UNITED STATES
        WASHINGTON, D.C. 20460

                          by the

            Office of Air and Water Programs
Division  of Water Quality and Non-Point Source  Control

                         and the

           Office of Research and Development
        National Eutrophication Research Program
                 Washington,  D.C. 20460
   For sale by the Superintendent of Documents, U.S. Government Printing Office. Washington, D.C. 20402 - Price $2.86


    The limited number of publicly owned high
quality freshwater lakes in the United States
combined with a growing population has resulted in
a pressing need for sound management programs
designed to protect and enhance the quality of the
Nation's lakes.

    The Federal Water Pollution Control Act
Amendments of 1972 require the Administrator of
the Environmental Protection Agency to issue
information on methods, procedures and processes
as may be appropriate to restore and enhance the
quality of the Nation's publicly owned freshwater
lakes [Subsection 304(i), PL 92-500],  This report
is prepared pursuant to that legislative mandate.
                              Robert W.  Fri
                          Acting Administrator
                    Environmental Protection Agency

                    LIST OF PARTICIPANTS


              Office of Air and Water Programs

   Division of Water Quality and Non-Point Source Control

Mr. W. L. Kinney, Subcommittee Chairman

llr. J. I. Lewis, Alternate Subcommittee Chairman

Dr. L. J. Guarraia

Mr. J. P. Gating

Mr. D. K. Boynton, Jr.

             Office of Research and Development

             Division of Processes and Effects

Dr. F. G. Wilkes

                Office of Radiation Programs

              Criteria and Standards Division

Mr. R. S. Dyer


          National Eutrophication Research Program

Mr. T. E. Maloney                 Dr. S. A. Peterson

Dr. K. W. Malueg                  Dr. W. D. Sanville

Mr. D. W. Shults                  Dr. F. S. Stay, Jr.

Dr. C. F. Powers

              Office of Air and Water Programs
Mr. K. M. Mackenthun
Mr. B. W. Everling
             Office of Research and Development
Dr. D. Yount
Mr. D. Ehreth
       Office of Hazardous Materials Control Programs
Mr. V. Grey
Mr. E. Brooks
         Office of Enforcement and General Counsel

Mr. A. W. Eckert

                Office of Federal Activities

Mr. P. Smith

             Office of Planning and Management

Mr. J. Jacknow

              Office of International Affairs

Mr. J. Tarran


Dr. D. Duttweiler
Southeast Environmental Research Laboratory
Athens, Georgia

Dr. L. P. Seyb
Pacific Northwest Environmental Research Laboratory
Co rvallis, Oregon

Mr. F. H. Rainwater
National Thermal Research Program
Corvallis, Oregon

Mr. R. M. Brice
Shagawa Lake Research Project
Ely, Minnesota

Mr. H. J. Fisher (ret.)
Region V
Chicago, Illinois

    The technical and editorial assistance of Mrs. Marian
Musser is gratefully acknowledged.

Section                                                   Paae

         List of Participants

   I     SUMMARY


 III     LAKE ENVIRONMENTS                                 14
           LAKE TYPES                                      15
           NUTRIENT CYCLING                                23

         OWNED LAKES                                       34
             Point Source Nutrient Removal and Control     38
             Nutrient Diversion                            46
             Control of Allocthonous Sediments             58
             Dredging                                      61
             Nutrient Inactivation                         71
             Dilution and Displacement                     81
             Covering of Sediments'                         84
             Artificial Destratification and Hypolimnetic
               Aeration                                    86
             Harvesting Nuisance Organisms                112
             Biological Control of Nuisance Organisms     124
             Chemical Control of Nuisance Organisms130
           CONSIDERATIONS                   -              150

   V     REFERENCES                                       152
                               VI l

VI     APPENDIX                                         171
         LAKE PROBLEMS                                  171
             Industrial Wastes                          172
             Municipal Wastes                           177
             Agricultural Wastes                        178
             Miscellaneous Sources                      179
               Mine Drainage                            179
               Oil and Hazardous Materials              180
               Watercraft Wastes181
             Eutrophication                             182
               Natural and Accelerated
                  (Cultural) Eutrophication              184
               Consequences of Eurrophication          184
               Effects of Sediments                     188
               Sources of Sediments                     194
             Thermal Pollution197
               Effects of Thermal Pollution             198
               Sources of Thermal Pollution             203
             Selected Toxic Substances203
               Pesticides                               204
               Mercury"                                  211
               Polychlorinated Biphenyls  (PCB's)        219
               Phthalate Esters                         221
               Ammonia'  and Sulfides                     225
             Miscellaneous Problems                     227
               Non-toxic Salts                          227
               Radioactive Wastes                       230

                       List of Tables

Table                                            Page

  1      Comparison of Nitrogen Removal
         Processes                                41

  2      Treatment Plant, Operating and
         Maintenance Costs for Phosphorus
         Removal                                  42

  3      Physical Characteristics of the
         Madison Lakes                            53

  4      Summary of Manpower, Basic Equipment
         and Costs for Alum Treatment of
         Horseshoe Lake, Wisconsin                77
  5      Initial Costs Per Unit Volume
         (Purchase and Installation)               95

  6      Operating Costs Per Unit Volume
         and Time (Energy and Maintenance)         95

  7      Morphological Characteristics of
         Bullock Pen, Boltz and Falmouth Lakes    104

  8      Estimated Fixed/Variable Costs of
         Distributing Sand in an Area South of
         Wyandotte                               142

  9      Estimate of the Cost Involved in the
         Application of 7.6 cm of Sand to
         0.8, 10.1 and 20.2 Hectares  of
         Sediment Contaminated with Mercury      143

   I     Estimated Volume of Industrial
         Wastes before Treatment,  1964            174

  II     U.S.  Electric Power - Past Use,
         Future Estimates                        175

 III     Use of Cooling Water by U.S.
         Industry                                176

  IV     Number of Reported Oil Spills
         in U.S. Waters (over 100  barrels)        180

   V     Annual Loss of Retaining  Volume
         for 148 Lakes                           189

  VI     Effect of Inert Suspended Solids
         on Freshwater Fish                      190

 VII     Effect of Turbidity on Fish
         Reproduction                            191

VIII     Summary of Total Mercury Measured
         in Water Samples from Rivers and
         Lakes Obtained During Oct. and
         Nov., 1970                              216

 IX      State Fishing Restrictions Because
         of Mercury—Sept. 1, 1970               217

  X      Mercury Residues in Fish - 1969
         and 1970                                218

                      List of Figures

Figure                                           Page
  1      Eutrophication:   The Process of
         Lake Aging by Natural Succession         18
  2      Diagrarmatic Sketch Showing Thermal
         Characteristics  of Temperate Lakes        22
  3      Phosphorus Cycle                         25
  4      Sulfur Cycle                             27
  5      Nitrogen Cycle                           29
  6      Carbon Cycle                             33

                         Section I


    The increasing rate of deterioration of the Nation's

public waters has resulted in passage of the Federal Water

Pollution Control Act Amendments of 1972, PL 92-500.

Included within this legislation is the requirement that the

Administrator of the United States Environmental Protection

Agency issue such information on methods, processes and

procedures as may be appropriate to restore and enhance the

quality of the Nation's publicly owned lakes [subsection

304(i) ].  This report is prepared pursuant to that

legislative mandate.  It contains state-of-the-art

information only and the methods have not been subjected to

cos t an a lys es.

    Lakes vary tremendously in their chemical, physical and

biological characteristics depending upon their mode of

origin, their location, the characteristics of their

watersheds and their uses.  Consequently, lake problems also

vary, and most must be dealt with on a case-by-case basis.

    Contaminants may impact upon lake environments in

various ways depending upon the nature of the substance.

Nutrient rich plant growth stimulators such as domestic

sewage and commercial fertilizers cause accelerated

eutrophication:  sedimentation may add to the eutrophication

problems or create unique problems in the absence or

eutrophication:  toxic substances nay poison water supplies,

interfere with normal biological activity or render

commercial and sports fish and crustaceous species unfit for

consumption.  Heated water released to lakes may alter tne

natural thermal structure and upset the composition or" laKe


    Lake restoration measures are not well developed, with

much of the technology still in experimental stages in

laboratories or in small pilot lakes.  Certain tecnniques

have met with varying degrees of success on indiviaual

lakes, but their applicability to ether lakes is unknown.

At this point in time it is impossible to recommend remedial

measures which will prove effective for all lakes or even

particular classes of lakes.  It is the responsibility of

lake managers to define the problems and to implement

rehabilitation or enhancement programs which are best fitted

to the requirements of particular lakes on a case-by-case


    The approach to the rehabilitation of degraded lakes is

twofold:  (1) restricting the input of undesirable materials

and  (2) providing in-lake treatment for the removal or

inactivation of undesirable materials.  Reducino or

eliminating the sources of waste loading is the only

restorative measure needed to achieve the desired level of

improvement in certain lakes in which natural flushing

results in substantial improvements in quality.  However, in

many lakes, particularly those with slow flushing rates, in-

lake treatment schemes may also be required before

significant improvements will be realized.

    Remedial measures which restrict the input of

contaminants include advanced wastewater treatment, nutrient

diversion and allochthonous sediment control.

    Advanced wastewater treatment (AWT)  probably represents

the best method currently available for curbing nitrogen and

phosphorus input to waterways at moderate costs.  Phosphorus

removal efficiency of 80-95 percent can be achieved by

chemical precipitation with alum, lime or ferric salts.

Removal of ammonia and other nitrogen species can be

accomplished by ion exchange, ammonia stripping, breakpoint

chlorination or bacterial denitrification.  Although to date

there has not been documentation evaluating AWT as a means

of restoring a lake, preliminary results both in this

country and in Europe have been encouraging.

    Nutrient diversion offers a possible restoration

technique in situations where the incoming nutrient loaa is

entering from point sources.  This technique has been used

successfully in Lake Washington and has resulted in some

improvement in the Madison Lakes.  Preliminary stuaies on

several lakes indicate that the effects of diversion may not

be readily apparent in small, shallow, highly eutropaic

lakes, due to the remobilization of nutrients from the

sediment pool and the continued influx of nutrients from

non-point sources.

    The useful existence of a lake or reservoir can

sometimes be prolonged by implementing control measures to

reduce the rate of sedimentation.  Prudential land use

management practices within the watershed which minimize

erosion associated with construction, farming, road building

and forestry activities tend to reduce the volume of

sediment input to lakes.  Filter dams and desilting basins

are effective sediment traps under certain conditions.

Sediment control measures not only reduce the rate at whxcn

a lake basin is filled, but also restrict the input of

nutrients adsorbed to sediment particles.

    In-lake treatment, measures which have been usea in  lake

restoration programs or which are now being investigated

include dredging, nutrient inactivation, dilution ana

displacement, covering of sediments, artificial

destratification and hypolimnetic aeration and drawuown.

    Lake dredging not only removes sediment buildup, but

also serves to remove a potential nutrient source.  Little

information is available on the chemical and bioloyioal

effects of dredging, but projects are now under way waicn

will evaluate the total environmental effects.  Tne

relatively high costs of dredging make this technique

prohibitively expensive on most large lakes, but aredging as

a restorative method has been used successfully for years on

small lakes and ponds.

    Nutrient inactivation in lakes is accomplished by adding

some type of material to the water that will bond witn,

adsorb or otherwise render nutrients unavailable to aquatic

plants.  Alum, sodium aluminate,  fly ash arid various other

materials have been investigated as nutrient inactivation

agents.  Although some pilot lake results with this

technique have been encouraging,  its applicability on a

large scale has not been determined.

    Under certain conditions the water quality of lakes can

be improved by diluting or replacing the existing lake water

with water of a higher quality.  This technique has been

used successfully in Green Lake, Washington and a few

others.  Its applicability is limited to lakes with reauy

access to a large supply of high quality water.

    Covering of bottom sediments with sheeting materials or

particulate matter is being investigated as a means or

preventing nutrient exchange and retarding rooted plant

growth.  Limited experiences with this technique have

encountered problems with ballooning of sheeting and

rupturing seals of particulate matter when gas is produced

within the sediments.  Investigations of this tecnnique in

pilot lakes are continuing.

    It is sometimes possible to replenish the oxygen supply

of anaerobic bottom waters of eutrophic lakes by disrupting

the thermal stratification or by aerating the hypolimnion

directly without disturbing the thermal regimen.  Definite

improvements in water quality and in the biota have occurred

as a result of artificial destratification and hypolimnetic

aeration.  Although the response ot a given lake to these

treatment measures is unpredictable, destratitication and

hypolimnetic aeration are potential mechanisms for improving

the water quality of certain lakes.

    Lake drawdown has been investigated as a control measure

for rooted aquatic vegetation, as a means of retarding

nutrient release from the sediments and as a lake deepening

mechanism through sediment consolidation.  Drawdown tias

shown promise as a successful remedial method in Florida,

but results in Wisconsin are inconclusive.  Lake drawdown

studies are continuing.

    In many lakes in advanced stages of eutrophication

attempts have been made to control nuisance organisms

through mechanical, biological and chemical means.

Mechanical harvesting can be an effective technique for

removing excess aquatic plants, but it generally is not

economically feasible on a self supporting basis due to the

limited market for the product.  Biological control agents

for algae and macrophytes range from the viruses to the

manatee.  Although certain organisms have proved to be

useful control agents, much work with biological control,

particularly with the viruses,  needs to be undertaken before

it will have universal application.   Various chemicals have

long been utilized to control or eliminate unclesired aquatic


flora and fauna.  Chemical agents, however, offer only
temporary, symptom suppressing relief, and often the

treatment must be repeated to achieve the desired results.

    Contamination of lakes with various hazardous substances

is an ever present threat.  In order to avoid major

catastrophies resulting from spills, industrial accidents

etc., measures for the control and removal of hazardous

materials must be implemented.

    Decontamination of lakes polluted with toxic substances

has been accomplished by filtering the lake water through

activated charcoal filters.  Several means of removing

mercury from waters and sediments have been proposed and

used in the laboratory, but few have been demonstrated in

field situations.

    Several state and local governments have established

statutes dealing with various aspects of lake management and

rehabilitation as a means of protecting inland lake

environments, but explicit statutes authorizing specific

state or  local programs are often badly fragmented among

state agencies and local units of government.

                         Section II


    An ever increasing rate of deterioration in tne

of the Nations's waterways combined with increasea puulic

need for clean water, has resulted in a public awareness of

the Nationfs water quality problems and a demand that action

be taken to alleviate the problems.

    The pressing need fcr sound water quality management

programs has resulted in the enactment of the Federal water

Pollution Control Act Amendments of 1972 designed to restore

and maintain the chemical, physical and biological integrity

of the Nation's waters.  Included within this Act is trie

requirement that "...The Administrator[of the Environmental

Protection Agency] shall, within 270 days after the

effective date of this subsection  (and from time to time

thereafter)  issue such information on methods, procedures

and processes as may be appropriate to restore ana enhance


the quality of the Nation•s publicly owned tresh water

lakes" - Subsection 30<*(i), PL 92-500.

    This report, prepared pursuant to subsection J04(i),

PL 92-500, provides background information on lake

environments followed by state-of-the-art information on

remedial measures for enhancing and restoring the quality ot

lakes, ponds and reservoirs as required by the legislation.

Discussion of major lake problems is included in an

appendix.  Since most lake restoration techniques are

presently in experimental stages, it is impossible to

provide a thorough evaluation and complete cost-

effectiveness analysis at this time.  However, as the

experimental programs now underway are evaluated and as new

technology becomes available, subsequent reports documenting

the latest technological and scientific achievements

relating to lake restoration will be forthcoming.



    The limited number of publicly owned fresh water

in the United States combined with increasing population arid

industrial pressures are major factors contributing to tneir

unique and widespread water quality problems.  Discharges or

organic and inorganic wastes resulting from urbanization,

cultural and technological advancement, and new water

dependent industries have caused noticeable degradation ot

lake environments in many areas.  The problem, in National

perspective, presents a complex interrelationship of urban

development, industrial growth, potable water supply

demands, recreational needs and maintenance of virgin area


    Aesthetic and environmental considerations aside, tne

demand for clean lakes for private, public, and commercial

use is of vital economic concern.  Design of a successful

water management program depends upon an understanding ot

the impact of man's activities upon fresh water environments

and the means of ameliorating harmful processes.

    Effects of waste discharges on the quality of tne

aquatic environment may be manifested as subtle long term


changes in the fauna and flora or dramatic and seemingly

immediate as in the sudden appearance ot alqal blooms,

aquatic weeds or dead fish.  Along with the alterations ot

the species composition of the animal or plant lite, snitts

occur in population densities with the ascendence or large

populations of often undesirable species.  Sports tisn are

replaced by "trash" fish, clean water associated bentnic

organisms are replaced by sludge worms and other pollution

tolerant forms, and the normal phytoplankton crops are

replaced by large populations of scum formina blue-green

algae.  In addition, human health becomes threatened due to

the establishment of pathogenic ir.icroorganisrcs associated

with fecal and other waste discharge.

    Reduction ot water related activities follows alteration

of aquatic life.  Boating, swimming, and water skiing

activities must be halted as lakes become choked with

aquatic weeds and as surface algal scums develop.  Economic

losses result from a decline of commercially important

aquatic species and with the curtailment of water related

recreational activities.

    Industrial and municipal water supplies are also

aftected by water quality degradation.  Industrial raw water


often must be treated to the desired quality.  If water is
uncontaminated, costs of water processing decrease, possibly
affecting final consumer cost.   Toxic materials and
pathogenic microorganisms in municipal raw water supplies
can affect health and increase the costs of processing.  Tne
taste, color and odor of water often make people reluctant
to draw water from contaminated sources.  In effect, tnis
limits water supply and increases the costs to the consumer.


                        Section III

                     LAKE ENVIRONMENTS

    Lakes are temporary features of the landscape, nearly

all of which are very young on the geological, but very old

on the human, time scale.  With the passage of time, all

lakes presumably would cease to exist as a consequence of

natural physical and biological processes.  Under natural

conditions these processes would require several hundreds or

thousands of years.  With the appearance of man on the scene

and as a result of his activities, however, these processes

have been accelerated dramatically, and the maturation or

aging rates of many lakes have been signiiicantly increased.

    In the discussion which follows, the limnological

aspects of lake environments including chemical, physical

and biological phenomena are briefly explored.  A general

understanding of the lake as an ecosystem is prerequisite to

an appreciation of lake problems.



    Often lakes are formed by some geological event sucn as

subsidence, faulting, damming of river valleys or by tne

eroding and damming action of glaciers.  Natural la*ces are

usually formed in infertile basins with low potential tor

biological productivity.  Thus they are generally poor with

respect to dissolved nutrients and biological production in

their early history, becoming more fertile with time as

nutrients are carried in from the drainage basin.  Man-made

lakes (reservoirs) are frequently created by the inundation

of highly fertile river valleys rich in nutrients necessary

for b'iological production.  Such reservoirs which have been

created in fertile areas will usually exhibit an immediate

high degree of biological activity which, if nutrients are

not constantly carried in via tributary streams or other

runoff,  will decline after a few years as nutrients are

accumulated in the bottom sediments or otherwise become

biologically unavailable.  Many reservoirs, however,  are

created by the confinement of rivers with very hign nutrient

concentrations which,  through contaminated inflow,  maintain

the fertility and productivity of the impoundment.


    In glaciated North America, nutrient-poor melt waters

filled ice-formed basins, creating lakes of various sizes,

shapes, and depths.  Many of these lakes, particularly

large, deep ones, have changed relatively little since their

formation and still retain their nutrient-poor

characteristics.  Such lakes, low in dissolved nutrient

content and biological production are of the type classified

as. "oligotrophic".  Oligotrophic lakes are characterized by

deep basins with large volumes of deep  (hypolirnetic)

waters, low organic and nutrient content, high dissolved

oxygen concentration at all depths throughout the year, and

low biological productivity.  Phytoplankton crops are

quantitatively restricted, represented by many species of

diatoms and green algae.  The deep bottom fauna is

characteristically sparse and is represented by such forms

as fingernail clams, crustaceans, insect larvae and

segmented worms.  Cold water fishes such as the salmonids

and whitefish are typical of oligotrophic lakes.

    llany other lakes, usually smaller and shallower, are

rich  in dissolved nutrients and are hicrhly productive.

These  are "eutrophic" lakes.  In eutrophic lakes organic

content of the sediments and the water column is high and

nutrients are abundant.  Oxygen depletion may occur


•seasonally in the deeper portions.  Diatoms,  green,  and

blue-green algae are the major phytoplankton  types,  with

seasonal shifts in dominance usually apparent.  During the

suiiror, Mue-green algae J: loops nay occur regularly, often

in nuisance quantities.  The bcnthic organisms of the.  deeper

waters consist of npecics which are able to survive  in  tho

low dissolved oxygen concentrations which occur

periodically.  Tubificid worris and ridge larvae may  be  very

abundant.  Fish populations usually consist of warm water

species such as perch, pike, bass, panfish, and bullheads.

These lakes eventually succeed into ponds, marshes or

swar.ips, and thence to dry land (Fig. 1).

    The distinctions between oligotrophic and eutrophic

lakes is sor.etines not sharply delineated, and the term

"mesotrophic" is often used to describe lakes which have

characteristics of both.  Many of the nation's better

recreational lakes are in a state of mesotrophy, having

evolved through their oligotrophic state to the point where

they are roderately productive but have not yet developed

nuisance conditions.

               M esotrophlc Lake
Ollgotrophlc Lake
                     Eutrophlc Lake
                                    Pond,Marsh or Swamp
                                                              Dry Land
          Figure i .—Eutrophfeation  -  the process  of aging
                             by ecological  succession.



    The thermal regimens of lakes exert a profound effect

upon overall lake ecology, primarily because of tne

associated phenomenon of thermal stratification.

    Seasonal changes in air temperature induce changes in

water temperature resulting in a cycle of events of mixing

and stratification which controls the dispersion of

nutrients and dissolved gasses throughout the water column

thereby affecting the biological activity in the lake

(Fig, 2).

    During the winter, surface water under ice cover ana

frequently open water are very near 0 C.  Since water

reaches its maximum density at 4 C, the warmer, denser

waters will occur at the bottom of the lake.  This is

inverse stratification.  With the gradual warming ot surface

waters in the spring of the year, the lake becomes

homothermous throughout at a temperature of 4 C.  Under

these conditions, winds generate mixing action whicn may be

complete from top to bottom even in very deep lakes,

distributing nutrients, dissolved oxygen and other materials

throughout the water.   As spring progresses into summer.


surface waters continue to warm, and a layer of rapidly

decreasing temperature called the "thermocline" or

"metalimnion" is formed, acting as a barrier which prevents

the warm upper "epilimnetic" waters from mixing with the

cool, deeper, heavier "hypolimnetic" waters.  The

hypolimnetic waters are effectively isolated from tne

overlying layers and the atmosphere, and if the volume ot

the hypolimnion is small and the oxygen consumption rate is

high, these bottom waters may become depleted of oxygen.

This tends to be the case in many eutrophic lakes.  This

condition will persist until the entire lake once again

becomes homothermous in the fall as the surface waters cool.

Mixing from top to bottom then occurs, and the bottom waters

are reoxygenated.  As winter progresses, surface water

temperatures again approach 0 C, and the inverse

stratification patterns are again established.

    Reservoirs are affected by all of the processes triat

influence natural lakes, and in addition, are strongly

influenced by the hydraulic effects of both the inflow and

discharge.  Reservoirs with high discharge to volume ratios

are often completely mixed during the summer due to the

rapid movement of water.  Deep reservoirs with a low

discharge to volume ratio often exhibit the classical lake


stratification cycle.  Operation of the reservoir aiscnarge

can have a major influence on the thermal structure.  i'ne

use of multiple outlet structures at various dep-tna can

provide pre-selected discharge temperatures when

stratification exists, which in turn provides modiLication

of the thermal regimen.

                               Figure 2
                   Diagramatic  sketch showing thermal
                      characteristics of temperate  lakes
                                     * J Metal imnion
  Spring  Fall
      Dissolved oxygen (mg/l)     Dissolved oxygen (mg/l)     Dissolved oxygen (mg/l)
O  2  4  6  8  1O 12 14  O2



E 3C

* 35
a 40
O 45




                                      6  8  1O 12  14
O  4  8 12 16 2O 24 28
     Temperature "C
                                 4   8  12 16 2O 24 28
                                  Temperature °C
                        2  4  6  8 1O 12 14
                        4  8 12 If 2O 24 28
                          Temperature °C
                         Inverse stratification



    Development of successful water management programs and

restoration planning depends upon as complete a knowledge as

possible of both the physical and biological processes

working within a particular system.  The turnover rates and

exchange of nutrients with the sediments are in p

governed by biological communities.
    Before proceeding, the term "nutrients" nust DC

because the definition of "nutrient" depends upon trie

individual involved.  "Nutrients" refer to not only organic

material, simple and complex, but to trace elements,

vitamins, and also the major inorganic elements: t>nospnor us,

sulfur, nitrogen and carbon.  For the sake of brevity, only

these four major nutrients are discussed.

    One nutrient which has received widespread attention is

phosphorus.  It is known that phosphorus can r r limiting to

phytoplankton and other organisms.  Most of the phos^norus

in the aquatic environment is bound in the seaiments as an

insoluble phosphate salt with availability of insoluble

salts being influenced by both the physical-chemical

factors (2) and bacterial metabolism (3).   As seen in

Fig. 3, loss or precipitation ot phosphates to the seuiments

and solublization of insoluble phosphates from the sediments

and exchanqe amonq the various biologic communities, is

mediated in part by the bacterial community (U - 10),  Three

general processes involved in phosphate solubility are the

direct metabolic processes involving enzymes, caroon dioxide

production leading to a lower pH, and organic acid

production  (11 - 13).  Inorganic phosphate is, in turn, used

by higher aquatic plants, zooplankton, and phytoplankton.

    As with phosphorus, sultur is cycled by the microbiai

populations in t.he aquatic environment and has been linked

to decreased product ivity_o_f fish  (see Fig. U) .

                                     FIGURE 3
                              PHOSPHORUS CYCLE
                                   SOURCE (14)
          Higher aquatic
Soluble  organic
              Bacteria         Inorganic
                      Loss to Permanent Sediments


    Sulfate can be stoichiometrically reduced to nydrogen

sulfide, which in turn can be oxidized chemically, in the

presence of oxygen, to elemental sultur.  Elemental sulrur

in turn, can be oxidized to sulfate.  A specific class or

bacteria, the anaerobic dissimilatory sulfate reducers, also

leads to the stoichiometric production of hydrogen sulfide

and consequent anaerobic environments.  On the other side

the oxidation of elemental sulfur by Thiobacilli leads to

•t-he production of sulfuric acid and their metabolic activity

is evident in the acid mine drainage in certain areas or the


    Biological nitrogen cycling involves, as does tne

cycling of sultur and phosphorus, the transition o± an

elemental nutrient through various cnemical states.  Fig. 5

is a schematic representation of the cycling of nitrogen.

It is convenient to initiate the consideration of the

nitrogen cycle at a point where fixation of gaseous nitrogen

occurs.  Relatively few species of microorganisms populating

the earth are capable of metabolizing nitrogen from tne air

 (16 - 19).  Once fixed from the atmosphere nitrogen is

converted by a relatively few species of bacteria ana blue-

green algae to organic nitrogenous compounds.

                                    FIGURE  4.
                             THE SULFUR  CYCLE
                                  SOURCE (14)
                           REDUCED ORGANIC SULFUR
                                IN LIVING MATTER
                      Plants  "^   Animals   "^  Bacteria
 Utilization of tulfote
(plnrts, microorganisms)
       Sulfir oxidation
  (colorless and photosynthetic
       sulfur bacteria)
     Bacterial decomposition
        of organic manor
                                     Desu If o vibrio
   Oxidation of HjS
(colorless and photosynthetic
    sulfur bacteria, or


    Subsequent to fixation the relative concentrations ot

the inorganic nitroqen compounds in water, i.e., nitrate,

nitrite, and ammonia, depend, in part, on the amount ot

oxygen available and the oxygen concentrations are dependent

upon the organic carbon load and seasonal variations in

solubility of oxygen in winter.  Attempts to develop a

nitrogen balance in lakes and other aquatic environments are

hampered by the fact that there are several possible sources

for loss of nitrogen.  For example, fixed nitrogen can be

lost via:   (1) lake effluents;  (2) loss of volatile nitrogen

such as ammonia and nitrogen gas;  (3) denitrification by

certain microbes;  (U) precipitation of nitrogenous compounds

into either permanent or semipermanent sediments; and (5)

removal of organisms by fishing, weed harvesting or otner

methods of fauna and flora depletion.

    The biochemical mechanisms  involved in denitrification

have only recently been elucidated in significant detail

(20 - 23).  These reactions result in the conversion of

nitrate to, ultimately, nitrogen gas and are apparently

unique to a limited group of microorganisms.

                   Figure 5


                 SOURCE  (14)
                   Htfecid Nitr«|tn

                   in wpiic Witltr
                                                                  (Mottly Mrvkic)
                                                                ic and ilkilint)


    The carbon cycle is composed of an integrated network of

physically and biologically mediated pathways encompassing

the synthesis, degradation, and transformation of

innumerable simple and complex organic molecules {Fig. 6).

Superimposed on the carbon cycle are the controls exerted by

nutrient availability, and the fixation and evolution of

carbon dioxide.  Various aspects of the organic carbon cycle

in the aquatic environment have been examined witn the

emergent principle that an overall balance between the

production, or synthesis, and decomposition of naturally

occurring substances exists in nature  (24, 25).

    Photosynthetic carbon dioxide fixation by green plants

is a major route by which carton enters the organic carbon

cycle.  However, fixation by autotrophic bacteria adds to

the total carbon budget in the ecosystem  (26, 27),  Once

organic material has been introduced into the aquatic

environment the endogenous flora and fauna can either

utilize or contribute to, depending upon conditions, an

existing reservoir of organic material  (28).  Some of trie

ecological questions relating to carbon arise when

considering the microbe's direct relationship to carbon

cycling are:  what effect does microbial synthesis of

complex molecules such as vitamins, amino acids.


carbohydrates, and lipids have on the aquatic biota; wnat  is

the contribution of bacterial biomass, a food source for

zooplankton; and what is the significance of microbial

degradation of suspended soluble or sedimented organic


    Direct and complex relationships between diverse

organisms have evolved based on the needs for various growth

factors.  Examples of these relationships are seen in tne

association of various algae and bacteria in the marine and

fresh water environments (29 - 32).  Also,  the degradation

of complex, naturally occurring organic compounds such as

chitin are affected by the microbial species.

    Microbial metabolic activity affects the cycling OE trie

four major inorganic nutrients under consideration.  The

cycling of each of these nutrients - phosphorus, sulfur,

nitrogen, and carbon - is interrelated in that any

perturbation in one cycle has far reaching effects in the

other cycles.  For example, it has been shown that tne

sulfate reducing bacteria are capable, not  only ot nitrogen

fixation, but of degradation of carbon compounds to carbon

dioxide and also of effecting a solubilization of phosphate

as a consequence of precipitation of insoluble iron sulfide

                             32  This is but one example.   Thero  are  inariy

examples of these interrelationships of  microbial

communities with higher  fauna 1 and  floral communities  and

with water quality.

                          FIGURE 6


                         Section IV



                        OWNED LAKES
    Lake restoration technology is in its infancy,  only a

few lake renewal proqrams have proved successful, ana these

only on individual lakes.  A method of lake rehabilitation

which may be hiqhly successful on a qiven lake, may oe

totally impractical or unworkable on another.  Eacn lake nas

its own peculiar characteristics, differing from all others

geographically, morphologically, chemically and biologically

as well as in the nature of its problems.  Consequently, it

is impossible at this point in time to recommend remedial

measures which will prove to be effective for all lakes or

even particular classes ot lakes.  It is t.he responsibility

of lake managers to define the problems and to implement

rehabilitation or enhancement programs which are oest tittea

to the requirements of particular lakes on a case-by-case



     This  section presents information on possible rei.ieaiax

 measures  which have been cr  are presently being appliea in

 lake rehabilitation prcqrams or in some cases are oeirig

 evaluated in the laboratory.   Many techniques are currently

 in  experimental stages on small lakes,  and the results are

 inconclusive at this time.   Other  techniques  have met with

 varying degrees of  success on individual  lakes,  but tneir

 applicability to other lakes  is unknown.

     Since eutrophication poses the greatest threat  to the

 Nation*s  lakes, this report  focuses primarily upon  tnose

 remedial  measures which may  be applicable to  certain

 displaying symptoms of accelerated or man-induced

 eutrophication.  Possible remedial measures for  la*es

 contaminated with industrial  wastes including toxic

 substances and hazardous materials are  only briefly

 discussed.   Subsequent reports will deal  with these problems

 in  greater detail.   Solutions to problems associated with

.thermal discharges  to  lakes are not addressed in this

 report.   Thermal discharge control technology is to be

 addressed in a forthcoming EPA publication as required  by

 Section 10U(t)  of the  Federal Water Pollution control Act

 Amendments of  1972.

    The approach to the rehabilitation of  deqra de.i  ic».s.Ob  is

    fold:  (1) by restricting the  input of  unaesirdL/ie

materials and  (2) by providing  in-lake treatment  ror trie

removal or inactivation of undesirable materials.

Obviously, the only means of mair^aininq the;  juulit/ 01 a

lake once dasired conditions are  achieved,  i:-3  i.y

restricting  the  input of undesirable  materials.   In

iakes reducino or ^liminatina the primary  sources or waste

loading is the only restorative measure neeaea to acai^ve

the desired  lev°l of improvement.   Oner the source  of

pollution  is abated, natural flushing and  dilution  wit.i

uncontaminated water may result in substantial imt'rovcineiitJ

in the quality of the lake.  However, in many  lakco,

particularly in  hypereutrcphic  lakes  with  slow flushing

rates, in-lake treatment schemes  may  also  he required  bcrore

significant,  improvements will he  realizeo.   In-lake

treatment  alone  without controlling pollutional intiows

cannot be  termed a restorative  measure as  only tho  b>mptoms

or products  of eutrophication and pollution are treareJ ana

no permanent improvements in quality  are achieved.   In any

lake restoration program, controlling the  input of   '

undesirable  meterials is the initial  step  towards p

lake rehabilitation; all ether  remedial measures  are

supplementary  to this action.


    In the following discussion, measures which may be

effective in the restoration and enhancement of tne Duality

of lakes are addressed under tour irajor headings as ruliows


         A.    Point source nutrient removal and control

         B.    Nutrient diversion

         C.    Control of allocthoncus sediments


         A.    Dredqinq

         3.    Nutrient inactivation

         C.    Dilution and dispersion

         D.    Covering of sediments

         E.    Artificial destratification and

              hypolimnetic aeration

         F,    Drawdown

         G,    Harvesting nuisance organisms

         H.    Biological control of nuisance organisms

         I.    Chemical control of nuisance organisms


Point Source Nutrient Removal and^Controj.


    Domestic wastewater represents a siqriticant source of

aquatic plant nutrients and therefore  is the source  tnat  is

often considered first for control.

    Conventional waste -treatment systems usinq  sedimentation

and activated sludge or tricklinq filters  remove only

suspended and dissolved solids and a portion of trie

nutrients.  Although these systems serve to reduce tne BOD

load to receiving waters, they generally remove less Lhari 50

percent of the phosphorus and nitrogen (33).

    The technology is presently available  to remove  i;otn

phosphorus and nitrogen from vvastewater at a moderate cost.

Phosphorus removal efficiency of 80 to 95  percent can be

achieved by cheirical precipitation with alum,  lime or ferric


salts.  Removal of ammonia and other nitrogen species  can  be

accomplished by ion exchange, ammonia stripping at ni.jn  yii

in a gas stripping tower, breakpoint, chlorination or

bacterial denitrification.

    Advanced wastewater treatment  (AWT)  for nutrient, removal

probably represents the best method currently available  lor

curbing nitrogen and phosphorus input to waterways.  An

obvious limitation of advanced waste treatment is its

inapplicability to the treatment of most wastes from non-

point sources.  However, under certain circumstances entire

rivers which receive their nutrient loads from diffuse

sources may be treated prior to their entry into a lax.e.   In

Germany, it has been proposed to treat the entire Wannoaca

River using iron to precipitate the phosphorus.   Tne

Wahnbach, which forms the Wahnbach Reservoir, receives its

wastes primarily from agricultural runoff.

    The storage and disposal of waste materials  extracted in

advanced wastewater treatment plants add to the  total

treatment costs.  The concentrated sludge and liquid must be

disposed of in such a manner that the nutrients  do not re-

enter a waterway.   The practice of depositing sludge in

marsh areas and along waterways is ecologically  unsound.


However, the application of the sludge to cropland to

increase production is one beneficial means of disposal.

    Information on the cost and efficiency of varicus

advanced waste treatment processes currently in use in the

United states is presented in Tables 1 and 2.  Table 1

compares total costs and removal efficiency for various

nitrogen control processes.  Table 2 presents information on

average costs of phosphorus removal based upon 1971 data

compiled by Cecil  (3U).  From an examination of tnese data

it is apparent that although some processes are more

expensive than others, in most instances for comparable

levels of nutrient removal efficiency, the cost ranges

overlap.  The characteristics of the particular situation at

hand which influence the cost of the treatment process

include:  (1) the existing treatment facility, (2) required

water quality standards,  (3) use and character of the

receiving water, and  (U) climatic conditions.  Since

nutrient removal treatment systems are usually built as

modifications of existing plants, the most important single

factor influencing the selection of treatment processes is

the existing treatment facility  (35).

                                                            TABLE 1

                                          Comparison of Nitrogen Removal Processes a/
                                                     Removal Efficiency
                                              Estimated Cost
                                                C/3.785 ml
                                              (0/1,000  gal.)
                                    Wastes  to he
                                    Disposed of
Armenia stripping
Ion exchange
Breakpoint chlorination
Physical chemical
Physical chenical


Efficiency based on
ammonia nitrogen only

Efficiency and costs
depend on degree of

Reouires strict
process control

Requires some chemical
addition and large
land disposal area
a/  Data supplied by the Advanced Waste Treatment  Laboratory, National Environmental  Research Center, Cincinnati,  Ohio
~   and the Municipal Technology Branch, Technology  Division, Office of  Research and  Monitoring, Washington,  D.C.

                                            TABLE 2

            Treatment Plant, Operatinq and Maintenance Costs for Phosnhornn  Removal

                                  Treatment Plant Costs a/b/
Plant Size
   (1 mgd)
 37,854 m3/dav
   (10 mcid)
378,540 n3/day
  (100 mod)
Building and Structures

Process Equipment
    Aluminum salts
    Iron salts
  Capital Investment Costs in Dollars

15,000               40,000
                        Operatinq and Maintenance Costs  in  Dollars/day

    Aluminum salts
    Iron salts
     8f .50
Chemicals b/ and Sludge c/
Disposal Costs          ~"

80%  P  Removal
     Lime                         3C.50
     Aluminum salts               40.45
     Iron salts                   43.05

90%  P  Removal
     Lime                         6C.35
     Aluminum salts               53.70
     Iron salts                   56.10

Total  Daily Operating
and  Maintenance Costs

80%  P  Removal
     Liine                        102.70
     Aluminum salts              104.35
     Iron salts                  100.45

90%  P  Removal
     Line                        132.55
     Aluminum salts              117.CO
     Iron salts                  120.05
 a/  Source:   (34)
 B/  The use  of polymers  for improved  coagulation  is  included in  choriral  costs
 £/  Land disposal  is assumed


    In this country there are currently about  1200

wastewater treatment plants, planned or in operation, wnich

incorporate some degreee or AWT technology.  However, to

date there has not. been documentation evaluating AWT as <*

means of restoring a lake.  The EFA program at Shagawa Lake

(36) will possibly be the tirst thorough evaluation

documenting restoration of a lake by nutrient removal

through AWT of municipal wastewater.  Lake Tahoe and tae A^T

plant there have been studied for a number of years;

however, the plant effluent does riot enter Lake Tanoe but is

diverted to a reservoir outside the watershed.

    Several advanced wastewater treatment plants are in

operation in Europe but data documenting the effects on iax.e

restoration are incomplete.   Preliminary data on tne

Groifensee in Central Europe indicate that the  phos^norus

content stopped its upward climb aftor an AWT plant was

built to remove 90 percent of the phosphorus froir. the Uster

municipal wastewater (37).

    Other possibilities for removing nutrients  from a point-

source include spray irrigation, scil infiltration ana

culturing and harvesting algae or aquatic plants.  Spra>

irrigation of wastewater on land to facilitate  the growing

of crops results in two methods of nutrient removal.   It

ties up nutrients, particularly phosphorus, in  the soil, ana

it allows nutrients to be incorporated into a croL; tnat can

be harvested and removed from the watershed.

    This technique is presently heincr evaluated as «

nutrient removal technique  through an EPA grant at 1'lusK.etjon,


    Pennsylvania State University has shown that cro^s that

have been irrigated by wastewater effluent can  suustantialiy

remove nutrients contained  in the effluent.  (38) .  In the

upper 30.5 cm of soil the concentration of nitrate was

reduced up to 82 percent and phosphorus up to 99 percent.

    Studies in Oklahoma showed that grasses grown in

hydroponic culture tanks removed appreciable nitrogen  but

only slight amounts of phosphorus from secondary wastewater

 (39).  One drawback to the  spray irrigation technique  is

that, long term irrigation with water  high in sodium or other

metals could render a soil  unproductive it these materials

reach an undesirable concentration.


    Soil infiltration, whereby wastewater  is allowed  to move
through the soil, removes or qreatly reduces suspenued
solids, biochemical oxygen demand, microorganisms,
phosphorus, fluorides, heavy metals and other substances,
including nitrogen if the recharge system  is properly
managed (UO).  Peat is particularly good tor removing
phosphorus.  In an EPA study (41) it was shown to remove 95
to 99 percent of the phosphorus from secondary wastewater.

    Species of the bulrush, Scirjnis, have been used in tne
biological purification ot wastewater  (42).  Phosphorus and
nitrogen are readily taken up by these plants and periodic
harvesting of Scirjaus will remove the nutrients from tne
system.  The use of Scir^ilS to facilitate wastewater
treatment is being evaluated in Germany.

    The culturing and harvesting ot algae tor nutrient
removal have been evaluated.  EPA is presently evaluating
this technique at Firebaugh, Califcrnia, to remove nitrogen
from agricultural return canals that enter San Francisco
Bay.  in South Africa (43) culturing and harvesting algae
have been studied as a method of producing water suitable
for reuse from wastewater.

    Diversion ofters a possible restoration technique in

situations where the majority ot the incoming nutrienc luau

i? enterinn from specitic point, sources.  It has oetm used

as a technique to control nutrient input from muni cipdli ties

located around the perimeter of lakes.

    The major disadvantages include the following':

    1)   Monetary costs - the expense of installing tne

necessary collection system for many lakes may be


    2)   Environmental costs - diversion ot untreateu sewage

from a lake to another waterway may result, in the

degradation ot that waterway and the substitution ot one

problem for another.

    3)   Lake morphometry - If the lake basin is shallow,
nutrient exchange between sediment and water may recycle

nutrients to the extent that no recovery is discernible.


    4)   Ground water -  If the around water  inflow  is

significant with respect to total hydroloqic budget dnu  it

is high in nutrients, recovery will be very slew or no

recovery may occur.

    5)   Hydraulic residence time - The rate at wnica iiiga

nutrient water leaves the basin will affect eventual

Case Studies:
1 .  Lake Washington - Seattle^ Washington, USA^44 -
    Lake Washington at. Seattle is a former oliqo«-rot,nic

which rapidly deteriorated to a state of eutrophy, bur. w;;icn

in recent years has shown definite signs ot recovery.

    The lake lies in an elongate, steep-sided glacial trougn

with a maximum depth of 65.2 m, mean depth of 32.9 m ana a

surface area ot 8768 hectares (21,650 acres).

    Prior to 1963, Lake Washington received heavy nutrient

loading from eleven sewage treatment plants discharging


directly into the lake.  It is estimated that in  1957, 5o

percent of the phosphorus and 12 percent of tne nitrogen

entering the lake was from sewaqe effluent.  Extensive

Oscillatoria rubescens blooms were observed in  1955

indicating considerable degradation of water quality.  Tne

abundance of alqae was approximately  15 times greater in

1962 than in 1950.  Secchi disc measurements had  been

reduced from 3 meters in 1950 to about 1 ireter  in  19b3,

196U, and 1965.  Nutrient concentrations increased

dramatically.  Phosphorus increased from 0.009  mg/1  in 19 J3

to 0.475 mg/1 in the  1960»s, and nitrate from 0.170  mg/1 in

1933 to 0.475 mg/1 in the 1960*s.  Dissolved oxygen

concentrations reached zero in the deeper water strata lor

the first time in 1957.

    A series of steps was instituted  by Metro  (Municipality

of Metropolitan Seattle) in the late  1950's to  divert tne

sewage from Lake Washington and to build a series ot new

treatment facilities  which would discharge into Puyet sound.

Estimated cost for the project was about $120,000,000.  Tne

first, phase of the diversion was completed in  196J,  at wnicn

time approximately 25 percent of the  effluent bypassea the

lake.  In 1965, the effluent volume entering the  lake was

reduced to approximately 55 percent of the original  load.


and by 1968, the project was complete vvith approximately  100

percent of the effluent diverted.

    Improvement in water quality has been dramatic since

diversion was completed.  Phosphorus concentrations in  19o9

were 28 percent of the 1963 values and nitrogen

concentrations were 80 percent of the 1963 levels-  3ecchi

disc measurements have increased froir, 1.0 m to 2.8 m.

Chlorophyll levels have decreased to approximately 15

oercent of the mean winter values tor 1963, and noxious

blooms of blue-greens have been eliminated.

    Lake Washington has shown a significant improvement with

th*> diversion of spwacre.  A reduction of 50 percent in tne

phosphorus loading has greatly decreased the algal growth

and a significant increase in transparency has occurred.

Dat-a indicate that phosphorus is the controlling element

wi+-h respect to algal growth in Lake kashingtor: anu tne

results of the diversion illustrate this in a dramatic



2«  Lake Sammamish, Seattle, Washington, USA	(j*8]_

    .The outlet of Lake Sammamish forms the inlet to trie

north end of Lake Washington,  In  1968 the sewage was

diverted from Lake Sammamisn, but  recovery has not been

observed.  Approximately 65 percent of the total phosphorus

and 22 percent of the nitrate-nitrogen were diverted witu

the interception system.  Surface  nutrient concentrations,

algal activity, light penetration  and hypolimnetic oxygen

deficits have not changed.

    Although Lake Washington has shown a dramatic recovery.

Lake Sammamish has not.  Proposed  reasons for this include:

 (1) a greater exposure of epilimnetic waters to sediment in

Lake Sammamish  (65 percent more than Lake Washington),  (^)

the lesser state of eutrophication of Lake Sammamish at the

time of diversion,  (3) the possibility of funqi

 (actinomycetes) complexing phosphates and removing tnem from

the system, and  (U) ground water infiltration from urbanized

areas of the lake.  No experimental work has been conducted

on the first three proposals but the fourth alternative is

unlikely because intensive monitoring of the tributaries nas

failed to detect abnormally high phosphorus concentrations.


3.  Madison Lakes, Wisconsin, USA (45, 46, 49, 50)

    The city of Madison, Wisconsin is located between Lakes

Mendota and Monona, the first and second lakes in a series

of four on the Yahara River,

    All of the Madison Lakes have a long history of algal

problems, but Mendota has been the least troublesome.  Lakes

in this region are naturally productive, but the problems in

the Madison Lakes were attributed to urbanization.

    In the early history of the city, Lake Monona received

the sewage from the city of Madison.  As a consequence in

1912 algal growths had become so prolific that copper

sulfate was used to kill the algae,  and in 1925 a regular

program of treatment with copper sulfate was established.

The condition of the lake deteriorated steadily.  In 1928

the Nine-Springs plant was placed in operation and the

effluent from this operation was carried via Nine-Springs

Creek to the Yahara River downstream from Lake Monona.

    Algal productivity in Lake Monona was not measured

directly, but the quantities of copper sulfate used to


control algal growths may be indicative of the intensity of
algal crops.  Since relocation of the plant, the amount of
copper sulfate needed to prevent obnoxious bloons has
decreased dramatically.  A total of 1,579 kg (3,481 pounds)
was used from 1955 to 1963 as compared to 45,587 kg  (100,500
pounds) used in 1934 only.  A change in species composition
has also occurred.  The algae presently inhabiting the lake
do not cause surface scums, thus the need for copper sulfate
has diminished.

    The relocation of the sewage treatment plant did not end
the Madison Lakes' problems.  Shortly after the effluent was
moved  downstream  from Lake Monona, the symptoms of
overenrichment in Lakes Waubesa and Kegonsa began to
intensify and copper sulfate treatment in large doses was

    The community eventually adopted a plan by which the
effluent was diverted  from the Madison Lakes via the Badfish
River  to the Yahara  River downstream from the lakes.  The
diversion project was completed in 1958.  Since diversion,


the condition of the  lakes  appears  to  liavo  improved, out

Radfish River has deteriorated considerably.
    It is difficult to relate  the Madison  Lake  diversion

project to the Lake Washiqton  case,  because  the Mauison area

is much richer in dissolved minerals than  is the Lako

Washington area, and consequently the Madison Lakes are

naturally more productive.  In addition the  Madison LaKcs

are much smaller and much shallower  than Lake wasnin«jton

(see Table 3) .
                          TABLE 3

           Length        Width         «Area,  .  deptn,  deptn,
Lake   	km    (miles)  km	(miles)  km     (mi)      m       m
Mendota  9.5    (5.9)   7. U   (U.6)   39. 4   (15.2)   2b.62   12.1
Monona   6.7    (4.2)   3.9   (2.4)   14.1   (5.U)    22.b7    8.4
Waubesa  6.8    (4.2)   2.3   (1.4)   8.2   (3.2)    11.16    4.9
Kegonsa  4.8    (3.0)   3.6   (2.3)   12.7   (4.9)     *.b8    4.7


U.   Red Lake	(Rotsee)t Lucerne. Switzerland  (U5)

    Sewaqe was diverted from Red Lake  (Rotsee) in 193J, but

the lake continued to produce nuisance quantities or aigae.

The reasons for the lack of improvement in Red Lake

following diversion are attributed to the lake*s small size

and .the considerable drainage it receives from fertilized

and cultivated cropland.
5.  Lvngby-So, Copenhagen. Denmark	(45)

    The sewage was diverted from Lynqby-So in 1959 and

productivity, as measured by the rate of photosynthesis,

decreased markedly for the next four years.  The submerged

rooted aquatic vegetation disappeared from the lake after

1956 presumably from shading by algae, but the aquatic

macrophytes are now becoming reestablished.  It appears in

this case that recovery began immediately.


6-  Stone Lake^ Michigan, USA  (51)

    Stone Lakp which has a surface area of  56.6 hectares

(140 acres) began to receive  secondary sewage in  1939.  fne

treatment plant was replaced  in 1965 and the treated wastes

since then have been disposed of outside the drainage Dasiri.

The only remaining sources ot pollution are a few nousenold

septic tanks located on the periphery of the lake.  The lake

has shown little response to the cessation of nutrient

influx from the treatment plant.

    Several reasons are suggested for the failure or tne

remedial technique.   Although over 95 percent of tne

phosphorus and 50-75 percent of the nitrogen were removed,

some pollution is still entering the lake (organic

materials).  Because of the relatively shallow morphology

(mean depth 6.1 m.)  sediment-water nutrient interchange may

be responsible for recycling previously deposited materials.

Further, hydraulic retention time is of such a magnitude  (11

years)  that insufficient time has elapsed to observe

significant improvement in water quality.

    Lake Anriecy was classified in  1937 as  "becoming

eutrophic".  Conditions became more pronounced with  time

because of human waste disposal to the lake.  Low  aissolvea

oxygen became the norm and  species composition of  tne

phytoplankton indicated an  advanced eutrophic state  during

the 1960's.  In  1961, a diversion system was begun.  By  1971

approximately U4 percent cf the population around  tn-a

periphery of the lake was using the system.

    Changes in algal composition indicate  that the water

quality of the lake is improving, tut the  studies  nave not

been carried on  long enough to determine the long  term

8•  Diamond Lake, Oregon, USA  (53)

    A sewage  interceptor  system  has  been  installeu  around

one-half the  periphery  of  1,9ttU  hectare  (U,800  acre)  Diamonu

Lake.  The lake  is  primarily used  for  trout  fishing,  and

extensive camping,  lodge  and summer  home  facilities are

located around the  circumference.  The U.  S.  Forest Service


installed a waste collection system to replace existing

septic tank systems in 1971, but it is not as yet tuliy

operational.  Studies have been made to obtain background

data on the chemical, physical and biological

characteristics of the lake.  These will be monitored in the

future to determine changes in water quality.
9a	Lakes Teqernsee and Schlicrsee  (5U)

    Sewage diversion  (finished 196U/65) from two Bavarian

lakes (Tegernsee and Schliersee)  resulted in a reduction or

the phosphate load to the lakes to about 10-20 percent or

the former amount while nitrogen income was diminished to

about 25-UO percent.  In 1967 improvement was observed,

especially with better hypolimnetic oxygen conditions at

summer stratification.  Subsequent years, however, showed a

relapse in the highly eutrophicated Schliersee to oxygen-

free hypolimnion again, while improvement at the 1'egernsee

was more or less maintained.  Intensive remobilization of

nitrogen and phosphorus from lake deposits permanently

increased nutrient levels in the Schliersee up to 1*70.  A

partially meromictic  (permanent stratification)  situation

seems to be mainly responsible for this process.  Different


circumstances which may promote or restrain improvement

after sewacre diversion include hydroloqical and climatic

conditions, progress of eutrophication at the moment of

sanitation, and intensity of nutrient-turnover.

Notwithstanding eutrophication parameters, sewage diversion

has removed primary pollution of *"-he lakes and their

tributaries which is of great importance for their

recreational function.
Control of Allochthonous Sediments

    Sedimentation of lakes and reservoirs is a major factor

restricting the available acreage of the Nation's

recreational waters.  In terms of volume, sediments are the

greatest pollutant.

    Sedimentation rates in lakes and reservoirs can

freguently be retarded by prudential land use management

practices within the watershed.  Construction and logging

activities should shun the steepest slopes, arid projects

which denude the landscape should be timed to avoid seasonal

rainy periods.  Agricultural practices such as strip

cropping, contour plowing, and proper grazing practices


prevent rural erosion  and  con sequent  sed iron tat ior in

streams and lakes.   Terraced  hillsides  and  banlrs  of

watercourses stabilized by riprap  or  gabionr,  are  also

effective erosion preventive  reasnres.
Sedirent Traps

    Gedirents ray sonetires be trapped before  they  enter

lakes and reservoirs by filter darns and. desilting basins

installed dov.T.strean froii all larae cleared  areas and  other

sources of silt.  Detailed descriptions of scdirent traps

and their use as well as other effective  srdii ont controls

may be found in the publications by Throrson (55) and  the

national Association of Counties Research Foundation (56).
Analysis of Sedirent Transport

    The mechanics of sedirent transport have b

extensively studied and hydraulic and nathenatical r,od<=l

studies of bedload and suspended load transport  are

described by Eogarci (57) .  Three stages of statistical


analysis can be recognized in sedimentology  (56).  Tne first
stage is descriptive statistics in which the sample is the
object of interest.  The second stage is analytical
statistics in which the population is the object of
interest.  The third stage is the application of stocnastic
process models in which the objective is to discern the
probabilistic elements in sedimentary processes.  Krumbein's
paper, as abstracted in Selected Water Resources Abstracts
by the U.S. Department of the Interior, states  (58),
"Stochastic process models thus provide one way of examining
sedimentary processes through time or over an area.  In
conjunction with deterministic models they provide a
framework for exploring the underlying physical, chemical,
and biological controls on sedimentary processes and
deposits...."  Using turbulent diffusion theory  (59) a rion-
steady-state model was developed for sediment transport.
Cost Effectiveness Models

    The economic benefits  to be gained by controlling'
erosion and sedimentation  are compared to the control costs
in a cost effectiveness study.  Such a study on the Seneca
Creek watershed, near Washington, D.C.  (60) compared cost to


effectiveness and damaqe values for many sediment control

methods.  Present control practice includes sediment oasins,

diversion basins, level spreaders, grade stabilization

sr.ructures, sodded ditches, seeding, and straw muicn t-acKed

with asphalt or disked.  The average conventional system is

estimated to cost $2780/hectare and to control 91A of cne

potential erosion.  Control systems incorporating large

sediment basins can boost control to 96% at less total cost.

Economic aspects ot sedimentation are also discussed £>y

Maddock (61).

    Many lakes have suffered the consequences of filling arid

nutrient enrichment as the result of allochthonous materials

entering from the watershed.  Highly eutrophic also

receive large amounts of autochthonous materials resulting

from massive algal populations.  Much of the organic

material entering the system will not be decomposed oecause

of the low oxygen conditions in bottom waters associated


with increased productivity.  The eventual resul^  is an

accelerating rate of sedimentation and a  fillinq or tne iakt1


    Dredging has thus been  proposed as a  possible  remedial

technique.  This would serve to reprove the sedimf-nt build-

up, thus increasing the depth of the  lake, and  removing a

potential nutrient source.  A large number of lakes nave

been dredged but no information is available on the cnemical

or biological effects.

    A number of disadvantages are obvious with  respect, to

this technique:

    1)   The relatively high costs cf dredging  operations

may make this technique prohibitively expensive on large


    2)   The dredging operation may release nutrients from

the sediments, making them  available  for  reinvolvement in

the food web.  The nutrient content of many sediments may

remain  high at considerable depths, making it impossible to

reach a low nutrient  level  in the sediment.


    3)   The elimination of shallow zones which maintain

large macrophyte beds, may result in a considerable increase

in the algal populations.  The nutrients formerly tiea up  in

macrophyte biomass could become available for algal growcri.

The result may be the substitution of one problem for a


    U)   Turbidity resulting from the dredging process may

persist for a considerable time during and following


    5)   Disposal of the dredged spoils economically is

often impossible.  Sediments iray prove unsuitable for

agricultural purposes and in such a case, could be used ror

land fill only.

    6)   Interstitial waters contained in sediments are

frequently high in nutrients,  consequently,  disposal of tne

sediments must be in such a manner that leeching of nutrient

rich waters back to the lake is prevented.

Case Studies:
1 •  Lake Truminen, Vajko, Sweden _ [62J.
    Lake Trummen is a shallow  (1.1rri mean depth) small  (1.0

km )  lako located in central south Sweden.  The IdKe is one
of a series of oligotrophic lakes, indicating that

Trummen was also once oligotrophic.  Waste water has entered

the lake since the turn ot the century resulting in a nignl>

eutrophic condition for many years.  Studies indicate that a

20 cm layer of black, hiqhly organic qyttja has been

deposited since human habitation Legan around the laKe.

    Plans were instituted in 1966-67 to develop some type ot

restoration program.  The final decision has been to dredge

to a depth sufficient to remove the recent gyttja deposits,

and to dispose of these materials  in bay areas of tne lake.

An estimated 600,000 n\  of sediment will be removea.  Tne

water released from the sediments  upon their deposition on

land will be treated with aluminum sulfate to remove

phosphorus before it is allowed to reeriter the lake.   /


    The Lake Trummen study is extremely comprehensive,

involving individuals from at least sixteen disciplines


relating to water quality management.  Data have  been

collected for two years prior to th<=> study, and wiii ne

collected during the 2-year dredging operation.   Thu

will be monitored for 8 years after completion or  t-ae

dredging.  Dredging operations were to begin in 1-J70,  out.  no

information is yet available.
    A suction type dreage was used to remove silt rroui

eutrophic Lake Herman.  Analytical results in.iicat.ei cnac

water trom the drela^d material when it returned to tae iaKe

was lower in pH and total phosphates, and almost as cleat us

the lake water.  Total orthophosphate-phosphorus i

dramatically in the lake water (approximately dou^

during dredging, but the concentrations of the o

nutrients remained at approximately the same
The following synopsis is taken from Technical Bulletin

Number U6, Inland Lake Drodging Evaluation, Depart :n^at ot

Natural Resources, Madison, Wisconsin (6U) .  Very general

data are presented and none ot the lakes appear to have ueen


investigated to determine water quality changes associated

with the dredging operations.
3.  Wazeecha Lake^ Wood County, Wisconsin  USA

    The upstream end of LaKe Viazeecha, a 60 hectare  (148

acre) impoundment of Buena Vista Creek* was dredged  by  trie

County over a four to five-year period.  The dredgeu area

was deepened by 1.2 to 1.5 m by the  removal of  133,530  m° oi

sediment.  The total cost of the operation, including tiie

purchase price of a second-hand 19.6  cm hydraulic  cutternead

dredge was $66,859, at a unit  price  of $0.50/m^ (4>U. Jd/yd^) .

The dredged spoil was pumped onto  the shoreline, improving

the conditions of the shoreline.   One area was  diked off and

filled, and a new park was created on the  fill.
^-  North Twin Lake.  Calhoun  County,  Iowa  USA

    North Twin Lake,  a  207  hectare  (510  acre)  lake  in  the

predominately agricultural  plains country  of west central

Iowa, had undergone rapid sedimentation  resulting from

severe bank  erosion and sheet erosion from the surrounding


farmland.  The lake had been tilled with as much as four

meters of sediment, reducing the lake depth to 0.6 to  0.9  in.

Dredginq first beqan in 1940 when 55 hectares  (13b acres)

were dredqed to a depth ot U. 3 to 5.5 n-.  Dredging was  tneri

discontinued until 1960 when five dredqing contracts were

let to private contractors.  Durinq the 1960*s the entire

lake beyond U5 m from the high water line was dredged  to a

depth of 3.7 to U. 3 IT, removing 1,S23,U98 m^ of sediment.

The project was completed in 1969 at a cost, of $934,931.

The dredging was done by two contractors, one using a  JO.5

cm and the other a 35.6 cm cutter head.  The contractor using

the larger cutterhead excavated approximately 0.6 as much

material in a period of U months as the other contractor did

in six years,  Kis total unit costs, including dike work,

were estimated at $0.52/m^ ($O.UO/yd^)  of excavated

material, whereas combined unit costs for both contractors

                3          ?
averaged *0.61/m  ($O.U7/yd ).   The unit costs do not

include administrative and engineering expenses.

    Benefits to the lake,  other than increased water depths,

have not been defined as yet.


5.  Lake Ceorge and Lake Sisseton, Fairmont, Minnesota USA

    Lake George and Lake Sisseton are in a chain of  five

lakes located within Fairmont, Minnesota.  The  city  draws

its municipal water from these lakes, and their eutrophic

conditon was contributory to hirrh water treatment plant

operating costs and a warn municipal supply.  In 19^6 the

city of Fairmont purchased a 30.5 cm portable hydraulic

cutterhead dredge and  appurtenant equipment at a cost of

about $175,000 for the purpose of dredging the  entire, chain

of lakes.  To date only Lakes reorge and Sisseton have? been


    Prior to dredging, water depths  in the lekes averaged

1.8 to  2.0 IP.  The lakes were dredged in all areas beyond  4f>

m fron  the high water  line, sloping  down to a maxirun depth

of 7.6  n or until a hard suhstrata was reached.

    Dredged materials  from Lake  Sisseton were deposited  on

an adjacent city-owred 69 hectare  (170 acre)  fan".   The

disposal site  is  sufficiently  larae  to pemit adernato

settling so that  the dredger. v;ater rkich  returns  to  the  lake

has a very  lov/ suspended  sclids  content.   The natcrirl


dredged from Lake George was pumped to a different disposal

site which is presently being developed into a park.

    It is estimated that 382,328 m  of sediment are dredged

yearly at a cost of $35,000 to $50,000.  Unit costs ot

dredged materials including engineering and administrative

costs, but excluding disposal site costs are estimated at

about $0.13 to $0.16/m3 ($.10 to $.12/yd3).

    Dredging is part of an overall lake improvement program

being undertaken in these lakes.   A complete sanitary sewer

system was also installed, and the combined effects have

reportedly been a marked improvement in water quality

although no quantitative data are available to support this

contention.  The benefits derived from the total project

include: greater water depths and volume,  lower water

temperatures, habitat improvement for fish and desirai>ie

aquatic organisms, a general increase in recreational value

and reduced water treatment costs.

    Additional information is given for several otner la«.es

which have been dredged, but the atove examples are

representative of hydraulic cutting head dredging

experiences in the Great Lakes Region.  A survey of

inland lakes and ponds indicated that contract unit costs

will usually vary between $0.59 and $0.98/nr  ($0.45 and

$0,75/yd^) When all costs are considered.  The major factors

determining costs are :  1) the project size, 2) tne type or

material to be excavated, 3) distance to disposal sites, and

U) the availability of properly equipped dredging

contractors.  Such factors as obstructions in the lakes such

as tree stumps and boulders, purchase cost of disposal site

(if necessary) and experience of the contractor can also

influence total costs.

    There is no information available on the total

ecological effects of dredging upon lake environments or on

the water quality.  Complete biological, physical and

chemical assessments of pre and post dredging conditions

need to be made on several  lakes with varying

characteristics before the benefits derived from dredging

can be thoroughly evaluated.


Nutrient Inactivation

    It has become apparent after some nutrient diversion

studies that nutrients may remain in the water tor several

years an 3 noticeable improvement in water quality may oe

delayed.  This seems to be particularly true of laxes wnicn

have practically no water flow- through tc replace tnat

which is high in nutrients.  A possible alternative to

simply allowing the lake to remain in a highly eutrophic

state, is to attempt some method of nutrient inactivacion.

This process can be defined as the adding ot some type of

material that will bond with, adsorb, or otherwise

immobilize necessary algal nutrients, thus preventing tnein

from being utilized by these organisms tor their growtn.

    Present studies have been directed toward the most

common growth limiting nutrients,  phosphorus and nitrogen.

Phosphorus removal has been used in field studies on tnree

occasions, and some work has been done on a laboratory scale

using ammonia ion exchange resins.


    Many problems remain to be answered before this

technique can be considered operational.  A few ot tae more

obvious potential problems are listed below:

    1)    The relatively high expense of treating the ooay of

water may be prohibitive.  Materials may not in tnemselves

be overly expensive, but manpower necessary for application

and transportation costs may be considerable.

    2)    Possible toxic effects ty the introduction of an

excess of a metal used as a precipitant may have toxic

effects on the biota.

    3)    Adverse biological effects may result from trie

formation of a floe.  The material used may be non-toxic*

but the floe could conceivably suffocate aquatic organisms

by interfering with their respiratory mechanisms.  it is

also possible that the floe material resting on tne

sediments could interfere with the benthic ecology 01 the



    U)   In order to obtain maxirriurr effectiveness,  it.  may be

necessary to either raise or lower the pi: of the system,

which could have serious biological consequences.

    5)   The addition of certain salts, such as sultatea  and

chlorides, may increase the conductivity of t.he water  to  an

unacceptable level.  In the case of sulfate, if tne

hypolinmetic waters should become anaerobic after treatment,

reduction of the suitate would lead to the release ot

hydrogen sulfide.

    6)   Little information is available on the etfective

duration of the treatment.  Wind action, continued inflow ot

nutrients, bacterioloqical and benthic organism activity  are

a few of the phenomena which could possible influence  tjne

longevity of treatment effects.

    7)   The time of application of the inactivent may be

critical; it may be necessary to apply the material when  the

maximum nutrient content is present in the water.


Case Studies:

^-  Lake Langsjon, Stockholmj Sweden  (65. 66)

    Lake Langsjon is a shallow  (max.  3 m depth) , J5 nectare

(86.5-acre) lake which has received municipal waste,  ^ear

the end of April 1968, 30 metric tens of aluminum suitate

were added in an attempt to inactivate phosphorus.  The

final aluminum concentration was about 50 mq/1  of lake

water.  Immediate results included an increase  in seccni'

disc measurements from 50-60 to 250 cm, a reduction in total

phosphorus by approximately 50 percent ana a reduction in

phosphate  phosphorus by a factor of 12  (60 to less cnan  5

uq/1).  Total phosphorus increased during 1968, but a

concomitant increase in "thero-stalle" coliform bacteria

indicated  that municipal sewage was enterina the lake.

During  1969-1970, there was an increase in phosphorus levels

during winter stagnation.

    In May 1970, the lake was again treated with J2 metric

tons of aluminum sulfate.  Total phosphorus values were

reduced by approximately two-thirds  (170 ug/1 to 50 ug/1) .

During the summer of  1970, the phosphate phosphorus remained


about 30 ug/1, sliqhtly above the levels encountered  the

previous summer.

    The investigators concluded that the aluminum suit ate

was effective with respect to total phosphorus reduction.

There was also a slight improvement in dissolved oxygen

conditions during winter stagnation: The period between tne

formation of the ice cover and the development of anaerobic

conditions was extended.  They concluded, however, that the

effects of aluminum sulfate are net long lasting.  A

substantial increase in both phosphate phosphorus arid total

phosphorus concentrations occurred during the period of

winter anaerobic conditions.

    Following treatment, phytoplankton remained aoout tne

same with respect to total number of organisms but tuere was

a change in species composition,  with a general reduction in

the proportion of blue-greens.  No adverse effect, was noted

on the other biota, although little guantitative worx. was

done to verify this.


2-   Horseshoe Lake. Manitowoc Country, Wisconsin USA  (b7)

    Horseshoe Lake, an 8.9 hectare  (22 acre),  16.7 m deep,

eutrophic lake in east-central Wisconsin was selected for

treatment and evaluation.  The Lake was treated in May 1970,

by distributinq 10 metric tens of slurried alum in tae top

60 cm of water.  Alum concentrations  in the treated volume

were about 200 mq/1  (18 mg Al/1) , which, based on laboratory

testing, resulted in inaxirrum phosphorus removal with minimal

ecologic risk.  The results of the treatment include:   (1) a

decrease in total phosphorus in the lake, during the summer

following treatment,  (2) no large increase in  total

phosphorus in the hypolimniori during  the following two

summer stratifications,  (3) seme increase in the

transparency of the water during the  summer following

treatment,  (U) a short-term decrease  in color,  (5) an

absence of the nuisance planktonic algal blooms tnat naci

been common in previous years,  (6) marked improvement in

dissolved oxyqen conditions, especially during the toilowing

two winters, and  (7) no observations  ol adverse ecological

consequences.  Manpower, equipment and cost information are

summarized in Table U.

                               TABLF 4

       Summary of Manpower, Basic Equipment and Costs for Alum
              Treatment of Horseshoe Lake, Wisconsin. I/




Labor for Treatment

8 man hours per trip @ $5.00/hour
270 miles round trip @ $3.00 day
+ $O.C/mi.
12 samples per trip @ $30/sample
1 professional
10.88 Metric Ton Alurr @
$66.18/metric ton (12 ton @$60/ton)
Delivery to site
12 man days @$40/day
+ expenses
Costs 2/
S 7
Equipment List
2-18 ft. workhoats
2-10 ft.x20 ft.  baroes
4-outboard motors, 18-25 hp
1-amphibious truck, 21/2 ton,
4-gasoline driven pumps
1-4,000 watt generator
2-electric pumps
3-electric mixers
4-55 gallon slurry tanks
2-200 gallon slurry tanks
Piping, valves,  hose, plastic
     tubing, marker flags,  gasoline,
     plastic tarp, rope, dust  masks
essentially all
onuiprent was
on loan
I/  Source: (67)
    Many of the costs associated with this  treatment are  entirely
     dependent on local salary levels,  distances  to  site, sampling plan,
     magnitude of treatment,  and local availability  of eouiprent.
     In essence, treatment  costs must be  estimated for a  specified


3.  Clines Point—Oregon USA (68)

    A 0,4 hectare (1 acre) tarm pond with an average

of 2.4 m was treated with a neutralized solution o± sodium

aluminate.  A concentration of 10 mg Al/1  (3 mg/1 NaAl02)

was achieved by the adoption of 227 kg of sodium aluminate.

The aluminum compound was neutralized with hydrochloric acid

prior to its application to form an aluminum hydroxiue floe.

    The first year's results were encouraging.  Total

phosphate, ammonia, total kjeldahl nitrogen, iron and

manganese remained lower than in previous years, and tue

algal standing crop was reduced.  A shift in dominance from

blue-green to green algae was no-ted.  Dissolved oxygen,

transparency and pH also indicated a significant improvement

in water quality.

    Costs excluding labor were $100 for 227 kg ot sodium

aluminate and S60.00 for the hydrochloric acid.  It required

five people one full day to treat the pond.


*•  Twin Lakes. Ohio: Stone Lake, Michigan USA

    There are presently two demonstration grants funded by

EPA which anticipate the use of nutrient inactivation as a

lake restoration tool.  The one project at Twin Lakes, Ohio

will combine nutrient diversion and nutrient inactivation.

Nutrient diversion is presently being undertaken and plans

are to treat the lakes with alum (aluminum sulfate).  The

other project at Stone Lake, in southern Michigan, will

probably utilize fly ash and lime,  in anfattempt to

precipitate the phosphorus as well  as seal the bottom (5 cm

layer of fly ash in the deeper areas).  Laboratory studies

have been encouraging using this technique, but the possible

hazards must be weighed against anticipated benefits when

considering the application of fly  ash to lakes.

    Many metals have been suggested as possible nutrient

inactivation materials.  Lanthanium and zirconium nave been

investigated in the laboratory by the National

Eutrophication Research Program, EPA, with varying degrees

of success.  Other suggested metals include iron, calcium,

activated aluminum, bauxite and several of the rare eartns.

Clays which would serve as adsorption sites for the

phosphate and bottom sediments have also been suggested.


These would include such substances as bentonite,

montmorillonite and kaolinite.  Polyelectrolytes are also

feasible but their cost is so qreat that it may be

prohibitive.  Materials such as straw and sawdust have also

been used but the eventual decomposition of these materials

would be expected to create severe problems.  Their use

would be highly questionable.  Another possibility is the

resuspension of low nutrient bottorr sediment whicn would

absorb phosphorus as it resettled through the water column.

    Nutrient inactivation would have to be evaluated on a

lake-to-lake basis.  No universally acceptable substance has

been discovered which could be acceptable under all

environmental conditions.  Because the technique represents

the addition of a foreign material to the water it should be

used very carefully.  Long term effects on the biota or

water chemistry have not teen determined tor any ot the

substances  listed above.


Dilution and Displacement

    The water quality of some lakes can re improved cy

diluting or replacinq the existing water with water ot a

higher quality.  In usinq this method the replacement wat^r

must be readily available and there must he a convenient and

acceptable means of discharging lower quality water.  rtater

replacement can be done in one of two ways:  (1) uy

introducing high quality water directly into the ia*e, tnus

displacing an equal volume ct lower quality water or  (2)  b>

removing a given volume of the existing water and replacing

it with water of higher quality.
Case Studies

1.  Green Lake. Seattle, Washington UgA_J69j.

    The displacement technique has been successfully

employed in Green Lake, located in Seattle, Washington.

    Green Lake is a 104 hectare (256 acre) , nat.urally

eutrophic lake, with an average water depth of 3.8 in.

Sedimentation has been rapid in Green Lake, with an

estimated two-thirds of the volume of the basin filled with


sediment by the early 1900*s.  The present rate ot

sedimentation is about 0.9 cm per year, practically all of

which is autochthonous organic matter.  During the summer,

mixing of the entire lake is complete except for a very

small portion within the confines ot the 6 m contours, at

which depth thermal stratification persists.

    It is estimated that Green Lake has been eutrophic tor

7,000 years.  The blue-green algae production is very hign,

and rooted aquatic plants are abundant throughout the

littoral zone which comprises much ot the total area.

Herbicides are applied periodically to control rooted


    In 1962 water was diverted to the lake from trie city*s

municipal supply for the first time.  Between 196^ ana 19t>8,

the equivalent of approximately eight lake volumes of water

have been flushed through the lake.

    A comparison of pre and post flushing data indicates

that substantial changes in water quality have occurred

following the addition of dilution water.  Phosphate levels

have dropped considerably, particularly during August and

September when blue-green algae growths reach their peaks.


Decreases in nitrate nitroaon were  even  rore pronounced,

v;ith the naxinun  discrepancies occurring during r.idsumer.

    Since dilution definite  chancres in the species

composition of the phytoplankton  have been observed.  The

bluo-green alrrae  v/hich,  in 1959,  were doninant durina all

nonths of the year, were  the rest proninant form during only

5 or 6 months during 1905 and 19CG.  There has also } een a

shift anorignt the blue-areen alrrae  to those species wbich

are al^le to fi:: gaseous  nitrogen.   For e;:anple,

Aphanizonenon flos-aruae \;liich v;as  the najor nuisance alga

during 1951 has all but  disappeared fror« the laJ^e, and

Anabaena cirinalis and Gleotrichia  echinulata have increased

in abundance.

    further investigation of the  Green Lal'e situation ir;

continuing, and atterpts are heing  rade  to develop a Vinetic

r.,odel that can be used in developinc sinilnr prograns

2 .   Snake Lake, Viisonsin USA
    The water removal /re fill technique has been carried out
at Snake Lake, Wisconsin.  In the. summer of 1970 about tnree
lake volumes of water were pumped and deposited on land
above the lake.  Nutrient-poor water from contiguous cjrouna
water aquifers and precipitation were allowed to replace tne
removed water.  In the fall phosphorus concentration was
half that of the previous years.  The lake nutrients and
other effects continue to be monitored.
    Additional dilution and dispersion experiments have been
proposed at Moses Lake  (71) and Vancouver Lake  (72),
Washington, and at Lake Pled, Yugoslavia  (73).
Covering of Sediments

    Covering of bottom sediments with sheeting material
 (plastic, rubber, etc.) or particulate material  (clay, tly
ash, etc.) can theoretically perform tvo  functions in
restoring eutrophic lakes.  First it can  prevent the
exchange of nutrients from the  sediments  to  the overlying

water, and second,  it can prevent or retard the

establishment of rooted aquatic plants.
    One problem encountered when covering sediments is  the

ballooning of sheeting, or rupturing the seal of particulate

material, when gas is produced in the underlying seuiments.

    For particulate material, the small sizes whicn have

relatively low effective specific gravity (i.e. clays,  tly

ash)  appear to be best suited for sediment covering.

Materials of larger size  (sand and silts) tend to sink  below

flocculant sediments.  Sands and silts, however, can oe

effective in areas where the sediments are more

consolidated.  Materials such as Kaolinite- arid fly asii,

which have a high water soluble lime content, have tne  aciaea

advantage that they will remove phosphate from the water and

carry it to the bottom in a relatively insoluble torrn.

    Covering of sediment to improve lake conditions has been

done at Marion Millpond, Wisconsin (70).  About 12.1

hectares (29.9 acres) of this 44.5 hectare (69.9 acres) .Lane

were physically treated by (a)  sand blanketing, (b)  scraping

of overburden to a sand substrate, and (c)  covering tne


sediments with black plastic sheeting anchored with Sana and

    The University of Notre Dame is evaluating fly ash to
cover and prevent sediment nutrients from entering the
overlying waters  (7U).  This appears to have promise not
only as a barrier between sediirent and water but also as a
material to remove phosphate from the lake during

    The possible consequences resulting from the application
of fly ash to lakes as a sediment covering agent onould be
thoroughly evaluated prior to application.  Fly ash
frequently contains numerous impurities including several
heavy metals, phosphorus, boron, radioactive wastes ana many
others.  The damage resulting frcm "treatment" with fly ash
could conceivably offset any benefits.
Artificial Destratification and Hypolimnetic Aeration

    Possible techniques for altering the water quality in
eutrophic lakes include artificial destratification ana
hypolimnetic aeration.  These methods are of particular


value in improving the water quality of lakes in whicn trie

hypolimnion is void of dissolved oxygen and thus

uninhabitable by aerobic organisms.  The effective actions

of both of these processes are to increase oxyqen

concentrations in the water, promote the oxidation of

reduced organic and inorganic substances and enhance biotic

distribution.  It must be emphasized, however, that tnese

techniques are palliative in nature, i.e., they will not, in

themselves, restore a lake.  Aeration techniques generally

treat the symptoms of over fertilization rather than tne

source.  Permanent restoration will be accomplished only be

removing or significantly reducing the primary nutrient

inputs to a lake.  Following such a reduction aeration

methods may be effective in increasing the rate or  recovery.

    Artificial destratification of a thermally stratitied

lake is most often accomplished by injecting air into tne

water at the deepest point.  As the bubbles rise to tne

surface vertical water currents are generated.  The colder

and denser bottom water mixes with the warmer surface water,

sinks to a level of equal density and spreads out

horizontally.  Oxygen is added to the water directly from

the compressed air as well as by contact with the atmosphere

and by photosynthesis of aquatic plants.  As the mixing


process continues, complete circulation is achieved and the

lake approaches an isothermal condition in which the water

temperature and dissolved oxygen level are approximately

equal from top to bottom.  Likewise, with elimination o±

distinct epilimnion, metalimnion and hypolimnion zones, the

whole watermass becomes inhabitable by the biota.  The time

required to reach this condition depends on the time of

year, size of the lake, degree of stratification and method

of air injection.

    Artificial destratification may also be accomplished by

utilizing a mechanical pump to move the bottom water to the

surface.  Although this technique does effect complete

mixing, it does not afford the advantage of oxygenation

directly from the air bubbles produced by air diffusion


    In contrast to artificial destratitication, the process

of hypolimnetic aeration does not disrupt the thermal

stratification of a lake.  The aerator consists or a large

diameter pipe which extends from the lake bottom to aoove

Air is released throuqh a diffusor near the bottom of trie

pipe.  As air rises in the pipe, water is drawn in tnrougn

the bottom ports.  Oxygen diffusion occurs as the water

rises to the surface with the air bubbles.  At the top oi

the pipe the air escapes into the atmosphere.  The water

sinks to the outlet port where it flows back into the

hypolimnion.  After the establishment of a hydraulic head in

the pipe, water flows directly from the inlet to the outlet

ports without rising to the surface.  Hypolimnetic water,

therefore, is aerated but not significantly heatea or mixed

with epilimnion or metaliirnion water.  Thus, the aissolved

oxygen level of the bottom waters is increased, but tne

integrity of the thermal strata is maintained, witn tne warm

water of the epilimnion overlying the cold water of tne

    The benefits of artificial destratification and

hypolimnetic aeration are most pronounced on eutrophic lakes

which undergo oxygen depletion in the hypolimnion, in

contrast to oligotrophic lakes which never become oxygen


deficient.  The changes in water quality which are induced

by these techniques include the following:

    1.   Due to the increased oxygen levels in the

hypolimnion, there is a reduction  in the anaerobic release

of nutrients from bottom sediments  (75).  This results in a

general decrease in productivity of the body of water.

    Also due to higher hy^olimnetic oxygen levels, oxiaation

of reduced organic and inorganic iraterials occurs in trie

water  (77).  This is particularly  important when the lake

serves as a raw water supply.  In  such cases, the need for

specialized water treatment processes to remove taste and

odor carrying materials such as iron and manganese is


    2.   The range of benthic populations is extended into

areas which were once anaerobic  (75).  An increase in the

number of fish and a shift to more favorable species could

result due to the greater availability of food organisms

 (75, 78).

    3.   Favorable changes in algal populations occur with a

decrease in undesirable blue-green species and an increase


in green algae species  (79).  This is a result of the

continued movement ot the algae from the aphotic to tne

euphotic zones (76) , the lowering of water temperature ot

the epilimnion, and the modificaiton of the nutrient

availability.  The decrease in blue-green algae could result

in a reduction in raw water taste and odor problems.  Tnere

also appears to be a reduction in actinomycete population

which could improve water taste (80).

    U.   Artificial destratification increases the neat

budget of a lake by inducing complete circulation (75) .  An

increased rate of productivity results.  This is of

particular importance in oligotrcphic bodies of water.

    5.   Artificial destratification reduces evaporation

rates by slightly reducing surface temperatures during the

summer (81).  In areas such as the southwest United States

where water is in short supply and is expensive, significant

savings can be achieved by reducing the rate of evaporation.


    6.   Artificial dcstratitication often results in
increased water clarity  (75).  This appears to be associated
with reduced alqal populations,

    7.   Winter fish kills may te prevented by artificial
destratification due to  the maintenance of high oxygen
levels under ice  (82).


    Problem areas associated with these two methods may
include the following phenomena:

    1.   The increased heat budget produced by artificial
destratification may be  deleterious to cold water fishes,
particularly in shallow  lakes in which the temperature is
increased excessively at all depths  (81).  Also, warmer lake
waters may reduce a lake's usefulness as a source or cooling
water for industry and,  if the lake is a public water
supply, the attractiveness of drinking water derived from
the destratified  lake  (77).

    2.   Both artificial destratification and hypolimnetic
aeration may increase water turbidity due to the


resuspension of bottom sediments  (80).  This is often *

temporary problem, however, and may be resolved i / continued

mixing or a change in the location of aerators.

    3.   In most investigations these methods have ^roauced

a reduction in blue-green algae populations with a

subsequent increase in green algae such that total

productivity remains about the same (7f, ft 3) .  In otaer

instances there has been no observable effect on i>lue-green

algae populations with the result that problems associated

with these organisms have remained (8U) .

    4.   If oxygeriation is insufficient to increase ti.e

hypolimnetic oxygen concentration rarialy enough during

destratif ication, fish kills may occur (85).
    5.   The artificial destratif icaticn procedure

induce foaming, an aesthetically undesirable \. hencrrenon


    6.   The oxyaen demand of resuspended anaerobic mud may

result in a decrease in oxygen concentrations to tne extent

that fish kills occur  (77).  Ihis is particularly true of

small, very eufcrophic lakes.

    The costs of applying artiticial destratification
techniques depend on such considerations as systems design,
length of operation, power cost, degree of stratification
and oxygen deficit in the lake  to fce destratiried.  Tne
findings of a survey of water-utility managers who nave
applied these techniques in an  effort to improve or maintain
the water quality of impounded  water supplies reveal tnat
although costs vary, certain generalities may be maae  (66).
Tt was found, for example, that both the initial cost per
unit volume and the operating cost per unit volume declined
as the volume of the reservoir  increased.  No clear trend
emerged with regard to the costs associated with the type of
equipment  (homemade or commercial) and the operating
schedule used  (continuous, continuous all summer, or
intermittant).  Tt should be noted that 89 percent or the
,respondents utilized aeration devices and only <* percent
used mechanical pumps.  Other less widely used techniques
were employed by the remaining  7 percent The majority ot the
operators  (83%) used electrical power.  One third of the
respondents employed continuous operation, one third
continuous during the summer and one third intermittant
operation.  The concensus costs of all the survey

respondents arc nresented  in  Tables  5  and 6.   These data

conline all types of eouipr.ent  and. operation.

                           Table 5

               Initial  Costs  Per Unit  ^nlure
                 (Purchase  and Installation)

    I laxirur                   'lean                 I'in irun
 f>16.00/1000 r3           $3.54/1000  r3         $0.°4/1000 r3
($60.50/nil gal)        ($13.40/ril  qal)        ($0.15/nil gal)

   l.GC/n3                $0.003/m3              $0.0054/n3
 ($0.051/1000 gal)        ($.013/1000 aal)

$159.70/ha-r             $35.59/ha-r             $0.41/!ia-p
($19.70/acre-ft)         ($4.39/acre-ft)        ($0.05/acre-ft)
          Operatinn  Co.^ts  Per Unit  T7olur:.e anc riirr
                           and :iainter.arcr)
    ! lax irun                   ."car
  S3.T.7/1000 r.3/yr      SO.77/1000  n3/yr
 ($13.90/ril aal/yr)    ($2.90/ril  nal/yr)       (.^0.01/nil qal/yr)

 ($0.014/1000  qal/yr)  ($0.003/1000 qal/yr)

 $37.4G/ha-r,/"r         $7.C2/ha-r/yr           $0.02/ha-r/yr
 ($4.C2/acre-ft/yr)    ($0.94/acre-ft/yr)       ($0.003/acre-ft/yr)


    These costs represent the actual costs incurred in-

applications of aeration devices.  It should be noted,

however, that cost estimates for future applications must be

generated on a case-by-case basis.  It will be difficult to

determine precise cost estimates, however, as there remains

a lack of information on the exact amount of mixing needed

to improve water quality in a qiven circumstance ana on now

mixing can be maximized with a given power input, thereby

minimizing cost so the the highest benefit/cost ratio can be

obtained (86).
Case Studies

1.  El Capitan Reservoir, California, USA (78, 81, 87)

    The El Capitan Reservoir is an impoundment on the San

Diego River.  This body of water typically experiences one

annual period of thermal stratification usually lasting from

March or April to November or December.  The reservoir was

continuously aerated by diffuse air injection during tne

summers of 1966 and 1967.  The chemistry and biology ot tne

lake were investigated during these periods as weii as

during the summers of 19 6U and 1967 when normal


stratification was allowed to occur.  During the course of

the study the depth of the lake rose from 24.8 m in 1964 to

33.3 m in 1967 and the total volume increased from 1,136 na-

m (9,200 acre-ft) in  1964 to 2,698 ha-m  (21,845 acre-ft) in


    The total cost of equipment, materials and labor to

install the system was approximately $6,010.  At 6 percent

interest, the 10-year amortization cost will be $82!>

annually.  With continuous operation on a 6-month basis eacn

year, total power consumption was approximately $1,674.

Monthly electrical service charges totaled an additional

$177.  Including the amortization and power costs, plus an

estimated $250 per year for maintenance and repair, tne

estimated annual cost of operating the destratification

system on El Capitan Reservoir was $2,926.

    Changes in the chemistry and biology of the lake were

quite evident following artificial destratification.   The

lake became isothermal from top tc bottom.  The heat budget

increased.  For example, the maximum heat content ot  the

lake in 1966 during destratification was 25,116.0 cal/m3

above 0.0°C as compared with the maximum of 22,546.4 cax/m3


above 0.0°C observed during the thermal stratified condition
of 1967.

    During destratification dissolved oxygen was distributed
to all depths and was essentially uniform from toy to
bottom.  It was observed, however, that the surface oxygen
concentration of about 5 mg/1 found during 1965 was
significantly lower than the 8 mq/1 which occurred in 19t»4
under stratified conditions.  This indicates that an
accelerated oxidation rate may have occurred during forced

    Phosphorus concentrations in  the hypolimnion decreased
from as high as  1.4 mg/1 during stratified conditons to 0.1
-  0.2 mg/1 durinq destratif ication.  During clestratiti cation
the phosphorus level was uniform  from top to bottom.

    Prior to destratification the combined concentrations of
iron and manganese were 0.65 and  1.U6 mg/1 at 7 and 17
meters  respectively.  These values exceed the level of 0.3
mg/1 recommended for potable water by the U.S. Puoiic Healtn
Service.  Following destratif: ication, the combined
concentrations of iron and manganese were below 0.3 mg/1 at
all depths.


    Benthic organisms such as midge larvae and pupae,

oligochaete worms, nematode worms and freshwater clams; were

absent from the hypolimnion prior to destratification.

During destratification these organisms invaded tne ueepest

part of the lake and increased in total numbers.

Zooplankton populations were also affected by

destratification.  For example, over 85 percent or the

zooplankton were found below 10 meters on June 17, 19ob,

under destratified conditions, whereas less than 10 percent.

were observed below this depth the previous year una^r

stratified conditions.  Destratification, therefore,  allowed

a greater depth distribution of these organisms,

    Although no data have been reported on the eftect of

destratification on algal populations in El Capitan

Reservoir, the results presented indicate that artificial

destratification did produce a significant improvement in

water quality in this body of water.
2.  Wahnbach Reservoir, Germany (77)

    Wahnbach Reservoir is used as a water supply ana as a

source of industrial cooling water.  It contains 4,168 ha-m


(33,7UO acre-ft), has a maximum depth of U2.9 m and an

average depth of 19.2 m.  The lake is rapidly becoming more

eutrophic due to the introduction of domestic sewage ana

agricultural runoff.  During periods of thermal

stratification, a complete lack of dissolved oxygen exists

in the hypolimnion.

    The reservoir was aerated by diffused air injection

during the summer of 196U.  Oxygen was maintained tnrouyhout

t-.he lake.  Unlike previous years, the oxygen content dia riot

decrease to below 30 percent saturation at the mud-water

interface at any time during 196U.  Compared to previous

years without aeration when manganese concentrations of uy

to 20 mg/1 were observed, aeration generally reducaa tne

concentration of manganese throughout the lake to less than

1.0 mg/1.  Some increase  in dissolved phosphorus levels in

the surface water was evident during aeration although this

had occurred previously when there was no aeration.  No

increase in production occurred during the destratified

period.  A decrease in the population of the blue-green

algae Qscillatoria sp. was observed, however.

    Although improvements in many aspects of the water

quality of Wahnbach Reservoir were produced by artificial


destratification, a detrimental effect occurred.  Increases

in water temperatures rendered the water unsuitable for

drinkinq and for industrial coolinq water purposes.  To
overcome this disadvantaqe, a system of hypolimnetic

aeration was employed to raise oxyqen levels without

increasinq water temperature.

    Hypolimnetic aeration of the reservoir was employed from

July to November, 19*6.  Thermal stratification was

maintained and the lake became aerobic throuqhout.

Manqanese concentrations tell to below 0.1 mq/1.  Pnospnorus

concentrations declined from 80 uq/1 prior to aeration to 20

ug/1 after aeration.   Hypolimnetic aeration, therefore,

produced water quality chanqes similar to artificial

destratification without adversely affectinq the temperature

reqime of the lake.

    The installation cost for the diffused air injection

apparatus was $3,750.   This includes $2,500 for tne purcaase

of a 36.5-kw compressor and $1,250 for the air distrioution

pipe.  The operational costs, primarily electrical  power

costs, for approximately 5 months of continual aeration were

$2,250 in 196U.  The annual operatinq cost was $0.15/1000 nr


{$.57/mil gal) of drinking water withdrawn from tne

reservoir -   1U.8 million m3/yr  (3,900/mil gal/yr).

    The hypolimnetic aeration equipment required a Higher

capital investment - $8,250.  In addition, $U,500 was

required for  a raft with an overhead crane used for

assembling the apparatus.  The compressors and plastic pipe

cost $3,750.  Total installation cost, therefore, e4ualea

$16,500.  The operational costs  for hypolimnetic deration

were only slightly less than for artificial

3.  Hemlock Lake, Cheboygan County, Michigan, USA  (76)

    Hemlock Lake is a  1.8 hectare irarl lake having a maximum

depth of  18.6 meters.  Hypolimnetic aeration was applied to

the lake  continuously  frcir June  1U to September 7, 1970.

    Aeration increased hypolimnetic oxygen levels trom zero

to over 11 mg/1.  The  temperature of the hypolimnetic water

increased more than 12 C above its normal level.  Tnis was

due in part to heat conduction through the aeration tower

and can be minimized by using insulation.


    After an initial increase in phytoplankton cell numbers

immediately after initiating aeration (attributed to tne

leakage of nutrient rich hypolimnetic water through tne

tower into the epilimnion), the standing crop decreased from

over 30,000 cells/ml to less than 500 cells/ml.

Concomitantly, Secchi disk measurements increased to over 9

meters, the deepest ever recorded for Hemlock Lake.

Aeration did not appear to affect the periphyton standing

crop.  Following aeration,  zooplankton inhabited the lower

lake waters and their numbers increased until preaation

stress by fish caused zooplankton numbers to decline.   Tue

total number of zoobenthos was increased by aeration

although the biomass remained the same.   The zoobentnos were

able to inhabit the deep water during aeration as were

rainbow trout.

    The results of this study indicate that hypolimnetic

aeration may be an effective method of alleviating the

eutrophic condition of a body of water.


4.  Boltz and Falmouth Lakes, Kentucky, USA (79, «d, 89)

    Boltz Lake and Falmouth Lake were artificially

destratified by diffused air injection during the summer of

1966.  Bullock Pen Lake, also in Kentucky, was not

destratified and acted as a control.  The morphological

characteristics of the lakes are given in Table 7.
                          Table 7
       Morphological Characteristics of Bullock Pen,
                  Boltz and Falmouth Lakes



    Intermittant aeration was used.  Boltz Lake was

destratified four times during the period June to September

and Falmouth Lake five times.


    In both lakes, the temperature of the bottom water

increased during the aeration periods and decreased or

leveled off between aeration periods.  The net effect of

intermittant aeration was to increase the bottom

temperatures by over 20 C during the course of the summer.

Likewise, hypolimnetic oxygen concentrations increased

during the mixing process and decreased between periods ot

artificial destratification.  The net effect througn the

summer was to increase the oxygen levels of the deeper water

and decrease the concentrations of reduced materials such as

iron and manganese.

    The sum of the ammonia and nitrate nitrogen

concentrations at the 1.5 m depth in the unmixed laxe

remained at about 0.2 - 0.3 mg/1 throughout 1966.   boltz

Lake exhibited concentrations in about the same range at the

1.5 m depth except for the last mixing period.   Duriny tnis

period the concentration of NH3-N plus NO3-N increased to

between 1.0 and 1.5 mg/1 after which it leveled ott ana

subsequently declined to torirer levels.  Smaller increases

in the concentration of ammonia and nitrate nitrogen

occurred during two of the mixinq periods in Falmouth Lake.

In each case,  the concentration declined after aeration



    The soluble phosphorus concentration at the 1.5 m depth
in the unmixed lake varied between 20 and 50 ug/1 in 1966.
Concentrations at the  1.5 m depth in Boltz Lake, however,
exhibited an increase  from 5-10 ug/1 in May to
approximately 100 ug/1 in September.  Falmouth Lake
exhibited a net decrease in phosphorus concentration at the
1.5 m level from May to September although the
concentrations increased during most of the mixing periods.

    The surface plankton counts in the unmixed lake were
between 1,000 and 3,000 per ml from June to mid-September.
Boltz Lake exhibited declines in plankton counts during
three of the four mixing periods and Falmouth Lake during
two of the five.  When these declines took place they
occurred at all depths.  In most cases, an increase in
plankton counts took place after mixing stopped.  These
increases were not of  "bloom" proportions, however, and
despite periodic increases in nitrogen and phosphorus caused
by mixing, excessive algal growth never occurred during any
of the artificial destratification experiments,  wnereas the
unmixed lake exhibited the predominance of blue-green algae
characteristic of the  geographical area, a shift to green
algae occurred during  several of the mixing periods in both
test lakes.


    It r-ay be concluded  fror  this  :;tudy that artificial

dcstratification  elirinatcs them a 1 stratification, adds

dissolved oxyrren  to  th<;  vatcr,  causr- oMidrti^r. o^ reduced

substances arc"1  can produce-  a  shift in nlral ^r^dor

fron blue—rreen to green species.   The results also inc'icato

that artificial destratification should be initiated in the

spring or early sunrier and  should  be contiruod, at least

periodically, throughout tho  sunrrr for l.o^t .117 rovn ort of

v/atf-r c;uality.

5.  Parvin Lake,  Colorado,  VE?  (PO)

    Parvin Lal;e van  artificially dostrati fier' fror Hover] rr,

19GP, to iJecer)  rr, 1P7P, in an  e^^ort to irv.-rovr t:ie

\ inter hyj olirnrtic  oxyg^r.  deficit and surfer Muo-c

algae 1 looms.   Continuous air diffusion was erployed.

Parvin LaJic has a surface area  of  19 ].a, r-axirtun depth of 10

r. and a rcan dej'th of  4.4 r.  It is located at an rlevatior

of 2,500 n in the RocV.y  .Mountains  of Colorado.

    Total phytoplanhton  abundance  decreased ir Parvin Lav«

during artificial destratification,  but th.p decrease x;as not

uniforn among all phyla,  freen algae declined during

destratification.  This  may have been due to the coldor than


normal winter water temperatures and warmer than normal

summer temperatures.  Planktonic diatoms decreased in

population size durinq the winter when they normally

dominate.  Several tlue-qreen algal species increased in

number durinq the summer over previous, untreated years,

namely Anabaena f_los-aguae, Aphanizomenon flos-aquae and

nomphosphaeria lacustris.

    These results indicate that complete understanding of

the response of eutrophic lakes tc artificial

destratification is lackinq.  whereas other investigators

observed decreases in blue-green alqal populations durinq

mixinq periods, this study tound that several of these

species increased in number.  Because of this difference in

observed response, it is evident that the potential eftects

of artificial destratification should be evaluated on a

case-by-case basis.


    Water level manipulation exists as a potential mechanism

for enhancing the quality ot certain lakes and reservoirs.

Lake drawdown has been investigated as a control measure for

submersed rooted aquatic vegetation, as a means to retard


nutrient release  from the sediment nutrient pool, and as  a

mechanism for  lake deepening through sediment consolidation.

    Observations  from natural drawdown and subsequent

exposure ot the bottom sediments have indicated irar*ed

improvement in the water quality of two Florida lakes.

Before drawdown the lakes produced heavy algal crops.  Alter

drawdown and sediment drying, rooted aquatic plants replaced

the algal community making the lakes more amenable to yame


    Experiments, with sediments froir Lake Apopka, Floriaa, in

1967-68 showed that when the sediirents were dried and

reflooded a balance of aquatic weed and shoreline (emergent)

vegetation grew (91).  Further, the sediments oxidized ana

would not resuspend upon flooding.  It was concluded trom

these studies that drawdown for 6 to 8 weeks during the dry

season should result in a suitable aquatic weed crop.

    Drawdown has been carried out in three Wisconsin lakes:

Marion Millpond, Snake Lake  (70)  and Jyme Lake (92).  At

Marion Millpond many manipulations besides sediment exposure

were made:  bottom stumps and logs were removed; some

sediment was removed and sand and plastic were placed i


some of the littoral areas.  Therefore, the effects of

sediment drying were masked by these other rehabilitation


    At Snake Lake the primary objective was to restore tne

lake by pumping nutrient-rich water trom the lake and

allowing it to be replaced with nutrient-poor qroundwater.

Tn lowering the water level by 3.35 meters the seuiments

were exposed to air which resulted in extensive compaction

and likely chemical alterations by oxidation.  The

phosphorus concentration decreased by half after tne lake

refilled but this likely was mainly attributable to tne

dilution water.
    Jyme Lake is a 0.45 hectare, 3,7 m deep acid-boj s

lake in Oneida County, Wisconsin.  Beginning in October

water was pumped interirittantly for a 10-day period to a

nearby low-lying cattail marsh in an effort to drain tne

lake to allow investigation of sediment consolidation as a

lake deepening technique.  Attempts to completely drain tne

lake were unsuccessful due to the flow of low-solids mud ana

peat on the lake bottom and from teneath the vegetative mat

of the bog, and a subsequent subsidence of the level oi tne

bog.  The wood fragments in the mud clogged the pump

impeller forcing termination of the project prior to winter
freeze-up.  The Jyme Lake experience indicates that although
lake drainage and sediment consolidation is a potential
physical deepening technique,  to be effective the laxe must
be completely drained and the water table must be maintained
below the surface of the lake sediment surface.  Because ot
possible pumping problems and slumping difficulties
encountered during the draining of bog lakes, this technique
may be more applicable to lakes with a greater percentage ot
inorganic sedimentary fill.

    In the Tennessee Valley Authority lakes it was observed
that lowering the water level  1.83 meters for a period of 21
to 25 days during the winter provided a 90 percent reduction
in the acreage infected with Mvriophvllum s£icatum (93).

    Studies on drained marsh areas have shown that water
removed during the drainage period would carry with it much
of its total burden of nutrients (9U).   It was concluded
that frequent drainage could heavily deplete the fertility
of marsh environments.

Harvesting Nuisance Organisns
    Algal harvest is particularly difficult because trie

algae are normally in dilute suspensions and of small

physical size.  For these reasons most attempts at algal

harvest have been conducted on lagoon waste water effluents

which have a relatively high concentration of algal cells.

Even at these concentrations Oswald and Golueke  (9b)

indicate that in order to obtain a usable, economically

feasible end product, the following three steps are

necessary:  1) initial concentration of the algal

suspension, 2) dewatering and concentrating the resulting

slurry, and 3) drying the dewatered algae for storage and


    Algal harvest may be accomplished by centrifuging,

filtering, coagulation, microstraining, sonic vibration,

flotation, and changing of ionic characteristics ot t.he

algae with ion exchange resins  (96).  Coagulation of alyae

with aluminum sulfate, lime, and alum have been used in

combination with the above methods  (97).


    A high grade end  product is most cheaply obtained  by

centrifugation, whereas a  lower grade product is most

cheaply obtained by combining centrifugation with  tne

coagulation or flocculation process  (96).  According to 1967

estimates one metric  ton of dry algae  (low grade)  could be

produced at a cost of  $66  to $88  ($60 to $80/ton).  No firm

market value for the  finished product could be establisned

in 1968, but it was estimated to be worth about $95 per

metric ton ($86/ton)  with  an additional $10.00 per 378b m3

(mil. gal.) of high guality process water as a frinye

benefit.  Products of  the  process would then yield axi income

of nearly $105 per metric  ton of dry algae at a production

cost of $66 to $88 for a net protit of $17 to $39  per metric

ton of dry algae.  According to Levin and Barnes (^8)  a

similar quality low grade  product iray be produced by tne

froth flotation process for approximately $52 per metric ton

($U7 per ton).  Assuming the same market value for the end

product this method might  realize a net profit of nearly j>55

per metric ton ($50 per ton).  If these figures represent

real numbers a municipality or industry might be able to

economize significantly on wastewater treatment by narvest

of algae.


    Algal harvesting studies which utilized the eftluent
from wastewater lagoons have demonstrated that nearly 90
percent of the nitrogen can be removed in the form of algal
protein  (99, 100).  One field study demonstrated 50 to 70
percent inorganic nitrogen removal and 19 to 68 percent
phosphorus removal from wastewater with algal harvest (101).
Soluble phosphate has been reduced by 90 percent using nigh
rate algal culture techniques  (102).

    Under highly favorable climatic conditions up to 70
percent of the nitrogen and 50 percent of the phosphates
have been removed from wastewater by algal action alone
 (103).  In laboratory cultures under controlled conditions
50 percent of the total inorganic nitrogen was removed by
algae in one day and 95 percent in four days  (104).

    It has been estimated  (95) that .6 million hectares  (1.5
million acres) of land devoted to algal culture would
satisfy the oxygen demand of all liguid-borne wastes in
 1967.  The need by the year 1990 is projected to be aDOut
2.42 million hectares  (6 million acres).  The algae
recovered would meet approximately one-quarter of the
protein needs of the nation's livestock industry, and since
the 0. S. has about 121.4 million hectares  (300 million


acres) devoted to protein production, the savings in water

resources normally used to produce protein could amount to

        11  3
2.5 x 10  m°  (200 million acre-feet) each year  (96).  This

technique should be evaluated with regard to efficient land

use practices.

    Data regarding algal harvest from lakes are severely

lacking, probably owing to the relatively sparse algal

oopulations found in lakes.  Levin and Barnes (98)  noted

that the efficiency of harvest was inversely proportional to

culture density.  Another probable reason for lack of lake

data is that algal bloom populations usually consist or

blue-green algae for which there is a limited marKet.  Green

algae usually associated with the nutrient-rich wastewater

lagoons, on the other hand, are a potentially valuable

source of protein.

    Despite the apparent success of some methods ot algal

harvest as a measure of nutrient removal, many problem areas

still remain.   It appears now that there is little nope ot

developing an in .situ lake-oriented method of harvesting

algae that would be economically feasible.


Macrophytes and Higher Organisms

    Excessive macrophyte growths due to nutrient im£>

designed to physically uproot and destroy these plants

(107), but both  types of  plants have economic value  it

controlled; pondweed as the  major duck food plant  in tae  U.

S.  (11U), and milfoil as  a feed supplement  (115,  1 1fa).

    Development  of specialized cutting machines has

progressed to the point where relatively efficient cutting

can be accomplished, but  the major expense comes in

collecting the cut debris and removing it from the water,

Various devices  for reduction of weight and volume ot tne

crop have been designed,  such as screw presses (117,  11b,

110), high pressure crusher-rollers (111, 117), brusn

chippers and crushers  (106), as well as assorted efficiency

improving pretreatments (108, 117, 110, 111).

    From a health related standpoint,  especially with

reference to food production, Abou-El-Fadl et al  (119)

observed no infectious stages ot helminths (schistosomes)  in

harvested water  hyacinth  (this is a severe problem in

temperate, tropical, and subtropical countries),  but noted

that the crop must be composted before use as an organic



    Various estimates ot nutrient removal efficiency nave

been made, but there is widespread disagreement.  Lee

is of the opinion t.hat harvesting, in general, does not ma*e

significant inroads in the nutrient balance of the lake,

although it does remove certain aincurits ot nitrogen ana

phosphorus.  Rogers  (121), however, points out that 1

hectare of water hyacinth could absorb in 6 months tne

annual nitrogen and phosphorus wastes of about 550 people.

Livermore and Wunderlich  (106), cite work  (106, V2.2) that

indicates that the harvest of six species of plants in La*e

Mendota, and milfoil harvest in Caddo Lake, could yield up

to 202 kg/hectare/year  (180 Ib/acre/yr) of nitrogen and 31.8

kg/hectare/year  (28 Ib/acre/yr) of phosphorus, which would

represent substantial nutrient removal in many lakes.  Youat

and Grossman  (107) indicate that primary production is

reduced by harvesting, but only if the intact plants are

removed from the area but, "if tco much vegetation is

removed, the availability of these pollutants to otfter

organisms  (such as algae) is increased....the problem is

resolved by managing a population on a sustained yield

basis."  See also  (123).

    Steward (124) indicates that.emergent macrophytes are

substantially more productive  (in terms of dry weight) than


submerged rooted species, and cites the work  ot  tne

County Pollution Control Department, Orlando, Florida,  wnere

the nutrient balance of a small eutrophic  lake has been

successfully restored by qrowing water hyacinths in a  fenced

area in the center of the lake.  Atter one year the lax.e  was

clear and supporting fish.

    In studies ot two full scale treatment plants usea  iu

processing citrus pulp waste  (113), the ot  water

hyacinth in the removal of nutrients in aerated lagoons ana

oxidation ponds has been evaluated.  It was determineu  tnat

a minimum of 5 days retention time was requirec to attain

substantial nutrient removal, and the hyacinths were moat:

efficient at D.O. concentrations below 0.5 mg/1, ana rurtrier

that the microbiota attached to the roots of the nyaciatii

were responsible for substantial reduction of EOD (70

percent)  and COD (U7 percent) .  A considerable amount of

nutrients (contained in the presswater)  were releasea during

squeezing in a drying process, i.e., . U hectare  (1 acre) ot

hyacinths at 336 metric ton/hectare (150 ton/acre), would

yield 128.7 m^ (3U,000 gal)  of pressed liquor containing oJ

mg/1 PO4~P and 335 mg/1 total N).  Analysis showcu an animal

feed value of the processed hyacinth comparable to aitulta



    Steward  (12U) further calculates that water hyacintn has

the highest nutrient reduction potential of eight species

compared.  Taylor, Bates, and Robbins  (125) assayed the

protein content of water hyacinth finding that, "altnough

the quantity of the protein extracted was low, it appeared

to be of good nutritional quality as evidenced by tne

proportions of essential aniino acids,"  The crude protein

concentrate  (33.6% recovery by alkali) ranged from a summer

low of 4.7 percent  (dry weight) tc 5.8 percent in winter,to

9.2 percent in the spring.

    There has been considerable work done in Germany over

the past 10 years with the bulrush, Scirpus lacustris L., as

a biological filter for use in pond reclamation and sewage

treatment  (126 -  128).  This rush, which has worldwide

natural distribution, can grow in an astonishing variety ot

situations,  including saline water and highly contaminated

freshwater.  Scirjous has been shown to have the aoility to

penetrate and break chemically precipitated hardpans in

holding ponds, allowing percolation to the ground water.

Before the introduction of the rush, the water stagnated.

Scirpus, by virtue of a root exudate termed a "phytondice",

is able to lyse  (kill) ccmmon sewage bacteria  (F;. coti,

Salmonellae, etc.) completely, rectify the pH of tne


entering sewage effluent to 7 t 0.5, and is capable of

removing large amounts ot organic and inorganic nutrients,

storing these nutrients in its "phyllosphrre" or leaf biaae

which is harvested periodically and utilized in a number of

ways, e.g. fuel, cattle feed roughaae, paperboard tioer.  in

pilot, plant operations, flow-through channels of dcirpus

have shown the ability to reduce PCC by 96 percent, orten to

less than 5 mg/1, phosphate by 50+ percent, and ajuuonia by

more than 99 percent  (22 mg/1 to 0.1 mg/1).  The process

improves the activated sludge process, is capable ot dU

percent reduction of total nitrogen, and its metabolism is

reduced by only UO percent under ice cover.  The aesigns are

suitable for small cities in the 20,000 to 40,000 population

range.  There are an increasing number of installations in

European countries, treating both domestic and industrial

effluents.  Steward (12U)  reports that an industrial

installation in Germany treats 5 Trillion cubic meters or

effluent per day by passage through 20 basins, 400 meters

long by 50 meters wide, planted with Scirpus.

    The other area of possible interest in nutrient removal

is that ot vegetation consumers, such as fish and shellfish.

Some research seems promising.  Greer and Ziebell (12^)

tested various fish and shellfish, and found the oriental


clam, Corbicula fluminea was most effective; at

concentrations ot 5.0, 10.0, and 15.0 mq/1 PO^ this system

can remove the PO- ion to below 0.30 mg/1 in 16 days or

less, yielding a clear effluent.  This process occurs partly

by sedimentation of psuedo-feces  (mucous bound undigested

pellets of algae) which are not resuspended.  X-ray

diffraction of sediments showed that PC^   had been

precipitated  in the form of hydroxyl-apatite.  They

concluded from studies with Tiiafia arid channel catrisn,

that where algal blooms could be controlled, removal of

nutrients via sport fishery could Le feasible  (algal blooms

generally result in massive fish kills).

    Corey et  al  (129) estimated that fish harvest, on a

sustained yield basis, would result in catches of  3,37 kg per

hectare  (300  Ib/acre) of water surface annually  (spore

fishing about 1/3 of  the total), which would represent

removal of about 7.8  kq of nitrogen and 0.67 kg of

phosphorus per hectare  (7 Ib N/acre and 0.6 Ib P/acre).

    There has been recent work in this country concerning

the use of Ctenopharygodon idella Val,, the white  amur or

grass carp, in controlling aquatic plants.  Claims have been

made that experiments in Arkansas have proven the  wnite amur


to be one of the best control agents for aquatic vegetation


    The state of Arkansas has released the white amur into a

number of waterways including some which will provide the

fish access to the Mississippi River Basin tributaries.  The

neighboring states of Texas and Missouri, however, have

banned the importation of the grass carp.

    Results from studies in Europe and Asia on the use of

this fish for weed control purposes are less encouraging

than those from the Arkansas studies.  Opuszynski (131)

reported that grass carp fry eat only animal food such as

zooplankton and Chironomidae larvae until they reacn a

weight of 1.8 g and a length of 36-U3 mm, and that the use

of macrophytes in their diets increases with increases in

size.  It was also reported that aniiral protein apparently

is a necessary addition to the diet for normal growth and

development of these fish (131).  When given a choice the

grass carp seemed to prefer macrophytes to algae.  According

to the Sport Fishing Institute Bulletin (132)  a recent

release from the Missouri Department of Conservation

provides preliminary evidence that the white amur prererred


amphipods over weeds when given a choice, and ate weeds only

in the tank deprived of amphipods.

    In summary, it appears that although the technical

methods for nutrient removal via harvesting are becoming

increasingly diverse and sophisticated, none is economically

feasible on self-supporting basis, although the costs appear

to be within reason for some situations.  Increased research

indicates that markets will develop for products created,by

these harvesting procedures.  There is substantial agreement

among authors that complete eradication of any species of

plant is undesirable, and management, especially by

biological means, is the ultimate goal.
Biological Control of Nuisance Organisms
    Hasler and Jones  (133) reported that dense growths ot

aguatic macrophytes were  inhibitory to the growth of

phytoplankton, both by direct cbmpetition for nutrients and

by shading.  On the other hand, Mulligan  (114) reported that

the technique  (used primarily by fish culturists) ot massive


fertilization stimulates blooms of green alqae, wnicu

submerqed macrophytes and prevent their ;3evelof merit.

Neither technique really solves anything, txcnanaing one

problem for another.
    Porter  (13U) reported on the effect ot grazing

Oa£>hnJLa and related zooplankton on natural phyto

populations in a mesotronhic kettle lake exper imentdi in

situ set up.  Selective reduction and siqniticant

suppression of numbers of phytoplankton are acconplisneu  by

    Mattox, Stewart, and Floyd  (135) reported the t-rt^

of virus particles in four genera of Ulotr ichalean

alqae  (viruses were previously unknown in eukaryotic al*jae) .

These  findings greatly increase the chances of develo^iuj

viral control procedures tor green alqae.  Saffermdn ana

Morris  (136) reported the first isolation of blue-green

alqal virus, which was found to he highly specific tot

several closely related blue-green alqae, Lyngbya.

Plectonema, and Phormidium, all of which are now classilied

by Drouet as Schizothrix calcicola.


    A significant amount of work has been done to develop

the virus as a control measure  (137, 138) in order to ta*e

advantage of the observed natural phenomenon of abrupt

massive die-ofts of blue-green algal blooms caused oy


    Broad-spectrum control of blue-green algae is also

exhibited by a bacterium, Mv_xobacter sp., as reported b>

Shilo  (138).  Bacteria and fungi apparently hold oome

promise as control agents, but much work, as with viruses,

remains to be done.

    Cappelman  (139) has developed a culture technique for

detached water hyacinth leaves that has allowed

demonstration of the pathogenicity of Alternaria s^., an

aquatic fungus, to the hyacinth.  The system holds

considerable promise for the demonstration of pathogenicity

of other organisms to the hyacinth, including viruses and

insects.  Sculthorpe  (140)  reports African work on the

sedge, Cyperus rotundus, noting that the planting of

Eucalyptus trees nearby reduces the growth of the sedges.

Also, work has been aone  in Italy on the control  or  tne

qrass Echinochloa crus-cjalli by the smut funqus,  Sorosporiuin
    The water hyacinth weevil, N^ochetina bruchi Hustacne,

showinq promise as a control aqent, has been introduced  to

numerous waterways in Florida by the Army Corps or  c,n-jineers

(1*11) after extensive research in South America.  Couison

(1U2) reportinq on the oriqinal research and future plans

for arthropod control aqerits, believes that signincaat

control of the hyacinth will result v,ith widespread

distribution.  One species cf mite, Crt.hoqalumna terebrantis

Wallwork, apparently introduced with the hyacinth, also

shows considerable control activity,  work is being

conducted in Uruquay on the crambine moth Acigona intuselia

(Walkor) , whose larvae are stem borers and althougn tney may

feed on sugar cane and rice, are only able to complete tneir

development on water hyacinth (Eichornia)  or Pontederi^  (a

closely related genus) .


    The nymph of an acridid  grasshopper, rornggs acjuatic_urr,
Bruner, has also shown considerable ability  to defoliate
water hyacinth.

    The developmental vvork on these arthropods is  i;ciavj aorie
at the ARS Laboratory in Albany, California, and woria-wide
under PLU80 funds.  Thrips,  previously  introduced,  nave not
successfully controlled the  hyacinth.
    Durinq the j.eri°^  1962  to  1967  work  was  conceatrateu  on
the flea beetle, Aaasicles, which is  rcost  specific  tor  tae
alligator weed, Alternan.thera
introduction  into  problem  areas  has  resulte.3  in  soiuewnat
successful control  (11U,  U2,  143).
    Baloch, Khan,  and  Gharii  (1^4)  reported  on the  isolation
and study of  four  insects  which  feed on  water milroii
 (Myrjoghyl lum spr. )  in Pakistan,  and their  possible use ao
control agents.  Frequent  fluctuations  in wator  levels
prevent the buildup  of large  enough  populations  or  taese
curculinoids  to  significantly  affect the irilfoil,  out it
such fluctuations  were prevented,  the introduction  ot tnese
insects, which damage  both seea-l earing  capacity ana


submerged parts of the plant, might result in effective

    Attempts have been made (114, 1UO, 145) to

advantage of the accidental introduction of the snail,

Marisa cornuarietis L. , for the biological control ot

aquatic weeds.  Although they are voracious consumers ot

aquatic weeds, they tend to disperse rather than uuiia up

dense populations, and have not keen numerous onougri to

significantly affect the standing crop.  One approacn

suggested is to confine them to small lakes, rather trian the

canals through which they have spread.

    Potamogeton sp. is the primary food plant of numerous

wild fowl, such as ducks, tut these biras apparently do not

have significant impact on aquatic weed populations.

    Only one mammal, the manatee, Trichechus manatus

latirost.ris, has been experimentally considered for control

purposes  (140, 146), but despite the fact that it consumes

tremendous quantities of aquatic weeds, it is a rare animal,

difficult to locate, catch, and transport, has not bred in

captivity or in freshwater, and simply does not exist in

large enouqji numbers to have a significant impact in terms

ot overall programs.  In individual experiments, aithouyn

expensive to conduct, the manatee has proven to be a very

efficient weed control agent.
Chemical Control of Nuisance Organises
    Fitzgerald  (1U7) has compiled an excellent review of

alqiciues, especially as they apply to lake management.

Although  the  most desired method of alleviating

eutrophication  is to restrict, nutrient input, many

situations have deteriorated to the pcint where direct

measures  must he taken  to control algal  growth, ana  one or

these  is  the  use of algicidal chemicals.

    Copper sulfate  is procably the most  widely usea  cnemical

against taste and odor  causing algae,  floating hlue-«jreen

algae  and filter clogging dlgae.  Over  11,000 metric tons ot

copper sulfate  are  used for this purpose per year  (1**7) at

concentrations  ranging  from less than  0.5 mg/1 to  more tnari

10 mg/1,  according  to the density ot algae and relative

water  quality.   Application methods vary from spraying from


a boat, or dragging a sack cf crystals behind a skitt,  to

aerial systems including helicopters.

    Test tube experiments with potassium permanganate have

shown it to be more toxic to certain algal species tnari

copper sulfate  (148),  Because potassium permanganate not

only kills algae, but also eliminates tastes and odors ana

removes iron and manganese sulfates, it may find usage in

the treatment of raw water reservoirs  (1U8).  Altnougn

organic mercurial algicides are potent and very ertective,

they are more hazardous in the long term to higher orjanisms

in the food chain, including man, and must be used with

extreme care.  Other algicides of some use are the resin

amines, triazine derivatives (such as simazine) , a mixture

of copper sulfate and silver nitrate, and ammonium

compounds.  Since the resin amines and copper are toxic to

fish, they must be used with caution.  Simazine, whicn has a

relatively low mammalian toxicity (11**),  controls plaaKtonic

and filamentous algae through inhibition  of the Hill

reaction.  Although it does not appear toxic to zooplaukton

and fish at recommended levels, it is taken up and

concentrated in fish tissues.   Mulligan (114)  reports tnat a

30:5 weight ratio of copper sulfate and silver nitrate nas

been Czechoslovakia.



    Timmons  (149) and Mulligan  (11U) have reviewed the means

of chemical control thoroughly.  The following herbicides

are the most widely utilized presently:  2, U-D and other

phenoxy compounds, dalapon  (2,  2 dichlcroproprionic acia),

diquat  (6, 7-dihydrodipyrido  (1, 2-a:2;1»-c) pyrozinedium

salts), paraquat  (1,  1'-dimethyl-U, U1- bipyridinium salts),

acrolein, xylene, dichlobenil  (2, 6-dichlorobenzonitriie),

and diuron  (3-(3,U-dichlorophenyl)-1,  1-dimethylurea) .

    Diquat, paraquat, and dalapon are  the most widely used

throughout Europe; but diuron  is used  almost exclusively tor

control of aquatic and bank weeds in the Netherlands,

3-amino-s-triazole  (amitrole)  and 3-amino-s-triazole +

ammonium thiocyanate  (amitrole-T) are  the most widely used

herbicides for aquatic and bank weeds  in Australia.  Tnese

latter compounds are  restricted or  banned in the U. 6.

(149).  Diquat,  paraquat and dalapon are safe for tish;

dalapon and diuron are safe for hurrans and  livestock.

    Mulligan  (114) indicates that esters of 2, U-D are much

more effective in killing aquatic plants than amides of

2, U-D, although there is much controversy  over 2, 4-D


residues accumulating in food organisms such as snellfisn.

2, U-D is reported to be photo-oxidizable and can oe broken

down by soil microorganisms in U-6 weeks to humic acids.

The butoxyethanol ester of 2, 4-D was used to control

Myriophyllum in the TVA Lakes in 1967 and Trapa natans

(water chestnut) in the Hudson and Mohawk Rivers.

Application of 2, 4-D usually results in temporary increases

in heterotrophic populations in the waters (114).

    Silvex is a non-selective, slow acting herbicide whicri

remains in the water up to 5 weeks.  Different formulations

have differing toxicities to food chain organisms, tne least

toxic of which is the potassium salt  (114)

    Fenac (2, 3, 6-trichlcrophenylacetic acid)  is a

persistent non-selective agent, reportedly of low rood cnain

toxicity (114).

    Endothal (3, 6 Endoxohexahydrcpthalic acid)  is used to

control submergent plants, sometimes in combination with

si1vex.  There is substantial concern over its unknown mode

of action and unpredictable toxicity to fish and other food

chain organisms.


    Diquat-bromide (1, 1-ethylene-2, 3-dipyridylium

dibromide) kills submerged plants on contact, has relatively

low toxicity, and can he removed from the water by

adsorption onto clay particles and subsequent sedimentation.

    In summary, the following observations should DC maae:

inadequate information exists concerning alqicicie ana

herbicide residues, breakdown rates, and long-term ettects

on other orqanisms; when plants are killed chemically,

oxygen levels quickly decline, often to levels toxic to

other organisms; plant-bound nutrients are released into trie

water; chemical agents offer only temporary, symptom

suppressing relief; treatments must be repeated frequently,

often semiannually or irore; chemical kills of macropnytes

are frequently followed by massive algal blooms; ana some

herbicides, such as endothal and silvex, may damage cro^s if

the water is subsequently used for irrigation.

    Contamination of lakes with various hazardous suDstances

is an everpresent threat.  Industrial accidents, spills

occurring during transport, intentional dumping or plain


carelessness may result in the release of a variety ot toxic

or noxious substances to the environment, with subsequent

transport to lakes and reservoirs.

    The initial effort in combating the problems ot lake

contamination with hazardous substances must be the

establishment of sound preventive measures througn the

cooperative efforts of the public, industry and government.

Prevention, in order to be effective, must be a requirement

of law, with appropriate controls and guidance imposed by

the various levels of government.  Secondly, industry must

meet its moral and legal coirmitments to society ana trie

environment by implementing appropriate precautionary

measures including proper inhouse plant design, adequate

safeguard mechanisms and procedures, and conscientious

management policies and operational practices.
Precautionary Measures

    Even with the best preventive methods in effect,

accidental and deliberate contamination of lakes witn

hazardous substances will occur.  A line of defense geared

tor an immediate response to spilled substances is essential


it major catastrophies are to be averted.  The essential
components of the response mechanism include capabilities
for tho containment or confinement of the spilled suustances
and removal or inplace treatment  (inactivation)  while the
material is concentrated in a localized area.

    Containment of spilled materials will not always be
possible, even though an efficient spill response system is
in operation.  A percentage of the spills will not be
detected or reported until after the spilled material nas
dispersed throughout the lake.  Also, continuous or
intermittent discharges of toxic cr other hazardous
materials over a period of time may cause lake-wide
contamination which precludes the use of containment

    In lakes where widespread contamination has occurred and
ecological damage has resulted, restoration programs wili
have to be initiated once the source of contamination nas
been curtailed.  If ecological damage has been severe and
the contaminating material is present in the lake in


sufficient quantities to  impede the natural recolonizatioa

of disturbed ecosystems or to hinder artificial j: ro^a^acion

efforts, a proceavjre tor  treating or removing the

contaminant must be implemented.

    Few in s^tu techniques for remcvinq or treating

hazardous materials in lakes have proved effective.  Jiace

many toxic substances such as heavy metals and pesticides

are readily sorbei onto particulate matter, incorporation oi

the material into the sediments and biota occurs very

rap>idly.  Consequently, such schemes as flushing, diiLitiou

and filtering of lake water do not necessarily remove tno

contaminant from the system, as the materials aro

available for recyclinq from the sediment an 1 Lioi


    Lambou (150) summarized existinq experiences ana

approaches which have been considered for deal inn wicri

mercury contamination in aquatic systems.  Since mercury is

one of the most hazardous of the heavy metals in tiie

environment, due to its tendency to be bioloqically

methylated, procedures which are effective in restoring

mercury contaminated lakes may possibly be applied to


contaminated by other toxic substances.  The following is

taken from Lambou  [150] :
         "The continuing supply of mercury from
    bottom sediments to the water and the slow
    rates of excretion of mercury fcy fish give
    little hope for quick improvement in levels of
    mercury residue in fish.  The Swedish
    experience confirms this.  In Sweden mercury
    in pike in most lakes has dropped little if at
    all since mercury bans became effective in
    early 1966.  These lakes where the fish
    residues have not dropped tend to be
    biologically poor and acid.  Only about three
    lakes apparently have had mercury levels in
    pike drop to a demonstrable extent.  Rivers
    have a better chance due to continual flushing

         "Jernelov  (1969) [151]  calculated that it
    would take from 10 to 100 years for the
    methylation process to remove the mercury from
    the bottom of lakes.  These calculations were
    based on the yield over a period lasting from
    1 week to 2 months of mono and dimethylmercury
    from bottom sediments taken from contaminated
    lakes and rivers and kept under natural
    conditions.  In Minamata Bay, Japan, once the
    cause of the pollution was determined and
    eliminated, mercury levels in shellfish
    dropped from 35 ppm to 10 ppm over a two year
    period and remained constant for at least a
    five year period  (Trukayama, 1966)  [152] .
    Rivers should have a better chance of being
    decontaminated because of the flushing action
    of currents moving sediments downstream.
    Mercury levels of salmon placed in cages below
    former sources of mercury in some Swedish
    rivers showed considerable improvement within
    3 years (Study Group on Mercury Hazards, 1970)

         "Swedish workers have considered the
    following approaches to the decontamination of

mercury contaminated waterways:   (1) introduce
oxygen-consuming materials to create
continuous anaerobic conditions in  the
sediments, thereby reducing methylation,  (2)
increase the pn of the sediments  to favor
dimethylation  and increased volatilization,
(3) cover the  sediments with fresh  finely
divided materials with hiqh adsorptive
affinity  (e.g., quartz and silicates),  (U)
cover the sediments with inorganic  inert
materials ot any type, i.e., bury them, and
(5) removo mercury-bearing sediments by
dredging or pumping  (Study Group on Mercury
Hazards, 1970)  [153].  The first two
approaches appear to be in practical, however
Sweden is evaluating the other approaches
(Study Group on Mercury Hazards,  1970)  [153],

     "Experiments have been conducted in
Sweien to evaluate covering sediments by
layers ot inorganic sediment of varying
thicknesses  (0-20 en), with and without
T.U.tJjLicijae  (olioochaote worms)  and Anodonta
(a bivalve)(Study Group on Mercury Hazards,
1970)  [153].  These studies have revealed that:
(1) in the absence of Tubi f icjldae,
methylmercury  accumulated in fish only when
the sediments  were uncovered, (2)  in the
presence of large populations of these worms,
fish accumulated methylmercury when the
covering layer was less than 2 cm, and  (3) in
the presence of An2il2Bi^» which stirs the
sediments, leakage of methylmercury occurred
it the covering layer was less than 9 cm.

     "Swedish  workers have conducted tests to
evaluate the ettectiveness ot ground silicate,
on the uptake  of mercury by fish from
sediments contaminated with metallic mercury,
ionic mercury, and phenylmercury  (Study Group
on Mercury Hazards, 1970)  [153].  These tests
have, revealed  that there was no reduction in
uptake when the pollutant was phenylmercury;
however, a decrease in uptake by a factor of
two occurred when inorganic mercury was the

         "The removal of mercury contaminated
    sediments by dredging appears to have some
    serious shortcomings.  For one thing, the cost
    to dredge any extensive area may be excessive.
    The dredging of a Finnish port increased the
    soluble mercury concentration in the water
    from a level of 0.5 to approximately 10 ug/1
    (Stephan, 1971)  [15U] .  This increase took
    •some weeks1 to reach a peak; however, it
    returned to backoround in a •few more weeks'
    (Stephan, 1971)  L15u] .  Swedish workers were
    of the opinion that by dredging there was a
    considerable risk of increasing the rate ot
    methylation of mercury in the sediments
    (Stephan, 1971)  [15U].  Measurements taken on
    sludges dredged from mercury sludge banks in
    Sweden indicated that while some 95 percent of
    the suspended solids can fce retained in the
    sludge, only 50-60 percent of the mercury will
    remain in the sludge, the remaining UO-U5
    percent being discharged with the supernatant
    (Stephan, 1971  [154],"

    Additional information on the effects of sand and -jravel

overlays on the release  rates of mercury from mercury

enriched sediments is summarized from Bonger and KnattaK

 [155]  as follows:
    It was found in laboratory studies that overburden

layers of sand or gravel 6 cm thick prevented the release ot

mercury from the underlying enriched sediments.  Layers less

than 6.0 cm thick were less effective in preventing mercury

loss from the sediments.  Little differences were ouserv^d

in the rate of release from organic or inorganic sediments.

It was noted that Tubificidae worms when present in the

sediments in large numbers apparently were responsible for

the vertical transfer of mercury.  This suggests that

additional coverage of mercury enriched sediments may be

required in areas where sludgeworm activity is hign.

    Although field tests were not conducted the approximate

cost of applying this abatement procedure in a

representative field situation were calculated.  The area

selected for economic analysis was the Trenton Channel of

the Detroit River near Wyandotte.  Cost estimates tor

treating .8, 10.1 and 20.2 hectares of mercury contaminated

sediment with 7.6 cm of sand overlay are listed in Taoles b

and 9.  This cost evaluation is preliminary, and such site-

dependent factors as local transportation, sediment

characteristics, topography of the area, water currents and

depth, weather conditions and the availability of labor,

materials and hardware would affect the actual costs.

                          Table 8

Estimated fixed/variable costs of distributing sand in an
area south of Wyandotte. I/

    Fixed Costs ($);

      Spreading Equipment System               20,000.00
      (i.e. swivel piler, conveyor,
      clam shell, fixtures, hopper, etc.)

    Variable Costs;

      Sand, dockside, per cubic meter               2.94
      Tug boat and crex*, per 12-hour day        1,900.00
      Deck scow, 612 to 765 m3  (500 - 1000 yd)
        capacity per day                          100.00
      Equipment barge, per day                     30.00
      Labor, per day (2)                           80.00
      Equipment maintenance, per day               10.00
I/ Source:  Bonger and Khattak  (155)

                          Table 9

Estimate of the cost  involved in the application or 7.o cm
Of sand to .8,  10.1 and 20.2 hectares of sediment
contaminated with mercury J/.


Fixed Costs($)
Variable Cost ($):
    Tug Rental
    Scow Rental

    Number of Days
    m  of Sand
    (Yards of Sand)
10. 1
tO. 2
4 1 ,000
.: ,^00
_ ______
J/  From:  Bonger and Khattak (155)

    Suggs, Petersen and Middlebrook (156)  conducted

laboratory investigations ot the effectiveness of several

agents in removing mercury from the water column ana tne

underlying sediments.  It was found that both elemental

sulfur and thio-organic compounds dispersed in recoverable

materials were capable of removing mercury.  However,

elemental sulfur coated on a cotton meshwork was found to be

most effective, particularly in anaerobic sediments.  It was

also found that the rate of removal of metallic mercury with


elemental sulfur was proportional to the surface aren of the

"mercury getter".

    Other mercury getters investigated, were poly vinyl

alcohol gel systems, paraffin, sulfur dispersed in paraffin,

sulfur tablets, cotton and. paper, plastics, paraffin-

thiourea, polyvinyl alcohol-cystene and iron oxides.  Of

these only the poly vinyl alcohol nel systems contain inrr

sulfur or phenyl thiourea were found to bo effective in

removing mercury from contaminated v:ater and sediments, but

were not considered applicable where sediment contamination

levels were beloxv' 25 to 50 mcr/1.  Cost for actual

application to  field situations were not provided, but a

research-demonstration test plan has been proposed.

    When a spill of hazardous  substances occurs, the

contingency plan of the appropriate agencies must  be

implemented immediately,  frequently under adverse

conditions.   Such an event occurred in Pond Lick reservoir,

Ohio,  in 1971.  The following  summary of that experience  is

condensed from  reports prepared by PycJ-man, Edgerly,

Tomlinson and Associates,  Inc.  (157) and by Nye (158) of  the

Ohio Department of Natural Resources.


The Pond Lick Lake  Incident  - A Case S^udy

    On June 2,  1971, Pond Lick Keservoir  (known locally as

Shawnee Lake) near  Portsmouth, Ohio was maliciously poisoned

with about U.5U  liters of an endrin solution mixed with

strychnine treated  corn.  Pond Lick Lake is aoout JOU meters

long and approximately 75 meters wide at its widest point,

with maximum and average depths ot 12 and U.5 meters,

respectively.  Fortunately at the time of the poisoning, the

lake was thermally  stratified, thus restricting tne toxic

substances primarily to the epilimnioru

    The effects of  the poison were immediately apparent..

The entire fish population was destroyed, and the only

aquatic vertebrates surviving were tadpoles which were

apparently unaffected by the pesticide.

    Pond Lick Lake  discharges to the Ohio River via Poaa

Lick Creek and Turkey Creek.  The total distance separating

the lake from the Ohio River is less than 16 kilometers.

Cincinnati, on the Ohio River about 160 kilometers below the

confluence point, was vitally concerned about its water



    As a means of containing t.he pesticide within tae lake,

the spillway was sandbagqed and an earthen dan. wa^ built

upstream on the inflowinq Pond Lick Creek.  Tne creek was

then diverted around the lake via a 25.4 cm aluminum pipe

and two 13,620 liters per minute pumps.  Paqs of activated

carbon were added to the spillway to remove the pesticide

seeping through, and the seepage was pumped hack into tne


    At the time the spill was discovered endrin

concentrations of 9 mg/1 were present in tne epilinrnion

waters with lower concentrations below the thermocline.

Strychnine was not detectable in the lake.

    Since endrin is extremely toxic, even in concentrations

as low as 0.2 mg/lr is  highly stable and can be conceritrateu

biologically by factors of  10,000, it was imperative that

essentially all the endrin  be removed as rapidly as

possible.  A heavy rain would overload the by-pass system

releasing the contaminated  lake water to the receiving



Suggestions  considered  for  resolving the problem were  as

          1.   Dilution
          2.   Spray irrigation
          3.   Adsorption -  fcentonite, fly ash
          U.   Biological removal
              a.   Sewage
              b.   Fish
          5.   Chemical  treatment
              a.   Cracking
              b.   Oxidation with ozone
          6.   Adsorption and filtration through activated carbon,
          7.   Physical removal by use of tank trucks.
          8.   Filter through alfalfa hay.

Most of the suggestions were discarded as impractical or

    An initial attempt was made to reduce the concentration
of endrin by broadcasting approximately 3,178 kg of 40 mesn
activated granular charcoal over the lake.   This proved to
be ineffective as there was insufficient contact time before
the charcoal settled out.


    A pilot plant was next constructed of a U5.7 cm diameter

pipe, 2.U meters high and filled with activated cnarcoal.

Water from the lake was run into the bottom and out the top

of the cylinder.  This system proved to be very etreceive as

the endrin concentration of lake water which passed through

the column was reduced to near zero.

    A large treatment, plant was then designed based upon trie

success of the pilot plant.  A channel filter was

constructed consisting of a 122x2UUx549 cm wooden box

containing gravel and a 1.8-meter deep charcoal bed.  Water

was pumped through the bottom.  The filter was effective but

slow, with a flowthrough rate of about 30U liters per

minute.  It was discovered that underground springs were

feeding the lake faster than it could be filtered, so an

additional charcoal filter was constructed in the spillway

outlet, with the filtered water diverted into a stilling

flume and retained until analysis indicated that endrin

concentrations were below 0.1 mg/1.

    Analysis of the lake sediments indicated that enurin was

being adsorbed by sedimented organics.  Since the la*e level

was not being decreased as rapidly as desired, another

filtering device, constructed to hold 166 bales ot hay, was


designed based upon another pilot plant study.  This syste

could handle approximately 5.7 m^ per minute with no

evidence of endrin detectable in the discharge,  hnen the

lake was eventually drained, endrin concentrations in tne

sediments along the bank were approximately 100 mg/ky.

Concentrations in the lake bottom sedimctnts were much lower.

    The bottom and sides of the lake were cleaned and

scraped, and the spoils disposed ot in a prepared area

outside the watershed.  Approximately U,9UO cubic meters of

sediment were distributed over a .8 hectare spoil area to a

depth of U5.7 cm and mixed with clay.  Three months alter

the poisoning event, the lake was fertilized,  the DanKs

reseeded, the lake refilled and fish restocked.  Total

estimated costs were $100,000.

    The Pond Lick Lake incident serves to demonstrate

in the event of a hazardous substance spill, no matter how

hopeless the case appears to te, a possible solution may

exist.  In the Pond Lick Lake case the cooperative ertort of

Federal, State and county governments and various local

agencies, private consultants and industries proviuea a

solution to the problem.


    The control of hazardous substances in the aquatic

environment has been the target of efforts by industry,

universities and governments.  The various aspects o± trie

problems are discussed in the Proceedings of the 1972

National Conference on Control of Hazardous Materials Spills


    Several state and local governments have established

statutes dealing with various aspects of lake management and

rehabilitation as a means of protecting inland lake

environments.  Kusler (160) has summarized the state and

local statutes which establish preventive or remedial

programs, lists applicable statutes and sets out examples of

representative statutes.  Kusler  (160) points out that

explicit statutes authorizing specific state or local

programs for lake protection, management and rehabilitation

are rare, and that protection and iranagement estimates are

often badly fragmented among several state agencies ana

local units of government.  This fragmentation of efforts

coupled with high costs and lack of technical expertise have


discouraged comprehensive lake protection,  management and

rehabilitation efforts (160).

    Problems relating to lake  shore development regulations,

shoreland management including economic impacts ot

artificial lake development and legal problems of property

owners associations are addressed in Various Inland Lake

Renewal and Shoreland Management Demonstration Projecc

Reports (161 - 165).

                         Section V
1.    Greeson, P. E.  1969.  Lake Eutrophication -
       A natural process.  Water Kes. Bull. 5:16-30.

2.    Pomeroy, L. P., E. E. Smith and C. N". Grant.   1965.
       The exchange of phosphate between estuarine  water
       and sediments.  Limnol. and Oceanoqr. 10:lb7-17J.

3.    Hayes, F. P. and J. E. Phillips.  1958.  Lake  Water
       and Sediment.  IV.  Radiot-hosphorus equilibrium'
       with mud, plants, and bacteria under oxidizea ana
       reduced conditions.  Limnol. and Oceanoqr. 3:

4.    Sackett, W. G., A. J. Patten and C. W. Rrown.
       1908.  The solvent action of soil bacteria upon
       the insoluble phosphates of raw bone meal and
       natural rock phosphate.  Zentralblatt f.
       Backteriol. 2:688-703.

5.    Sperber, J. T.  1958.  Solution of apatite by  soil
       microorganisms producing crqanic acid.  Aust. J.
       Agr. Res. 9:778-781.

6.    Johnston, H. W.  1959.  The solubilization of
        "insoluble"  phosphates. V.  The action of  some
       organic acids on iron and aluminum phosphates.
       New Zealand. J. Of. Sci. 2:215-218.

7.    Wang, T. S., S. Y. Cheng and H. Tung.  1967.
       Extraction and analysis of soil organic acids.
       Soil. Sci. 103:360-366.

8.    Sperber, J. A.  1958.  Release of phosphate trom
       soil minerals by hydrogen sulfide.  Nature

9.   Hayes, F.  P.  and  c.  C. Coftin.   1951.   Padioactive
       phosphorous exchange of  lake  nutrients.
       Endeavour  10:78.

10.  Mackenthun,  K. .-1  . and W.  M.  Ingram.   1967.
       Biological  associated  problerrs in  fresh
       water environments:  their  identification,
       invest iqat.ion,  and control.   U.S.  Dept.
       Interior,  FWPCA, U.S.  Government. Printing  Ottice

11.  Postqate,  J.  R. and  L. L.  Carrrbell.   1966.
       classification  ot  uesulf ovibrio species,
       the non-sporulating sultate-reducirig  bacteria.
       Bacteriol.  Rev.  30:732-738.

12.  Postqate,  J.  R.   1970.   Nitrogen fixation by
       sporulating sulfate reducing  fcacteria including
       rumen strains.  J. Gen.  Microbiol  63:137-139.
13.  LeGall, J., S. C. Senez et F.  Pinchinoty.
       Fixation de  1* azote par les  fcacteries  sulfatc-
       reiuctricos  ot Cciracterisation 

19,  Ohle, W.  1962.  Der Stofthauhalt der se^n als
       Grundlage einer allgmeiner Stoffwechseldyndmik.
       der Gewasser.  Kieler Merresferschg. 18:107-120.

20.  Organic matter in Natural Waters.  1970.  D.  w. hooa,
       ed.  Institute of Marine Science Ossasional
       Publ. No. 1.  University of Alaska.

21.  Marine Food Chains.  1970.  J. H. Steele, ed.
       University of California Press.

22.  Riley, G. A.  1963.  Organic aggregates in sea
       water and the dynamics of their formation and
       utilization.  Limnol. and Oceanogr. 8:372-Jal.

23.  Kuznetsov, S. E.  1968.  Recent studies on t;.e role
       of microorganisms in the cycling of substance
       in lakes.  Limnol. and Oceanogr. 13:211-22**.

2U.  Seki, H.  1968.  Relation between production  and
       mineralization of oraanic iratter in AburatoUbo
       Inlet, Japan,  J. Fish. Res. P. Can. 25:625-bJ7,

25.  Hugh, R.  1970.  A practical approach to the
       identification of certain ncn-fermentativo
       Gram-negative rods encountered in clinical
       specimens.  J. Confr. Publ. Health. Lab. Dir.

26.  Seki, H., J. Skelding and T. F. Parsons,  19faB.
       Observations on the decomposition of a marine
       sediment.  Limnol. and Oceanogr. 13:UUO-4U7.

27.  Rendricks, C. W.  1971.  Enteric bacterial metaoolism
       ot stream sediment eluates.  Can. J, Microoioi.

28.  Guillard, R. R. L. and J. H. Fyther.  1962,   Stuaies
       on marine planktonic diatoms. I. Cvclot.ella nai^g
       (Hustedt) and Datonula confervacea  (Cleve)  Grari.
       Can. J, MicrobiolT~8:229-239.


29.  Burckholder, P. R. and  L. M.  Eurckholder.   195t>.
       Vitamin  R12  in  suspended  solids  and  marsh muds
       collected along the coast of Georgia.  Limnoi.
       and Oceanogr. 1:202-208.

30.  Burckholder, P. R. and  L. M.  Purckholder.   195H.
       Studies  on B vitamins in  relation to productivity
       of Rahia fosforescenti, Puerto Rico,   Bull.  Mar.
       Sci. Gulf and~Carribbean  8:201-113,

31.  Kurata, A. and M.  Kimata.   1968.   Studies  on marine
       bacteria producing vitamin  B12.  I.   On  the
       distribution of  marine bacteria  producing Vitamin
       B12 and  the vitamin production of them.   Res. Inst.
       Sci. Kyoto Univ. 31:26-34.

32.  Seki, H.   1964.   Studies on iricrobial  participation
       of food  cycle in the  sea.   Inter. J.  Oceanog.
       Soc.  (Japan) 20:122-134.

33.  Convery, J. J.  1970.   Treatment Techniques for
       removing phosphorus from municipal v-astewaters.
       Water Pollut. Contr.  Res. Ser. No. 17010-01/70.
       U.S. Government  Printing Office, No.  1970-3d9-9jJ

34. Cecil, L. K.  1971.  Evaluation of  processes available
      for removal of phosphorus from wastewater.  fc.PA
      Project Report,  wo. 17010.  DRF.

35.  Rohlich, G. A. and P. D. Uttormark.  1972.   Wastewater
       treatment and eutrophicaticn.  Nutrients  and
       eutrophication.   Special Symposia, Vol.  I.
       pp. 231-243.

36.  Malueg, K. W., R.  M. Brice, D. K.  Schults,  and D. P.
       Larsen.  In Press.  Interiir Report No. 1,  The Suagawa
       Lake Project; lake restoration by nutrient removal
       from wastewater effluent.  EPA Internal  Report.
Thomas, E. A.  1969.  The process of eutrophication
  in Central European lakes.  In:  Eut.rophication:
  causes, consequences, correctives.  Proceedings ot
  a Symposium, National Academy of Sciences,
  Washington, D. C.  p. 37.

^8.   Pennypacker, S. P.  1967.  Renovation of wast^water
       effluent by irriqation of forest land.  J. hater
       Pollution Control Federation.  39:285.

39.   Law, J. P., Jr.  1969.  Nutrient removal from enricnea
       waste effluent by the hydroponic culture ot cool
       season grasses.  Water Pollution Control Research
       Series 16080.  U.S. Dept of Interior.

UO.   Bouwer, II.  Water quality aspects of intermittent
       systems using secondary sewage effluent, U.S. water
       Conservation Laboratory, Phoenix, Arizona.  Paper  *b.

41.   Tilstra, J. R., K. W. Malueg, W. C. Larson.  1972.
       Removal of phosphorus and nitrogen from wastewater
       effluent by induced soil percolation.  J. Water
       Pollution Control Federation.  UU:796-805.

U2.   Seidel, K.  1967.  Wasserptlanzen reinigen abwasser.
       Umschau in Wissenschaft und Technik.  67:565.

41.   Hemens, J. and G. J. Stander.  1969.  Nutrient
       removal from sewage effluents by algal activity.
       In:  Advances in Water Pollution Research, Prague
       1969, Proceedings of the 4th International Conterence.
       pp.  701-715.  Pergaman Press.

44.   Anderson, G. C.  1961,  Recent changes  in the trophus
       nature of Lake Washington - A review.  In:  Ai»jae
       and  Metropolitan Wastes, Trans. 1960  Seminar.
       U.S. Department of Health, Education  and Welfare.
       pp.  27-33.

U5.   Edmondson, w. T.  1968.  Water quality  management and
       lake eutrophication:  The Lake Washinaton case.
       In:  Water Resources Management and Public Policy,
       edited by T. II. Campbell and R. O. Sylvester.
       University of Washington Press,  pp.  139-17tt.

46.   Edmondson, W. T.  1969.  Eutrophication in North America.
       In:  Eutrophication:  causes, consequences, and
       correctives.   National Academy of Sciences, Wasnington,
       D. C.  pp.  12U-149.

47.  Edmondson, W. T.  1970.  Phosphorus, nitrogen,  arid
       algae in Lake Washington after diversion  ot  sewage.
       Science 169:690-691.

48.  Emery, R. M., C. E. Moon, and E. E. Welch.   1971.
       Delayed recovery in a mesotrophic lake  following
       nutrient diversion.  Presented at the 38th Annual
       Meeting ot the Pacific NW Pollution Control Aosoc,
       Spokane, Washington.

49.  Sarles, W. B.  1961.  Madison's lakes, must  uroauization
       destroy their beauty and productivity.  In:   Aiyae
       and Metropolitan wastes, Trans. 1960 Seminar.
       U.S. Dept. of Health, Education, and Welfare.
       pp. 10-18.

50. Mackenthun, K. M., L. L. Lueschow and C. D. McNab.
      1960.  A study of the effects of diverting  tne
      effluent from sewage treatment ujon the  receiving
      stream.  Wise. Acad. Sciences, Arts and  Letters.

51.  Tenney, M. W., W. F. Echelberger, Jr., and T. C.
       Griffing.  1970.  Effects of domestic pollutiua
       abatement on a eutrophic lake.  Partial
       Report on FWQA Demonstration Grant No.  W?D-12t>.

52.  Laurent, P. J., J. Garaucher and P. Vivier.  1970.
       The condition ot lakes and tends in relation  to
       the carrying out of treatment measures.  5th
       International Water Pollution Research  Conference.
       Pergamon Press Ltd.  In Press.

53.  Sanville, W. D., and C. F. Powers.  1972.  Progress
       Report No. 1, Diamond Lake Studies-1971.  NEKP,
       Pacific NW Environmental Research laboratory,
       Corvallis, Oregon.

54.  Hamm, M. A.  1971.  Limnologische Untersuchungen an
       Tegernasee and Schliersee Nach der
       Abwasserfernhaltung, Wasser und Abv-asser-Forschurivj.
       Nr. 5.

55.  Thronson, R. E.  1971.  Control of erosion and sediment.
       deposition from construction of highways ana land
       development.  U.S. Environmental Protection Agency.

56.  National Association of counties Research Foundation.
       1970.  Urban soil erosion and sediment control.
       Dept. of the Int., Federal Water Quality
       Administration.  15030DTL05/70.

57.  Bogardi, J. L.  Sediment transportation in alluvial
       streams. 2nd Int. postgrad course on Hydrol Methoas
       for Developing Water Resources Management, Budapest,
       Hungary.  Jan-July, 1968.  Manual No. 13.

58.  Krumbein, W. C.  1968.  Statistical models in
       sedimentology.  In:  Sedimentolcgy 10:7-23.

59.  Barfield, B. J.  1969.  Prediction of sediment proriles
       in open channel flow by turbulent diffusion theory.
       Water Resources Res. 5:291-299.

60,  Brandt, G. H., E. S. Conyers, F. J, Lowes, J. M.
       Mighton, and J. W. Pollack.  1972.  An economic
       analysis of erosion and sediment control for
       watersheds undergoing urbanization.  NTIS Pb 2"09212.

61.  Maddock, T., Jr.  1969.  Sedimentation engineering
       Chapter VI:  Economic aspects of sedimentation.
       Proc. Amer. Soc, Civ. Eng. S. Hydraul Div. 95:191-207,

62.  The Lake Restoration Researchers Team.  1971.  Tne Lake
       Trummen Restoration Project.  A Presentation,
       University of Lund, Sweden.

63.  Johnson, C. S.  1971.  Silt removal from a lake bottom.
       Interim Progress Report, EPA Project 16010-ELF.

6U.  Wisconsin Department of Natural Resources.  1970.
       Inland lake dredging evaluation.  Technical
       Bulletin No. 46, Madison, Wisconsin.


65.  Landner, L.  1970.  Lake Restoration.  Trials with
       direct precipitation of Phosphorus in polluted
       lakes; the binding of mercury in lakes; trials with
       grass carp.  Swedish Water and Air Pollution Research
       Laboratory, Stockholm, Sweden.

66.  Jernelov, A.  1970.  Phosphate reduction in lakes by
       precipitation with aluminum sulfate.  Fifth
       International Conference on Water, San Francisco,

67.  Peterson, J. O. , J. P. Will, T. L. Wirth, and S. M.
       Born.  1973.   Eutrophication Control:  Nutrient
       inactivation by chemical precipitation at Horsesnoe
       Lake, Wisconsin.  Tech. Bull. No. 62.  Wisconsin
       Dept. of Nat. Res., Madison,

68.  Gahler, A. P.,  W. D. Sanville, J. A. Searcy, C. F.
       Powers and W. E. Miller.  Studies on lake restoration
       by phosphorus inactivation.  NERP, Pacific NW
       Environmental Research Laboratory, Corvallis,
       Oregon.   (In manuscript) .

69.  Oglesby, R. T.   1969.  Effects of controlled nutrient
       dilution on the eutrophication of a lake.  In:
       Eutrophication:  causes, conseguences, and correctives,
       National Academy of Sciences, Washington, D. C.
       pp. U83-U93.

70.  Born, S. M.  1970.  Final Pepcrt  (May 1, 196b-January
       1971) .  The Inland Lake Renewal and Management
       Demonstration Project, submitted to Upper Great
       Regional Commission,  pp. 5-10.

71.  Welch, E. E., J. A. Buckley, R. M. Bush.  1972.
       Dilution as a control tor nuisance algal blooms.
       J. Water Pollution Control Federation.  UU:
72.  Bhagat, S. K., J. F. Orsfcorn.  1971.  Water quantity
       and quality studies of Vancouver Lake, Washington.
       Washington State University, Pullman, Washington.

73.  Sketelj, J. and M. Rejie.  1966.  Pollutional
       of Lake Bled.   In:  Advances  in Kater Pollution
       Research, Vol.  I, Proceedings of 2nd International
       Conference, Tokyo, up.   345-362.

7U.  Tenney, K. F. , W. F. Echelberger, Jr.  1970.   Fly  usn
       utilization in  the treatment  of polluted waters,
       Bureau of Mines Information Circular H4S8, Asn
       Utilization Proceedings.  pp. 237-265.

75.  Fast, A. W.  1971.  The effects ot artificial  aeration
       on lake ecology.  U. S.  Govt. Printing Office,
       Washington, D.  C.
76.  Wirth, T. L. and  K. C. Dunst.   1967.  Li.mno logical
       changes resulting from artificial destratiticatiou
       and aeration of an impoundment.  Progress .

82.  Lackey, R. T.   1972.  Evaluation of two methous or
       aeration to prevent winter kill.  The Progressive Fisn
       Culturist.  3u (e) :175-17b8.

83.  Malueq, K. w. , J. R. Tilstra, D. w. Schults  ana c.  c.
       Powers.  In Press.  The effects of  induced aeration
       upon stratification and eutrophicat ion  processes in  au
       Oreqon farm pond.  International Symposium on Man-maue
       Lakes.  Knoxville, Tennessee.

84.  Bernhardt, H.r P. Cooley. J. A. Steel, J.  E.  Kiaiey ana
       H, Ambuhl.  1967.  Impoundment destratif ication  by
       mechanical pumpinq.  J. San, Civ. Amer.  Soc,  civ. Ernj.
       93(SA-4) :136-143.

85.  Leach, L.  1968.  Eufaula Reservoir aeration researcti.
       Proc. Okla. Acad. Sci. 49:174-181.

86.  Symons, J. M.  1971.  Artificial destratiticatj.on  in
       reservoirs.  Report of AMWA Committee on Quality
       Control in Reservoirs.  J. Amer. Water ViorKs  Assoc.

87.  Fast, A. W.  1971.  Effects of articitial  destratit ication
       on zooplankton depth distribution.  Trans.  Amer.  ir'ish
       Soc, 2:355-358.

88.  Symons, J. M. , W. H. Irwin, E, I. Robinson ana
       G. G. Pobeck.  1967.  Impoundment destratif ication
       for raw water quality control usinq either  mecaanical
       or diffused-air pumpinq.  J, Amer. Water Works
       Assoc. 59:1268-1291.
89.  Robinson, E. L. , W. H. Irwin and J. M. Symons.
       Influence of artificial destratitication on pianKton
       populations in impoundments.  Trans. KentucKy acaa.
       Sci. 30, Nos. 1 and 2.

90.  Lackey, R. T.  1973.  Artificial reservoir destratit" ication
       effects on phytoplankton.  J. Water Poll. Control  Fed.

91.  Sheffield, C. W. , R. T. Kaleel.  1970.  Lake Apopka  and
       aquatic weeds. Hyacinth Control Journal 8:45-47.

92.  Smith, S. A., J. O. Peterson, S. A. Nichols ana  o. A.
       Eorn.  1972.  Lake deepening by sediment consolidation
       Jyme Lake.  Inland Lake Demonstration Project  Ke^ott
       University ot Wisconsin and the Wisconsin Decrement
       of Natural Resources.

93.  Smith, G. F., T. F. Hall, P. A. Stanley.   1967.   Eurasian
       water milfoil in the Tennessee Valley. Weeds Ib:9b-y8.

9U.  Cook, A. H., C. F. Powers.   1958.   Early hiocnemical
       changes in the soils and waters of artificially created
       marshes in New York, New York Fish and Game Journal

95.  Oswald, W.. J. and C. G. Golueke.  1968.  Harvesting and
       processing ot waste-grown  iricroalgae.  In:  D.  F.
       Jackson  (ed.).  Algae, Man and the Environment.
       Syracuse University Press.  p. 371-389.

96.  Golueke, C. G., W. J. Oswald and H. K. Cree.  1964.
       Harvesting and processing  sewage-grown planktonic
       algae.  Serl. Repl. No. 6U-8.  Sanitary  Fny. Res. ^aty.
       U. of Calif, Berkeley, Calif. Mimeo.

97.  McGauhey, P. H., P. E. Eliasson, G. Pohlick, A.  G.
       Ludwig, and E, A. Pearson.  1963,  Comprehensive
       study on protection of water resources of La*e Tahoe
       Basin through controlled waste disposal.  Lake Tanoe
       Area Council, Al Tahoe, Calif.

98.  Levin, G. V. and J. M. Barnes.  196U.  Harvesting or
       algae by troth flotation.  Final  Report, Public health
       Service Contract No. PH86-63-75.

99.  Anon.  1957.  Sewage stabilization  ponds in trie  Dax.otas.
       Vol. I and II.  Joint Report of the North and  soutn
       Dakota Depts. of Health, and the  U. s. Depts ot
       Health, Education and Welfare, Washington, D.  C.

100. Neel, J. K., J. H. McDermott, and C. A. Monday,  Jr.
       1961.  Experimental lagooning ot  raw sewage
       at Fayette, Missouri.  Jour. Water Pollution cont.
       Fed. 33(6):603-6U1.

101. Bush, A. F., J.  D.  Isherwood  and S.  Fodqi.
       Dissolved solids  removal  frcm waste- water by a-Ljae.
       Jour. San. Snq. Div. ,  Am, Soc.  Civil Ena. t>^,
       SA3: 39,

102. Boqan, R, H.   1961,  The use  of aiqae in removing
       nutrients fronr domestic sewage.   In:  Alqae ani
       metroplitan  wastes.  TR W61-3,  [J,  S. Public Health
       Service, cinn. , Ohio.

103. Oswald, E, J. , C. G. Golueke,  H.  c.  cooper, H.  K, crje,
       and J. c, Brenson.   1962.   viator  reclamation,
       alqal production  and methane f prrrenta^ ion in vva^te:
       ponds.  Manuscript No.  25,  Int. Conf.  W^ter Poliunon
       Res. , London.

104. Gates, W. E. and J. A. Borcharat.   196U.  Nitrogen dr^a
       phosphorus extraction  from  domestic waste water
       treatment plant eftluents by controlled  alijai
       culture.  Jour. Water  Pollution Control  Ft\i.  Ju:«*4j.

105. Livermore, D.  19SU.  Harvestinq  underwater weeds.
       Water Works  Ena.  Feb.   pp.  118-120.

106. Livermore, D.  F. and W.  E, Wundcrlich.   1969.
       Mechanical removal of  orqanic production  from
       waterways.   In:   Eutrophicat ion:   causes,
       consequences,  correctives.   Print inq and  Publ.
       Office, N.A.S., Washington,  D.  C.

107. Yount, J. L. and H. A, Grossman,  Dr.   1970.
       Eutrophicat ion control  by [ lant harvesting,  J.^ci
       42(5) :R173-P1R3.

108. Bruhn, H. D.,  D. F. Livermorr,  and  P .  O. Aboaba.   j.970.
       Physical properties and processir.q characteristics or
       macrophytes  as related  to mechanical harvesting.
       Paper #70-582.  Am. Soc. Aqr,  Engineers,  St.  Jose:>it,
       Michiqan (also avail,  from  ttTIS as PB  19B
109, Nichols, S. A.  1971.  The distribution  and  controx or
       macrophyte nioirass in Lake Vvinqra,  Wisconsin A
       Resources Center, Madison.  Final Completion D
       OWRR B-019-WIS (4) .   (Also avail, from  NTIS as

110.  Bagnall, L. O. , T. W. Casselman, J. W. Kesterson, J. F.
       Basleyr and H. E, Hellwiq.  1971.  Aquatic  toraye
       processing in Florida.  Paper #71-536.  Am. 6oc. Ayr.
       Eng. OWRR A-017-FLA(2) .
111. Koegel, R. G., H. D. Bruhn, and D. F. Livermore.
       Improving surface water conditions  through control
       and disposal of aquatic vegetation. Phase I:
       Processing aquatic vegetation for improved Handling
       and disposal or utilization.  Wise. Water resources
       Center, Madison, Technical Completion Report. UWh ii-
       oia-wis(U) .

112. Boyd, C. E.  1971.  The Limnoloqical  role of aquatic
       macrophytes and their relationship  to reservoir
       management.  In:  Reservoir fisheries ana limnology.
       Special publ.  #8 Am. Fisheries Soc. Washington,  D. C.
       pp. 153-166.

113. Goodson, J. B. and J, J. Smith.  1970.  Treatment  ot
       citrus processing wastes.  Water Pollution control
       Research Series *12060-10/70.  EPA, Water Duality
       Office, Contract WPRD 38-01-67,

11U. Mulligan, K. F.  1969.  Management of aquatic  vascular
       plants and algae.  In:  Eutrophication:  causes,
       consequences,  correctives.  Printing and Puol.
       Office,  MAS,  Washington, D. C.

115. Lange, S. R.  1965.  Commercial possibilities  ot dehydrated
       aquatic plants.  Southern Weed Conference, proceedings

116. Bailey, T. A.  1965.  Commercial jossibilities of
       dehydrated aquatic plants.  Southern Weed
       Conference, Proceedings 18:543-551.

117. Aboaba, F. O.  1971.  Physical processing characteristics
       of some aquatic macrophytes.  PhD.  Thesis, Univ. Wisconsin
        (Avail, as OWRR B-018-WIS ( 3) ) .

118. Cifuentes, J.  1971.  Screw  press design parameters for
       dewatering water hyacinth  (Eichornia crassipes) .  M.
       S. Thesis in Engineering,  Univ. Florida, Gainesville, Dept,
       Agr. Eng.  (WRSIC accession #W 72-03232.)


119. Abou-El-Fadl, M. , s. G. fcizk, A. F. Abciel Ghani, M.  K.
       El-Mofty, and M. F. A. Khadr.  1970.  Utilisation  of
       water hyacinth as an organic iranure with social reference
       to water-borne helminths.  J. Microbiol. U.A.K. J:2?-3U.

120. Lee, G. F.  1970.  Eutrophication.  Univ. Wisconsin
       Water Resources Center, Madison, Occasional Paper  §2,
       Eutrophication Information Program.

121. Rogers, H. H., Jr.  1971,  Nutrient removal oy water
       hyacinth.  M. S. Thesis, Auborn Univ., Alaoama.
       WRSIC accession #W72-04776.

122. Gerloff, G. C. and P. H. Krombholz.  1966.  Tissue
       analysis as a measure of nutrient availability for
       the growth of angiosperm aquatic plants.  Limnoi.  ana
       Oceanogr. 11:529-537.

123. Cottam, G.  1969.  Changes in water environment
       resulting from aguatic plant control.  Proceeuin«js of
       meeting, joint industry/Government Task Force on
       Eutrophication.  Univ. Wisconsin, Madison, Nov. 2<«-^5,

12U. Steward, K. K.  1970.  Nutrient removal potential of
       various aquatic plants.  Hyacinth control Journal

125. Taylor, P. G., R. P. Dates, and R. C. Robbings.  1971.
       Extraction of protein from water hyacinth.  hyacinth
       Control Journal 9:20-22.

126. Seidel, K.  1968.  Elimination von Schmutz-uria
       Ballaststoffen aus belastet-en Gewassern durcn
       hohere Pflanzen (Elimination of substances ot
       mud and ballast from waters by higher plants).
       Zeitschrift Pitalstoffe-zivilisations KranKheiten  Mr. 4.

127. Kiefer, W.  1968.  Pflanzen tioloqische Reiniyung
       von Abwasser (Biological wastewater treatment with
       plants).  Umschau:210.

128. Greer, D. E., and C. D. Ziebell.  1972.  Biological
       removal of phosphates from vater. JWPCF UU:

129. Corey, R. B., A. D. Hasler, F. K. Schraufnagel, and T.
       L. Wirth.  1967.  Excessive water fertilization:
       Report to water subcommittee, Natural Resources
       Committee of State Agencies.  Madison, Wisconsin

130. Bailey, W. M., and R. L. Boyd.  1972,  Some observations
       on the white amur in Arkansas,  Hyacinth Control
       Journal 10:20-22.

131. Opuszynski, K.  1972.  Use of phytophagous fisa to
       control aquatic plants.  Aquaculture 1:61-74.

132. Sport Fishing Institute Bulletin.  1972.  Grass carp
       problem.  No. 240.  Washington, D. C,

133. Hasler, A. D., and E. Jones.  1949.  Demonstration of tne
       antagonistic action of large aquatic plants on al^ae
       and rotifers.  Ecology 30:359-364.

134. Porter, K. B,  1972.  Control of natural phytoplanxton
       populations by grazing zooplankton.   (Abstract or
       paper presented at AAAS-Ecological Society) Bull.
       Ecol. Soc. Am. 53:9.

135. Mattox, K. R., D. Stewart, and G. L. Floyd.  1972.
       Probable virus infections in four qenera of green
       algae.  Can. Jour. Bot. 18:1620-1621.

136. Safferman, R. S., and M. E. Morris.  1963.  Algai virus:
       isolation.  Science 140-679-680.

137. Padan, E. and M. Shilo.  1969.  Distribution of
       Cyanophages in natural habitats. Verh. International
       Verein. Limnol. 17:747-751.

138. Shilo, M.  1971.  Biological agents which cause lysis ot
       blue-green algae.  Mitt. International Verein. Limnol.

139. Cappleman, L. E.  1972.  Detached leaf culture of
       Eichornia crassipes and application to the culture
       of its pathogens.  M. S. Thesis, Florida Atlantic
       University, Boca Raton  (unpublished).


140. Sculthorpe, C. D.   1967.  The biology of  aquatic vascular
       plants.  Edward Arnold  (Publishers) Ltd. ,  London.

1U1. Gillies, P.  (Ed.)   1972.  The Water Hyacinth.   Water
       News Letter 1U:2.  Water Information Center,  Inc.
       Publ. Port Washington, L. I., N.Y.

142. Coulson, J. R.   1971.   Prognosis for control of water
       hyacinth by arthropods.  Hyacinth Control  Journal

143. Hawkes, R. B.  1965,  Domestic phases of  program designed
       to use insects to suppress alligator weed.  Proc.  ii.
       Weed Conf. 18:584-585.
144. Baloch, G. M. , A. G. Khan, and M. A. Ghani.
       Phenology, biology and host-sepciticitty ot  some
       Stenophagous insects attacking Mvriophvllum  spp.  in
       Pakista.  Hyacinth Control Journal 10:12-16.

145. Blackburn, P. D. , and L. W. Weldon.  1965.  A  f resn water
       snail as a weed control agent.  (Abstract) Proc. S.
       Weed Conf. 18:589.

146. Sguros, P. L. , T. Monkus , and C. Phillips.  1965.
       Observations and techniques in the study of  tne
       Florida manatee - reticent but superb weed control
       agent.  Abstract. Proc. S. Weed Cond. 1.8: 588.

147. Fitzgerald, G. P.  1971.  Algicides.  Literature
       Review No. 2,  Eutrophication Information Program,
       the University of Wisconsin Water Resources  Center.

148. Fitzgerald, G. P.  1966,  Use of potassium permanganate
       for the control of problem algae.  Jour. Ainer. Water
       Works Assoc. 58:609-614.

149. Timmons, F. L.   1970.  UNESCO Meeting on Ecology and
       Control of Aquatic Vegetation, December 16-18, 196 a.
       Paris. Hyacinth control Journal fl(2):23-26.

150.  Lambou, V. W.  1972.  Problems of mercury emissions into
       the environment of the United States.  Report to tne
       Working Party on Mercury, Sector Group on Unintended
       Occurrence of Chemicals in the Environment, OrlCD,
       Environmental Protection Agency,

151.  Jernelov, H.  1969.  Conversion o± mercury compounds.
       In:  Chemical fallout.  Charles C. Thomas, Springfield,

152.  Trukayama, K.  1966.  The pollution of Minamata Bay and
       Minnemata Disease.  Adv. Disease.  Adv. Water Pollution
       Research, Proc. Int. Conf. 3:153-180.

153.  Study group on mercury, hazards.  1970.  Hazards of mercury.
       Special report to the secretary's Pesticides Advisory
       Committee, Dept. of Health, Education and weitare ana
       Environmental Protection Agency.

15U.  stephan, D. G.  1971.  Trip report:  Finland and Sweden,
       Feb. 21-25, 1971.  Assistant Commissioner, Research
       and Development, Water Quality Office, Environmental
       Protection Agency.

155.  Bongers. L. H. and M. N. Khattak.  1972.  Sand and gravel
       overlay for control of mercury in sediments.  Kesearcn
       Institute for Advanced Studies, prepared for tne
       Environmental Protection Aqency, Washington, D. C.

156.  Suggs, J. D. , D. H. Petersen and J. B. Middlebrook, Jr.
       1972.  Mercury pollution control in stream and lake
       sediments.  Advanced Technology Center, Inc.  Prepared
       tor the Environmental Protection Agency, Ortice of Research
       and Monitoring, Washington, D. C.

157,  Pyckman, Edgerley. Tomlinson and Associates, Inc.
       Pesticide poisoning of Pond Lick Lake, Ohio
       investigation and resolution, June 2 - July 5, 1971.
       Final  report prepared for the Environmental
       Protection Agency, Division of Oil and Hazardous
       Materials, OWP, Washington, D. C.

158. Nye, W. R.  1972.  The hazarcous material spill
       experience in Shawnee Lake, Ohio - a cas<°
       In:  Control of hazardous materials spills.  Proc.
       1972 Nat. Conf. on the Control of Hazaroous Materials
       Spills, March 21-23, 1972, Houston,
159. Control of hazardous materials S[ills,  1972.  Proc.
       Nat. Conf. on the Control cf Hazardous Materials
       March 21-23, 1972, Houston, Texas.

160. Kusler, J. A.  1972.  Survey: lake protection ar.u
       rehabilitation leqislation in the United States.
       Inland Lake Renewal and Shcreland Manaqemerit
       Demonstration Project Report. Univ. of uisc,

161. Yanqqen, D. A.  1971.  Preservinq lakes by protectin-j
       their shorelarids.  In:  Prcceedinqs Workshop
       Conference on Reclamation of Maine's Dyinq ^ais.e»,
       Univ. of Xaine, Banqor, March 24 and 25, 1971.  Conf.
       Report No. 2, Water Resources Center, Univ. ot i-iaine,

162. Klessig, L. L. and D. A. Yanqqen.  1972.  Wisconsin Lake-
       Shore Property Owners Associations:  Identification,
       description arid perception of lake problems.  Inlana
       Lake Renewal and Shore land iVanauement Demonstration
       Project Report, Univ. of hisc. , Madison.

163. Kusler, J. A.  1971.  Artificial lakes and lana
       subdivisions.  Report from Wisconsin Law Review,
       Vol. 1971, No. 2, Univ. of Wise., Madison.

16U. Lejeune, H.  1972.  Economic impacts of artincial ia*e
       development:  Lakes Sherwood and Camelot - a case
       history.  Inland Lake Renewal and Shorelanci Management
       Demonstration Project Report.  Univ. of Wise., Maaisoa

165.  Yanqgen, D. A. and Z. L. Zigurds.  1972.  Leyal problems
       of property owners1 associations for large water-
       oriented recreational housing complexes.  Inland Lake
       Renewal and Shoreland Management Demonstration
       Project Report. Univ. of Wise., Madison.

                         Section VI

                       LAKE PROBLEMS

    Water quality problems have resulted as increased

amounts of wastes have been introduced to aquatic receiving

systems.  Molecules of diverse chemical structures have L»een

synthesized resultinq in compounds which are refractory to

dcqradation.  The ability of microorqanisms to metdDoliiie

pollutants to carbon dioxide and water and thus to remove

them from the aquatic environment is the. primary biological

method for "self purification" of waters.  As organisms

advance evolutionally, the inherent ability to assimilate

and deqrade new and diverse products is rabidly diminished.

Evidence of this is seen in the alarming levels ot certain

chlorinated hydrocarbons.  Although contaminants may

originate from a variety of sources, they can usually be


broadly classified as industrial, municipal or agricultural

Industrial Wastes

    Industrial wastes often create unique problems in  cne

aquatic environment.  They are frequently in the rorm  or

liquid containinq substances which are aifticult it not

impossible to remove from drinkinq water.  The magnitude of

the problem is brought to liqht. by the fact that tnero are

approximately 240,000 water usinq establishments in tne

United States which consume 75,700 mj  (20,000,000 gallons)

or more water  (1).  Industrial waste water efrluent has

three t.o four times more oxyqen-deirandinq wastes than  tue

total sewered population in America  (2).  As industries

expand and diversify the attendant problems ot industrial

effluents increase at a proportional rate.  Atmospneric

rain-out resultiriq from industrial stack and automobile

emissions also contribute to the contamination ot waterways.
    No detailed  inventory  of  industrial  wastes  is

however, as  seen  in Table  I,  the  airount  of  wat^r useu  ana

waste qenerated  is enormous.   Water  and  airborne wastes


contain organic and inorganic solids, suspended material,

toxic substances, and biological grcwth stimulants.

    The magnitude of industrial waste loading can be

illustrated by using thermal pollution as an example of tne

total problem.  The electric power industry, the single

largest producer of waste heat, and a contributor or other

pollutants, is increasing at a rate of 7.2 per cent

annually, almost doubling every ten years (U).  As seen in

Table II, this trend is expected to continue.  Otner

industries also require water for cooling purposes (faule

III).  The metal, chemical, petroleum and coal, paper, tood,

and various manufacturing industries are among those

requiring large quantities of cooling water.

    It has been estimated that by 1980 electric power

cooling operations alone will require the equivalent of one-

fifth the total fresh water runoff to the United states (4).

However, the thermal loading associated with power

generation is only one example of water quality degradation

caused by industry.  Other industries have effluents wnicri

can be more difficult to deal with.

                                                           TABLE  I

                                            Estimated Volume of Industrial  Wastes
                                                  Before Treatment,  19 f 4  I/
Volume Volune
(billion (billion

Food and kindred products
Meat Products
Dairy Products
Canned & frozen food
Sugar refining
All other
Textile mill products
Paper & allied products
Chemical 6 allied products
Petroleum & coal
Rubber & plastics
Primary metals
Blast furnaces &
Steel mills
All other
Electrical cmachinery
Transportation equipment
All other manufacturing
All manufacturing
For comparison: Sewered
population of the U.S.
I/ Columns may not add, due to
27 120,000,000 persons times 0.
T/ 120,000,000 persons times 0.
V 120,000,000 persons times 0.














S uspended









— —







452 m
0757 ko
0808 kg
times 365
times 365
times 365






Source:  (3)

                          Table II

      U.S. Electric Power - Past Use, Future Estimates
                                       In billion
Year                                 Kilowatt-hours
1912	    12

I960	   753

1965	1,060

1970	1,503

1975	2,022

1980	2,754

1985	3,639

Source:  (5)

                            T£BLE III

              Use of Cooling Water by U.S. Industry

Electric power

Primary metals

Chemical and allied products

Petroleum and coal products

Paper and allied products

Food and kindred products


Rubber ancl plastics

Transportation equipment

All others
                                          VJater Intake
(billions of
of ^ota
Source:   (5)

Municipal Wastes

    Municipal waste treatment accounts for the disposal of a
heterogeneous variety of liquid and solid material
comes from domestic  (55X) and industrial  (U5%) facilities
(tt).  Added to this constant, waste load is the periodic
storm sewer runoff, which in certain areas of the country
(Northeast, Midwest and Far West) may contain deicing
chemicals and organic and inorganic pollutants.  Domestic
waste treatment sewers service approximately two-tnirds of
the total population  (U).  of this sewered population,
approximately 60 per cent have adequate treatment facilities

    A major contribution of phosphates and nitrates to lakes
and reservoirs comes from municipal plants (U).  In addition
to the inorganic nutrients are various organic compounds,
such as detergents, which can act as a substrate for a
variety of microorganisms.  The organically and chemically
rich effluents serve as an ideal millieu for the growtn of
the endogenous bacteria in the receiving waters.  It is the
growth of these normal inhabitants which lowers the
dissolved oxygen and is reflected as biochemical oxygen
demand (BOD).

Agricultural wastes

    Agricultural wastes in waters originate basically trom

either fertilizers and pesticides supplied to growing crops

or as wastes from livestock.  Fertilizers contain

predominately nitrogen and phosphorus, which when applied to

the land, can wash into the aquatic environment.  These two

nutrients stimulate the growth of algae, bacteria and

aquatic weeds leading to a shift in the normal aquatic lite.

    Pesticide runoff is another problem associated with, out

not exclusive to, agricultural activities.  Productivity

reportedly has increased with the increased use ot

insecticides and the consequent reduction of plant pests.

However, in some areas, the cost ecologically has been

manifested in either the elimination of or decrease in

numbers and diversity of certain aquatic organisms.  As tne

population increases with attendant demands for more iooa a

continued, if not increased, pesticide use will be retired.

    Feedlot wastes are a potential contributor to tne

pollution of waters in various areas ot the country.  Modern

methods for raising beef cattle, poultry and swine, along


with dairy farm operations produce concentrated waste

sources of potential water pollution.  The animal wastes

produced today are estimated to be the equivalent ot trie

waste produced by 2 billion people (U).  This figure does

not necessarily mean that a proportional amount 01 animal

waste ends up in water, since much does not reach tne

aquatic ecosystem.  However, it is a measure of tne

pollution potential.
Miscellaneous Sources
Mine drainage

    Acid drainage comes from mines where the water and air

mix allowing the growth ot sulfur oxidizing bacteria.   As a

consequence of this growth sulfuric acid is produced

resulting in a pH, in extreme cases, of less than one.  It

has been estimated that in the Appalachia region, where 75

per cent of coal mine pollution occurs, about 168,000

kilometers of streams are polluted  (U).  Other mining

operations for phosphate, iron, copper, gold and aluminum

also are responsible for acid mine discharge.


Oil and Hazardous Materials

    Pollution of the aquatic environment due to oil

hazardous materials spills has grown steadily in the past

years.  As seen in Table IV, the number of spills over

15,900 1  (100 barrels) increased dramatically in a period of

one year.  The number of spills is expected t.o increase as

the flow of oil to refineries increases to meet rising luel

demands.  Disposal of spent motor oils and lubricants also

presents a problem.  It has been estimated that 1,J30,000

kiloliters of used oil per year have to be disposed ot by

gas service stations  (4).
TABLE  IV - Number of Reported Oil  Spills  in U.S. voters
          over  15,900 1  (100 Barrels)
                                   1968       1969

Vessels	        347        532

Shore facilities	        295        331

Unidentified	         72        144

Total	        714      1,007

Source:   (6)

Watereraft Wastes
    Pollution resulting from sewage discharged from
watercratt is primarily of health significance ratner tnan
organic or oxygen depleting significance.  It has oeen
suggested that the total potential sewage from vessels is
equal to a town of 500,000 people (U).  However, sewage
waste disposal from vessels can present a problem in
confined areas such as boat harbors and marinas.


    Impairment of lakes can result from an isolated instance
of the introduction of a contaminant,  such as  occurs uuring
an accidental spill, through continuous or intermittent
industrial or municipal point source discharges, or through
surface runoff and contributions from tributary streams and
ground waters.

    The nature of contaminants and their effects on lake
environments vary widely.   In general, the various
contaminants can be grouped into categories based upon tiie
manner in which they affect a lake ecosystem.  The major
groups are the organic.wastes, inorganic nutrients, silts
and sediments, toxic substances, and heated waters.  Other


contaminants include radioactive wastes, various non-toxic

salts, and many others which produce a *ide ranae 01 etrects

on lake environments.  The impact of each of the major

groups of contaminants is discussed below under trie

respective headinqs of eutrophication, sedimentation,

thermal problems and selected toxic substances.  Kaaioactive

wastes and non-toxic salts are briefly discussed unaer the

heading of miscellaneous problems.

    Eutrophication may be broadly defined as nutrient or

organic matter enrichment, or both, that results in niqn

biological productivity and a decreased volume witniu a

ecosystem.  Eutrophication is, therefore, a process by wnicn

a lake gradually evolves from a condition of low

productivity  (oligotrophic) to a highly productive condition

(eutrophic).  Organic matter and nutrients are carried into

the lake by runoff and leaching frcm the drainage juasin,

stimulating increased biological productivity of all Kinds.

Products of erosion carried to the lake, ana excessive

quantities of organic matter, both plant and animal,

produced within the lake, lead to a gradual filling-iri, and


the lake becomes shallower and smaller.  The waters

consequently become generally warmer.  Footed aquatic plants

take over increasingly more  space, their dead remains

accelerating the filling ot  the basin.  Eventually tne la*e

becomes a marsh, upon which  terrestrial vegetation

progressively encroaches until the lake ceases to exist,

being replaced by a dry-land environment.  The laKe tnen,

not only evolves from oligotrophy to eutrophy, but, it tne

aging process is permitted to proceed to completion,

eventually is subjected to total extinction.
Natural and Accelerated	(Cultural) Futrophicatiion

    The gradual enrichment and aging of lakes is a natural

process which takes place under completely natural

conditions, in the absence of man, provided that a

sufficient nutrient supply is available from the drainage

basin.  For lakes situated within a relatively sterile

drainage area, the aging process may span geologic time.

Other lakes, subject to heavy nutrient loading from

naturally fertile drainage basins apparently were higril>

eutrophic prior to their exposure to civilization.


    The role of man in the eutrophication process may

completely override natural forces.  Many lakes have been

observed to become enriched and to age very rapidly trom uie

effects of domestic or industrial waste disposal, or from

drainage basin disruptions or alterations resulting trom

man's activity.  Nutrient flux to lakes can be increased

manytold by, for example, the input of nutrient-containiay

wastes, agricultural fertilization, clearing of forest

lands, and roadbuilding and other construction.  Many lakes

exposed to increased nutrient input are currently exhibiting

symptoms of rapidly increased rates of eutrophication; triis

condition is referred to as accelerated or cultural

eutrophication, and it is an ever-growing problem in tne

United States and other countries.
Consequences of Eutrophication

    The progressive eutrophication of a lake results in

distinct physical, chemical, and biological changes,

generally in the direction of impairment of the lake*s

utility to man.  Oligotrophic lakes have the highest 4uality

water (although perhaps net the best tishing), and tne water

is well suited to a variety of uses,  Oligotrophic

good multi-purpose lakes.
    Very definite changes in the quantity and quality or tne

biota occur as eutrophy proceeds.  With the increased

productivity associated with accelerated rates of

eutrophication comes the filling of the basins with

organic materials and sediments resulting in an i

oxygen demand on the overlying waters.  The increased ox/gen

demand may result in total depletion of oxygen in the cooler

bottom waters during the summer, accompanied by an increase

in the products of respiration and decomposition, namely

carbon dioxide, methane, and hydrogen sulfide.  Tnese

developing anaerobic conditions result in replacement ot

existing benthic organisms with less desirable types, dua

cold-water species of fish, such as trout and salmon, are no

longer able to exist; they are replaced ly forms tolerant of

higher temperatures.  Curing the winter, under heavy ice.- and

snow cover, shallow eutrophic lakes may be subjected to

complete oxygen depletion.  As a result entire fish

populations may be eliminated, as frequently happens in tne

northern states.


    In addition to restricting fish populations, hignly

eutrophied lakes are undesirable aesthetically and with

respect to water use.  Alqal blooms produce taste and odor

problems, and create unsightly surface scums which

discourage water contact recreational activities.  Dense

growths of rooted aquatic plants may accompany, or occur in

place of, the nuisance algal blooms.  Such intense plant

production greatly inhibits use of the water for swimming,

fishing, or boating.  Accumulation of algal mats ana dense

weed growths are most pronounced near shore, where mar^s

contact with the water is greatest.  The accumulated algal

masses begin to decay in a short period of time, resulting

in extremely foul-smelling conditions.  Excessive plant

production, then, can render a lake virtually unfit for

recreational purposes or shoreline development.

    In addition to their deleterious effects on aesthetic

and recreational aspects of lakes, the excessive growth of

aquatic plants can seriously affect water quality.  Large

quantities of planktonic algae frequently, and to a serious

extent, increase the rate of clogging of sand filters at

water treatment plants.


    Probably even more serious is the increased frequency of

taste and odor problems resulting from algae in eutrophic

lakes.  These can originate from either living or dead

algae, or from the fungi which grow on algae remains.

Tastes and odors may be produced fcy members of all the major

algal groups: the blue-greens, greens, diatoms, and

flagellates.  No one group is responsible.

    Still other water quality problems resulting trom

eutrophication are increased color in the water, resulting

from plant growth, and concentrations of iron, manganese,

and sulfide which may occur as the result of oxygen


    Certain blue-green algae have fceen shown to have toxic

effects on animals.   Domestic animals, such as cattle arid

sheep, as well as fish and aquatic invertebrates,  may be

susceptible to toxic substances excreted by algae  of tnis

group.  Water in which certain tlue-green algae have Dloomed

may produce death in mammals and fish even when tne algal

cells themselves are excluded.  There is also evidence that

allergic reactions and gastrointestinal disturbances may

result in humans from contact and ingest ion of la*e water in

which algae exist- in blocm proportions.



    Sediments are an integral part of lake ecosystems,
providing habitats for benthic organisms and serving di a
pool for nutrients necessary for aquatic plant growtn.  Ion
exchanges and nutrient transport the mud ana wat^r
significantly affect the lake(s productivity.  Accelerated
erosion and subsequent deposition of sediments in lakes can
result in a degradation of these natural ecosystems.  In
terms ot volume, sediment is today's greatest water
pollutant.  It reduces the storage capacity of reservoirs,
fills lakes and ponds, clogs stream channels, buries
habitats and increases turbidity.
Effects of Sediment

    Sediments influence the physical, chemical ana
biological processes occurring in lakes.  Perhaps one ot the
most obvious is the filling of lakes and impoundments by
sedimentation thus restricting the usetul life of tne water
body.  A detailed survey of 148 artificial  lakes  (7)
revealed the average annual loss of water retaining volume


which as shown in Table V, varies between 0.5 to 2 percent


                          Table V


    No. of Lakes             % Annual Volume Loss

         3U                       0.5
         39                       0.5 to 1.0
         39                       1.0 to 2.0
         36                       2.0

Source:  (7)

    Suspended sediments increase turbidity and reuuce the

depth to which light penetrates below the water surrace thus

restricting the growth of photosynthetic flora ana reaucirig

the lake's productivity.  Increased turbidity also affects

aauatic food chains by impairing the sight and food

gathering efficiency of predators.  The European inland

Fisheries Advisory Commission  (8)  reports the effect ot

inert suspended solids on freshwater fish as shown in Table



                          Table VI


    Concentration,                Eftect

          25                 No evidence of harmful ettects
         25-80               Good to moderate fisnenes
         80-UOO              Good fisheries unlikely
          UOO                Poor fisheries

Source:  (8)

    High concentrations of suspended materials may also ue

deleterious to aquatic vertebrates by reducing their

resistance to disease, preventing the successful development

of eggs and larvae, modifying natural migrations ana

reducing the abundance of food.  Buck  (9) removed the fish

from 39 farm ponds having a wide range of turbidities, and

restocked the ponds with largemouth Mack bass  (Microptcrus

salmoidesl , bluegill  (LejDCjnis macrochirus) and red-ear

sunf ish (Lepomis micro.lojDhus) .  After two growing seasons,

the fish crop was harvested and the effects of various

turbidity levels on reproduction were compared as seen in

Table VII.


                         TABLE VII


    Yield, kg/ha    (Ib/acre)      Turbidity,  mq/1
Source:   (9)
    Buck  (9) also reported that larqemouth black

crappies  (Pomoxis) and channel catfish  (Ictalurug  iuactat.usl

qrew more slowly in a reservoir where the water hdU an

average turbidity of  130 mg/1 than in another reservoir

where the water was always clear.
    Lake sediments provide habitats for benthio organisms

including bacteria, fungi, algae, flagellates, cilidtes,

sponges, mussels, worms, insects and snails.  Sorre ot tnese

orqanisms have commercial value, and others are essential

links in food chains which sustain tish, water fowl ana

other wildlife.  When accelerated erosion resulting from

farming, timber harvest and other activities causes iieavy

sediment inputs to a lake, the benthic flora and tauiid

be blanketed with layers of silt,  Feedinq qrounds and


spawninq sites as well as entire populations may be

destroyed, causing radical changes in the lake ecosystems.

    By the ion exchange process at the mud-water interface,

nutrients are either released to the bottom water or are

removed from the water by the sediments.  These ion

exchanges are caused by oxidation-reduction (redox)

reactions.  The oxidation potential of a solution is

determined by the type and proportion of oxidized and

reduced ions in the solution.

    When oxygen is available to the lake bottom, the top

strata of its sediments are oxidized.  This layer acts as a

barrier against diffusion from the mud to the water and

holds nutrients in the sediments.  However,- when a lake's

benthos becomes anaerobic this layer becomes thinner ana may

disappear entirely.  As the oxidized layer of sediments is

destroyed, nutrients in reduced form (i.e., Fe + + , Mn«-+, NH3

and P) are released from the sediments into the water ana

are available tor assimilation by the biota.

    Suspended solids entering a lake may adsorb bota

nutrients and toxic materials removing them from possible

involvement in the food web as deposition of suspended


particles occurs.  Gumermar^s  (10) study of sterile

sediments from Lake ^rie and Lake Superior demonstrated tnat

the maximum phosphate adsorbing capacity of the sediments is

in the top 3.5 mm, and is reduced to zero below 1u nuru

Gumerman (10)  also found that the release of adsorbed

phosphorus from sediments will maintain sufficient

concentrations of phosphates to sustain alqal growths tor

some time after phosphate input has ceased.  Anotner study

on phosphate equilibrium tetween reduced sediments and water

(11)  revealed that sediments in a reduced state will adsorb

less phosphate than the same sediment in an oxidized state.

Consequently,  under low oxygen tensions at the muu water

interface,  phosphates are released into the water by

chemical reduction reactions and by a physical tendency oi

the sediment particles to adsorb fewer molecules and ions.


Sources of Sediments

    Lake sediments fall into two general categories,

depending upon their origin.  Autochthonous sediments are

generated within the lake itself, and are often composed

primarily of decomposed aquatic plants.  A highly productive

eutrophic lake will have a larger proportion of

autochthonous sediments than an oligotrophic lake.

Allochthonous sediments are transported into the lake from

an outside source.  Under natural conditions these sediments

are generally the result of three geologic processes -

erosion, transportation, and deposition.  Human activities

associated with forestry, agriculture, mining, uruan

development, highway construction, and channelization otten

tend to accelerate the natural geologic processes tnereby

increasing several fold the natural sedimentation rates or


    Timber harvesting operations may be responsible ror

increased sedimentation.  On a steep forested slope in

Oregon clear-cutting with no roads increased sedimentation

three times more than that of a control slope  (12).  Erosion

on patch-cut areas with forest reads has reportedly

increased sedimentation more than 100 fold.


    Runoff from cultivated land carries a heavier silt load

than that from either forest or grassland.  However, soil

conservation practices, including contour plowing and strip

cropping, have greatly reduced agricultural land erosion.

    Strip mine runoff and erosion of mine tailings are a

major source of sediment in some areas.  The annual sediment

yield from unmined areas of Cane Branch, Kentucky, averaged

about 8.8 metric tons per square kilometer (13).  Erosion ot

mine spoil banks in this same drainage basin resulted in an

average annual yield ot 9,455 metric tons per square

kilometer, and erosion of abandoned coal haul roads at steep

grades was also severe.

    Urban land development resulting in exposure of Dare

soil at construction sites is also a cause of accelerated

erosion.  Yorke and Davis (14, 15)  indicate that a direct

relation exists between the sediment yield of a basin ana

the area of land under construction, the season ot tne year,

slope of the land, and proximity cf construction sites to

stream channels.  Streamflow and sediment data were

collected at gauging stations on Bel Pre Creek in Montgomery

County, Maryland, between 1963 and 1967.  Pasture and

woodland dominated the landscape prior to March 1965,


however, between March 1965 and August. 1967, 15 percent of

the watershed was developed into garden apartment ana

townhouse complexes.  Suspended sediment discharged

increased 1U times as a result of this construction  (1u,

15).  A study on the effect of urbanization on sediment

yield in New Jersey  (16)  also suggested that yields are

proportional to the degree of urbanization.  The low

population density pine barrens yielded U - 14 metric tons

of sediment per square kilometer per year, while the

urbanized Delaware River area yielded 9-35 metric tons per

square kilometer per year, and in the Philadelphia area, the

yield was up to 175 metric tons per square kilometer per

year.  This corresponds to the 70 - 175 metric toas per

square kilometer per year sediment yield reported  (17) for

the Washington and Baltimore urban and suburban areas.

    Sediment transported by storm runoff was measured  (18)

for 25 storm events on a 23.5 hectare watershed in

Kensington, Maryland.  Between July 1952 and January  1962,

89 single family homes were built and 171 metric tons of

sediment per acre were lost from this watershed.  It is

apparent that sediment yield is controlled  by the combined

effect of runoff and vegetation cover, both of which are

affected by human use of the land.


    The extent of erosion and transportation ot soil exposed

by highway construction was studied  (19) in a 11.6 square

kilometer watershed in Fairfax County. Virginia.  Seaiment

yield was measured at gauging stations and revealed tuat,

with average precipitation, erosion vias 10 times that

normally expected for cultivated land and 200 times tnat

expected of grassland and 2,000 times that expectod from

forest land.

    Eolian sediments are composed of material that was

borne, deposited, produced, or eroded by the wind.  Lakes in

evergreen forests are at times so covered with pine pollen

that their surface takes on a golden hue.  This material is

eventually deposited as organic sediment.  Lakes nearly

industrial plants or construction sites also receive fallout

which may contain lead, mercury, and a host of otner

Thermal Pollution

    With the settling of North America vast stands of rorest

canopy and tall prairie grass were removed, exposing the

soil beneath to direct solar radiation.  An obvious result


was a qeneral warming of the continent's streams ana lakes,

Today an urbanized society and an industrial economy, witn

continually rising demands for power plants and factories,

many of which discharge thermal energy, contribute to tae

warming of our waterways.
Effects of Thermal_Pollutign

    An increase in ambient water temperature caused by

thermal effluents entering a lake may increase the metabolic

rate of aquatic organisms and cause a corresponding increase

in the food required for inaintenance of body weight with no

growth.  Members of the freshwater family of fishes,

Centrarchidae, reportedly ate three times as much tooa at 20

C as at 10 C  (20), and brown trout, Salmo trutta, snowed a

constantly increasing feeding rate from 10°C to  19°C, above

which the rate declined abruptly.  When water temperatures

rise, the swimming speeds of fish may also be affected.

Acclimated goldfish increased their swimming speeds as

temperatures  were increased from 5°C to 20°C  (21).  Cruising

speeds remained fairly constant until temperatures reached

30 C and then dropped off rapidly with further temperature



    The optimurr temperature  for maximum qrowt.h depends on

available food.  Young sockeye saliron raised in  tan*s witn

surplus food grew best at temperatures near  15°C  (22), ana

at higher or lower temperatures their growth rates ueclined

sharply.  However, when given a small daily  food ration

these fish grew best at near 5°C and did not grow at *11 at

15°C.  Increasing the temperature of a relatively barren

water body, resulting in increased food requirements or trie

fish populations, could conceivable lower the fish

supporting capacity of the lake or impoundment.

    Increased water temperature reduces the solubility of

oxygen thus reducing the dissolved oxygen available to

aquatic fauna.  This harmful effect is intensified because

the oxygen consumption of aquatic vertebrates is

approximately doubled for every ten degrees* C rise in

temperature (23).

    Fishes will adapt to higher temperatures, but the

success of this process depends en the absolute temperature,

the length of exposure to high teirperature and the rate ot

temperature change.  Gradually exposing fishes to higher and

higher temperatures acclimates them to these elevated

temperatures, but it lessens their ability to survive at low


temperatures  (2<*) .  It follows that the thermal shock causeu

by a large reduction in thermal effluent, ciurir.q a power

generating station's shutdown, could be more damaging to

aquatic biota than the original water temperature increase.

Meyer  (25) points out that subtropical fishes are living

much closer to their thermal limit than are polar species.

Thus thermal pollution may be more critical in soutuern

states than in northern states-

    Elevated water temperatures may stimulate the activity

of parasites and disease.  Hedgpeth and Gonar  (26) noteu

that maintaining bivalves in warm waters had the

disadvantage of  increasing the predatory gastropoa activity,

since oyster and mussel pests such as £rosa^£inx ana inais

thrive at warmer temperatures.

    Many biological cycles are initiated 1-y a temperature

stimulus.  Such  an impulse induces sexual activity in marine

animals  (27).  Salmon do not spawn it the water temperature

is too high.  The ability of a species to adapt- to an

incremental temperature rise may fce different at various

ontogenic stages.  For example, fish egos and larvae may

have more sensitive temperature requirements than the

adults.  Trout eggs do not hatch if they are incuoatea in


water that is too warm.  and some  fish species require a

winter chill period tor successful reproduction.   In the

vicinity of a thermal outfall fish might hatch too early in

the sprinq before their natural food has become plentitul.

Insect nymphs in an artificially warmed water body mignt

emerge too early for mating flight and be immobilized by tne

cold air.

    Sublethal temperature effects are also important.  For

example, the embryos of brown trout reared at high

temperatures (13°C)  yielded significantly smaller  embryos

than those hatched at- 2.8°C (28, 29),  A larger proportion

of the yolk is required tcr metabolism of embryonic tissues

at the higher temperature.

    Temperature increases within the ranges tolerateu by the

existing species tend to increase productivity, provided

t.hat light and nutrients are not limiting.   In nortnern

lakes added heat might make the water more attractive for

swimmers, but if this also resulted in extensive growtxi of

filamentous algae or other types of noxious vegetation tiie

advantage may be offset.  Increased algal productiviry may

also reduce the ability of predatory fish to see their prey.

When temperature ranges of existing populations are

exceeded, the species composition will change.  Below JO°C

diatoms are often represented by the largest members of

species  (30)  with green algae becoming more abundant at

temperatures from 30 C to 35 C.  Above 35°C blue-green alyae

freguently dominate the flora.
    If a thermal discharge tlows out over the surrace of the

lake, it will reinforce any tendency of the lake to stratify

into density layers.  Such stratification inhibits mixing

between the surface waters, which are generally rich in

dissolved oxygen, and the hypolimnetic waters, whicn may

become oxygon depleted if not replenished.

    Artificially induced temperature changes may trigger the

spawning migration at the wrong time of year.  Migrating

fishes must be able to avoid zones of unfavorable

temperature, as such zones may block the migration, and

spawning may be thwarted.


Sources of Thermal Pollution

    Power generating plants are the prime source or thermal

pollution.  This trend may continue since, in the Uriitea

States, power generation has doubled every ten years since

19U5, and indications are that future requirements will

demand an even higher rate of increase.  Other sources of

thermal pollution are industrial effluents, sewaue

effluents, and exothermic reaction associated witn oxidation

of organic matter.
Selected Toxic Substances

    Historically, natural weathering of mineral rich roc*

formations was the primary mechanism for release ot toxic

substances to the aquatic environment.  During the past

decades the man-induced release of naturally occurring toxic

materials combined with the discharge of synthetic toxic

compounds has far exceeded the injut through natural

weathering.  As a consequence of the increased ratt ot

input, low level residues of toxic substances are touna

throughout the total biosphere.



    The most widely dispersed of all man-made toxic

materials in the environment are the pesticides,  Inciuaed

in this rather heterogeneous group of compounds are ayents

designed to eliminate or control a variety of nuisance

organisms.  Many of the compounds are toxic or potentially

toxic to most life forms while others are specific in their

killing.  Both inorganic and organic compounds are used.

    Increased and frequently indiscriminate use of

pesticides during the past 20 to 30 years has resulted in an

ubiquitous low level residue of certain classes of these

compounds in the total biosphere.  Release of these agents

to the environment comes about not only as a consequence of

agricultural activity but also from manufacturing processes,

accidental spills, and disposal of containers and unused or

outdated agents.

    In the United States approximately 900 chemicals are

formulated into over 60,000 pesticidal preparations whicn

include the insecticides, fungicides, herbicides and plant

growth regulators  <31).  The majority of the pesticides in

use today are synthetic organic compounds, however.


inorganic pesticides and plant extracts are still used.  The

inorganic pesticides include such compounds as lead

arsenate, calcium arsenate, copper sulfate, mercuric

chloride and Paris Green.  The advent of the more etrective

organic pesticides has caused a decline in the use ot tae

inorganic pesticides.

    Certain botanicals or plant extracts such as pyrethrum

and rotenone are still in demand, as they are relatively

safe to handle, are quite specific in their killing, and do

not persist very long in the environment.  These pesticides

are widely used around livestock as they are relatively non-

toxic to mammals (31).

    The synthetic organic pesticides include the familiar

chlorinated hydrocarbons or organochlorines such as DDT,

dieldrin, chlordane and toxaphene.  Also included are the

organic phosphates (malathion,  parathion, etc.), and tne

carbamate insecticides such as carfcaryl (Sevin)  and several

fungicides, herbicides and defoliants.

    In 1967 the United States production of all pesticides

totaled 476.3 x 10^ kg (31).  Between the years 1964 and

1968 total pestici-de production increased at the rate ot 9


percent per year.  However, recent data indicate tnat tnis

trend has reversed, as total sales of synthetic organic

pesticides were down 6.9 percent in  1971 from th^  19c'J total

(32).  Present trends suqgest that the pesticide; industry

may he on a three-year plateau, after which s^les  are

expected to increase at an unknown ratr  (32).  The domestic

use of DDT and other persistent pesticides has beeu

declininq in recent years, reflecting a shift to the ust of

the less persistent chlorinated hydrocarbons and organic

phosphates.  Between the years 1956  to 1970 domestic

supplies of the chlorinated hydrocarbons dropped crom nearly

110.8 million kq  (2UU million Ibs) to about 14 million Kg

(31 million Ibs).  Conversely, during the same period,

production of the orqanophosphates increased from  J.2

million kg  (7 million Ibs) to 25.9 million kq  (57,000,000

Ibs)  (33).  Recently the Administrator of the United States

Environmental Protection Agency issued an order restricting

the use of DDT primarily to Public Health Officials and

physicians for the control of disease vectors, lice and ror

health quarantine  purposes  (34).  This order, which oecame

effective on January  1,  1973r may result in substantially

increased use of other  insecticides  for  insect control.


    The major pathways of pesticides  into  the  fresh water

environment are through direct application on  surrace waters

and from surface runoff  (31).  Industrial  and  domestic

sewage, and fallout from atmospheric  drift and precipitation

also contribute to the contamination  of waterways by


    Upon reaching a stream, downstream transport of

pesticides occurs through movement of the  solubilized

fraction and residues sorbed onto suspended or saltated

particles.  As a result of downstream transport, pesticide

concentrations in upstream reaches tend to diminish rapidly,

while levels in the downstream reaches and in receiving

lakes and reservoirs may be increased substantially.

    Sediments of lakes and reservoirs, particularly those in

eutrophic water bodies rich in organics, have a hign

affinity for pesticides, and act as sinks or pools for tne

residues.  Consequently, pesticides may be removed from tne

water and incorporated into the bottom sediments tairly

rapidly.  If siltation rates are high, pesticides in lake

sediments may be effectively isolated from the overlying

waters and removed from involvement in the food web.  On tne

other hand in lakes with lower siltation rates, sedimented


pesticides may be taken up by the benthie biota, which is in

turn consumed by fish and ether predators and thus the

pesticides are reintroduced into the food web.  Pesticide

entrapment in lake sediments may be only temporary and

persist only during the period in which the lake is

thermally stratified.  Once turnover occurs, if mixing is

complete, the pesticides may be released from the sediments

and redistributed throughout the water.

    The recovery rates of lakes treated with pesticides were

studied in Oregon, where two mountain lakes were treated

with the organochlorine, Toxaphene  (35).  One lake was deep

and biologically unproductive and the other shallow and rich

in aquatic life.  The shallow lake  recovered rapidly and

trout were restocked within one year.  Restocking ot trout

in the deep lake, however, was delayed for 6 years due to

toxic levels of Toxaphene in the water.  The reasons given

tor the slower recovery ot the deep lake were thermal

stratification, slower flow through time and reduced

biological activity  (35).

    All organic pesticides are subject to degradation,  with

most pesticides, depending upon environmental conditions,

degradation may be complete in a few days to a  few months.


The orqanophosphates,  for example, are readily  hyarolizea  in

alkaline water at high temperatures, however, a*-  reaucea &U

and temperatures they  persist for several months  (Jb).   ine

non-persistent pesticides, as with the organophos^hates,

although acutely toxic, do not pose long term hazarus  to

aquatic life and apparently are not accumulated throuyn the

food chain.  The organochlorine compounds, however, arc-

highly resistent to degradation, or the degradation proaucts

may be persistent.  These compounds may be accumulatea by

the biota directly from the water (37)  or through trie rood

chain, resulting in concentrations in the tissues oi higher

trophic level animals that iray be several thousand times

that found in the ambient waters.

    That persistent pesticides are rapidly removed rrom tne

water and concentrated in the sediments and biota was

demonstrated by Bridges gt al (38)  who described tne

dispersion and persistence of DDT in a farm pond.

Sufficient quantities of DDT were applied to a pona to yiela

a 0.02 mg/1 concentration in the pond water.  The

distribution of DDT in the water, sediments and biota was

observed for about 18 months.   DDT had disappeared from the

water after 3 weeks.   Maximum concentrations in tne

sediments of 8.30 mg/kg were recorded one day after


treatment, but had declined nearly to pre- treatment levels
after 8 weeks.  Vegetation samples revealed maximum
concentrations of 30.7 mg/kg one-half hour after treatment,
and after eight weeks contained 5. 1 mg/kg.  DDT
concentrations in the new vegetation crop, one year alter
application corresponded to post treatment levels.
Accumulation in fish of DDT and its metabolites reacned 3 to
U mg/kg within 1 month after treatment,  concentrations in
excess of 2 mg/kg were still present in fish when the study
was terminated.

    High  level pesticide residues in lakes have posed
problems  in recent years by interfering with the
reproductive patterns of fish or rendering them unfit for
consumption due to excessive contamination.  Concentrations
of DDT exceeding 4.75 mg/kg in the eggs of lake trout
resulted  in up to 100 percent mortality in developing try in
New York  lakes whose watersheds had been treated witn DDT
for gypsy moth control  (39).
    In Lake Michigan similar mortalities of coho salmon
were attributed to DDT, dieldrin and PBC concentrations in
the eggs  (31).  Reinert  (41) found DDT and dieldrin in
fishes from all the Great  Lakes,  concentrations in Lake


Michigan fishes were found to be  2 to  7 times as nigh  as

those in tish from the other Great Lakes.  Samples rrom

canned coho salmon had DDT and dieldrin concentrations of

7.10 and 0.09 mq/kg respectively.  Concentrations in adult

salmon caught just prior to spawning exceeded 12 ing/kg JDT

and 0.1U mg/kq dieldrin.  Levels  in excess of those

established by the FDA have resulted in Lake Michigan coho,

and several other species, being  removed from the interstate


    The behavior of pesticides in lake sediments ana tneir

availability for recycling back into the biota are not tuily

understood.  Studies on the rates of interchange across muu-

water interfaces and between the vater and the biota are

needed before the magnitude of the problem of pesticide

pollution in lakes can be thoroughly assessed.

    The problems of mercury contamination in Unitea States

waterways were drawn to public attention in April 1970, wrieii

Canadian investigators reported mercury pollution in Lake


St. Clair and other boundary waters  (42).  Subsequent
investigations by the United States Federal Water Duality
Administration (now the Environmental Protection Agency)
revealed that the mercury pollution problem was not limited
to the Great Lakes area, but was of national scope  (42).

    Mercury is a particularly hazardous contaminant in
aquatic systems, owing to its tendency to be transformed
from a relatively immobile inorganic metal to a highly  toxic
organic form by the biological process of methylation.  Tne
methylation process is accomplished by certain aquatic
bacteria living in the bottom muds  (43) , and all inorganic
mercury introduced for aquatic systems is potentially
subject to bacterial methylation, and subsequent uptake by
the biota.  Aquatic organisms are able to concentrate
methylmercury directly from the water or through the tood
chain  (42 - 47).  In general mercury in fish food organisms
increases at each trophic level of the food chain  (48) .  A
concentration factor of 5,000 or more from water to fi*e rids
been reported (49) and methylmercury magnification in  brook
trout  has been shown to exceed 10,000 after long term
exposure  (50).  Such factors as the metabolic rate, food
selection and the epithelial surface area of the individual


fish have been implicated as parameters which affect the
rate at which mercury is concentrated by fish  (W, 51).
    The toxicity ot mercury compounds to aquatic organisms
has been summarized by various investigators with widely
differing results.  It is established, however, that the
toxic level of mercury is affected by several aspects ot
water quality including termperature, pH, organic pollution
loading, hardness, alkalinity, heavy metal loadings ana
dissolved oxygen  (50).

    In respect to toxicity in natural waters, it is
methylmercury which is of primary concern.  Experiments at
the National Water Quality Laboratory indicate that 0.2 mg/1
methylmercury will kill fathead minnows within 6 to 6 weeks
(50) .  Toxicity data from the same laboratory on
invertebrates, Gammarus and Daphnia. a top minnow and a
brook trout is said to indicate than none are more sensitive
that the fathead minnow (50) .

    Plankton is particularly sensitive to mercury poisoning.
Exposure of phytoplankton to concentrations of 0.1 ug/1 of
methylmercury compounds caused a significant reduction in


photosynthesis, and at levels of 0-50 ug/1 photosynthesis

was stopped  (52).

    Sources of mercury release to the environment include

natural weathering, burning of fossil fuels, mining,

farming, industrial operations, hospitals, laboratories and

a host of others.  Sources of mercury input to the

environment, both man made and natural, are summarized by

Lambou  (42).  The natural weathering process is said to

release a maximum of 230 metric tons of mercury to the

environment yearly, whereas the amount released by burning

coal is on the order of 3,000 tons annually, and anotner

3,000 tons are emitted as industrial wastes  (53).

    Mercury pollution in the nation's lakes and rivers poses

a serious public health threat and has restricted sports

fishing and commercial fisheries operations in many areas.

Table VIII summarizes data compiled by the United States

Geological Survey on concentrations of total mercury found

in many U. S.  lakes and rivers.  Concentrations of total

mercury above  the minimum detection limit of 0.5 mg/1 were

found in  140 of  the 719 samples analyzed  (42).


    The problem of mercury pollution in lakes, particularly

the Great Lakes, is of such a magnitude that nany states

imposed fishing restrictions or warnings ot some type

because of high levels of mercury in fish taken from

contaminated lakes.  Table IX summarizes State restrictions

which were in effect as of September 1, 1970.  Mercury

levels in fish from selected areas of the Great Lakes are

summarized in Table X.  These data, based upon composite

homogenized samples collected by the U. S. Fish ana Wildlife

Service (55)  reveal relatively low total mercury residue

levels in the upper Great Lakes fishes, with increasing

concentrations in fishes taken in the lower Great l,aKes.

Average residue levels in the Lake Ontario fishes exceeded

the 0.5 mg/kg level for edible portions established by trie

Food and Drug Administration.

                                              TABLE VIII

                   Summary of total mercury measured in water sables fron U.S.
                 rivers and lakes obtained during October and November, 1970.  I/
                        .5 2/
 Number of samples with ug/1

.5-.9     1.0 1.9   2.0-2.9   3.0-3.9   4.0-4.9   5.0-5.9   6.0-C.->
District of Columbia
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Rhode Island
South Carolina
South Dakota
West Virginia
Puerto Rico
1 ^
10 3 - 1
_ » ^
"• ™
- ~ ~ "
34 —
2_ M •

™ ™ — —
_ • *
1 - - ~
• « — -
• • —
— — — —
«.«• — —
1 1
2« «
_ - - -
1 -
_ - - -
_ — — —
•» •» — —
— «. — —
- - - -
w •- — —
— «• — —
_ - - -
_ - - -
1 •• — —
- - - -
i r i _
44 10 3 2
__ __
_ _

_ —

~ ~
- —
— —
~ ~
~ ~
— —
•"• ""
— —
— —
— —
— —
— —
— ™*
-- —
— —
- -
— —
— —
- -
— —
— —
- -
— —
0 2
  I/  Summarized fror» Durum et^ al, (1970),

  2/  Below detection limit.

  Source:  (41)

                                                       TABLE  IX

                           State fishing  restrictions  because  of mercury  —  September  1,1970

      Closure of
     sport fishery

So. L. Huron, West
L. Erie take no
walleye, drum,
white bass


New York



L. Onondago

North Carolina

    Closure of
commercial fishery

Detroit R., L. St.
Clair, St. Clair R.
closed. So. L. Huron,
West L. Erie closed
to walleye, drum,
white bass
                         L. Erie closed to
                         Tombigbee P.. closed
                         Mobile R., Tensaw R.,
                         Mobile-Tensaw system,
                         Tennessee R. and
                         impoundments, closed
                         Pickwick L. closed
                         Pickwick L. closed
  Warning or catch and
release for sport fishery

Detroit R., L. St. Clair,
St. Clair R. catch and
release only
                         Wisconsin R., catch and
                         release recommended; no
                         more than 1 meal per week

                         Lake Erie - warning
                         released via news

                         L. Champlain, Erie,
                         Ontario, Oswego R.,
                         Niagara R., St. Lawrence
                         R. danger warnings

                         L. Champlain, L. Memphre-
                         magog, danger warning
                         L. Erie, danger warning
                         for walleye, drum, small -
                         mouth bass, white bass

                         Tombigbee R. up to Jackson
                         Dam, warning
                         Mobile  R., Tensaw R.,
                         Mobile-Tensaw system
                         Tennessee R. and
                         impoundments, warning

                         Pickwick L., warning

                         Danger  warning  (general)

                         Pickwick L., warning,
                         catch and release
 Embargo or warning
to commercial fishery

Embargo on species other
than walleye, drum,
white bass
                              Embargo on white bass
                                                                                L. Champlain, L.
                                                                                Memph remagog, emb argo
                                                                                on sales
Source:   (41)

                                                      TABLE X

                                        Mercury residues in fish, 1969 and 1970
                                                       Average Size
Station Location
Genessee River
St. Lawrence River
  Massena, N.Y.
  Port Ontario
Lake Erie
  Erie, Pa.
Lake Huron
  Bay Port,
Lake Michigan
Lake Superior
White sucker
Redhorse sucker  (R)
Rock bass
Northern pike
White sucker
Yellow perch
Yellow perch  (R)
Northern pike
Yellow perch
Yellow perch  (R)
White perch
Rock bass
White sucker
Freshwater drum
Yellow perch
Yellow perch  (R)
Channel catfish
Yellow perch
Yellow perch (R)
Bloater (R)
Yellow perch
Lake whitefish
Lake whitefish (R)
Lake trout

No. of























Avg. .24
Avg. .27
Avg. .84
Avg. .31
Avg. .07
Avg. .09
Avg. .17
                                                                                    No. of
                                                                       Average Size

                                                                      Lenoth  Weight
                                                                        (cm)     (kg)








Avg. .20

Avg. .52


Avg. .13


Avg. .07


Avg. .18


Avg. .10
Source:  (41)

Polychlorinated Biphenyls	(PCB* s)
    Recently, evidence has been compiled which indicates

that the PCB's are widely distributed throughout the

environment and that they can have adverse ecological ana

toxicological effects (54).

    An Interaqency Governmental Task Force (5U)

investigating the effects of PCB's in the environment

concluded that PCB's present a potential, but not an

imminent, health hazard, except for accidents which result

in high level exposure.   They have, however,  been tound in

fish and wildlife at levels which may adversely attect

aquatic organisms.

    PCB's have been manufactured commercially since 1929.

Historically PCB's in the United States were  used in a

variety of applications including plasticizers,  hydraulic

fluids and lubricants, surface coatings, inks, adnesives,

pesticide extenders, and microencapsulation of dyes for

carbonless duplicating paper.  Beginning in 1971, however,

the Monsanto Company reportedly reduced its production


volume, limiting its distribution to industries concerned

with the manufacture of electrical apparatus  (54).

    The water environment is thought to be the principal

sink and transport mechanism for PCB's, but there are tew

data on the removal, disappearance and sequestering or tne

substance in soils or bottom sediments of rivers, lakes,

estuaries or the ocean  (54).  Concentrations  in fresa water

away from any immediate source of waste discharges contain

less than one ug/1; sediment samples contain  up to several

hundred mq/kg near some industrial outfalls.

    PCB's are fat soluble and tend to be concentrated at

succeedinqly hiqher levels  as they pass through the various

steps  of the food chain.  They have been shown to accumulate

in fish and aquatic invertebrates to levels of 75,000 times

the ambient water concentration, and to be accumulated rrom

concentrations  as low as 0.05 uq/1  (54),

    PCB's are lethally toxic to  fish and aquatic

invertebrates in concentrations  of a few ug/1.  Metabolism

and excretion of PCB's by these  organisms is  very slow  (54).

PCB's  are only  moderately toxic  to birds and  mammals and

have not resulted in sufficient  mortalities to affect


populations, although they are thought to have contributed

to direct mortalities of some birds in the field.  The

sublethal physiological effects on wild animals appear to be

of greater significance than the lethal toxicity.
Phthalate Esters
    Phthalate ester residues have keen discovered in various

segments of the aquatic environment in North America,

occurring principally in water, sediment and aquatic


organisms in industrial and populated areas (55) .  Pntnalate

esters are widely used as plasticizers particularly in

polyvinyl chloride (PVC) plastics (50).  They have aiso been

used as insect repellents and in pesticide formulation to

retard volatilization.

    The acute toxicity of phthalate esters appears

relatively significant.  However, these compounds may be

detrimental to aquatic organisms at low chronic

concentrations.  Paphnia maqna. exposed to 10 mg/1 or   C

di-n-butyl phthalate showed a magnification of 6000 rold.

Upon transfer of* the organisms tc uncontaminated water.


however, approximately 50 percent of the material was

excreted within three days  (U9) .

    Arsenic compounds in the lake environments pose

potential hazards to aquatic life and wildlife and even to

man.  Arsenic enters waterways through various routes

including industrial and municipal waste discharges, mine

drainage, pesticides, lead shot, coal burning and smelting

of ores  (55).  Many detergents and laundry products contain

arsenic and their discharge in waste effluents contributes

substantially to arsenic contamination ot waterways as most

sewage treatment plants do not remove arsenic  (56).

    Arsenic was frequently applied to lakes and  ponas tor

the control of submerged aquatic vegetation.  Jn the period

from  1950 through  1962, over a.54 x  10^ kg  (1 million

pounds) of arsenic trioxide were applied to Wisconsin

for weed control  (57),  In Minnesota nearly U.31 x  10* kg

 (95,000 pounds) of arsenic trioxide were applied tor

submerged aquatic  plant control in 1958  (57).  Michigan and


other states also reported using arsenic trioxide as a weed

control agent, but in unknown quantities.

    It is known that arsenic can te biologically

concentrated and magnified in the food web  (58) as well as

accumulated in lake bottom muds  (59).  Some concentration

factors for certain marine organisms were given by Lowman

(58)  as follows: Benthic algae, 2000; mollusc muscle, 650;

crustacean muscle, UOO; and fish muscle, 700.  Concentration

in bottom samples taken in a treated lake ranged rrom 10 to

82 mg/kg (60),  Dupree  (59) studied the arsenic content of

the water,  soil and biota of lakes which had been treated

wit.h soil arsenite and subsequently drained and retilled ^

to 3 times.  The following year after treatment tne sodium

arsenate content of the water ranged up to 0.3 mq/1, in

plankton up to 7.4 mg/kg, and in bottom soil up to O.Jb

mq/kg.  These data suggested that arsenic could be released

from bottom muds providing a source to the water aria uiota

for a considerable period after application (59).

    The literature on the toxicity of arsenic is rather

confusing.   Arsenic is toxic to all animals with a central

nervous system and to most higher plants, but may not be

toxic to lower organisms (56).  The toxicity of arsenicals


is influenced by the form in which it is accumulated.  Tne

organic compounds which may reside in bottom sediments are

less toxic to man than the inorganic compounds, and the

pentavalent compounds  (arsenates) are generally much less

toxic than the trivalent arsenicals  (arsenites).

    Arsenic trioxide, a common aquatic weed control a«jent,

has been found to be harmful to  fish food organisms in

concentrations as low as 2.0 mg/1 over an unspecitiea length

of time  (56).  Conversely, concentrations as high as 17.1

mg/1 have been tolerated by minnows  tor one hour with no

harmful effects, and 10.0—20.0 mg/1 were tolerated Dy insect

larvae for an unspecified period of time without apparent

damage  (56).

    Sodium arsenite applied to experimental ponds in

concentrations of 4 mg/1 substantially reduced the numbers

of bottom organisms and reduced  bluegill production.  A U

mg/1 application also  killed microcrustacea and greatly

reduced  the rotifer population  (56).

    Because the relatively  insoluble arsenicals are present

in many  waterways, potential hazards tc those forms wnicn

accumulate arsenic, exist.  Arsenic  builds up slowly in the


body and, according to some medical sources, long term

arsenosis may not be detectable for two to six years or more

Ammonia and Sulfides

    Both ammonia and sulfides are potentially toxic

substances which are discharged from a wide variety of

industrial processes as well as municipal sewers.

    In unpolluted lakes ammonia and sulfides are usually

present in low concentrations.  However, in lakes receiving

decaying organic waste loads or with high natural organic

sediment content, the biological production of ammonia and

hydrogen sulfide in unusually high concentrations may pose

potential toxicity problems.

    During the summer stagnation periods the concentration

of free ammonia and hydrogen sulfide in lakes generally

increases with depth.  The bottom ooze may contain many

times the concentrations found in the overlying waters.  Tne

development of isothermal conditions and subseguent mixing

tends to distribute the dissolved gases throughout the water


column.  Consequently ammonia and hydrogen sulfide

concentrations in the bottom waters are usually lowest

during the periods of spring and fall overturn.

    The toxicity of both ammonia and sulfide is determined

to a large extent by the pH of the water.  Gaseous ammonia

is readily soluble in water forming ammonium hydroxide which

dissociates into ammonium and hydroxide ions in a pH

dependent reaction.  The toxic component of ammonia solution

is non-ionized ammonia.  Since the percentage of non-ionized

ammonia increases with increased pH, the toxicity of the

solution does also  (50).  Sulfides derive their toxicity

from hydrogen sulfide which is formed by reaction witn tine

hydrogen ion when added to water.  Hydrogen sulfide

dissociates in solution yielding the HS  and H  ions, and

the higher the pH the more complete the dissociation

reaction, therefore at higher pH values toxicity is reduced.

Numerous other factors such as temperature, dissolved oxygen

tensions and  free carbon dioxide concentration also

influence the rate of the reactions involving these

substances, hence influencing the toxicity.

    Toxicity  problems arising frcir excessive concentrations

of ammonia and hydrogen sulfide are more common in streams.


particularly those with a heavy industrial or municipal

water loading, than in lakes.  The potential tor toxic

problems exists in lakes, however, particularly in tnose

with high organic content in the sediments.  In snallow

northern lakes toxic levels of ammonia ir.ay develop under

heavy ice cover, and in combination with low oxygen tensions

contribute to stress conditions fcr aquatic life and in some

cases result in heavy fish mortalities.
Miscellaneous Problems
Non-Toxic Salts

    In the northern United States the practice ot applying

salts to streets and roads to control ice accumulations n<*s

become increasingly common.  During the past few decades the

amount of salt (mostly sodium chloride)  used for ueicing

purposes has increased exponentially, nearly doubling every

five years (61).  During the winter of 1969-70 an estimated

7,700,000 metric tons of salt were used for deiciag purposes

(61, 62).


    Much of the salt used for deicing purposes is carried

off in melt waters and transported to lakes via storm

sewers, qround and surface waters.  As a consequence of the

salt influx, the physical and chemical characteristics ot

the lakes may be changed substantially resulting in

significant ecological alterations and impairing tne IdKe's

utility as a resource.  Such is the case in Trondequoit Bay,

near Rochester, New York.

    The 435 km^ Irondequoit Bay drainage basin, with a 1970

population of 206,000 receives approximately  1 percent

 (77,000 metric tons) of the deicing salt used in the United

States  (61, 62).  Irondequoit Bay is connected to Lake

Ontario by a shallow channel, but little exchange of the

deeper bay water with the lake occurs.  The surface area ot

the Bay is 6.7 km ^ and maximum depth is 23 m  (61).

    During the winter of  1969-70, approximately 10 metric

tons of salt were stored  in the Bay, while 11,000 metric

tons went out  the outlet.  Approximately one  half of the

77,000 metric  tons applied to the roads were  stored in soil

and ground water, part of which will eventually reach the

Bay  (61).


    The winter influx ct salt resulted in the development of

a vertical density gradient sufficient to prevent the bay

from mixing during the 1970 and 1971 spring seasons.  it

also prolonged the period of summer stratification oy aoout

one month in the fall seasons ot 19f9 and 1970  (as compared

to the tall of 1939)   (61, 62).

    The full ecological consequences of the artificial

disruption of the circulation patterns due to salt influx

are not known.  One effect is to prolong the anaerobic

conditions of the bottom waters.  In a normal dimectic lake

anoxic bottom waters are replenished with oxygen duriny both

the spring and fall turnover.   Due to the lack of a complete

spring mixing period, the hypolimnetic water of Irondequoit

Bay remain anaerobic for about 9 months ot each year.

    It is not presently known how many of the Nation1s

northern lakes are similarly affected by salt runoff, as the

problem has received little attention until recent years.

Present trends in uses of deicing salts suggest that txie

potential for serious problems may be developing.


radioactive Wastes

    The development of the nuclear newer generating plart,

\vith its dependence upon large volures of coo linn water, has

introduced yet another fom of contaminant to the lake

environment - radioactive naterial.  As the nurber o^

nuclear generating stations increases, the number of nuclear

fuel reprocessino plants will also increase, sore impacting

on lakes.  The parallel development of these facilities will

increase the potential for rad.ionuclide contamination of

freshwater lakes.

    Radioactive wastes create a  unicue environrontal problem

in the  fom of ionizing radiations of varying eneraies, but

the primary consideration  is the potential  for  huran

exposure to these radiations.   In this rocrard,  radior.uclidos

of concern in the aqueous  environment  include cerium,

cobalt,  iodine, strontium, tritium, and Plutonium.
 Consequences  of Release of Radioactive Wastes

     Uhile many radioactive wastes are of very short half-

 life and low  energy,  others present problems because of

their persistence in the aquatic environment  (e.g., 129I,
137csj f re con cent rat ion potential in aquatic  food chains
leading to man, and subsequent toxicity to man.
Bioconcentration of radioiodine (131I) is of  special concern
in this respect since it is readily metabolized and
concentrated in the thyroid, and may become a significant
hazard via the cow-milk-child pathway.  In addition to
presenting a potential threat to the biota itself,
bioconcentrated radionuclides could render food sources such
as fish unsafe for human consumption.  Significant
quantities of soluble radioactive materials would also
endanger lakes used as municipal water supplies.
Discussions concerning bioconcentration of radionuclides,
and their transfer through aquatic food chains are contained
in respective publications of the Lawrence Livermore
Laboratory (63) and the National Academy of Sciences (64).

    The virtual non-removability of radioactive materials in
the aqueous environment coupled with the problem of
radionuclide reconcentration in the biota necessitates
careful control of nuclear facilities which release
radioactive wastes in the vicinity of freshwater lakes.

1.    Anon.  1971.  Water use in manufacturing.  1967
       census of manufacturing.  L. S. Dept. of commerce.

2.    Powers, T. J.  1967.  National Industrial Waste
       Assessment.  U.S. Department of Commerce.

3.    Parker, F. L. and P. A. Krerikel.  1969.  Thermal
       pollution:  Status of the Art.  Vanderbilt University
       Nashville, Tenn.  Report No. 3.

U.    Environmental quality.  1970.  First Annual Keport
       of the Council on Environmental Quality, pp. 30-39.

5.    Anon.  1968.  Industrial waste guide on thermal
       pollution.  Federal Water Pollution Control
       Federation, U.S. Department of Interior.

6.    Anon.  1970.  Clean water for the 197Q»s.  Federal
       Water Quality Administration, U.S. Department of  tne

7.    Happ, S. C.  1941.  Sedimentation in artificial
       In:  A symposium on hydrotiology.  Wisconsin Univ.
       Press, Madison, Wis.

8.    European Inland Fisheries Advisory Commission.
       1965.  Working part on water quality criteria
       for European freshwater fish.  Report on finely
       divided solids and inland fisheries.  Internat.
       J. Air Water Pollution 9:151-168.

9.    Duck, H. D.  1956.  Effects of turbidity on fisn ana
       fishing.  Trans. N. Amer. Wildlife Conf. 21:**29-6i.

10.  Gumerman, R. C.  1970.  Aqueous phosphate ana
       sediment interaction.  Proceedings 13th Conterence
       on Great Lakes Research, part 2.  Great Lakes Kesearcu
       Center, Detroit, Mich.

11.  Olsen, S.  196U.  Phosphate equilibrium between
       reduced sediments and water.  Verh. Int. Ver. Limnol. ,
       Copenhagen Univ., Denmark 15:333-341.

12.  Frearicksen, R. L.  1970.  Ercsion and sedimentation
       following road construction and timber harvest on
       unstable soils in three small western Oregon water-
       sheds, Forest Service Research Paper PNW-lOu.

13.  Collier, C. R.  1970.  In:  Influences of strip mining
       on the hydrologic environment of parts of beaver Cree*.
       Basin, Kentucky, 1955-1966, Geological Survey
       sional Paper 427-C, P C31-C46.

la.  Yorke, T. H. and W. J. Davis.  1971.  Effects of
       urbanization on sediment transport in Bel Pre CreeK
       Basin, Maryland.  In: Geological Survey Research
       1971, Chapter B, Professional Paper 750-B, ?
15.  Yorke, T. H. and W. J. Davis.  1972.  Sediment yields or
       urban construction sources, Montgomery County,
       Maryland, Geological Survey Open-File Report.

16.  Anderson, P. W. and J. E. McCall.  1968,
       Urbanization's effect on sediment yield in
       New Jersey, J. Soil and Water Cons^rv. 23:142-144.

17.  Wolman, M. G. and A. P. Schick,  1967.  Effects or
       Construction on fluvial sediment, urban and
       suburban areas of Maryland.  Water Resources Kes. 3:4t>l-464

18.  Guy, H. P. and G. E. Ferguson.  1970.  Stream
       sediment:  an environmental problem,  J,
       Soil and Water Conservation 25:7-22.

19.  Vice, R. B. , II. P. Guy, and G. E. Ferguson.   1969.
       Sediment movement in an area of suburban highway
       construction, Scott Run Basin, Fairfax County,
       Virginia, 1961-64.  Geol. Surv, Water-Supply Paper
       1591-E, P,  E1-EU1.

20.  Hathewayr E. S.  1927.  The relation  of  temperature  to
       the quality of food consumed  by  fishes.   Ecology

21.  Fry. F. E. J. and J. S. Hart.   1948.  Cruising  speed of
       goldfish in relation to water temperature,  J,  Fish.
       Res. Bd. Can. 7:169-175.

22,  Brett, J. R., J. E. Shelbourn and  C.  T.  Snoop.   1967.  The
       relation of temperature and food ration  to  the growth
       rate of young sockeye salmon.  In:  Abstracts of Paper
       at the American Fisheries Society 97th Annual
       Meeting.   Toronto, Ontario, Canada.

23.  Black, D. S.  1969.  Keynote address. In:   P. A.
       Krenkel, and F. L. Parker  (ed.). Biological  aspects
       of thermal pollution.  Vanderbilt Univ.  Press,
       Nashville, Tenn.

24.  Wurtz, C. B.  1969.  The effects of heated discharges on
       freshwater benthos.  In: P. A. Krenkel,  and F.  L.
       Parker  (ed.).  Biological aspects of thermal
       pollution.  Vanderbilt Univ.  Press, Nashville,  Tenn.

25.  Mayer, A. G.  1914.  The effects of temperature upon
       tropical marine animals.  Pap. Tortogas  Lab.  o:l-24.

26.  Hedgpeth, J. W. and J. J. Conor.  1969.  Aspects ot  the
       potential  affect of thermal alteration on marine and
       estuarine  benthos.  In:  P. A. Krenkel,  and F. L.
       Parker  (ed.).  Biological Aspects of Thermal  Pollution.
       Vanderbilt Univ. Press, Nashville,  Tenn.

27.  Orton, J, H. 1920.  Sea-temperature, breeding  and
       distribution  in marine animals.   J. Mar. Biol. Ass.
       U. K.  12:339-336.

28.  Gray, J.  1928a.  The growth  of fish.  II. The
       growth  rate of the embryo of  Salmo  .farjLo.  J.
       Exp. Biol. 6:110-124.

29.  Gray, J.  1928b.  The growth  of fish.   III.
       The effect of temperature on  the development
       of the  eggs of Salmo fario.   J.  Exp. Biol.

30.  Patrick, P.  1969.  Some effects ot temperature
       freshwater algae.  In:  P. A. Krenkel, and F.
       L. Parker  (ed. ) .  Biological aspects of thermal
       pollution.  Vanderfcilt Univ. Press, Nashville,

31.  Mrak, E. M.  (Chairman).  1969.  Report of the
       secretary's Commission on pesticides and their
       relationship to environmental health.  Parts I
       and II.  U. S. Department of Health, Education and
       Welfare.  December 1969.

32.  Johnson, O.  1972.  Pesticides '72.  Chemical
       Week 110:34.

33.  Anon.  1972.  Environmental indicators for pesticides,
       Stanford Research Institute.

34.  Ruckelshaus, W. D.  1972.  Consolidated DDT hearings:
       Opinion and order of the Administrator, Environ-
       mental Protection Agency, concerning the registra-
       tions of products containing the insecticide JDT.
       Federal Register 37:13369-14476.

35.  Terrier, L. C. , U. Kiigemagi, A. R. Gerlack ana
       R. L. Borovilka.  1966.  The persistence of
       toxaphene in lake water and its uptake by
       aquatic plants and animals.  J. Agr. Food chem.

36.  Gakstatter, J. L.  and C. M. Weiss.  1965.  Tne
       decay of anticholinesterase activity of organic
       phosphorus insecticides on storage in waters of
       different pH.  Proceedings Second International
       Water Pollution Research Conference, Tokyo.
       1964.  pp. 83-95.

37. Wilkes, F, G. and C. M. Weiss.  1971,  The
      accumulation of DDT by the dragontly nymph,
                      Trans. Amer. Fish. Soc.  100:222-236.
38.   Bridges, W. R., R. J. Kallman and A. K. Andrews.
       1963,  Persistence of DDT and its metabolities
       in a farm pond.  Trans. Amer. Fish. Soc. 92:

39.   Burdick, G. E., E. J. Harris, H. J. Dean, T. M.
       Walker, J. Skea, and D. Colby.  1964.  The
       accumulation of DD1 in lake trout and the effect
       on reproduction.  Trans. Am, Fish. Soc. 93:

40.   Johnson, H. E. and C. Pecor,  1969.  Coho salmon
       mortality and DDT in Lake Michigan.  Trans.
       34th N. A. Wildlife and Nat. Res. Conf.
       pp. 157-166.

41.   Reinert, R. E.  1970.  Pesticide concentrations in
       Great Lakes fish.  Pest. Mont. J. 3:233-240.

42.   Lambou, V. W.  1972.  Problems of mercury emissions
       into the environment or the United States,
       Report to the Working Party on Mercury, Sector
       Group on Unintended Occurrence of Chemicals in
       the Environment, OECD, Environmental Protection

43.   Erl, T. B.  1970.  Methyl mercury poisoning in fish
       and human beings.  Modern Medicine 38:135-141.

43.   Johnels, A,, T. Westermark, W. Berg, P. I.
       Perssonant, B.  Sjostrand.  1967.  Pike  (Esox lucius
       L.) and  some aquatic organisms in Sweden as indicators
       of mercury contamination in the environment.  Oikos

45.  Hannerz, L. 1968.  Experimental investigations on
       the accumulation of mercury in water organisms.
       Fisheries Board of Sweden, Institute of Fresh
       Water Research, Drottningholm, Report No. 48.
       pp. 120-126.

46,  Hasselrot, T. B.  1968.  Report in current field
       investigations  concerning the mercury content in
       fish, bottom sediment, and water.  Fisheries Boara
       of Sweden,  Institute of Fresh water Research,
       Drottningholm,  Report  No. 48.  pp. 102-111.

i»7.  Miettinen, V., E. Blankenstein, K. Kissanen, M.
       Tillander, J. K. Miettinen and M. Valtoueru
       1970.  Preliminary study on the distribution and
       effects of two chemical forms of methyl-mercury
       in pike and rainbow trout.  FAD Technical conference
       on Marine Pollution and its Effect on Living
       Resources and Fishing.  Rome, Italy.  December 9-18.

48.  Hamilton, A.  1971.  Mercury levels in Canadian
       fish.  Paper by E. B. Bligh In:  Mercury in man's
       environment.  Royal Society of Canada; 395
       Wellington St., Ottawa, Ontario.  KIAON U,

U9.  Johnels, A. G.  1971.  Mercury: observed levels
       and their dynamics in the environment.  Results
       from Sweden.  In:  Mercury in man's environment,
       Proc. Symposium February, 1971.  Royal Society
       of Canada, Ottawa.  pp. 62-72.

50.  Unpublished Report, Environmental Protection Agency
       by the National Academy of Sciences.  Water quality
       criteria. Section III, Freshwater Aquatic Life arid
       Wildlife, Final Draft.  July 22, 1972.

51.  Wobeser, G. , N. O. Nielsen and P. H. Dunlap.
       1970.  Mercury concentrations in tissues of
       fish from the Saskatchewan River.  J. Fish.
       Res. 3d. Canada 27:830-83U.

52. Harris, R. C., D. B. White and R. E. Macfarlane.
       1970.  Mercury compounds reduce photosynthesis by
       plankton.  Science 170:736-737.

53. Joensuu, O. I.  1971.  Fossil fuels as a source
       of mercury pollution.  Science 172:1027-1028.

5U. Interdepartmental Task Force on PCB's.  1972.
      Polychlorinated biphenyls and the environment.
      National Technical Information Service.
      Com-72-10U19.  181 pp.

55.  Stalling, D. L.  1971.  Proc. 2nd Annual International
       Congress of Pesticide Chemistry, Tel Aviv, Feb. 22-26,

56.   Lambou, V. and B. Lim.  1970.  Hazards of arsenic in
      the environment, with particular reference to the
      aquatic environment.  Fed Water Qual. Adm. , U. s.
      Dept. of Interior.

57.   Mackenthun, K. M, , W. M, Ingram and R. Forges,
       1964,  Limnological aspects of recreational lakes.
       U.S. Dept. of Health, Education and Welfare, Puolic
       chemical elements in edible aquatic organisms,
       Lawrence Livermore Labcratcry,  UCRL-5056U Rev. 1
       (Also avail, from AEC as TID-U500, US-U8).

6U.   National Academy of Sciences Peport,  1973.
       Radionuclides in foods.  Pub. No. ISBN O-309-0^113-b.

       Health Service, Cincinnati.

58,   Lowman, F. G. , et al.  1970.  Accumulation and
       redistribution of radionuclides ry marine organisms.
       Bureau of Comm. Fish., USDI.  Unpublished.

59.   Dupree, H. K.  Arsenic content of water, plankton,
       soil and fish from ponds treated with sodium arseaate
       Cor weed control.  Proc. Southeastern Assoc. ot Game
       and Fish comm.

60.   Mackenthun, K. M.  1961.  Status of arsenic stuuies.
      Memorandum to the Chairiran  cf Subcommittee on
      Aquatic Nuisance Control, Wisconsin Committee on
      Water Pollution.

61.   Bubeck, R. C. , W. H, Diment, E. L. Deck, A. L.
       Baldwin and S. D. Lipton.  1971.  Runoff or ueicing
       salt:  Effect on Irondequoit Bay, Rochester, New  *ork.
       Science 172:1128-1132.
62.  Bubeck, R. C. , W.  H. Diment  and  A. L.  Deck.
       Some limnological changes  due  to deicing  salt
       runnoff in  Irondequoit  Bay,  Rochester,  N.Y.
       Abstr. Geological society  of American Animal
       Meeting, November 1971,  Washington,  D.  C.

63.  Thompson, S.  E. , C. A.  Burton, D. J.  Quinn  and
       C. N. Yook.  1972.  Concentration  factors of
       chemical elements in  edible  aquatic organisms.
       Lawrence Livermore Laboratory. UCRL-50564  Rev.  1
        (Also avail,  from AEC as TID-4500,  US-48) .

64.  National Academy of Sciences Report   1973.
       Radionuclides in foods.  Pub.  No.  ISBN  0-300-02113-8.