Water  Quality  Criteria
               Report of the
     National Technical Advisory Committee
                 to the
           Secretary of the Interior

               APRIL 1, 1968
             WASHINGTON, D.C.

For sale by the Superintendent of Documents, U. S. Government Printing Office
                  Washington, D.C., 20402—Price $3.00

                           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
     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
     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-
     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.

                                Subcommittee  for recreation and
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,
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,

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.
  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,
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,
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,
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.

DR. BENJAMIN H. PRINGLE, Supervisory Chemist,
  Northeast Marine Health Sciences Laboratory,
  Public Health  Service, U.S.  Department  of
  Health, Education, and Welfare, Narragansett,
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,
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,
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,
DR. MAURICE N. LANGLEY, Chief, Division of Ir-
  rigation and Land Use, Bureau of Reclamation,
  U.S. Department of the Interior,  Washington,
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-

   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,
 DR. EVERETT P. PARTRIDGE, Consultant, Beaver,
 MR. SHEPPARD T.  POWELL, Sheppard T.  Powell
   and Associates, Baltimore, Md.
   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.

    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


    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

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

              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
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


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
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

             Section I
recreation and aesthetics

     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
   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.

   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.
of   recommendations
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
       (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
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-
     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

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-
   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-
  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-

Recommended criteria for aesthetic


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-
  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
   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
  (a) Materials that  will  settle to form  objectionable
   (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.

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
  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
  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
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

  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
  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
  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
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
   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
  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
  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
  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.

  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

  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
  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-
  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
  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

  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
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-

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-
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
   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.

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
   In view of  the  foregoing, the Subcommittee
would suggest, as a general practice, application of
selected  bibliography
  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.
  1966. U.S. House of Representatives, 89th Cong., 2nd
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.
  1962.   Outdoor  recreation  for  America.   Superin-
  tendent  of Documents,  U.S.  Government Printing
  Office, Washington, D.C.
  ENGINEERING DIVISION.   1963.  Coliform standards for
  recreational waters.  Amer. Soc. Civil  Engr.,  Proc.
  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.

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

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.
(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-
(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.
    OKUMOTO.  1955.  Compounding  ophthalmic  solu-
    tions. J.  Am. Pharm. Assoc. (Prac. Pharm. Ed.),
    16:  742-746.

       Section II
public water supplies

     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.
   We have listed two types of criteria defined as
   (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-

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
     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.

                  TABLE  ll-l.   Surface  Water Criteria  for Public Water  Supplies

                                                Permissible                       Desirable
            Constituent or characteristic              criteria                          criteria              Paragraph

     Color  (color  units)	75  	<10 	.1
     Odor  	Narrative	Virtually absent	2
     Temperature  *  	do	Narrative  	3
     Turbidity  	do	Virtually absent 	4
     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
         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
         Toxaphene * 	0.005 	do	8
         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.

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

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-
   (3) More than 1 F hourly temperature  varia-
       tion  over that caused  by ambient  condi-
   (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,
   (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
   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-

 Paragraph  5:  Coliform and  Fecal Coliform Or-
   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

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

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
  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.

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
   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
   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-

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
   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-

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-

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
   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.

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.
     WATER AND WASTEWATER.   1967.  12th ed. Amer.
     Public Health Assoc. N.Y.
     WELFARE.   1962.   Public Health Service  drinking
      water standards. PHS Pub. 956.  Washington, D.C.

         Section III
fish, other aquatic life,
        and wildlife

     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,

      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
   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

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
  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.

        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.

       and  key
     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
   (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-

   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

 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
   (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
   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-
 	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
 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

  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

                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 or petrochemicals should not be added in
such quantities to the receiving waters that  they

   (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-
   (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"

   (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

   (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
   (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
   (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-

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
   (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

   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 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.

   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.

   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-

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.

   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"

   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

              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.

  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
  (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.

   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:
    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.

               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
   Aquatic plants of greatest value as food  for
waterfowl thrive best in waters with a summer  pH
range of 7.0 to 9.2.


   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 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-
               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  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.


              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.


              Water quality suitable for fish  and other aquatic
           organisms will be adequate for wildlife.

                                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

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
  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
   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

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
  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  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
  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

   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
  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

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.

 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
     (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
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

  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
   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
   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

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

 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
   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).

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 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
   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

 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
  Length of
exposure (days)
 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
   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
   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
                                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

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

   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.

TABLE 111-3.  Concentration of Phenolic Com-
   pounds That Cause Tainting of Fish Flesh
  After Bandt (1955) page 77 (except for phenol).
     Compound or
 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-
  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:
    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

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
   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
   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

  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

  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
   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

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

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
  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
  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-
   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.

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
  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
   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
   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
  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

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
   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'
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

„ 43.4
... 0.92
_ _ 0.13


1 641

1 793
1 658

1 820
1 687
1 8

1 729
8 1

1 77
1 20
1 080



                                       Hydrodictyon   Microcystis
                                                                             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

._ 35.27
__ 1,040
- 2,300

0 34

4 21
0 38
1 373
1 963

0 79

40 23
0 06
5 230
3 866

0 34
0 28
2 388
2 180

0 68
0 19

    1 Lawrence (personal communication).

   (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
   (6) An increase in organic materials and nu-
       trients, especially  phosphorus,  in  bottom

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
    (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
   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

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
   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


   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.
   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-

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-
   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

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
    (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-
  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

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
Ca-Mg concentra-
tion—170 mg/l as
CaCOs Navicula
   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
   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

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
    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-
  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.

                                    TABLE  III-5A. Pesticides *
         [48-hour TLm values from static bioassay, in micrograms per liter. Exceptions are  noted.]
Aldrin 5
Baveon 5
Baytex 5 _
Benzene hexachloride
Bidrin _
Carbaryl (sevin)
Chlordane 5 _ _ _
ODD (IDE) 8 - _
DDT5 . _ _ -
Delnav (dioxathion) _.
Delmeton (systex) 	
Diazinon ^
Dibrom (naled)
Dieldrin 5
Dilan _ _
Dichlorvos5 (DDVP) ..
Stream invertebrate 1
Species TLm
Pteronarcys _
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 "
Ethyl guthion E
Guthion 5
Heptachlor 6
Kelthane (dicofel)
Kepone _ _
Malathion 5
Methoxychlor B
Methyl parathion 5
Parathion 5
Phosdrin 5

Tetradifon (tedion) __.
Toxaphene 5

-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





Cladocerans -
Species TLm

D pulex

D. magna 	
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

4 5



Fish 3
Brook trout-
Brown t.' 	
Rainbow t 	
Brown t. 	
Rainbow t 	

Rainbow t

Brook t. 	
Rainbow t 	
Bluegill .
Rainbow t.
Rainbow t.

Rainbow t 	
Brook t.
Rainbow t 	
Bluegill _ _
Rainbow t.
Rainbow t 	
Bluegill -
Rainbow t 	
Bluegill _
Rainbow t 	
do .
do _ _








  * See notes following Table Ill-SB.


   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
    (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-
            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

                                       TABLE  Ill-SB.  Pesticides,  cont.

                              HERBICIDES,  FUNGICIDES,  DEFOLIANTS,  ALGICIDES
Azide, potassium
Azide sodium
Copper chloride
Copper sulfate
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
DEF - 	
Dexon _ _ __ ._
Dyrene _ ._ __ „
Endothal, copper
Fenac, acid
Fenac, sodium
Hydram (molinate) ___
Hydrothol 191 	
Lanstan (korax)
Silvex, PGBEE
Silvex, isoctyl
Silvex, BEE .__
Simazine _
Sodium arsenite 	
Tordon (picloram) 	
Vernam :' (vernolate)

Stream invertebrate 1
Species TLm

Pteronarcys 44 000
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


D. pulex _

D. magna 	
D. pulex

D. magna

D. pulex

D. magna

D. pulex

D pulex

D pulex

D pulex









Fish "
Rainbow t.

Rainbow t.
Rainbow t 	
Rainbow t 	
Bluegill __
Rainbow t 	
Channel Cat-
Rainbow t 	

Rainbow t 	
do _ . _
Very low
Rainbow t
Rainbow t.
do _ _




Low toxicity.



  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 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
                     Concentration (mg/l)
Trout	  	  5.0
Bluegills 	  4.2
Fathead minnows	  2.3
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
Lirceus fontmalis	 10.0
 Crangonyx setodactylus1

 Stenonema  ares  	
 Stenonema  heterotarsale	
 Isonychia bicolor  	
 Hydropsychidae (mostly
 Orconectes rusticus __-

 Goniobasis livescens _.



 Chlorella  	   3.6
 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  	
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,
   	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.
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.
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.
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.
	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.

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

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.
and   estuarine
  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.

     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
   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.
   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

 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
   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
   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 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-

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
  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
  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

  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-
    (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-
    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
   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
   (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-

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
  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.

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
   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-
  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
  The survival of toadfish embryos was indirectly
proportional to  the  concentration of  oil in water.

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

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"
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.


   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

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.

   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-

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
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

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
              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,
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-

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
  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
  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

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
  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

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

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-
    (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
   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
   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
   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

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
   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
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

  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
  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

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.
    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.

  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
  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

 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-

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
  (4)  The time  elapsed  between feeding and
  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 >
   (2)  Order of stability products of the sulfides:
   (3)  Order of stability of chelates:  Hg>Cu>
       Ni >Pb>Co>Zn>Cd >Fe>Mn >Mg>
   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
   Metal-organic compounds  may  be either  more
toxic than the metal ion (ethyl mercuric chloride)
or much less so  (cupric ion  and copper salicyl-
   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.

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
   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

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
  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

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

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
     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

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

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
   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.

   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
   Laboratory administrators should be responsible
for  the  periodical examination  of the  toxicity  of
the effluent discharged into natural waters by  their

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
  (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
     (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:

             \ 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.

       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-

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.
  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.
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.
   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,

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,
  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
  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
  The germination of seeds and the growth of

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,
  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
  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,
  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
   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

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.
   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
   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
  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)

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.
   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-
  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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  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-
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
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-
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-
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
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.

  photosynthesis fails to occur because of ineffective light
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
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
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
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).
  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
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-
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
MOTILE—Exhibiting or capable of  spontaneous move-
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.

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
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
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
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
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-

  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
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.

    Section IV
agricultural uses

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-
  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

 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
   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
   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
   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

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.
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.

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
   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
   The following summary of criteria should  be
used in conjunction with references to the text of
the report as noted.



   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-


   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-

                   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
Dissolved organic  compounds	No recommendations for  total   	   124
                                The concentration of persistent
                                   chlorinated organic pesticides
                                   should not exceed the follow-
                                        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
                                       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
Radionuclides  	Strontium-90 	   10  .   	   125
                                Radium-226  	    3   	   125
                                In absence  of  above  radionu-
                                   clides,  1,000   pc/l  gross  ft
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.


TABLE IV-2.  Key Water  Quality  Criteria  for
                 Livestock Use
Total dissolved solids (TDS)
Hazardous trace elements:
Organic substances:
    Algae  (water bloom).
    Parasites and
    Dissolved organic
.< 10,000 mg/l, depend-
   ing upon animal  spe-
   cies and  ionic  com-
   position of the water.

_<0.01 mg/l
_<0.05 mg/l
_<0.01 mg/l

.Avoid abnormally heavy
   growth of blue-green
 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-

  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
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.
   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.

   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

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-

   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).

  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)


  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
                          Crop injury threshold in
                           irrigation water mg/l
Aromatic solvents	
Copper sulfate

Endothall  Na and K



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-
Apparently,  above concentra-
  tions used for weed control.
Beets (rutabaga)->3.5,  corn-
Beets->7.0, corn-<0.35.
Beans-5.0, corn-125.0.
Corn-25,   field  beans-<1.0,
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-
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

  NOTE.—Where the symbol ">" is used, the concentrations in
water cause  no injury. Data are for furrow irrigation unless
otherwise specified.

                                  Scope of  taskforce considerations
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
  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

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-
   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
   1.  Sufficient quantity.—Enough water must be

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
   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
   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-

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
   (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

 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-

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
   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

   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.

   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.

   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

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

tion H.g/1

H. expoxide

tion i(g/l


  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
  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).
limit mg/l
Arsenic 	 0.05
Barium 	 1.00
Cadmium  	0.01
  (hexavalent) .. 0.05
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
Iron _

limit mg/l

Zinc . - _„
Fluoride - -_

limit mg/l
-- 0.7-1.2


  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

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-
   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
     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.

   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

   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
   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-
   (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

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

  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-

  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;
   (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

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).
water  supplies

              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,

   TABLE IV-8.  Normal Water Consumption
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

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
Fish  as  indicators  of  water  safety  for
   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)
                mg/1 for fish
Toxic effects on animals
Aldrin	0.02  	3 mg/kg food (poul-
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
Endrin  	0.003 (bass)_._3.5 mg/kg body
                              weight in  food
  fermate	1.0 to 4.0	
  chlor  	0.2 (bass)	14 mg/kg alfalfa hay,
                              not toxic  (cattle).
Parathion  	2.0 (goldfish)__75 mg/kg body weight
                              in food (cattle).
  phenol	0.35 (bluegill)__60 mg/1 drinking water
                              not toxic  (cattle).
  (allethrin) __2.0 to 10.0	1,400 to 2,800 mg/kg
                              body weight in food
Silvex	5.0 	500 to 2,000  mg/kg
                              body weight in food
Toxaphene ___0.1 (bass)	35 to 110 mg/kg body
                              weight in  food (cat-
  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

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
   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-
  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.

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
   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


   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).

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

  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
Dairy cattle
Beef cattle
Sheep (adult, dry)

Threshold salinity
concentration 1
TDS mg/1
. ._ 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

TABLE 1V-11.  Suggested Maximum Allowable
  Concentrations of Certain Inorganic Elements
        in Farm Animals' Water Supply
                               Suggested maximum
                               concentration, mg/l
 Chromium (hexavalent)
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)
Toxic dose of As,
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

   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

   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

   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

   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

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

  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

  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

  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.

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

  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
  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
  Pesticides and herbicides, along with other com-
pounds  which have dangerous properties when out

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
  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

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
  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
  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

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-

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
   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
    TABLE IV-13. Ether-Resistant Viruses
     Coxsackie viruses—
         Group A.
         Group B.
Enteric cytopathic human orphan (ECHO) viruses.
Picornaviruses of lower animals.
Foot and  mouth virus (not present  in United States).
Teschen's disease of swine (not present  in  United
African horse  sickness  (not  present  in the  United
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
  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-
  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

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
   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.

  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.
water  supplies

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.

   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

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
   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.

   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.

   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

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
   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-
                    water  quality
                    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.

   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
   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
   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

give a usable parameter which  represents a soil
salinity value which can be correlated with plant
   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
                             ' 25% i
                           10%   50%  YIELD REDUCTION
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-

 FIGURE IV-2. Salt tolerance of field crops'
Soybean  . .
Rice (Paddy)
Flax  .
                       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-
                           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
Birdsfoot trefoil
Beardless wildrye
Meadow foxtail  .   .
Clovers,  alsike & red
                     ECe IN MILLIMHOS PER  CM  AT  25 C
                     12     14     16     18     20     22
                            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-

  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
ECeXl03 =
EC. X10" = 10
Bell pepper
Sweet corn
Potatoes (White
EC.xl03 = 4
Green beans
EC.xl03 =
                  FIELD  CROPS
ECeXl03 = 16
Barley (grain)
Sugar  beet
ECeXl03 =
ECeXl03 = 10
Rye (grain)
Wheat (grain)
Oats (grain)
Sorghum (gram)
Corn (field)
ECeXl03 = 6
ECeXl03 = 4
Field beans
   FORAGE CROPS (in  decreasing order tolerance)
 ECeXl03 = 18
 Alkali sacaton


 Nuttall  alkali-
 Bermuda grass
 Rhodes grass
 Rescue grass
 Canada wildrye
 Western wheat-
 Barley (hay)

 Bridsfoot trefoil
 ECeXl03 =

 ECe X 10s = 12
 White sweet-
 Yellow sweet-
 Perennial rye-
 Mountain brome
 Strawberry clover
 Dallis  grass
 Sudan grass
 Hubam clover

 Alfalfa  (California
 Tall  fescue
 Rye (hay)
 Wheat (hay)
 Oats (hay)
 Blue grama
 Meadow fescue
 Reed canary
 Big  trefoil
 Smooth brome
 Tall  meadow
 Cicer milkvetch
 Sickle milkvetch
 ECeXl03 = 4
 White Dutch
 Meadow fox-
 Alsike clover

 Red clover
 Lad i no  clover
 ECeXl03 =
High salt tolerance
Medium salt tolerance
Low salt tolerance
Date palm


                                                      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
in yield per unit  change  in  ECe,
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-

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

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
  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
                    For water used
                  continuously on all
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.

   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

   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.]
Athel (Tamarix
Palm (Phoenix
Date palm (P.
dactyl ifera)
Sugar beet
Garden beet

Acala cotton
Pima cotton
Field pea
Ragged Robin
Bell pepper
Sweet potato
Lima bean


Black walnut
Persian (Eng-
lish) walnut
Jerusalem arti-
Navy bean
American elm
Grape (Sulta-
nina and
Kadota fig

'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

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-
   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//.
	.        —ex-
 . /Ca" + Mg"
V     2

  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)
                   Rootstock or variety
   Limit of
 tolerance to
chloride in soil
solution me/I
Citrus	Rangpur  lime, Cleopatra	   50
             Rough  lemon, tangelo, sour_   30
             Sweet orange, citrange	   20
Stone fruit	Marianna  	   50
             Lovell,  Shalil  	   20
             Yunnan 	   14
Avocado  	West Indian  	   16
             Mexican  	   10

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

  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

  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









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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
  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-

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
  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.

   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
   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.

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

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
  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

                                                                               - 15
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)

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
  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.

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-
Environmental  factors


   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

  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

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

   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
                       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
  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 ..






+ 1,500

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,
Ca-Mg, S-C; Na-P, S-C 	
Ca-Mg, S-C; Ca-Mg, C-b; Na-P,
Ca-Mg, C-b; Ca-Mg, S-C 	
Ca-Mg, S-C; Na-P, C-b; Na-P,



+ 15,000
+ 15,000


+ 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

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;
   (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

  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 =
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

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
   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
   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-
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

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


  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
  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,

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.

   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-

 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.

   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-

                 ration extract after irrigation is
       ECe(i) = electrical conductivity  of the soil
                 saturation extract before  irriga-
        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
1,920 . ..

. _ 1


1 2


2 3

  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,

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
               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
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
  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

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
   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


   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
   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
   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
   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.

                                                     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,
                                                  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
  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

are discussed in the A.O.A.C. 80th annual meeting
  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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Section V

      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
   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

        and  key   criteria
    TABLE  V-l.  Task Forces and  Their
IV ..
V _-
VI ..
.Steam generation and cool-

.Textile, lumber, paper, and
   allied products.
.Chemicals and allied prod-
.Petroleum and coal products.
-Primary metal industries
. Food and  kindred products,
   and leather tanning and
 All SIC  codes
   and electric
 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
  (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-

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)








Boiler feed
Cooling and sanitary
Industrial group condensing service, etc.
Food and kindred
Textile mill products
Lumber and wood
Paper and allied
Chemicals and allied
Petroleum and coal
Leather and leather
Primary metal in-
Other industries.-
Total industry 	
Thermal electric
Total . _

















959 a




























water use,


























   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.




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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
  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
steam  generation
            and   cooling

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
   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
  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

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
                              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
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
                                                                 Once through
                                                                                     Makeup for recycling
  Low and
  medium  High pressure
  pressure   700 to 1,500  High pressure
0 to 700 psig    psig     > 1,500 psig
                                                                        Brackish '
   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
   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)
   Methylene  blue active	       1          2         10         1.3         (2)        1.3         1.3
   Carbon tetrachloride	     100        100        100         (4)         (')       100        100
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).

    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 - --

Total _ -



  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
Recirculation 	  16,533

   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.
            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
            Suspended solids and colloids
                Straining 	   X      X
                Sedimentation  	   X      X
                Coagulation  	  —      X
                Filtration 	  —      X
                Aeration  	  —      X

            Dissolved solids  modification
                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




                                                       NOTES.— "—" Not used.
                                                                              "X"—May be used.

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
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
Alkalinity (CaCCs)
pH, units
Color, units
Methylene blue active--
Carbon tetrachloride ___
Chemical oxygen demand
Dissolved oxygen (O2) 	
Temperature, F
Suspended solids

0 to 150
150 to 700
8.2 10.0

700 to 1,500
8 2 9.0
1,500 to
5,000 psig
Once through Makeup for recirculation
Brackish 1
Brackish *
   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-
   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).

                        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
  With time,  the new synthetic fiber plants were
located near the  natural  fiber plants. (The  syn-
thetic fiber production is part of the chemical
  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

Processes  utilizing water

  The  sizing  or  stiffening of the warp fibers by


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
Iron (Fe)
Coooer (Cu)




pH, units
Color, units _ _




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.]
                          Scouring Bleaching  Dyeing
  1 Accepted as received (if meeting total solids or other limit-
ing  values); has  never been a problem  at concentrations
  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
   solids 	       5555
   (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).

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
  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.


          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

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)
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).

         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
   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
                  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.
"b ",
s :

                            BROWN STOCK
                             WASHING AND
                                         Additional water required
                                            for  bleaching pulp
Figure V-l—Pulp and paper  industry:  water intake, recycle, and discharge.
                             gallons of water per ton of product.)
                                                                             (All data given as

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.)
            Chemical pulp and paper

      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
  1 Accepted as received (if meeting total solids or other limit-
ing  values);  has  never been a problem  at concentrations

  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
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

10 2
                                     1 Accepted  as  received (if meeting  total solids or  other
                                   limiting values); has never been a problem at  concentrations
                                     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

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.

                                               Significant indicators of water  quality
            Part III.
   and  allied
            (SIC 2
                        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
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.
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) 	
Suspended solids 	
5-day BOD (O2)
COD (02)
Dissolved oxygen (O2)_
Alkalinity (CaC03) 	
SIC 2815
Interm. coal
tar products
                                 1 Potable water.
                                 2 Accepted as  received (if meeting total solids

    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

Industry group and industry
Alkalies and chlorine 	
Intermediate coal tar
Organic chemicals, n.e.c.1—
Inorganic chemicals, n.e.c.1
Plastic materials and
Synthetic rubber
Pharmaceutical prepara-
tions _
Soaps and other deter-
gents _ _ _
Paints and allied
Gum and wood
Nonlisted industries 2

Chemicals and allied
   products 	 564
      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
Silica (SiO2) ...
Iron (Fe)
Calcium (Ca) 	
Ammonia (NHs)
Sulfate (SO4)
Chloride (Cl) 	



(CaC03) _„.
pH units
BOD (02)
COD (02)
Temperature ._
DO (O2)


  1 Accepted  as  received (if meeting total solids or other
limiting values); has never been  a  problem at concentrations

  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.]

SIC 2818

SIC 2819

SIC 2821




SIC 2822



SIC 2834
drugs and
tical prep-
arations *



SIC 2841
soap and




SIC 2851

SIC 2861
paints and gums and
allied wood






SIC 2871




SIC 2892



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.

                                                      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-
  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

   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
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
   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
Silica (SiO2) 	
Iron (Fe)
Calcium (Ca) __
(Mg) .
Total sodium and
(Na, K)
Sulfate (SOO



Chloride (Cl)___
Fluoride (F)
Nitrate (N03) ..
solids .
solids _ _
Color, units
pH, units



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.]
Silica (Si02) 	
Iron (Fe)
Calcium (Ca) .
Total sodium and
(Na, K)
Sulfate (SO,)—-
Chloride (Cl)- .
Fluoride (F) 	
Nitrate (N03) _.
Color, units 	
pH, units


                                                      1 Accepted as  received  (if  meeting total  solids or other
                                                     limiting values); has never been a  problem at concentrations
                                                      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).

                                               Description  of industry
           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
                                                                                 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
                                               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
                                                 Most of  the iron and steel making facilities in

 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
   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 _.
Boiler feed, etc..
   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
   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-

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
   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
solids _ -

pH, units
Chloride (Cl)_
Temperature, F_
Organics, carbon


   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
   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

   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.]
Settleable solids
Suspended solids
Dissolved solids
Alkalinity (CaCOa)
Hardness (CaCO3)
pH, units _ _ _
Chloride (Cl)
Dissolved oxygen (Oz)
Temperature, F
Floating material

hot rolling,
gas cleaning

Selected rinse waters
Cold rolling
  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).

                                               food  canning  industry
                                               (SIC's  2032  and   2033)
                                                  iption of industry
               Part  VI.
and  kindred
        and  leat
 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

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
  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
  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.

Water quantity
- - 48

Percent of
intake quantity

                               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:

In-plant use Water quantity
Raw product washing .
Product transport *
Product preparation 2
Incorporation in product3-—
Steam and water sterilization
of containers
Container cooling
Plant cleanup

of total use
  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.]
Alkalinity (CaCO3)
pH, units
Calcium (Ca) 	
Chlorides (Cl) ___
Sulfates (SO4) __-
Iron (Fe)
Manganese (Mn)_
Silica (Si02),
Nitrate (N0rt) 	
Nitrite (N02) 	
Fluoride (F)
Organics: Carbon
Chemical oxygen
demand (O2) 	
Odor, threshold
Taste, threshold
Color, units .
Dissolved solids 	
Suspended solids.
count/100 mi-
1 As specified by NTA Subcommittee on Water
Criteria for Public Water Supplies, in this volume.
ce ncen-
  2 Accepted as received  (if  meeting  total  solids  or  other
limiting values); has never been a problem at concentrations
  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)
                     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).

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

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
   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
  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
   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.]
Alkalinity (CaC03)
pH, units
Chlorides (Cl) 	
Sulfates (SO4)--
Iron (Fe)
Manganese (Mn)


500 2
500 2

Fluoride (F) _
Total dissolved
Organics, CCE
Coliform bacteria-
Color, units
Taste . _


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
  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).

                                                   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,
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.]
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 _ _ _



6 0-8.0
(3, 4)
(3, 4)

  1 Accepted  as  received  (if  meeting  total solids  or other
limiting values); has never been a problem at concentrations
  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).

                  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
Acidity (CaCO3)
Chemical oxygen
Coliform bac-
teria (count/
100 ml) 	
Color, units 	

Iron (Fe)
pH, units
Silica (SiO2)—
solids _ _
Sulfate (SOO--
Chloride (Cl) ._

  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

  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
                                                   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.]
Chemical oxygen
Coliform bac-
teria, (count/
100 ml) 	
Color, units

Iron (Fe) 	
pH, units
Silica (SiO2) „
Sulfate (SO,)-_
Chloride (Cl) _.
  iZero, not detectable by test.
  3 Accepted  as  received (if meeting total solids or  other
 limiting values); has never been a problem at concentrations

  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).

     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.
     MISSION.  1967.  ORSANCO Stream-Quality Cri-
     tena  anc*  Minimum  Conditions.  Ohio River
     Valley Water  Sanitation  Commission,  Cincinnati,
(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
     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.
     WELFARE.  1962.  Public Health Service Drinking
     Water Standards.   Public Health Service Publi-
     cation 956.   U.S. Government  Printing Office
     Washington, D.C. 20402.
     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.


                            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
   alkalinity—pH recommendation, p. 40
   irrigation water, p. 155
   irrigation water, p. 158
Activated carbon
   water purification, p. 129
   oil, p. 72
   soil chemical properties, p. 173
   see also Sodium adsorption ratio
   supplemental irrigation, p. 175
   water purification, p. 128, 129
   water treatment, p. 128, 129
   national goal, p. 5
   surface waters, p. 3
   water quality, p. 3
   water quality recommendations, p. 5, 6
   toxicity, p. 37, 83
   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
   fresh water recommendation, p. 63
   median tolerance limit, p. 64
Alkaline soils
   humid areas, p.  174
   supplemental irrigation, p. 174
   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
   phytotoxicity, p. 152
   irrigation water, p. 158
   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

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
  irrigation water, p. 161, 162
  prevention, p. 38
  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
  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
   zones of passage, p. 31
Benthic flora
  ecosystem indicator, p. 54
  nutrients, p. 54
  phytotoxicity, p. 153
  toxicity, p. 37, 83
  alkalinity—waterfowl habitat, p. 94
  phytotoxicity, p. 156
  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
  application factor, p. 37
  fish, p. 115
  stock water, p. 115, 131,131
Biological magnification
  water pollution, p. 81
Biological terms see Glossary
  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
  phytotoxicity, p.  153, 153
  public water supplies,  p. 23
  toxicity, p. 37
  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

   phytotoxicity, p. 153
   toxicity—fresh water, p. 61
   toxicity—sea water, p. 86

Calcium carbonate
  cause of acidity, p. 41
  hardness (water), p. 41
California river systems
  dissolved solids, p. 168
  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
  pesticide residues, p. 81
Catadromous fish
  spawning migration, p. 31
  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
  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
  toxicity, p. 37, 83
  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
  canneries, p. 210, 211
  farmstead water supplies, p. 127
  water purification, p. 127, 128
  water treatment, p. 18, 127, 128, 129
  ammonia reaction, p. 22
  psychrophilic bacteria, p. 123
  phytotoxicity, p. 153
  toxicity of hexavalent-fresh water, p. 61
  toxicity—sea water, p. 86
  chemical composition, p. 55
  irrigation efficiency, p. 145
Clostridia, p. 140
Coal, p. 205
  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
  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
  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

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
  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
  toxicity, p. 37
Crop injury levels of herbicides
  irrigation water, p. 118
  irrigation effects, p. 144
  salt tolerance, p. 148, 150
Crude oil see Oil
  pesticides, p. 82
  aquatic life, p. 35
  marine and estuarine organisms, p. 35, 68
Currituck Sound, N.C.
  silts, p. 96
  fresh water bioassay, p. 65
  toxicity—fresh water, p. 65
  toxicity—sea water, p. 88
  livestock poisoning,  p. 137
  Nematodes, p. 142

  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
  irrigation water, p. 755
Daphnia magna
  pH, p. 41,61,62,  64
Daphnia pulex, 61, 62, 64
  irrigation water, p. 156
   residues and wildlife, p. 97
  toxicity, p. 37, 83
Deep wells
   irrigation wells, p. 113
Definitions see Glossary
   fresh water recommendation, p. 63
   median tolerance limit, p. 64
Degradables see Alkylbenzene
   sulfonates; Linear alkylate sulfonates
  boiler feed water, p. 193
   cooling water, p. 193
   water treatment, p. 206
  permissible levels, p. 37
  toxicity, p. 65, 88
  irrigation water, p. 759
  toxicity, p. 37, 83
  irrigation water, p. 759
  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
  irrigation water, p. 755
DO see Dissolved oxygen
Domestic water
  farms, p. 119
  farmstead water supplies, p. 119
  water quality, p. 119
  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
   toxicity, p. 37

ECHO viruses
  water pollution sources, p. 747
  benthic flora, p. 54

  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
  toxicity, p. 37, 83
Endothall Na and K salts
  irrigation water, p. 159
  toxicity, p. 37, 83
Enlamoeba coli
  irrigation water, p. 161
Enteric cytopathic human orphan viruses
  see ECHO viruses
  water temperature, p. 43
ESP see Exchangeable sodium percentage
  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
  chemical composition, p. 55
European Inland Fisheries Advisory Commission
  sediments, p. 47
  nutrients, p. 51
  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
  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
  irrigation water, p. 759
  toxicity, p. 37
Fiber scouring—textiles
  water quality,  p. 196
Field crops
  salt tolerance, p. 149,150
  water purification, p. 128
  water treatment, p. 18
  bioindicators, p. 115
  stock water, p. 131,757
  see  also Anadromous  fish; Catadromous  fish; Cold
     water fish; Fresh water fish; Warm water fish
  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
  animal parasites, p. 141,142

  industrial wastes, p. 37
  phytotoxicity, p. 154
  public water supplies, p. 23, 23
  toxicity—sea water, p. 88
Foliar absorption
  irrigation wate