growth
as a result of salt poisoning by solutions equal to
those found on the Suisun Marsh, Calif., during
the summer months (Suisun Marsh is formed by
the combined deltas of several rivers; i.e., Sacra-
mento, San Joaquin, and the Middle River. Grif-
fith, 1963). Salinity maxima during July (1956 to
1960) varied from 0.55 to 1.74 percent; the
means varied from 0.07 to 1.26 percent. During
3 of these years the mean salinity level exceeded
levels reported as causing mortality in domestic
chickens. Adult quail preferred dehydration to
drinking water having a salt concentration that
would be fatal to juvenile chickens and detrimental
to egg production (Bartholemew and MacMillan,
1961).
These conditions must be kept in mind because
there is a potential hazard of a sodium compound
buildup in the Lower Colorado River area to levels
that would be toxic to avian game.
Indirect Effects of Salinity
Indirect effects of salinity on wildlife would gen-
erally be restricted to that action imposed upon the
vegetative growth along the river. Modification of
a segment of the associated vegetation can result
in a complete change in the environment. The
game animals affected by a modification of sub-
mergent and emergent vegetation would be mainly
the various species of waterfowl.
Different habitats, of use to a great variety of
wildlife, develop under different concentrations of
salinity. In coastal areas, where the salinity gen-
erally represents various dilutions of sea water, the
habitats can be categorized as fresh to slightly
brackish (0 to 3.5%0), moderately brackish (3.5
to 13.5%0), and strongly brackish to marine
(13.5 to 35.0%o). Valuable submerged aquatic
plants occurring in the first category are bushy
pondweed, Najas quadalupensis, northern naiad,
Najas ftexilis, several pondweeds, Potamogeton
spp., wild celery, Vallisneria americana, and
watershield, Brasenia schreber.
In moderately brackish waters, some of the
better waterfowl foods are sago pondweed, Pota-
mogeton pectinatus, muskgrasses, Cham spp,
horned pondweed, Zanichellia palustris, and a few
pondweeds, Potamogeton spp., that thrive in both
fresh waters and moderately brackish waters.
Important food plants for waterfowl in the most
saline waters are widgeongrass, Ruppia maritima,
shoalgrass, Diplanthera wrighti, spiny naiad, Najas
marina, and eelgrass, Zostera manna.
Probably the most important consideration, in
regard solely to salinity and the plant communities
which develop, is the degree of fluctuation. Ob-
servations and bioassays by Bourn (1932), Martin
and Uhler (1939), Sincock (unpublished data),
and others have demonstrated the destructive ef-
fects of rapid fluctuations in salinity on aquatic
plants. Plasmolysis of the tender leaves and stems,
induced by changes in osmotic presure of the
varied water salinities, results in death of the
plants.
Based on empirical knowledge, it is believed
that salinity fluctuations in a 24-hour period could
be 1, 2, and 4r/,, in each of the three respective
salinity classes without causing harm to most of
the aquatic plants.
Emergent marsh plants also have varying toler-
ances to water salinity; generally, they are not as
sensitive to minor changes as are the submerged
aquatic plants. Fresh water marshes are normally
much more productive of wildlife food plants than
strongly saline marshes.
The reaction of vegetation associated with
waterfowl marshes to salinity has become an im-
portant consideration in the management of those
marshes. Salinity of 6%0 and above is detrimental
to many prime, submergent waterfowl food plants
(Tester, 1963). Controlled salinity levels, how-
ever, have become a valuable tool in marsh man-
agement. Undesirable marsh plants can be con-
trolled or eliminated and desirable plants encour-
aged by manipulation of salinity levels (California
Department of Fish and Game, 1963). For ex-
ample, the seeds of cattail (an undesirable plant)
will not germinate in a solution having 7 mmhos
conductivity while alkali bulrush (desirable plant)
will germinate in solutions of up to 9 mmhos con-
ductivity (Kauship, 1963). Therefore, raising
salinity levels to 8 mmhos conductivity would
eliminate cattail, but allow alkali bulrush to
flourish.
The germination of seeds and the growth of
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seedlings are critical stages in the plant-salinity
relationship; plants become more tolerant to salin-
ity with age. Adult plants of cattail, hard-stem
bulrush, and alkali bulrush can withstand saline
solutions of 10, 15, and 18 mmhos conductivity,
respectively.
There is an increasing amount of cultivation of
agricultural crops for waterfowl feeding purposes
(barley and Bermuda pasture grass) on waterfowl
management areas along the lower Colorado River
(Land, personal communication). An increasing
level of salinity in the river, if the crops are irri-
gated with river water, may have a detrimental
effect upon this practice. It has been stated that
alkali bulrush grows in soil having salinity levels
well above the survival range of agricultural crops
(Nelson, 1953). Therefore, though natural marsh
growth along the lower Colorado River should not
be affected by an increase in salinity, artificially
developed waterfowl feeding areas on wildlife
management areas may be detrimentally affected.
Factors Associated with Increased Salinity
There are three other aspects of water quality
that are normally associated with irrigation return
water. They are toxic residues, turbidity, and high
temperature.
These waters may contain toxic residues of
insecticides and herbicides used as a part of agri-
cultural practices, which may affect avian game
species (Rudd and Genelly, 1956). Turbidity has
a very definite effect on submerged aquatic plants,
limiting growth or even eliminating all submergent
vegetation. Another characteristic of irrigation
return water is high temperature. A rise in tem-
perature causes an amplification of the effects of
salinity upon vegetative growth (Ani and Powers,
1938).
Assessment of any of these possible sources of
wildlife damage would necessitate thorough ex-
amination of existing conditions for correlation to
projected conditions.
Light penetration
Algae, turbidity from silts and clays, and color
of the water all affect one environmental factor of
major importance in the productivity of aquatic
wildlife habitat—light penetration of the water.
The results of many of man's activities, including
agriculture, industry, navigation, channelization,
dredging, land modification, and eutrophication
from sewage or fertilizers, often reduce light trans-
mission to the degree that aquatic angiosperms of
value to wildlife cannot grow.
Bioassays and field studies by Bourn (1932)
and Sincock (unpublished data) demonstrated
that at least 5 percent of the total incident light at
the surface was required for growth of several
aquatic plants (as measured while the sun was
near its apex, between 10 a.m. and 2 p.m.). Opti-
mum production occurred where 10 to 15 percent
of the light reached the bottom. Most aquatic
plants will grow in water depths of 6 feet or more
if sufficient light is available. For optimum growth
in aquatic wildlife habitats the light at the 6-foot
depth should be 10 percent of incident light at the
surface; tolerable limits would be 5 percent of the
light at the surface to the same depth. In situ deter-
minations of light penetration, as measured with a
subsurface photometer, provide the best indication
of suitability for plant growth.
Observations have indicated that prolonged ex-
clusion of adequate light results in the destruction
of submerged aquatic plants; the period during
which the plants must endure less than 5 percent
of the incident light at the surface should probably
not exceed 7 consecutive days if they are to
survive.
Of course, light penetration and the factors
affecting it; e.g., turbidity, color, and algal con-
centrations, vary in intensity daily, seasonally, and
annually. In most areas, the submerged aquatic
plants die back in the fall and winter and the
quantity of light required becomes less critical as
a requirement. In the spring and summer, how-
ever, sufficient light is imperative to growth.
Settleable substances
Accumulation of silt deposits is destructive to
aquatic plants, not only by the associated turbidity,
but by the creation of a soft, semiliquid sub-
stratum inadequate for anchoring the roots. Back
Bay, Va., and Currituck Sound, N.C., serve as
examples of the destructive nature of silt deposi-
tion. Approximately 40 square miles of bottom are
covered with soft, semiliquid silts up to 5 inches
deep; these areas, constituting one-fifth of the total
area, produce only 1 percent of the total aquatic
plant production.
Waterbirds, muskrats, otters, and many other
wildlife species require water that is free of surface
oil. Studies by Hartung (1965) demonstrated that
egg laying was inhibited when mallards ingested
small quantities of oil. When oil from the plumage
was coated on mallard eggs, it reduced hatching
from 80 to 21 percent. The full significance of this
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type of damage to wildlife populations is unknown.
Dramatic losses of waterbirds (ducks, geese,
coot, swans, gannets, murres, and others) result
from contamination of the plumage by oil from the
surface of the water. Once the bird's plumage is
soaked with oil, the bird loses its natural insula-
tion to the cold and dies. Many hundreds of thou-
sands of birds have died from oil pollution in
some years in North American waters.
Oil that settles to the bottom of aquatic habitats
can blanket large areas and destroy the plants and
animals of value to waterfowl. Reportedly, some
oil sludges on the bottoms of aquatic habitats tend
to concentrate pesticides, thus creating a double
hazard to waterfowl that would pick up these con-
taminants in their normal feeding process.
Pesticides
No pesticides should occur in water to the
degree that they affect the health, reproduction,
and natural growth of wildlife. Although tolerable
limits of pesticides for fish and aquatic inverte-
brates presently serves as the best guideline to
limits that might not cause excessive harm to wild-
life, we must call attention to the paucity of our
knowledge on the significance of biological mag-
nification. Keith (1966) and Hickey, Keith, and
Coon (1966) reported 14 /*§/! of DDT and its
metabolites in lake bottom muds. About 50 times
that quantity was reported in amphipods (Ponto-
poreia affinis), 500 times as much in fish and old
squaw ducks, and 15,000 times as much in herring
gulls that ate the fish. Reproduction of the gulls
decreased.
DDT residues in wildlife are cosmopolitan, oc-
curring even in penguins from the Antarctic. Con-
centration of insecticides in the flesh of edible wild
animals poses a potential hazard to man's well
being. Recently, the hunting season for pheasants
in California was closed for a while because of
concern about secondary poisoning to man.
In our infinite ignorance of the dynamics of
biological magnification in wildlife habitats, toler-
able limits for pesticides in water cannot be real-
istically established.
Seldom do we observe mass mortality of wildlife
from pesticide application, but occasionally iso-
lated examples occur. Sincock (personal com-
munication) observed an aerial spraying operation
of 2 pounds of toxaphene and 1 pound of DDT
per acre for armyworm control on soybeans in
Virginia in September 1960; 2 days later he was
called to determine the cause of death of several
geese and ducks penned in the area. Dead fish in
adjacent canals also confirmed the presumptive
diagnosis of death from pesticidal poisoning.
Nuisance and toxic growths
Algae present several problems to wildlife and
their habitat. Excessive blooms can reduce light
penetration, as already mentioned; Nostoc spp.
and other colonial algae often attach to higher
aquatic plants and virtually weigh them to the
bottom, causing their destruction. Cladophora sp.
growths in Great South Bay, Long Island, have
become a major problem as a result of fertilization
by sewage effluents and wastes from duck farms.
Although problems with sewage disposal occur
throughout the Nation, some of the most severe
occur in small, coastal resort areas that must ac-
commodate a massive influx of tourists during the
warm, summer season, along with the skyrocketing
use of boats with toilet facilities.
Sincock, Inglis, and Irby (unpublished data)
contacted most agencies concerned with pollution
and conservation problems along the Atlantic and
Gulf Coast in August 1966. Many examples of
sewage pollution were found. One large southern
city dumped 15 million gallons of untreated
sewage each day into its harbor. Another mid-
Atlantic city had major problems with odors
caused by the disintegration of sea lettuce (Ulva
lactuca) that thrived upon sewage effluent in the
harbor.
Several of our national wildlife refuges are,
unfortunately, downstream from the inflow of
treated and untreated sewage. The problems in-
clude offensive odors, sterility of the entire aquatic
biota, excessive algal blooms that exclude light,
and toxic algae. Some algae, e.g., sea lettuce, re-
portedly taint the flesh of brant and other water-
fowl that consume it.
Several of the blue-green algae are toxic. Olson
(1964) states, "When a toxic strain becomes
predominant in a water bloom, hundreds of birds
may die in a few hours. Then any living creature
that drinks the water is a potential victim, and
shorelines may be strewn with bodies of mammals,
land birds, and waterfowl." Gorham (1964),
discussing livestock and wildlife poisoning from
his notable research on algae poisoning, states
"Five species have been most implicated in such
poisonings: Microcystis aeruginosa (including
Mic. toxica), Anabaena flos-aquae (including An.
lemmermannii), Aphanizomenon flos-aquae,
Gloetrichia echinulata, and Coelospaerium kutz-
ingeanum." In controlled tests, Olson (1964)
97
-------
found that time of death was generally related to
the size of the dose. Four teaspoonfuls of an un-
concentrated suspension of Anabaena lemmer-
manni killed a great blue heron in 14 minutes.
Olson further states "Extensive algae blooms are
potentially dangerous to waterfowl, especially
where the principal component is Anabaena flos-
aquae or Anabaena lemmermanni, . . . To fore-
stall wildfowl losses, it would be desirable to keep
surface waters free of heavy algae growths".
Lead poisoning
The most demonstrative cause of waterfowl
mortality from pollution is lead poisoning. Twelve
million pounds of lead shot are expended annually
over the Nation's best waterfowl habitats. The
shot remains there relatively unchanged. Water-
fowl frequently ingest these shot and die. Annual
mortality is estimated at roughly 1 million birds.
The major ammunition companies and several
conservation organizations currently are conduct-
ing research to develop a relatively nontoxic shot;
this endeavor should be continued until a satis-
factory solution is discovered and this annual
source of pollution is stopped. A change in shot-
type and adjustment of industry to its production
and use would seem possible in 4 years.
Disease
An understanding of the ecological relationships
of wildlife disease, water pollution, and water
quality characteristics is yet to be obtained.
Botulism, fowl cholera, and aspergillosis all can
affect birds in aquatic habitats. Although certain
conditions of temperature, alkalinity, organic mat-
ter, and other factors in the environment are
suspect as contributing to disease outbreaks no
exact parameters can be defined. Offal from poul-
try houses, dumped directly into estuaries in
Maine, was suspected of causing recent wildlife
losses from fowl cholera.
no species become extinct because of water pollu-
tion.
The bald eagle, the symbol of the United States,
has declined drastically in parts of the United
States. Studies are underway to determine the
cause. Although pesticides are largely suspect, it
has been suggested that lead poisoning, due to
eating ducks that died from crippling or lead
poisoning, might be involved.
Water quality requirements for endangered
species of fish and wildlife should receive State and
Federal review on all applicable interstate waters
and be of the highest quality obtainable.
Recommendation: To preserve suitable waterfowl
food plants, salinity fluctuations in a 24-hour period
should not exceed 1 %„ in fresh to slightly brackish water
(0 to 3.5%0); 2%, in moderately brackish water (3.5 to
13.5#»); and 4
-------
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appendix
106
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Glossary of Commonly Used Biological and Related Terms in Water and Waste Water Control*
ACCLIMATION—The process of adjusting to a change in
an environment.
ADAPTATION—A change in the structure, form, or habit
of an organism resulting from a change in its environ-
ment.
AEROBIC ORGANISM—An organism that thrives in the
presence of oxygen.
ALGAE (Alga)—Simple plants, many microscopic, con-
taining chlorophyll. Most algae are aquatic and may
produce a nuisance when conditions are suitable for
prolific growth.
ALGICIDE—A specific chemical highly toxic to algae.
Algicides are often applied to water to control nuisance
algal blooms.
ALGOLOGY—The study of algae.
AMPHIPODS—(see Scuds).
ANADROMOUS FISHES—Fishes that spend a part of their
life in the sea or lakes, but ascend rivers at more or
less regular intervals to spawn. Examples are sturgeon,
shad, salmon, trout, and striped bass.
ANAEROBIC ORGANISM—An organism that thrives in the
absence of oxygen.
ANNELIDS—Segmented worms, as distinguished from the
nonsegmented roundworms and flatworms. Most are
marine; however, many live in soil or fresh water.
Aquatic forms may establish dense populations in the
presence of rich organic deposits. Common examples
of segmented worms are earthworms, sludgeworms,
and leeches.
ASSIMILATION—The transformation of absorbed nutri-
ents into body substances.
AUTOTROPHIC ORGANISM—An organism capable of con-
structing organic matter from inorganic substances.
BENTHIC REGION—The bottom of a body of water. This
region supports the benthos, a type of life that not
only lives upon but contributes to the character of the
bottom.
BENTHOS—Aquatic bottom-dwelling organisms. These in-
clude: (1) Sessile animals, such as the sponges, barna-
cles, mussels, oysters, some of the worms, and many
attached algae; (2) creeping forms, such as insects,
snails, and certain clams; and (3) burrowing forms,
which include most clams and worms.
BIOASSAY—A determination of the concentration of a
given material by comparison with a standard prepara-
tion; or the determination of the quantity necessary to
affect a test animal under stated laboratory condi-
tions.
BIOMASS—The weight of all life in a specified unit of
environment or an expression of the total mass or
weight of a given population, both plant and animal.
BIOTA—All living organisms of a region.
BIVALVE—An animal with a hinged two-valve shell; ex-
amples are the clam and oyster.
BLOOM—A readily visible concentrated growth or ag-
gregation of plankton (plant and animal).
BLUE-GREEN ALGAE—A group of algae with a blue pig-
ment, in addition to the green chlorophyll. A stench
is often associated with the decomposition of dense
blooms of blue-green algae in fertile lakes.
CATADROMOUS FISHES—Fishes that feed and grow in
fresh water, but return to the sea to spawn. The
best known example is the American eel.
CLEAN WATER ASSOCIATION—An association of orga-
nisms, usually characterized by many different kinds
(species). These associations occur in natural unpol-
luted environments. Because of competition, predation,
etc., however, relatively few individuals represent any
particular species.
COARSE OR ROUGH FISH—Those species of fish considered
to be of poor fighting quality when taken on tackle
and of poor food quality. These fish may be undesir-
able in a given situation, but at times may be classified
differently, depending upon their usefulness. Examples
include carp, goldfish, gar, sucker, bowfin, gizzard shad,
goldeneye, mooneye, and certain kinds of catfish.
COELENTERATE—A group of aquatic animals that have
gelatinous bodies, tentacles, and stinging cells. These
animals occur in great variety and abundance in the
sea and are represented in fresh water by a few types.
Examples are hydra, corrals, sea anemones, and jelly-
fish.
COLD-BLOODED ANIMALS (Poikilothermic Animals) —
Animals that lack a temperature regulating mecha-
nism that offsets external temperature changes. Their
temperature fluctuates to a large degree with that of
their environment. Examples are fish, shellfish, and
aquatic insects.
CONSUMERS—Organisms that consume solid particles of
organic food material. Protozoa are consumers.
CRUSTACEA—Mostly aquatic animals with rigid outer
coverings, jointed appendages, and gills. Examples are
crayfish, crabs, barnacles, water fleas, and sow bugs.
DAPHNIA (see Water Fleas).
DERMATITIS—Any inflammation of the skin. One type
may be caused by the penetration beneath the skin of
a cercaria found in water; this form of dermatitis is
commonly called "swimmers' itch."
DYSTROPHIC LAKES—Brown-water lakes with a very low
lime content and a very high humus content. These
lakes often lack nutrients.
ECOLOGY—The science of the interrelations between liv-
ing organisms and their environment.
EMERGENT AQUATIC PLANTS—Plants that are rooted at
the bottom but project above the water surface. Ex-
amples are cattails and bulrushes.
ENVIRONMENT—The sum of all external influences and
conditions affecting the life and the development of an
organism.
EPILIMNION—That region of a body of water that ex-
tends from the surface to the thermocline and does not
have a permanent temperature stratification.
ESTUARY—Commonly an arm of the sea at the lower end
of a river. Estuaries are often enclosed by land except
at channel entrance points.
EULITTORAL ZONE—The shore zone of a body of water
between the limits of water-level fluctuation.
EUPHOTIC ZONE—The lighted region that extends ver-
tically from the water surface to the level at which
Extracted from: Geckler, J. R., K. M. Mackenthun, and W. M. Ingram. 1963.
107
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photosynthesis fails to occur because of ineffective light
penetration.
EURYTOPIC ORGANISMS—Organisms with a wide range of
tolerance to a particular environmental factor. Ex-
amples are sludgeworms and bloodworms.
EUTROPHICATION—The intentional or unintentional en-
richment of water.
EUTROPHIC WATERS—Waters with a good supply of nu-
trients. These waters may support rich organic pro-
ductions, such as algal blooms.
FACULTATIVE AEROBE—An organism that although fun-
damentally an anaerobe can grow in the presence of
free oxygen.
FACULTATIVE ANAEROBE—An organism that although fun-
damentally an aerobe can grow in the absence of free
oxygen.
FALL OVERTURN—A physical phenomenon that may take
place in a body of water during the early autumn.
The sequence of events leading to fall overturn in-
clude: (1) Cooling of surface waters, (2) density
change in surface waters producing convection cur-
rents from top to bottom, (3) circulation of the total
water volume by wind action, and (4) vertical tem-
perature equality, 4 C. The overturn results in a uni-
formity of the physical and chemical properties of the
water.
FAUNA—The entire animal life of a region.
FLATWORMS (Platyhelminthes)— Nonsegmented worms,
flattened from top to bottom. In all but a few of the
flatworms, complete male and female reproductive sys-
tems are present in each individual. Most flatworms
are found in water, moist earth, or as parasites in
plants and animals.
FLOATING AQUATIC PLANTS—Plants that wholly or in
part float on the surface of the water. Examples are
water lilies, water shields, and duckweeds.
FLORA—The entire plant life of a region.
FRY (Sac Fry)—The stage in the life of a fish between
the hatching of the egg and the absorption of the
yolk sac. From this stage until they attain a length
of 1 inch, the young fish are considered advanced fry.
FUNGI (Fungus)—Simple or complex organisms without
chlorophyll. The simpler forms are one-celled; the
higher forms have branched filaments and complicated
life cycles. Examples of fungi are molds, yeasts, and
mushrooms.
FUNGICIDE—Substances or a mixture of substances in-
tended to prevent, destroy, or mitigate any fungi.
GAME FISH—Those species of fish considered to possess
sporting qualities on fishing tackle. These fish may
be classified as undesirable, depending upon their use-
fulness. Examples of fresh water game fish are sal-
mon, trout, grayling, black bass, muskellunge, walleye,
northern pike, and lake trout.
GREEN ALGAE—Algae that have pigments similar in color
to those of higher green plants. Common forms pro-
duce algal mats or floating "moss" in lakes.
HERBICIDE—Substances or a mixture of substances in-
tended to control or destroy any vegetation.
HERBIVORE—An organism that feeds on vegetation.
HETEROTROPHIC ORGANISM—Organisms that are depend-
ent on organic matter for food.
HIGHER AQUATIC PLANTS—Flowering aquatic plants.
(These are separately categorized herein as Emergent,
Floating, and Submerged Aquatic Plants.)
HOLOMICTIC LAKES—Lakes that are completely circu-
lated to the deepest parts at time of winter cooling.
HYPOLIMNION—The region of a body of water that ex-
tends from the thermocline to the bottom of the lake
and is removed from surface influence.
INSECTICIDE—Substances or a mixture of substances in-
tended to prevent, destroy, or repel insects.
INVERTEBRATES—Animals without backbones.
LDoo (see Median Lethal Dose).
LENITIC OR LENITIC ENVIRONMENT—Standing water and
its various intergrades. Examples of lenitic environ-
ments are lakes, ponds, and swamps.
LIFE CYCLE—The series of stages in the form and mode
of life of an organism: i.e., the stages between succes-
sive recurrences of a certain primary stage such as
the spore, fertilized egg, seed, or resting cell.
LIMNETIC ZONE—The open-water region of a lake. This
region supports plankton and fish as the principal plants
and animals.
LIMNOLOGY—The study of the physical, chemical, and
biological aspects of inland waters.
LITTORAL ZONE—The shoreward region of a body of
water.
LOTIC ENVIRONMENT—Running waters, such as streams
or rivers.
MACRO-ORGANISMS—Plants, animal, or fungal organisms
visible to the unaided eye.
MEDIAN LETHAL DOSE (LDM)—The dose lethal to 50
percent of a group of test organisms for a specified
period. The dose material may be ingested or in-
jected.
MEDIAN TOLERANCE LIMIT (TLm)—The concentration of
the tested material in a suitable diluent (experimental
water) at which just 50 percent of the test animals
are able to survive for a specified period of exposure.
MEROMICTIC LAKES—Lakes in which dissovled sub-
stances create a gradient of density differences in
depth, preventing complete mixing or circulation of
the water.
MICROORGANISM—Any minute organism invisible or
barely visible to the unaided eye.
MOLLUSCICIDE—Substances or a mixture of substances in-
tended to destroy or control snails. Copper is com-
monly used.
MOLLUSK (Mollusca)—A large animal group including
those forms popularly called shellfish (but not includ-
ing crustaceans). All have a soft unsegmented body
protected in most instances by a calcareous shell.
Examples are snails, mussels, clams, and oysters.
Moss—Any bryophytic plant characterized by small,
leafy, often tufted stems bearing sex organs at the
tips.
MOTILE—Exhibiting or capable of spontaneous move-
ment.
MYCOLOOY—The study of fungi.
NEKTON—Swimming organisms able to navigate at will.
NEMATODA—Unsegmented roundworms or threadworms.
Some are free living in soil, fresh water, and salt
water; some are found living in plant tissue; others live
in animal tissue as parasites.
NEUSTON—Organisms resting or swimming on the sur-
face film of the water.
OSMOLE—The standard unit for expressing osmotic pres-
sure. One osmole is the osmotic pressure exerted by
a one-molar solution of an ideal solute.
OCEANOGRAPHY—The study of the physical, chemical,
geological, and biological aspects of the sea.
OLIGOTROPHIC WATERS—Waters with a small supply of
nutrients; thus, they support little organic production.
ORGANIC DETRITUS—The paniculate remains of disin-
tegrated plants and animals.
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OXYGEN-DEBT—A phenomenon that occurs in an orga-
nism when available oxygen is inadequate to supply
the respiratory demand. During such a period the
metabolic processes result in the accumulation of
breakdown products that are not oxidized until suf-
ficient oxygen becomes available.
PARASITE—An organism that lives on or in a host or-
ganism from which it obtains nourishment at the ex-
pense of the latter during all or part of its existence.
PELAGIC ZONE—The free-water region of a sea. (Pelagic
refers to the sea, limnetic refers to bodies of fresh
water.)
PERIPHYTON—The association of aquatic organisms at-
tached or clinging to stems and leaves of rooted plants
or other surfaces projecting above the bottom.
PHOTOSYNTHESIS—The process by which simple sugars
and starches are produced from carbon dioxide and
water by living plant cells, with the aid of chlorophyll
and in the presence of light.
PHOTOTROPISM—Movement in response to a light gradi-
ent; for example, a movement towards light is positive
phototropism.
PHYTOPLANKTON—Plant plankton that live unattached
in water.
PISCICIDE—Substances or a mixture of substances in-
tended to destroy or control fish populations.
PLANKTON (Plankter)—Organisms of relatively small
size, mostly microscopic, that have either relatively
small powers of locomotion or that drift in that water
with waves, currents, and other water motion.
PLATYHELMENTHES (see Flatworms).
POIKILOTHERMIC ANIMALS (see Cold-Blooded Animals).
POOL ZONE—The deep-water area of .a stream, where
the velocity of current is reduced. The reduced veloc-
ity provides a favorable habitat for plankton. Silt
and other loose materials that settle to the bottom of
this zone are favorable for burrowing forms of benthos.
PORIFERA (see Sponges).
POTAMOLOOY—The study of the physical, chemical, geo-
logical, and biological aspects of rivers.
PRODUCERS—Organisms, for example, plants, that syn-
thesize their own organic substance from inorganic
substances.
PRODUCTION (Productivity)—A time-rate unit of the total
amount or organism grown.
PROFUNDAL ZONE—The deep and bottom-water area
beyond the depth of effective light penetration. All of
the lake floor beneath the hypolimnion.
PROTOZOA—Organism consisting either of a single cell
or of aggregates of cells, each of which performs all
the essential functions in life. They are mostly micro-
scopic in size and largely aquatic.
RAPIDS ZONE—The shallow-water area of a stream, where
velocity of current is great enough to keep the bottom
clear of silt and other loose materials, thus providing
a firm bottom. This zone is occupied largely by
specialized benthic or periphytic organisms that are
firmly attached to or cling to a firm substrate.
REDD—A type of fish-spawning area associated with run-
ning water and clean gravel. Fish moving upstream
sequentially dig a pocket, deposit and fertilize eggs,
and then cover the spawn with gravel from the next
upstream pocket. Fishes that utilize this type of spawn-
ing area include some trouts, salmons, and minnows.
RED TIDE—A visible red-to-orange coloration of an area
of the sea caused by the presence of a bloom of certain
"armored" flagellates.
REDUCERS—Organisms that digest food outside the cell
wall by means of enzymes secreted for this purpose.
Soluble food is then absorbed into the cell and re-
duced to a mineral condition. Examples are fungi,
bacteria, protozoa, and nonpigmented algae.
RHEOTROPISM—Movement in response to the stimulus
of a current gradient in water.
RIFFLE—A section of a stream in which the water is
usually shallower and the current of greater velocity
than in the connecting pools; a riffle is smaller than a
rapid and shallower than a chute.
ROTIFERS (Rotatoria)—Microscopic aquatic animals, pri-
marily free-living, fresh water forms that occur in a
variety of habitats. Approximately 75 percent of the
known species occur in the littoral zone of lakes and
ponds. The more dense populations are associated with
a substance of submerged aquatic vegetation. Most
forms ingest fine organic detritus for food, whereas
others are predaceous.
SCAVENGER—An organism that feeds upon decomposing
organic matter.
SCUDS (Amphipods)—Macroscopic aquatic crustaceans
that are laterally compressed. Most are marine and
estuarine. Dense populations are associated with
aquatic vegetation. Great numbers are consumed by
fish.
SECCHI Disc—A device used to measure visibility depths
in water. The upper surface of a circular metal plate,
20 centimeters in diameter, is divided into four quad-
rants and so painted that two quadrants directly op-
posite each other are black and the intervening ones
white. When suspended to various depths of water
by means of a graduated line, its point of disappearance
indicates the limit of visibility.
SEICHE—A form of perodic current system, described as
a standing wave, in which some stratum of the water
in a basin oscillates about one or more nodes.
SESSILE ORGANISMS—Organisms that sit directly on a
base without support, attached or merely resting unat-
tached on a substrate.
SHELLFISH POISON (Mussel Poison)—A poison present in
shellfish that have fed upon certain small marine
phytoplankters in which the toxic principles exist. The
shellfish concentrates the poison without harmful ef-
fects to itself, but man is poisoned through consump-
tion of the toxic flesh.
SPECIES (Both Singular and Plural)—A natural popula-
tion or group of populations that transmit specific
characteristics from parent to offspring. They are re-
productively isolated from other populations with
which they might breed. Populations usually exhibit a
loss of fertility when hybridizing.
SPHAEROTILUS—A slime-producing, nonmotile, sheathed,
filamentous, attached bacterium. Great masses are
often broken from their "holdfasts" by currents and
are carried floating downstream in gelatinous flocks.
SPONGES (Porifera)—One of the sessile animals that
fasten to piers, pilings, shells, rocks, etc. Most live
in the sea.
SPORE—The reproductive cell of a protozoan, fungus,
alga, or bryophyte. In bacteria, spores are specialized
resting cells.
SPRING OVERTURN—A physical phenomenon that may
take place in a body of water during the early spring.
The sequence of events leading to spring overturn in-
clude: (1) Melting of ice cover, (2) warming of sur-
face waters, (3) density change in surface waters pro-
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ducing convection currents from top to bottom, (4)
circulation of the total water volume by wind action,
and (5) vertical temperature equality, 4C. The over-
turn results in a uniformity of the physical and chemi-
cal properties of the water.
STANDING CROP—The biota present in an environment on
a selected date.
STENOTOPIC ORGANISMS—Organisms with a narrow range
of tolerance for a particular environmental factor. Ex-
amples are trout, stonefly nymphs, etc.
SUBLITTORAL ZONE—The part of the shore from the low-
est water level to the lower boundary of plant growth.
SUBMERGED AQUATIC PLANT—A plant that is continu-
ously submerged beneath the surface of the water.
Examples are the pondweed and coontail.
SWIMBLADDER—An internal, membranous, gas-filled or-
gan of many fishes. It may function as a hydrostatic
or sense organ, or as part of the respiratory system.
SWIMMERS' ITCH—A rash produced on bathers by a para-
sitic flatworm in the cercarial stage of its life cycle.
The organism is killed by the human body as soon
as it penetrates the skin; however, the rash may per-
sist for a period of about 2 weeks.
SYMBIOSIS—Two organisms of different species living
together, one or both of which may benefit and neither
is harmed.
SYSTEMATICS—The science of organism classification.
THERMOCLINE—That layer in a body of water where the
temperature difference is greatest per unit depth. It
is the layer in which the drop in temperature equals
or exceeds 1 C (1.8 F) per meter (39.37 inches).
TL,» (see Median Tolerance Limit).
TOLERANT ASSOCIATION—An association of organisms
capable of withstanding adverse conditions within the
habitat. It is usually characterized by a reduction in
species (from a clean water association) and an in-
crease in individuals representing a particular species.
TROPHOGENIC REGION—The superficial layer of a lake
in which organic production from mineral substances
takes place on the basis of light energy.
TROPHOLYTIC REGION—The deep layer of a lake, where
organic dissimilation predominates because of light
deficiency.
VERTEBRATE—Animals with backbones.
WARM AND COLD-WATER FISH—Warm-water fish include
black bass, sunfish, catfish, gar, and others; whereas
cold-water fish include salmon and trout, whitefish,
miller's thumb, and blackfish. The temperature factor
determining distribution is set by adaptation of the eggs
to warm or cold water.
WATERFLEAS (Daphnia)—Mostly microscopic swimming
crustaceans, often forming a major portion of the zoo-
plankton population. The second antennae are very
large and are used for swimming.
ZOOGLEA—Bacteria embedded in a jellylike matrix formed
as the result of metabolic activities.
ZOO-PLANKTON—Protozoa and other animal micoorga-
nisms living unattached in water. These include small
Crustacea, such as daphnia and cyclops.
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Section IV
agricultural uses
-------
introduction
ration for sale. Particularly critical is the use of
water in the production of market milk where
clean, bacteriologically safe water is mandatory.
In addition, the current time lag between milk
production on the farm and use in the home re-
quires the control of psychrophiles which adversely
affect milk quality.
The purity of water consumed by livestock has
far-reaching implications; polluted water can cause
death or disease of livestock and contaminate ani-
mal products. Many pollutants are important to
the livestock industry. Some understanding of the
tolerance level of these in water is important even
though animals also inevitably acquire organisms
and contaminants from soils or feeding and water-
ing locations. A dependable source of livestock
water of good quality is necessary for the profitable
production of animals.
Irrigation is the largest, single-purpose beneficial
consumptive use of water in agriculture. Water
quality criteria for irrigation become more critical
as fuller use is made of both available water and
irrigable land. Early irrigation developments were
largely on streams where only a small part of the
annual flow was used. Such streams contained
mainly dissolved solids resulting from the normal
leaching and weathering processes. Additional
uses concentrated the dissolved solids and intro-
duced other chemical and microbiological pol-
lutants that have become potentially hazardous to
crops, livestock, and to man.
Sources of water for agriculture
AMERICAN AGRICULTURE is both a
modern industry and a way of life. Not only
does water quality affect the safety and value of its
products, but also the health and welfare of farm-
ers and their families. Farmers do not usually have
access to the large, well-controlled water supply
and waste disposal systems of the great munici-
palities.
The Subcommittee on Water Quality for Agri-
cultural Uses is concerned with water used on indi-
vidual farmsteads, for livestock, and for irrigation
of crops.
For farmstead waters, particular attention is
given to the use of water by the human farm popu-
lation for drinking, food preparation, bathing, and
laundry. Other important uses include washing
and hydrocooling of fruits and vegetables in prepa-
Other than from precipitation, about three-
fourths of the water used in agriculture comes
from surface supplies and one-fourth from wells
and springs.
Man has been able to make better use of the
water by constructing dams, reservoirs, and dis-
tribution systems. During the period of greatest
need for irrigation and livestock, streamflows are
often minimal or even nonexistent. The highly
productive irrigated areas of the West have water
available because of the very large investment in
dams, reservoirs, and water channels.
Another large segment of land is irrigated by
pumping water from the ground. The total usable
underground water supply has been estimated to
be equivalent to 10-year's total rainfall or 35-year
runoff (172). Underground waters supply more
than 20 billion gallons of water a day for irrigation.
The States of California, Arizona, Texas, and New
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Mexico alone pump about 14 billion gallons a day
for this purpose. Pumping of ground water for sup-
plemental irrigation in the more humid portion of
the country has increased greatly in recent years.
Most of the water for individual farmstead use
comes from wells. Water from deep wells is more
apt to be free from pathogenic organisms than
that from springs, shallow wells, and surface
sources. Because on-farm treatment may be diffi-
cult, deep-well water is ordinarily desirable for
individual farmsteads unless dissolved solids are
excessive.
A dependable source of livestock water of good
quality is necessary for the profitable production
of animals.
Problems of agricultural water quality
Because the factories of agriculture are living
things, water quality affects not only the end prod-
uct, but also the efficiency of the production
machinery. Livestock, ill because of waterborne
disease or excess minerals, and irrigated crops
suffering from high salinity of irrigation water are
inefficient tools of production.
Agriculture, like any other industry or activity
of man, must deal with the quality-lowering impact
of all man's activities on water. Excessive quanti-
ties of silt from agricultural activities, road con-
struction, and urban development plague many of
our streams. Pollution from sewage, domestic and
industrial, continues to add each year to the water
quality problems of the farmer and urban dweller.
Upstream irrigation, reservoir evaporation, and
lowering or recycling of ground water impose in-
creasingly difficult problems for downstream irri-
gators because of increased salt concentrations.
Effects of water quality deterioration or the im-
pact of low-quality supplies on agriculture are
commonly insidious rather than dramatic. Even
relatively small-scale changes may result in large
economic consequences because of the sheer size
of the activity involved.
Excess salinity has been the instrument of de-
struction of profitable irrigation from the earliest
history of man. Besides the common ions, trace
elements in small concentrations, such as boron,
may be extremely harmful; and in many areas of
the world, pollution of water supplies by un-
treated or inadequately treated sewage in irrigation
results in widespread diffusion of enteric diseases.
While a great deal is known about the inhibiting
effects of salinity on plant growth, only very pre-
liminary assessments have been made of the eco-
nomic consequences in terms of the cost of reduc-
ing salinity. Thorne and Peterson (766) estimate
that approximately 1.35 billion acre feet of river
flow in the United States each year carries to the
sea between 250 and 330 million tons of salt. This
reflects a continuing geological process, which, in
total, man may not have changed greatly. But in
many places man's activities have made local
changes of great importance in the vast process.
For example, the total flow of. salt down the Colo-
rado River system may not be much greater than
it was 100 years ago, but the amount of water
transporting the salt has decreased appreciably,
thus raising the salt concentration.
Besides direct pollution, management of water
resources may result in indirect environmental
consequences. Improper irrigation practices may
provide favorable environments for vectors of
disease, such as mosquitoes for malaria or en-
cephalitis, or snails in schistosomiasis (fortunately,
the latter is not prevalent in the United States at
the present time). Other aspects of irrigation
water resource management include control of
weed seeds and insect pests.
Very little attention has been given to the opti-
mum quality of drinking water for farm animals.
While the standards of quality for human con-
sumption may not be justified here, this could be a
desirable goal because such waters often also serve
other uses on the farmstead. There are certain
contaminants which may be hazardous to live-
stock. The danger of direct infection to livestock
through the consumption of water contaminated
with pathogenic agents is definite and deserves
attention.
Private farm systems provide water for drinking
purposes, food preparation, laundry, bathing, and
preparation of products for marketing. Many farms
rely on springs or shallow wells for their water
supplies and such supplies may be contaminated.
Both the farmer and consuming public benefit
from the use of good quality water.
Dairy farming requires large quantities of water
for cooling and for washing milk-handling equip-
ment. This must be of drinking water quality even
though other uses may not require this degree of
purity.
The multiple uses of water in agriculture require
that streams and other irrigation supplies be of
such quality that potable water can be produced
economically on the farm and without serious
fluctuations in quality. Furthermore, raw water
supplies should be satisfactory usually without
treatment, for irrigation of vegetable and fruit
crops. The frequency and accuracy of monitoring
farm water supply sources should depend in part
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on the contaminating agents and the probability
of peak loading of contaminants in the raw water
source. Wherever practical, comments on monitor-
ing needs are included along with the appropriate
recommendations for criteria in this report.
Monitoring water quality
Historical water quality data should be reviewed
when considering the type, location, and frequency
of sampling. If such data are not available, a sys-
tematic sampling program to provide background
information may be necessary. Continuing water
quality data are necessary to evaluate changes
which may occur with time. By Executive Order
[Bureau of the Budget Circular A-67 (1964)],
the Department of the Interior was given responsi-
bility to coordinate collection of both water quality
and quantity data and to design and operate a na-
tional network for these purposes.
Most hydrological, climatic, and quality vari-
ables can be obtained and recorded or transmitted
in real-time at both remote and nearby locations
using sensors, transducers, and telemetering de-
vices available or under development. Improved
sensors, however, are needed for most variables,
and continued improvement of entire monitoring
systems is desirable.
In interpreting water quality characteristics,
consideration should be given to the procedures
used in measuring them. This report, therefore,
contains references to accepted chemical and bio-
logical analytical procedures. One should recognize
that these will be continually changed and im-
proved. As new methods are introduced, results
should be correlated with those obtained by pre-
viously accepted methods.
summary
and key criteria
Scope and objectives of the report
This report gives consideration to water quality
criteria of concern to agricultural users. The ob-
jectives are to describe limits of use for agricul-
tural purposes. Wherever possible, criteria are ex-
pressed as quantitative ranges. Some of these are
necessarily broad because of lack of information
or of wide flexibility in specific uses; others which
may be better understood or more critical, are
narrow. Where quantitative estimates are presently
impossible, general criteria characteristics are de-
scribed. In suggesting values for criteria, considera-
tion has been given to both health and economic
factors affecting the farmer, food processors, and
the ultimate consumers.
114
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Farmstead water supplies
In view of the wide variety of sources used
for farmstead water supplies and uncontrolled
influences of geographic location and climatic
conditions, no single set of values can realistically
be established as criteria for farmstead supplies
and accordingly most of the values are given in the
form of acceptable ranges at point of use. In de-
veloping the criteria summarized in table IV—1,
considerable reliance has been placed on the U.S.
Public Health Service Drinking Water Standards.
Water which meets these standards is generally
safe and acceptable to the user. Farmstead water
supply includes water to be used for all house-
hold purposes, washing of raw agricultural com-
modities, and for milk sanitation. Specific require-
ments above those for general farmstead use are
indicated also. This summary should be used only
in conjunction with the text of this report and
appropriate references. See table IV—1, below.
Livestock water supplies
Available literature on various substances which
occur as contaminants of drinking water for live-
stock has been reviewed. Such contaminants in-
clude inorganic elements and their salts, organic
wastes and mill effluents, pathogens and parasitic
organisms, herbicide and pesticide residues, and
radionuclides. Important and significant variables,
including nature and intake of dietary dry matter,
species, age and productivity of animals, and in-
terrelationships among the contaminating ingre-
dients, make establishment of a single set of water
purity values for livestock unfeasible. The relation-
ship of water intake to total dietary intake by live-
stock is of particular significance. For example,
much lower levels of a toxic contaminant should
be set for water if the dry feed to be ingested is
unavoidably high in the same substance. In gen-
eral, the risk of toxicity is less from water than
from feed sources.
Employment of biological indicators, such as
fish, in livestock water supplies is proposed as a
means of monitoring their safety from the stand-
point of chemical toxicity. Fish do not, however,
normally indicate presence of pathogenic orga-
nisms with sufficient sensitivity to protect livestock
from these contaminants.
Animal pathogens may occasionally enter into
a water cycle and management of water resources
can materially influence distribution of some
diseases. The involvement of the water supply in
such cases should be supported by epidemiological
studies in addition to presumptive or definitive iso-
lation from the water environment. Danger from
certain microbiological pathogens may be in-
creased in situations where water supplies are
alkaline.
In some instances, water quality standards are
set in conformity with accepted residual levels in
marketable animal tissues or products rather than
in relation to any demonstrable toxic effect upon
the animal themselves.
igation water supplies
Variations and interactions of soils, plants,
water, and climate preclude the establishment of a
single set of criteria to evaluate all water quality
characteristics for irrigation purposes. It is the
intent of this report to list tentative criteria where
possible and to suggest guidelines where specific
criteria cannot be defined. These recommenda-
tions are subject to revision as more knowledge
accumulates.
The following summary of criteria should be
used in conjunction with references to the text of
the report as noted.
Salinity
ARID AND SEMIARID REGIONS
Table IV-3 of recommended criteria for salin-
ity or total dissolved solids (TDS) assumes that
related factors set forth in this report are taken
into consideration. This includes good irrigation
practices and soil and plant variables (pp. 167-
171).
HUMID REGIONS
Where irrigation is practical in humid areas, it
is unlikely that any great accumulations of salt will
occur over a period of time. For this reason, cri-
teria suggested above for arid regions may be sig-
nificantly increased for humid regions. More ap-
propriate criteria are indicated in pages 173-174.
SAR and Sodium
Water having sodium adsorption ratio (SAR)
values between 8 and 18 may have an adverse
effect on the permeability of soils containing an
appreciable proportion of clay because its use
causes undesirable amounts of sodium to be ad-
sorbed. Where used on sensitive crops, SAR val-
115
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TABLE IV-1. Key Water Quality Criteria for Farmstead Uses.
Recommendations (at point of use)
Characteristic General farmstead uses Additional special-use requirements Page
Taste and odor Substantially free 124
Color do 124
pH ., 6.0 to 8.5 6.8 to 8.5 dairy sanitation 124
Total dissolved inorganic solids.__500 mg/l (under certain circum- 124
stances, higher levels are
acceptable).
Dissolved organic compounds No recommendations for total 124
organics.
The concentration of persistent
chlorinated organic pesticides
should not exceed the follow-
ing:
Compound jig/I
Endrin 1
Aldrm 17
Dieldrin 17
Lmdane 56
Toxaphene 5
Heptachlor 18
H. epoxide 18
DDT 42
Chlordane 3
Methoxychlor 35
Turbidity Substantially free 125
Hazardous trace elements Levels in excess of those shown 125
are grounds for rejection of a
supply:
Substances mg/l
Arsenic 0.05
Barium 1.00
Cadmium 0.01
Chromium 0.05
Cyanides 0.2
Lead 0.05
Selenium 0.01
Silver 0.05
Other trace elements Levels shown below should not be 125
exceeded if alternate sources
are available:
Substances mg/l In dairy sanitation, water should
Manganese 0.05 contain <20 mg/l potassium
Iron 0.3 and <0.1 mg/l iron and copper.
Copper 1.0
Zinc 5.0
Fluoride 0.7-1.2
Nitrate 45.0
pc/l
Radionuclides Strontium-90 10 . 125
Radium-226 3 125
In absence of above radionu-
clides, 1,000 pc/l gross ft
activity.
Nonpathogenic microorganisms_._To conform to USPHS drinking For dairy sanitation, water should 125
water standards. not contain more than 20 orga-
nisms per ml and contain not
more than 5 lypolytic and/or
proteolytic organisms per ml.
116
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TABLE IV-2. Key Water Quality Criteria for
Livestock Use
Characteristic
Recommendations
Total dissolved solids (TDS)
Hazardous trace elements:
Arsenic
Cadmium
Chromium
Fluorine
Lead
Selenium
Organic substances:
Algae (water bloom).
Parasites and
pathogens.
Dissolved organic
compounds.
Radionuclides
.< 10,000 mg/l, depend-
ing upon animal spe-
cies and ionic com-
position of the water.
_<0.05mg/l
_<0.01 mg/l
_<0.05mg/l
_<2.40mg/l
_<0.05 mg/l
_<0.01 mg/l
.Avoid abnormally heavy
growth of blue-green
algae.
Conform to epidemic-
logical evidence.
Biological accumulation
from environmental
sources, including
water, shall not ex-
ceed established,
legal limits in live-
stock products.
.Conform to recommen-
dations for farmstead
water supplies.
ues above 4 may be detrimental because of sodium
phytoxicity (pp. 155, 164). Water low in salt but
high in bicarbonate content may present a permea-
bility hazard even with low SAR values (pp. 170-
171).
Chlorides
Although not phytoxic to most crops, some
chloride phytotoxicity has been found for some
fruit crops. No limit has been established for chlo-
ride-tolerant crops because detrimental effects
from salinity per se ordinarily deter crop growth
first. For chloride-sensitive crops, chloride content
in the soil solution may range from 10 to 50 me/1
with permissible levels in irrigation water ranging
from 1 to 20 me/1 (76). More restrictive criteria
should be considered where sprinkler irrigation is
used (pp. 155-156).
Trace Elements
Toxic limits which would be generally ap-
plicable to all soils and all crops are not easily
denned. Research literature is inadequate to permit
even well-defined guidelines. The limits suggested
in table IV—15 are tentative and are designed only
to serve as guides for well-drained soils (p. 152).
TABLE IV-3. Suggested Guidelines for
Salinity in Irrigation Water
Crop response
TDS mg/l
EC1
mmhos/cm
Water for which no detri-
mental effects will usu-
ally be noticed <500 <0.75
Water which can have detri-
mental effects on sensi-
tive crops 500-1,000 0.75-1.50
Water that may have ad-
verse effects on many
crops and requiring care-
ful management prac-
tices 1,000-2,000 1.50-3.00
Water that can be used for
salt-tolerant plants on
permeable soils with
careful management
practices 2,000-5,000 3.00-7.50
1 Electrical conductivity.
Radionuclides
There are many considerations involved regard-
ing radioactivity in irrigation water (pp. 163-
164). One hazard is the potential accumulation of
a radionuclide in a soil reaching levels in excess of
that applied in the irrigation water. On the basis of
existing knowledge, USPHS Drinking Water
Standards (775) is the best guide; the standards
are: Strontium-90, 10 pc/1; radium-226, 3 pc/1.
In the absence of these radionuclides, 1,000 pc/1
gross beta activity.
Microorganisms
It is impractical to monitor irrigation water for
the numerous pathogenic organisms which may be
present (pp. 160-163). For this reason, the fol-
lowing guidelines for coliform limitations are sug-
gested for interim use subject to research confir-
mation. These are especially applicable where the
tops or roots of the irrigated crop are to be con-
sumed directly by man or livestock. The monthly
arithmetic average density of the coliform group of
bacteria shall not exceed 5,000 per 100 milliliters
and the monthly arithmetic average density of fe-
cal coliforms shall not exceed 1,000 per 100 milli-
liters. Both of these limits shall be an average of
117
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at least two consecutive samples examined per
month during the irrigation season and any one
sample examined in any 1 month shall not exceed
a coliform group density of more than 20,000 per
100 milliliters, or a fecal coliform density of more
than 4,000 per 100 milliliters.
For the control of plant pathogens, guidelines
for irrigation water are best framed in terms of
preventive measures rather than by assay pro-
cedures.
Ph
Acidity or alkalinity as such in irrigation water
is seldom directly detrimental to crop growth.
Normally, water with pH values of 4.5 to 9.0
should not present any insurmountable problems,
but a range of 5.5 to 8.5 would be more desirable
(p. 155).
Temperature
Excessively high or low temperatures in irriga-
tion water may affect crop growth and yields (pp.
157, 160). A desirable range of water tempera-
tures is from 55 to 85 F.
Suspended Solids
Sediment and suspended solids may be detri-
mental in irrigation water because of their effect
on irrigation structures and equipment and on the
soil to which the water is applied. No guidelines
are available to establish standards for either
particle size or quantity, (pp. 163, 175)
Pesticides
On the basis of the limited information avail-
able, levels of herbicides at which crop injury has
been observed are shown in Table IV-4. There
is little evidence to indicate that other pesticide
contamination of irrigation water would be detri-
mental to plant growth or accumulate in or on
edible plants in toxic concentrations under normal
use(pp. 156-157).
Biochemical Oxygen Demand (BOD) and
Dissolved Oxygen
Insufficient information is available to suggest
guidelines or to indicate that low BOD values or
dissolved oxygen content of an irrigation water as
such will have a deleterious effect on plant growth
or well-drained soils.
TABLE IV-4. Levels of Herbicides in Irrigation
Water at Which Crop Injury Has Been
Observed 1
Herbicide
Crop injury threshold in
irrigation water mg/l
Acrolein
Aromatic solvents
(xylene).
Copper sulfate
Amitrole-T
Dalapon
Diquat
Endothall Na and K
salts.
Dimethylamines
2,4-D
Dichlobenil
Fenac
Picloram
Flood or furrow: beans-60,
corn-60, cotton-80, soy-
beans-20, sugar beets-60.
Sprinkler: corn-60, soybeans-
15, sugar beets-15.
Alfalfa-> 1,600, beans-1,200,
carrots-1,600, corn-3,000,
cotton-1,600, grain sor-
ghum->800, oats-2,400,
potatoes-1,300, wheat-
1,200.
Apparently, above concentra-
tions used for weed control.
Beets (rutabaga)->3.5, corn-
>3.5.
Beets->7.0, corn-<0.35.
Beans-5.0, corn-125.0.
Corn-25, field beans-<1.0,
alfalfa->10.0.
Corn->25, soybeans->25,
sugar beets-25.
Field beans->3.5<10, grapes-
0.7-1.5, sugar beets-3.5.
Alfalfa-10, corn->10, soy-
beans-1.0, sugar beets-
1.0-10.
Alfalfa-1.0, corn-10, soybeans-
0.1, sugar beets-0.1-10.
Corn->10, field beans-0.1,
sugar beets-<1.0.
1 Data submitted by crops research division, ARS, USDA
(unpublished).
NOTE.—Where the symbol ">" is used, the concentrations in
water cause no injury. Data are for furrow irrigation unless
otherwise specified.
118
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Scope of taskforce considerations
farmstead
water supplies
The purpose of this part is to give considera-
tion to water quality criteria that will be of con-
cern in the use of water by the human farm popu-
lation for their own needs and for all other pur-
poses associated with the operation of a farm
excluding use for livestock production and the ir-
rigation of crops. Specifically included will be con-
sideration of quality criteria for water to be used
by humans for drinking, food preparation, laundry,
and bathing. Consideration will also be given to
its use for the washing and hydrocooling of fruits,.
vegetables, milk, and other animal products in
preparation for sale either on the fresh market or
to food processors.
Water for Use by the Human Farm Population:
An essential requirement for health and com-
fortable living in rural areas is that every farm
have a dependable water supply for domestic use
that is palatable, convenient, safe, and of adequate
quantity. The ability of the individual farm opera-
tor to treat water is limited to simple disinfection,
filtration, and softening. Accordingly, the quality
of the raw supply and that of the finished water
should be the same, unless otherwise indicated.
Farm water supplies can be of ground or surface
origin. Ground sources are generally regarded as
providing a more dependable supply and as being
less variable in composition than surface water.
However, it should be recognized that all supplies
are subject to pollution and care must be exercised
in both the installation and maintenance of water
systems.
In general terms, raw waters should be free of
impurities which are offensive to sight, smell, and
taste. They should be free of any significant con-
centrations of toxic substances. They should be
free also of bacteria or other living forms which
cannot be controlled or eliminated by simple proc-
essing techniques such as chlorination. The water
should be relatively free of radioactive substances
since all forms of exposure to radioactivity are
considered detrimental to man.
In the development of specific quality character-
istics, much reliance has been placed on the Drink-
ing Water Standards developed by the U.S. Public
Health Service (USPHS) for water and water sup-
ply systems (775) used by interstate carriers and
others subject to Federal quarantine regulations.
Over the years these standards have been found
to be reasonable in terms of the possibility of
compliance and acceptability of such water for
domestic use. The absence of specific references
for the quality criteria listed in this report indicates
119
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that the values have been taken from the 1962
revision of the USPHS Drinking Water Standards.
Water for Washing and Hydrocooling Raw
Farm Products: Advances in agricultural tech-
nology relating to the production and handling of
farm products has brought about changes in water
requirements. An increasing number of large
growers are preparing raw fruits and vegetables
for direct shipment to the market. Many root crops
and some fruits and vegetables are washed before
they leave the farm. Changes in fruit production
associated with mechanical harvesting and bulk
handling and emphasis on quality have made
hydrocooling of fruits a common farm practice. To
gain greater consumer acceptance of fresh fruits
and vegetables, as well as to minimize problems in
the processing of fruits and vegetables, washing
and hydrocooling of certain crops on the farm is
expected to increase in the future.
Although the use of water for hydrocooling and
washing has increased, its use in the slaughtering
and preparation of livestock for marketing has
decreased. The slaughter of animals for home use
and commercial marketing has largely been taken
over by firms specializing in this operation. Water
use in the preparation of poultry products, meat
and eggs, for market is also of little importance in
the present farm system since this operation has
largely been taken over by poultry and egg proc-
essing firms.
Water used in the washing or hydrocooling of
farm products destined for human consumption
on the farm, for sale on the fresh market, or for
delivery to a processing plant for canning, freez-
ing, or other type of preparation prior to market-
ing, should meet drinking water standards.
Water for Use in Washing Milk Handling
Equipment and Cooling Dairy Products: To
maintain and improve the quality of milk, farmers
must produce a premium product. The quality of
water used to clean milk utensils may greatly affect
the quality of milk. Since modern methods for
bulk handling milk on farms require large volumes
of water and provide many opportunities for
chance contamination of milk, water must be safe
and not injurious to milk quality.
Steadily increasing demand for water in the
rural areas due to intensified production of live-
stock, milk, and agricultural crops has required
many farm operators to develop additional sources
of water. Generally, these secondary sources are
of inferior quality and must be treated before use
in milk-handling equipment.
The grade A Pasteurized Milk Ordinance of the
USPHS (776) is accepted as the basic sanitation
standard for an ever-increasing portion of our raw
milk supply. By December 1964, the Milk Ordi-
nance (1953 edition) was the basis of the milk
sanitation laws or regulations of 37 States. The
1965 ordinance has been accepted by the Inter-
state Milk Shippers Conference as its basic sanita-
tion standard. Additional States are accepting these
requirements as the basic standard for the develop-
ment of local inspection regulations and for re-
ciprocal inspection agreements. Milk supplies for
the Interstate Milk Carrier program and for many
Government installations and programs must com-
ply with requirements of the 1965 ordinance. The
sanitation requirements for grade A raw milk for
pasteurization describe farm water supplies as a
major compliance item. Item 8r in section 7 of the
1965 ordinance defines acceptable water supplies
under this USPHS standard. It states that "water
for milkhouse and milking operations shall be
from a supply properly located, protected, and
operated, and shall be easily accessible, adequate,
and of a safe sanitary quality." Specific instruc-
tions for location of water sources, construction
of individual farm and milk plant water systems,
and disinfection of these supplies are described in
appendix D of the 1965 ordinance. The bacterio-
logical requirements for private supplies and re-
circulated cooling water are listed in appendix G
of the ordinance.
While contributing greatly to the development
of a safe, sanitary raw milk supply in this country,
the water quality standards described in the 1965
ordinance (as well as in previous USPHS model
milk codes) are inadequate. Farm water supplies
may meet these standards, yet have a detrimental
effect on the quality of our modern milk supply.
Traditional concepts of "potability" and "soft-
ness" no longer suffice in this era of mechanized
milk-handling systems. Lengthy storage of raw
milk prior to pasteurization is common in today's
marketing operation. The breakdown of normal
milk constituents by organisms able to grow at
refrigeration temperatures produces quality
changes not tolerated in fluid milk or manufactured
dairy products. Since many of these low-tempera-
ture-tolerant species of microorganisms are com-
mon soil and water contaminants, water quality
standards must be developed for farms producing
milk to prohibit the presence of those species
which can cause the breakdown of milk con-
stituents.
The following characteristics are considered es-
sential in a water supply to produce a milk supply
able to meet the demands of a modern marketing
system.
1. Sufficient quantity.—Enough water must be
120
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available every day throughout the year. Failure of
the supply, such as during a drought or freezing
weather, has serious consequences in milkhouse
sanitation. Sanitary care of milk-handling equip-
ment is an everyday must and when water is scarce,
sanitation suffers.
2. Clear, colorless, good taste, relatively soft.
—Soft water requires less detergent and gives bet-
ter cleaning. Dirty water results in dirty utensils.
Milk is susceptible to off flavors; poor tasting water
does not help.
3. Free from harmful bacteria, yeast, and
molds.—Unsafe water may cause disease. Some
bacteria cause rancid flavors in milk while others
can cause bitter, fruity, and/or other unpleasant
flavors. Yeasts and molds also contribute to flavor
defects of milk products.
4. Noncorrosive water.—Corrosion shortens
the life of piping and water heaters. Copper and
iron dissolved from piping by acid water may
cause oxidized flavors in milk products.
5. Nonscale-forming water.—Scale may clog
pipes, faucets, boilers, and water heaters (111).
General problem areas
Limitations of On-Farm Treatment: The raw
water supply available to farmers must be of such
quality that it can be used in the raw state or be
made acceptable for farmstead use with minimum
treatment such as disinfection, filtration, and/or
softening. Economic considerations alone will
prohibit use of raw supplies that require extensive
treatment to make them suitable for farmstead
uses.
Many surface waters have turbidities in excess
of what can be used effectively in home or farm
operations. The coagulation, settling, and filtration
systems used in municipal water plants are imprac-
tical for small-scale use. Pressure sand filters or
diatomaceous earth filters are not recommended
for farm use when turbidities exceed 20 units and
are not effective at this level if the supply has ex-
cessive bacteria or organic materials present.
Small in-line filters with porous rigid media or
composition disc filters are used successfully for
small systems but are not successful if high capac-
ity is desired or if turbidities exceed 5 to 10 units
(89).
Control of water hardness is desirable for do-
mestic uses and is essential for proper sanitary
control of milk contact surfaces. However, except
for supplies containing in excess of 100 to 150
mg/1 total hardness, cleaning compounds can be
formulated which provide adequate softening.
Such water may produce waterstone in heaters or
milk cooling tanks when used for ice-bank cooling
or for water-cooled compressors.
For farm supplies exceeding 100 mg/1 total
hardness, control can be effective using cation
exchange processes. When properly operated, ion
exchange systems are quite inexpensive and gen-
erally satisfactory. However, unless the equip-
ment is properly maintained and operated the
ion exchange capacity of the system will be de-
pleted and sanitation will suffer if the resultant
untreated hard water is used to prepare cleaning
solutions. At the same time, temporary hardness
chemicals (bicarbonates) will precipitate to cause
continuing heat transfer problems in water heaters
and milk coolers.
Tests for total hardness do not indicate the spe-
cific type of hardness and, consequently, the farm
water supply may contain ions other than calcium
and magnesium. These may be treated with ap-
proximately the same efficiency if specific methods
are applied but are not removed by simple systems
designed for calcium and magnesium alone.
Ion exchange softeners will filter some particles
from water but are not intended for that purpose.
Thus, if the supply also has a sediment problem,
filters should be installed ahead of the softener,
since sediment in the exchange bed will greatly
reduce the capacity of the softener. Water with a
high iron concentration will form a precipitate
which also will interfere with softener operation.
Sources of Supply Limitations: Water for farm
use can be obtained from three general sources of
supply. These include: (1) Precipitation (rain,
snow, etc.); (2) surface water (exposed bodies of
fresh water); and (3) ground water (water from
a saturated zone in the earth).
Atomospheric water is likely to be the most pure
of available supplies. When impounded in suitable
cisterns, it is a source of soft, high-quality, and
inexpensive water which may not need further
treatment for many farm uses. When used for
drinking purposes or for final rinsing of milk con-
tact surfaces, it should be treated to destroy any
pathogenic or psychrophilic bacteria.
Surface water may be defined as atmospheric
water which is not collected in cisterns, but rather
runs off to collect in streams, ponds or lakes,
swamps, etc. Such waters will collect all types of
bacteria and organic and inorganic materials as
they flow over (or through) the topsoil. All such
supplies should be treated by filtration and disin-
121
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fection before use for domestic purposes, washing
or hydrocooling of agricultural products, or in
milkhouse operations.
Surface water is subject to wide fluctuations in
temperature and mineral content as well as bac-
terial flora. Passing through decaying vegetative
matter, it may pick up colors and odors which,
though they may not be a deterrent to proper sani-
tation, may make the water objectionable for
drinking and other domestic uses.
Ground water is that which exists in a saturated
zone of the earth's crust. Most of this supply
originates as atmospheric water. Sewage and other
types of liquid waste usually have relatively little
effect on ground water quality in deep formations.
Surface water may be important to ground water
levels in the area of rainfall but may be deposited
far from the point of extraction.
The principal ground supplies are springs or
wells. Quality may differ greatly between deep and
shallow wells. Water from relatively deep wells is
usually of acceptable bacteriological quality and
can be used for drinking without treatment, al-
though it frequently has high mineral concentra-
tions. Shallow well water is seldom this pure.
While bacteria and colloidal materials are com-
monly removed as water seeps through the ground,
mineral substances are frequently dissolved to
create waters with varying degrees of hardness.
Occasionally, objectionable gases such as hydro-
gen sulfide may be dissolved which produce un-
desirable odors or tastes. More commonly, carbon
dioxide is dissolved, creating acid water with an
enhanced ability to dissolve minerals.
Shallow wells may yield appreciable numbers of
many types of bacteria and, less commonly,
yeasts. It has been reported that infectious hepa-
titis and typhoid fever are problems arising from
contaminated shallow wells in some areas (77).
This pollution may be caused by seepage of con-
taminated surface waters. Fragmented or cavern-
ous rock formations may contain crevices which
extend to the surface, particularly in limestone
areas. Shallow wells may decrease in quantity (or
dry up completely) under drought conditions.
Wells and springs should be properly disinfected
usually by chlorination after construction and after
any repair or alteration to the system.
In some locations, sand and gravel strata exist
below a stable water table. These strata may pro-
vide a dependable source of water similar in qual-
ity to that of shallow wells in the area. These sys-
tems are commonly located near a lake or stream;
however, an adequate distance should separate the
source from the system to allow for suitable nitra-
tion. The area above the infiltration system also
must be protected to prevent pollution by animals
or sewage (104).
Other Considerations Regarding Sources of
Water: Farm water supplies which are obtained
from municipal systems usually are free from
pathogenic bacteria and objectionable odors,
colors, or tastes. The primary problem with such
sources, in addition to cost considerations, is re-
lated to the control of nonpathogenic micro-
organisms and minerals occurring in the supply.
Many farm operations utilize water from sev-
eral sources during the year. Assuming the relative
quality of supplies as noted above, such combina-
tions of sources may cause problems in dairy sani-
tation. Sanitation chemicals are selected to soften
hard water and provide sufficient reserve to remove
dairy films. Several sources which are intercon-
nected in one system and then utilized as needed
during the year, may have entirely different hard-
ness and pH relationships, greatly affecting the
strength of cleaning solutions. Incomplete sanita-
tion for even a short period can cause film develop-
ment (milk and/or water) which will have a long-
term effect on raw milk quality unless removed by
supplemental treatment.
Objectionable Natural Constituents of Water:
The objectionable foreign materials commonly
present in water can be divided into several groups.
These are:
(1) Suspended matter. This includes clay, silt,
and sand. The first two are found chiefly
in untreated surface supplies while sand is
commonly associated with well supplies.
(2) Materials causing taste, odor, and color.
These impurities normally occur as the
result of one or more of the following:
dissolved organic matter, dissolved organic
gases, hydrogen sulfide, earthy constitu-
ents, algae, phenols, or other wastes. Hy-
drogen sulfide is more commonly asso-
ciated with ground supplies, while the other
impurities occur more often in surface
waters.
(3) Materials causing hardness. As water
moves on or through the earth, it may col-
lect salts of calcium and magnesium, and
to a lesser extent other minerals. While
many of these salts are of little concern in
drinking water, they can affect seriously
water to be used in cleaning and cooling.
Bicarbonates, sulfates, and chlorides are the
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common anions in farm water supplies, while cal-
cium, magnesium, and sodium are the most fre-
quently encountered cations. The bicarbonates
produce a condition known as temporary hardness.
This is the major cause of hardness problems in
farmstead water supplies, but precipitation is
rapid if bicarbonates are present. A hardness film
also forms when equipment is rinsed with hard
water. Upon evaporation of the water, hardness
minerals remain as a film on equipment.
Hardness is objectionable for most domestic
uses and causes problems in dairy sanitation since
precipitation of hardness chemicals (waterstone)
will trap milk residues. These then harbor and
provide nutrients for microorganisms which, in
turn, affect both the keeping quality and the sani-
tary quality of the raw milk supply as measured
by usual regulatory procedures. "Stone" buildups
on milk-handling equipment can only be removed
by special cleaning procedures.
(4) Iron, copper, and manganese. These ele-
ments are troublesome in the water supply
of dairy farms. They can be deposited on
milk contact surfaces during normal sani-
tation procedures, then be removed by
milk due to its slightly acid nature. When
iron and copper are present in milk in
concentrations as low as 0.1 mg/1, they
will contribute to the development of
oxidized (cardboardy) flavors (72).
These minerals may exist in the water
supply itself or result from corrosion of
the water pipes. Acid waters (pH<7.0)
are particularly troublesome in causing
corrosion and subsequent copper or iron
contamination in the water.
Iron and manganese may be found in some well
water supplies. When present, they cause a par-
ticularly objectionable red-brown stain which is
difficult to remove from surfaces being cleaned
without special techniques.
Nonpathogenic Bacterial Contaminants: Micro-
organisms are commonly present in surface waters
and waters held in reservoirs. Coliform bacteria in
a water supply have been accepted as presumptive
evidence that contamination with pathogenic spe-
cies is likely since isolation of every potential type
of pathogen is not practical at this time. Likewise,
the dairy industry has been concerned with the
coliforms since they are commonly used as an
indication of contamination with fecal pollutants
in the vicinity of the sampling location.
Many other nonpathogenic species of micro-
organisms are found in farm water supplies. Al-
though most of these are harmless, certain of them
contribute to the development of colors, odors,
tastes, and turbidity. Algae, diatoms, and protozoa
produce odors in the water but these are seldom
factors in milkhouse sanitation. One group of orga-
nisms known as "iron bacteria" actually feed on
iron pipes. These slimy, mucoid cells may multiply
in the presence of iron, produce undesirable flavors
and clog pipes or seriously depress flow rates
(200). Ropy milk is a classical example of a
fault which may be due to contaminated water.
There is considerable recent evidence that one
group of water organisms, commonly referred to
as psychrophilic (cold loving) organisms, may
have a considerable effect on the keeping quality
of raw milk. The pychrophiles include many
species capable of breaking down the fat and
proteins in milk to produce serious physical and
chemical changes in the product (165).
Research has shown farm water supplies to be
of variable but generally poor quality. While the
majority of water samples would be acceptable by
presumptive coliform determinations, tests could
indicate the supplies contained other organisms
capable of affecting milk quality (79).
Studies have shown that coliform bacteria and
most other bacteria are easily destroyed, even
when water is quite turbid. While treated waters
may satisfy standards for potable supplies, certain
psychrophilic bacteria and other spoilage orga-
nisms may survive chlorine treatment and con-
tinue to be a factor in milk quality control (6, 7,
77, 79, 82, 186). Laboratory studies indicate that
some of these putrefactive bacteria will survive
even 10 mg/1 residual chlorine (6, 7, 79, 81).
Results with iodine treatments were similar (6, 7,
79). The literature shows that certain psychro-
philic organisms are quite resistant to all sanitizing
agents (81). Sublethal doses of chlorine may effect
a temporary decrease in the growth of surviving
organisms but the rate of increase after this tem-
porary lag may be greater than that of the control
sample (32). Many of these organisms grow at
low levels of organic matter. They are actively
proteolytic, lipolytic, or putrefactive. They grow
well at temperatures barely above freezing and
may have serious consequences in present milk
handling methods where lengthy storage of raw
milk is common. As modern milk handling meth-
ods make it likely that at least small amounts of
water will enter the milk, it is evident that farm
water supplies must be free of these microorga-
nisms.
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Quality considerations
Taste and Odor
The water supply should be substantially free
of substances offensive to sight, taste, or smell.
Taste and odor in water may result from the pres-
ence of a wide variety of substances including or-
ganic compounds, inorganic compounds, and al-
gae. Knowledge concerning the source of taste and
odor components is useful in determining what
treatment, if any, is necessary to make the water
acceptable.
The odor of water is usually due to the presence
of dissolved gases such as hydrogen sulfide and
volatile organic compounds. Threshold odor values
in excess of three units (159) are generally con-
sidered objectionable. Dissolved inorganic salts
of iron, zinc, manganese, copper, sodium, potas-
sium, and others may be detected by taste. Limits
for many of these ions are listed later in this
report.
Color
The water supply should be substantially free of
color. Dissolved organic material from decaying
vegetation and certain inorganic matter cause color
in water. Occasionally, excessive blooms of algae
or the growth of aquatic microorganisms may also
impart color. While color itself is not usually ob-
jectionable from the standpoint of health, its
presence in excess of 15 color units (159) is aes-
thetically objectionable and suggests that the water
needs appropriate treatment.
Temperature
The temperature of the water supply is not an
important quality consideration for most farm-
stead uses. Where large volumes of water are to be
used for hydrocooling farm products, however, the
natural temperature can be a factor influencing its
acceptability for such use.
Ph
The pH of waters can range from 5.5 to 9.0
(777) but most surface waters fall between pH
7.0 and 8.5 (779) usually due to the presence of
bicarbonate and carbonate ions. Waters with a
pH below 6.0 can cause excessive corrosion in
plumbing systems while waters with a pH above
8.5 suggest excessive sodium. Knowledge of the
water pH is useful in determining necessary meas-
ures for corrosion control, sanitation, and ade-
quate disinfection. It is recommended that the pH
of farmstead water for milkhouse use fall between
6.8 and 8.5.
Total Dissolved Inorganic Compounds
Firm standards for total dissolved inorganic
solids are not realistic in view of the naturally
occurring difference in waters from various sources
and geographical locations. The importance of
total dissolved inorganic solids in farmstead waters
for domestic use relates largely to taste, hardness,
and laxative properties. It is desirable that the total
dissolved inorganic solids not exceed 500 mg/1.
Chlorides and sulfates should not exceed 250
mg/1. No general recommendations are appropri-
ate for sodium, magnesium, potassium, phos-
phorus, sulfur, or calcium.
Although in excess of the above recommenda-
tions, waters containing up to 5,000 mg/1 total
dissolved inorganic solids can be used if alternate
sources are not available. Under these conditions,
however, the acceptability of the water depends
upon the ionic composition of the dissolved solids
and the feasibility of treatment to remove ob-
jectionable ions.
Dissolved Organic Compounds
Determination of total dissolved organic com-
pounds in water by measurement of carbon
chloroform extractable substances (CCE) is too
involved and expensive to be considered for ap-
plication to farmstead water supplies. If surface
waters are being used, an estimate of the CCE may
be obtained from nearby municipalities using the
same or similar sources. If deep ground waters are
being used on the farmstead, the problem of total
dissolved organic compounds may be ignored
unless there is reason to expect contamination.
The organic compounds of possible concern in
connection with farmstead supplies are persistent
chlorinated organic pesticides. Although the data
currently available (55, 720, 777) indicate that
contamination of both ground and surface water
with any of these materials rarely exceeds 0.1
/xg/1 and, accordingly, is negligible in terms of
human health, it is highly desirable that water
supplies remain in such a condition. Some criteria,
such as those suggested by Ettinger and Mount
(52) are too low to be broadly applied at the
present time in water quality evaluation. It is
considered appropriate, therefore, that the permis-
sible levels of specific pesticides in a farmstead
water supply should not exceed the limits sug-
gested by the PHS advisory committee, on use of
the PHS drinking water standards. The work of
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that Committee has been described in the section
on Public Water Supplies (par. 21). These recom-
mendations are shown in table IV-5.
TABLE IV-5. Recommended Limits for
Chlorinated Organic Pesticides in
Farmstead Waters
TABLE IV-6. Allowable Concentrations of
Trace Ions in Farmstead Waters
Compound
Endrin
Aldrin
Dieldrin
Lindane
Toxaphene
Maximum
acceptable
concentra-
tion H.g/1
1
17
17
56
5
Compound
Heptachlor
H. expoxide
DDT
Chlordane
Methoxychlor
Maximum
acceptable
concentra-
tion i(g/l
18
18
42
3
35
Turbidity
The presence of suspended material such as
clay, silt, finely divided organic material, and
plankton contributes to the cloudiness or turbidity
of water. Turbidity in excess of 5 units (759) is
easily detectable in a glass of water and is usually
objectionable for aesthetic reasons. Clay or other
suspended particles may not adversely affect
health, but water containing such particles may
require treatment to make it suitable for certain
uses. Following a rainfall, variations in the ground
water turbidity may be considered an indication
of surface pollution.
Trace Elements
Attention has been given only to those trace ele-
ments which commonly occur in water supplies
or those which are regarded as being particularly
hazardous. The development of standards for
every potentially hazardous substance which may
occur in a water supply is an impossible task. The
user of farmstead water supplies should ascertain,
however, that there are no geological or environ-
mental conditions which render the supply unsafe
due to the presence of substances not covered
herein.
Table IV-6 lists the allowable concentrations of
trace ions which, if exceeded, would make a water
supply unsatisfactory for farmstead use.
The concentration of the trace substances sum-
marized in table IV-7 should not be exceeded if
other sources of water are available. Water to be
used in milkhouse sanitation should not contain
more than 0.1 mg/l of iron or copper.
Water containing more than 2.5 mg/l fluoride
is detrimental during tooth formation and should
not be used without suitable treatment (12, 191).
Substances
Maximum
limit mg/l
Arsenic 0.05
Barium 1.00
Cadmium 0.01
Chromium
(hexavalent) .. 0.05
Substances
Maximum
limit mg/l
Cyanides 0.20
Lead 0.05
Selenium 0.01
Silver 0.05
TABLE IV-7. Recommended Limits for Certain
Trace Substances in Farmstead Waters
Substances
Manganese
Iron _
Coooer
Recom-
mended
limit mg/l
0.05
0.3
1.0
Substances
Zinc . - _„
Fluoride - -_
Nitrate
Recom-
mended
limit mg/l
5.0
-- 0.7-1.2
45.0
Radionuclides
All radiation exposure is regarded as harmful
and any unnecessary exposure to ionizing radia-
tion should be avoided. The acceptability of a
farmstead water supply containing radioactive
materials should be based upon the determination
that the intake of radioactive substances from such
water when added to that from all other sources is
not likely to result in exposure greater than that
recommended by the Federal Radiation Council
(56). Supplies containing radium-226 and stron-
tium-90 are acceptable without consideration of
other sources of radioactivity if the concentrations
of these radionuclides do not exceed 3 and 10
pc/1, respectively. In the known absence of
strontium-90 and alpha-emitting radionuclides,
the water supply is considered acceptable if the
gross beta activity does not exceed 1,000 pc/1.
If the gross betta activity is in excess of this
amount, a more complete radiochemical analysis
is required to determine that the sources of radia-
tion exposure are within the limits of the radiation
protection guides.
Pathogenic and Non-pathogenic Microorganisms
The presence of any coliform organisms in a
water supply suggests fecal contamination. The
common technique used to measure coliform or-
ganisms, however, is based on a probability form-
ula and compliance with the criterion is met if
the sample is found to contain no more than one
coliform organism per 100 ml of water. If routine
chlorination or other effective means of disinfec-
tion is used, levels up to 100 coliform organisms
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per 100 ml in the raw water supply can be toler-
ated. Coliform densities above this level may re-
quire special treatments.
It should be kept in mind that negative test
results cannot be considered as an assurance of a
continuously safe supply unless the results of sani-
tary surveys and subsequent negative tests support
such a position.
In addition to limitations for coliform orga-
nisms, water used for dairy sanitation should con-
tain no more than 20 organisms of all other types
per milliliter and no more than 5 proteolytic and/
or lipolytic organisms per milliliter (111 ).1
Determination of quality
Monitoring and Periodic Checks
Water for farmstead use should be sampled and
examined for bacteriological contamination upon
completion of the supply system and when the sys-
tem is repaired or changed. Samples should be
taken also to determine the physical and chemical
characteristics of the supply at the time of initial
use of the system. Bacteriological analysis should
include testing for important groups of nonpatho-
genic bacteria in addition to usual coliform deter-
minations.
Samples of water for farmstead use should be
taken periodically during the year and analyzed
for bacteriological, physical, and chemical charac-
teristics. If there is any likelihood that composi-
tion has changed, more frequent sampling may
be necessary if the source is known to be of vari-
able quality. During a temporary shortage when
water is hauled to a dairy farm producing milk
under a sanitary code based on the USPHS grade
A Pasteurized Milk Ordinance (176), it is man-
datory that a sample of such water be taken each
month at the point of use and submitted to a
laboratory for bateriological examination. When
the quality is such that treatment is necessary to
meet USPHS standards described above, the farm
operator or his representative should make fre-
quent tests (at least weekly) to determine that the
equipment is operating properly.
1 Standard methods for the examination of dairy
products. 1960. llth ed. APHA, Inc., N.Y. Hammer,
B. W., and F. J. Babel, 1957. And, Dairy bacteriology,
4th ed. John Wiley & Sons. pp. 15-16.
Procedures for Analysis
Procedures used in the determination of water
quality factors are, for the most part, standard
methods applicable in the examination of water
regardless of its source or intended use. In view of
this fact, methods for sampling and analysis are
found in the section on Sampling and Analytical
Procedures of this report.
Specific recommendations
Discussion of Limiting Criteria
Water for use by the human farm population,
for washing and preparation of raw farm products
for marketing, and for dairy sanitation should be
potable as a minimum requirement. Also, in de-
veloping water sources, attention should be given
to assure that the supply used does not contain
microorganisms or chemicals which can cause
product deterioration or adversely affect sanita-
tion procedures.
Farms using multiple sources of water should
keep supplies separate and have each analyzed
with reference to the quality criteria previously
listed. Withdrawal from each of the several sources
should be planned and adjustments made in sanita-
tion and treatments based on the composition of
that water.
Many species of bacteria are capable of estab-
lishing cultures in unclean or corroded pipes.
Samples of water for analysis should be taken at
the outlet as well as at the source to determine
.the presence of any microbial buildup in piping
systems. Pipes may become perforated by corro-
sion, or leaks may develop at pipe joints permitting
polluted water to be drawn into the normal supply
system.
Evaluation of Recommendations—
Needs and Their Achievement
The history of American agriculture indicates
that a suitable water supply for general farm use
can be obtained usually with little trouble if at-
tention is paid to developing proper sources. The
use of low-quality water can normally be traced
to lack of knowledge as to what constitutes an
acceptable supply, rather than any inability to
correct known, undesirable conditions.
Certain nonpathogenic bacteria have the ability
to withstand high chlorine residuals. When such
bacteria are present, they may be controlled by
alternative methods.
126
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In some instances, water sources near bodies
of salt water may be contaminated with salt due
to lowering of the water table. Once contamina-
tion occurs in this manner, restoration of the
underground aquifers is not considered economi-
cally feasible.
In dairy sanitation, cleaning chemicals can be
selected to correct many problems of common, un-
desirable chemicals in the farmstead water supply.
Removal requiring expensive treatment systems
is unusual.
Water Treatment Possibilities, Including
Economics
The quality requirements for water to be used
on a farm are not difficult to meet in most cases.
Treatments which render a supply potable, com-
bined as necessary with treatments to remove un-
desirable chemicals, are sufficient for most ground
water sources.
The use of surface water should not be con-
sidered unless ground sources are undependable
or unavailable. Surface water should always be
considered contaminated and individually tailored
treatment processes must be used to make it safe
as well as satisfactory for farm uses encompassed
by this report. Farm ponds, if properly maintained,
can provide raw water of high bacteriological
quality requiring a minimum of treatment to be
made suitable for domestic and livestock uses
(100).
Microbial Contaminants and Their Control: The
common method for controlling pathogenic bac-
teria has been chlorination in any one of several
ways. Certain problem areas must be considered
if the system is to be successful. The following
are important:
(1) The chlorine demand in the raw water
supply may vary greatly. This is particu-
larly true of surface water or when it is
obtained from several sources. When chlo-
rine demand is low, the water may be
objectionable to taste because of excess
chlorine in the system. The operator may
reduce the rate at which chlorine is fed
into the system which then becomes inade-
quate when chlorine demand again in-
creases.
(2) Chlorine-feeding equipment differs greatly
in cost and design. Venturi systems which
become inoperative may disrupt the entire
water system. Sediment may be a prob-
lem in some systems and equipment should
be recommended by competent authority.
(3) Chlorine mixing must be complete and an
adequate residual maintained. The system
must allow sufficient contact time for maxi-
mum killing efficiency. This is not possible
in some types of equipment nor is it pos-
sible in systems which do not include a
mixing tank as a basic component. Com-
plete mixing is unlikely in the piping sys-
tem alone (755).
(4) An adequate supply of chlorine must be
available at all times. Chlorine residuals
must be checked and equipment inspected
on a regular basis. Human error and ne-
glect are common problems in the opera-
tion of individual, small water systems.
(5) Certain water supplies may give a false
picture of the efficiency of a chlorination
system. Nitrites, manganic manganese, or
ferric iron in water will produce a false
color when a free-chlorine residue test
is made. Water which is highly alkaline or
very cold is more difficult to disinfect. In
some hard waters, precipitates may par-
tially clog the check valves of the feeder
pump, reducing its effectiveness.
Shaw (155) has commented on some of the
problems commonly encountered in treating indi-
vidual farm water systems to remove pathogenic
bacteria. He states that:
The big problem today is not whether or not something
should be done about individual water systems, but rather
what and how. It is a problem that is at the same time
both extremely simple and frustratingly difficult.
The simple part is that the bacteriologists can tell us
what kills most pathogenic organisms and the sanitary
engineers can tell us what methods and equipment have
been in successful use for years in municipal waterplants.
The difficult part is the adaptation of proven methods
and techniques, or the development of new ones, which
will, at a low cost, automatically and surely perform an
operation that in a municipal water treatment plant re-
quires expensive equipment, constant maintenance, super-
vision, adjustment, and testing by trained personnel.
It is also reported by Shaw that about half
of the individual water supplies tested in Penn-
sylvania were found to be polluted. Many of the
water treatment devices in use are not doing an
effective job even though they satisfy regulatory re-
quirements. He points out that monthly sampling
of individual water systems "seems unreasonably
troublesome and expensive," yet the usual require-
ment of annual sampling is inadequate.
There are three common methods and many
pieces of commercial equipment which may be
used in the treatment of water in individual sys-
tems. The methods are chlorination, ultraviolet
sterilization, and heat treatment.
Chlorination is best accomplished by the method
known as superchlorination. Efficient equipment
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at a reasonable cost can be secured for adding
chlorine to water in the proper dosage to destroy
harmful microorganisms. Such chlorinators are
essentially small liquid pumps that measure out
a certain dosage of chlorine and inject it into the
correct quantity of water. Chlorinators may be
operated by an electric motor, by a belt drive
from a water pump, or by a watermeter.
An advantage of an automatic chlorinator is
that it can be used to add other chemicals to the
water to remove manganese and iron, destroy
iron bacteria, neutralize acid waters, control algae,
and correct certain tastes and odors.
Ultraviolet sterilization is a practical alternative
method of water treatment. Certain psychrophilic
bacteria, known to be able to break down the fat
and protein in milk, resist very high concentrations
of chlorine (81). Concentrations of chlorine neces-
sary to destroy viruses and protozoa which have
formed cysts are not well understood. The latter,
which are particularly chlorine resistant (64) may
be present in ground water in areas where frac-
tured rock or limestone channels exist. Recent
developments in the design of components make
ultraviolet (UV) radiation an inexpensive and
generally successful method of treatment. Re-
cently, the USPHS accepted UV purification of
water if the installation includes safety devices
which shut off the flow of water if the intensity of
the light falls below acceptable levels. Meters have
been developed to keep a permanent record of UV
treatment. Ultraviolet treatment has the advantage
that it will destroy all types of microbial life known
to be a problem in farm water supplies (70).
Limitations to the UV treatment of farm water
supplies include the fact that UV treated water
has no residual action, thus any contamination
beyond the point of treatment will pass to the
finished water supply. Periodic flushing and dis-
infection of the water distribution system must be
provided. Turbid waters will quickly coat the lamp,
reducing UV intensity. If automatic signalling
devices, installed to stop the flow of water, are not
properly treated, such coating could occur during
a period of abnormally heavy demand (as in fire-
fighting) . Insurance underwriters may cancel con-
tracts when UV systems are installed if an outlet
is not provided ahead of the treatment site for
fire protection.
Heat treatment is satisfactory for destroying
normal water flora just as UV sterilization is
advantageous for treating chlorine-resistant bac-
teria. The system simply requires heating water
to a prescribed temperature for a sufficient length
of time. An ordinary water heater can be used
if the temperature is high enough (156). Sediment
or temporary hardness will cause problems unless
removed prior to heating. When cool water is
needed, the heat must be removed, thus creating
a cost for cooling as well as heating. The water
pasteurizer has been accepted in some parts of the
country but is generally considered to be somewhat
expensive in comparison with chlorination and UV
treatment.
Removal of Iron and Manganese: Insoluble
iron and iron bacteria will intensely foul the
mineral bed and the valves of a water softener.
Therefore, it's best to remove iron and manga-
nese before the water reaches the softener.
Iron and manganese can be removed by a com-
bination of automatic chlorination and fine fil-
tration. The chlorine chemically oxidizes the iron
(forming a precipitate), kills iron bacteria, and
eliminates disease bacteria. The fine filter then
removes the iron precipitate. Some filters may
dechlorinate also. This chlorination-filtration
method corrects the iron problems and assures
disinfection as well.
Iron can be removed effectively from water by
aeration and by some types of softening equip-
ment.
Neutralization of Acid Water: Acidity of water
is usually caused by dissolved carbon dioxide.
The carbon dioxide, from decaying vegetation,
forms carbonic acid. Acid water can cause corro-
sion of the water system and release of objection-
able metallic ions. Acidity of water is easily cor-
rected by addition of a neutralizing solution.
To correct acidity and disinfect with the same
equipment, a neutralizing solution may be fed
into the water supply by mixing with the chlorine
solution. Satisfactory equipment for adding soda
ash in powdered form is also available.
Other methods for minimizing the effect of acid
water are:
(a) Installation of plastic pipe for cold-water
lines when constructing new systems;
(b) Reduction of the temperature of hot water;
and
(c) Removal of oxygen or acid constituents
from the water.
Control of Tastes and Odors: Depending upon
the cause, taste and odor can be removed or re-
duced by aeration or by treatment with activated
carbon, copper sulfate, or an oxidizing agent such
as chlorine.
Aeration is an effective treatment for water
128
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having a rotten egg odor indicating the presence of
hydrogen sulfide (commonly referred to as sulfur
water). To remove, spray the water into the air
over a collecting basin, or cause it to flow over
baffles so that the hydrogen sulfide gas will be re-
leased into the air. Protect the aeration equip-
ment so that contaminants cannot enter the water.
Activated carbon treatment consists of passing
the water through granular or powdered activated
carbon which adsorbs large quantities of dissolved
gases, liquids, and finely divided solids. This
treatment is extremely effective in taste and odor
control. Activated carbon can be used in filters
available from manufacturers of water-condition-
ing and treatment equipment.
Superchlorination also is effective in reducing
tastes and odors present in water. Add chlorine
to the water in excessive amounts (superchlorina-
tion) to provide a minimum chlorine residual of
3.0 mg/1 for a contact period of at least 5 min-
utes. Remove the excess chlorine (dechlorination)
to eliminate the objectionable taste. A good
method is to use filters of activated carbon.
Algae are the most frequent cause of taste and
odors in farm water supply systems. To control
algae, treat the water with copper sulfate or,
when feasible, cover the storage unit to exclude
sunlight. The amount of copper sulfate required
varies with the particular species or organism in-
volved. A dose of 0.3 mg/1 (1 ounce in 25,000
gallons of water) will generally control most algal
growth likely to cause trouble in drinking water.
Even this small amount will damage milk flavors
if the treated water is used in milkhouse sanitation
without removing the copper.
Softening: Hardness of water is due, in large
part, to the presence of calcium and magnesium
compounds. Water dissolves these minerals as it
passes through soil and rock formations.
Water softening is not usually considered neces-
sary or economical unless the total hardness ex-
ceeds 100 mg/1. In this case, the better and easier
cleaning obtained along with the savings in de-
tergent probably will pay for the softener.
Water softeners are simple machines and the
cost of operation is low. Before a water softener
is installed, the water should be analyzed to de-
termine how much softening capacity is required.
Most dealers who handle water softeners provide
this service.
The Water Systems Council's publication,
"Water System and Treatment Handbook," sum-
marizes methods of water treatment in a useful
table (191).
livestock
water supplies
129
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introduction and
general problem areas
Relationship of water to total diet
Domestic livestock represent an important seg-
of the complex, interdependent organization of
living things on earth. As plants are considered
the "great anabolizers," animals are the "great
converters" which provide energy and other basic
necessities in forms that are both useful and palata-
ble to mankind. It is significant that they are a part
of the world's renewable sources of energy, as
opposed to the fixed sources, such as fossil fuels.
Because of these attributes, the future of domestic
animals must be carefully guarded.
Both domestic animals and man occupy the
paradoxical position of contributing to, and being
affected by pollutants in their environment. Much
of this environment, even for land animals, is
aqueous, and water is of paramount importance
as a vehicle for metabolites and their degradation
products—hence the purity of water consumed
by livestock has far-reaching implications. There
are many ways in which livestock water supplies
may be contaminated. These may be direct, as
for example where ground water rises from a
parent soil or rock formation having unusual
mineral content—either excessive or deficient in
relation to the nutrient requirements of animals.
They may also be indirect in the sense that fertil-
izers added to aid crop production may stimu-
late biological growth (microbial, algal) in
impounded water to the point where animals con-
suming that water may be affected. These ma-
terials may also produce varied effects. They may
impede the husbandry of livestock either by caus-
ing death losses or by interfering with reproductive
processes. They may also contaminate animal
products (e.g. milk) to the point where human
consumption may be objectionable. Pollutants may
be of varied types including mineral salts, organic
growth, parasitic organisms, pesticide and herbi-
cide residues, and more recently, radionuclides.
It is important to have some understanding of the
levels of these various substances that can be
safely tolerated by livestock and the levels that
constitute hazards.
In approaching this study, it is axiomatic that
although water is universally needed and consumed
by farm animals it does not constitute their entire
ingested intake. Thus, the tolerance levels that
have been established for many substances in
livestock feed do not accurately represent the
tolerance levels in water. In this connection, some
assessment of the amounts of water consumed by
various species of livestock is useful; however, the
literature on this subject is not voluminous. Since
water is usually given ad lib., it is not customary
to measure its uptake by individual animals except
on an experimental basis. Terminology may also
sometimes be confusing. "Water consumption"
usually denotes free water drunk by an animal,
whereas "total water intake" includes the moisture
content of the feed. The former designation is more
appropriate for the purpose of this study; however,
the interaction between water and dry diet cannot
be ignored. Many factors influence the water
consumed by livestock so that generalizations be-
come unwise if not impossible. Some of the more
obvious of these factors are species, age, and con-
dition of animal; the coat covering (as related to
evaporation losses); ambient temperature, and
the nature of the diet—particularly with relation
to its moisture content. With the reservations noted
above, table IV—8 has been assembled as repre-
sentative of approximate "normal" ranges of water
consumption for various classes of livestock (1,
85,161).
TABLE IV-8. Normal Water Consumption
Animal
Water consumed,
gallons per day
Beef cattle, per head 7-12
Dairy cattle, per head 10-16
Horses, per head 8-12
Swine 3-5
Sheep and goats, per head 1-4
Chickens, per 100 birds ___ 8-10
Turkeys, per 100 birds 10-15
Effect of water on plant composition
The effects of water pollutants upon livestock
may be mediated directly through water drunk by
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the animals or secondarily through the effect of
ground water pollutants upon composition of plant
forages subsequently consumed. In some cases
plants serve as a protective buffer against animal
damage since they cannot themselves tolerate
amounts of contaminants that would be hazardous
to livestock. A case in point is boron which, al-
though required by growing plants, cannot be
tolerated by them in soil water concentrations of
over 4.0 mg/1 on a continuous basis. No evidence
has been found that such a level in drinking water
is injurious to animals. On the other hand, some
plants take up from either soil water or the parent
soil material considerably larger amounts of cer-
tain materials than animals can ingest with safety.
One of the best examples of this type of situa-
tion is the "selenium accumulator" type of plant,
like the genus Astragalus, which has been reported
to contain from 1,000 to 10,000 mg/kg of sele-
nium (143). When one considers that the toxic
level of selenium in feeds consumed by animals
on a routine basis is about 4 mg/kg, it is obvious
that plant growth cannot be accepted as a valid
criterion of safety to animals. A further example
of dangerous contamination of water, as far as
livestock are concerned, is molybdenum. In Flor-
ida, where cases of molybdenosis have occurred,
the molybdenum content of ground water varied
from 0 to 8.5 mg/1 (38) and in some instances
forages were produced that were so high in molyb-
denum that severe scouring occurred among live-
stock. It is perhaps unwise to deal with mineral
contaminants individually as distinct entities since
there are frequently metabolic interrelationships
among them. It is generally accepted, for example,
that molybdenum toxicity may be alleviated to a
considerable extent by increasing copper content
of the diet (101).
Other, less direct effects of water contamination
upon livestock production are evidenced by the
relationships of soil and irrigation water salinity
to plant growth. Here the effects are measured in
terms of reduced forage yield, or perhaps inability
to produce certain desirable forage plants, rather
than in terms of any direct action upon the animals
themselves.
Fish as indicators of water safety for
livestock
The presence of fish in a source of water for
livestock may be an excellent measurement of
toxicity and to a limited extent its acceptability
from an aesthetic viewpoint. Ultimately, livestock
standards may include aesthetic values applied to
water used by man despite the fact that animals
may consume water which is grossly contaminated
with fecal organisms, animal matter, and dissolved
substances available in the environment.
Considerable evidence is available in the sci-
entific literature suggesting lower tolerance levels
for various agricultural chemicals (including pesti-
cide residues) for fish than for livestock. Accord-
ingly, presence of living fish in agricultural water
supplies indicates their safety for livestock (105).
Some examples of individual effects in fish and
animal species are included in table IV-9.
TABLE IV-9. Examples of Fish as Indicators of
Water Safety for Livestock (105)
Material
Toxic-levels
mg/1 for fish
Toxic effects on animals
Aldrin 0.02 3 mg/kg food (poul-
try).
Chlordane 1.0 (sunfish) 91 mg/kg body weight
in food (cattle).
Dieldrm 0.025 (trout)___25 mg/kg food (rats).
Dipterex 50.0 10.0 mg/kg body
weight in food
(calves),
Endrin 0.003 (bass)_._3.5 mg/kg body
weight in food
(chicks).
Ferban,
fermate 1.0 to 4.0
Methoxy-
chlor 0.2 (bass) 14 mg/kg alfalfa hay,
not toxic (cattle).
Parathion 2.0 (goldfish)__75 mg/kg body weight
in food (cattle).
Pentachloro-
phenol 0.35 (bluegill)__60 mg/1 drinking water
not toxic (cattle).
Pyrethrum
(allethrin) __2.0 to 10.0 1,400 to 2,800 mg/kg
body weight in food
(rats).
Silvex 5.0 500 to 2,000 mg/kg
body weight in food
(chicks).
Toxaphene ___0.1 (bass) 35 to 110 mg/kg body
weight in food (cat-
tle).
Changing patterns of livestock production have
introduced some problems and variables affecting
man's activity. The economic capability to pro-
duce livestock, whether it be poultry, swine, beef,
or dairy cattle, in confinement creates a very
practical problem of sewage disposal equal in
volume to effluent from some small cities. The
problem may be made acute by the concentration
of wastes in a single drainageway with its impli-
cation of gross contamination of larger water sys-
tems particularly during rainfall periods. If fish
are able to survive in the terminal management of
131
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water on the production premise, this may be more
readily accepted as a criterion of safety than if the
only visible measurement is an anaerobic, black,
stinking, open pool of sewage. The latter situation
is often the case and public demand is strong to
induce modifications whether or not economically
feasible.
It is apparent that large livestock establishments
need help in designing practical waste disposal
systems. The system must be able to handle odors
and gases as well as solids and the net result must
not create an excessive Biological Oxygen Demand
(BOD) in the terminal water. Some operations
avoid excess contamination of flowing water by
spreading liquid manure onto fields. The BOD may
be partially satisfied by introducing air under pres-
sure into sewage, by anaerobic digestion with pro-
duction of methane and other flammable gases, or
by other procedures. The total nutrients available
in solution, however, create problems in the
aquatic environment which can readily be meas-
ured by fish livability in terminal ponds. The possi-
bility of a marketable product of fish is a reality,
but only under unusual circumstances should
public fishing be encouraged.
Fish in association with livestock will not meas-
ure the presence of pathogenic, enteric, or other
microorganisms except as biologic accumulators.
Fish disease organisms are usually of different
genera from those causing livestock diseases, al-
though some diseases, like salmon poisoning in
dogs and numerous parasitisms including fish in
their life cycles, are exceptions.
Relationship between animal and human
water quality criteria
Water is a vehicle for transmission of many
infectious diseases (viral, parasitic, and fungal)
affecting both animals and man. Generally speak-
ing, however, it is less significant than food or other
contact situations as a route of infection. Mineral
and chemical contaminants of water are hazards
from a health and economic standpoint for both
animals and man. The quality criteria for mineral
and chemical contaminants established for human
water supplies have been based primarily on ani-
mal experimentation and not human tests. Simi-
larly, the 50-percent lethal dose (LD50) for most
drugs for humans is derived from animal experi-
mentation using the chick, duck (eggs), dog,
swine, rat, and rabbit as test subjects. Desirable
quality criteria for livestock drinking water should
ultimately be no less than for man. At the same
time, it must be appreciated that a large segment
of the grazing livestock population obtains its
water from surface sources.
Livestock are maintained in an environment
where exposure to coliform and other organisms
can be an everyday experience. Remarkable ad-
vances in animal production have been accom-
plished through management practices which have
eliminated many pathogens. The more advanced
the management program, the more important
the need for water criteria which approximate
human standards. Enteric organisms and viruses
may cause serious losses where management prac-
tices allow livestock to become more susceptible
to infection through lack of immunity. Nutritional
factors may also change the resistance to disease.
Although antibiotics in poultry and swine feeds
increased weight gain and improved feed effi-
ciency, the resulting reduction and alteration of
intestinal bacteria created an environment for
those organisms resistant to the antibiotics.
There is evidence also that water is a vehicle
for the transmission of such diseases as colibacil-
losis, swine erysipelas, leptospirosis, listeriosis,
salmonellosis, streptococcosis, staphylococcosis,
and tuberculosis. Moreover, many fungus diseases
are transmitted by water although less frequently
than by other methods. Practically all of the trema-
tode, cestode, and nematode (parasitic) infections
may be waterborne. It is also suspected that many
virus diseases are waterborne. Under otherwise
ideal conditions for livestock, specific organisms
or viruses spread by water can cause explosive
epidemics and sometimes serious losses, as in the
case of amoebic dysentery and waterborne diar-
rhea.
Not infrequently, livestock are watered from
the same source which supplies the home. Here
the standards must obviously be human oriented.
Watering livestock may provide additional prob-
lems through float-controlled tanks which either
leak or concentrate toxic substances through evap-
oration. Automatic float-controlled devices for
swine and poultry are particularly likely to over-
flow and the muddy, damp environment may in-
crease the hazard of disease. If the water supply
is from deep wells and artesian aquifers, the water
itself may be safe although its mineral content
may differ materially from surface water of the
area. When spilled on the soil, this deep-well
water may create environments suitable for para-
sitisms, acid-fast infections, leptospirosis, and
other diseases not common to the neighborhood of
shallow wells and surface water supplies.
Some diseases are very dependent on water.
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Leptospirosis can be spread by urine splash to
the face of other animals, but spreading via water
is the more common and normal situation in epi-
demics. A piped water supply may not affect the
distribution of such diseases as anthrax, blackleg,
botulism, bacillary hemoglobinuria, and footrot
infections, all of which occur in circumstances in-
volving various water-related environmental fac-
tors. For example, soil and rainfall distribution
materially influence the occurrence of these dis-
eases. Preventive management practices should in-
clude a sanitary water system which does not pond
or puddle water on the yards or pastures. Such dis-
eases as dysentery, typhoid, and cholera of man
also have their counterparts in livestock produc-
tion. A pathogen-contaminated water supply
should no more be permitted for livestock than
for the human because the separation of human
and animal pathogens in their ability to cause
disease is not distinct.
The economic importance of optimum water
intakes by farm animals is obvious. Thus, palata-
bility and toxicity due to dissolve mineral salts
are of concern. The most abundant mineral salts
present in surface and deep-well waters are the
carbonates, bicarbonates, chlorides, and sulfates
of sodium, potassium, magnesium, and calcium.
Together they comprise 95 to 99 percent of the
total mineral content of most natural waters.
Water begins to decrease in palatability when the
total amount of these minerals exceeds from 500
to 1,000 mg/1, depending on the nature and com-
bination of the minerals. Beyond these limits, the
water becomes increasingly unpalatable and fi-
nally toxic. The common belief that cattle and
sheep are more tolerant to highly mineralized
waters than poultry, swine, and horses may not
be true. Limited research work indicates little
species differences in salinity tolerance when the
moisture content of the rations is similar.
Practical experience and a limited amount of
controlled experimental work indicate that chick-
ens, swine, cattle, and sheep can survive and re-
main healthy on saline waters containing up to
15,000 mg/1 of minerals such as bicarbonates,
chlorides, and sulfates of sodium and calcium and
up to 10,000 mg/1 for the corresponding salts of
potassium and magnesium. The limits of tolerance
to alkaline waters, those containing sodium and
calcium carbonates, are around 5,000 mg/1.
Surface and underground waters nearly always
contain trace amounts of toxic minerals. Of these,
lead, arsenic, selenium, chromium (hexavalent
forms), cadmium, silver, barium, and fluorine are
cumulative poisons. When present in excess, they
are not eliminated from the body fast enough to
prevent the buildup of toxic levels in the bones,
soft tissue, and other body parts. They thus be-
come hazards .to man who consumes them as well
as to the animal which may very well survive the
insult and reach market without outward notice-
able effect. Many other minerals, such as salts of
zinc, copper, manganese, and iron, are also pres-
ent. However, they are not cumulative poisons and
become toxic at much higher levels.
A quantitative mineral analysis of water is
highly informative relative to its content of lead,
arsenic, and other toxic minerals. In only a few
cases will these minerals be present in harmful
amounts. In nearly all cases, the decisive factor
affecting the suitability of water will be the amount
of sodium, potassium, magnesium, and calcium
contained.
Since no two waters are similar in their relative
content of sodium, potassium, magnesium, and cal-
cium, no attempts have been made to determine
the exact magnitude of their detrimental effects
on water and feed intakes and feed efficiencies
during the time required to develop tolerance to
them. The detrimental effects will be roughly pro-
portional to the total amount of these four minerals
in excess of 1,000 mg/1.
Variable considerations
Geographical
The foregoing discussion has implied some-
thing of the breadth and diversity of the -water
pollution situation as it bears on domestic live-
stock. Some classification of the resultant prob-
lems is possible on the basis of the variety of fac-
tors influencing pollution.
Certain geographical areas of the United States
are recognized as related to specific types of water
contamination. These may be concerned with geo-
logical soil formation, or with production patterns
indigenous to the areas in question. Examples
of the first type are the presence of boron in natural
waters of Southern California and of sulfates as
teachings from gypsum and other soil minerals in
several of the Western States. An indirect exam-
ple of the same relationship is the effect that cer-
tain alkaline soil conditions have upon the pH of
soil water and the subsequent implications for
viability of livestock disease organisms. Micro-
organisms responsible for erysipelas in swine,
sheep, and turkeys, vibrio fetus in cattle and
sheep, and vibrio dysentery ("winter dysentery")
of cattle all thrive in an alkaline medium (13).
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Nitrate toxicity, while it is still imperfectly under-
stood, tends to show some tendency toward preva-
lence in areas of the Great Plains having high-
soil fertility and a high water table.
Sulfates and their derivatives may also be used
as examples of product-oriented contamination
in discharge waters from paper mills which are
located in various regions of the country where
geographical conditions support timber growth.
Development of large-scale livestock feedlots has
generally taken place in dryer regions where dis-
ease control is easier. Consequently, specific prob-
lems of water pollution related to this industry
acquire a regional pattern.
description of major
quality considerations
Species
Some interesting species differences also exist
among livestock tolerances to water pollutants.
A pertinent example of these is the variable re-
sponse of different types of animals to salinity con-
centrations. Standards developed in western Aus-
tralia as safe upper limits for livestock are listed
in table IV-10 (122,190).
TABLE IV-10. Proposed Safe Limits of Salinity
for Livestock
Animal
Poultry
Swine
Horses
Dairy cattle
Beef cattle
Sheep (adult, dry)
Threshold salinity
concentration 1
TDS mg/1
2,860
4,290
6435
7,150
10,000
. ._ 12,000
1 Total salts, mainly NaCI.
These values should not be taken as absolute,
but rather interpreted as indicative of the signifi-
cant species variation that exists. They were de-
veloped in a subtropical environment and may not
be readily translatable to more temperate areas.
Obviously, when feed is also high in salt content,
a lower water salinity would be desirable. More-
over, when animals are consuming high-moisture
forage they can tolerate more saline water than
when they are grazing dry "bush" or "scrub."
Discussion of individual items as they
affect livestock
Mineral Salts
One of the commonest types of water contami-
nants is the mineral salts due to their ubiquitous
occurrence and their solubility characteristics.
Highly mineralized waters can cause physiological
disturbances in animals including gastrointestinal
symptoms, wasting disease, and sometimes death.
Animals subjected to physiological stresses, such
as reproduction, lactation, or rapid growth, are
particularly susceptible to mineral imbalances,
hence they pose a real threat to animal production.
It is not prudent to generalize on overall "salt"
levels in water since some salts are specifically
toxic, such as nitrates, fluorides, selenates, and
molybdates (//). "Alkalinity" of water, while it
does not represent a single polluting substance,
but rather a combination of various effects and
conditions, is a common measurement that carries
some significance. Caustic alkalinity in concentra-
tions of 50 mg/1 and 170 mg/1 has been reported
to cause diarrhea in chickens and other animals
(77). The following data are pertinent to estab-
lishment of tolerance levels for specific inorganic
elements or their salts.
The establishment of criteria for every poten-
tially hazardous material which might occur in
water is not feasible. Allowable concentrations of
certain trace elements, as listed in table IV-11, are
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TABLE 1V-11. Suggested Maximum Allowable
Concentrations of Certain Inorganic Elements
in Farm Animals' Water Supply
Substance
Suggested maximum
allowable
concentration, mg/l
Arsenic
Cadmium
Chromium (hexavalent)
Lead
Selenium
0.05
0.01
0.05
0.05
0.01
satisfactory for farm use and presumably safe for
livestock. Further data on specific mineral salts
are listed in the subsequent discussions.
Antimony may find its way into water supplies
as antimony potassium tartrate, or "tartar emetic",
since this is sometimes used as a mordant in tex-
tile and leather manufacturing (110) and for the
control of ants and other insects. The minimum
lethal oral dose of this compound for rats is listed
at 300 mg/kg body weight, however, horses can
apparently take 5.8 g and cattle 3.8 g three times
daily without harm (124).
Arsenic has long enjoyed notoriety as a poison,
but more recently, arsenicals have found some
usefulness in livestock production mainly as a
coccidiostat in poultry feeding or in "dip" solu-
tions for animals. There is also recent evidence
that arsenic functions in some way to reduce selen-
ium toxicity when present in drinking water at
levels of 5 mg/l as sodium arsenate (36). The
toxicity of arsenic depends to a considerable ex-
tent upon the form in which it occurs. Thus, LD50
doses for female rats are 112 mg/kg as elemental
arsenic or 298 mg/kg as calcium arsenate (60).
Wadsworth (185) has listed toxic dose ranges for
arsenic as shown in table IV-12.
TABLE IV-12. Proposed Toxic Dose Ranges
for Arsenic (185)
Animal
Toxic dose of As,
g/animal
Poultry 005- 0.10
Dogs 0.10- 0.20
Swine 0.50- 1.00
Sheep, goats, horses 10.00-15.00
Cattle 15.00-30.00
Beryllium is a rare element unlikely to occur in
natural waters, although it could conceivably be
involved in effluents from metallurgical plants.
Laboratory rats survived 2 years on a diet which
supplied about 18 mg/kg beryllium daily. If these
data are transposable to cattle, it has been calcu-
lated a cow could drink 250 gallons of water con-
taining 6,000 mg/l beryllium, without harm
(133).
Boron may enter water supplies naturally, from
geological boron deposits, or in the form of syn-
thetic boranes. The latter are more highly toxic
(87). The lethal dose of boric acid varies from 1.2
to 3.45 g/kg body weight, depending on the ani-
mal species (27). Concentrations of 2,500 mg/l
boric acid in drinking water have inhibited animal
growth.
Cadmium salts are found in effluent waters of'
various industrial plants, including electroplating,
textile, and chemical concerns. Ground water con-
tamination of 3.2 mg/l cadmium has been reported
from Long Island, N.Y. (88). Data on cadmium
toxicities are fragmentary. The lethal dose of cad-
mium has been set at 0.15 to 0.3 g/kg body
weight for dogs and 0.3 to 0.5 g/kg for rabbits
(124).
Chlorides may enter ground waters from a vari-
ety of sources, including natural mineral origin,
or sea water infiltration of subterranean water
supplies, from oilfield operations, and from in-
dustrial effluents (papermaking, galvanizing,
water-softening). Concentrations of chlorides of
1,500 mg/l in livestock water supplies has been
reported safe for cattle, sheep, swine, and poultry.
Chromium, in common with most of the trace
elements, appears to serve some essential func-
tion for animals in small concentrations, but also
poses a toxicity problem if present in excess. As
data for establishing a specific criterion for live-
stock use are inadequate, the criterion for farm-
stead water supplies appears to be satisfactory for
livestock as well (66).
Cobalt: The range between adequate levels of
cobalt required by animals in extremely low con-
centrations and toxic levels is quite wide. Ac-
cordingly, cobalt toxicity is a rare problem and
is more likely to arise from contamination of the
dry matter of the diet than from water contamina-
tion. Cobalt toxicity is evidenced by a striking
polycythemia in various species of animals (86).
Levels of 100 mg/l cobalt in drinking water for
rats has been reported to cause tissue damage
(124).
Copper: Little information is available on toxic
levels of copper in drinking water for livestock
although the toxic effects of copper have been ex-
tensively studied. One is led to the conclusion that
most copper toxicities are feed-related rather than
water-related. There are, however, a number of
135
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opportunities for copper contamination of water
supplies since copper in various forms is widely
used in agriculture. One reference indicates that
levels of about 160 mg/1 copper inhibits water in-
take for turkeys whereas 500 to 600 mg/1 is
"harmful" to turkeys when such water is the only
drinking water available (67). Even these levels,
however, are generally higher than those recom-
mended for control of fungus infections in turkeys,
suggesting that any damage would be accidental.
Fluorine may become a ground water contami-
nant from underlying strata containing fluorides
and may perhaps enter in effluents from certain
types of manufacturing processes. The latter,
however, are more likely to be airborne than
waterborne. The U.S. Public Health Service rec-
ommends rejection of drinking water supplies con-
taining from 1.4 to 2.4 mg/1, depending on pre-
vailing temperatures (175). It is noteworthy that
addition of up to 500 mg/1 of fluoride to either
the feed or drinking water for cattle did not raise
the fluoride level in their milk above 0.5 mg/1
(157).
Iron: Reports on direct toxicity resulting from
iron in water are not available. However, it has
been suggested that intake of water by livestock
may be inhibited if it is high in iron (164).
Lead may arise as a contaminant of ground
waters, both from natural sources (deposits of
galena) or as a constituent of various industrial
and mining effluents. A complication as far as lead
is concerned in livestock waters is caused by the
fact that it is a cumulative poison. There is a report
of chronic lead poisoning among animals by 0.18
mg/1 of lead in soft water (198), and there is
fairly general agreement that 0.5 mg/1 of lead is
the maximum safe limit in a drinking water supply
for animals (129). There is a considerable differ-
ence in the relative toxicities of various forms of
lead.
Magnesium: Some salts of magnesium, particu-
larly magnesium chloride, may contaminate
ground water supplies as a component of waste
waters from oil wells, road runoff, and industry.
Certain magnesium salts such as the sulfate caused
scouring or diarrhea among livestock; however,
the level they can tolerate safely appears to be
fairly high. It has been reported that livestock
will tolerate 2,050 mg/1 of magnesium sulfate
in their drinking water without laxative effects
(9).
Manganese: Toxicity data on manganese con-
tents in drinking water are not readily available.
However, cattle are reported to have suffered no
serious effects following dosages of up to 600
mg/kg in their diet for 20 to 45 days.
Mercury: Contamination by mercury may re-
sult from natural soil sources, tailings from lead
mining, or from a variety of chemical wastes. Like
lead, mercury is a cumulative poison and its con-
tinued ingestion should be carefully controlled.
Wide variations in responses to various mercury
salts make generalizations dangerous. For exam-
ple, the LD30 value for mercuric chloride for rats
is 37 mg/kg, while that for mercurous chloride
was 210 mg/kg (5, 158). The use of mercury in
American agriculture has been restricted.
Molybdenum salts can be significant water pol-
lution problems. Plant growth is not a sufficiently
sensitive criterion of molybdenum occurrence to
be used as an indicator of water safety for live-
stock since some plants can apparently accumulate
fairly large stores of molybdenum. Effects of mo-
lybdenum toxicity are aggravated by conditions
of copper deficiency in livestock. In Nevada, with
unusual local forage copper levels, molybdenosis
occurs only above forage levels of 5 to 6 mg/kg
for cattle and 10 to 12 mg/kg for sheep (46).
Although specific data on molybdenum toxicity
from drinking water sources are not readily avail-
able, some Florida waters where molybdenum
toxicity has occurred have contained up to 8.5
mg/1 molybdenum (35).
Nitrates: Heavy application of nitrogenous ferti-
lizer can lead to leaching of nitrates in percolating
ground waters (128). Nitrates may also be sup-
plied as end products of aerobic stabilization of
organic nitrogen in sewage lagoons. There are
some indirect effects which complicate the nitrate
contamination picture. In ruminant animals, ni-
trates may be reduced in the rumen by the micro-
flora to nitrites which then exert toxic effects on
the animals. When present in waters in high con-
centrations, nitrates may also stimulate growth
of undesirable plants.
Despite considerable interest in the potential
problems of nitrate toxicity, there are few specific
data. Campbell and others have reported met-
hemoglobinemia in cattle receiving water contain-
ing 2,790 mg/1 of nitrate.
Selenium: Another case where plants cannot
serve as satisfactory indicators for animals is
presented by selenium, as previously indicated.
In some cases drainage water from irrigated areas
has been found to contain appreciable quantities
of selenium (143). Also, some selenium reaches
ground water by leaching from seleniferous plants.
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Only in isolated cases has evidence been presented
that selenium occurs in water in sufficient amounts
to produce selenosis in man or animals. Moreover,
water containing high concentrations of selenium
is generally unpalatable to livestock (143). Un-
like certain of the other elements considered,
selenium poses an additional problem in that it
is readily transmitted through the mammary gland
to the milk (147).
Selenium is an essential trace mineral and of
special concern in the small safety range between
requirement (1 to 2 mg/kg of feed) and toxicity
(5mg/kg).
Sodium: Various salts of sodium occur in con-
siderable concentrations in the earth's crust and
these may be leached into surface waters. Also, in
some areas there is considerable production of
sodium salts from deep wells of the petroleum
industry. High concentrations of various sodium
salts in water are deleterious to both plants and
animals. Waters containing 2,700 mg/1 of Na
(as NaCl) were toxic to chicks (168) and a
threshold limit of 2,000 mg/1 of sodium for live-
stock has tentatively been suggested (160). There
are considerable differences in the sensitivities of
different species of livestock to sodium concen-
trations in water.
Sulfate: A threshold limit of 1,000 mg/1 for
sulfates in drinking water has been suggested
by Slander (160). There are reports that levels
of 2,104 mg/1 of sulfate caused progressive
weakening and death in cattle (2) and 2,500 mg/1
of sulfate caused diarrhea in dogs (19).
Vanadium: It is questionable that significant
levels of vanadium will occur in surface waters.
Little data .are available on toxic effects of vana-
dium in water per se; however, increased mortality
on a seleniferous ration has been attributed to
addition of 5 mg/1 of vanadium (115).
Zinc: There are very many opportunities for
contamination of water by zinc, both from natural
sources and from its many industrial uses. Animals
appear to tolerate significant amounts of zinc.
Rats fed water containing 50 mg/1 of zinc show
no harmful effects (3,199).
Organic Wastes and Algae: A vast number of
organic compounds too numerous to list here can
find their way into soil and surface waters as con-
taminants. Since the most numerous and perhaps
the most important of these will be discussed in the
section on herbicides and pesticides below, they
will not be further described here. Attention is di-
rected, however, to contamination of waters used
for livestock by organic matter, particularly algal
growths.
It is difficult to generalize on effects of algae
because they differ markedly. Some types of green
algae serve as food for certain aquatic species and
their harvest for use as livestock feeds has been
suggested. Other types of algae, notably the blue-
green type, are patently toxic and can cause death
both of aquatic species and of livestock. Probably
the first report of livestock poisoning by "water
bloom" was recorded in Australia in 1878 (59)
and similar descriptions have appeared since. In
late July 1946, numerous deaths occurred among
animals drinking algae-contaminated water from
upper Des Lacs Lake in North Dakota (25).
Canadian studies have implicated Aphanizome-
non, Anabaena, and Anacystis blooms in such
situations. The first-named genus was much more
plentiful than the other two and it was apparently
the major factor in toxicity. Animals were reported
to have died shortly after drinking water from a
lake containing these plants and a suspension of
the algae killed laboratory mice and rats within
20 hours.
A freshwater dinoflagellate, Gymnodinium was
apparently responsible for mass death of plankton-
feeding shad (126). Fish poisoned by phytoplank-
ton and consumed by birds have been reported to
cause their death (189), presumably a similar
fate could befall animals and man.
Pesticides and Herbicide Residues: Pesticide
and herbicide residues have been a cause of con-
cern to livestock owners from the time the agri-
culturalist first used these materials to protect
crops or livestock from pests or disease. The
cheapest diluent and spreading agent is water and
even relatively insoluble compounds are formu-
lated so they may be dispersed in water. Leftover
formulations in open containers may be consumed
by thirsty livestock, or may enter the water supply
through improper dispositions. To a lesser degree,
a water supply may be accidently contaminated
with these compounds, leading to poisoning. In
the presence of microorganisms, silt, or other
colloidal or suspended matter in water, many com-
pounds accumulate in the nonaqueous substances.
These, rather than the water itself, when assimi-
lated, provide the poisoning effects which assume
increasing importance in water supplies today.
To date, however, no reported example has been
found of toxicity in livestock due to pesticides or
herbicide contaminants of water supplies in
general.
Pesticides and herbicides, along with other com-
pounds which have dangerous properties when out
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of natural balance, are called economic poisons.
If these poisons occur in food, they may also be
considered as adulterants or additives. In addition
to the loss in healthy condition, productivity, re-
productivity, or death, the producer may suffer
further loss through condemnation of meat, milk,
or other products before they reach the ultimate
consumer. Water, much more than the terrestrial
environment, has great mobility and can carry
economic poisons and adulterants to areas remote
from the origin. It is imperative that drinking
water quality be maintained so that intolerable
levels of either economic poisons or adulterants
in livestock or their products will not occur. Such
levels do not necessarily endanger livestock health,
it should be noted.
The problem of accumulated pesticides in ani-
mal tissue is complicated by the similarity of patho-
logical changes induced by naturally occurring
dysfunctions, some of which are not clearly under-
stood. Potentiation of toxicity may occur particu-
larly in young and old animals as the result. The
effects of stress and some dysfunctions related to
steroid hormones may cause diseases in poultry
which are also induced by organic phosphates. The
interplay of arsenic in the phosphorus metabo-
lism and the role of copper in phosphorus-molyb-
denum interplays indicates the complexity which
can be influenced by residues.
Before 1940, the principal insecticides were
compounds of arsenic, lead, lime, sulfur, and fluor-
ine. Herbicides included the arsenicals, copper
compounds, oils, and chlorates. All of these com-
pounds have toxic effects and poisoning continues
to be a problem when these materials are handled
improperly. Criteria for water, on the other hand,
recognize that in the absence of demonstrable
disease these compounds should be disregarded.
Herbicides which contaminate water supplies
fall into two general categories: those which affect
the metabolism and are toxic to animals, and
growth regulators of plants. The most important
is probably sodium arsenite which is still used for
reasons of economy. Mercurial compounds used as
fungicides may occasionally enter water supplies.
Pentachlorophenol and various derivatives have
wide uses as herbicides, fungicides, and insecti-
cides, but apparently the reactivity of these com-
pounds in the presence of soil or other organic
matter is such that toxicity to livestock in water
seldom follows. Sulfur dioxide is a well known
general protoplasmic poison, but it is more toxic
as a gas than in solution. Herbicides which act
as growth regulators in plants, causing derange-
ments in plant organization and function, are not
usually a threat to livestock. The organic herbi-
cides are primarily toxicants of plants and usually
have little toxic effect on other forms of life.
Generally, they are less toxic than the solvents,
surfactants, granules, or other adjuvants used in
their formulation (151).
Since 1940, a number of organic insecticides
have come into general use. As in the case of
inorganic compounds, the action is often directed
at some important tissue or metabolic function
so that toxicity is influenced by the reactivity of
the target tissue as it is in turn acted upon or
reacts in the whole organism. The net result of
the use of organic insecticides sometimes becomes
a race between dosage which will kill and resis-
tance of the host which will protect. It is seldom
that acute poisoning of livestock is anything but
accidental, but today's public attitude is that live-
stock water as well as livestock food shall not
result in unwholesome residues in meat or other
animal products. It may be enough to follow the
rule that when the insecticide is used properly,
no unusual or long time residue problems will
follow. But a much wiser course to follow is to
use biodegradable insecticides where possible and
to phase out those which have a tendency to
accumulate.
If it is true that the principal action of the
organic insecticide is to bring about a derangement
of a metabolic pathway or enzyme system, then
it follows that under some conditions such anoma-
lies may occur naturally. Therefore, the mere pres-
ence of an insecticide, such as DDT, in the serum
or fat of a diseased animal is not proof that the
DDT is responsible for the effect. On the other
hand, there is a point beyond which the amount
of DDT or other adulterant may not occur with-
out representing a threat to health or causing
financial loss due to an accumulation in excess of
the legal tolerance for the compound.
Microbiological Pathogens: Water has assumed
a major role through the ages in the dissemination
of infectious bacteria, protozoa, and viruses. Man,
more than livestock, has profited from knowledge
of waterborne diseases. Grazing animals herded
on common pastures come in contact with orga-
nisms which find in the environment the factors for
a complete life cycle. Very few pathogenic micro-
organisms can resist desiccation, although some
form spores or encyst. Waterborne infections arise
through contamination of water supplies, life cy-
cles involving a water phase, or through organisms
with pathogenic capabilities adapting to growth
and reproduction in water.
Water quality, including pH, mineral, and or-
ganic composition, may be very important in
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the distribution of infectious diseases. Scientific
interest is usually directed at the whole problem
with little attention given to the water phase.
Some diseases are so water oriented that attention
is directed at the quality and characteristics of the
water environment as a factor in the distribution
of disease. This interest is increasing as the ecol-
ogy of waterborne diseases becomes of greater
concern.
Enteric microorganisms, including the vibrios
and amoebae, have a long record as water pollut-
ing agents. Chlorination, filtration, and other water
treatments are directed at making water safe, but
total microbial elimination in natural water appears
to be an impractical procedure for man, let alone
livestock.
The spread of animal infections through fecal
contamination of the environment is a constant
threat, but epidemiological evidence should sup-
port more criteria which directly relate specific
diseases to water. The Escherichia-Aerobacter
group of enterics is so widely distributed in nature,
feed, water, and the general environment, that
contamination of the intestinal tract can hardly
be avoided. When they escape from these innocu-
ous locations, as they sometimes do, to cause
urinary disease, abscesses, and mastitis, they are
very potent pathogens. Their invasiveness is low
and unless some stress is involved infections are
generally regarded as accidents. In contrast, Sal-
monella are more invasive and the carrier state
is easily produced and persistent, but often with-
out any general evidence of disease. This means
that waterborne epidemics follow the introduction
of specific microorganisms into the environment;
e.g., where untreated sewage continually enters
the water supply.
Water criteria directed against pathogenic mi-
croorganisms are divisible into two general areas
of concern. The purely mechanical spread of mi-
croorganisms by way of water is very important,
since desiccation is destructive of most living
agents. The mobility of water also increases the
chance of spread with greater dispersion of diluted
but infective doses of pathogenic organisms. There
is a more important aspect of water and water
management which deserves greatly expanded
study. The virulence of microorganisms is in-
fluenced by their environment. When a pathogen
enters an aqueous environment, its ability to infect
a new host may be influenced by water quality.
The reports of waterborne disease substantiate
this situation and serve as the principal basis for
criteria. With the substantial scientific base for
chemistry, soil microbiology, ecology, and geology
available to the agricultural community, the ob-
vious presence of water-related disease in one farm
area or region and its absence in another should
serve as a basis for comparison.
One of the best examples of water-related dis-
ease is bacillary hemoglobinuria, caused by an
organism found in western areas of North and
South America. This organism resembles Clos-
tridium novyi, and may be classed in several spe-
cies, Cl. hetnolyticwn, Cl. sordellii, the Newhall
strain, and possibly others. It has been linked
with liver fluke injury, but is not dependent on the
presence of liver flukes. Once the disease has been
properly diagnosed, the characteristic liver infarct
is not easily confused. The particular concern has
been the spread of this disease to new areas in
the Western States. Far from an indiscriminate
spread, each new premise is like the endemic areas
which have alkaline, anaerobic soil-water envir-
onments in which the organisms have a soil phase
outside the host animals. This disease may make
its appearance in new areas of the West when
these areas are cleared of brush and irrigated. To
avoid this problem, western irrigation waters
should be managed to avoid cattail marshes, hum-
mock grasses, and other environments of pro-
longed saturation. The significant ecological dis-
tinction is measured by pH which must persist
in alkaline ranges usually around pH 8.0.
The anthrax organism, Bacillus anthracis, is
found in a soil environment above pH 6.0. The
organism forms spores which, in the presence of
adequate soil nutrients, again vegetate and grow.
The spore is most likely the cause of infection,
coming from an "incubator area" of killed grass
found in the pasture where the loss occurred
(183). Some very rich alluvial soils may lack
the grass-kill feature, but these soils at the time
of losses are powdery and dry. The killed grass
is brown rather than blackened, a significant dif-
ference from water-drowned vegetation in general.
The spread by water of disease caused by drink-
ing water containing spores has never been proved.
Bits of hide and hair waste may be floated by
water downstream from manufacturing plants, but
very few outbreaks have been reported through
this source. Numerous outbreaks studied in recent
years have always had the "killed grass" potential.
The organism and spore are nonmotile and sink
in quiet water to the mud, where they are de-
stroyed by biological competition. It is a soil or-
ganism not adapted to survival in water.
A relatively new and widespread disease entity
in the United States, leptospirosis, is probably
the most intimately water-related disease problem
today. Criteria for the control of this disease are
simple with some exceptions. The pathogenic
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leptospira leave the infected host through urine.
They lack protection against drying and direct
animal-to-animal spread occurs through urine
splash to the eyes and nostrils of another animal.
This is most likely to occur in dogs, cattle, and
possibly swine. Rodents are a most common source
of leptospira. When caught, their voided urine
may infect man and contamination of damp forage
by rodent urine may cause infection in cattle.
Infection by leptospira may not always cause very
serious disease, as serological testing of livestock
indicates widespread exposure often without ob-
servable disease. Some serological types are more
virulent for cattle and swine and, more important,
cause the carrier problem. One of these, Lepto-
spira pomona, occurs with such regularity that,
when found in man, a livestock source is immedi-
ately sought. Similarly, another serotype, Lepto-
spira canicola, occurs in dogs, coyotes, and jackals
and these are thought of when outbreaks occur.
Most leptospira have rodent sources with some
species acting as true carriers.
The relationship of leptospirosis to water in the
infectivity cycle is many times direct; that is, water
which is contaminated by leptospira in urine infects
by way of water consumed, splashed, or inhaled
by man or animals. Birds apparently do not enter
into the leptospira cycle.
An indirect water relationship also exists when
mineral composition and pH influences continued
motility of voided leptospira. Even if growth and
multiplication does not occur, motile leptospira
are a threat for some time in this water environ-
ment. Thus, most episodes of leptospirosis are
traceable to swimming holes, ricefields, and natural
waters of definable pH and mineral composition.
The source of the leptospira is often relatively re-
mote in time and distance which on an epidemio-
logical basis indicates prolonged survival and vi-
tality in the leptospira. Active programs of study
of water survival were carried on in Montana
and Washington and have continued in Illinois,
Iowa, and Louisiana. In these States, water pH
is often neutral or alkaline within the criteria for
leptospira motility and survival. For leptospira
control, livestock cannot be allowed to wade in
water. Indirect contamination of water through
sewage is unlikely, although free-living leptospira
occur in such an environment.
Water- plays a vital role in the creation of en-
vironments leading to other anaerobic diseases of
livestock. The organisms causing these diseases are
the Clostridia and are important through spore
formation and production of toxins. For the or-
ganism, the toxins are probably nothing more than
food gathering and survival enzymes, but in the
animal they cause pronounced nervous system de-
rangements, tissue coagulation and liquefaction,
blood hemolysis, and food poisoning. Clostridia
range through many species, some of which have
no destructive characteristics. Although some, such
as Clostridium perfringens and Cl. tetani, may be-
come adapted to an enteric existence in animals,
almost all are soil adapted. Diseases associated
with the soil include gas gangrene, botulism, black-
leg of cattle, bacillary hemoglobinuria, and tetanus.
Rich organic mud, rotting vegetation, and decaying
animal matter serve as ready sources of these
organisms. Soil in a dried form contains spores,
since growth occurs in wet phase where oxygen is
reduced through utilization by other organisms.
These spores are resistant to heat and canned foods
which are not acid or sterile may allow the growth
of the Clostridia which cause disease.
Water management to avoid oxygen depletion
serves to control the anaerobic problem. Mineral
content and pH are undoubtedly important factors
but these are very seldom factors which should or
could be controlled. A system of dykes and water
level management for oxygen control in the Bear
River Marshes of Utah has reduced botulism of
wild birds. This system may ultimately fail, how-
ever, through silting and growth of water vege-
tation. Temporary and permanent areas of anaero-
bic water environment are dangerous to livestock;
some only a few feet wide are found from time to
time. These areas of water management on the
farm are important, but control is usually tempo-
rary and often only after livestock loss from the
anaerobic toxins or organisms. Livestock should
be barred from consuming blackened water not
adequately oxygenated.
The role of water in dissemination of viruses
is confused by the total ecological picture of the
several virus-host relationships. Recent advances
in virus study and nomenclature has made previous
systems of classification obsolete and any criteria
for viral pollution of water should recognize these
changes. Viruses cannot multiply except in a suit-
able living system and a variety of biological
phenomena limit this to a very narrow range of
host cells. They resemble spore-forming bacteria
in that the spore stage does not grow and multiply
outside a suitable environment. The resemblance
ends here as the bacterial spore returns to a vege-
tative form in the presence of nutrients and a
suitable environment. In water, the presence of
viruses represents a dilution which increases pro-
gressively through volume change and degradation
of the virus particle.
The epidemiology of virus infections tends to
incriminate direct contact; e.g. fomites, mechani-
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cal, and biological vectors, but seldom water sup-
plies. No clear distinction exists between fomites
and sewage nor should one be made. On-the-farm
management of water to avoid dissemination of
viruses is compounded by the use of water in
the removal of manure prior to the use of dis-
infectants or other biological control procedures.
It may, therefore, be an oversimplification that
viruses generally can be disregarded in water cri-
teria. Episodes of diseases and epidemiological
studies following them may indicate from time
to time that sewage contaminated water supplies
are incriminated in outbreaks. In herd manage-
ment of livestock virus diseases, direct contact,
manure contamination, and water contamination
are interlinked and must usually be treated as one
problem.
Viruses are classified by size, ether sensitivity,
tissue effects (which include viruses long known
to cause recognizable diseases, such as pox and hog
cholera), and by other criteria. The first two are
important in water criteria, since organization
of the infective virus particle and ether sensitivity
reflect the susceptibility of the virus particle to
degradation in a hostile environment. Small size
and ether resistance very likely indicate a greater
threat of water transmission over distances; more
complex particles with lipid envelopes destroyed
by ether may derive benefit from moisture, but
are susceptible to degradation by enzymes and
electrolytes in the sewage environment. No pur-
pose would be served by listing all viruses, but
some of those which are ether resistant may call
to mind the relationship of these viruses to sewage
contamination. These viruses are listed in table
IV-13.
TABLE IV-13. Ether-Resistant Viruses
Picornaviruses:
Polioviruses.
Coxsackie viruses—
Group A.
Group B.
Enteric cytopathic human orphan (ECHO) viruses.
Rhinoviruses.
Picornaviruses of lower animals.
Foot and mouth virus (not present in United States).
Teschen's disease of swine (not present in United
States).
African horse sickness (not present in the United
States).
Bluetongue virus of sheep and cattle.
Parasitic Organisms: Parasites serve as pollu-
tants of water supplies when part of their life
cycles involve a phase in water. Water supplies
in general carry animal forms, which are much
reduced in numbers by alum or other precipitation,
settling, sand filtration, and chlorination. After
such treatment, very few parasitic forms can sur-
vive the effects of dilution and soil filtration.
Natural waters, whether on the surface or under-
ground, may play an active role in parasitism,
dangerous not only to livestock, but to man as
well.
A careful distinction may be made between the
presence of free-living forms and parasites in
water. Livestock consume myriads of microor-
ganisms found in surface water and even very
clear underground water may actually contain
many microscopic forms. These organisms may
be digested, but sometimes they may be found
in lesions where their presence suggests they might
be related to the cause.
Parasitic protozoa include numerous forms
which are capable of causing serious livestock
losses. Most outbreaks are accomplished by direct
spread from animal to animal, but rain water
and overflow of piped water supplies may me-
chanically spread the infection. Once .manure en-
ters biologically active environments, such as
streams, ponds, or overflow vegetated areas, these
organisms rapidly lose their capability of causing
disease outbreaks. Very important in human water
criteria, these organisms may justifiably be dis-
regarded.
Some of the most important parasitic forms
for livestock water criteria are the various flukes
which develop as adult forms in man and live-
stock. Important ecological factors include pres-
ence of snails and vegetation in the water, or
vegetation covered by intermittent overflow. This
problem is very serious in irrigated areas, but only
when snails or other intermediate hosts are avail-
able for the complete life cycle. Fluke eggs passed
by the host, usually in the manure (some species,
in the urine), enter the water and hatch into mira-
cidia. These seek out a snail or other invertebrate
host where they develop into sporocysts. These
transform into redia which in turn may form other
redia or several cercariae. The cercariae leave the
snail and swim about in the water where they
may find the final host, or may encyst on vege-
tation to be eaten later. The life cycle is completed
by maturing in a suitable host and establishment
of an exit for eggs from the site of the attachment.
It is not unusual for the fluke to develop in an
unsuitable site for egg elimination and unusual
tissue reactions sometimes follow location in these
aberrant sites.
Flukes may generally be eliminated in the host
by medication or isolation, control of snails, and
control of vegetation. An unusual aspect of the
problem is water control. In areas of Florida where
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fluke of cattle was previously unknown, mineral
water flowing from artesian wells furnished a suit-
able environment for snails. This was followed by
fluke problems when carrier cattle were brought to
the pasture. The solution was to regulate the
artesian flow into tanks to conserve the artesian
pressure in the area. These measures also showed
that the black water of the swamps did not sup-
port the proper snail host. Water criteria for live-
stock disease control, therefore, include pH dif-
ferences, mineral composition of water, and other
biological factors measurable in water quality
itself.
Tapeworms of livestock, including poultry, do
not commonly utilize a water pathway. A tape-
worm of man does utilize a copepod and fish in its
life cycle.
Roundworms include numerous species which
may use water pathways in their life cycle. The
appearance of these so-called, free-living nema-
todes in a piped water supply is a cause for much
concern, but is probably of little health signifi-
cance. However, moisture is an important factor
in the life cycle of many roundworms and live-
stock are maintained in an environment where
contamination of water supplies is a possibility
every day. It is usually thought that roundworm
eggs are eaten, but water-saturated environments
provide ideal conditions for maintaining popula-
tions of these organisms and their eggs.
Parasitic roundworms probably evolved through
evolutionary cycles exemplified by the behavior
of the genus Strongyhides. Their life cycle is pri-
marily a soil-to-host phase, but serious Strongy-
loides problems evolve along drainageways
through the washdown of concrete feeding plat-
forms and other housing facilities for livestock.
although the classification of the Strongyloides
implies a reasonably restricted host range for each
species, this may be more environmental than
genetic. Certainly, the range of activity of Strongy-
loides as parasites of insects, crabs, amphibians,
and reptiles as well as mammals, indicates their
capabilities as pollutants of water.
Most parasitic roundworms complete their life
cycles without entering into a water phase, but
mosquitoes, blackflies, and other intermediate
hosts which may be associated with water man-
agement are sometimes involved. The Guinea
worm, Dracunculus, is dependent upon water, as
the adult lays eggs only when the host comes in
contact with water. Man, dogs, cats, or various
wild mammals may harbor the adult and the larva
develop in Cyclops. The life cycle is thus main-
tained in a water environment when the Cyclops
is swallowed by another suitable host.
Criteria for water concerning roundworms
would not be complete without mentioning "horse-
hair worms." Eggs are laid by the adult in water
or moist soil. The larva encyst and if eaten by an
appropriate insect will continue development to
the adult stage. The cycle may be interrupted and
if eaten again by another insect the growth to
adult form will be resumed. Worms do not leave
the insect unless they can enter water. The life
cycle is completed as free-living adults in water.
The prevention of water-born parasitisms de-
pends on interruption of the parasite's life cycle.
The most obvious is to keep livestock out of
water which carries the means of perpetuating
the cycle. Treatment for the removal of the para-
site from the host and destruction of the inter-
mediate host are the usual measures of control.
Measures for the eradication of parasitic diseases
usually require area or regional control programs.
The insidious nature of parasitisms, the lack of
spectacular mortality, or other evidence of disease
in livestock result in general unawareness of the
extent of these problems.
Radionuclides: All radiation exposure is re-
garded as harmful and any unnecessary exposure
to ionizing radiation should be avoided. The ac-
ceptability of livestock water supply containing
radioactive materials should be based upon the
determination that the intake of radioactive sub-
stances from such water when added to that from
all other sources is not likely to result in exposure
greater than that recommended by the Federal
Radiation Council (56, 57). Supplies containing
radium-226 and strontium-90 are acceptable with-
out consideration of other sources of radioactivity
if the concentrations of these radionuclides do
not exceed 3 and 10 pc/1, respectively. In the
known absence of strontium-90 and alpha-emitting
radionuclides, the water supply is considered ac-
ceptable if the gross beta activity does not exceed
1,000 pc/1. If the gross beta activity is in excess of
this, a more complete radiochemical analysis is
required to determine that the sources of radiation
exposure are within the limits of the radiation
protection guides.
Monitoring and Measurement: Chemical analy-
sis of ground and surface waters for minerals is
feasible and is an integral part of good livestock
management. The monitoring of surface waters for
other chemical toxicants (pesticides, herbicides,
etc.) which may occur at sporadic intervals (due
to usage) is very difficult. Thus, the use of fish
indicator ponds at the terminal watersheds is un-
doubtedly an economical safety precaution that
should be encouraged.
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Method of analysis is extremely important. The
organic and inorganic contents of water influence
the presence of pesticides and because these
compounds are biologically active, they tend to
accumulate in certain phases of the aquatic en-
vironment. As the result of alteration of the
environment, altered levels of pesticides may ap-
pear in an active biological role. Biological accu-
mulations represent the greatest variabilities which
affect the method of analysis.
The Agricultural Research Service of the De-
partment of Agriculture seeks to develop morbidity
and mortality records of livestock losses. Criteria
for waterborne diseases are dependent upon mass
statistics for losses which relate the incidence of
disease to the water environment. Laboratory
studies provide evidence on which to base criteria.
The occurrence of disease as the result of ecologi-
cal situations which involve water serve to prove
the validity of the laboratory observations. Without
this mass of epidemiological information, concepts
which are not applicable or unnecessarily expen-
sive may be perpetuated in relation to water man-
agement. In reference to the diseases (virus, para-
sitic, bacterial, or fungal) transmitted by water,
reliance should be placed upon epidemiological
studies to define the source of contamination and
to develop the remedial measures for control.
irrigation
water supplies
143
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introduction
Impact of irrigation on U.S. agriculture
Irrigation is an important factor in providing
food and fiber requirements of the Nation's popu-
lation. Irrigation farming not only increases pro-
ductivity of croplands, but also provides flexibility
which enables shifting from the relatively few
dryland crops that are grown without irrigation
to many other crops which may become greater
in demand. Irrigation also creates new employment
opportunities in processing and' marketing agri-
cultural products.
Among the multipurposes for which water re-
sources are developed and used, irrigation is the
largest single-purpose beneficial consumptive use.
Therefore, water quality criteria for irrigation be-
come more and more significant as water resource
developments increase within each river basin.
Early irrigation developments in the arid and semi-
arid West were largely along streams where only a
small part of the total annual flow was put to use.
Such streams contained dissolved solids accumu-
lated through the normal leaching and weathering
processes with only slight additions or increases
in concentration resulting from man's activities.
Additional uses of the resource may have concen-
trated the existing dissolved solids, added new
salts, contributed toxic elements, microbiologically
polluted the streams, or in some other way de-
graded the quality of the water for irrigation and
most other consumptive uses. More intensive de-
velopment in recent years and the generally short
water supply in most western streams has ac-
centuated water quality deterioration in a down-
stream direction. The significance of establishing
water quality criteria for irrigation can be evalu-
ated best by examining: (1) the impact of irri-
gation on long-term food and fiber production in
the United States, and (2) the effect of water
quality deterioration on that production.
An estimated total of 458 million acres of crop-
land in the United States during 1966 was utilized
for crop production, of which about 44 million
acres, located largely in the Western States, were
irrigated. This irrigated acreage, amounting to
about 10 percent of the total cropland, provides
about 25 percent of the total value of all crop
production. Value of production during the crop
year 1959, the latest year for which census data
are available, amounted to about $55 per acre
for all cropland in comparison to about $150 per
acre for irrigation land.
For the most part, irrigated farms produce
crops that cannot be grown successfully in the West
under dryland conditions.
From the value standpoint, irrigation's greatest
contribution is in the category of fruit, vegetable,
and other specialty crops. The environment of
the irrigated western areas is especially favorable
for these crops. Most of the commercial produc-
tion of apricots, artichokes, honeydew mellons,
hops, lemons, olives, dates, figs, garlic, nectarines,
prunes, English Walnuts, almonds, and filberts
come from the irrigated areas of the Western
States. During late fall, winter, and early spring,
the warm irrigated valleys of the Far West and
Southwest grow most of the Nation's supply of
fresh vegetables. The off-season production of
these fresh vegetables and fruits adds variety and
balance to the Nation's diet.
Soil-Plant-Climate interrelationships
Evaluation of water quality criteria for irri-
gation purposes must take into consideration the
interactive effects of soil, plant, and climate. Each
of these factors is highly variable. Yet, they are
important in determining the quality of water that
can be used for irrigation under a specific set
of conditions.
Soil
The physicochemical properties of a soil de-
termine the root environment that a plant en-
counters following an irrigation. The soil consists
of an organo-mineral complex which has the abil-
ity to react both physically and chemically with
constituents present in irrigation water. The degree
to which these added constituents will leach out
of a soil, remain available to plants in the soil,
or become fixed and unavailable to plants depends
largely on the soil characteristics.
In irrigated areas, a water table frequently ex-
ists at some depth below the ground surface, with
144
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a condition of unsaturation existing above it. Dur-
ing and immediately following periods of precipi-
tation or irrigation, water moves downward
through the soil to the water table. At other times,
water losses through evaporation from the soil
surface and transpiration from plants (evapotrans-
piration) may reverse the direction of flow in the
soil so that water moves upward from the water
table by capillarity. The rate of movement is de-
pendent upon water content, soil texture, and
structure. In humid and subhumid regions, this
capillary rise of water in the soil is a valuable
water source for use by crops during periods of
drought.
Evapotranspiration removes pure water from
the soil leaving the salts behind. Since salt uptake
by plants is negligible, salts accumulate in the
soil. A favorable salt balance in the root zone can
be maintained by leaching through the use of irri-
gation water in excess of plant needs. Good drain-
age is essential to prevent a rising water table
and salt accumulation in the soil surface and to
maintain adequate soil aeration.
Soils vary greatly in their physicochemical
properties; therefore, the resultant effect of a given
irrigation water quality on the plant root environ-
ment will also be quite variable.
Plant
Plants can be affected in two ways by irrigation
water quality. First, where sprinkler irrigation is
used, foliar absorption or adsorption of constitu-
ents in the water may be detrimental to plant
growth or consumption of affected plants by man
or animals. Secondly, where surface or sprinkler
irrigation is practiced, the effect of a given water
quality on plant growth is determined by the com-
position of the equilibrium soil solution. This is
the growth medium available to roots after soil
and water have reacted.
Plants vary considerably in their tolerance to
water quality constituents. Genetic considerations
apply not only to differences between species,
but to varietal differences as well. Many species
and varieties of plants have been observed for
tolerances to salinity, trace elements, pesticides,
and pathogens. A good start has been made in
classifying plant tolerance to salinity, but much
remains to be learned regarding the effects of
irrigation water.
Climate
Irrigation is necessary for intensive crop pro-
duction in arid and semiarid areas and is used to
supplement rainfall in humid areas. The need for
irrigation is determined to a large extent by rain-
fall and snow distribution; but temperature, radia-
tion, and humidity are also significant factors.
The effects of water quality characteristics on
soils and on plant growth are directly related to the
frequency and amount of irrigation water applied.
The rate at which water is lost from soils through
evapotranspiration is a direct function of tempera-
ture, radiation, wind, and humidity. Soil and plant
characteristics also influence- this water loss. Aside
from water loss considerations, water stress in a
plant as affected by the rate of evapotranspiration
will determine the plant's reaction to a given soil
condition. For example, in a saline soil at a given
water content, a plant will usually suffer more
in a hot, dry climate than in a cool, humid one.
Considering the wide variation in these climatic
variables over the United States, it is apparent that
water quality requirements also vary considerably.
Rainfall and snowmelt are also significant be-
cause they affect not only the amount of available
water in the soil, but may also be a factor in leach-
ing constituents applied in irrigation water out
of the plant root zone. Because precipitation pat-
terns are so variable, they influence the degree of
hazard presented by use of water of a given quality.
The soil, plant, and climate variables must be
considered in developing criteria for evaluation of
irrigation water quality. A wide range of suitable
water characteristics is possible even when only
a few variables are considered. Even under favor-
able conditions of soil, drainage, and environ-
mental factors, too-sparing applications of high
quality water with total dissolved solids of less
than 100 mg/1 would ultimately damage sensitive
crops such as citrus fruit, whereas with adequate
leaching water containing 500 to 1,000 mg/1 might
be used. Under the same conditions, certain salt-
tolerant field crops might produce economic re-
turns using water with more than 4,000 mg/1. Cri-
teria for judging water quality standards must take
these factors into account.
Past and current trends in
water quality classification
From the very beginning of irrigation in the
United States, farmers have observed differences
in water quality that have influenced their crops.
In some areas, they soon learned to bypass water
that contained excessive amounts of sediment or
that originated from tributaries known to be saline.
Means (106) observed in 1903 that safe salin-
ity limits previously set for irrigation water were
145
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too low. Since that time, various schemes for clas-
sification of the suitability of water for irrigation
have been developed. Scofield (152) discussed
increasing soil solution salinity through the use
of saline irrigation water and recognized the need
for use of leaching water and adequate drainage.
He established a classification system ranging from
excellent to unsuitable based upon the concentra-
tion of chlorides and sulfates. He strongly em-
phasized that the classification was applicable to
a specific region considering crops, soil, climate,
and the quantity of irrigation water relative to
rainfall.
Some of the later schemes of classification at-
tempted to establish ratings of "average" condi-
tions having general applicability. In all cases,
the interpretation of the suitability of water for
irrigation use was largely empirical. Current trends
in research are based upon relating quality of
irrigation water to specific soils and crops for
specific irrigation methods (795, 796, 797, 181).
A knowledge of the basic mechanisms involved is
fundamental to the prediction of irrigation water
effects on soils and plants. No single set of cri-
teria can currently be established to evaluate water
quality characteristics for irrigation purposes. It
is the purpose of the following discussion to point
out the various soil-plant-water-climate interrela-
tionships and how they apply to specific water
quality characteristics. Where possible, criteria or
guidelines will be designed for specific character-
istics.
water quality
considerations
for irrigation
Effects on plant growth
Irrigation is practiced primarily for the pur-
pose of increasing economic returns from agricul-
ture. Successful sustained irrigated agriculture,
whether in arid regions or in subhumid regions,
requires skillful water application based upon the
characteristics of the land and the requirements
of the crop. Through proper timing and adjust-
ment of frequency and volumes of water applied,
detrimental effects of poor quality water may often
be mitigated.
Undesirable water quality characteristics can
affect plant growth either directly or indirectly.
Plants may be affected directly by either the de-
velopment of high osmotic conditions in the plant
substrate, or by the presence of a phytotoxic
constituent in the water. In general, plants are
more susceptible to injury from dissolved con-
stituents during germination and early growth
stages (77) than at maturity. Plants affected dur-
ing early growth stages may result in complete
crop failure or severe yield reductions. Effects of
these undesirable constituents may be manifested
in suppressed vegetative growth, reduced fruit de-
velopment, impaired quality of the marketable
product or a combination of these factors. The
presence of sediment, pesticides, or pathogenic
organisms in irrigation water, which may not spe-
cifically affect plant growth, may affect the ac-
ceptability of the product. Another aspect to be
considered is the presence of elements in irrigation
water which are not detrimental to crop produc-
tion, but may accumulate in crops to levels which
may be toxic to animals or humans.
146
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Plant growth may be affected indirectly through
the influence of water quality on soil. For example,
the adsorption by the soil of sodium from water
will result in a dispersion of the clay fraction.
This decreases soil permeability and often results
in a surface crust formation which deters seed
germination and emergence. Soils irrigated with
highly saline water will tend to be flocculated and
have relatively high rates of infiltration (23). A
change to waters of sufficiently lower salt content
will reduce soil permeability and rates of infiltra-
tion by dispersion of the clay fraction in the soil.
This hazard increases when combined with high
sodium content in the water. Much depends upon
whether a given irrigation water is used continu-
ously or occasionally.
If irrigations are applied frequently enough,
and with sufficient extra amounts to leach salts
from the root zone to maintain a favorable growth
environment, irrigation water with relatively high
salt concentrations may be used indefinitely. The
degree to which a saline water can be used to
irrigate a given soil is closely related to the drain-
ability of that soil.
Other irrigation water quality considerations
may affect plant growth. Temperature of the wa-
ter, if excessively high or low, and its resultant
effect on the soil temperature in the root zone,
could depress plant growth. Soil aeration and oxy-
gen availability may be a factor deterring plant
growth if water having high BOD values is used
although no specific information is available.
Osmotic Effects
The effect of salinity, or total dissolved solids,
on the osmotic pressure of the soil solution is one
of the most important water quality considerations.
This relates to the availability of water for plant
consumption. Plants have been observed to wilt
in fields apparently having adequate water content.
This is usually the result of high soil salinity creat-
ing a physiological drought condition. Specifically,
the ability of a plant to extract water from a soil
is determined by the following relationship:
In this equation, the total soil suction (TSS) repre-
sents force with which water in the soil is withheld
from plant uptake. In simplified form, this factor
is the sum of the matric suction (MS), or the
physical attraction of soil for water, and the solute
suction (SS), or the osmotic pressure of the soil
water.
As the water content of the soil decreases due
to evapotranspiration, the water film surrounding
the soil particles becomes thinner and the remain-
ing water is held with increasingly greater force
(MS). Since only pure water is lost to the atmos-
phere during evapotranspiration, the salt concen-
tration of soil solution (SS) increases rapidly dur-
ing the drying process (97). Since the matric
suction of a soil increases exponentially on drying,
the combined effects of these two factors can pro-
duce critical conditions with regard to soil water
availability.
The dissolved solids or saline content of the soil
solution results from natural dissolution of soil
minerals and primarily from that added as irri-
gation water or fertilizers. Water moves downward
primarily through gravitational and capillary forces
until it approaches a state where further movement
is slow; then moves back toward the surface as a
result of evapotranspiration. With adequate leach-
ing, however, excess water passes through the root
zone carrying the salt towards the ground water.
Soil salinity in the root zone will vary between
irrigations, but may, under certain circumstances,
present a stable pattern over long periods of time.
Plant growth is related to salinity level of the
soil solution within the root zone. In assessing the
problem, criteria must be developed for assessing-
the salinity level of the soil solution. It is most
difficult to extract the soil solution from a moist
soil within the range of water content available
to plants. It has been demonstrated, however, that
salinity levels of the soil solution and their resultant
effects upon plant growth may be correlated with
salinity levels of soil moisture at saturation. The
quantity of water held in the soil between field
capacity and the wilting point varies considerably
from relatively low values for sandy soils to high
values for soils high in clay content. The U.S.
Salinity Laboratory developed the concept of the
saturation extract to meet this need (181). This
involves the addition of demineralized water to a
soil sample to a point at which the soil paste glis-
tens as it reflects light and flows slightly when the
container is tipped. The amount of water added is
reasonably related to the soil texture. For many
soils, the water content of the soil paste is roughly
twice that of the soil at field capacity and four
times that at the wilting point. This water content
is called the saturation percentage. When the satu-
rated paste is filtered, the resultant solution is re-
ferred to as the saturation extract. The salt con-
tent of the saturation extract does not give an exact
indication of salinity in the soil solution under field
conditions because soil structure has been de-
stroyed, nor does it give a true picture of salinity
gradients within the soil resulting from water ex-
traction by roots. Although not truly depicting
salinity in the immediate root environment, it does
147
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give a usable parameter which represents a soil
salinity value which can be correlated with plant
growth.
Salinity is most readily measured by determining
the electrical conductivity (EC) of a solution. This
method relates to the ability of salts in solution to
conduct electricity and results are expressed as
millimhos (mhosx 10~3) per cm at 25 C. Salinity
of irrigation water is expressed in terms of EC,
and soil salinity is indicated by the electrical con-
ductivity of the saturation extract (ECe).
Temperature and wind effects are especially im-
portant as they directly affect evapotranspiration.
Periods of high temperature or other factors, such
as dry winds, which increase evapotranspiration
rates, not only tend to increase soil salinity but
also create a greater water stress in the plant. The
effect of climatic conditions on plant response to
salinity was demonstrated by Magistad, et al. (99).
Some of these effects can be alleviated by more
frequent irrigations to maintain safer levels of
soil salinity. Particular problems occur where high
rates of evapotranspiration occur on soils with
low infiltration rates so that it may be sometimes
virtually impossible to replace the soil moisture
rapidly enough during the crop growing season to
prevent stress.
Plants vary in their tolerance to soil salinity and
there are many ways in which salt tolerance can
be appraised. Hayward and Bernstein (65) point
out three: (1) the ability of a plant to survive
on saline soils—salt tolerance based primarily on
this criterion of survival has limited application in
irrigation agriculture, but is a method of appraisal
which has been used widely by ecologists; (2)
the absolute yield of a plant on a saline soil—
this criterion has the greatest agronomic signifi-
cance; (3) relative yield on saline soil compared
to nonsaline soil—this criterion is useful for com-
paring dissimilar crops whose absolute yields
cannot be compared directly. The U.S. Salinity
Laboratory (181) has used the third criterion in
establishing the list of salt tolerance of various
crops shown in table IV-3 (p. 117). These salt
tolerance values are based upon the conductivity
of the saturation extract (ECC) expressed in
mmhos/cm at which a 50-percent decrement in
yield may be expected when compared to yields
of that plant grown on a nonsaline soil under
comparable growing conditions.
Work has been done by many investigators,
based upon both field and greenhouse research, to
evaluate salt tolerance of a broad variety of plants.
In general, where comparable criteria were used
to assess salt tolerance, results obtained agree quite
well with those shown in table IV-14.
Early investigations considered the question of
how increasing salinity levels in the substrate
affect plant growth i.e., is there a threshold con-
centration at which damage to the crop will occur
FIGURE IV-1. Salt tolerance of vegetable crops*
0 2468
10
' 25% i
10% 50% YIELD REDUCTION
12
14
ECe IN MILLIMHOS
16 PER CM. AT 25 C
*The indicated salt tolerances apply to
the period of rapid plant growth and
maturation, from the late seedling stage
onward. Crops in each category are
ranked in order of decreasing salt tol-
erance. Width of the bar next to each
crop indicates the effect of increasing
salinity on yield. Crosslines are placed
at 10 , 25 , and 50-percent yield reduc-
tions.
148
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FIGURE IV-2. Salt tolerance of field crops'
Barley
Sugarbeets
Cotton
Safflower
Wheat
Sorghum
Soybean . .
Sesbania
Rice (Paddy)
Corn
Broadbean
Flax .
Beans
10
ECe IN MILLIMHOS PER CM. AT 25 C
12 14 16 18 20 22
*Tr?e indicated salt tolerances apply to
the period of rapid plant growth and
maturation, from the late seedling stage
onward. Crops in each category are
ranked in order of decreasing salt tol-
erance. Width of the bar next to each
crop indicates the effect of increasing
salinity on yield. Crosslmes are placed
at 10, 25 , and 50-percent yield re-
ductions.
25%
10% 50% YIELD REDUCTION
only if that threshold were exceeded? Most studies
indicated that some damage began with any in-
crease and that there was no threshold where
damage first appeared or became markedly worse.
Recent data by Bernstein (14) give EC values
causing 10, 25, and 50-percent yield decrements
for a variety of field and forage crops from late
seedling stage to maturity, assuming that sodium
or chloride toxicity is not a growth deterrent.
These values are shown in figures 1, 2, and 3. The
FIGURE IV-3. Salt tolerance of forage crops'
Bermuda grass
Tall wheatgrass
Crested wheatgrass
Tall fescue
Barley hay
Perennial rye
Hardmggrass
Birdsfoot trefoil
Beardless wildrye
Alfalfa
Orchardgrass
Meadow foxtail . .
Clovers, alsike & red
10
ECe IN MILLIMHOS PER CM AT 25 C
12 14 16 18 20 22
25%
10% 50%
*The indicated salt tolerances apply to
the period of rapid plant growth and
maturation, from the late seedling stage
onward. Crops in each category are
ranked in order of decreasing salt tol-
erance. Width of the bar next to each
crop indicates the effect of increasing
salinity on yield. Crosslines are placed
at 10, 25, and 50-percent yield re-
ductions.
YIELD REDUCTION
149
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TABLE IV-14. Relative Tolerance of Crop
Plants to Salt, Listed in Decreasing
Order of Tolerance 1 (181).
High salt tolerance Medium salt tolerance Low salt tolerance
VEGETABLE CROPS
EC. x 10" = 12
Garden beets
Kale
Asparagus
Spinach
ECeXl03 =
EC. X10" = 10
Tomato
Broccoli
Cabbage
Bell pepper
Cauliflower
Lettuce
Sweet corn
Potatoes (White
Rose)
Carrot
Onion
Peas
Squash
Cucumber
EC.xl03 = 4
ECeXlOs=4
Radish
Celery
Green beans
EC.xl03 =
FIELD CROPS
ECeXl03 = 16
Barley (grain)
Sugar beet
Rape
Cotton
ECeXl03 =
ECeXl03 = 10
Rye (grain)
Wheat (grain)
Oats (grain)
Rice
Sorghum (gram)
Corn (field)
Flax
Sunflower
Castorbeans
ECeXl03 = 6
ECeXl03 = 4
Field beans
FORAGE CROPS (in decreasing order tolerance)
ECeXl03 = 18
Alkali sacaton
Saltgrass
Nuttall alkali-
grass
Bermuda grass
Rhodes grass
Rescue grass
Canada wildrye
Western wheat-
grass
Barley (hay)
Bridsfoot trefoil
ECeXl03 =
150
ECe X 10s = 12
White sweet-
clover
Yellow sweet-
clover
Perennial rye-
grass
Mountain brome
Strawberry clover
Dallis grass
Sudan grass
Hubam clover
Alfalfa (California
common)
Tall fescue
Rye (hay)
Wheat (hay)
Oats (hay)
Orchardgrass
Blue grama
Meadow fescue
Reed canary
Big trefoil
Smooth brome
Tall meadow
oatgrass
Cicer milkvetch
Sourclover
Sickle milkvetch
ECoXl03=4
ECeXl03 = 4
White Dutch
clover
Meadow fox-
tail
Alsike clover
Red clover
Lad i no clover
Burnet
ECeXl03 =
High salt tolerance
Medium salt tolerance
Low salt tolerance
FRUIT CROPS
Date palm
Pomegranate
Fig
Olive
Grape
Cantaloupe
Pear
Apple
Orange
Grapefruit
Prune
Plum
Almond
Apricot
Peach
Strawberry
Lemon
Avocado
1 The numbers following ECe X 103 are the electrical con-
ductivity values of the saturation extract in millimhos per
centimeter at 25 C associated with 50-percent decrease in yield.
data suggest that the effects of ECe values pro-
ducing 10 to 50-percent decrements (within a
range of ECe values of 8 to 10 mmhos per cm
for many crops) may be considered approximately
linear, but for nearly all crops the rate of change
AV
in yield per unit change in ECe,
AECe
either
steepens or flattens slightly as the yield decrements
increase from less than 25 to more than 25 per-
cent. Bernstein (14) also points out that most
fruit crops are more sensitive to salinity than are
field, forage, or vegetable crops. Rootstock and
varietal differences in salt tolerance of fruit crops
are so large that it would be meaningless, for most,
to give crop tolerances. The data also illustrate the
highly variable effect of ECe values upon different
crops and the nonlinear response of some crops to
increasing concentrations of salt.
In considering salt tolerances of crops, it should
be noted that ECC values are used. These values
are correlated with yields at field moisture content.
If soils are allowed to dry out excessively between
irrigations, yield reductions are much greater since
the total soil water stress is a function of both
matric suction and solute suction and increases
exponentially on drying. Good irrigation manage-
ment can minimize this hazard.
Relative salt tolerance values may vary ac-
cording to stage of growth (17). The germinating
seedling is usually most sensitive to salinity as
salt tends to accumulate in the surface few inches
of soil. This was demonstrated for a group of
grain and pasture plants in west Australia (113).
Bernstein (14) points out that some plants, such
as sugar beets, are sensitive to salinity during
germination; others are affected more during early
seedling growth, and well-established plants will
usually be more tolerant than new transplants.
-------
Salt tolerance may affect the marketable por-
tion of the plant. In some instances, vegetative
growth is more affected than fruiting and vice
versa (8, 75,95).
A 50-percent yield decrement may be within
the profitable production range for field and forage
crops in certain cases; but a yield decrement as
little as 15 percent, or a normal yield accompanied
by a deterioration of quality, might be sufficient
to eliminate most of the profits from fruit and
vegetable enterprises having a narrow margin of
income over costs.
Nutritional Effects
Plants require a balanced nutrient content in
the soil solution to maintain optimum growth. Use
of saline water for irrigation may or may not
significantly upset this nutritional balance depend-
ing upon the composition, concentration, and vol-
ume of irrigation water applied.
Some of the possible nutritional effects were
summarized by Bernstein (14) as follows:
High concentrations of calcium ions in the soil solu-
tion may prevent the plant from absorbing enough
potassium, or high concentrations of other ions may af-
fect the uptake of sufficient calcium.
Different crops vary widely in their requirements for
given nutrients and in their ability to absorb them. Nu-
tritional effects of salinity, therefore, appear only in
certain crops and only when a particular type of saline
condition exists.
Some varieties of a particular crop may be immune to
nutritional disturbances while other varieties are severely
affected. High levels of soluble sulfate cause internal
browning (a calcium deficiency symptom) in some let-
tuce varieties, but not in others. Similarly, high levels of
calcium cause greater nutritional disturbances in some
carrot varieties than in others. Chemical analysis of the
plant is useful in diagnosing these effects.
At a given level of salinity, growth and yield are de-
pressed more when nutrition is disturbed than when nu-
trition is normal. Nutritional effects, fortunately, are not
important is most crops under most saline conditions;
when they do occur, the use of better adapted varieties
may be advisable.
Many variables are involved and each adverse
condition must be diagnosed and treated accord-
ingly.
Phytotoxic Substances and Specific Ion Effects
In addition to the effect of total salinity on os-
motic soil-plant relations, individual ions may have
varying effects on plant growth. These ions include
both common and trace elements occurring natu-
rally in irrigation water, those introduced by man's
activities, and those which enter the soil solution
through a reaction between the soil and the irri-
gation water. Considerable information is avail-
able regarding the effects of nutritional balance of
the major plant nutrients. Although complicated
by interactive effects of soil and plant character-
istics, these nutritional effects are not as serious as
phytotoxicity which may be caused by trace ele-
ments or specific ions.
Trace elements are those which normally occur
in water or soil in very small quantities. Some
may be essential for plant growth in very small
amounts while others are nonessential. Some of
these elements do not occur naturally in most
waters or soils, but will be discussed here since
they may enter water supplies as a result of in-
dustrial pollution.
When an element is added to the soil in toxic
amounts, it may combine with it to give either of
two results. First, it may decrease in concentra-
tions so that it is no longer toxic. Second, it may
increase the store of that element in the soil. If
the process of adding irrigation water containing
a toxic level of the element continues, a steady
state will be approached with time in which the
amount of the element leaving the soil in the
drainage water will equal the amount added with
the irrigation water, and no further change in
concentration in the soil will occur.
In many cases, these elements are held very
strongly by soils and in some cases, they may
be toxic in relatively low concentrations. There-
fore, irrigation water containing toxic levels of
trace elements may be added for many years
before steady state is approached. A situation ex-
ists then where toxicities may develop in years,
decades, or even centuries from the continued ad-
dition of polluted irrigation waters. The time would
depend on factors apart from properties of the
water itself. Changes in technology and economy
could easily alter circumstances significantly in
such a long time.
Genetic differences in tolerance of plants to
different elements or ions has been mentioned.
Variability among species is well recognized. Re-
cent investigations by Foy (58), working with
soluble aluminum in soils, has demonstrated that
there is also variability among varieties within
a given species. This suggests the possibility of
breeding varieties to minimize phytotoxicity which
may result from a constituent in irrigation water.
Research dealing with effects of trace elements
on plant growth does not permit, in general, any
conclusions regarding threshold values beyond
which specific plants will react unfavorably. Most
studies have been carried out with several plant
species in sand or solution cultures under a wide
variety of environmental conditions. It is difficult
151
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to extrapolate from these sand and solution cul-
tures to soil conditions. Toxic limits determined in
solution cultures might apply to irrigation water
if it were not for the fact that soil conditions could
influence the element's availability to the plant.
Comprehensive reviews of literature dealing with
trace element effects on plants have recently been
published (20, 35, 105). Another reference (65)
deals with reactions of trace elements in soils.
Additional research is needed to predict reactions
between ions in irrigation water and various soil
types, and the resultant effect on various plant
species.
In developing a workable program of acceptable
limits for trace element pollution of irrigation
waters, three considerations should be recognized:1
(1) The inherent difficulty of establishing gen-
eralizations. Many factors affect the uptake
of and tolerance to trace elements. The
most important of these being genetic
variability of plants and animals, reactions
within the soil, and nutrient interactions,
particularly in the plant.
(2) A system of tolerance limits must, to the
greatest extent possible, provide sufficient
flexibility to cope with the more serious
factors above.
(3) At the same time, restrictions must be
defined, as precisely as possible.
To translate these considerations into workable
recommendations, two types of soil groupings that
may be irrigated are defined:
(a) Lands having a significant fraction of well-
drained soils classified as sands, loamy
sands, or sandy loams.
(b) Lands made up principally of finer textured
soils and generally more slowly drained.
Individual minor element limits for water to
be used on type 'a' lands are calculated assuming
that steady state may be approached in a relatively
short period of time and, therefore, that the con-
centration in irrigation waters approximates that
of the soil solution. In areas where irrigation
water accounts for most of the water applied to a
field, the values may have to be adjusted down-
ward to allow for concentration in the soil.
Upper limits that may be set for minor element
tolerances in water for type 'b' lands are somewhat
more arbitrary. They are drawn largely from maxi-
mum safe fertilizer additions that might be applied
to soils under the most favorable conditions for
fixing the element in the soil. The term "short
time" used in table IV-15 means a period of
time as long as two decades.
It is beyond the scope of this report to present
a critical literature review on phytotoxic ions.
Some references are cited to illustrate both the
importance and the complexity of the problem.
Emphasis must be placed, however, on research
needs. Due to the vast scope of the problem, it
is recommended that research be initiated as prob-
lems arise to derive specific recommendations.
The following list of trace element effects indicate
in part the potential problem and suggested trace
element tolerances for irrigation waters are shown
in table IV-15.
Aluminum: Aluminum toxicities to plants have
been reported for both acid and alkaline condi-
tions, but are probably of little consequence at
near-neutral pH values. One milligram per liter
is taken as the tolerance limit, even though sev-
eral reports of toxic effects have been observed
at 0.5 mg/1 (35). The reason for this is that even
sandy soils could be expected to reduce aluminum
toxicities somewhat and management practices
could be used to avoid marginal toxicities.
Arsenic: Arsenic may be present in fairly high
concentrations without inducing injury to some
plants such as lemons and sudan grass (35), but
toxic effects on other species have been observed
down to 1 mg/1 (105). This value is selected as
the tolerance level here, but a better understand-
ing of the effects of management practices on
the uptake of arsenic might indicate that a higher
value could be used.
TABLE IV-15. Trace Element Tolerances for
Irrigation Waters
Element
For water used
continuously on all
soils
For short-term use
on fine textured
soils only
1 Basic information on trace elements was supplied by
f. F. Hodgson of the U.S. Soil, Plant, and Nutrition
Laboratory, Ithaca, N.Y.
mg/l mg/1
Aluminum 1.0 20.0
Arsenic 1.0 10.0
Beryllium 0.5 1.0
Boron 0.75 2.0
Cadmium 0.005 0.05
Chromium 5.0 20.0
Cobalt 0.2 10.0
Copper 0.2 5.0
Fluorine C) C)
Iron O O
Lead 5.0 20.0
Lithium 5.0 5.0
Manganese 2.0 20.0
Molybdenum 0.005 0.05
Nickel 0.5 2.0
Selenium 0.05 0.05
Tin O f)
Tungsten (*) (l)
Vanadium 10.0 10.0
Zinc 5.0 10.0
1 See text.
152
-------
Beryllium: Beryllium is toxic to both animals
and plants. Growth of beans has been inhibited at
0.5 mg/1 (20), and this value is selected as the
tolerance limit. Beryllium toxicity will be moder-
ated by reaction with soils, but because it repre-
sents a relatively serious problem, its limits for
water use even for type 'b' land should be restricted
to 1 mg/1 until better information is available on
its uptake from soils.
Boron: Boron is an essential plant micronu-
trient almost up to concentrations of 0.5 mg/1
in irrigation water. However, boron in irrigation
water has caused destruction of, or damage to,
sensitive crops when concentrations in the irri-
gation water are somewhere between 0.5 and 1.0
mg/1. Most of the work on boron, done under the
leadership of Eaton (49), found a range of toler-
ance of crops, as shown in table IV-16. Water
containing more than 4 mg/1 of boron is generally
unsatisfactory for all crops. In general, sensitive
crops will show slight to moderate injury at boron
levels of 0.5 to 1.0 mg/1; semitolerant, 1.0 to 2.0
mg/1; and tolerant crops, 2.0 to 4.0 mg/1. In terms
of content in the soil saturation extract, a limit
of 0.7 mg/1 of boron is considered safe. Probably
the effect varies inversely with the percentage of
applied water that is passed through the root
zone, but this has not been evaluated. Most prob-
lems of excess boron have been encountered in
waters derived from the coast range mountains
of California and from the Hot Creek area in the
Owens Valley of California on the eastern slope
of the Sierra Nevada Mountains.
Cadmium: Cadmium toxicities have been impli-
cated in hypertensive diseases of man. Its contri-
bution to pollution, therefore, bears very close
scrutiny. Present understanding of the problem is
sufficiently limited so that cadmium will definitely
require reappraisal as evidence accumulates for
or against its toxicity and as understanding of its
behavior in the soil-plant-animal chain is im-
proved. The tolerance limit of 0.005 mg/1 is sug-
gested assuming: (1) reported toxicities are valid
(88, 149, 150); (2) cadmium behaves similarly
to zinc in its uptake by plants and reactions with
soil. It is very likely that higher levels of cadmium
could be regulated by appropriate management
practices; but in the absence of yield depression,
farmers have little inducement to employ such
practices.
Chromium: Both the chromic and chromate
ions display toxicities. Use of large amounts of
chromium for processes, such as tanning, increase
the importance of controlling this element.
Tolerance to the two ions varies with plant
species, but more sensitive plants are adversely
affected at about 5 mg/1 for each ion (35).
The chromic ion could be expected to combine
fairly strongly with neutral soils so that class 'b'
soils could likely tolerate considerably more
chromic ion than the above value. There is not
sufficient information available on chromate ion
to recognize the presence of type 'b' situations for
this ion. Furthermore, the possibility of oxidizing
chromic to chromate ions is too great to include
water of a higher chromium content for irrigating
alkaline soils of type 'b' lands even when the chro-
mic ion is present in the water, until further in-
formation is available.
Cobalt: Cobalt toxicities have been observed on
several species grown in sand culture. On the other
hand, field occurrence, of cobalt toxicity is rare.
The tolerance limit suggested here is somewhat
higher than the 0.1 mg/1 cobalt which has been
observed to be toxic to tomato plants. It is felt
that management practices should be capable of
relieving marginal toxicities of this element (105).
Copper: Copper toxicities have been observed
at copper concentrations as low as 0.1 mg/1 in
nutrient solution (35, 105). A value of twice this
is taken for the tolerance limit for water for type
TABLE IV-16. Relative Tolerance of Plants to
Boron (181)
[In each group, the plants first named are considered as being
more tolerant and the last named more sensitive.]
Tolerant
Athel (Tamarix
asphylla)
Asparagus
Palm (Phoenix
canariensis)
Date palm (P.
dactyl ifera)
Sugar beet
Mangel
Garden beet
Alfalfa
Gladiolus
Broadbean
Onion
Turnip
Cabbage
Lettuce
Carrot
Semitolerant
Sunflower
(native)
Potato
Acala cotton
Pima cotton
Tomato
Sweetpea
Radish
Field pea
Ragged Robin
rose
Olive
Barley
Wheat
Corn
Milo
Oat
Zinnia
Pumpkin
Bell pepper
Sweet potato
Lima bean
Sensitive
Pecan
Black walnut
Persian (Eng-
lish) walnut
Jerusalem arti-
choke
Navy bean
American elm
Plum
Pear
Apple
Grape (Sulta-
nina and
Malaga)
Kadota fig
Persimmon
Cherry
Peach
Apricot
Tnornless
blackberry
Orange
Avocado
Grapefruit
Lemon
153
-------
'a' lands. Copper combines strongly with most
soils as evidenced by the many soils that have been
treated for decades with copper sulfate as a fungi-
cide without displaying copper toxicities. Only
water irrigating sands very low in organic matter
would need to remain classified for use on type 'a'
lands. Limits for water to be used on type 'b' lands
could safely vary up to at least 5 mg/1.
Iron: Iron is not likely to be a problem with
irrigation waters. In those instances where im-
balances due to excess iron develop, they can be
controlled with management practices.
Fluoride: The most serious effect of fluoride is
not its effect on plant growth, but the ultimate
effect on the consuming animal including man.
The uptake of fluoride by plants is restricted
both by a combination of the element with soils,
favored by low pH, and a discrimination against
fluoride by plant roots (20). Some plant species
do accumulate large amounts of fluoride, but for
the most part they are not consumed by man or
livestock. The principal pathway for fluoride poi-
soning then is through direct imbibition of toxic
waters or plant accumulation of fluoride from the
air. No limits are proposed at this time, but it
is recommended that it be placed in a warning
category to be considered as specific cases arise.
Lead: Results from adding lead to nutrient so-
lutions are somewhat contradictory (35, 105).
Toxicities have been reported from additions of
as little as 1 mg/1. But considerably higher levels
have been used in some cases without injury. Since
even sandy soils can be expected to adsorb lead,
the tolerance limit of 5 mg/1 is proposed.
Lithium: Crops sensitive to sodium are also
sensitive to lithium. Most crops can tolerate 5
mg/1 and this limit is proposed for water to be
used on type 'a' lands (18, 20). The same limit
is proposed for water to be used on type 'b' lands,
since it might be expected that a steady state
will be approached within a period of years on
most soils.
Manganese: Manganese toxicities have been ob-
served down to 0.5 mg/1, but a great deal af varia-
tion occurs among species and conditions of nu-
trient imbalance. With suitable management prac-
tices, it should be possible to tolerate up to 2 mg/1
for nearly all species of plants.
Molybdenum: Molybdenum presents a particu-
larly unique problem in that ground waters fre-
quently carry levels of the element that give rise
to plant concentrations toxic to cattle. In nutrient
solution and soil solution measurements, 0.01
mg/1 molybdenum in solution will produce leg-
umes containing in order of 5 mg/kg molyb-
denum or more in the tissue (82). This level is
commonly accepted as the upper limit for safe
feeding to cattle and is, therefore, proposed as the
tolerance limit, even though levels of 0.001 to
0.002 mg/1 molybdenum in river waters are not
uncommon; and the Colorado River at Yuma,
Ariz., is reported at 0.0069 (44).
An upper limit of 0.05 mg/1 is proposed when
the irrigation water is added to acid soils with
a large capacity to combine with the element.
The reason for this action is to protect against
the possibility of inducing molybdenum toxicity
at a later date as a result of overtiming in humid
and subhumid areas.
Nickel: Nickel toxicities occur in nature in con-
junction with high levels of chromium in soils
developed from serpentine rock. These soils may
contain 400 to 5,000 mg/kg, compared with
about 5 to 100 for most soils (35). Surprisingly,
when the occurrence of serpentine-derived soils
is considered, few results are available relating
nickel toxicity to solution concentrations. Growth
of flax is depressed by the presence of 0.5 mg/1
nickel and this value is suggested here for a tenta-
tive tolerance limit. Examination of more sensitive
crops may suggest a lower value.
Selenium: Tolerance limits for selenium should
be based on animal toxicities, rather than those
of plants. Plants containing 4 to 5 mg/kg sele-
nium are commonly considered to induce toxic
symptoms in animals. From results of Broyer
(28), this level of selenium could result in many
species from a level of 0.05 mg/1 selenium in
solution. Tolerance limits will, therefore, be placed
at this value. The assumption is made that there
will be sufficient management of irrigated lands
so that selenium-accumulating plants will not be
a factor. Fertilizer trials in greenhouse experi-
ments indicate that the same limit might best be
applied to water used on type 'b' lands as well.
Tin, Tungsten, and Titanium: Tin, tungsten,
and titanium are effectively excluded by plants.
The first two can undoubtedly be introduced to
plants under conditions that will produce specific
toxicities, but not enough is known about any of
the three to prescribe tolerance limits at this time.
Titanium is too insoluble to be of great concern.
Tungsten has been observed to interfere with
ascorbic acid metabolism in animals (162 ).
Vanadium: Vanadium toxicities have been in-
duced in several plant species in concentrations in
the neighborhood of 10 mg/1 of the vanadate
154
-------
ion (JOS). Since this represents additions of
about 100 pounds per acre of vanadium per year
for 40 inches of irrigation, no increased level of
vanadium for water use on type 'b' lands is pro-
posed.
Zinc: Zinc has produced toxic symptoms in
various plants in concentrations from 3 to 10 mg/1
(35, 105). A tolerance limit of 5 mg/1 is pro-
posed here, since zinc is bound strongly to even
coarse-textured soils. A limit of 10 mg/1 is sug-
gested even for water used on type 'b' land until
evidence is presented to indicate that larger addi-
tions are acceptable. At irrigation additions of
40 inches per year, this would introduce about
100 pounds of zinc per acre per year.
Other Considerations
Acidity and alkalinity and common elements,
including chlorides and bicarbonates, are discussed
here only as they relate to irrigation water in gen-
eral. Specific quality characteristics relating to
arid region irrigation agriculture, or to water for
supplemental irrigation in humid regions, will be
discussed later. No attempt will be made to assign
criteria to each, but appropriate guidelines and
extent of importance will be described.
Acidity and Alkalinity in normal irrigation
water, as measured by pH, have little direct sig-
nificance. Since water itself is unbuffered, and the
soil is a buffered system (except for extremely
sandy soils low in organic matter), the pH of the
soil will not be significantly affected by application
of irrigation water. There are, however, some ex-
tremes and indirect effects.
Water having pH values below 4.8 applied to
acid soils over a period of time may possibly render
soluble iron, aluminum, or manganese in concen-
trations large enough to be toxic to plant growth.
Similarly, addition of a neutral or acid irrigation
water high in salts to an acid soil could result in a
decrease in soil pH, thereby rendering these ele-
ments soluble. In some areas where acid mine
drainage contaminates water sources, pH values
as low as 1.8 have been reported. Waters having
unusually low pH values such as this would be
strongly suspect of containing toxic quantities of
certain heavy metals or other elements.
Water having pH values in excess of 8.3 are
highly alkaline and may contain high concentra-
tions of sodium, carbonates, and bicarbonates.
These constituents affect soils and plant growth
directly or indirectly and these effects will be dis-
cussed later under specific ions.
Since most of the effects of acidity and alkalinity
in irrigation waters are indirect as they relate to
soils and plant growth, it is not practical to set
narrow limits. Water having pH values in the
range of 4.5 to 9.0 should not present any insur-
mountable problems assuming that no indirect
limitations develop resulting from its use.
An imbalance of common nutrient elements can
create an unfavorable environment for plant
growth. Among the common ions which are essen-
tial for plant growth in relatively large quantities,
there is a wide variation in their effect upon spe-
cific crops according to their total and relative
concentrations. Essential ions such as calcium,
magnesium, potassium, and sulfate may deter
growth if the total or relative concentrations are
out of balance. Plants vary in their tolerance of
high concentrations of calcium in the soil solution.
Masaewa (103) found that both calcium chloride
and calcium nitrate were more toxic to soil cul-
tures of flax than added sodium chloride. Wad-
leigh and Gauch (184), however, found some spe-
cies such as guayule to be more tolerant of added
calcium salts than of other neutral salts. Although
harmful concentrations of calcium are rare, this
illustrates a potentially unfavorable effect of one
of the most beneficial ions. Magnesium is fre-
quently more toxic than other elements at the same
osmotic concentration and potassium may have
effects similar to those of magnesium which may
be alleviated by the presence of high calcium con-
centrations in the substrate. Sulfate has specific
deleterious effects on many crops and has been
found to limit calcium uptake. Sodium, which is
very common in saline waters, affects irrigated
crops in many ways. In addition to its effect on
soil structure and permeability, sodium has been
found by Lilleland, et al. (90) and Ayers (8) to
be absorbed by plants and cause leaf burn in
almonds, avocados, and in stone fruits grown in
culture solutions. Bernstein (16) has indicated
that water having SAR 1 values of 4 to 8 may
injure sodium-sensitive plants. It is difficult to
separate the specific toxic effects of sodium from
the effect of absorbed sodium on soil structure.
This latter factor will be discussed later. The
complex interactions of the total and relative con-
centrations of these common ions upon various
crops preclude their consideration as individual
components for general irrigation use, except for
sodium and possibly chlorides in areas where fruit
would be important.
Chlorides are not generally phytotoxic to most
crops. For this reason, no limits should be estab-
lished because detrimental effects from salinity
per se ordinarily deter crop growth first.
1 SAR: Sodium Adsorption Ratio =
pressed as me//.
Na+
. —ex-
. /Ca" + Mg"
V 2
155
-------
Certain fruit crops are, however, sensitive to
chlorides. Bernstein (16) has indicated (table IV-
17) that maximum permissible chloride contents
in the soil solution range from 10 to 50 me/1 for
TABLE IV-17. Maximum Permissible Chloride
Contents in Soil Solution for Various
Fruit-Crop Varieties and Rootstocks (16)
Crop
Rootstock or variety
Limit of
tolerance to
chloride in soil
solution me/I
ROOTSTOCKS
Citrus Rangpur lime, Cleopatra 50
mandarin
Rough lemon, tangelo, sour_ 30
orange
Sweet orange, citrange 20
Stone fruit Marianna 50
Lovell, Shalil 20
Yunnan 14
Avocado West Indian 16
Mexican 10
VARIETIES
Grape Thompson seedless, Perlette 50
Cardinal, Black Rose 20
Berries Boysenberry 20
Olallie blackberry 20
Indian summer raspberry 10
Strawberry ___Lassen 16
Shasta 10
certain sensitive fruit crops. In terms of permissible
chloride concentrations in irrigation water, values
up to 20 me/1 may be used, depending upon en-
vironmental conditions, crops, and irrigation man-
agement practices.
Foliar absorption of chlorides can be of impor-
tance in sprinkler irrigation (48, 50). The adverse
effects vary between day and night (varying
evaporative conditions) and the amount of evapo-
ration that can occur between successive wettings;
i.e., time after each pass with a slowly revolving
sprinkler. There is less effect with nighttime sprin-
kling and less effect with fixed sprinklers (applying
water at a rapid rate) as contrasted with slowly
revolving sprinklers (required to apply water at a
low rate). Concentrations as low as 3 me/1 of
chloride^in the irrigation water have been found
harmful when used on citrus, stone fruits, and
almonds (16).
High Bicarbonate water may induce iron chlo-
rosis by making the iron unavailable to plants
(26). Problems have been noted with apples and
pears (134) and with some ornamentals (98). Al-
though concentrations of 10 to 20 me/1 of bicar-
bonate will cause chlorosis in some plants, it is of
little concern in the field where precipitation of
calcium carbonate minimizes this hazard. It is
difficult to set up specific criteria for such indirect
effects.
Pesticides: Insecticides, fungicides, rodenti-
cides, and herbicides, as a group, include both
organic and inorganic compounds, all of which
can directly or indirectly have a bearing upon the
irrigation water in which they are found. The
effects of some of these can be detrimental to
crops, livestock, wildlife, and man. Some are easily
broken down and disappear quickly while others
are persistent. Some are only sparingly soluble in
water, but all cause problems if accidental spillage
produces high concentrations in water or if they
become adsorbed on colloidal particles subse-
quently dispersed in water.
Compounds derived from petroleum are used
directly for pest control or are involved in formu-
lation and synthesizing other pesticides. Many of
these substances produce no serious pollution haz-
ards because they break down rapidly. Synthetic
materials developed within the last 20 years pro-
duce most of the hazard potential. There are sev-
eral types such as halogenated hydrocarbons,
organophosphates, carbamates, phenoxys, thio-
cyanates, substituted ureas, and triazines. Many
of the halogenated hydrocarbons appear to be
quite persistent in the environment. Aldrin and
dieldrin, chlorinated hydrocarbon insecticides,
have been found to be absorbed by vegetable crops
from contaminated soil. DDT, a widely used in-
secticide for many years, has been found to be very
persistent and can be transported in runoff from
agricultural areas as well as being transported by
air currents (193).
Herbicides are used widely in agriculture di-
rectly on the crop and on the soil, on cropped and
noncrop areas in the vicinity of agricultural areas,
and for aquatic weed control. Petroleum solvents
are effective aquatic weed killers which are rapidly
dissipated and degraded. These aromatic solvents
are widely used for keeping irrigation canals clear
of weeds and are not harmful to crops (29).
Copper sulfate is also widely used in irrigation for
algae and other aquatic weed control. The copper
concentration is maintained at a low level and has
little or no history of producing harmful effects on
crops. The fate of copper applied for weed control
in irrigation canals is being studied in cooperative
aquatic weed research programs by the U.S.
Bureau of Reclamation and Agricultural Research
Service.
156
-------
The phenoxy acid herbicides 2,4-D and 2,4,5-T
have become suspect as contaminants of irrigation
water. Some research has been initiated by various
groups. These materials are known to be subject to
rapid biological degradation in soils, but their fate
in irrigation water and runoff water is still not well
understood. Recent findings indicate that water
temperature and dissolved oxygen content may
influence the rate of biological decomposition of
these herbicides in impounded water (40).
Millions of acres of farm, range, and forest lands
are treated annually with millions of pounds of
pesticides. It has been predicted that present use
of pesticides will increase tenfold in the next 20
years. There is too little known about the ultimate
fate of the many compounds and their influence on
irrigated agriculture as well as the total environ-
ment. This stresses the need for further work to
determine the potential effect of the many pesti-
cides in irrigation water. Some work is currently
underway by industry, universities, and Federal
agencies to study the fate of these pesticides in
irrigated agriculture; but as yet the state of science
is very incomplete.
There is little evidence to indicate that under
normal use insecticide contamination of irrigation
water would be detrimental to plant growth or
accumulate in or on plants in toxic concentrations.
Herbicides, on the other hand, could be harmful
to crop growth if misused. Since many herbicides
break down in water, permissible limits should be
established for the point of application to crops.
Suggested permissible levels are shown in table
IV—18 along with information on treatment rates
of application and estimated concentrations in
water reaching the field or crop. These levels are
tentative and subject to change as indicated by
future research.
Temperature: Excessively high or low tempera-
tures in irrigation water can deter plant growth. It
is not the temperature of the water per se that
affects plant growth, but the resultant temperature
of soil to which it is applied. Numerous investiga-
tions have been carried out relating the tempera-
ture of the substrate to plant growth; but few,
regarding the direct effects of irrigation water tem-
perature. Adverse soil temperature conditions can
affect seedling emergence, growth rate, time of
maturity, and yields of various crops. Here again,
the effect on the plant is governed by specific soil
characteristics and the genetic characteristics of
specific plants. Furthermore, the temperature of
the root zone and effects are governed by tempera-
ture changes occurring between irrigations.
In greenhouse studies with the Calora variety
of rice, Raney (138) allowed the soil solution
temperature to drop from 70 to 50 F for a period
of 4 days. He found that if this were done in the
stage between emergence and tillering, or 30 to
60 days after planting, the yield was depressed by
approximately 10 percent. He also found a com-
parable critical period durihg the flowering period,
about 100 days after planting.
Other water temperature effects were noted by
Wieringa (194) on kidney beans. In greenhouse
experiments, he found that yields would increase
with soil temperature increasing from 70 to 86 F.
With temperatures of 50 F, no germination oc-
curred. By decreasing the temperature from 77 to
50 F for a period of 3 days, a 17-percent decrease
in root and foliar growth occurred if the tempera-
ture decrease was made at the three-leaf stage. The
same process produced a 40-percent decrease in
root and foliar growth at the six-leaf stage and the
yield itself decreased 15 percent when the process
was carried out at the nine-leaf stage.
In regard to tomatoes, Martin and Wilcox
(102) in greenhouse studies found minimum tem-
peratures for satisfactory growth at 56 to 58 F.
Increasing temperatures produced increased yields.
Holekamp and others (69) studied the effects
of water temperatures upon cotton in the green-
house. For emergence, best results were obtained
in the 60 to 70 F range. With temperatures less
than 60 F average minimum soil temperature, only
40 percent of the plantings produced seedlings.
They concluded that there was a 1.7-percent de-
crease in percentage of emergence for each degree
less than the 60 F average minimum.
The adverse effects of cold water on the
growth of rice were suddenly brought to the atten-
tion of rice growers when cold water was first re-
leased from Shasta Reservoir in California (138).
Summer water temperatures were suddenly
dropped from about 61 F down to 45 F. Research
is still proceeding and some of the available in-
formation was recently reviewed by Raney and
Mihara (140). Dams such as the Oroville Dam
are now being planned so that water can be with-
drawn from any reservoir depth to avoid the cold-
water problem. Warming basins have been used
(139). There are opportunities in future planning
to separate waters—the warm waters for recrea-
tion and agriculture; the cold waters for cold-
water fish, salmon spawning, etc.
Review of research accomplishments does not
offer guidelines for establishing temperature cri-
teria for irrigation waters. Aside from the other
complicating variables previously mentioned, the
manner in which irrigation water is applied, sur-
face or sprinkler, could influence changes in the
resultant soil temperature. Assuming that the soil
157
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temperature would not be lowered beyond that
of a cold irrigation water, nor raised above that of
a warm irrigation water, a desirable range of tem-
peratures would be from 55 to 85 F.
Effect on plant quality
There are certain water quality considerations
which are not directly concerned with plant
growth per se. They are significant, however, in
that they adversely affect the quality of the plant
for its intended use. For example, water may carry
microorganisms either directly pathogenic to the
plant, or to animals or humans consuming these
plants. Water may contain a material which is not
toxic to plant growth, but may be absorbed by
and accumulate in plants at levels which may be
toxic to animals or humans which consume them.
Finally, there are materials such as sediment which
affect the appearance and, hence, the marketability
of the crop.
Microorganisms, Pathogenic to Plants,
Animals or Humans
In general, the danger of spread of plant patho-
gens in irrigation water is so slight that it is usually
ignored. Some plant pathogens, however, can sur-
vive and be transported in irrigation water. In
irrigated areas where runoff water from infected
cultivated fields is used again downstream for ir-
rigation, there is definite probability that disease
organisms will be spread from one field to another.
The importance of this is uncertain compared to
other means of spread such as dust storms, farm-
to-farm movement of farm equipment, or direct
wind transport of spores.
Faulkner and Bolander (54)' confirm that large
numbers of nematodes, including plant parasites,
are transported in irrigation water. No attempt has
been made to ascertain the economic importance
of nematodes distributed by water. However, there
is little doubt that irrigation water could be a sig-
nificant source of nematode infestations. Data indi-
cate that each time an acre of land in the Lower
Yakima Valley is irrigated, it may receive from
approximately 4 million to over 10 million plant
parasitic nematodes.
The most likely situation to cause trouble is
where the contaminated water is used for over-
head sprinkling. Some bacterial diseases, and dis-
eases caused by the so-called watermold group of
fungi, may be increased by this practice. Root dis-
ease organisms in general can probably be intro-
duced into clean soils this way also. Recommenda-
tions have been made in the tobacco growing
areas, where the wildfire disease is a problem, that
drainage water from infected tobacco fields not be
used to irrigate other fields. Also, fruit growers are
advised to avoid using drainage water for sprinkler
irrigation in orchards (109).
Lack of efforts to control or eliminate plant dis-
ease organisms in irrigation water is partly due to
the difficulty of doing anything effective about
them. Usually, any plant disease control based on
sanitation is limited to the easiest or least expensive
procedures because, at best, they are only a partial
answer. The disease organisms are microscopic
and cannot be screened from water like weed seeds.
Chemical treatment of the water is expensive and
has many undesirable consequences.
Water may be assayed for plant pathogens; but
there are thousands, or perhaps millions of harm-
less microorganisms for every one that causes a
plant disease. While such selective bioassays are
valuable in research, they are not practical for
monitoring.
If plant disease organisms are to be included in
water quality criteria, they should be framed in
terms of preventive measures rather than by any
assay procedure. For example, dumping of plant
material, which could be diseased, into lakes,
streams, or irrigation systems should be prohibited.
Water used in washing of fresh produce, such as
potatoes, may have to be treated before return to
water supplies that will be used to irrigate crops. It
is also desirable to prevent storage of irrigation
water in a quarantined area for downstream use.
Pests such as the soybean cyst nematode or other
plant nematodes could easily be spread in this way.
Plant infection is not considered serious unless
an economically important percentage of the crop
is affected. The real danger is that a trace of plant
disease can be spread by water to an uninfected
area where it can then spread by other means and
become important. It is unlikely that any method
of water examination would be as effective in pre-
venting this as would be prohibitions such as those
suggested above.
Many microorganisms, pathogenic for either
animals or humans, or both, may be carried in ir-
rigation water, particularly that derived from sur-
face sources. The list comprises a large variety of
bacteria, spirochetes, protozoa, helminths, and
viruses, which find their way into the irrigation
water from municipal and industrial wastes, in-
cluding food-processing plants, slaughterhouses,
poultry-processing operations, and feedlots. The
diseases associated with these organisms include
bacillary and amebic dysentery, Salmonella gastro-
160
-------
enteritis, typhoid and paratyphoid fevers, leptospi-
rosis, cholera, vibriosis, and infectious hepatitis.
Other infections less commonly seen, at least in
the United States, are tuberculosis, brucellosis, lis-
teriosis, coccidiosis, swine erysipelas, ascariasis,
cysticercosis and tapeworm disease, fascioliasis,
and schistosomiasis. Isolation of the pathogens
themselves is far too slow and costly to consider
other than for research purposes and correlation.
Of the types of irrigation commonly practiced,
sprinkling undoubtedly requires the best quality of
water from a microbiological point of view, as the
water and organisms are frequently applied directly
to that portion of the plant above the ground, and
especially for fruits and leafy crops such as straw-
berries, lettuce, cabbage, alfalfa, clover, etc.,
which may be consumed raw. Flooding the field
may pose the same microbiological problems if the
crop is eaten without thorough cooking. Subirriga-
tion and furrow irrigation present fewer problems
as the water rarely reaches the upper portions of
the plant; and root crops, as well as normal leafy
crops and fruits, ordinarily do not permit penetra-
tion of the animal and human pathogens to the in-
side of the plant. Criteria for these latter types may
also depend upon the characteristics of the soil,
climate, and other variables which affect the sur-
vival of the microorganisms.
Benefits can be obtained by coordinated opera-
tion of reservoir releases with downstream inflows
to provide sedimentation and dilution factors to
reduce markedly the concentrations of pathogens
in the water applied in irrigation (31, 84).
Tanner (163) and Rudolfs, Falk, and Ragotzkie
(146) have reviewed the literature on the occur-
rence and survival of pathogenic and nonpatho-
genic enteric bacteria in soil, water, sewage, and
sludges, and on vegetation irrigated or fertilized
with these materials. It would appear from these
reviews that fruits and vegetables growing in in-
fected soil can become contaminated with patho-
genic bacteria and that these bacteria may survive
for periods of a few days to several weeks or more
in the soil and on vegetation.
Falk (53) and Rudolfs, Falk, and Ragotzkie
(144) studied the relative incidence of coliform
organisms on tomatoes grown on three plots of
ground: one plot irrigated with settled sewage con-
currently with growth, one irrigated previous to
planting but not further, and one with no previous
or concurrent irrigation. Except for the tomatoes
wth abnormal stem ends, there was no material
difference in coliform counts per gram of tomatoes
from the three plots. These same authors further
found that Salmonella cerro and Shigella alkales-
cens organisms sprayed on growing tomatoes dis-
appeared within 2 to 7 days, whereas organisms of
the coliform group remained for considerably
longer periods.
Norman and Kabler (121) made coliform and
other bacterial counts in samples of sewage-con-
taminated river and ditch waters and of soil and
vegetable samples in the fields to which these
waters were applied. They found that although the
bacterial contents of both river and ditch waters
were very high, both soil and vegetable washings
had much lower counts. For example, where irri-
gation water had coliform counts of 230,000/100
ml, leafy vegetables had counts of 39,000/100
grams and smooth vegetables, such as tomatoes
and peppers, only 1,000/100 grams. High entero-
coccus counts accompanied high coliform counts
in water samples, but enterococcus counts did not
appear to be correlated in any way with coliform
counts in soil and vegetable washings.
Dunlop and Wang (43) have also endeavored
to study the problem under actual field conditions
in Colorado. Salmonella, Ascaris ova and Enta-
moeba coli cysts were recovered from more than
50 percent of irrigation water samples contami-
nated with either raw sewage or primary-treated,
chlorinated effluents. Only one of 97 samples of
vegetables irrigated with this water yielded Sal-
monella, but Ascaris ova were recovered from two
of 34 of the vegetable samples. Although cysts of
the human pathogen, Entamoeba histolytica, were
not recovered in this work, probably due to a low
carrier rate in Colorado, their similar resistance to
the environment would suggest that these orga-
nisms would also survive in irrigation water for a
considerable period of time. It should be pointed
out, however, that this work was done entirely
with furrow irrigation on a sandy soil in a semiarid
region, and the low recoveries from vegetables
cannot necessarily be applied to other regions or
to sprinkler irrigation of similar crops. In fact,
Miiller (116) has reported that two places near
Hamburg, Germany, where sprinkler irrigation
was used, Salmonella organisms were isolated 40
days after sprinkling on soil and on potatoes, 10
days on carrots, and 5 days on cabbage and
gooseberries.
Miiller (117) has also reported that 69 of 204
grass samples receiving raw sewage by sprinkling
were positive for organisms of the typhoid-paraty-
phoid group (Salmonella). The bacteria began to
die off 3 weeks after sewage application; but 6
weeks after application, 5 percent of the samples
were still infected. These findings emphasize the
importance of having good quality water for
sprinkler irrigation.
161
-------
Tubercle bacilli have apparently not been
looked for on irrigated crops in the United States.
However, Sepp (154) states that several investiga-
tions on tuberculosis infection of cattle pasturing
on sewage-irrigated land have been carried out in
Germany. The investigators are in general agree-
ment that if sewage application is stopped 14 days
before pasturing, there is no danger that the cattle
will contract bovine tuberculosis through grazing.
In contrast, Dedie (39) has reported that these
organisms can remain infective for 3 months in
waste waters, and up to 6 months in soil. The
recent findings of atypical mycobacteria in intes-
tinal lesions of cattle with concurrent tuberculin
sensitivity in the United States may possibly be
due to ingestion of these organisms either from
soil or irrigated pastures.
Both animals and human beings are subject to
helminth infections—ascariasis, fascioliasis, cysti-
cercosis and tapeworm infection, and schistosomia-
sis—all of which may be transmitted through sur-
face irrigation water and plants infected with the
ova or intermediate forms of the organisms. The
ova and parasitic worms are quite resistant to sew-
age treatment processes (187) as well as to chlori-
nation (22) and have been studied quite exten-
sively in the application of sewage and irrigation
water to various crops (125, 153, 187).
The common liver fluke, Fasciola hepatica, the
ova of which are spread from the feces of many
animals, affects cattle and sheep (2, 169, 171)
commonly, in the United States, and man to a
lesser extent. The intermediate hosts, certain spe-
cies of snails, live in springs, slow-moving swampy
waters, and on the banks of ponds, streams, and
irrigation ditches. After development in the snail,
the cercarial forms emerge and encyst on grasses,
plants, bark, or soil. Cattle and sheep become in-
fected by ingestion of the grasses and plants, or the
water, in damp or irrigated pastures where vegeta-
tion is infested with metacercariae. Man contracts
the disease by ingesting plants such as watercress
or lettuce containing the encysted metacercariae.
Ascaris ova are also spread from the feces of
infected animals and man and are found in irriga-
tion water (187). Cattle and hogs are commonly
infected, where the adult worms mature in the
intestinal tract, sometimes blocking the bile ducts.
Ascaris ova have been reported to survive for 2
years in irrigated soil and have been found on irri-
gated vegetables even when chlorinated effluent
was used for irrigation (61,145).
Schistosomiasis, although not yet prevalent in
the United States except in immigrants from en-
demic areas, should be considered for the future as
these individuals move about the country into irri-
gated areas. The life cycle of these schistosomes is
similar to that of the liver fluke in that eggs from
the feces or urine of infected individuals are
spread from domestic wastes and may reach sur-
face irrigation waters where the miracidial forms
enter certain snails and multiply, releasing fork-
tailed cercariae. Although these cercariae may pro-
duce disease in man if ingested, the more common
method of infection is through the skin of indi-
viduals working in the infested streams and irriga-
tion ditches. Such infections are most common in
Egypt (10) and other irrigated areas where work-
ers wade in the water without boots. It is unlikely
that the cercariae would survive long on plants
after harvest.
Little is known of the possibility that enteric
viruses such as polioviruses, Coxsackie, ECHO,
and infectious hepatitis viruses may be spread
through irrigation practices. Murphy and his co-
workers (118) tested the survival of polioviruses
in the root environment of tomato and pea plants
in modified hydroponic culture. In a second paper,
Murphy and Syverton (119) studied the recovery
and distribution of a variety of viruses in growing
plants. The authors conclude that it is unlikely
that plants or plant fruits serve as a reservoir and/
or carrier of poliovirus. However, their findings of
significant absorption of a mammalian virus in the
roots of the plants suggest that more research is
needed in this area.
Many other microorganisms than those specifi-
cally mentioned in this section may be transmitted
to plants, animals, and human beings through irri-
gation practices. One of the more serious of these
is vibriosis. In some cases, definitive information
on other microorganisms is lacking. In others,
such as the cholera organisms, while their signifi-
cance in other parts of the world is well estab-
lished, they are no longer important in the United
States.
Direct search for the presence of pathogenic
microorganisms in streams, reservoirs, irrigation
water, or on irrigated plants is too slow and cum-
bersome for routine control or assessment of
quality. Instead, accepted index organisms such as
the coliform group and fecal coli (74), which are
usually far more numerous from these sources,
and other biological or chemical tests, are used to
assess the quality of the water.1 Two extensive in-
1 For a more complete discussion, see Geldreich, E. E.
1966. Sanitary significance of fecal coliforms in the
environment. U.S. Department of the Interior. FWPCA.
Pub. WP-20-3.
162
-------
vestigations of stream basins (178, 180) have
demonstrated the value of these criteria in assessing
the quality of raw water. Maintenance of quality
within these recommendations should insure suffi-
ciently low concentrations of pathogenic micro-
organisms that no hazard to animals or man should
result from the use of the water on even those crops
which are consumed raw.
In the study of the Red River of the North,
North Dakota-Minnesota (178), Salmonella were
not recovered from a reference point upstream
from the Fargo and Moorhead municipal treatment
plants and from a sugar company plant at Moor-
head. Total and fecal coliforms at this upstream
reference point were 500/100 ml and 100/100
ml, respectively. Salmonella were recovered in the
three sources of waste and in the river below the
discharges, the river samples showing 75,000 coli-
forms/100 ml and 15,500 fecal coli/100 ml. It is
suggested in that report that the stream should be
maintained at not more than 5,000 coliforms/100
ml even at critical periods of riverflow. Such a
standard could be maintained by secondary treat-
ment plus disinfection of the waste sources.
In a similar, but more extensive, study of the
South Platte River Basin in Colorado (180), Sal-
monella recoveries have not yet been reported, but
maximum total coliforms of 5,000/100 ml and
maximum fecal coli of 1,000/100 ml were recom-
mended. In this study also, attention was given to
dissolved oxygen (DO) and 5-day, 20 C BOD
levels. Minimum levels of 4 mg/1 DO and a maxi-
mum of 20 mg/1, 5-day 20 C BOD levels were also
recommended for water used primarily for irriga-
tion. These criteria likewise are consistent with
quality that can be maintained by secondary treat-
ment plus disinfection of all waste sources.
Toxicity to Animals or Humans Through
Accumulation in Plants
Selenium is an example of an element which
may occur in soUs in trace amounts, yet which may
be accumulated in certain cereals and pasture
plants without apparent injury, but in quantities
harmful to animals or humans when consumed.
Deficiencies of this element in animal diets may
result in white muscle disease, but an excess pro-
duces conditions known as "alkali disease" and
"blind staggers." Trelease and Beath (167) have
noted that selenium absorbed by grasses and ce-
reals enter the food chain of animals and humans.
Molybdenum is another example of an element
which can accumulate in plants and become detri-
mental to livestock.
There is no evidence to date to indicate that
selenium or molybdenum occurrence in natural ir-
rigation water is a significant factor. It is important
to point out, however, that pollution of irrigation
waters by industrial sources could introduce harm-
ful concentrations of these and other elements.
Suspended Solids: Suspended solids in irrigation
water can affect plant growth and quality in sev-
eral ways. Deposition of colloidal particles on the
soil surface can produce crusts which inhibit water
infiltration and seedling emergence. This same de-
position and crusting can reduce soil aeration to a
level where it impedes plant development. High
colloidal content in water used for sprinkler irriga-
tion could result in deposition of films on leaf sur-
faces which could reduce photosynthetic activity
and thereby deter growth. Where sprinkler irriga-
tion is used for leafy vegetable crops such as let-
tuce, sediment may accumulate on the growing
plant, affecting the marketability of these products.
Radionuclides: There are no generally accepted
standards for control of radioactive contamination
in irrigation water. For most radionuclides, the
use of USPHS Drinking Water Standards (775)
appear to be reasonable for irrigation water. Sup-
plies containing not in excess of 3 and 10 pc/1,
respectively for radium-226 and strontium-90
would be acceptable without consideration of other
radioactive sources. In the known absence of
strontium-90 and alpha-emitting radionuclides, the
water supply is considered acceptable if the gross
beta activity does not exceed 1,000 pc/1. If the
gross beta activity is in excess of this amount, a
more complete radiochemical analysis is required
to determine that the sources of radiation exposure
are within the limits of the Radiation Protection
Guides. One state, Washington, has proposed such
a standard for irrigation water (188).
The limiting factor for radioactive contamina-
tion in irrigation is its transfer to foods and even-
tual intake by humans. Such a level of contamina-
tion would be reached long before any damage to
plants themselves could be observed. Plants can
absorb radionuclides in irrigation water in two
ways: direct contamination of foliage through
sprinkler irrigation, and indirectly through soil con-
tamination. The latter presents many complex
problems since eventual concentration in the soil
will depend on the rate of water application, the
rate of radioactive decay, and other losses of the
radionuclide from the soil. Some studies relating to
these factors have been reported (96, 107, 108,
112, 114,127).
Calculations, using the drinking water standards
listed above, indicate that irrigation water having
163
-------
the maximum permissible concentrations of stron-
tium-90 and radium-226 would be permissible for
at least nine and 40 years, respectively, before det-
rimental effects would be noted.
Impairment of soil quality
Sodium Hazard
Sodium in irrigation water may become a prob-
lem in the soil solution as a component of total
salinity increasing the osmotic concentration, and
as a specific source of injury to fruits. It is mainly
a problem, however, due to its effect on soil struc-
ture, infiltration, and permeability rates. Since good
drainage is essential for management of salinity in
irrigation, and for reclamation of saline lands, good
soil structure and permeability must be main-
tained. A high percentage of exchangeable sodium
in a soil containing swelling-type clays results in a
dispersed condition unfavorable for water move-
ment and plant growth.
The organic and clay fractions of the soil possess
ion exchange properties. These fractions carry pre-
dominantly negative charges and, therefore, ab-
sorb positive ions (cations); predominantly cal-
cium, magnesium, potassium, sodium, hydrogen,
and aluminum. The distribution of adsorbed ca-
tions in the soil is in equilibrium with the soil solu-
tion. Anything that alters the composition of the
soil solution, such as irrigation or fertilization, dis-
turbs the equilibrium and alters the distribution of
adsorbed ions in the soil. When calcium is the pre-
dominant cation adsorbed on this exchange com-
plex, the soil tends to have a granular structure
which is easily worked and readily permeable.
When the amount of adsorbed sodium exceeds 10
to 15 percent of the total cations on the exchange
complex, the clay becomes dispersed and slowly
permeable unless a flocculated condition is main-
tained due to a high concentration of total salts.
Where soils have a high exchangeable sodium con-
tent and are flocculated due to the presence of free
salts in solution, subsequent removal of salts by
leaching will cause sodium dispersal to occur un-
less leaching is accomplished using additions of
calcium or calcium-producing amendments.
Adsorption of sodium from a given irrigation
water is a function of the proportion of sodium to
divalent cations (calcium and magnesium) in that
water. To estimate the degree to which sodium will
be adsorbed by a soil from a given water when
brought into equilibrium with it, the U.S. Salinity
Laboratory (181) proposed the sodium adsorption
ratio (SAR); see footnote, page 155. As soils tend
to dry, the SAR value of the soil solution increases
even though the relative concentrations of the
cations remain the same. This is apparent from
the above equation where the denominator is a
square-root function. This is a significant factor in
estimating sodium effects on soils.
The SAR value can be related to the amount of
exchangeable sodium in the soil expressed as a
percentage of the total exchangeable cation con-
tent. This latter value is called the exchangeable
sodium percentage (ESP). From empirical deter-
minations, the U.S. Salinity Laboratory obtained
an equation for predicting a soil ESP value based
on the SAR value of a water in equilibrium with it.
This is expressed as follows:
100 [a+b(SAR)]
l + [a+b(SAR)]
The constants "a" (intercept representing experi-
mental error) and "b" (slope of the regression
line) were determined statistically by various in-
vestigators who found "a" to be in the order of
— 0.06 to 0.01 and "b" to be within the range of
0.014 to 0.016. Thus, ESP as calculated from SAR
value will normally have a value slightly higher
than the SAR. This relationship is shown in the
nomogram [fig. IV-4 developed by the U.S. Salin-
ity Laboratory (181)]. For sensitive fruits, the
tolerance limit for SAR of irrigation water is about
4. For general crops, a limit of 8 to 1 8 is generally
considered within a usable range although this
depends to some degree on the type of clay min-
eral, electrolyte concentration in the water, and
other variables.
The ESP value that significantly affects soil
properties varies according to the proportion of
swelling and nonswelling clay minerals. An ESP of
10 to 15 percent is considered excessive if a high
percentage of swelling clay minerals such as mont-
morillonite is present. Fair crop growth of alfalfa,
cotton, and even olives, have been observed in
soils of the San Joaquin Valley with ESP values
ranging from 60 to 70 percent (148). This condi-
tion is being studied further and is apparently the
result of a high percentage of nonswelling clay
minerals.
Prediction of the equilibrium ESP from SAR
values of irrigation waters is complicated by the
fact that the salt content of irrigation water be-
comes more concentrated in the soil solution. Ac-
cording to the Salinity Laboratory (181), shallow
ground waters 10 times as saline as the irrigation
waters may be found at depths of 10 feet and a salt
concentration two to three times that of irrigation
water may be reasonably expected in the first-foot
164
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- 15
-120
Figure IV-4—Nomogram for determining the SAP value of irrigation water and for estimating
the corresponding ESP value of a soil that is at equilibrium with the water (181)
165
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depth. Under conditions where precipitation of
salts and rainfall may be neglected, the salt con-
tent of irrigation water will increase to higher con-
centrations in the soil solution without change in
relative composition. The SAR increases in pro-
portion to the square root of the concentration;
therefore, the SAR applicable for calculating equi-
librium ESP in the upper root zone may be as-
sumed to be two to three times that of the irriga-
tion water.
Many attempts have been made to predict ca-
tion exchange reactions in soils (45, 51, 80, 181).
Some of these have been used to predict the degree
to which sodium will be adsorbed by a soil from a
water of given quality. Many variables can influ-
ence the cation equilibria attained in the soil. These
include the relative proportions of cations and
anions in the water added and those present in the
soil, the presence of slightly soluble constituents
such as lime and gypsum, clay mineral types pres-
ent, and the salt concentrating action of evapo-
transpiration. For this reason, field studies are
needed to support predictive relations developed
under laboratory conditions.
BOD and Soil Aeration
The need for adequate available oxygen in the
soil for optimum plant growth is well recognized.
To meet the oxygen requirement of the plant, soil
structure (porosity) and soil water contents must
be adequate to permit good aeration. Conditions
that develop immediately following irrigation are
not clearly understood.
Soil aeration and oxygen availability normally
present no problem on well-structured soils with
good quality water. Where drainage is poor, oxy-
gen may become limiting. Utilization of waters
having high BOD or COD values could aggravate
the condition by further depleting available oxygen
and produce reducing conditions in the soil. Aside
from detrimental effects of oxygen deficiency for
plant growth, reduction of elements such as iron
and manganese to the more soluble divalent forms
may create toxic conditions. Other biological and
chemical equilibria .may also be affected.
There is very little information regarding the
effect of using irrigation waters with high BOD
values on plant growth. Between source of con-
tamination and point of irrigation, considerable
reduction in BOD value may result. Sprinkler
irrigation may further reduce the BOD value of
water. Infiltration into well-drained soils can also
decrease the BOD value of the water without
seriously depleting the oxygen available for plant
growth.
Where irrigation is used for disposal of waste
effluents with high BOD, lack of oxygen and
reducing conditions could easily become signifi-
cant factors for plant growth. However, if amounts
of water applied do not greatly exceed crop re-
quirements, it is probable the crop will not be
adversely affected.
Suspended Solids
Large quantities of suspended solids in irrigation
water can affect irrigation in many ways. In sur-
face irrigation, suspended solids can interfere with
the flow of water in conveyance systems and struc-
tures. Deposition of sediment not only reduces the
capacity of these systems to carry and distribute
water, but can also decrease reservoir storage ca-
pacity. For sprinkler irrigation, suspended mineral
solids may cause undue wear on irrigation pumps
and sprinkler nozzles as well as possibly plugging
up the latter, thereby reducing irrigation efficiency.
Soils are specifically affected by deposition of
these suspended solids, especially when they con-
sist primarily of clays or colloidal material. These
cause crust formations which reduce seedling emer-
gence. In addition, these crusts reduce infiltration
thereby reducing irrigation efficiency and hinder-
ing the leaching of saline soils. The scouring action
of sediment in streams has also been found to affect
soils adversely by contributing to the dissolution
and increase of salts in some areas (730).
Conversely, sediment high in silt may improve
the texture, consistence, and water-holding capac-
ity of a sandy soil. An example of this beneficial
effect has occurred by irrigation from the silt-laden
waters of the Virgin River in Southwestern Utah,
where silt loams have been deposited over loamy
sands to depths of 1 foot or more over a period of
many years.
166
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specific irrigation water
quality considerations
for arid
and semiarid regions
must supply one-half to all or most of the soil mois-
ture required for crops for annual periods ranging
from 3 to 12 months.
Annual precipitation varies in the Western
United States from practically zero in the south-
western deserts to in excess of 100 inches in the
upper western slope of the Pacific Northwest. The
distribution of precipitation throughout the year
also varies, with no rainfall during extended pe-
riods in many locales. Often the rainfall occurs
during nongrowing seasons.
The amount of precipitation and its distribution
is one of the principal variables in determining the
diversion requirement, or "demand," for irrigation-
water.
Environmental factors
Climate
Climatic variability exists in arid and semiarid
regions. In the Far West, the Pacific Ocean pro-
vides considerable moderation, preventing ex-
tremely high summer temperatures and extremely
low winter temperatures; this influence de-
creases with distance from the coast and with the
presence or absence of intervening mountains.
There are differences due to altitude, the highest
elevations having the shortest frost-free growing
season, and the lowest elevations having the long-
est. The latitude affects the length of the growing
seasons, permitting subtropical fruits and winter
vegetables, etc., to be grown in the low-elevation
southern portions. Deciduous fruits with a winter
chilling requirement are examples of crops favor-
ing the northern latitudes. There can be heavy
winter precipitation, generally increasing from
south to north, and increasing with elevation.
Summer showers are common, increasing north
and east from California. The only thing common
through this Western part of the country is the
inadequacy of precipitation during the growing
season. In most areas of the West, intensive agri-
culture is not possible without irrigation. Irrigation
Land
Soils of the arid and semiarid regions were de-
veloped under a drier regime than the soils of the
more humid areas. They have more weatherable
minerals and consequently are generally better sup-
plied with the nutrient elements except for nitro-
gen. These soils generally have relatively high ex-
changeable cation status, base status, and a low
degree of acidity. Also, if they have developed pro-
files, the topsoils are not as deep as in the more
humid areas. Because of less frequent passage of
rainfall through the soil profiles, they are shallower
and are more apt to be saline.
For irrigation purposes, soils are sometimes
grouped in accord with their topographic position.
Upland soils are those formed in place by the
weathering of the underlying parent material or to
some extent, from materials moved laterally by
colluvial forces. They are also the soils where the
greatest erosion is usually taking place. Most of the
material eroded and transported downstream as
sediments, largely during floods, is deposited on
the flood plain and deltas. The deep, medium-tex-
tured soils of the flood plains are recognized as the
prime agricultural soils. Farther down the river
system, soils of the basin are normally found.
These basins are regions of flat gradient where
drainage is impeded. They may be swampy, at least
during time of flood, but can be a filled lake or
estuary. The distinctive features are a high water
table and fine-textured materials.
One other soil position should be mentioned—
the terrace. The terrace is created as a flood-plain
alluvium. Because of stream lowering, there is no
longer deposition, but its gradient is flat enough
to limit erosion hazard. Over thousands of years,
the soil can develop a profile. Percolating water
causes the leaching of colloidal material and solu-
ble constituents from the top soil to be deposited
167
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or precipitated out in the subsoil. The subsoil con-
stitutes a horizon below the surface and usually is
of finer texture and more compact. The surface
horizon varies in thickness from a few inches to a
few feet and can provide a good environment for
plant roots if deep enough; but the subsoil often
cannot, and water often does not penetrate it
readily. Soils with restrictive horizons are not the
best for irrigated agriculture; but if in an elevated
position relative to surrounding land, the night air
currents may make them more frost-free and suit-
able for sensitive crops that cannot be grown
elsewhere.
Water
Each river system within the arid and semiarid
portion of the United States has quality character-
istics peculiar to its geologic origin and climatic
environment. In considering water quality charac-
teristics as related to irrigation, both historic and
current data for the stream and location in question
should be used with care because of the large
seasonal and sporadic variations which occur.
Both chemical composition and sediment load
in surface waters will vary with the stage of flow.
Salt concentration during low-flow periods is us-
ually greater than during peak flows. Storm runoff
not only affects the salt content, but frequently
tends to increase the sediment burden. Because of
variations in rainfall distribution, water quality
characteristics will differ significantly. Where rain-
fall is more uniformly distributed, the maximum
concentrations of dissolved solids are two to three
times the minimum, whereas this factor may vary
from 5 to 10 where rainfall distribution is more
sporadic.
The range of sediment concentrations of a river
throughout the year usually is much greater than
the range of dissolved solids concentrations. Maxi-
mum concentrations may be 10 to more than a
thousand times the minimum concentrations. Usu-
ally the sediment concentrations are higher during
high flow than during low flow. This differs in-
versely from dissolved-solids concentration which
is usually lower during high flows.
Four general designations of water have been
used (136), based on their chemical composition:
calcium-magnesium, carbonate-bicarbonate; cal-
cium-magnesium, sulfate-chloride; sodium-potas-
sium, carbonate-bicarbonate; and sodium-potas-
sium, sulfate-chloride. Although a listing of data
for each stream and tributary is beyond the scope
of this report, an indication of ranges in dissolved-
solids concentrations, chemical type, and sediment
concentration are given in table IV-19 (136).
Customarily, each irrigation project diverts
water at one point in the river and the "return
flow" comes back into the mainstream somewhere
below the system. This return flow consists in the
main of: (1) regulatory water, the unused part of
the diverted water required so that each farmer
irrigating can have the exact flow he has ordered;
(2) tail water, that portion of the water which runs
off the ends of the fields; and (3) underground
drainage, required to provide adequate application
TABLE IV-19. Variations in Dissolved Solids, Chemical Type, and Sediment (136). Rivers in
Arid and Semiarid United States
Region
Dissolved solids
concentrationsr mg/l
From To
Prevalent chemical type '
Sediment concentrations,
mg/l »
From To
Columbia River Basin .. .. .
Northern California
Southern California _ _
Colorado River Basin
Rio Grande Basin, __ _
Pecos River Basin .. .
Western Gulf of Mexico Basins__
Red River Basin _. __
Arkansas River Basin .
Platte River
Upper Missouri River Basin ..
<100
<100
<100
<100
<100
100
100
<100
100
100
100
300
700
+2,000
+2,500
+2,000
+3,000
+3,000
+2,500
+2,000
+ 1,500
+2,000
Ca-Mg, C-b
Ca-Mg, C-b
Ca-Mg, C-b; Ca-Mg, S-C
Ca-Mg, S-C; Ca-Mg, C-b
Ca-Mg, C-b; Ca-Mg, S-C
Ca-Mg, S-C
Ca-Mg, C-b; Ca-Mg, S-C; Na-P,
S-C.
Ca-Mg, S-C; Na-P, S-C
Ca-Mg, S-C; Ca-Mg, C-b; Na-P,
S-C.
Ca-Mg, C-b; Ca-Mg, S-C
Ca-Mg, S-C; Na-P, C-b; Na-P,
C-b.
<200
<200
<200
<200
+300
+300
<200
+300
+300
+300
<200
300
+500
+ 15,000
+ 15,000
+50,000
+7,000
+30,000
+25,000
+30,000
+7,000
+ 15,000
1 Ca-Mg, C-b —Calcium-magnesium, carbonate-bicarbonate.
Ca-Mg, S-C= Calcium-magnesium, sulfate-chlonde.
Na-P, C-b — Sodium-potassium, carbonate-bicarbonate
Na-P, S-C— Sodium-potassium, sulfate-chloride.
2 Sediment concentration =
Annual Load
Annual Strearrrflow
168
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and salt balance in all parts of the fields. The ini-
tial flush of tail water may be somewhat more
saline than later, but rapidly approaches the same
quality as the applied water (141).
In many projects, however, a large part of the
unused water supply does get into the soil, through
seepage from ditches and from amounts entering
the irrigated soil in excess of that utilized in evapo-
transpiration. Such waters that have entered the
soil are more saline and do return to the down-
stream supply by one means or another. It is
axiomatic that water is actually used and reused
numerous times in a river system and there will be
progressive concentration of salts except as the
mainstream is diluted by tributaries.
Drainage and leaching requirement
Addition of irrigation water in excess of that
required for plant use is necessary to prevent salt
accumulation in the soil. This is referred to as the
leaching requirement. It is possible to predict the
approximate salt concentration that would occur
in the soil after a number of irrigations by estimat-
ing the proportion of applied water that will perco-
late below the root zone. In any steady state leach-
ing formula, the following assumptions are made:
(1) No precipitation of salts occurs in the soil;
(2) Ion uptake by plants is negligible;
(3) Uniform distribution of soil moisture
through the profile and uniform concentra-
tion of salts in the soil moisture;
(4) Complete and uniform mixing of irrigation
water with soil moisture before any of the
moisture percolates below the root zone;
and
(5) Residual soil moisture is negligible.
A steady state leaching requirement formula has
been developed by the U.S. Salinity Laboratory
(181) designed to estimate that fraction of the
irrigation water that must be leached through the
root zone to control soil salinity at any specified
level. This is given as:
where LR = leaching requirement;
Ddw=depth of drainage water;
D1W = depth of irrigation water;
EQW = salinity of irrigation water;
ECdw=salinity of water percolating past root
zone.
Hence, if ECaw is determined by the salt toler-
ance of the crop to be grown, and the salt content
of the irrigation water EClw is known, the fraction
can be calculated. This will then determine the
relationship between the depths of irrigation and
drainage water which must be applied. Since ECe
(electrical conductivity of the soil solution extract)
is a diluted index value relative to the actual EC of
the soil water, and since ECdw is the permissible
salt concentration at the bottom of the root zone
with the mean level of soil salinity being consider-
ably less, the ECe value for 50-percent yield reduc-
tion for a particular crop has been recommended
as a guide for ECdw. The actual yield reduction
probably would be less than 50 percent (15).
Bernstein (16) has developed a leaching frac-
tion formula which takes into consideration factors
that control leaching rates such as infiltration rate,
climate (evapotranspiration), frequency and dura-
tion of irrigation, and, of course, the salt tolerance
of the crops. He defines the leaching fraction as
LF= 1 -ETc/ITi where LF= the leaching fraction
or proportion of applied water percolating below
the root zone; E= the average rate of evapotrans-
piration during the irrigation cycle, Tc; and 1= the
average infiltration rate during the period of infil-
tration, TI. By utilizing both the required leaching
derived from the steady-state formula
LR =
EC1W
and the leaching fraction based upon infiltration
rates and evapotranspiration during the irrigation
cycle, it is possible to estimate whether adequate
leaching can be attained or whether adjustments
must be made in the crops to be grown to permit
higher salinity concentrations.
In addition to determination of crops that should
be grown, leaching requirements may be used to
indicate the total quantities of water that will be
required. For example, irrigation water with a
conductivity of 2 millimhos requires one-sixth
more water to maintain root zone salt concentra-
tions within 8 millimhos than would water with a
salt concentration of 1 millimho under the same
conditions of use. In other words, where 600 acre-
feet of less saline water would suffice, 700 acre-
feet of the more saline water would be required to
accomplish the same result.
There are problems with applying the leaching
requirement concept in actual practice. In the first
place, it is not practical to apply water with com-
plete uniformity. In surface irrigation, the objec-
tive is to apply the same amounts of water to all
parts of the field; but particularly in view of the
ever-increasing cost of skilled labor, some parts of
a field may receive more water than others. Gen-
erally, land is not sufficiently leveled to achieve
169
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an even depth of water application. With sprinkler
irrigation, there is a common need, particularly in
the arid and semiarid regions, of keeping applica-
tion rates low. This need is in conflict with attempts
to approach complete uniformity of coverage. Op-
timum sprinkler uniformity of coverage is about
85 percent under still conditions and less with
wind.
Secondly, soils are far from uniform, particularly
with respect to vertical hydraulic conductivity.
Considerable nonuniformity must be expected, far
more in areas of discontinuous stratification than
elsewhere.
Thirdly, the effluent from tile or ditch drains
may not be representative of the salinity of water
at the bottom of the root zones. The streamlines of
flow from the water table to the tile go to consid-
erable depths; and in a newly reclaimed area par-
ticularly, the ground water below the tile system
may be undergoing considerable freshening. Re-
cent studies in the San Joaquin Valley of Califor-
nia indicate that this freshening will go on for 50
years (134).
Fourthly, there is a considerable variation in
drainage outflow which has no relation to leaching
requirement when different crops are irrigated
(131). This results from variations in irrigation
practices for the different crops.
The leaching requirement concept while very
useful should not be used as a sole guide in the
field. The leaching requirement is a long-period
average value which can be departed from for
short periods with adequately drained soils to make
temporary use of water poorer in quality than
customarily applied.
The exact manner in which leaching occurs and
the appropriate values to be used in leaching re-
quirement formulae require further study. The
many variables and assumptions involved preclude
a precise determination under field conditions.
Specific problem areas
Salinity Hazard
Waters with TDS less than about 500 mg/1 are
used by farmers without awareness of any salinity
problem, unless, of course, there is a high water
table (97). Also, without dilution from precipita-
tion or an alternative supply, waters with TDS of
about 5,000 mg/1 usually have little value for irri-
gation (130). Within these limits, the value of the
water appears to decrease as the salinity increases.
Where water is to be used regularly for the irriga-
<0.75
tion of relatively impervious soil, its value is lim-
ited if the TDS is in the range of 2,000 mg/1.
The following classification as to salinity hazard
is suggested:
TDS mg/l EC mmhos/cm
Water for which no detri-
mental effects will usually
be noticed <500
Water which can have det-
rimental effects on sensi-
tive crops 500-1,000 0.75-1.50
Water that may have ad-
verse effects on many
crops and requiring care-
ful management practices. 1,000-2,000 1.50-3.00
Water that can be used for
tolerant plants on perme-
able soils with careful
management practices — 2,000-5,000 3.00-7.50
Permeability Hazard
There are two criteria that are used to evaluate
the effect of certain salts in the irrigation water on
soil permeability. One of these is the sodium ad-
sorption ratio (SAR) and its relation to the ex-
changeable sodium percentage. The other of these
is the bicarbonate hazard which is particularly
applicable to arid region irrigation agriculture.
Eaton (47) developed the concept of "residual
sodium carbonate" (RSC) for characterizing water
quality. More recently, Bower, et al. (23, 24)
found that the hazard is related to the tendency
of calcium carbonate to be precipitated from the
soil solution, as indicated by the Langelier index
(83) and to the fraction of inflow water evapo-
transpired. In other words, the greater the tend-
ency of the soil water to precipitate CaCO3 during
the evapotranspiration concentration process be-
tween irrigations, the more rapidly SAR of that soil
water increases. Thus, there is a relationship be-
tween SAR and bicarbonate hazard, as suggested
by Doneen (41, 42), but any specific relationship
is affected by irrigation management practices. In
general, the bicarbonate hazard presents the great-
est problem at low salt concentrations.
Another problem with a permeability hazard is
that permeability tends to increase and the stability
of a soil to any ESP level increases as the salinity
of the soil water increases (135). The work of
Rollings gives the most recent information on the
interrelationships of EC, SAR, and soil structure
stability (144).
Doneen (41) has long suggested that precipi-
table calcium carbonate and the precipitable cal-
cium sulfate be deducted from total salinity to get
what he calls "effective salinity." Christiansen and
170
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Thorne (37) raise a similar question regarding the
bicarbonates. Waters high in bicarbonate relative
to other anions can affect permeability more than
their SAR would indicate. Coachella Valley of
California was formerly irrigated with well water.
Some well waters low in salt and low in SAR but
relatively high in bicarbonate created highly im-
pervious soils. The problem disappeared upon in-
troduction of Colorado River water, higher in
salts than the well water used, but having a positive
Langelier index—a strong tendency to deposit
calcium carbonate.
In summary, water with SAR values between
eight and 18 may have an adverse effect on per-
meability of soils containing an appreciable
amount of clay. The specific SAR value that has
this effect increases as the salinity increases. Low
salt water high in bicarbonates may present a
permeability hazard even at low SAR values.
specific irrigation water
quality considerations
for humid regions
Suspended Solids
Suspended organic solids in surface water sup-
plies seldom give trouble in ditch distribution sys-
tems except for occasional clogging of gates and
for carrying weed seeds onto fields where subse-
quent growth of weeds can have a severely adverse
effect on the crop, but also may have a beneficial
effect by reducing seepage losses. Where surface
water supplies are distributed through pipelines, it
is often necessary to have self-cleaning screens to
prevent clogging of the pipe system appliances.
Finer screening is usually required where water en-
ters pressure-pipe systems for sprinkler irrigation.
There are waters diverted for irrigation that
carry heavy inorganic sediment loads. The effects
that these loads might have depends in part on the
particle-size distribution of the suspended material.
The ability of sandy soils to store available mois-
ture has been greatly improved after being irri-
gated with muddy water for a period of years.
More commonly, sediment tends to fill canals and
ditches, causing serious cleaning and dredging
problems. It also tends to further reduce the
already low infiltration characteristics of slowly
permeable soils. Kennedy (76) developed criteria
to keep sediments moving in irrigation canals to
prevent deposition. These criteria worked very
well with the somewhat coarser sediments of the
Indus River system where they were developed,
but are not universally adaptable. In most waters
carrying appreciable amounts of sediments, provi-
sion is usually made now for most to be settled out
and be bypassed back to the mainstream near the
point of diversion.
Environmental factors
Climate
The most striking feature of the climate of the
humid region that contrasts with that of the far
West and intermountain areas is the larger amount
of, and less seasonable distribution of, the precipi-
tation. Rainfall, rather than lack of it, is the normal
expectation. There are perhaps more cases in
which crops are damaged because of too much
water than because of too little. Yet, droughts are
common enough to require that attention be given
to supplemental irrigation. These times of shortage
of water for optimum plant growth can occur at
irregular intervals and at almost any stage of plant
growth.
Water demands per week or day are not as high
in humid as in arid lands. But rainfall isn't easily
predicted. Thus a crop may be irrigated and imme-
diately thereafter receive a rain of one or two
inches. Supplying the proper amount of supple-
mental irrigation water at the right time is not easy
even with adequate equipment and a good water
supply. There can be periods of several successive
years when supplemental irrigation is not required
for most crops in the humid area. There are times,
171
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however, when supplemental water can increase
yield or avert a crop failure. Supplemental irriga-
tion for high-value crops will undoubtedly increase
in humid areas in spite of the fact that much capi-
tal is tied up in irrigation equipment during years
in which little or no use is made of it.
The range of temperatures in the humid region
in which supplemental irrigation is an appreciable
factor is almost as great as that mentioned for the
arid and semiarid areas. It ranges from the spe-
cialty crop production in the short growing season
of upstate New York and Michigan to the continu-
ous growing season of southern Florida. But in
the whole of this area, the most unpredictable fac-
tor in crop production is the need for additional
water for optimum crop production.
Soils
The soils of the humid region contrast with
those of the West primarily in being lower in avail-
able nutrients. They are also generally more acid
and may have problems with exchangeable alu-
minum. The texture of soils is similar to that
found in the West and ranges from sands to clays.
Also, some are too permeable while others take
water very slowly.
Soils of the humid region generally have clay
minerals of lower exchange capacity than soils of
the arid and semiarid regions and hence lower
buffer capacity. They are more easily saturated
with anions and cations. This is an important con-
sideration if irrigation with brackish water is nec-
essary to supplement natural rainfall. Organic mat-
ter content ranges from practically none on some
of the Florida sands to the high amounts found in
some irrigated mucks and peats.
One of the most important characteristics of
many of the soils of the humid Southeast is the un-
favorable root environment of the deeper horizons
containing exchangeable aluminum and having a
strong acid reaction. In fact, the lack of root pene-
tration of these horizons by most farm crops is the
primary reason for the need for supplemental irri-
gation during short droughts. If soil and water
management practices would permit roots to pene-
trate another foot or two, many irrigations would
not be needed. Sometimes normally deep-rooted
crops such as alfalfa will wilt or stop growing when
there is plenty of available water at a depth as
shallow as 2 feet.
Though there are some relatively level irrigated
areas in the humid region, as a whole the land-
scape is more uneven than the irrigated areas of
the arid and semiarid regions. Because of this, and
because of the occasional nature of supplemental
irrigation in the humid area, sprinkler systems are
used almost exclusively. The nature of the land-
scape limits the naturally available supplies of
water that can be used for supplemental irrigation.
Specific Difference Between Humid and
Arid Regions
The effect of a specific water quality deterrent
on plant growth is governed by related factors.
Basic principles involved are almost universally
applicable, but the ultimate effect must take into
consideration these associated variables. It has
been previously stated that the effect of any given
water quality deterrent on plant growth is greatly
affected by the sensitivity of that plant to the de-
terrent, soil characteristics, and the climatic en-
vironment. The amount of irrigation water used
and soil drainability are also contributing factors.
For this reason, water quality criteria for supple-
mental irrigation in humid areas may differ from
those indicated for arid and semiarid areas where
the water requirements of the growing plant are
met almost entirely by irrigation.
Plant sensitivity to a given deterrent is a fixed
characteristic of a given species. When irrigation
water containing a deterrent is used, its effect on
plant growth may vary, however, with the stage of
growth at which the water is applied. In arid areas,
plants may be subjected to the influence of irriga-
tion water quality continuously from germination
to harvest. Where water is used for supplemental
irrigation only, the effect on plants will depend not
only upon the growth stage at which applied, but
to the length of time that the deterrent remains in
the root zone (95). Leaching effects of interven-
ing rainfall must be taken into consideration.
Quality of water applied by sprinkler irrigation
will affect both foliar absorption and absorption of
the constituents found in that water. Although
some sprinkler irrigation is found in arid and semi-
arid regions, it is the dominant type used for sup-
plemental irrigation in humid regions. It is, there-
fore, of primary concern in the latter.
Climatic differences between humid and arid
regions also influence criteria for use of irrigation
water. The amount of rainfall determines in part
the degree to which a given constituent will accu-
mulate in the soil. Other factors associated with
salt accumulation in the soil are those climatic con-
ditions relating to evapotranspiration. In humid
areas, evapotranspiration is generally less than in
arid regions and plants are not as readily subjected
to water stress. The importance of climatic condi-
172
-------
tions in relation to salinity was demonstrated by
Magistad, et al. (99). In general, criteria regard-
ing salinity for supplemental irrigation in humid
areas can be more flexible than for arid areas.
Soil characteristics represent another significant
difference between arid and humid regions. Soils
in arid regions generally tend to be neutral or
alkaline, whereas those in humid regions tend to
be acidic. Mineralogical composition will also vary.
The composition of soil water available for ab-
sorption by plant roots represents the results of an
interaction between the constituents of the irriga-
tion water and the soil complex. The final result
may be that a given quality deterrent present in the
water could be rendered harmless by the soil, re-
main readily available, or that the dissolved consti-
tuents of a water may render soluble toxic concen-
trations of an element which was not present in the
irrigation water. An example of this would be the
addition of a saline water to an acid soil resulting
in a decrease in pH and a possible increase in solu-
bility of elements such as iron, aluminum, and
manganese (57).
Another significant characteristic of soils is their
adsorption, or ion exchange, properties. Not only
is the composition of the soil solution altered by
dissolved constituents in irrigation water, but the
physical properties of the soil may also be altered
by changes in ions adsorbed by the soil.
General relationships previously derived for
SAR and adsorbed sodium in neutral or alkaline
soils of arid areas do not apply equally as well to
acid soils found in humid regions (92). Further-
more, the effect of a given level of adsorbed sodium
(exchangeable sodium percentage) on plant
growth will be determined to some degree by the
associated adsorbed cations. The amount of ad-
sorbed calcium and magnesium relative to ad-
sorbed sodium is of considerable consequence,
especially when comparing acidic soils to ones
which are neutral or alkaline. Another example
would be the presence of a trace element in the
irrigation water which might be rendered insoluble
when applied to a neutral or alkaline soil, but
retained in a soluble, available form in acid soils.
For these reasons, soil characteristics, which differ
greatly between arid and humid areas, must be
taken into consideration.
Certain economic factors also influence water
quality criteria for supplemental irrigation. Al-
though the ultimate objective of irrigation is to
insure efficient and economic crop production,
there may be instances where an adequate supply
of good quality water is unavailable to achieve
this. A farmer may be faced with the need to use
irrigation water of inferior quality to get some
economic return and prevent a complete crop
failure. This can occur in humid areas during
periods of prolonged drought. Water quality cri-
teria are generally designed for optimum produc-
tion, but consideration must be given also to sup-
plying guidelines for use of water of inferior quality
to avert a crop failure.
Specific quality criteria for
supplemental irrigation
A previous discussion of potential quality de-
terrents contained a long list of factors indicating
the current state of our knowledge as to how they
might relate to plant growth. Criteria can be es-
tablished in two ways: (a) by determining a con-
centration of a given deterrent which when ad-
sorbed on, or absorbed by, a leaf during sprinkler
irrigation results in adverse plant growth, and (b)
by evaluating the direct and/or indirect effects that
a given concentration of a quality deterrent will
have on the plant root environment as irrigation
water enters the soil. Neither evaluation is simple,
but the latter is most complex since so many vari-
ables are involved. Since sprinkler application is
most common in humid areas for supplemental
irrigation, both types of evaluation have consider-
able significance. The following discussion relates
only to those quality criteria that are specifically
applicable to supplemental irrigation.
Salinity
General concepts regarding soil salinity as pre-
viously discussed are applicable. Actual levels of
salinity which can be tolerated for supplemental
irrigation must take into consideration the leaching
effect of rainfall and the fact that soils are usually
nonsaline at spring planting. The amount of irriga-
tion water having a given level of salinity that can
be applied to the crop will depend upon the num-
ber of irrigations between leaching rains, the salt
tolerance of the crop, and the salt content of the
soil prior to irrigation. Since it is not realistic to set
a single salinity value, or even a range, that would
take these variables into consideration, a guide was
developed to aid farmers in safely using saline, or
brackish, waters (93). The following equation was
used as a basis for this guide:
r;ri Tir* i n(EClw)
where ECt.(f) = electrical conductivity of the satu-
173
-------
ration extract after irrigation is
completed;
ECe(i) = electrical conductivity of the soil
saturation extract before irriga-
tion;
EClw = electrical conductivity of the irriga-
tion water; and
n = number of irrigations.
To utilize this guide, one must first consider the
salt tolerance of the crop to be grown and the soil
salinity level [ECe(f)] which will result in a 15 or
50-percent yield decrement for that crop. Then,
after evaluating the level of soil salinity prior to
irrigation [ECe(i)] and the salinity of the irrigation
water, the maximum number of permissible irri-
gations can be calculated. These numbers are
based on the assumption that no intervening rain-
fall occurs in quantities large enough to leach salts
from the root zone. Should leaching rainfall occur,
the situation could be reevaluated using a new
value forECe(i).
Using values based on a 50-percent yield decre-
ment (table IV-14, p. 150), and categorizing the
salt tolerance of crops as highly salt tolerant,
moderately salt tolerant and slightly salt tolerant,
the guide shown in table IV-20 was prepared to
indicate the number of permissible irrigations
using water of varying salt concentrations. This
guide is based on two assumptions:
(1) That no leaching rainfall occurs between
irrigations, and
(2) That there is no salt accumulation in the
soil at the start of the irrigation period. If
leaching rains occur between irrigations,
the effect of the added salt will be mini-
TABLE IV-20. Permissible Number of Irriga-
tions in Humid Areas With Saline Water
Between Leaching Rains for Crops of
Different Salt Tolerance* (97)
Irrigation water
Number of irrigations for
crops having
Total
salts
mg/l
640
1,280
1,920 . ..
2,560
3,200
3,840
4480
5,120
Electrical
conductivity
mmhos/cm.
at25C
. _ 1
2
3
4
5
6
7
8
Low
salt
tolerance
7
4
2
2
1
1
Moderate
salt
tolerance
15
7
4-5
3
2-3
2
1 2
1
High
salt
tolerance
11
7
5
4
3
2 3
2
1 Based on a 50-percent yield decrement.
mized. If there is an accumulation of salt
in the soil initially, such as might occur
when irrigating a fall crop on land to which
saline water had been applied during a
spring crop, the soil should be tested for
salt content and the irrigation recommen-
dations modified accordingly.
SAR Values and Exchangeable Sodium
The principles relating to this parameter and
the degree to which sodium is adsorbed from water
by soils are generally applicable in both arid and
humid regions. Some evidence is available (92),
however, to indicate that, for a given water quality,
less sodium is adsorbed by an acid soil than by a
base-saturated soil. For a given level of exchange-
able sodium, preliminary evidence indicates more
detrimental effects on acid soils than on base-
saturated soils (94). Since experimental evidence
is not conclusive at this point, detrimental limits
for SAR values previously listed will also apply to
supplemental irrigation.
Acidity and Alkalinity
The effect of the pH of irrigation water on crops
results primarily from the resultant effect on the
soil to which it is applied. The only consideration
not previously discussed relates to soil acidity
which is more prevalent in humid regions where
supplemental irrigation is practiced. Any factor
which will drop the pH below 4.8 may render
soluble toxic concentrations of iron, aluminum,
and manganese. This might result from application
of a highly acidic water, or from a saline solution
applied to an acidic soil. Since the nature of the
soil is the major determining factor, it is not feasi-
ble to set limits on the pH of the water. Specific
consideration must be given to each individual set
of conditions.
Trace Elements
Criteria and related factors previously listed are
equally applicable to supplemental irrigation. Cer-
tain related qualifications must be kept in mind,
however. First, foliar absorption of trace elements
in toxic amounts is directly related to sprinkler
irrigation. Critical levels established for soil or cul-
ture solutions would not apply to direct foliar
injury. Regarding trace element concentrations in
the soil resulting from irrigation water application,
174
-------
the volume of the water applied by sprinkler as
supplemental irrigation is much less than that
applied by furrow or flood irrigation in arid re-
gions. In assessing trace element concentrations in
irrigation water, therefore, total volume of water
applied and the physicochemical characteristics
of the soil must be taken into consideration. Both
of these factors could result in different standards
or criteria for supplemental irrigation as compared
with surface irrigation in arid regions.
other considerations
Organic Compounds
These are primarily pesticides, but may also con-
tain other types of organic quality deterrents origi-
nating from domestic and industrial sources. Here
again, quantity applied, soil characteristics, and
plant sensitivity must be taken into consideration.
BOD and Aeration
Although not a problem in normal irrigation
waters, it could be a problem where certain proc-
essing plant effluents are involved. Using sprinkler
application for supplemental irrigation, the com-
bined effects of the sprinkling and infiltration into
the soil provide considerable aeration which would
minimize this hazard. Where sprinkler irrigation is
used for effluent disposal and where the soil re-
mains excessively wet for long periods of
time, BOD may become a deterring factor, but
no specific information is available to enable
quantification.
Suspended Solids
Two factors regarding suspended solids must be
taken into consideration for sprinkler irrigation,
which are not significant for surface irrigation. The
first deals with the plugging up of sprinkler noz-
zles by these sediments. Size of sediment is a defi-
nite factor, but no specific particle size limit can be
established. Of the larger sediment particles that
do pass through the sprinkler, much of these can
be washed off certain leafy vegetable crops. Some
of the finer fractions, suspended colloidal material,
could accumulate on the leaves and, once dry, are
extremely difficult to wash off, thereby impairing
the quality of the product. These hazards increase
with frequency of irrigation and volume of water
applied.
Adequacy and achievability of criteria
Of all the criteria discussed, most information is
available regarding salinity. Yet a careful review
of this material indicates that it is most difficult to
assign tolerance limits, or even ranges of values,
for irrigation water. All research points to the
interactive effects of water table depth, soil type,
plant tolerances, and climatic conditions. Soil
salinity itself is not only a function of salinity level
of the irrigation water, but also the volume and
rate of application and leaching effects of inter-
vening rainfall. The same is true for the sodium
hazard involved in certain saline waters. Adequate
guidelines do exist regarding salinity; and, although
a specific limit cannot be set, these guidelines can
be used to judge the suitability of a given water for
irrigation.
Our knowledge of the effect of trace elements in
irrigation water on plant growth is extremely lim-
ited. Work cited as being done in nutrient solutions
seldom provides sufficient information on toxic
limits for a variety of crops. Even if this were
available, the gap must be bridged between the
175
-------
content of that element in a given irrigation and
the resultant content in the soil solution following
irrigation. Here, again, availability of a given ele-
ment to plants will vary with soil characteristics.
In general, criteria for trace elements are inade-
quate and guidelines previously described are the
best generalizations that can be made with existing
information.
The BOD or COD value of water is important
for many uses, but its significance in irrigation
water has not been fully assessed. As previously
mentioned, it is not likely to be a problem where
sprinkler irrigation is used predominantly and ade-
quate soil drainability is maintained. For these
reasons, no specific criteria are prescribed.
It is evident that there is a great lack of informa-
tion regarding quality deterrents in water for irri-
gation in general. Guidelines are available for
some naturally occurring deterrents; but as the
pollution pattern of our water sources changes,
additional research will be necessary to evaluate
effects of these wastes on various crops and for a
range of soil conditions. This information is neces-
sary before adequate and achievable criteria can
be developed.
In view of the above discussion, it is apparent
that judicious use of water of impaired quality may
be more practical than water treatment. Adequate
guidelines are available for salinity, but additional
research is needed to develop comparable guide-
lines for other mineral and organic contaminants.
Steps to improve water quality
It is outside the scope of this report to discuss
water treatment in detail. Limited water treatment
possibilities must be reconciled with the economic
value of the crop being produced. For field irriga-
tion in general, treatment is not usually practical.
Where good quality water is necessary for high
value crop production in greenhouses, water treat-
ment may be feasible. Each case must be consid-
ered on its own merits.
Nevertheless, since good water management is
so germane to quality characteristics of irrigation
water, brief mention will be made of several meth-
ods whereby the quality of irrigation water can be
maintained or improved.
contents in streams are frequently high during low
flows and low during periods of high flow, inter-
mixing in the reservoir and strategic releases of
water can provide more uniform salinity levels in
the irrigation water.
Evaporation of water from reservoirs tends to
increase the salt content. Continuing studies are
being conducted on new materials and application
techniques to minimize this effect.
Elimination of nonbeneficial uses of water by
phreatophytes not only lessens the concentration of
salts through transpiration, but conserves water as
well. Lowering the water table and developing
mechanical and chemical techniques for elimina-
tion of phreatophytes will insure more efficient
water use and minimize salt hazards.
Salts are frequently added to irrigation water
from mineral springs, oil wells, industrial enter-
prises, mine waters, and urban areas. Each of these
sources must be considered individually to deter-
mine effective control measures.
Regulation of return flows according to quantity
and quality is another means of maintaining and
improving irrigation water quality. Utilization of
ponds and reservoirs to control streamflow can be
helpful in this respect.
Drainage water from irrigated lands in arid re-
gions is commonly more saline than the applied
water. This is especially true where reclamation of
saline soils is in progress. In coastal areas, irriga-
tion water quality can be maintained by bypassing
saline return flows directly to the ocean.
Desalting water may be a potential in the future
when technology permits production at a relatively
low cost. Desalted water can be used directly for
irrigation, for augmenting low flows, or for mixing
with poor quality water. For the use of desalted
water to be feasible, adequate opportunities for
disposal of the resulting brine must be available.
Water shortages in some areas emphasize the
need for conjunctive use of ground and surface
waters. One aspect of this involves more effective
use of ground water storage potential. Increasing
ground water recharge to make use of this potential
would be most beneficial. The threat of gradual
deterioration in ground water quality through diffi-
culties in achieving basin salt balance could be
mitigated by greatly expanded utilization of ground
water storage resources.
Total Dissolved Solids
Uniformity of irrigation water quality can be
achieved through stream regulation by controlling
release of water from storage reservoirs. Since salt
176
Sediment
One of the major ways of minimizing the sedi-
ment burden of streams is through proper water-
shed management. Practices designed to provide
-------
effective ground cover, improve soil infiltration
characteristics, and stabilize waterways will insure
both efficient water conservation and help avoid
excessive soil loss. Sediment control is best effected
at its source: the watershed.
Unstable stream channels are another important
source of sediment. Rectification of stream chan-
nels and stabilization of streambanks will minimize
sediment production from this source.
Once sediment occurs in streams, it can be re-
moved where impoundments are used. The con-
struction of sediment traps has proved to be very
effective for this purpose, if properly designed.
Another possibility is the construction of desilting
works at diversion points. Chemicals have also
been used for flocculating colloidal sediments.
Phytotoxic Substances
The control of phytotoxic substances in irriga-
tion water is difficult. Where these materials origi-
nate from industrial or municipal sources, control
should be focused at the point of origin. Once they
are present in irrigation water, removal is not eco-
nomically feasible. Substances such as insecticides
and herbicides can be hazardous if misused. Con-
trol of the use of these materials can prevent their
becoming a problem in irrigation agriculture. There
are good indications that eliminating tail water and
other surface returns from irrigation provides an
excellent means for reducing and controlling pesti-
cide residues in return flows (73).
Monitoring and measuring
Certain principles relating to monitoring and
measuring water quality are common to all agricul-
tural uses. These will be discussed later. There are,
however, certain factors peculiar to irrigation
water sources which should be pointed out.
Sampling of water for analysis on a daily or
periodic basis will depend upon numerous varia-
bles, including: sources and adequacy of water
supply, crops grown, discharges of water quality
deterrents into the stream above the points of diver-
sion, and geographic location of irrigated areas
with respect to sources of supply.
Monitoring of water supplies on a scheduled or
unscheduled basis provides information for daily
or weekly irrigation unit operational purposes and
checks on changes in water quality resulting from
upstream changes. The frequency of sampling and
analysis for operational purposes will be dependent
upon previously obtained and correlated data with
the timing of additional samples and parameters
to be evaluated, based upon conditions peculiar to
each geographic area. If significant changes in con-
centrations or constituents are noted from water
samples taken, increased frequency of sampling
and additional monitoring points may be desirable.
Possibility of industrial wastes upstream should be
evaluated.
Historical water quality data should be reviewed
when considering the type, location, and frequency
of sampling. If such data are not available, a sys-
tematic water quality sampling program to provide
background information is often desirable to evalu-
ate changes in water quality which may occur with
time.
Water for a given area may be obtained from
one or more sources; i.e., ground water, one or
more surface reservoirs, unregulated streamflows,
and return flows from other uses. The ground
water source may be directly used by pumping
from the formation, or by ground water discharges
to a river upstream of the point of irrigation diver-
sion. As quality variations usually occur very
slowly in underground supply sources, sampling of
the source can be at intervals of several months
and often can be safely taken on a yearly basis.
In instances where ground water discharges up-
stream from the point of diversion form a signifi-
cant portion of the total supply, depletion of the
ground water discharge may affect the quality of
water in the stream. Under such conditions, pru-
dent management would provide for regular as-
sessment of sources and the quality implications of
changes in available supplies.
Unregulated streams can be expected to have
the largest fluctuations in water quality throughout
the year. Monitoring programs for such streams
generally will require sampling at more frequent
intervals. During periods of flood flows, monitor-
ing of suspended solids is important. The fre-
quency of sampling can be reduced as the percent-
age of the stream system regulated by reservoirs is
increased.
Operation of reservoirs can improve the quantity
and quality of water at downstream locations. At
locations where water temperatures may be an
important variable to monitor, vertical profiles of
reservoir water temperature should be obtained
before releases; and, where possible, water should
be released from that segment of reservoir having
the most favorable temperature. With reservoirs
on two or more streams supplying water to the
same lands, adequate data should be obtained to
provide for either operational blending of supplies
or to indicate that direct delivery will not have any
adverse effects on lands or crops.
177
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MONITORING water for specific pollutants
requires acceptable sampling and analyti-
cal procedures and the following references con-
tain such guides and procedures. This doesn't pre-
clude the use of other reliable methods (21, 123,
137,159,175,181).
The methodology for pesticides is currently
somewhat dispersed. For purposes of clarity and
as an aid to laboratories, the following recom-
mended instructions for extraction and analysis
are set forth.
sampling and
analytical procedures
Methods for Analyses of Chlorinated and
Phosphate Pesticides in Water
For extraction and preparation of the samples
for multple detection (electron capture or therm-
ionic gas-liquid chromatography and confirma-
tion by thin-layer chromatography), follow the
methods of Burchfield, et al. as outlined in Analysis
of Pesticide Residues (174).
General Discussion of extraction of pesticides
from water. Generally, in batch-method extrac-
tion, chloroform is the solvent of choice, with the
following modifications. After extraction, pass the
combined chloroform extracts through a column
of anhydrous sodium sulfate, collecting the eluate
in a 500 ml Kuderna-Danish evaporator fitted with
a calibrated collection tube. When all of the extract
has passed through, rinse the column with three
5 ml portions of hexane. Add a 20-mesh carborun-
dum boiling chip and place a Snyder column on
the Kuderna-Danish evaporator and concentrate
to about 5 ml. Add 25 ml hexane to evaporator
and concentrate to about 5 ml. Repeat addition of
hexane and concentrate two more times to elimi-
nate most of the chloroform. After last evapora-
tion, dilute to 10 ml with hexane for determination
by electron-capture gas chromatography and con-
firmation by thin-layer chromatography.
Continuous methods are used only when it is
necessary to extract large volumes of water and are
adapted more to research purposes than to routine
analysis.
In determinations, no cleanup is necessary if
potable water is being analyzed and the analyst can
go directly to electron-capture or thermionic gas
chromatography with thin-layer chromatography
for confirmation if necessary. Operating parame-
ters, retention times, and supporting data are found
in the FDA pesticide analytical manual (173).
The complete methods are given A.O.A.C. 79th
annual meeting (33) and changes in these methods
178
-------
are discussed in the A.O.A.C. 80th annual meeting
(34).
For chlorinated pesticides, use electron-capture
chromatography and methods described in
A.O.A.C. 79th annual meeting (33). Use of the
thermionic gas chromatography is discussed in the
1967 changes in methods (34). Additional infor-
mation on use of thermionic gas chromatography
can be found in other references (62, 63).
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(755) WADSWORTH, J. A. 1952. Brief outline of the
toxicology of some common poisons. Vet. Med.
7(10): 412-416.
(786) WALTER, A. H. 1964. The hidden danger in
water. Dairy Ind. pp. 678-679.
(187) WANG, WEN-LAN Lou, and S. G. DUNLOP. 1954.
Animal parasites in sewage and irrigation water.
Sewage and Ind. Wastes 26: 1020.
(188) WASHINGTON STATE POLLUTION CONTROL COM-
MISSION. Information bulletin on proposed water
quality standards. Water Control News No.
39: 8-9.
(789) WATERFOWL DEATHS FROM ALGAE. 1960. Out-
door California 21: 14.
(790) WATERS FOR AGRICULTURE PURPOSES IN WEST-
ERN AUSTRALIA. 1959. J. of Agr. of W. Aus-
tralia 3: 2.
(797) WATER SYSTEM COUNCIL. Water system and
treatment handbook. 3d. ed. Glenville, 111.
(792) WATER TREATMENT AND USE COMMITTEE. 1961.
Summary of research on individual household
and farmstead water supplies. Amer. Soc. Agr.
Eng.
(193) WEIBEL, S. R., R. B. WEIDNER, J. M. COHEN,
and A. G. CHRISTIANSON. 1966. Pesticides and
and other contaminants in rainfall and runoff.
J. Amer. Water Works Assn.
(194) WIERENGA, P. J., and R. M. HAGAN. 1966. Ef-
fects of cold irrigation water on soil temperature
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14-16.
(795) WILCOX, L. V. 1955. Classification and use of
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(796) WILCOX, L. V. 1948. Explanation and inter-
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Agr. Cir. 784.
(797) WILCOX, L. V. 1948. The quality of water for
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(798) WILLIAMS, H. B. 1939. Chronic lead poison-
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(799) WISE, W. S. 1948. The industrial waste prob-
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man, pp. 19-21.
184
-------
Section V
industry
-------
introduction
WATER QUALITY requirements differ so
widely for the hundreds of uses to which
water is put industrially that no meaningful criteria
for surface water supplies can encompass a ma-
jority of such uses. Furthermore, water treatment
technology in its present state of development per-
mits the utilization of surface water of literally any
available quality to create waters of any desired
quality at point of use. Such treatment may be
costly, but this cost is usually a small part of the
total production and marketing costs. The National
Technical Advisory Subcommittee for Water Qual-
ity Requirements for Industrial Water Supplies has
identified the appropriate quality characteristics of
raw waters that have been used and the quality
requirements of waters at the point of use for each
industry.
Each value given in this report for a quality
characteristic of raw water supplies for industrial
purposes has occurred in water that has been used
somewhere in this country. However, the charac-
teristic values may be altered by treatment to pro-
duce the quality of water required at point of use.
Hence, tables listing desired water quality criteria
at the point of use prior to internal conditioning
have been developed for each major industrial
requirement.
186
-------
Conclusions
summary
and key criteria
TABLE V-l. Task Forces and Their
Assignments
Task
Force
Assignment
IV ..
V _-
VI ..
.Steam generation and cool-
ing.
.Textile, lumber, paper, and
allied products.
.Chemicals and allied prod-
ucts.
.Petroleum and coal products.
-Primary metal industries
. Food and kindred products,
and leather tanning and
finishing.
All SIC codes
and electric
utilities.
SIC 22, 24,
and 26.
SIC 28.
-SIC 29.
-SIC 33.
SIC 20 and 31.
The Subcommittee has reached the following
conclusions regarding the water quality character-
istics and requirements for industrial supplies.
(1) The quality characteristics of the water
supply for an established industry at a given site, if
allowed to deteriorate from the range usually ex-
perienced for those characteristics of significance
to that industry, can cause an undesirable increase
in the cost for treatment. On the other hand, an
improvement in the quality of the same supply
will not significantly decrease the cost of treatment
at an existing installation.
(2) Marked variations in the quality of an in-
dustrial water supply can result in deterioration of
product quality for some industries.
(3) The water quality requirements at the
point of use in each process in each industry as
distinguished from the quality characteristics at
the point of supply are generally well established
for each existing industrial process use. These
water quality requirements, however, vary consid-
erably even for the same process depending upon
the technological age of the design and other
factors.
(4) The quantity of water employed for process
use by different plants in the same industry may
vary considerably between plants depending on the
cost of treatment, the age of the plant design, op-
erating practices, and the quality and quantity of
the available supply.
Industries considered
The Subcommittee was subdivided into six task
forces. Task force I was concerned with water used
for cooling and steam generation for all industries.
Each of the other task forces was assigned one or
more industrial groups as defined by the 2-digit
Standard Industrial Classification (SIC) coding
used by the Bureau of Census (6). Table V-l
lists the task forces and identifies the industrial
group or groups of concern. Additional detail on
the material considered is included in the sections
prepared by the several task forces.
Although it has not been feasible to cover all
industries, the major users of water, including some
industries that require process waters having a wide
range of quality, have been considered.
Water use
The total water intake of both industrial manu-
facturing plants and investor-owned thermal elec-
tric utilities was approximately 49,000 billion gal-
187
-------
Ions during 1964. About 90 percent or 44,000
billion gallons per year (bgy) of all intake water
was used for cooling or condensing purposes.
Water used for processing, including water com-
ing into contact with the product as steam or as
coolant, amounted to nearly 8 percent. (3,700
bgy) of the total water intake. The remaining 2
percent (960 bgy) was used for boiler-feed water.
Brackish water, water containing more than
1,000 mg/1 dissolved solids, amounted to nearly
30 percent (15,000 bgy) of the total intake water.
Most (32,000 bgy) of the fresh water intake (34,-
000 bgy) was surface water delivered by company-
owned water systems.
The manufacturing industry used approximately
4,300 billion gallons of water that they treated or
secured from a public supply in 1964. This was 30
percent of water intake for manufacturing and
approximates 90 percent of all water that they
used for boiler feed and processing.
Table V-2 summarizes the information on water
intake, recycling, and consumption, for each indus-
trial group considered.
Raw water quality
In general, the procedure used by the individual
task forces involved first establishing the quality
requirements for various waters at point of use ex-
clusive only of the addition of internal conditioning
chemicals such as biocides, or corrosion or deposit
inhibitors. Second, the consideration of methods of
external treatment (e.g. clarification, softening,
demineralization, etc.) that have been used; and
finally establishing the quality characteristics of
raw surface waters that have been used by the
various industries.
Minimum standards
Minimum standards that should be met by all
surface waters for all uses include the following
(3). The water should be:
(1) Free from substances attributable to mu-
TABLE V-2. Industrial and Investor-Owned Thermal Electric Plant Water Intake, Reuse, and
Consumption, 1964
[Source: 1963, census of manufacturers, water use in manufacturing (7) and water resources activities in the United States—electric
power in relation to the Nation's water resources (9)]
Water intake (bgy)
SIC
20
22
24
26
28
29
31
33
Purpose
Boiler feed
Cooling and sanitary
Industrial group condensing service, etc.
Food and kindred
products.
Textile mill products
Lumber and wood
products.
Paper and allied
products.
Chemicals and allied
products.
Petroleum and coal
products.
Leather and leather
products.
Primary metal in-
dustry.
Subtotal
Other industries.-
Total industry
Thermal electric
plants
Total . _
392
24
71
607
3,120
1,212
1
3,387
8,814
571
9,385
34,849
44,234
104
17
24
120
202
99
1
195
762
197
959
O
959 a
Process
264
106
56
1,344
564
88
14
996
3,432
271
3,703
3,703
Total
760
147
151
2,071
3,886
1,399
16
4,578
13,008
1,039
14,047
34,849
48,896
Water
recycled
(bgy)
520
163
66
3,945
3,688
4,763
2
2,200
15,347
1,207
16,554
5,815
22,369
Gross
water use,
including
recycling
(bgy)
1,280
310
217
6,016
7,574
6,162
18
6,778
28,355
2,246
30,601
40,664
71,265
Water
consumed
(bgy)
72
13
28
129
227
81
1
266
817
71
888
68
956
Water
discharged
(bgy)
688
134
123
1,942
3,659
1,318
15
4,312
12,191
968
13,159
34,781
44,940
1 Boiler-feed water use by thermal electric plants estimated
to be equivalent to industrial sanitary service, etc., water use.
2 Total boiler-feed water.
188
-------
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nicipal, industrial, or other discharges, or
agricultural practices that will settle to form
putrescent or otherwise objectionable
sludge deposits;
(2) Free from floating debris, oil, scum, and
other floating materials attributable to
municipal, industrial, or other discharges,
or agricultural practices in amounts suffi-
cient to be unsightly or deleterious;
(3) Free from materials attributable to mu-
nicipal, industrial, or other discharges, or
agricultural practices producing color,
odor or other conditions in such a degree
as to cause a nuisance.
Additional quality characteristics of surface
waters that have been used as sources for industrial
water supplies are summarized in table V—3. The
specific water characteristics are maximums and
no water will have all of the maximum values
shown.
Because of the very extensive use of water for
cooling and boiler-feed purposes, the quality char-
acteristics for surface waters for these purposes
have been given special emphasis. In general, the
surface water quality characteristics for process
waters are applicable for the 2-digit SIC group of
industries.
Parti.
steam generation
and cooling
190
-------
Description of industry
Task force I was concerned with quality criteria
for water used by virtually all industries for steam
generation and cooling. The task force's study in-
cluded Standard Industry Classifications 20
through 39, with the exception of 23 and 27, plus
the electrical utility industry. Water used for steam
that comes into direct contact with a product and
cooling water that comes into contact with a prod-
uct were, by definition, considered to be process
waters and, therefore, were not included in the
report of this task force.
Steam generation and cooling are unique water
uses in that they are required in almost every in-
dustry. Both uses are encountered under a very
wide variety of conditions that require a corres-
pondingly broad range of water quality criteria.
For example, steam may be generated in boilers
that operate at pressures ranging from less than 10
pounds per square inch (psig) for space heating to
more than 3,500 psig for electric-power generation.
For any particular operating pressure, the required
boiler water quality criteria depend upon many
factors in addition to the water temperature in the
steam generator. Thus, the amount of potentially
scale-forming hardness that is present in the make-
up water to a very low pressure boiler is of far less
importance when the steam is used for space heat-
ing than when it is used for humidification of air.
In the first case, virtually all of the steam is re-
turned to the boiler as condensate, whereas in the
second case, none of it returns to the boiler. Even
when operating at the same drum pressure and
makeup rate, a higher hardness is acceptable in
the makeup water to boilers with low-heat transfer
ratings than to those with high ratings.
From these few examples, it should be apparent
that any general criteria for boiler feed water
quality could not be applied directly to an indi-
vidual boiler plant without further consideration of
operating temperatures and pressures, boiler de-
sign, makeup rates, and steam uses. All of these
affect the nature of the water-caused problems that
might be anticipated in the boiler and its
auxiliaries.
Cooling water uses are similarly diverse. They
may be once through or recirculated. Once through
cooling waters are drawn from amply large sources
such as rivers, lakes, or extensions of the sea. They
are returned to those sources or to other large bod-
ies of water after having passed through heat ex-
change equipment just once. The quantities of
water required for once through cooling are so
huge that it is rarely economically feasible to alter
their quality by treatment. The most common ex-
ception is chlorination for control of biological
organisms that interfere with waterflow or heat
transfer.
In recirculating, cooling water systems, the water
withdrawn from the river or lake is small in com-
parison with the rate of circulation through the
heat transfer equipment. Under these conditions,
water treatment is economically feasible. Indeed,
it becomes a necessity because of the changes in
water composition produced by evaporation and
other processes encountered during recirculation.
As in the case of steam generation, there is such
a great variety of cooling equipment used, such a
wide range of chemical and physical changes that
can take place in the cooling water, and such a
variety of water treatment and conditioning meth-
ods available, that quality criteria for makeup
water to recirculating cooling systems can have
only very limited practical significance. The needs
of any specific system must be established on the
basis of the construction and operating character-
istics of that particular system.
Processes utilizing water
Steam Generation
Intake: In 1964, manufacturing plants used
about 960 billion gallons of water for boiler feed
(makeup), sanitary service, and uses other than
process or cooling (7). No basis is given for a
breakdown of this figure into its components, but
boiler feed (makeup) is the larger part.
No data are available for boiler makeup require-
ments of thermal electric powerplants. However,
these are small compared with their cooling water
requirements. It is estimated, therefore, that the
boiler makeup requirements of thermal power-
plants approximate the "boiler-feed, sanitary serv-
ice, and other uses" (7) in the industrial require-
ments so that the total intake for steam generation
in the year 1964 is assumed to have been approxi-
mately 960 billion gallons.
Recycle: Recycle of condensed steam back to
the boiler will vary from 0-percent for some indus-
trial uses and district steam plants to almost 100
percent for thermal power generation plants.
Consumption: Boiler makeup will vary from
negligible losses and blowdown in the thermal
powerplants to substantially the total water intake
in district steam plants with no returned steam
condensate. Even for these, the condensate usually
191
-------
goes to a sewer from which it ultimately returns to
a surface water course and so cannot be said to
have been consumed.
It is estimated that 10 percent of the intake
water is either lost to the atmosphere or incorpo-
rated in products. Thus, the total water consump-
tion for steam generation is about 96 bgy.
Discharge: Discharge is boiler blowdown and
steam condensate that is lost to sewers. This cor-
responds to the difference between intake and con-
sumption or 860 bgy.
Cooling Waters
Once through cooling: Once through cooling
water use in industry during 1964 was at the rate
of approximately 2,900 bgy for steam electric
power generation and 6,500 bgy for other uses
(7).
Total cooling water use in thermal electric
power plants was 27,000 bgy in 1959 and is esti-
mated at 57,000 bgy for 1970 (9). Assuming for
simplicity that the rate of change will be linear, the
probable use for 1964 was 41,000 bgy. It is esti-
mated that recirculation in these plants is 5,800
bgy, so that once through cooling required 35,000
bgy. These figures do not include water used in
public-owned steam generation plants for which
no data were available.
The total water quantities used for once through
cooling are summarized in detail on the following
page.
TABLE V-4. Quality Characteristics of Surface Waters That Have Been Used for Steam Generation
and Cooling in Heat Exchangers
[Unless otherwise indicated, units are mg/l and values are maximums. No one water will have all the maximum values shown.]
Boiler makeup water
Cooling water
Industrial
Electric
utilities
Once through
Makeup for recycling
Characteristic
Low and
medium High pressure
pressure 700 to 1,500 High pressure
0 to 700 psig psig > 1,500 psig
Fresh
Brackish '
Fresh
1 Brackish water—dissolved solids more than 1,000 mg/l by
definition 1963 census of manufacturers.
2 Accepted as received (if meeting total solids or other limit-
ing values); has never been a problem at concentrations
encountered.
3 Zero, not detectable by test.
Brackish l
Silica (SiO2) 150 150 150 50 25 150 25
Aluminum (Al) 33 3 3 (2) 3 (2)
Iron (Fe) 80 80 80 14 1.0 80 1.0
Manganese (Mn) 10 10 10 2.5 0.02 10 0.02
Copper (Cu) (2) f) (2) (2) (2) (') (")
Zinc (Zn) O (2) (2) (2) (2) (2) (2)
Calcium (Ca) (2) f) (2) 500 1,200 500 1,200
Magnesium (Mg) (2) (2) (2) (2) (2) (2) O
Ammonia (NH3) (2) (2) (2) (2) (2) (2) (2)
Bicarbonate (HCO3) 600 600 600 600 180 600 180
Sulfate (SO,) 1,400 1,400 1,400 680 2,700 680 2,700
Chloride (Cl) 19,000 19,000 19,000 600 22,000 500 22,000
Nitrate (NO3) (2) O (2) 30 (2) 30 (2)
Phosphate (P0») (2) (2) 50 4 5 4 5
Dissolved solids 35,000 35,000 35,000 1,000 35,000 1,000 35,000
Hardness (CaCO3) 5,000 5,000 5,000 850 7,000 850 7,000
Acidity (CaCO3) 1,000 1,000 1,000 (3) (3) 200 (')
Alkalinity (CaCO3) 500 500 500 500 150 500 150
pH, units (2) (2) (2) 5.0-8.9 5.0-8.4 3.5-9.1 5.0-8.4
Color, units 1,200 1,200 1,200 (2) (2) 1,200 (2)
Organics:
Methylene blue active 1 2 10 1.3 (2) 1.3 1.3
substances.
Carbon tetrachloride 100 100 100 (4) (') 100 100
extract.
Chemical oxygen demand (02) 100 100 500 (2) (2) 100 200
Odor (2) (2) (2) (2) (2) (2) (')
Hydrogen sulfide (H2S) (2) (2) (2) (2) 4 (2) 4
Dissolved oxygen (O2) (2) (2) (2) (2) O (2) (2)
Temperature, F 120 120 120 100 100 120 120
Suspended solids 15,000 15,000 15,000 5,000 250 15,000 250
4 No floating oil.
NOTE.—Application of the above values should be based
upon analytical methods in Part 23, ASTM book of standards
(1) or APHA Standard methods for the examination of water
and wastewater (5).
192
-------
Use:
Water
quantities,
bgy
Industrial-steam electric generation 2,856
Other 6,529
Commercial power 34,849
Total 44,234
A further detailed breakdown of these water
quantities can be made by identifying the water as
fresh or brackfish.
Water quantities, bgy
Fresh - --
Brackish
Total _ -
Industrial
6,549
2,836
9,385
Commercial
power
23,104
11,745
34,849
Total
29,653
14,581
44,234
Recirculation: The quantities of water used for
fresh water recirculation are shown in the tabula-
tion and are based on the following assumptions:
Fresh water recirculation, bgy
Commercial
Industrial
374
16,533
249
125
power
102
5,815
68
34
Total
476
22,348
317
159
Intake
Recirculation 16,533
Consumption
Discharge
Some plants recirculate brackish water, but be-
cause of the limited number of such operations,
water quantities have not been established for this
type of cooling.
Significant Indicators of Water Quality
Table V-4 shows the quality characteristics of
surface waters that have been treated by existing
processes tb produce waters acceptable for boiler
makeup and cooling.
Table V-5 shows quality requirements for both
boiler-feed water and cooling' water at point of
use. These values are for waters that have already
been processed through any required "external"
water treatment equipment, such as niters or ion
exchangers, but have not yet received any required
application of "internal" conditioning chemicals.
This information is included to allow estimation of
costs of treating raw waters. It does not imply that
waters of poorer quality cannot be utilized for
boiler-feed water or cooling in specific cases.
The values for water quality requirements at
point of use must be considered only as rough
guides. Thus, in the case of boiler-feed water
makeup, the maximum concentrations refer to the
upper end of the steam pressure range shown.
Usually, more liberal concentrations are accepta-
ble in feed water for boilers operating at lower
pressures within each range. However, even here
there are many deviations in practice because of
differences in the construction and operation of
different boilers. For example, all other things
being equal, the higher the makeup rate, the higher
the quality of the makeup water should be.
Water treatment processes
The water treatment processes marked by an
"X" in the following table are used in producing
water of the appropriate quality for either cooling
or boiler makeup. Commonly used internal con-
ditioning processes are also included. Not all of
these processes are used, however, if the raw water
quality is such that the treatment is unnecessary.
Cooling
Once
through
Recir-
culated
Dissolved gases removal:
Degasification mechani-
cal — X
Degasification-vacuum X —
Degasification-heat — —
Internal conditioning:
pH adjustment X X
Hardness sequestering.. X X
Hardness precipitation.. — —
Corrosion inhibition
general — X
Corrosion embrittlement. — —
Corrosion oxygen
reduction — —
Sludge dispersal X X
Biological control X X
Boiler
makeup
Suspended solids and colloids
removal:
Straining X X
Sedimentation X X
Coagulation — X
Filtration — X
Aeration — X
Dissolved solids modification
softening:
Cold lime — X
Hot lime soda — —
Hot lime zeolite — —
Cation exchange sodium, — X
Alkalinity reduction:
Cation exchange hydro-
gen — X
Cation exchange hydro-
gen and sodium — X
Anion exchange — —
Dissolved solids removal:
Evaporation — —
Demineralization — X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NOTES.— "—" Not used.
"X"—May be used.
193
-------
TABLE V-5. Quality Requirements of Water at Point of Use for Steam Generation and Cooling
in Heat Exchangers
[Unless otherwise indicated, units are mg/l and values that normally should not be exceeded. No one water will have all the
maximum values shown.]
Boiler feed water
Cooling water
Quality of water prior to the addition of
substances used for internal conditioning
Characteristic
Silica (SiO2)
Aluminum (Al)
Iron (Fe)
Manganese (Mn)
Calcium (Ca)
Magnesium (Mg)
Ammonia (NH4)
Bicarbonate (HC03)
Sulfate (SO4)
Chloride (Cl)
Dissolved solids
Copper (Cu)
Zinc (Zn) _ .
Hardness (CaCCs) _
Free mineral acidity
(CaCO3).
Alkalinity (CaCCs)
pH, units
Color, units
Organics:
Methylene blue active--
substances.
Carbon tetrachloride ___
extract.
Chemical oxygen demand
(0,).
Dissolved oxygen (O2)
Temperature, F
Suspended solids
Low
pressure
0 to 150
psig
30
5
1
0.3
O
O
0.1
170
9
700
0.5
O
20
0
140
8.0-10.0
O
1
1
5
2.5
10
Industrial
Inter-
mediate
pressure
150 to 700
psig
10
0.1
0.3
0.1
9
0.1
120
O
O
500
0.05
9
100
8.2 10.0
O
1
1
5
0.007
5
High
pressure
700 to 1,500
psig
0.7
0.01
0.05
0.01
0.1
428
O
200
0.05
40
8 2 9.0
O
0.5
0.5
0.5
0.007
9
Electric
utilities
1,500 to
5,000 psig
0.01
0.01
0.01
O
O
C)
0.7
9
O
0.5
0.01
8.8-9.2
O
O
O
O
0.007
9
Once through Makeup for recirculation
Fresh
52°
O
(2)
200
0
0
600
680
600
1,000
O
850
500
5.0-8.3
O
O
75
(2)
O
5,000
Brackish 1
25
9
420
O
140
2,700
19,000
35,000
O
O
6,250
0
115
6.0-8.3
O
O
75
0
2,500
Fresh
50
0.1
0.5
0.5
50
O
24
200
500
500
O
130
20
0
O
1
1
75
O
100
Brackish *
25
0.1
0.5
0.02
420
O
O
140
2,700
19,000
35,000
O
6,250
0
U25
1
2
75
O
0
100
1 Brackish water—dissolved solids more than 1,000 mg/l by
definition 1963 census of manufacturers.
2 Accepted as received (if meeting total solids or other limit-
ing values); has never been a problem at concentrations en-
countered.
3 Zero, not detectable by test.
4 Controlled by treatment for other constituents.
5 No floating oil.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1). or APHA Standard
methods for the examination of water and wastewater (5).
194
-------
Part II.
textile, lumber, paper
and allied products
textile mill products
(SIC 22)
Description of industry
The production of textiles is an ancient house-
hold art, but with the industrial revolution the
production of textiles was rapidly changed to mills
with mass production processes. At first, mills were
located near rivers for water power. The mills also
needed clear soft water for processing and there-
fore the textile industry developed in New England
where both water power and good quality process
water were available. Because much of their raw
material (cotton) was produced in the Southeast,
the textile plants gradually moved their cloth pro-
duction and then their finishing process plants to
the Southeast. By this time, mills were powered by
coal or electricity so that many of them moved to
communities which were located on the ridges.
Many plants located on the Piedmont Plateau
where the raw process water was soft but turbid.
The technology of water treatment was sufficiently
well developed that the turbidity was easily
removed.
With time, the new synthetic fiber plants were
located near the natural fiber plants. (The syn-
thetic fiber production is part of the chemical
industry.)
Natural fibers are spun, teased, and woven in
the dry state, except for some stiffening of the
warp; this latter process is known as sizing. The
thread is run through the size which is dispersed
in a highly concentrated water suspension. The
natural fibers in the cloth are generally scoured
to remove the sizing and natural waxes before
bleaching and dyeing. Synthetic fibers which may
be mixed with natural fibers in the cloth are
also scoured, but this is incidental. The cloth is
bleached before dyeing to obtain a more repro-
ducible color each time a specific dye is used.
Water is used for scouring, bleaching, rinsing,
and dyeing. The quality requirement for dyeing
approaches that of distilled water.
In a very new development, water is used in
place of a mechanical shuttle for weaving synthetic
fibers. Except for dissolved gases and viscosity,
the quality characteristics of this water have no
significance.
Processes utilizing water
The sizing or stiffening of the warp fibers by
195
-------
starch or modified starches and cellulose com-
pounds requires only small amounts of water for
making the 10-percent suspensions, but because
of the large number of mills and changes in size
suspensions needed, the total water used is about
2 percent of the process water for cotton (SIC's
2211, 2221, 2231). No recycling is practiced.
The scouring of cotton and wool fibers and/or
fabrics is widely practiced. While water quantity
requirements are large, the quality requirements
for specialized textile or fiber products are quite
rigorous. Scouring is done at temperatures of 80
to 120 C and at pH 12 for cotton, but at much
lower temperatures of 30 to 50 C and at pH 2 to
4 for wool. The water is not recycled in the scour-
ing though large volumes of fabric may be scoured
in one batch. The rinsing operation may be de-
signed with counter current flow with use of the
discharge for makeup water in scouring operation.
The reuse of water in the textile industry is
limited to the newest mills, for any reuse or con-
servation is not common in the older mills. The
desizing of fabric is a cleaning operation that is
similar to scouring in its water requirements. These
operations involve 23 percent of the total process
water for the cotton textile industry. Mercerizing
of cotton is a specialized process which is becom-
ing much less significant with the introduction of
fiber blends and several cotton finishing plants
have discontinued its use. In 1963, when the cot-
ton textile industry figures were obtained, 13 per-
cent of the cotton was mercerized but this required
28 percent of the process water.
The bleaching of textiles is done with either
chlorine or hydrogen peroxide. Chlorine is gen-
erally used with cotton while hydrogen peroxide
TABLE V-6. Quality Characteristics of Surface
Waters That Have Been Used by the Textile
Industry (SIC 22)
[Unless otherwise indicated, units are mg/l and values are
maximum. No one water will have all the maximum values
shown.]
Characteristic
Iron (Fe)
Manganese
(Mn)
Coooer (Cu)
Dissolved
solids
Concen-
tration
0.3
1.0
0.5
150
Characteristic
Suspended
solids
Hardness
(CaCO,)
pH, units
Color, units _ _
Concen-
tration
1,000
120
6.0-8.0
C)
is used with blends containing synthetic fibers and
with wool. When chlorine is used, the solution is
generally adjusted to pH 9, but when hydrogen
peroxide is used, the pH is adjusted in the range of
2.5 to 3.0. Rinsing of the bleached fibers or cloth
requires a high quality water. Recent academic
studies have suggested reuse of this water for
preparing chlorine bleach, but the reuse is not
now practiced (SIC 226). The bleaching opera-
tions in the cotton textile industry uses 20 percent
of the process water.
Water for dyeing operations has very high qual-
ity criteria, but no higher than those needed in the
other processes. Cotton fibers (cloth) are dyed at
moderately high pH values while wool is generally
dyed at mildly acidic pH values. Synthetic fibers
are dyed at various pH values depending upon
the chemical character of the synthetic fiber. Water
from the dyeing operations cannot be reused. The
dyeing operations in the cotton textile industry use
approximately 32 percent of the process water.
Significant indicators of water quality
Table V-6 shows the quality characteristics of
raw waters that have been treated by existing proc-
esses to produce waters acceptable for the process
waters used by the textile industry. Table V—7
shows the water quality requirements at point of
use for the various processes within the textile in-
dustry. These processes are sizing, scouring,
bleaching, and dyeing.
TABLE V-7. Quality Requirements of Water at
Point of Use by the Textile Industry (SIC 22)
[Water quality prior to addition of substances used for internal
conditioning. Unless otherwise indicated, units are mg/l and
values that normally should not be exceeded.]
Characteristic
Sizing
suspen-
sion
Scouring Bleaching Dyeing
1 Accepted as received (if meeting total solids or other limit-
ing values); has never been a problem at concentrations
encountered.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater, (5).
Iron (Fe) 0.3 0.1 0.1 0.1
Manganese (Mn)_ 0.05 0.01 0.01 0.01
Copper (Cu) 0.05 0.01 0.01 0.01
Dissolved solids,. 100 100 100 100
Suspended
solids 5555
Hardness
(CaCO3) 25 25 25 25
pH, units:
Cotton 6.5-10 9.0-10.5 2.5-10.5 7.5-10.0
Synthetics 6.5-10 3.0-10.5 C) 6.5-7.5
Wool 6.5-103.0-5.0 2.5-5.0 3.5-6.0
Color, units 5555
1 Not applicable.
NOTE.—Application of the above values should be based
upon analytical methods in Part 23 of the ASTM book of
standards (1), or APHA Standard methods for the examination
of water and wastewater (5).
196
-------
Water treatment processes
Textile mills require clear process water. Clarifi-
cation of surface water is practiced by all textile
mills that do not purchase potable water or use
ground water.
The early mills located on soft water supplies.
As available soft water sites were filled, mills
moved to hard water areas and practiced softening
or bought city water. Batch softening or seques-
tering with EDTA or polyphosphates is now prac-
ticed in the critical processes even when a mill has
a soft water supply. Demineralization is used by
a few mills where color matching in dyeing opera-
tions is critical.
Chlorination is used to prevent slime on the
piping but the concentration must be kept at a
minimum since reducing agents are frequently
required with sensitive dyes. Adjustment of the
pH to a slightly alkaline value for enhancing the
effectiveness of chlorine or chlorine dioxide in the
removal of manganese creates a problem in meet-
ing the pH requirements for some of the mill's
processes.
Control of corrosion is very critical in the water
distribution system because the corrosion products
can stain cloth. Manganese removal may be nec-
essary because loosened deposits of manganese
dioxide which accumulate on copper water heat-
ing pipes (coils) may create disastrous results in
rinsing operations.
lumber
and wood products
(SIC 24)
Description of industry and processes
utilizing water
In general, the lumber industry collects logs
from the forest and prepares them for use by saw-
ing the log into various shapes. In the early years
in this country, the logs were cut in the winter
when the snow was on the ground to lubricate their
transfer by dragging them overland to the river.
The river transported the log to a millsite. The
logs were frequently left in the water if they could
be fenced off or driven into a back water to pre-
vent them from going further downstream. While
the log was floating, the water prevented the log
from drying and cracking at the cut end.
Today, lumber may be transported to a mill
which may not be near a river. If the logs accumu-
late, it is necessary to keep their ends moist to pre-
vent cracking. This can be done by floating them
in a pond or by spraying the log pile. The log is
frequently debarked by water jets before cutting
it into the desired shape.
Some lumber is treated with chemicals to reduce
fire hazards, to retard insect invasion, or prevent
"dry rot." These preservation processes use small
volumes of water to prepare the solutions of
chromates, cupric ions, aluminum ions, silicates,
fluorides, arsenates, and pentachlorophenates.
Some forest products are processed mechanically
or chemically to make a variety of consumer
products.
Significant indicators of water quality
There are few significant indicators of water
quality for the lumber industry. The suspended
solids should be less than 3 mm in diameter and
the pH should preferably be between 5 and 9 to
minimize corrosion of the equipment. Water used
for transportation hardly qualifies as process water.
Water used for spraying logs or jet debarking
should be free of particles that clog the nozzles or
jet openings. Such water is frequently recirculated.
Water for preparation of solutions for treatment of
the lumber should be reasonably free of turbidity
and those ions which might react to form precipi-
tates. Frequently, because of the highly toxic
nature of these solutions, efforts are made to re-
cycle as much solution as possible. Thus, makeup
water is required to compensate for the portion of
the solution forced into the lumber under pressure
and then evaporated during seasoning.
Water treatment processes
For the lumber production phase only, straining
may be required. Clarification may be practiced
for water used in lumber preservation but this
would be necessary on only a very small volume.
TABLE V-8. Quality Characteristics of Waters
That Have Been Used by the Lumber Industry
(SIC 24)
Characteristic
Value
Suspended solids <3 mm, diameter.
pH, units 5 to 9.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater (5).
197
-------
paper
and allied products
(SIC 26)
Description of industry
The pulp and paper industries are those de-
scribed under the SIC Code Number 26. Since the
principal product is paper, including paperboard,
and the principal pulping processes are kraft and
groundwood, the data given will be for these major
processes. Specialty processes and products having
unique water quality requirements should be con-
sidered as special cases.
Processes utilizing water
The manufacture of pulp and paper is highly
dependent upon an abundant supply of water.
The major process water uses are preparation of
cooking and bleaching chemicals, washing, trans-
portation of the pulp fibers to the next processing
step, and formation of the pulp into the dry
product.
Census data (7) for 1964 indicate that about
1,300 bgy of water were used by this industry
and that about 74 percent or 990 billion gallons,
required treatment prior to use. However, these
data include water used for cooling, bearing
lubrication, pulp seals, and other non-process re-
quirements. If process water is defined as only
water that contacts the product, the estimated
usage is 500 bgy.
The process water required per ton of product
is estimated in figures V-l and V-2. Figure V-l
illustrates the typical Kraft process that is similar
to the major pulping processes having chemical
recovery. Wash water was estimated at 2,600 gal/
ton for unbleached and 10,000 gal/ton for wash-
ing bleached pulp. Transportation of the pulp was
estimated to require 4,000 gal/ton after each proc-
ess. The amount of water recycled was based on
the dilution required at each processing step and
is much higher than the data given by the Bureau
of the Census. Figure V-2 shows similar data for
a typical mechanical pulping mill. A summary of
the water used to produce finished paper products
by the three major processes is given below.
Process water requirements, gallons per ton
of product
Consump- Dis-
Intake1 Recycle tion charge
1,000 47,000 1,000 250
Mechanical
Pulping
Unbleached
chemical pulp
and paper 7,000 115,000 1,000 6,000
Bleached chemi-
cal pulp and
paper 20,000 250,000 1,000 19,000
1 Does not include about 250 gallons per ton of water present
in the woodchips.
CHEMICAL PULPING
2f
CM
o
s
o
ID
O
ID
"b ",
s :
EVAPORATION
550
4040
CHIPS
240
DIGESTER
EVAPO
RATION
500
BROWN STOCK
WASHING AND
SCREENING
CHEMICALS
1510
\2640
Additional water required
for bleaching pulp
5230
390
Figure V-l—Pulp and paper industry: water intake, recycle, and discharge.
gallons of water per ton of product.)
(All data given as
198
-------
Significant indicators of water quality
The quality characteristics of untreated surface
waters used by the pulp and paper industry are
given in table V-9. Treatment of the raw water
should provide water to the process with the qual-
ity requirements described in table V-10. Process
TABLE V-9. Quality Characteristics of Surface
Waters That Have Been Used by the Pulp and
Paper Industry (SIC 26)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum
values shown.)
Characteristics
Chemical pulp and paper
Mechanical
pulping Unbleached Bleached
Silica (Si02)
Aluminum (Al) . .
Iron (Fe)
Manganese (Mn) .
Zinc (Zn) ... _
Calcium (Ca) _
Magnesium (Mg) - -
Sulfate (SO,)
Chloride (Cl)
Dissolved solids
Suspended solids _
Hardness (CaC03)
pH, units
Color, units _ _ __ _
Temperature, F
O
C1)
2.6
C)
C)
C1)
C1)
C1)
1,000
1,080
C)
475
4.6-9.4
360
C)
50
C)
2.6
O
C)
o
o
o
200
1,080
C)
475
4.6-9.4
360
O
50
O
2.6
C)
O
C)
O
C)
200
1,080
C)
475
4.6-9.4
360
95
1 Accepted as received (if meeting total solids or other limit-
ing values); has never been a problem at concentrations
encountered.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (]), or APHA Standard
methods for the examination of water and wastewater (5).
steam quality requirements are the same as those
given under the steam generation and cooling
water section.
In general, clarification, sedimentation, or filtra-
tion, either singly or in combination, and some-
times followed by softening, are employed in treat-
ing water for the pulp and paper industry.
TABLE V-10. Quality Requirements of Water at
Point of Use by the Pulp and Paper Industry
(SIC 26)
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded. Quality of water prior to the
addition of substances used for internal conditioning.]
Chemical pulp and paper
Mechanical
Characteristics pulping Unbleached
Silica (SiO2)
Aluminum (Al)
Iron (Fe)
Manganese (Mn)
Zinc (Zn)
Calcium (Ca) _ _
Magnesium (Mg)
Sulfate (SO.)
Chloride (Ct) . _
Dissolved solids
Suspended solids
Hardness (CaCO3)
pH, units __
Color, units
Temperature, F
C)
O
0.3
0.1
C)
C)
O
C)
1,000
C1)
O
C)
6-10
30
C1)
50
C)
1.0
0.5
O
20
12
O
200
O
10"
100
6-10
30
0
Bleached
50
C)
0.1
0.05
C)
20
12
C)
200
O
10 2
100
6-10
10
95
1 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
2 No gritty or color-producing solids.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater (5).
MECHANICAL PULPING
EVAPORATION
390,
950
WOOD
EVAPORATION
550
240
MECHANICAL
PULP
240
Figure V-2—Flow diagram showing water intake, recycling, and discharge in gallons per ton of
product for pulp and paper making.by a typically mechanical pulping mill.
199
-------
Significant indicators of water quality
Part III.
chemical
and allied
(SIC 2
products
fi
The number and diversity of manufacturing
facilities in the chemical and allied products in-
dustries and their wide geographic location in the
United States are such that, the surface waters
which they use will vary widely in chemical con-
stituents. Water quality characteristics for raw
water supplies that have been used to provide
water for process use for each industry are listed
in table V-12. Table V-13 gives water quality
requirements at point of use by the various
industries.
Water treatment processes
The cost of water treatment is a very small part
of the overall cost of manufacturing in the chemi-
cal industry. The normal water purification con-
sists of clarification (coagulation, sedimentation,
filtration). This may be supplemented by soften-
ing, cold lime, lime soda, zeolite, and deminerali-
zation, singly or in combination to provide the
quality required from any source of raw surface
water. The technical skills available in the chemi-
cal industry are of such nature that proper water
treatment can be provided to produce water of
satisfactory quality for manufacturing processes,
under all conditions.
TABLE V-13.
[Unless otherwise indicated, units are mg/l and values
iption of industry
Task force III was concerned with the water
quality criteria for the chemical and allied products
industries. This is in accordance with the 1963
census of manufacturers water use in manufactur-
ing SIC's 2812-15, -18, -19, -21, -22, -34, -41,
-51, -61, 07, -71, -92. These waters are for
process use only and do not include either boiler
feed or cooling waters.
Processes utilizing water
The subject industries and their process water
intake are shown in table V-ll. No breakdown
has been made of the use by each process within
a given 4-digit SIC coding.
(1)
SIC 2812
alkalies and
Characteristic chlorine
Silica (SiO2)
Iron (Fe)
Manganese (Mn)
Calcium (Ca)
Magnesium (Mg)
Bicarbonate (HCO3).__
Sulfate (SO4)
Chloride (Cl)
Nitrate (NO3)
Total solids
Hardness (CaCO3)
pH
Color
Suspended solids
Odor
5-day BOD (O2)
COD (02)
Dissolved oxygen (O2)_
Alkalinity (CaC03)
0.1
0.1
9
O
O
O
9
9
0
9
o
o
0
0
(2)
SIC 2815
Interm. coal
tar products
3333333333333333333
1 Potable water.
2 Accepted as received (if meeting total solids
200
-------
TABLE V-l 1. Process Water Intake by Chemical
and Allied Product Industries With Total Water
Intake of 20 or More bgy During 1964
Process water intake
SIC
2812
2815
2818
2819
2821
2822
2834
2841
2851
2861
2871
2892
Industry group and industry
Alkalies and chlorine
Intermediate coal tar
products
Organic chemicals, n.e.c.1—
Inorganic chemicals, n.e.c.1
Plastic materials and
resins
Synthetic rubber
Pharmaceutical prepara-
tions _
Soaps and other deter-
gents _ _ _
Paints and allied
products
Gum and wood
chemicals
Fertilizers
Explosives
Subtotal
Nonlisted industries 2
Bgy
16
9
314
74
25
11
3
2
1
2
32
2
491
73
Percent
2.8
1.6
55.5
13.3
4.4
2.0
0.5
0.4
0.2
0.4
5.6
0.4
87.1
12.9
28
Chemicals and allied
products 564
100.0
1 Not elsewhere classified.
2 Although the industries selected for study probably deter-
mine the range in values of the various quality criteria for
process waters for chemical and allied products, it is noted
that 3 industries (SIC 2823, Cellulosic Man-Made Fibers;
SIC 2824, Organic Fibers Noncellulosic; and SIC 2891, Glue
and Gelatin) use 23, 8, and 6 bgy, which is more than several
of the industries under consideration.
TABLE V-12. Quality Characteristics of Surface
Waters That Have Been Used by the Chemical
and Allied Products Industry (SIC 28)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum values
shown.]
Characteristic
Silica (SiO2) ...
Iron (Fe)
Manganese
(Mn)
Calcium (Ca)
Magnesium
(Me)
Ammonia (NHs)
Bicarbonate
(HCO3)
Sulfate (SO4)
Chloride (Cl)
Dissolved
solids
Concen-
tration
o
5
2
200
100
O
600
850
500
2,500
Characteristic
Suspended
solids
Hardness
(CaCO3)
Alkalinity
(CaC03) _„.
pH units
Color
Odor
BOD (02)
COD (02)
Temperature ._
DO (O2)
Concen-
tration
10,000
1,000
500
5.5-9.0
500
C)
C)
C)
C)
()
1 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater (5).
Quality Requirements of Water at Point of Use by Chemical and Allied Products Industry (SIC 28)
that normally should not be exceeded. Quality of water prior to the addition of substances used for internal conditioning.]
(3)
SIC 2818
organic
chemicals
(2)
0.1
0.1
68
19
128
(2)
(")
(2)
C)
250
6.5-8.7
C)
O
O
(")
C)
C)
125
(4)
SIC 2819
inorganic
chemicals
(")
(2)
O
o
(2)
(2)
o
o
o
9
!•>
<2)
(2>
(2)
(2)
o
c2)
(2>
(5)
SIC 2821
plastic
materials
and
polymers
O
/2\
/2\
(2)
/2\
C)
o
9
o
0
o
9
9
0
o
o
(6)
SIC 2822
synthetic
rubber
(")
0.1
0.1
80
36
9
0
(2)
350
6.2-8.3
20
5
9
O
(2)
150
(7)
SIC 2834
drugs and
pharmaceu-
tical prep-
arations *
(2)
O
o
o
o
9
(2)
o
o
0
0
/2\
/2\
(2)
9
/2\
/2\
(8)
SIC 2841
soap and
other
detergents
(2)
/2\
/2\
/2\
(2)
O
/2\
/2\
(2)
(2)
9
9
(a)
(2)
o
0
(9)
SIC 2851
(10)
SIC 2861
paints and gums and
allied wood
products
(*)
O
(2)
9
9
o
9
9
o
C2)
0
0
9
o
chemicals
50
0.3
0.2
100
50
250
100
500
5
1,000
900
6.5-8.0
20
30
(3)
O
C)
C)
200
(ID
SIC 2871
fertilizers
O
o
9
(2)
(2)
o
o
9
(2)
C2)
o
0
0
0
9
o
(12)
SIC 2892
explosives
O
0
o
9
o
o
C)
9
(2)
o
9
(2)
o
(a>
(a>
o
or other limiting values); has never been a problem
at concentrations encountered.
1 No practical limit—any concentration can be handled.
4 Controlled by treatment for other constituents.
201
-------
iption of industry
Part IV.
petroleum and
coal products (SIC 29)
Today's oil industry is engaged in finding oil,
getting it out of the ground, transporting it, mak-
ing it into useful products, and marketing and
delivering these products to consumers.
The principal withdrawal of water is for refin-
ing. Other operations such as transportation of
crude oil and products and marketing rely on it,
but do not use significant amounts of water. Some
water is used in the producing branch for drilling
wells and operation of natural gasoline plants, but
the amount is insignificant in relation to that used
in the refining process.
Processes utilizing water
Separation, conversion, and treating operations
use large quantities of water. The 1963 Census of
Manufacturers (7) indicates a gross water use of
about 6,100 bgy in 1964. However, the water
intake to refineries for this same period shows that
only 1,400 billion gallons was taken in as supply.
This indicates substantial reuse of water. Ninety-
two percent of those reporting indicated that they
were reusing water.
Of the total water intake, 8 7-percent is used for
cooling purposes, 7 percent for boiler feed and
sanitary purposes and only 6 percent for process-
ing. Process water uses include desalting, washing,
barometric condensing, and product transpor-
tation.
One use of process water in refining operations
is the removal of brine from crude oil to prevent a
buildup of solids in the processing equipment and
to prevent hydrochloric acid corrosion problems.
Water quality for this operation is not critical.
Actually, waste water is frequently used for this
purpose because it provides a means whereby cer-
tain impurities, such as phenols, can be eliminated
from the waste water.
Most refinery products must be treated to im-
prove color, odor, or stability, or to remove sulfur,
gums, or other corrosive substances before the
product is marketable. Caustic, acid, and clay
treating, various sweetening operations, and sol-
vent extraction are some of the methods used.
Water is used in these operations for makeup of
caustic and acid solutions and for product wash-
ing. Lubricating oils are treated with acids, by
contact with or percolation through clay, or by
solvent extraction methods. Both steam and water
are used to recover solvents and to clean the filter
clays.
202
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Numerous operations use barometric con-
densers for creating low pressure conditions in
fractional distillation. The condenser water con-
tacts overhead products thereby dissolving pol-
lutants. For this reason, barometric condensers
are being replaced by surface condensers in
many cases.
Water under high pressure from cutting heads
is used to reduce the size of coke particles so that
they can be removed from the coking chambers.
Frequently, coke fines are removed by clarification
and the water reused. Wax manufacturing proc-
esses sometimes use water as a transporting
medium and the process water is then generally
recirculated.
Specific indicators of water quality
For process water requirements, refiners use
treated or untreated cooling water, public water
supplies, or ground water. Of the total water in-
take by refineries, about 84 percent is secured from
surface supplies, 7 percent from ground water,
and the remaining 9 percent from public water
supplies.
The primary treatment of water for process use
is for suspended solids and turbidity removal.
Some washing operations are normally provided
with water of about 10 mg/1 or less suspended
solids. However, there are many refineries that
do not treat process water.
The quality characteristics of surface waters
that have been treated by existing processes to pro-
duce waters acceptable for process use are given in
table V-14. The quality requirements at point of
use are given in table V—15.
TABLE V-14. Quality Characteristics of Surface
Waters That Have Been Used by the Petroleum
Industry (SIC 29)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum values
shown.]
Characteristic
Silica (SiO2)
Iron (Fe)
Calcium (Ca) __
Magnesium
(Mg) .
Total sodium and
potassium
(Na, K)
Bicarbonate
(HC03)
Sulfate (SOO
Concen-
tration
50
15
220
85
230
480
570
Characteristic
Chloride (Cl)___
Fluoride (F)
Nitrate (N03) ..
Dissolved
solids .
Suspended
solids _ _
Hardness
(CaCO3)
Color, units
pH, units
Concen-
tration
1,600
1.2
8
3,500
5,000
900
25
6.0-9.0
TABLE V-15. Quality Requirements of Water
at Point of Use for Petroleum Industry (SIC 29)
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded. Quality of water prior to the
addition of substances used for internal conditioning.]
Characteristic
Silica (Si02)
Iron (Fe)
Calcium (Ca) .
Magnesium
(Mg)
Total sodium and
potassium
(Na, K)
Bicarbonate
(HCO3)
Sulfate (SO,)—-
Chloride (Cl)- .
Fluoride (F)
Concen-
tration
o
75
30
O
O
V
300
C)
Characteristic
Nitrate (N03) _.
Dissolved
solids
Suspended
solids
Hardness
(CaCO3)
Noncarbonate
hardness
(CaCOs)
Color, units
pH, units
Concen-
tration
C)
1,000
10
350
70
C)
6.0-9.0
1 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater, (5).
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1). or APHA Standard
methods for the examination of water and wastewater (5).
203
-------
Description of industry
PartV.
primary metals
industries (SIC 33)
The industries which are incorporated within
the category of primary metals in this report are
those which are included in the Standard Indus-
trial Classification (SIC) Manual (6) as industry
group 33. This industrial group is defined as those
"establishments engaged in the smelting and re-
fining of ferrous and nonferrous metals from ore,
pig, or scrap; in the rolling, drawing, and alloying
of ferrous and nonferrous metals; in the manufac-
ture of castings, forgings, and other basic products
of ferrous and nonferrous metals; and in the manu-
facture of nails, spikes, and insulated wire and
cable. The major group also includes the produc-
tion of coke."
This section defines, as accurately as possible
at this time, the process water quality require-
ments for the industry.
Process water utilization by the primary metals
industry as given in the Bureau of the Census (7)
is summarized by the following table.
Process water utilization
Industry
Process water
used, 1964
SIC No. (billion gals.)
Iron and steel production 331 885
Iron and steel foundries 332 12
Copper industry 3331, 3351 36
Aluminum industry 3334,3352 20
All other primary metal
industries 43
Total process water, primary
metals 33 996
The production of iron and steel utilized almost
90 percent of all process water used by the in-
dustry. For this reason, water quality requirements
have only been included for this segment of the
industry.
Processes utilizing water
The iron and steel industry as defined for this
report includes pig iron production, coke produc-
tion, steelmaking, rolling operations, and those
finishing operations common to steel mills, such as,
cold reduction, tin plating, and galvanizing. Al-
though many steel companies operate mines for
ore and coal, ore beneficiation plants, coal cleaning
plants, and fabricating plants for a variety of spe-
cialty steel products, these are excluded from this
report.
Most of the iron and steel making facilities in
204
-------
the United States are centered in integrated plants.
These have generally been located in the midwest
and east where major water sources are available.
A few mills have been built in water-short areas
because of economic advantages which outweighed
the increased cost of recirculating water. The
major processes involved in the manufacture of
steel all require process water, some in several
ways. The succeeding paragraphs present a brief
description of the process and the process use of
water.
The production of coke involves the heating of
coal in the absence of air in order to rid the coal of
tar and other volatile products. Process water is
used in the direct cooling of the incandescent coke
after removal from the coke oven in a process
called coke quenching. This quenching process is
nothing more than dousing the coke with copious
amounts of water.
Pig iron production is accomplished in the blast
furnace. Process water is used to cool or quench
the slag when it is removed from the furnace. The
major use of process water in the blast furnace is
for gas cleaning in wet scrubbers. Steel is manu-
factured in open hearth or basic oxygen furnaces.
Process water may be used in gas cleaners for
either of these furnaces.
The major products of the steelmaking processes
are ingots. Ingots, after temperature conditioning,
are rolled into blooms, slabs, or billets depending
upon the final product desired. These shapes are
referred to as semifinished steel. Water is used for
cooling and lubricating the rolls. These semi-
finished products are used in finishing mills to
produce a variety of products such as plates, rails,
structural shapes, bars, wire, tubes, and hot strip.
Hot strip is a major product and the manufactur-
ing process for this item will be briefly described.
The continuous hot strip mill receives tempera-
ture conditioned slabs from reheating furnaces.
Oxide scale is loosened from the slabs by mechani-
cal action and removed by high pressure jets of
water prior to a rough rolling stand, which pro-
duces a section that can be further reduced by the
finishing stand of rollers. A second scale breaker
and series of high-pressure water sprays precede
this stand of rolls in which final size reductions are
made. Cooling water is used after rolling for cool-
ing the strip prior to coiling. Most hot-rolled strip
is pickled by passing the strip through solutions of
mineral acids and inhibitors. The strip is then
rinsed with water.
Much hot-rolled strip is further reduced in
thickness in cold rolls in which the heat generated
by working the metal is dissipated by water sprays.
Palm oil or synthetic oils are added to the water
for lubrication. After cold reduction, the strip is
often cleaned by using an alkaline wash and rinse.
Tin plate is made from cold-rolled strip by either
an electrolytic or hot-dip process, most commonly
by the former. The electrolytic process consists of
cleaning the strip using alkaline cleaners, rinsing
with water, light pickling, rinsing, plating, rinsing,
heat treating, cooling with water (quenching),
drying, and coating with oil. The galvanizing or
coating of steel strip with various other products
is carried out basically by the same general scheme
as tinning.
The volume of water used in the manufacturing
of steel is a variable which depends on the quantity
and quality of the available supply. The quantity
presently being used varies from a minimum of
about 1,500 gal/ton of product, where water is
reused intensively, to about 65,000 gal/ton, where
water is used on only a once through basis. Both
of these figures include total water utilized, not
just process water. These figures contrast the range
of water intake between plants in areas having:
(1) extremely limited, and (2) almost unlimited
water supplies.
The only definitive information available to the
task force on the amount of process water required
as compared with other water uses was found in
the census of manufacturers (7). The following is
a summary of this information for 1964 for the
steel industry (SIC 331).
Water use:
Volume, bgy
Intake water
Process water _.
Cooling
Boiler feed, etc..
4,051
885
3,008
159
This tabulation indicates that only 22 percent
of the water taken into a steel plant is termed
process water. Representatives of the industry
have indicated that process water may account
for as much as 30 to 40 percent of the total water
intake.
Recycling of water is receiving much attention
from the industry as a method to reduce water
utilization, reduce stream pollution, and minimize
the cost of controlling this pollution. Although in-
dividual plants within the iron and steel industry
have been practicing reuse of water to varying
degrees for some years, the major changes are yet
to come. According to the Census of Manufac-
tures, the gross water used in the industry in 1964
was approximately 5,800 billion gallons. This
gross water use when compared with a water
intake of about 4,000 billion gallons indicates
that 1,800 billion gallons were reused. This quan-
205
-------
tity reflects total water reuse not just of process
water. The consumption of water'by the industry
amounted to approximately 240 billion gallons in
1964. No corresponding calculation may be made
at this time for process water only because no
data on process water discharge are available.
Significant indicators of water quality
The water quality indicators which will be con-
sidered are settleable, suspended, and dissolved
solids, acidity and alkalinity, hardness, pH, chlo-
rides, dissolved oxygen, temperature, oil, and
floating material. In the judgment of the task
force, this short list incudes those process water
qualities that are considered important to the
industry.
The quality of surface waters that are being
utilized by the iron and steel industry varies con-
siderably from plant to plant. Ranges of values for
the selected quality characteristics for existing
supplies are listed in table V-16. The quality of
the water available has been much less important
than the quantity in determining where a steel mill
should be built and even severe limitations on
water availability have not precluded the building
of new mills where the controlling economic
factors were considered favorable.
TABLE V-16. Quality Characteristics of Surface
Waters That Have Been Used by the Iron and
Steel Industry (SIC 33)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum values
shown.]
Characteristics
Settleable
solids _ -
Suspended
solids
Dissolved
solids
Acidity,
(CaC03)
Alkalinity
(CaC03)
Concen-
trations
350
3,000
1,500
75
200
Characteristics
Hardness
(CaC03)
pH, units
Chloride (Cl)_
Temperature, F_
Organics, carbon
tetrachloride
extractables
Concen-
trations
1,000
3-9
500
100
30
NOTE.—Application of the above values should be based on
Part 23, ASTM book 9f standards (1), or APHA Standard
methods for the examination of water and wastewater (5).
The desired quality of water for various process
use in the iron and steel industry is difficult to
define. For a few processes, using relatively small
quantities of water, limits on some constituents
are known. For most of the process water used,
however, only a few of the water quality char-
acteristics have been recognized as a cause of
operational problems. For the other characteristics
or properties neither the technological nor eco-
nomical limits are known.
Water treatment processes
Most integrated steel plants have two or more
process water systems. One system is the general
plant water supply. It receives only mechanical
skimming and straining for control of floating and
suspended materials which could harm pumps and
possibly internal conditioning. This water is used
for such diverse tasks as coke quench, slag
quench, gas cleaning, and in the hot rolling opera-
tions. For some of these operations, many mills
use effluent from another process or recycle water
in the same process and the water might actually
be of very poor quality. However, the only limits
for these process uses which could be established
based on present knowledge are those listed in
tableV-17.
The other process waters used by the steel in-
dustry comprise only 2 to 5 percent of the total
volume- but often require considerably improved
quality. Almost universally, one of these two im-
proved supplies is clarified while the second is, in
addition, either softened or demineralized.
The clarified water is usually a coagulated,
settled, and filtered supply that is either treated by
the steel company or purchased from a municipal-
ity. The use for this water is mainly in the cold
rolling or reduction mill where surface properties
of the product are particularly important.
The softened or demineralized water is required
for rinse waters following some pickling and
cleansing operations. The more particular proc-
esses from a water quality point of view are the
coating operations such as tin plating, galvanizing,
organic coating, etc. Some plants use^softened and
others demineralized water for identical purposes.
The quality limits desired for these two types of
water, softened and demineralized, are given in
table V-17. The quantity of these waters required
is less than 1 percent of the total process water
supply.
206
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TABLE V-17. Quality Requirements of Water at Point of Use for the Iron and Steel Industry
(SIC 33)
[Unless otherwise indicated, units are mg/1 and values that normally should not be exceeded. Quality of water prior to the addition
of substances used for internal conditioning.]
Characteristics
Settleable solids
Suspended solids
Dissolved solids
Alkalinity (CaCOa)
Hardness (CaCO3)
pH, units _ _ _
Chloride (Cl)
Dissolved oxygen (Oz)
Temperature, F
Oil
Floating material
Quenching,
hot rolling,
gas cleaning
100
O
O
(3)
(3)
5-9
O
O
100
C)
Selected rinse waters
Cold rolling
10
0
0
5-9
O
O
100
O
0
Softened
O
O
O
O
100
6-9
9
100
O
O
Demineralized
9
o
9
o
o
100
O
O
1 Accepted as received (if meeting total solids or other 4 Minimum to maintain aerobic conditions.
limiting values); has never been a problem at concentrations 5 Concentration not known.
2 Zero not detectable by test NOTE.—Application of the above values should be based
• Controlled by treatment for'other constituents. on f>art 2.3- ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater, (5).
207
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food canning industry
(SIC's 2032 and 2033)
iption of industry
Part VI.
food
and kindred
and leat
products
ier
and leather products
(SIC's 20 and 31)
Nearly 2,000 canneries make up the Nation's
canning industry. These are located in 49 of the
50 States, Puerto Rico, and the Virgin Islands.
These plants produce all of the basic canned food.s
—vegetables, fruits and fruit juices, milk, meat,
seafoods, soups, and infant foods, as well as nu-
merous specialties and combinations. More than
1,200 different canned items and combinations
are made available from the production of these
canneries. The 1965 pack of canned foods was
more than 765 million cases containing over
27 billion tin and glass containers divided among
these main categories: seasonal vegetables, 227
million cases; fruits, 124 million cases; juices, 114
million cases; milk, 44 million cases; fish, 3 million
cases; canned meat, 46 million cases.
Processes utilizing water
One of the most important operations in com-
mercial canning is thorough cleaning of the raw
foods. The procedures of cleaning vary with the
nature of the food; but all raw foods must be freed
of adhering soil, dried juices, insects, and chemical
residues. This is accomplished by subjecting the
raw foods to high-pressure water sprays while
being conveyed on moving belts or passed through
revolving screens. The product wash water may be
fresh or reclaimed from an in-plant operation, but
it must be of potable quality.
Washed raw products are transported to and
from the various operations by means of belts,
flumes, and pumping systems. This is a major use
of water. Although the fresh water makeup must
be of potable quality, recirculation is practiced to
reduce water intake. Chlorination is used to main-
tain recycled waters in a sanitary condition.
A third major use of water is for rinsing chem-
ically peeled fruits and vegetables to remove excess
peel and caustic residue. Water of potable quality
must be used.
Green vegetables are immersed in hot water
or exposed to live steam in blanching operations
to inactivate enzymes and to wilt leafy vegetables
to facilitate their filling into cans or jars. The
208
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WATER
RAW PRODUCT
WASHING
GRADING,
TRIMMING
PEELING,
PITTING,
CUTTING
RINSING,
PLUMING
BLANCHING,
CONCENTRA-
TING
FILLING,
SEALING
EXHAUSTING,
PROCESSING
COOLING
CLEANING,
WASTE
PLUMING
SOLID
WASTE
CANNED
PRODUCT
blanch waters are recirculated, but makeup waters
must be of potable quality. Steam generation,
representing about 15 percent of water intake,
when used for blanching or injection into the prod-
uct must be produced from potable waters, free of
volatile or toxic compounds. Syrup, brine, or water
used as a packing medium must be of high quality
and free of chlorine.
After heat processing, the cans or jars are
cooled with large volumes of potable water. This
water must be chlorinated to prevent spoilage of
the canned foods, by microorganisms in case that
cooling water is aspirated during formation of a
vacuum in the can.
A final significant use of water is for transport-
ing from the cannery, the inedible product, spil-
lage, and trimmings that are discarded as waste.
A flow sheet showing the various uses of water
and origin of waste streams is attached as figure
V-3.
Most fruit and vegetable canning, as opposed to
canning of specialty products, is highly seasonal.
The demand for water may vary 100 fold among
months of the year. The water-demand variation
may be several fold even for plants that pack sub-
stantial quantities of nonseasonal items.
The gross quantities of water used per ton of
product vary widely among products, among can-
neries, and among years in the same cannery. The
proportion of gross water supplied by recirculation
has increased over the years and the trend is ex-
pected to continue. A tendency has been noted to
use more water per ton of product as the propor-
tion of recirculated water increases. The consump-
tive use of water is also expected to increase with
recirculation.
The following tabulation gives the fate of gross
water intake as based on the 1963 census of
manufacturers (7) for canning plants having an
annual water intake of 20 or more million gallons.
Item
Intake
Reuse
Consumption
Discharge
Water quantity
(bgy)
- - 48
18
4
44
Percent of
intake quantity
100
37
8
92
LIQUID WASTE
Figure V-3-Uses of water and steam in canning.
A breakdown of the quantities and percentages
of the total water used in the various process oper-
ations based on data from the National Canners
Association is as follows:
209
-------
In-plant use Water quantity
(bgy)
Raw product washing .
Product transport *
Product preparation 2
Incorporation in product3-—
Steam and water sterilization
of containers
Container cooling
Plant cleanup
9.9
6.6
6.6
4.0
9.9
23.7
5.3
Percent
of total use
15
10
10
6
15
36
8
1 Pluming and pumping of raw product.
2 Blanching, heating, and soaking of product.
3 Preparation of syrups and brines which enter
the container.
Significant indicators of water quality
Of the 48 billion gallons of water intake for the
two groups (canned and cured seafoods and
canned fruits and vegetables), 24 billion gallons
were drawn from public water supplies and more
than 20 billion gallons from ground sources. Ap-
proximately 4 billion gallons came from surface
water supplies.
The quality of raw surface waters for use in the
food canning industry should be that prescribed
by the NTA Subcommittee on Water Quality
Criteria for Public Water Supplies, in this volume.
Table V-18 has been prepared to indicate the
quality characteristics of raw waters that are now
TABLE V-18. Quality Characteristics of Surface
Waters That Have Been Used by the
Food Canning Industry
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded.]
Characteristic
Alkalinity (CaCO3)
pH, units
Hardness
(CaCOi)
Calcium (Ca)
Chlorides (Cl) ___
Sulfates (SO4) __-
Iron (Fe)
Manganese (Mn)_
Silica (Si02),
dissolved
Phenols
Nitrate (N0rt)
Nitrite (N02)
Concen-
tration
300
8.5
310
120
300
250
0.4
0.2
50
O
45
O
Characteristic
Fluoride (F)
Organics: Carbon
chloroform
extract
Chemical oxygen
demand (O2)
Odor, threshold
number
Taste, threshold
number
Color, units .
Dissolved solids
Suspended solids.
Coliform,
count/100 mi-
1 As specified by NTA Subcommittee on Water
Criteria for Public Water Supplies, in this volume.
ce ncen-
tration
O
0.3
O
C)
O
550
12
C)
Quality
2 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
3 Zero, not detectable by test.
NOTE.—Application of the above values should be based
on Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater, (5).
being treated for use as process waters in food
canning plants. The values are drawn from limited
data and the procedures and costs of treating the
raw waters are not available at this time. The
values given are not intended to imply that better
quality waters are not desirable or that poorer
quality waters could not be used in specific cases.
Significant water quality requirements for water
at point of use are given in table V-19.
TABLE V-19. Quality Requirements of Water at
Point of Use by the Canned, Dried, and
Frozen Fruits and Vegetables Industry
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded. Quality of water prior to the
addition of substances used for internal conditioning.]
Canned specialities (SIC 2032)
Canned fruits, vegetables, etc. (SIC 2033)
Dried fruits and vegetables (SIC 2032)
Characteristic Frozen fruits and vegetables (SIC 2037)
Acidity (HaSOO 0
Alkalinity (CaCO3) 250
pH, units 6.5-8.5
Hardness (CaCO3) 250
Calcium (Ca) 100
Chlorides (Cl) 250
Sulfates (S04) 250
Iron (Fe) 0.2
Manganese (Mn) 0.2
Chlorine (Cl) C)
Fluorides (F) 1!
Silica (SiO2) 50
Phenols ("•4)
Nitrates (NO3) 10"
Nitrites (NO2) C)
Organics:
Carbon tetrachloride 0.2'
Odor, threshold number... O
Taste, threshold number__ (3)
Turbidity (")
Color, units 5
Dissolved solids 500
Suspended solids 10
Coliform, count/100 ml (6)
Total bacteria, count/100 mL_ (')
1 Process waters for food canning are purposely chlorinated
to a selected, uniform level. An unchlorinated supply must
be available for preparation of canning syrups.
2 Waters used in the processing and formulation of foods
for babies should be low in fluorides concentration. Because
high nitrate intake is alleged to be involved in infant illnesses,
the concentration of nitrates in waters used for processing
baby foods should be low.
3 Zero, not detectable by test.
4 Because chlormation of food processing waters is a desir-
able and widespread practice, the phenol content of intake
waters must be considered. Phenol and chlorine in water
can react to form chlorophenol, which even in trace amounts
can impart a medicinal off flavor to foods.
5 Maximum permissible concentration may be lower depend-
ing on type of substance and its effect on odor and taste.
°As required by USPHS drinking water standards, 1962 (8).
7 The total bacterial count must be considered as a quality
requirement for waters used in certain food processing
operations. Other than esthetic considerations, high bacterial
concentration in waters coming in contact with frozen foods
may significantly increase the count per gram for the food.
Waters used to cool heat-steril'zed cans or jars of food must
be low in total count for bacteria to prevent serious spoilage
due to aspiration of organisms through container seams.
Chlorination is widely practiced to assure low bacterial counts
on container cooling waters.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater, (5).
210
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Water treatment processes
Processes utilizing water
Where used by the food canning industry, sur-
face waters will require treatment before use as
process waters. Usually, this treatment involves
coagulation, sedimentation, filtration, and disinfec-
tion. More extensive treatment may be required
for those waters incorporated in the product.
Container cooling waters are routinely treated
by heavy chlorination to render them free of sig-
nificant types of bacteria. Waters used for washing
and transporting raw foods are generally chlori-
nated particularly if all or a portion of the water is
recirculated. In some cases, waters in which vege-
tables are blanched, may require treatment to
reduce hardness.
bottled and canned
soft drinks (SIC 2086)
Description of industry
While essentially local in nature, the soft drink
industry is national in character because it operates
on a franchise system. A soft drink franchise grants
the right to produce and distribute a specific
beverage in a certain area.
There has been a marked reduction in the num-
ber of producing plants—from 5,469 in 1954 with
a production of 1,176,674,000 cases to 3,619 in
1965 with a production of 2,104,282,000 cases.1
It is obvious that numerous small plants have
been discontinued as producing units. This trend is
likely to continue in future years.
1 A case is defined as 24 bottles containing 8 ounces
of beverage. In the above figures, bottles larger or smaller
than 8 ounces have been converted to 8-ounce equiva-
lents. Data obtained from National Soft Drink Associa-
tion, 1128 16th Street, NW, Washington, D.C.
In the production of soft drinks, water is used
not only in the finished product itself but also for
the following purposes:
—Washing containers.
—Cleaning production equipment.
—Cooling refrigeration and air compressors.
—Plant clean up.
—Truck washing.
—Sanitary purposes (restrooms and showers).
—Lawn watering.
—Low-pressure heating boilers.
—Air conditioning.
Water quantity utilized by each process is esti-
mated as:
Intake—approximately 25 bgy.
Recycle—6 bgy.
Consumption—3 bgy.
Discharge—22 bgy.
A comprehensive survey of the quantity of water
intake and reuse has not been made. The 1963
census of manufacturers (7) lists the total water
intake of bottled and canned soft drinks as 6 bil-
lion gallons. However, this quantity is the amount
used by only 114 of the largest plants whose water
intake was 20 or more million gallons per year.
This is less than 3 percent of the total number of
plants. The 1963 census does not give the total
quantity of beverage produced by the 114 plants,
so the water usage data cannot be extrapolated to
give an estimate of the total industry usage.
The figure of 25 billion gallons intake is based
upon production of 2.1 billion cases per year and
an average of 12 gallons of water used per case.
The figure of 12 gallons per case came from the
limited data now available.
The 1963 census of manufacturers (7) lists the
gross water usage, including recycle, as 8 billion
gallons and total water intake as 6 billion gallons.
There is no similar data for the entire industry.
However, the reuse of water within the industry has
for some years increased and is still increasing as
the older and smaller plants are replaced by new
and larger plants which use recirculating rather
than once through cooling water equipment, mod-
ern bottle washers which use less water per case
washed than does older equipment, and other
water reuse devices.
The consumption figure of 3 billion gallons is
based upon the water content of the total quantity
of beverage produced in 1965.
The discharge figure of 22 billion gallons is the
difference between the estimated 25 billion gallons
of intake and the 3 billion gallons of product
water.
211
-------
Significant indicators of water quality
Water which is mixed with flavoring materials
to produce the final product must be potable. Like-
wise, potable water is needed for washing fillers,
syrup lines, and other product handling equip-
ment. The water used for washing product con-
tainers must also be potable.
Although other water uses do not require po-
tability, it has not been customary to use non-
potable water for any purpose in a soft drink plant.
The water which becomes a part of the final
product must not only be potable, but must also
contain no substances which will alter the taste,
appearance, or shelf life of the beverage. Because
beverages are made from many different syrup
bases, the concentration and type of substances
which affect taste, or other characteristics, are not
the same for all beverages. For this reason a single
standard cannot apply to all types of soft drinks.
This is the conclusion reached by the water treat-
ing committee of the Society of Soft Drink Tech-
nologists after conducting a survey of the water
composition required by the various franchise
companies.
The majority of plants use only water from a
public supply. Some use water from private wells.
None use water directly from surface sources.
Hence, the quality characteristics for intake water
are the same as quality requirements for potable
water.
Uniformity of water composition is most de-
sirable. Control of in-plant processing is difficult
when the composition of the water varies from
day to day. Surface waters which are subject to
heavy biological growths or heavy pollution with
organic chemicals are also difficult to process.
Except for process water, most public water
supplies are suitable without external treatment
for all other usages. Occasionally, cation exchang-
ers are used to soften bottle washing, cooling, and
boiler feed water, but internal conditioning is used
in most plants for scale and corrosion control.
Water treatment processes involved
There are few, if any, public water supplies
which are suitable as product water without any
in-plant processing whatsoever. Almost 100 per-
cent of the bottling plants have a sand filter and an
activated carbon purifier. About 80 percent of the
plants also coagulate and super-chlorinate the
water preceding sand filtration and carbon purifi-
cation. When the total alkalinity of the intake water
is too high, lime is used to precipitate the alkaline
salts.
There are very few bottling plants whose intake
water is so highly mineralized that the brackish
taste affects soft drinks. This is due to several
facts: flavoring components in soft drinks mask
the taste of salts so that many waters which taste
brackish do not alter the taste of soft drinks; towns
with highly mineralized water supplies are avoided
as locations for bottling plants or suitable private
supplies are used.
TABLE V-20. Quality Requirements of Water at
Point of Use by the Soft Drink Industry
(SIC 2086)
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded. Quality of water prior to the
addition of substances used for internal conditioning.]
Characteristic
Alkalinity (CaC03)
pH, units
Hardness
(CaCO,)
Chlorides (Cl)
Sulfates (SO4)--
Iron (Fe)
Manganese (Mn)
Concen-
tration
85
C)
O
500 2
500 2
0.3
0.05
Characteristic
Fluoride (F) _
Total dissolved
solids
Organics, CCE
Coliform bacteria-
Color, units
Taste . _
Odor
Concen-
tration
O
O
0.2 *
10 4
(4, 5)
1 Controlled by treatment for other constituents.
2 If present with equivalent quantities of Mg and Ca as sul-
fates and chlorides, the permissible limit may be somewhat
below 500 mg/l.
3 Not greater than USPHS Drinking Water Standards.
4 In general, public water supplies are coagulated, chlori-
nated, and filtered through sand and granular activated carbon
to insure very low organic content and freedom from taste and
odor.
5 Zero, not detectable by test.
NOTE.—Application of the above values should be based on
Part 23, ASTM book of standards (1), or APHA Standard
methods for the examination of water and wastewater (5).
212
-------
Significant indicators of water quality
The chemical composition of the water is im-
portant in producing high quality leather. For
some processes, such as the finishing of leather,
distilled or demineralized water is best. The
microbiological content of the water is equally
important, but this can be controlled by use of
disinfectants. The quality requirements at point
of use are shown in table V-2 1 .
tanning industry
(SIC 3111)
Water treatment processes
Most tanning and leather product industries are
located in urban areas and use public water sup-
plies or ground water. A few tanneries use surface
supplies. Such waters are usually chlorinated.
They may also need additional treatment, such as
clarification and iron and manganese removal.
A limited volume of water, whether from the
public water supply or company-owned systems,
may be softened, distilled, or demineralized.
Description of industry
The tanning-leather industry is many industries
as each type of leather constitutes a different
process. Basically there are only three or four
types of tannage (vegetable, mineral, combination
of vegetable-mineral, and syntans) but many
finishing processes.
Processes utilizing water
Water is used in all processes of storage, sorting,
trimming, soaking, green fleshing, unhairing,
neutralizing, bating, pickling, tanning, retanning,
fat-liquoring, drying and finishing of the hides.
It is an essential factor in each process. The chemi-
cal composition of the water is considered critical
in obtaining the desired quality of leather. For this
and other reasons there is little reuse of water in
the tanning industry.
The following tabulation gives data on water
utilization by the leather tanning and finishing in-
dustry as reported in the 1963 census of manu-
facturers (7).
Water use:
Water quantity,
bgy
Intake 15.
Reuse Negligible.
Consumption do.
TABLE V-21. Quality Requirements of Water
at Point of Use by the Leather Tanning and
Finishing Industry (SIC 3111)
[Unless otherwise indicated, units are mg/l and values that
normally should not be exceeded. Quality of water prior to the
addition of substances used for internal conditioning.]
Characteristic
Alkalinity (CaCO3)
pH, units -
Hardness (CaCO3)
Calcium (Ca) _ _
Chloride (Cl)
Sulfate (SOO
Iron (Fe) , ,
Manganese (Mn)
Organics: Carbon
chloroform extract--
Color, units
Coliform bacteria
Turbidity _ _ _
Tanning
processes
o
6080
150
60
250
250
50
O
O
5
(")
O
General
finishing
processes
o
6.0-8.0
O
O
250
250
0.3
0.2
0.2
5
(")
O
Coloring
o
6 0-8.0
(3, 4)
(3, 4)
(E)
C)
0.1
0.01
o
5
(«)
(3)
1 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
2 Lime softened.
3 Zero, not detectable by test.
* Demineralized or distilled water.
5 Concentration not known.
0 1962 U.S. Public Health Service Drinking Water Standards,
Pub. 956 (8).
NOTE.—Above values based on Part 23, ASTM book of
standards (1); APHA standard methods for examination of
water and wastewater, (5).
213
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Part VII.
cement industry
(SIC 3241)
TABLE V-22. Quality Characteristics of Surface
Waters That Have Been Used by the Hydraulic
Cement Industry (SIC 3241)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum values
shown.]
Characteristic
Acidity (CaCO3)
Alkalinity
(CaC03)
Chemical oxygen
demand
(02)
Coliform bac-
teria (count/
100 ml)
Color, units
Hardness
(CaCO3)
Calcium
hardness
(CaCO3)
Concen-
tration
C)
240
O
o
(2)
500
150
Characteristic
Iron (Fe)
Manganese
(Mn)
Organics:
Carbon
tetrachloride
extract
pH, units
Silica (SiO2)—
Dissolved
solids _ _
Suspended
solids
Sulfate (SOO--
Chloride (Cl) ._
Concen-
tration
1.8
5
1
6.9-8.8
16
1,120
200
235
100
1 Zero, not detectable by test.
2 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
NOTE.—Concentrations are based on limited data. Applica-
tion of the above values should be based on Part 23 ASTM
book of standards (1) or APHA Standard methods for the
examination of water and wastewater (5).
About 58 percent of current cement manufac-
ture is by the wet process requiring an estimated
16bgy (1966).
Quality requirements for process water in the
cement manufacturing industry are not rigorous,
although they are somewhat more restrictive than
those of mixing water for concrete. Surface and
ground waters and public water supplies are used.
Treatment is usually not required.
A listing of the quality of surface waters that
have been used is presented in table V-22. Quality
requirements for water at point of use for the
hydraulic cement industry are indicated in table
V-23.
TABLE V-23. Quality Requirements of Water at
Point of Use for the Hydraulic Cement Industry
(SIC 3241)
[Unless otherwise indicated, units are mg/l and values are
maximums. No one water will have all the maximum values
shown. Quality of water prior to addition of substances used
for internal conditioning.]
Characteristic
Acidity
(CaC03)
Alkalinity
(CaCO3)
Chemical oxygen
demand
(O2)
Coliform bac-
teria, (count/
100 ml)
Color, units
Hardness
(CaCOs)
Calcium
hardness
(CaC03)
Concen-
tration
(l)
400
(•)
O
O
(2)
0
Characteristic
Organics:
Carbon
tetrachloride
extract
Iron (Fe)
Manganese
(Mn)
pH, units
Silica (SiO2) „
Dissolved
solids
Suspended
solids
Sulfate (SO,)-_
Chloride (Cl) _.
Concen-
tration
1
25
0.5
6.5-8.5
35
600
500
250
250
iZero, not detectable by test.
3 Accepted as received (if meeting total solids or other
limiting values); has never been a problem at concentrations
encountered.
NOTE.—Concentrations are based on limited data. Applica-
tion of the above values should be based on Part 23, ASTM
book of standards (1) or APHA Standard methods for the
examination of water and wastewater (5).
214
-------
(1) AMER. Soc. FOR TESTING AND MATERIALS BOOK OF
STANDARDS PART 23. 1966. Amer. Soc. for Test-
ing and Materials, Philadelphia, Pa.
(2) NEBOLSINE, R. 1954. Water Supply for Steel
Plants. Iron and Steel Engineer 31(4): 78-88.
(3) OHIO RIVER VALLEY WATER SANITATION COM-
MISSION. 1967. ORSANCO Stream-Quality Cri-
tena anc* Minimum Conditions. Ohio River
Valley Water Sanitation Commission, Cincinnati,
Ohio.
(4) OTTS, L. E., JR. 1963. Water Requirements of
the Petroleum Industry, Geological Survey Water-
Supply Paper 1330-G, U.S. Government Printing
Office, Washington, D.C.
(5) AMER. PUB. HEALTH Assoc., AMER. WATER
WORKS ASSN., WATER POLLUTION CONTROL FED-
ERATION. 1965. Standard Methods for the
Examination of water and Wastewater. Amer.
Pub. Health Assn., Inc., 1790 Broadway, New
York, N.Y. 10019.
(6) U.S. BUREAU OF THE BUDGET. 1963. Office of
Statistical Standards, Technical Committee on
Industrial Classification. Standard Industrial
Classification Manual, 1957, as amended to 1963.
(7) U.S. DEPARTMENT OF COMMERCE. 1966. 1963
Census of Manufacturers, Water Use in Manu-
facturing. MC63(1)-10. U.S. Government Print-
ing Office, Washington, D.C. 20402.
(8) U.S. DEPARTMENT OF HEALTH, EDUCATION, AND
WELFARE. 1962. Public Health Service Drinking
Water Standards. Public Health Service Publi-
cation 956. U.S. Government Printing Office
Washington, D.C. 20402.
(9) U.S. SENATE, 86TH CONGRESS, SECOND SESSION,
SELECT COMMITTEE ON NATIONAL WATER RE-
SOURCES. 1960. Water Resources Activities in
the United States, Electric Power in Relation to
the Nation's Water Resources Committee Print.
No. 10, U.S. Government Printing Office, Wash-
ington, D.C.
215
-------
-------
index
NOTE. page numbers in italics indicate information is to be found in tables.
ABS see Alkylbenzene sulfonates
Absorption see Foliar absorption
Acidic soils
humid areas, p. 174
humid climates, p. 172
supplemental irrigation, p. 174
Acidity
alkalinity—pH recommendation, p. 40
irrigation water, p. 155
Acrolein
irrigation water, p. 158
Activated carbon
water purification, p. 129
Adsorption
oil, p. 72
soil chemical properties, p. 173
see also Sodium adsorption ratio
Aeration
supplemental irrigation, p. 175
water purification, p. 128, 129
water treatment, p. 128, 129
Aesthetics
national goal, p. 5
surface waters, p. 3
water quality, p. 3
water quality recommendations, p. 5, 6
Aldrin
toxicity, p. 37, 83
Algae
beneficial role, p. 51
bioassay, p. 57
chemical composition, p. 55
fresh water, p. 51
mortality effects, p. 52
nutrients, p. 51
photosynthetic affect, p. 53
recommendation on nuisance growth, p. 56
species description, p. 51
stock water, p. 137
toxins, p. 53
see also Phaeophyta
Algal control
heavy metals, p. 61
Algal poisoning
stock water, p. 137
Algal toxins, p. 52
Algicides
fresh water recommendation, p. 63
median tolerance limit, p. 64
Alkaline soils
humid areas, p. 174
supplemental irrigation, p. 174
Alkalinity
acidity-—pH recommendation, p. 40
irrigation water, p. 155
public water supplies, p. 22
waterfowl, p. 94
Alkalinity (Cont'd)
wildlife, p. 38
Alkylbenzene sulfonates
effect on aquatic life, p. 65
fresh water, p. 35
median tolerance limit, p. 65
toxicity, p. 65
see also Methylene blue active substances
Aluminum
phytotoxicity, p. 152
Amitrole-T
irrigation water, p. 158
Ammonia
chlorine reaction, p. 22
fresh water bioassay, p. 65
pollutants, p. 22
public water supplies, p. 22
toxicity—fresh water, p. 65
toxicity—sea water, p. 88
water pollution, p. 22
Anabaena, p. 137
chemical composition, p. 55
Anacystis, p. 137
Anadromous fish
spawning migration, p. 31
Anaerobic conditions
sea water, p. 77
Animal diseases
livestock, p. 132, 133
waterborne, p. 132
wildlife, p. 98
Animal parasites
flukes, p. 141, 142
livestock, p. 141
water pollution sources, p. 141
Animal wastes (wildlife)
fecal coliforms, p. 12
fecal streptococci, p. 12
primary contact recreation waters, p. 12
Aphanizomenon, p. 137
chemical composition, p. 55
Application methods
irrigation water, p. 169, 170
Aquatic algae
nutrients, p. 51
Aquatic environment
monitoring problems, p. 82
pesticides, p. 82
radioisotopes, p. 49
Aquatic habitats
nuisance growth, p. 51
water temperature, p. 42
see also Waterfowl
Aquatic life
acidity, alkalinity and pH recommendation, p. 40
biochemical oxygen demand, p. 57
carbon dioxide, p. 44
217
-------
Aquatic life (Cont'd)
chemical oxygen demand, p. 57
cold water fish, p. 33
currents, p. 35
dissolved oxygen—fresh water, p. 33
dissolved solids recommendation, p. 40
floating materials, p. 48
fresh water pH alkalinity, acidity, p. 32
fresh water temperature effects, p. 32
introduction to Subcommittee report, p. 29
marine and estuarine, p. 35
radioactive wastes, p. 49
salinity, p. 35
spawning migration, p. 31
Subcommittee report, p. 28-110
summary of recommendations, p. 32
toxic substances, p. 56
turbidity, p. 47
warm water fish, p. 32
zones of passage, p. 31
Aquatic plants
emersed plants and nutrients, p. 52
floating plants and nutrients, p. 53
light penetration, p. 96
marginal plants and nutrients, p. 52
nuisance organisms and nutrients, p. 51
nutrients and nuisance organisms, p. 78
recommendation on nuisance growth, p. 56
rooted plants and nutrients, p. 53
salinity fluctuation effects, p. 95
submerged plants and nutrients, p. 52
Aquatic weeds
nuisance growth, p. 53
nutrients, p. 53
Arid climates, p. 167
Arid lands
humid areas, p. 172
soil chemical properties, p. 173
Arkansas River Basin
dissolved solids, p. 168
Arsenicals (pesticides)
toxicity, p. 37
toxicity—livestock, p. 135
Arsenic compounds
phytotoxicity, p. 152
toxicity—sea water, p. 85-86
Ascaris
irrigation water, p. 161, 162
Aspergillosis
prevention, p. 38
Asterionella
phosphorus, p. 55
Bacillary hemoglobinuria
epidemiology, p. 139
waterborne diseases, p. 139
water pollution effects, p. 139
Bacillus anthracis, p. 139
Back Bay, Va.
silts, p. 96
Bacteria
farmstead water supplies—nonpathogenic, p. 123
fresh water, p. 51
nuisance-type growth, p. 51
Sphaerotllus, p. 51
stock water, p. 138
see also Psychrophilic bacteria
Barriers
zones of passage, p. 31
Benthic flora
ecosystem indicator, p. 54
nutrients, p. 54
Beryllium
phytotoxicity, p. 153
BHC
toxicity, p. 37, 83
Bicarbonates
alkalinity—waterfowl habitat, p. 94
phytotoxicity, p. 156
Bioassay
algae, p. 57
dissolved solids, p. 40
industrial wastes, p. 37
oils, p. 46
seawater, p. 80
toxicity, p. 35, 58
waste treatment, p. 37
Biochemical oxygen demand (BOD)
aquatic life, p. 57
farm wastes, p. 132
irrigation water, p. 118, 166
pulp wastes, p. 90
Sphaerotilus, p. 51
supplemental irrigation, p. 175
Biodegradation
application factor, p. 37
Bioindicators
fish, p. 115
stock water, p. 115, 131,131
Biological magnification
water pollution, p. 81
Biological terms see Glossary
Boating
recreation, p. 8
waste water (pollution), p. 91
BOD see Biochemical oxygen demand
Boiler feed water, p. 191
demineralization, p. 193
heat exchanger, p. 792
industrial water, p. 187, 188, 188, 194
separation techniques, p. 193
water consumption, p. 191, 192
water properties, p. 189, 190, 194
water quality, p. 191, 194
water purification, p. 193
water softening, p. 193
water treatment, p. 193
Boilers, p. 191
BOR see Bureau of Outdoor Recreation
Boron
phytotoxicity, p. 153, 153
public water supplies, p. 23
Botanicals
toxicity, p. 37
Botulism
waterfowl, p. 93
wildlife transmission prevention, p. 38
Brackish water
color, p. 75
cooling water, p. 193
Brown algae see Phaeophyta
Bureau of Outdoor Recreation
recreation, p. 7, 8
Cadmium
phytotoxicity, p. 153
toxicity—fresh water, p. 61
toxicity—sea water, p. 86
218
-------
Calcium carbonate
cause of acidity, p. 41
hardness (water), p. 41
California river systems
dissolved solids, p. 168
Canneries
chlorination, p. 210, 211
food cleaning, p. 208
surface waters, p. 210
waste water (pollution), p. 209
water consumption, p. 209, 210
water properties, p. 210
water purification p. 211
water quality requirements, p. 210
water utilization, p. 208, 209
Canning, p. 208, 209
Carassius carassius
oil, p. 45
Carbamate pesticides
toxicity, p. 37
Carbonated beverage industry
food industry, p. 211
potable water, p. 212
water consumption, p. 211
water properties, p. 212
water quality requirements, p. 272
water treatment, p. 212
water utilization, p. 211
Carbon chloroform extract
farmstead water supplies, p. 124
public water supplies, p. 24, 25
Carbon dioxide
aquatic life, p. 44
excess of "free", p. 44
fresh water, p. 33
marine and estuarine organisms, p. 68
recommendations, p. 45
respiratory effects, p. 44
temperature and oxygen relationship, p. 45
Carcinogenic substances
oil polluted waters, p. 73
Carnivores
pesticide residues, p. 81
Catadromous fish
spawning migration, p. 31
Cattle
saline water tolerance, p. 134
CCE see Carbon chloroform extract
Cement industry
surface waters, p. 214
water properties, p. 214
water quality requirements, p. 214
water utilization, p. 214
Chara
chemical composition, p. 55
Chemical industry
industrial water, p. 187
surface waters, p. 207
water consumption, p. 188, 201
water properties, p. 207
water purification, p. 200
water quality requirements, p. 200
water treatment, p. 200
water utilization, p. 200
Chemical oxygen demand (COD)
aquatic life, p. 57
irrigation water, p. 166
pulp wastes, p. 90
Chlordane
toxicity, p. 37, 83
Chlorides
irrigation water, p. 117
phytotoxicity, p. 155
Chlorinated hydrocarbon pesticides
farmstead water supplies, p. 125
fresh water recommendation, p. 63
public water supplies, p. 25
toxicity, p. 37
Chlorination
canneries, p. 210, 211
farmstead water supplies, p. 127
water purification, p. 127, 128
water treatment, p. 18, 127, 128, 129
Chlorine
ammonia reaction, p. 22
psychrophilic bacteria, p. 123
Chromium
phytotoxicity, p. 153
toxicity of hexavalent-fresh water, p. 61
toxicity—sea water, p. 86
Cladophora
chemical composition, p. 55
Climate
irrigation efficiency, p. 145
Clostridia, p. 140
Coal, p. 205
Cobalt
phytotoxicity, p. 153
COD see Chemical oxygen demand
Coke, p. 205
Cold water fish, p. 33
dissolved oxygen, p. 33, 43, 44
water temperature, p. 43
Coliforms
dairy sanitation requirements, p. 125, 126
irrigation water, p. 118
public water supplies, p. 20, 21, 22
shellfish, p. 37
waste waster (pollution), p. 92
see also Fecal coliforms
Color
brackish water, p. 75
determination, p. 48
dissolved oxygen, p. 48
farmstead water supplies, p. 116, 124
fresh water, p. 34, 48
light intensity, p. 48
origin and definition, p. 48
photosynthetic oxygen, p. 48
public water supplies, p. 20, 21
recommendation, p. 48
restriction on light penetration reducers, p. 48
sea water, p. 74
spectroradiometer, p. 76
tainting substances, p. 77
see also Oil
Colorado River Basin
dissolved solids, p. 168
Columbia River Basin
dissolved solids, p. 168
Consumptive use
irrigation water, p. 169, 170
Cooling water, p. 191
brackish water, p. 193
demineralization, p. 193
fresh water, p. 193
heat exchangers, p. 792
industrial water, p. 187, 188,1S8,194
recirculated water, p. 191, 795
separation techniques, p. 795
219
-------
Cooling water (Cont'd)
water consumption, p. 192,193
water properties, p. 189,194
water purification, p. 193
water quality, p. 191,194
water softening, p. 193
water treatment, p. 193
Copper
farmstead water supplies, p. 123
phytotoxicity, p. 153
tainting substances, p. 77
toxicity—fresh water, p. 60
toxicity—sea water, p. 87
Copper compounds
sulfate concentration—irrigation water, p. 158
Coumaphos
toxicity, p. 37
Crop injury levels of herbicides
irrigation water, p. 118
Crops
irrigation effects, p. 144
salt tolerance, p. 148, 150
Crude oil see Oil
Crustaceans
pesticides, p. 82
Currents
aquatic life, p. 35
marine and estuarine organisms, p. 35, 68
Currituck Sound, N.C.
silts, p. 96
Cyanides
fresh water bioassay, p. 65
toxicity—fresh water, p. 65
toxicity—sea water, p. 88
Cyanophyta
livestock poisoning, p. 137
Cyclops
Nematodes, p. 142
2,4-D
irrigation water, p. 157, 759
Dairy products
water quality for cooling, p. 120
Dairy sanitation requirements
coliforms, p. 125, 126
farmstead water supplies, p. 116, 120, 121
hydrogen ion concentration, p. 124
Pasteurized Milk Ordinance, USPHS, p. 120
water quality criteria, p. 120, 121
Dalapon
irrigation water, p. 755
Daphnia magna
pH, p. 41,61,62, 64
Daphnia pulex, 61, 62, 64
DDT
irrigation water, p. 156
residues and wildlife, p. 97
toxicity, p. 37, 83
Deep wells
irrigation wells, p. 113
Definitions see Glossary
Defoliants
fresh water recommendation, p. 63
median tolerance limit, p. 64
Degradables see Alkylbenzene
sulfonates; Linear alkylate sulfonates
Demineralization
boiler feed water, p. 193
cooling water, p. 193
water treatment, p. 206
Detergents
permissible levels, p. 37
toxicity, p. 65, 88
Dichlobenil
irrigation water, p. 759
Dieldrin
toxicity, p. 37, 83
Dimethylamines
irrigation water, p. 759
Diquat
irrigation water, p. 755
Diseases see Animal diseases
Dissolved oxygen
botulism, p. 93
cold water fish, p. 33, 43, 44
color, p. 48
fish reproduction, p. 43
fresh water, p. 33
hypolimnion, p. 33, 44
irrigation water, p. 118
lakes, p. 44
marine and estuarine organisms, p. 36, 70
public water supplies, p. 23
recommendations, p. 44
reduction effects, p. 43
requirements by category, p. 43
salmonids, p. 44
streams, p. 44
tolerance variables, p. 44
warm water fish, p. 33, 43, 44
waterfowl, p. 93
wildlife, p. 38
Dissolved solids
Arkansas River Basin, p. 168
bioassay, p. 40
California river systems, p. 168
Colorado River Basin, p. 765
Columbia River Basin, p. 765
concentrations, p. 39
farmstead water supplies, p. 776, 124
fresh water, p. 39, 40
Gulf of Mexico Western Basins, p. 765
Pecos River Basin, p. 168
Platte River, p. 168
Red River Basin, p. 765
Rio Grande, p. 765
stock water, p. 777
toxicity synergism, p. 40
Upper Missouri River Basin, p. 765
Diuron
irrigation water, p. 755
DO see Dissolved oxygen
Domestic water
farms, p. 119
farmstead water supplies, p. 119
water quality, p. 119
Dranunculus
nematodes, p. 142
Drinking Water Standards—USPHS, p. 119, 163
methylene blue active substances, p. 25
public water supplies, p. 19, 20, 21, 22, 23
radioisotopes, p. 50
treatment facilities, p. 19
Dursban
toxicity, p. 37
ECHO viruses
water pollution sources, p. 747
Ecosystems
benthic flora, p. 54
220
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Effluents
laboratories, p. 92
marine and estuarine, p. 37
oil refinery, p. 46
titanium, p. 76
Electric power industry
industrial water, p. 188,188
water consumption, p. 788
Endosulfan
toxicity, p. 37, 83
Endothall Na and K salts
irrigation water, p. 159
Endrin
toxicity, p. 37, 83
Enlamoeba coli
irrigation water, p. 161
Enteric cytopathic human orphan viruses
see ECHO viruses
Epilimnion
water temperature, p. 43
ESP see Exchangeable sodium percentage
Estuaries
floating materials, p. 76
pesticides, p. 82
plant nutrients and nuisance organisms, p. 77-80
sediments, p. 76
water pollution sources, p. 67
Estuarine organisms see Marine and estuarine organisms
Euglena
chemical composition, p. 55
European Inland Fisheries Advisory Commission
sediments, p. 47
Eutrophication
nutrients, p. 51
Evapotranspiration
humid areas, p. 173
plant growth, p. 148
saline soils, p. 148
soil water movement, p. 145, 148
Exchangeable sodium percentage soils, p. 164
Eye irritation
swimming, p. 15
Farm ponds
farmstead water sources, p. 121
water quality, p. 122
Farms
domestic water, p. 119
Farmstead water sources
farm ponds, p. 121
ground water, p. 122
precipitation (atmospheric), p. 121
Farmstead water supplies
bacteria, nonpathogenic, p. 123
carbon chloroform extractable substances, p. 124
chlorinated hydrocarbon pesticides, p. 125
chlorination, p. 127
coliforms, p. 125
color, p. 116, 124
copper, p. 123
dairy sanitation requirements, p. 120, 121
dissolved solids, p. 116, 124
domestic water, p. 119
hardness (water), p. 121, 122
hydrogen ion concentration, p. 124
iron, p. 123
manganese, p. 123
microorganisms, p. 116, 125
odor, p. 124
organic pesticides concentration, p. 116, 124
Farmstead water supplies (Cont'd)
psychrophilic bacteria, p. 123
radioisotopes, p. 116, 125
taste, p. 116, 124
trace elements, p. 116, 125,125
turbidity, p. 116, 121
water analysis, p. 126
water pollution sources, p. 122
water quality, p. 113
water quality control, p. 114, 126
water quality criteria, p. 116
water sources, p. 121
water treatment, p. 121, 122,127
Farm wastes
biochemical oxygen demand, p. 132
Fasciola hepatica
irrigation water, p. 162
Fecal coliform monitoring criteria
secondary contact recreation waters, p. 9, 10
surface waters, p. 3, 9, 12
Fecal coliforms
animal wastes, p. 12
Phelps Index, p. 22
primary contact recreation waters, p. 4, 12, 13
public water supplies, p. 20, 21, 22
secondary contact recreation waters, p. 8, 9, 10
see also Coliforms
Fecal streptococci
animal wastes, p. 12
Federal Radiation Council
Radiation Protection Guides, p. 51
Federal Water Pollution Control Act
Water Quality Act of 1965, p. vi, 6
Fenoc
irrigation water, p. 759
Fenthion
toxicity, p. 37
Fiber scouring—textiles
water quality, p. 196
Field crops
salt tolerance, p. 149,150
Filtration
water purification, p. 128
water treatment, p. 18
Fish
bioindicators, p. 115
stock water, p. 131,757
see also Anadromous fish; Catadromous fish; Cold
water fish; Fresh water fish; Warm water fish
Fishing
recreation, p. 8
Fish migration
water temperature, p. 69
Fish reproduction
dissolved oxygen, p. 43
Fish and wildlife see Wildlife
Flavor see Taste
Floating materials
aquatic life, p. 48
estuaries, p. 76
exclusion from streams and lakes, p. 48
sea water, p. 76
spawning, p. 48
Floating plants
navigational threat, p. 53
nuisance growth, p. 52
nutrients, p. 52
Flukes
animal parasites, p. 141,142
221
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Fluorides
industrial wastes, p. 37
phytotoxicity, p. 154
public water supplies, p. 23, 23
toxicity—sea water, p. 88
Foliar absorption
irrigation wate |