DEVELOPMENT DOCUMENT
for
BEST TECHNOLOGY AVAILABLE
for the
LOCATION, DESIGN, CONSTRUCTION AND
CAPACITY OF COOLING WATER INTAKE STRUCTURES
for
MINIMIZING ADVERSE ENVIRONMENTAL IMPACT
Russell E. Train
Administrator
Andrew W. Breidenbach, Ph.D
Assistant Administrator for
Water and Hazardous Materials
Ernst P. Hall
Acting Director
Effluent Guidelines Division
Devereaux Barnes, P.E.
Project Officer
April, 1976
Effluent Guidelines Division
Office of Water and Hazardous Materials
U.S. Environmental Protection Agency
Washington, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office
• . Washington, D.C. 20402 - Price $3.40
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ABSTRACT
This document presents the findings of an extensive study of
the available technology for the location, design
contruction and capacity of cooling water intake structures
for minimizing adverse environmental impact, in compliance
with and to implement Section 316 (b) of the Federal Water
Pollution Control Act Amendments of 1972.
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CONTENTS
Section
I BACKGROUND
Scope ...
Intake Structure Definition
Cooling Water Use in the United States
Environmental Impacts of Cooling Water Use
Control Strategy for Limiting Impacts on
Aquatic Organisms
Acquisition of Biological Data
II LOCATION
Introduction
Water Sources
Intake Location with Respect to Plant
Intake Location with Respect to the Shoreline
Intake Location with Respect to Water Depth
Intake Location with Respect to the Balance
of the Plant -
Aquatic Environmental Considerations in
Intake Location
General Locational Aspects
III Design
Introduction
Screening Systems Design Considerations
Behavioral Screening Systems
Physical Screening Systems
Fish Handling and Bypass Facilities
Intake Designs
Circulating Water Pumps
IV CONSTRUCTION
Introduction . n
Displacement of Resident Aquatic Organisms
Turbidity Increases
Disposal of Spoil
CAPACITY
Introduction
Fishes
Microbiota
Reduction of Cooling Water Intake Volume
Page
1
2
3
5
10
12
15
15
16
20
23
23
24
24
26
27
27
27
39
62
103
109
142
145
145
145
146
147
149
149
150
152
153
iii
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VI OPERATION AND MAINTENANCE
159
Introduction
Operation
Maintenance
VII COST
Introduction
Cost of Construction of Conventional
Intake Structures
Implementation Costs
Nonwater Quality Impacts
VIII
SUMMARY
Introduction
Adverse Environmental Impacts
Available Technology
Performance Monitoring
Applicability of Intake Structure Technology
IX ACKNOWLEDGMENTS
X REFERENCES*
XI GLOSSARY
APPENDIX A - ENTRAPMENT IMPACT ON MICROBIOTA
APPENDIX B - EVALUATION APPROACH
APPENDIX C - TOPICAL BIBLIOGRAPHY SUPPLIES BY THE
NATIONAL MARINE FISHERIES SERVICE
159
159
161
163
163
164
169
174
175
175
175
175
192
193
195
201
209
215
221
225
*Note: Includes, at the end, a list of documents currently
in preparation which may be useful in the case-by-
case evaluation of th« best available technology
for the location, design, contruction and capacity
of cooling water intake structures for minimizing
adverse environmental impact.
iv
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dumber
II- 1
II-2
II- 3
II- U
III-1
III-2
III-3
in- a
III-5
III- 6
III-7
III-8
III-9
III- TO
III- 11
111-12
III- 13
III- 14
111-15
111-16
FIGURES
Title
Intake Location With Respect to Shoreline
Location of Intake and Outfall - Plant No. 5502
Location of Intake and Outfall - Plant No. 0608
Intakes Drawing From Different Water Levels
Loss of Head Through Traveling Water Screens, '
0.95 cm (3/8") Opening
Intake Velocity and Flow vs Fish Count
Mean Cruising Speed for Under Yearlings and
Yearling Coho Salmon for Four Levels of
Acclimation
Effective Screen Area
Undesirable Intake Well Velocity Profiles
Screen Mesh Size Selection (Based on Length of Fish)
Typical Electric Fish Fence
Air Bubble Screen to Divert Fish from Water Intake
Channel to Test Effectiveness of Air Bubble Screen
at North Carolina Fish Hatchery
Bubble Screen Installation at Plant No. 3608 to '
Repel Fish from Water Intake
Louver Diverter - Schematic
Delta Fish Facility Primary Channel System
Test Flume at Plant No. 0618
Intake Structure - Plant No. 0629 to Divert Fish by
Louver Screens and Return Them Downstream
Fish Elevator for Fish Bypass - Plant No. 0629
Operation of the Velocity Cap
17
21
22
25
29
33
33
35
37
40
42
45
46
'49
52
53
•• 56
'57
58
60
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Ill-17 conventional Vertical Traveling Screen
III-18 Conventional Vertical Traveling Screen
III-19 Traveling Water Screen
111-20 Inclined Plane Screen with Fish Protection
III-21 Fixed (Stationary) Screen (Schematic Only)
111-22 Fixed (Stationary) Screens Detail
III-22a Perforated Pipe Screen (in River Channel)
111-23 Double Entry, Single Exit Vertical Traveling Screen
111-24 Double Entry, Single Exit Vertical Traveling Screen
(Schematic Only)
111-25 Double Entry, Single Exit Vertical Traveling
Screen, Open Water Setting
111-26 Single Entrance, Double Exit Vertical Traveling
Screen
IH-27 Single Entry, Double Exit Vertical Traveling
Screen
111-28 Horizontal Traveling Screen (Schematic Only)
111-29 Mark VII Horizontal Traveling Screen
(Schematic Only)
111-30 Schematic Plan Adaptation of Horizontal Traveling
Screen
III-31 Revolving Drum Screen-Vertical Axis Schematic
/
111-32 Vertical Axis Revolving Drum Screen
III-33 Revolving Drum Screen - Horizontal Axis
111-34 Fish Bypass Structure
111-35 Single Entry Cup Screen
III-36 Double Entry Cup Screen
111-37 screen Structure With Double Entry Cup Screening
64
65
68
70
73
74 '
76
78
79
80
83
84
85
87
89
91
92
94
96
98
99
100
v1
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111-38 Double Entry; Drum Screen Open Water Setting
111-39 Rotating Disc Screen r-
IIJ-HO Fish Basket Collection System
III-iH Modified Vertical Traveling Screen
III-1J2 Shoreline Pump and Screen Structure
111-43 - Conventional Pump and Screen Structure
III-44 Pump and Screen Structure with Skimmer Wall
111-45 Pump and Screen Structure with^Offshore Inlet
lii-«l6 Profile Through Water Intake - Siphon Type
? ' '..'.• ,-•'' ,.'2 '." ? •• *''' ' • '"• "''V' • ' '' : '
IIT-i»7 Approach Channel Intake
III-a8 Screen Location - Channel Intake
III-49 Shoreline Intake
III-50 Flush Mounted Screens - Modified, and
Conventional Screen Settings
III-51 Pump and Screen Structure
111-52 Pump and Screen Structure
111-53 Pier Design Considerations
III-54 Screen Area Velocity Distribution
III-55 Factors Contributing to Poor Flow Distribution
III-56 Pump/Screen Relationships
III-57 Pump and Screen Structure for Low Intake
Velocities
111-58 Effect of Pump Runout
III-59 Pump and Screen Structure with Ice Control
Feature
111-60 Infiltration Bed Intake - Plant No. 1222
101
102
105
108
.111
112
113
114
11.5;
116
118
119
121
122
123
124
126
127
128
130
131
133
135
vll
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Ill-61
111-62
111-63
III-64
V-l
V-2
VII-1
VII-2
VII-3
Infiltration Bed Intake - Plant No. 5309
Perforated Pipe Intake
Radial Well Intake
Angled Conventional Traveling Screens
Pish Count vs. .Intake Flow Volume (Capacity)
Cooling Water Requirements for Fossil and Nuclear
Powerplants
Cost of Intake Systems
Design of Modified Conventional Intake
' ' • ' ' '.
Design of Conventional Intake Modified by
Recommendations
136
138
140
141 '
154
155
166
171
172
vi 11
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TABLES
Number
1-1
1-2
1-3
III-l
III-2
III-3
VII-1
VII-2
VII-3
Title
Intake of Cooling Water by Broad
Categories of Industry
Reports and Predictions of Screen
Kills of Estuarine Species
Reports and Predictions of Inner
Plant Kills of Estuarine Species
Fish Maximum Swimming Speeds
Traveling Water Screen Efficiencies
Electric Screen Applications -
Summary of Design Data
Cost of Traveling Water Screens
Cost of Shoreline Intakes
Cost Analysis - Implementation of
Example Design Requirements
Page
4
7
9
31
38
43
165
168
173
1x
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SECTION I
BACKGROUND
The Federal Water Pollution Control Act Amendents of 1972
state under "Thermal Discharges," Section 316 (b): Any
standard established pursuant to section 301 or section 306
of this Act and applicable to a point source shall require
that the location, design, construction and capacity of
cooling water intake structures reflect the best technology
available for minimizing adverse environmental impact.
Section 306 of the Act requires that effluent standards be
promulgated for point sources in the following categories,
as a minimum:
pulp and paper mills;
paperboard, builders papar and1 toard mills;
meat product and rendering processing;
dairy product processing;
grain mills;
canned and preserved fruits and vegetables processing;
canned and preserved seafood processing;
sugar processing;
textile mills;
cement manufacturing;
feedlots;
electroplating;
organic chemicals manufacturing;
inorganic chemicals manufacturing;
plastic and synthetic materials manufacturing;
soap and detergent manufacturing;
fertilizer manufacturing;
petroleum refining;
iron and steel manufacturing;
nonferrous metals manufacturing;
phosphate manufacturing;
steam electric powerplants;
ferroalloy manufacturing;
leather tanning and finishing;
• glass and asbestos manufacturing;
rubber processing; and
timber products processing.
The requirements of section 316(b) are in contrast to those
of sections 301 and 306, which call for the uniform
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achievement of effluent limitations based on the application
of defined levels of technology.
In addition to the above, operation and maintenance of
cooling water intake structures are important factors which
should be considered in addition to those itemized in
section 316(b) of the Act. consequently, this report^has
been divided into corresponding sections for location,
design, construction, capacity, and operation and
maintenance.
Since the Act specifies cooling water intake structures,
this document is addressed specifically to cooling water
intakes. It is evident, however, that the general technical
discussion could apply to other water intakes; for example,
non-cooling water intakes for industrial, irrigation or
domestic water supply. A major feature of a powerplant
cooling water intake, as distinguished from many others, is
the necessity for essentially continuous operation. Such a
requirement imposes many design criteria that may not be
necessary for other types of intakes. Powerplant intakes
cannot normally be shut down to bypass temporary fish runs,
to clean out silt or to lessen some other seasonal
environmental impact. However, shutdowns may be feasible in
some instances as with a nuclear powerplant scheduling
refueling to coincide with major aquatic biological events
such as predictable critical fish spawning periods, or
seasonal concentrations or migrations of organisms.
One of the goals of Federal Water Pollution Control Act
Amendments of 1972 is to attain water quality which provides
for the protection and propagation of fish, shellfish, and
wildlife. As this goal of upgrading the surface water
quality is achieved, areas currently inhospitable to aquatic
life may be restored. This potential increase in water
quality and resultant changes in aquatic life concentration
should be considered in meeting the requirements of section
316 (b) .
Intake Structure Definition
A cooling water intake structure comprises the total
structure used to direct cooling water from a water body
into the components of the cooling system wherein the
cooling function is designed to take place, provided that
the intended use of the major portion of the water so
directed is to absorb waste heat rejected from the process
or processes employed or from auxilliary operations on its
premises, including air conditioning. As defined above, the
intake structure includes circulating and service water
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pumps where those pumps are located in the
prior to -the heat exchangers or condensers.
cooling system
Cooling water intakes for industrial point sources fall into
three general categories according to the use for which the
water is withdrawn.
Circulating water Intakes - These intakes are for once-
through cooling systems, which are designed to continuously
withdraw the entire circulating water flow. The water is
passed through the condenser and subsequently to a point of
discharge. The typical water usage for which the intake for
powerplants must be designed ranges from about 0.03 to 0.1
cu m/s (500 to 1500 gpm) per Mw.
Makeup Water Intakes - These intakes provide the water to
replace that lost by evaporation, blowdown and drift from
closed cooling systems. The quantity of water required is
commonly 3 to 5% of the circulating water flow. These
intakes are therefore considerably smaller than the cooling
water intakes for once-through systems. Although makeup
quantities are comparatively low, they may be significant in
some cases on an absolute basis.
Service Intakes - These intakes provide the water required
for essential general cooling systems. Here, the water
quantity is small when compared to the circulating water
flow, averaging about 0.002 cu m/s (30 gpm) per Mw of
powerplarit capacity. The special needs of nuclear
powerplants dictate that the intake be quite massive due to
the requirements for redundancy of pumping and screening
equipment and the need for both missile and earthquake
protection.
Often service water systems and circulating water systems
will be contained in separate bays at the same intake. Most
new intakes will have this design. Older powerplants, built
in a series of steps, may have separate intakes for
different functions and may use more than one water source.
Cooling Water Use in the United States
Water withdrawal for cooling by industrial point sources now
amounts to approximately 70 trillion gallons per year.
Steam electric powerplants withdraw approximately 80% of
this, or 60 trillion gallons per year which is roughly 15%
of the total flow of waters in U.S. rivers and streams. The
intake of cooling water by broad categories of industry is
given in Table 1-1. The relative potential significance of
average intake cooling water volumes for establishments
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within the broad categories is shown in the table. However,
the maximum cooling water volumes for individual
establishments will be dependent on factors such as
products, processes employed, size of plant, degree of
recirculation employed in the cooling water system, etc.
Environmental Impacts of Cooling Water Use
The major impacts related to cooling water use are those
affecting the aquatic ecosystem. Serious concerns are with
population effects that reduce harvestable cooling water
intake structures may interfere with the maintenance or
establishment of optimum yields to sport or commercial fish
and shellfish, decrease populations of endangered organisms,
and seriously disrupt sensitive ecosystems.
The aquatic organisms comprising the aquatic ecosystem may
be defined in broad terms as follows:
Benthos - Bottom dwellers are generally small and sessile
(non-swimming) but can include certain large motile species
(able to swim). Location of major populations can be
reasonably well defined and therefore avoided by adoption of
appropriate location. These species can be important food
chain members.
Plankton - Free floating microscopic plants and animals
including fish eggs and larval stages with limited ability
to swim. The location of these species generally are apt to
be rather diffuse throughout the water tody and therefore
the adoption of locational measures would not protect these
species. However, vertical movement cf some species can
occur leading to the aggregation of many plaftkton into
layers. Locational measures* such as withdrawal of water
from hypolimnetic waters, may serve to protect vulnerable
plankton layers. Plankton are also important food chain
organisms.
Nekton - Free swimming organisms (fish). Of major concern
in many cases are egg and larval stages which are 'small and
have limited mobility and therefore generally considered as
plankton. Juvenile fishes may be screenable. Juvenile
fishes may lack swimming or behavioral ability to avoid the
intake. At least in relatively warm waters, adult fish of
most' species "generally" will have the swimming ability to
avoid the intake provided they are stimulated to do so. The
location of spawning and nursery areas and migration paths
are frequently definable and therefore should be reflected
in locational measures.
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One of the first steps that should be taken in determining
the best technology available, for a cooling water intake
structure to minimize adverse environmental impact is the
designation of the critical aquatic organisms to be
protected. This approach has been outlined by the U.S.
Atomic Energy Commission in Reference 24. This approach
requires the determination of the identity and spatial and
temporal distribution of organisms in the area of the
intake. A judgement may then be made as to which of the
organisms are critical aquatic organisms as defined in the
Glossary to this document. The characteristics of these
organisms and the nature of the water body should determine
the environmental design of the intake structure. The
control strategy for minimizing environmental impact may be
different for planktonic species than for nektonic species
as discussed below.
Damage to aquatic organisms occurs by either entrapping or
impinging larger organisms against the outer parts of the
cooling water intake structure or by entraining small
organisms in the cooling water as it is pumped through the
innner plant.
Entrapment (often called impingement) of nektonic species
can be caused by hydraulic forces in the intake stream prior
to its flow through screens, etc. In general, entrapment
Will be lethal for most species due to starvation and
exhaustion in the screen well, asphyxiation when forced
against a screen by velocity forces which prevent proper
gill movement, descaling by screen wash sprays and by
asphyxiation due to removal from water for prolonged periods
of time. Table 1-2 taken from Reference 35 presents some
reports and predictions of screen kills of estuarine
species.
Inner-plant or entrainment damage to organisms may result
from the passage of relatively small benthic, planktonic and
nektonic forms through the condenser cooling system.
Mortality of these organisms can occur from one or more of
the following causes:
- physical impact in the pump and condenser tubing
- pressure changes caused by diversion of the cooling water
into the plant or by the hydraulic effects of the condensers
- thermal shock in the condenser and discharge tunnel
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toxemia induced by antifouling agents such as
Table 1-3 taken from Reference 35 presents some reports and
predictions cf inner plant kills of estuarine species.
Reference 39 summarizes the available data on relative
mortality of entrainable marine organisms due to passage
through powerplant cooling systems.
Damage to aquatic organisms may result from damage
aquatic habitat, examples of which are given below:
to the
Natural temperature regimes and distribution
patterns of a water body could be disrupted by
circulation of large volumes during withdrawal of
cooling water.
Freshwater inflow to estuaries may be diminished by
withdrawals for powerplant cooling which are
subsequently discharged to the open ocean or
another drainage system. The reverse may occur
when saline waters are taken into the plant and
discharged into freshwater zones.
Normal salinity distributions within estuarine
areas may be altered by currents and mixing
resulting from cooling water pumping with resultant
damage to key habitat for organisms.
Clean water areas may be contaminated by
introduction or redistribution of polluted water
withdrawn from .another area. This particular
problem can be severe if an intake is located in an
area with low biological populations, if the low
populations are the result o£ water pollution.
Seemingly, logical placement of the intake there
because of few organisms would result in withdrawal
of much polluted water which could damage areas of
clean habitat.
Intake or discharge structures, including dikes or
dredged channels, may prevent a normal circulation
of water or bar migration of organisms.
Discharge plumes may interfere with sediment
transport along the shore and affect the deposition
of sand and sediments in the discharge or nearby
area, resulting in shore erosion of some degree of
beach starvation.
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Estimated from EPA's
sampling techniques.
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July 2; fish mangled.
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showed all fish died.
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Other Environmental Impacts
environmental concern.
significant external sound levels.
from agitation of soils35.
control strategy for Limiting Impacts on Ac
being effectively screened even on a fine mesh screen.
10
-------
After considering location, another method to control
entrainment effects where benthic and planktonic organisms
are identified as important organisms to be protected would
be to limit the capacity (volume of cooling water withdrawn
from a source) to a small percentage of the makeup water to
that source. Peterson *« has estimated the thermal
capacity of some of the Nation's larger waterways. This
work could be expanded to establish relationships between
intake capacity (volume), stream flow and aquatic organisms.
Where existing stations exceed the recommended volume to
protect aquatic organisms, steps could be taken to reduce
the intake volume. Implicit in this approach is the
assumption that the impact of entrainment effects on a
waterbody is directly related to the volume of intake flow ,
i.e., the lower the flow, the lower will be the damage to
planktonic and benthic species. This assumption should be
evaluated for each intake structure rather than considered
an ubiquitous assumption.
Another approach, outside the scope of this document, would
be to design the remainder of the cooling water system to
minimize the effect on entrained organisms. This approach
involves limiting the temperature, pressure, chemicals
added, and time of exposure of the aquatic species to levels
that will insure satisfactory survival of important
organisms. A considerable amount of research has been done
on the subject of survival of entrained organisms after
passage through condenser cooling water systems. The
results of these studies are often conflicting. The
National Academy of Engineering,3* recommended that the
condenser system be designed according to the following
formula:
t ( T) < 2000
t = exposure time (seconds) at elevated temperature
T = temperature rise (°C) across the condenser
This formula implies that higher temperature rises could be
tolerated by most species if the exposure time were kept to
a minimum. It is believed that the experimental data upon
which this formula is based were limited and therefore
caution is suggested in the application of this formula.
It is noted that this approach is directed at the remainder
of the condenser cooling system and is not applicable to
intake structures.
11
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Reference 3U, prepared by the National Academy of
Engineering, Committee on Power Plant Siting, also tabulates
for various characteristics (temperature, pressure,
turbulence, light intensity changes, mechanical, volume,
density, circulation, salinity, chemical, biological, etc.)
the short-term and long-term alternatives for the siting and
design of powerplants corresponding to aguatic systems in
general and for oceanic, esturarine, riverine, lake and
reservoir zones.
Acquisition of Biological Data
Probably the most widely ignored aspect of data collection
for intake structure design is the biological data on the
critical aguatic organisms to be protected. Most of the
data collected for intake structure design concerns the
hydrological information relative to the water source. This
information consists of data on water currents,
sedimentation, water surface elevations and water guality.
In general, relatively little data on the biological
organisms is collected. The design of intakes should be
based on protection of the critical aquatic or other
organisms as well as the traditional design considerations
of adeguate flows, temperatures and debris removal. In
addition, it has been noted that the design criteria for the
protection of the environment will be significantly
different for different species. it is therefore necessary
that in each case sufficient data be made available on the
biological community to be protected, including predictive
studies where needed.
The data that should be provided depends upon the severity
of the problem. For plants withdrawing water from sensitive
water bodies the minimum data should consist of the
following:
- The identification of the major aguatic or other species
in the water source. This should include estimates of
population densities for each species identified, preferably
over several generations or seasons of the population to
account for expectable seasonal variations.
- The temporal and spatial distribution of the identified
species with particular emphasis on the location of spawning
grounds, migratory passageway, nursery area, shellfish beds,
etc.
- Data on source water temperatures for the full year.
12
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Documentation of fish swimming capabilities for the
species identified over the temperature ranges anticipated
and under test conditions that simulate as closely as
possible the conditions at the intake.
Location of the intake with respect to the seasonal and
diurnal spatial distribution of the identified aquatic
species.
The criteria for the biological survey for the development
of this data are not presented here. There are several
excellent publications on the techniques to be used in
conducting biological surveys. These techniques are given
in cites (a) , (c) , (d) , (e) , and (f) , page 11 of the 316 (a)
guidance document. The EPA also plans to publish
guidelines for the conduct of biological surveys under
section 316 (b). The techniques will differ both with the
type of organism and the source of water.
As noted above, the type and extent of the biological data
required in each case will be determined by the actual or
anticipated severity of the adverse environmental impact.
Since adverse environmental impacts will vary from case to
case, it is not expected that each case will require the
same detail of information.
13
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-------
SECTION II
LOCATION
Introduction
This section is concerned primarily with intake location,
although it will become evident that intake location is
closely associated with the other factors.
"Intake structure" as previously defined, means the entire
intake facility which may consist of one or more elements
including an inlet structure (the point of water entrance),
closed conduits and open channels, a pump structure or a
combined screen and pump structure. "Location" refers to
both the horizontal and vertical placement of the intake
structure with respect to the local above-water and under-
water topography. This section attempts to answer such
questions as: where is the intake to be located with
respect to the shoreline, navigation channels, wetlands,
discharge structures, and areas of important biological
activity? Also, from what depths is the water to be drawn?
The discussion is concerned with three locational aspects of
the intake's relation to the environment:
The operation of the intake insofar as its location
affects operational characteristics.
Construction activities such as dredging, excavation and
backfill for channels, inlet conduits, inlet structures,
and pump and screen structures. The environmental
influence may be considerable, but it should be
temporary if suitably controlled.
Aesthetics, the appearance of the intake facility and
its relationship to the surroundings. Both the design
and the location of one or more elements of the intake
facility may be dictated in part by aesthetic
considerations.
The most important locational factor influencing the intake
design is the nature of the water source from which the
supply is taken.
Other locational factors which must be considered are the
location of the intake structure with respect to the
15
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discharge structure, the vertical location of the intake,
the location of the intake with respect to the balance of
the plant and the avoidance of areas of important biological
activity. Depending on the nature of the water body and
sensitivity of the biofa, the intake may be located off-
shore, flush with the shoreline or inland with an approach
channel as shown in Figure II-l. The reasons for selection
of a particular orientation with respect to the shoreline
are both to provide the required volume of cooling water and
to minimize withdrawal from biologically sensitive areas.
Water Sources
Fresh water Rivers
Rivers normally are characterized by unidirectional flow,
which eases the intake design problem. Most large rivers
will generally possess sufficient resistance to
recirculation due to the velocity gradient to permit the
siting of both intake and discharge at the shoreline.
Recirculation might present a problem at extremely low river
flows. The base of the river intake is generally set at the
lowest river bed elevation, however, it should be set above
significant silt accumulations to prevent silt deposition in
the intake. Different locations in streams have different
susceptibilities to silting. The inner sides of river bends
are more susceptible to silting than the outer sides. The
top of the intake is usually set for high flow and flood
conditions. The pump operating deck is usually placed
several feet above the flood crest level. Large water level
and flow variations can make river intake structures
correspondingly elevated above normal water levels.
Ice flows and debris loading are also significant for many
river locations as are the maintenance of navigation
passages. Rivers will usually possess minimum temperature
stratification compared to lakes because of greater
vertical and horizontal mixing.
Diversion structures at the shoreline can employ the
currents of the river to carry fish downstream and thus
avoid entrapment at the intake. However, such structures
covtld trap upstream migrants, leading them to the intake.
Small Fresh Water Lakes and Reservoirs
16
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WATER
SOURCE
v
TO POWER PLANT
WATER
SOURCE
/\
INLET FLUSH WITH SHORELINE
IT o
L.J.
TO POWER PLANT
f I 4
OFFSHORE INLET
WATER X_
SOURCE
r
_fct,
,. CANAL
1 'B8"
Top
.Ly?-
"S" -rf b TO
^/ ' • POWER PLANT
OPEN CANAL TO INLET
FIGURE 11-1 INTAKE LOCATION WITH RESPECT TO SHORELINE
17
-------
The most significant difference between lakes and rivers,
apart from velocity structure, is the fact that the former
are often stratified with respect to temperature. The
thermal stratification of lakes is a complex phenomenon.
The heat balance of a lake depends on ambient air
temperature, wind speeds, the topography of the lake bottom
and flows into and out of the lake. It is clear that a
large withdrawal or discharge of cooling water can
significantly affect thermal stratification. The zone of
cold water at the bottom of the lake is called the
hypolimnion. The water in the hypolimnion is relatively low
in dissolved oxygen and often high in nutrients (nitrates,
phosphates).
Hypolimnetic waters may have a lower pH than the epilimnion
waters, and on some occasions may accumulate significant
amounts of materials capable of causing fish kills if pumped
to the surface where the fish are located.
Lying above the hypolimnion of a stratified lake is a zone
of distinctly warmer water, the epilimnion. The significant
features of this zone are that it is the area from which
evaporation takes place; it is the region into and out of
which the natural stream courses flow; it washes the shore-
line or littoral zone which is a region of highly abundant
life and it supports considerable populations of life
throughout its extent. The water in the epilimnion is
usually high in dissolved oxygen. Artificial reservoirs may
have poorly defined littoral zones because of drawdown
procedures. Under some conditions this may not be true.
Additional information regarding the productivity of
littoral zones of reservoirs may be obtained from the U.S.
Fish and Wildlife 'Reservoir Research Center, at
Fayetteville, Arkansas. While the littoral zone of a
reservoir may be attractive for an intake location because
it does not support as much life, it is of little use to the
intake designer who will find a shoreline intake too often
high and dry.
Within the epilimnion is the uppermost zone which is called
the photic zone. The productivity of this zone is a
function of the degree of penetration of sunlight and the
presence of necessary nutrients. As little water as
possible should be taken from the epilimnion and the
absolute minimum from the photic zone. Off-shore intakes
with multiple entrance ports appear to have great
application in stratified lakes.
Lakes generally do not have the pronounced flushing currents
that many rivers have. Therefore, the possibility of re-
18
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circulation becomes more significant. In addition, there is
no assistance by current flushing to wash debris and fish
past the intake. , ... -1
Wind forces provide most of the water level variation, and
wave protection is an important design consideration in
intake structures for lakes. Commercial navigation is
generally not as important a factor as in rivers, since
shoreline and dams prevent access to most lakes. However,
recreational use is more prevalent on lakes than in many
rivers.
Estuaries
A number of factors combine to make intake design and
location selection for estuaries the most difficult of all
water source types. Flow is two directional which
complicates the design of many screening systems. Similar
to lakes, most estuaries exhibit stratification, although
stratification in estuaries is generally less stable than in
lakes. Water density depends on both water temperature and
salinity. Volumetric fluctuations are greater due to the
periodic influx of sea water. The salt content varies with
tidal cycles. Estuaries are often stratified with respect
to salt content, with fresh water tending to ride above the
salt. In areas where cooling water discharge effects are
present, density stratification in potential intake areas is
further complicated by the differing buoyancies of warm and
cool water, and fresh and salt water.
Estuaries are major spawning areas for both ocean fish and
shellfish, with wide seasonal variations of biologic
activity. The presence of current reversals can create
severe recirculation problems. Because of the high salt
content and tidal variations which create periods of high
and low water, corrosion becomes much more significant in
intakes designed for estuaries.
Oceans and Large Lakes
An important consideration in the design of intakes on
oceans and large lakes is the storm wave protection system.
Wave damping upstream of the screens is required. There may
be heavy sediment load in the surf area. Other factors to
be considered are littoral drift and shoreline instability.
The littoral zone is highly productive biologically,
although generally not as productive as are estuaries.
Thermal stratification exists but is not as stable as that
in small lakes because of the higher degree of vertical
19
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turbulence. Major migration routes and spawning sites for
pelagic species and shellfish areas should be identified and
avoided in locating cooling water intake structures.
Navigation passageways should also be considered.
Intake Location with Respect to Plant Discharge
From the point of view of plant cooling water efficiency
requirements the use of the coolest available water is
desirable. Accordingly, considerable attention normally has
been given to avoiding the inadvertent recirculation of warm
water discharge back into the intake. From a fish
attraction standpoint, the avoidance of recirculation is
also advantageous. Long experience has shown that many
species of fish tend to congregate in warm water areas,
especially in the cooler seasons of the year. In at least
one major nuclear plant, a small amount of recirculation
attracted fish to the intake area in winter. The fish thus
attracted were also lethargic due to the low winter
temperatures of the water and tended to be carried into the
screens. \
The technical aspect of the avoidance of recirculation is a
subject beyond the scope of this study. The subject would
involve an analysis of the existing water currents, the
stratification of the warm water and the dilution and
dispersion characteristics of the discharge structure.
There are a number of ways in which recirculation can be
avoided. Two of these are shown in Figures II-2 and II-3.
Figure II-2 shows the location of two intakes and discharges
at plant no. 5502. The method used at this plant to prevent
recirculation is to locate the intake a considerable
distance off-shore and locate the discharge at the
shoreline. Figure II-3 shows the location of the intake and
outfall for a hypothetical plant. This plant avoids
recirculation by withdrawing water from one body of water
and discharging to another body of water. This type of
separate discharge may have other environmental impacts due
to differences in constituents or transfer of organisms from
one habitat to another. Other ways of avoiding
recirculation are to separate intake and outfall by a
sufficient distance, the construction of a physical barrier
between the intake and outfall, and the excavation of a
channel for the intake or outfall or both. Prevention of
recirculation also requires adequate vertical separation of
intake and discharge. This is important in a stratified
water body such as a lake. Vertical separations of between
20 to 60 feet have been used at some locations. Isolating
20
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LOCATION OF INTAKE AND OUTFALL - PLANT NO. 5502
FIGURE
21
-------
DISCHARGE CONDUIT
INTAKE CONDUIT
350 FT.
INTAKE
LOCATION OF INTAKE AND OUTFALL - Plant No. 0608
FIGURE II-3
22
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intakes and discharges by building strong physical barriers
between them cr the excavation of a major channel for the
intake or outfall, or both, may not be the best technology.
An example of such construction is the Crystal River plant
in Florida, which has a dike several miles long projecting
into the Gulf of Mexico. While it prevents recirculation,
it also prevents the natural circulation for many miles on
the coast and interferes with migration of aguatic
organisms. The major intake and navigation canal bordering
this dike may at times be instrumental in leading organisms
into the intake.50
From the standpoint of the effect of recirculation on fish
attraction, it should be noted that proper location of the
inlet point both with regard to site location and water
depth is an important element to be considered.
Intake Location with Respect to the Shoreline
As mentioned above and shown in Figure II-l, there are three
basic orientations of intakes with respect to the shoreline.
The difference among them is the relative position of the
water inlet with respect to the shoreline. The intake at
the top of the figure has the inlet flush with the
shoreline. This intake may also be called a shoreline
intake or a bankside intake. The middle intake has the
inlet located offshore with a conduit leading to the shore.
The offshore inlet may be only a pipe opening as shown, or
may include water screening facilities and pumps. The third
type of intake uses an open channel inlet (generally
excavated) leading to an inland water screening facility.
This , latter type of intake may also be referred to as an
onshore intake.
Each of these different intake orientations may be used for
any type of water source (river, lake, estuary, or ocean).
The flush inlet and the offshore inlet offer alternate means
for withdrawing water in areas where the aquatic population
may be minimal. The third scheme (open channel) may have
desirable attributes from an aesthetic point of view, but
often creates a problem due to fish which collect in open
channels. This aspect will be discussed in the design
'section of this report.
Intake Location with Respect to Water Depth
From the biological standpoint, the depth at which water is
taken can be a major factor regarding damage to aguatic
23
-------
organisms. In some locations, it may be desirable to draw
surface water only as shown in Part A of Figure II-i*. At
other locations, it may be better to draw deep water as
shown in Parts B and C of the same figure. A complicating
factor is that the desirable water supply depth may vary
seasonally or even diurnally, making multilevel intakes
environmentally attractive. A typical multilevel intake is
shown in Part D of the figure. For water sources where the
biologic community is extremely sensitive to intake
currents, a deep intake of the infiltration type might be
best as shown in Part E of the figure.
Intake Location with Respect to the Balance of the Plant
Some organisms will undergo damage in the passage from the
intake screens to the condensers and on the return between
the condenser and the natural environment. The extent of
the damage is related to the temperature and pressure
changes and the times of travel involved. Since the times
of travel are related to the distances between the intake,
the plant and the outfall, it would be desirable, in cases
where incremental damage due to this effect would be
significant, to locate the intake and/or outfall as close to
the plant as possible. Due to the fact that the temperature
of the water containing the entrained organisms increases as
this water passes through the condenser and remains at this
higher temperature until the water is discharged to the
natural environment, this consideration applies even more to
the location of the outfall with respect to the plant.
Aquatic Environmental Considerations in Intake Location
The location of the intake should reflect the knowledge of
the various members of the aquatic community. The location
should be selected to minimize the impact of the intake on
the critical aguatic organisms. In general, the
considerations leading to the identification of a suitable
intake location should include the following:
avoidance of important spawning areas, juvenile rearing
areas, fish migration paths, shellfish beds or any
location where field investigations have revealed a
particular concentration of aquatic life.
selection of a depth of water where aquatic life is
minimal. This depth may change seasonally or diurnally.
selection of a location with respect to the river or
tidal current where a strong current can assist in
24
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SURFACE INTAKE
(A)
G:
c
DEEP INTAKE
(B)
DEEP INTAKE
(C)
2
t \ A A
MULTI LEVEL INTAKE
(D)
DEEP INTAKE (INFILTRATION)
(E)
FIGURE 11-4 INTAKES DRAWING FROM DIFFERENT WATER LEVELS
25
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carrying aquatic life past the inlet area or past the
face of screens (if the flush mounted type of setting is
used, for example) .
selection of a location suited to the proper technical
functioning of the particular screening system to be
used. For example, louver and horizontal screen
installations have limiting requirements relative to
water level variations and intake approach channel
configurations which will influence their locations with
respect to the source of water.
The application of the above presupposes that sufficient
biological investigation has been conducted to establish
sensitive areas and critical aquatic organisms. The
previous section of the report outlined the type of data
required in the procedure for biological data gathering.
These data are essential for proper intake location.
Furthermore, when returning bypassed fish and other
organisms, they should be delivered to a hospitable
situation.
General Locational Aspects
Reference 31, prepared by the National Academy of
Engineering Committee on Powerplant Siting, contains a body
of material which may be useful in the further development
of solutions to powerplant siting questions. Considerations
relevant to impacts on aquatic life of intake screens,
inner-plant passage and other factors are presented
corresponding to oceanic, estuarine, riverine, lake and
reservoir zones.
26
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SECTION III
DESIGN
Intro duct ion
This section of the report describes the various components
which comprise an. intake structure. |The components include
screening devices, trash racks, pumps and fish handling and
bypass equipment. This type of presentation is utilized to
facilitate an understanding of the function and
configuration of the individual components. Following this,
the description of components is assembled into complete
descriptions of intake designs, with considerations
developed for each type of design. The section is presented
in parts as follows:
Screening Systems Design Considerations
- Behavorial Screening Systems
Physical Screening Systems
Pumps
- Fish Handling and Bypass Facilities
- Intake Designs
This discussion of intake and screen facilities is
relatively comprehensive but is not intended to be all
inclusive of designs both in service and under development.
There is no intent to restrict designers to the
consideration of devices specifically covered in this
document. .
Screening Systems Design Considerations
By far the most important design consideration for screening
systems at intake structures of a given capacity are the
velocity characteristics involved, although bypass and
recovery systems can be used in some cases to offset
disadvantageous velocity characteristics. Intake velocities
are usually measured in several ways as follows:
27
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Approach Velocity - Velocity in the
measured upstream of the screen face.
screen channel
Net Screen Velocity - Velocity through the screen
itself. This velocity is always higher than the
approach velocity because the net open area is reduced
by the screen mesh, screen support structure and debris
clogging.
At Entrance Restrictions - velocity at restricted areas
such as under or over walls at the intake entrance.
Velocity considerations should be fcased on the approach
velocity since the net screen velocity is constantly
changing with debris loading in the waterway. Another
important design consideration is the selection of the
screen mesh size. This should be based on both fish size
and debris loading considerations.
Other environmental factors to be considered in designing
intake water screens can affect the configuration of the
intake structure itself. These factors include proper
location of screens to avoid zones of entrapment, and good
hydraulic design to insure uniform flow over the entire
screen face. This latter element is influenced by the de-
sign of the hydraulic passages both upstream and downstream
of the screen. The downstream design also includes the
location of pumps.
Approach Velocities
Most existing water screens at intake structures have been
designed solely for debris removal. The design criterion is
usually that a relatively low head loss *be maintained
across the screen at the lowest water level anticipated.
Typical velocities through the screen mesh fall in the range
of 0.61 to 0.76 meters per second (2 to 3 feet per second)
which would correlate to screen approach velocities in the
.range of about 0.24 to 0.34 mps. (0.8 to 1.1 fps) or
higher.
Hydraulic head loss is an important design consideration
since it controls the pressure loading on all moving parts
Of the screen. Thus, loweringthehead loss across the
screen lowers the operating cost of the screen and increases
• screen life. Head loss increases as the square of the
approach velocity, and becomes even greater as debris
clogging causes increased turbulance across the screen and
reduces the net screen area. The effect of these factors on
head loss is shown in Figure III-l. This plot is based on
28
-------
(FEET/SEC)
2.14
0.304 0.606 0.912 1.22
DESIGN VELOCITY IN METERS/SEC
ui
01
u.
1.52.
FIGURE 111-1 LOSS OF HEAD THROUGH TRAVELING WATER SCREENS
0.95 CM (3/8") OPENING
29
-------
0.95 cm (3/8") galvanized wire mesh. Screen velocity, which
is related to screen opening, is also important because of
its possible impact on impinged organisms.
Many intermittently operated traveling screens are designed
to be operated under a maximum head loss of 1.5 meters (5
ft) . Some traveling screens operate continuously at a lower
head loss, generally 0.3 to 0.6 meters (1 to 2 ft). Some
traveling screens are rotated once every 4 to 8 hours for 5
to 10 minutes for low head losses, rotated more often for
incrementally higher head losses, and run continuously at
high speed for the highest head losses. Many powerplant
intakes include a pump trip-out to shut off the circulating
water pumps automatically when .the head loss exceeds 1.5
meters (5 ft) or when the downstream water level drops to
some predetermined level. In the absence of such a trip-out
provision, head differential across the screen would rapidly
increase to the point of screen collapse and possible damage
to the pumps.
Another important design feature of traveling water screens
is the rate of screen travel when operating. Screens that
are not intended for continuous operation are designed for a
single operating speed of 3.1 meters per minute (10 fpm) ,
although speeds as low as 0.6 meters per minute (2 fpm) and
as high as 6.1 meters per minute (20 fpm) have been used at
particular locations. For continuous screen operation
(rarely used at powerplant intakes) or for use under varying
flow conditions, two speed screens are used, 0.8 and 3.1 mps
(2.5 and 10 fps) being the usual speeds. Screens are
generally operated once per shift and are rotated
automatically in response to water level differential across
the screen face. The importance of considering operational
frequency and screen speed characteristics in minimizing
impingement effects will be covered in the section on
operation and maintenance of intake structures.
Much of the reported research would indicate that consid-
erably lower approach velocities than the 0.2 to 0.34 mps
(0.8 to 1.1 fps) range shown above may be required to
protect against . impingement of certain species of fish.
Table III-l provides a tabulation of fish swimming
capability of various species taken from Reference 21. It
is included as a sample of the type of information that is
available or may be obtained, with the exception that it is
not indicated whether the velocities are sustained, burst,
or cruising speeds. This type of distinction may be
important to intake velocity considerations in specific
cases. The table shows that fish swimming ability is a
function of both fish size and the ambient water
30
-------
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temperature. An inspection of the lower levels of swimming
capability within each species shows that approach
velocities of considerably less than 0.31 mps (1 fps) may be
desirable. It may be important that cruising, sustaining,
and darting swimming speeds be considered before
establishing approach velocity needs.
Figure III-2 shows the results of additional studies of the
impact of volume flow and approach velocities on fish
impingement. These studies were conducted at a major
nuclear plant in the Northeast and reported in Reference 8
g. The involved species were the white perch and striped
bass. It is important to note that this study was not done
during the critical winter months when fish swimming ability
would be at its lowest. The figure appears to indicate a
marked increase in impingement above intake velocities of
approximately 0.2 mps (0.8 fps) .
Screen kill rate is often claimed to be a function of the
velocity of flow of the cooling water into the intake
structure, the higher fluid momentum forces causing greater
entrapment of fish. This is probably true to a certain
extent but volume also plays an important role. Plotting
the data of Figure III-2 as "fish count per unit of intake
flow volume" versus the "intake current velocity" , to
separate velocity effects from, intake flow volume (capacity)
effects, shows no apparent correlation with velocity.
Therefore, intake velocity itself may not be a significant
factor compared to intake flow volume.
Figure III-3 shows the results of another study which was
reported in Reference 24. This figure shows the swimming
ability of young salmon. The effects of both size and tem-
perature on swimming ability are significant. Note,
however, that the mean cruising speed for all sizes is a
relatively low 0.2 mps (0.5 fps) for the colder winter
temperatures. Oxygen level, as well as temperature, may be
a determining factor in fish-swimming ability. The
selection of the design approach velocity should
conservatively reflect the degree to which the conditions of
the laboratory fish-swimming tests correspond to the
conditions of the intake considering that the natural
behavior of the fish and their escape response are based
upon a complexity of factorsi Futhermore the magnitude of
the horizontal velocity of the stream at the intake will
influence the ability of the fish to avoid its intake screen
and thus affect the influence of the approach velocity in
guiding aquatic organisms into the cooling water structure.
A further significant parameter could be the current at the
screen itself which would determine the ease of escape of a
32
-------
S on '0-2 0.4
N 80
«J
2
CC
o
UJ 60
i 2
•J ui
0 CC
UI W
^ DC
< UI
1- "*• 40
21-
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oc S
uJ £2
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(FEET/SEC)
0.6 0.8
*v
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RESULTS OF DATA OBTAINED SPRING, 1966
O*
1.0 1.2 1.4
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_
" ° *
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CIRCLES REPRESENT DATA OBTAINED FALL, 1965 w (|
o
« -
Note: The use of points on the graph does not necessarily O
reflect the precision of the data displayed. M
i *
\
' 0 .
^ oioT 0.061 0.122
AVERAGE
FIGURE III -2
0 «
UI
CO
u
Q30
UI
UI
« MEAN SLOPE -
i 15 . ^^-'-'
)
1
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0.183 0.244 0.305 0.366 0.426
INTAKE CURRENT VELOCITY IN METERS/SEC
INTAKE FLOW AND VELOCITY VS FISH COUNT
. 20°C^^-^
§ COHO UNDER YEARLINGS
oc
0 r, ... .-I. .
i • t
1.0
^^
-------
fish once impinged and also the extent of damage to the fish
while impinged.
Experience at existing intakes or from controlled testing
has resulted in the following general notions for particular
types of intake systems:
Systems employing a guidance principle such as louvers
may have highest guidance efficiency at relatively high
approach velocities, generally in the range of 1 to 3
ft/sec.
Intakes employing a fish recovery, and handling system,
such as vertical traveling screens with scoops for
lifting fish, may have their highest survival rate when
there is a relatively high approach velocity. Fish tend
to swim against a low approach velocity until they are
fatigued and, therefore, when they are eventually picked
up in the recovery device they are more susceptible to
the stress imposed by handling. At relatively high
velocities the fish are carried in the recovery system
and picked up before they are fatigued.
Low approach velocities may be more desirable for intake
systems which rely on sustained swimming .capability of
fish to avoid entrapment.
An efficient, properly-designed or naturally-occurring
bypass system, moving fish quickly past and out of the
influence of the screens, may permit higher approach
velocities.
Effective Screen length and Uniform Velocities
It is important to determine the effective dimension of
screen below the water line to be used in calculating the
approach velocity. Not all of the screen length below the
water line contributes effectively to screening. The
effective length of screen is influenced by both the
hydraulic design of the intake and by bottom effects related
to the screen boot, boot plate, etc. Another important
consideration in determining the effective screen length is
the effect of upstream protrusions, particularly the effect
of walls installed to select intake waters.from the top or
bottom layers of the water body. The effect of walls on
the effective screen area is shown in Figure III-4. The
illustration shows a wall installed to limit draft to the
lower levels of the water body. The wall limits the flow
through the screen area to a relatively narrow band at the
34
-------
TRAVELING
SCREEN
i CURTAIN WALL FISH
SUCTION PUMP
f AREA OF
1 SCREEN
ACTUALLY
EFFECTIVE
FIGURE IH-4 EFFECTIVE SCREEN AREA
35
-------
bottom of the screen. If walls are installed, only the
effective screen area should be used to determine the
approach velocity. Walls can be undesirable when they
create dead spaces where fish can accumulate and from which
they may not be able to escape.
Another important design consideration is the uniformity of
velocities across the full face of the screen. An example
of poor hydraulic design is shown in Figure III-5. The
sketch shows large variations in channel velocities which
greatly reduce the effectiveness of the screen. To elimi-
nate these undesirable conditions, the relative locations of
pumps, screens and any upstream protrusions should be
carefully studied. The standards of the Hydraulic Institute
recommend screen to pump distances. However, these are
based on pump performance criteria only. Any radical de-
parture from standard intake design should be modeled to
establish the actual screen velocity and the extent of any
localized variations.
Selection of Screen Mesh Size
The selection of screen mesh size is generally based on
removal of trash that could clog condenser tubes. A
generally accepted rule of thumb for selecting the screen
mesh size is that the clear openings in the screen should be
limited to about half the diameter of the heat exchanger
tubes. The powerplant industry has become fairly
standardized on a 0.95 cm (3/8") mesh size (eguivalent to
1.9 cm (3/4") ID tubes) even though,different size condenser
tubes are used in other condenser designs.
The effect of screen mesh size on the performance of screens
is quite significant as shown in Table III-2. The data were
supplied by a leading screen manufacturer. The table shows
that the screen efficiencies (ratio of net open areas of the
screen to total channel area) decrease rapidly as the mesh
size decreases. The table also shows that using alloy
metals in place of galvanized metals will increase the
screen efficiency as will the use of wider and deeper
screens. Alloy metals are generally used to inhibit
corrosion in high salinity waters, such as experienced in
ocean or estuarine intakes, or in other corrosive waters.
PVC screen mesh is also used. The effective area is less
than for wire mesh for a given screen size. Thus if mesh
velocity is a limiting criteria (rather than screen approach
velocity) the total screen area must be greater.
36
-------
NOTES:
1. VELOCITIES SHOWN IN METERS/SEC
2, MEASUREMENT MADE BETWEEN DEICING LOOP PIPE AND BAR RACKS
IN MARCH 1970
3. MEASUREMENT MADE AT A WATER FLOW RATE
60% OF FULL CAPABILITY
FIGURE Hl-5 UNDESIRABLE INTAKE WELL VELOCITY PROFILES
37
-------
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38
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some work has been done toward establishing screen mesh size
as a function of the size of fish to be screened. Reference
24 reports the following empirically derived relationships:
M= 0.04 (L-1.35)F; 5
-------
0.0
7.5
1 5.0
X
v>
u.
u.
O
X
X3
UJ
~H 2.5
0.0
0.0
0.1
M = (INCHES)
0.2
0.3
£ CHINOOK SALMON
O STRIPED BASS
0.25 0.50 0.75
M = CLEAR OPENING (CM)
0.4
3.0
2.0
CO
in
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1.0
0.0
1.0
FIGURE III-6 SCREEN MESH SIZE SELECTION
(BASED ON LENGTH OF FISH)
40
-------
such as a predator. For these reasons, most behavioral
systems have not demonstrated consistent high level
performance.
In addition, all behavioral systems require a passageway to
allow the fish to move away from the stimulus. The location
and configuration of the required passageway is often more
difficult to develop than the behavioral barrier itself.
The following discussion traces the development of several
of the behavioral screens in an attempt to establish their
applicability in intake design.
Electric Screens
The basis of the electric screen approach is described in
Reference 18 and is shown in Figure III-7. Immersed
electrodes and a ground wire are used to set up an electric
field which repels fish swimming into it. The important
design parameters in electric screening are the spacing of
electrodes, the separation between rows of electrodes, the
voltage applied to the system, the pulse frequency, the
pulse duration, and the electrical conductivity of the
water. Typical design parameters for both test systems and
full-scale systems are shown in Table III-3. The data for
this table were taken from Reference 13. Most of the test
systems established by the former U. S. Fish and Wildlife
Service (now the National Marine Fisheries Service) were
applied to repel (and divert) upstream migrating fish (adult
fish). In most waters, but particularly in brine or salt
waters, conductivity can vary, widely with stream flows,
tidal changes and storms, thus creating a need for proper
adjustment of the electric screens to maintain the electric
potentials desired. :
Typically, salmon respond to the screen in the following
manner. They swim upstream against the flow, enter the
electric field and jump violently back away from it,
retreating several hundred feet downstream. After several
attempts and shocks they approach more slowly and follow the
angled electric field to the safe passageway provided. If
they are immediately stunned, the downstream current will
carry them safely away from the screen.
The electric screen has the advantage of flexibility and may
be applied intermittently during time of need for intake
protection. The major disadvantages of the electric
screening system are as follows:
Cannot be used to screen downstream migrants.
41
-------
A GROUND LINE ON STREAM BOTTOM
UPSTREAM MIGRATING SALMON
ELECTRODE LINE
OVERHEAD -
STREAM FLOW
V = 0.9M/SEC
(3 FPS)
OR GREATER
DIRECTION OF FLOW
FISH BYPASSING
IN SLUICEWAY
PLAN
3.7CM
SCH. 40 PIPE
GALV.
0.91M (3'}
O. C.
1.3CM (1/2")
CABLE SUPPORT
0.94CM (3/8")
SOLID CORE ELECTRODE CABLE
60 CYCLE 110V A. C.
ill
\.
T
2/3 LOW WATER DEPTH
GROUND LINE RECESSED FLUSH
WITH BOTTOM 0.94CM (3/8")
ROPE CORE STEEL
ELEV. A-A
FIGURE III-7 TYPICAL ELECTRIC FISH FENCE
42
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Cannot be used to screen a mixture of sizes and
species because of different reactions that are
size and species related.
Cannot be used in esturarine or ocean waters
because of high electrical losses.
Can be dangerous to both humans and animals because
of the high voltages used.
The U.S. Fish and Wildlife Service terminated its research
on electric screens in 1965. Over fifteen years of
concentrated research had failed to solve many of the major
problems of electric screening systems. Several utilities
have investigated the problem in depth and some research is
still being conducted,but not much success has been shown to
date for downstream-migrant fish. In summary, electric
screens, while not generally successful, may work in some
situations.
Mr Bubble Screens
The fish response employed by an air bubble screen is avoid-
ance of a physical barrier. In its simplest form, the
bubble barrier consists of an air header with equally spaced
jets arranged to provide a continuous curtain of air bubbles
over the entire stream cross section, as shown on Figure
III-8.
Historically it was also felt that the sensory mechanism in-
volved in utilizing the air bubble screen was entirely
visual. This led to the conclusion, long held, that the
screen was not useful at night. More recent findings of
laboratory experiments conducted by a leading manufacturer.
Reference 30,, tend to refute this belief. Design and
performance data at two existing power stations were also
evaluated. In one case the screen was successful and in the
other unsuccessful. The laboratory tests were conducted at
the Edenton National Fish Hatchery in North Carolina and
involved striped bass and shad, 80 mm to 250 mm in length.
The test channel used is shown in Figure III-9. The fish
were hatchery reared and may not have shown typical swimming
behavior. Also note from the figure that the barrier was
established to prevent the progress of fish swimming against
the flow, which is the opposite of an intake situation. The.
results of the tests are reported in Reference 30 and are
summarized as follows.
-------
^ V
w.s.
FIGURE 111-8 AIR BUBBLE SCREEN TO DIVERT FISH FROM WATER INTAKE
45
-------
VEL. DISTRIB. AT
THIS POINT
PLASTIC
TANK
FISH TRAVEL
AGAINST FLOW
\
• \
BUBBL
0.6 ~
1.0 -
0.3 -
OBSERVATION SECTION (AIR
BUBBLE CURTAIN AND/OR LIGHT CURTAIN
PLACED HERE FOR TESTING)
\
) FLOW
)
1.2M
(4')
iTYfv
— PUMPS
0.29M TO 0.46M
(11" to 18") DEPTH
OF WATER
PLAN
FIGURE III-9 CHANNEL TO TEST EFFECTIVENESS OF AIR BUBBLE SCREEN AT
NORTH CAROLINA FISH HATCHERY
46
-------
When the air bubble curtain was placed entirely across
the 1.2m (U') channel, -the fish did not pass through in
any of the tests, even when attempts were made to chase
them through the curtain. ;
Temperature does influence the performance of the
barrier. The tests were conducted at 10°C, 4.5°C and
0.8°C (50°F, 40°F, and 33.5°F) . The bubble barrier was
a complete success at 10°C(50°F) and at t.5°C(40°F). At
0.8°C (33.5°F) the fish were lethargic and simply drifted
through the barrier with the current. This latter
effect would probably be shared with all systems which
rely on swimming ability of fish to escape an intake.
This particular bubble barrier appeared to be as
successful in complete darkness as well as in daylight.
This tends to refute the long held conclusion that these
systems will not work at night. It also indicates that
sensory mechanisms other than visual are involved, and
that future work is required to define the mechanisms
involved in fish response to this type of situation.
The air was injected through 0.08 cm (1/32M) round holes
at 2.5 cm (1") spacing. At 5.0 cm (2") to 7.5 cm (3")
spacing the fish passed between; the rising bubble
columns.
When the bubble system was placed 5.0 cm (2") off the
floor, fish did not pass under it. When placed any
further off the floor of the channel, the fish passed
unimpeded under the curtain.
A successful application of an air bubble screen was
reported in Reference 13. The system was installed at a
powerplant intake (plant no. 5521) on Lake Michigan in
Wisconsin. The principal fish species involved was the
Alewife, a variety of herring which is a heavily schooling
fish having a length between 15 and 20 cm (6" and 8"). The
plant has an average cooling water flow of some 18.3 cu
m/sec (290,000 gpm). The air bubble barrier extends across
the intake channel, well in front of the intake structure in
about 3.6 to 4.0m (12* - 13») of water. The air bubble
system consists of 2.5 cm (1") diameter PVC lines with holes
drilled on 10 cm (4") centers. The \total air flow is
approximately 0.047 cu m/sec (100 cfm) at 413.7 kN/sq m (60
psi). The air is supplied by a conventional compressor
drawing 15,000 to 19,000 W (20 - 25 hp). The optimum air
flow was,measured at 0.01 cu m/min (0.36 cfm) per 0.3 m (1
foot) of air header at 113.70 kN/sq m (60 psi).
47
-------
Prior to the installation of the air bubble screen, there
had been several shutdowns of the plant caused by schools of
Alewives jamming the screens and shutting off the flow of
cooling water. Since the installation of the screen, there
have been only one or two shutdowns of this type during more
than four years of operation. The major purpose of the air
bubble screen is to repel schools of fish rather than to
stop all individuals. The operation of the bubble system at
this plant has been equally successful at night as in
daylight. The operation of this system was considered so
successful that another utility located on Lake Michigan is
installing a similar system at a new nuclear station.
(plant no. 5519)
The performance of a similar system installed at a major
nuclear station in the Northeast (plant no. 3608) was
exactly opposite of that described above. The species
involved at this plant were the striped bass and white
perch. When the plant first went on line, there was a
serious loss of larger fish on the screens. A series of
modifications were made in an attempt to reduce the loss.
The modifications are shown in Figure 111-10 and consisted
of the following:
Removal of eight feet of the original curtain wall to
reduce the intake velocity. Average velocity over the
face of the screen before the modification was about
0.30 m/s (1 fps). After making the change, the summer
average velocity was 0.18 m/sec (0.60 fps), and the
winter average velocity was 0.048 m/sec (0.15 fps).
The installation of a fixed screen mounted flush with
the front face of the intake to allow the fish to swim
to the right or left to escape entrapment. This modi-
fication also eliminated the entrapment .zone between the
face of the screen and the existing vertical traveling
screen.
The installation of an air bubble system in front of one
of the four bays of the intake. The bubble s^ .tern
consisted of two vertical rows of horizontal bubbler
pipes. The first row was located three feet in front of
the intake and the second row was located six feet in
front of the intake. Each row of bubbler pipes has
seven horizontal pipes in a four foot center to center
spacing. Air was discharged through 0.08 cm (1/32 inch)
opening at 1.3 cm (0.5 inch) center to center spacing.
The first tests were run with 0.42 cu m/s (900 cfm) of
air which was far too large a quantity. The surface of
the water in front of the intake rose by as much as one
48
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NEW STATIONARY
SCREEN
\
I
AIR
HEADERS®,
1.2M (4')
P-P FAPM
STAINLESS
STEEL AIR PIPE
4 t
0 c
o c
o c
o c
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P C
.(
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6
J(-)1.5M
(-)5«
j(-)4M
(-)13'
o
-TRAV. SCREEN
2.
•^ —
\
0.9M
(3f)
1.8M
(6')
snHPMATir
C. W. PUMP
FIGURE 111-10
BUBBLE SCREEN INSTALLATION AT PLANT NO, 3608
TO REPEL FISH FROM WATER INTAKE
49
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foot in violent churning action. The entrained air
caused vibration problems in the pumps. The quantity of
air was subsequently reduced to 0.19 cu m/s (400 cfm)
which is the design value used in modifying all bays.
The total cost of these modifications for three
generating units at plant no. 3608 was approximately
$3.1 million. However, since this cost includes the
modification of intake bays it is not directly suitable
to judging the cost of air bubble systems per se.
The results of these modifications are as follows:
The effect of the air apparently was to reduce the
number of fish entering the bay equipped with the bubble
system, but the number of fish entering the remaining
three bays increased.
During July, 1972, tests, the test engineers were able
to discern no improvements in fish entrapment during the
daytime; at night the -fish being trapped in the bay
equipped with the bubble system appeared to be signifi-
cantly greater than in the bays with no bubbler.
The bubble barrier did appear to be effective in con-
trolling ice in front of the intake during freezing
conditions. This fact makes the bubble system
attractive as a possible replacement for the hot water
recirculation systems which are currently being used to
control ice at many existing installations. The
problems associated with hot water recirculation have
been discussed in an earlier section.
Air bubble screen tests have been conducted with salmon by
both the Canadian Department of Fisheries and the National
Marine Fisheries service (formerly Bureau of Commerical
Fisheries under the U.S. Fish and Wildlife Service). Tests
conducted at the Tracy Pumping Plant in the early 1950's and
under the 1964 Fish Passage Research Program, demonstrated a
large difference between night and day passage with salmon
with better response during the day.50
In summary, the air bubble system may have some application
at certain types of intakes. The system appears to be most
effective in repelling schooling fish. However, the mech-
anism of bubble screening is not sufficiently well under-
stood to recommend its adoption generally.
Behavioral Systems Employing Changes in Flow Direction
50
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The propensity of most species of fish to avoid abrupt
changes in flow direction and velocity has been demonstrated
on several occasions. This ability of fish to avoid
horizontal change in direction and velocity is the principle
on which the louver fish diverting system is based. On the
other hand, fish are generally insensitive to changes in
vertical flow characteristics. This indifference of most
species to vertical changes in flow regimen is the principle
upon which the "fish cap" or "velocity cap" intake is based.
Louver Barrier
The principle of the louver diverter is illustrated in
Figure III-ll. The individual louver panels are placed at
an angle of 90° to the direction of flow and are followed by
flow straighteners. The abrupt change in velocity and
direction form a barrier through which the fish will not
pass if an escape route is provided, iThe stream velocity is
represented in the figure as Vs. Opon sensing the barrier
the fish will orient perpendicular to the barrier and
attempt to swim away at a velocity vf. The resultant
velocity Vr carries the fish downstream roughly parallel to
the barrier to the bypass located at the downstream end of
the barrier. The controlling parameters in the design of
the louver system are the channel velocity Vs, the angle of
inclination of the barrier with respect to the channel flow
(10° to 15° recommended) and the spacing between louver
panels which is related to the fish size.
Most of the available performance data on the louver design
have come from tests of two prototype installations at
irrigation intakes in the Sacramento-San Joaquin delta of
California: the Tracy Pumping Plant of the California
Department of Water Resources, and the Selta Plant of the
California Department of Fish and Game.*7 The Delta intake
is shown on Figure 111-12. The facility is designed for a
flow of 170 cu m/s (6,000 cfs), and was tested at approach
velocities to the louver of 0.46 to 1.08 m/s (1.5 - 3.5 fps)
with bypass velocities of 1.2 to 1,6 times the approach
velocity.
The fish separation efficiency of the louver system drops
severely with an increase in velocity through the louvers.
For velocities of 0.46 to 0.6 m/s (1.5 - 2 fps), efficiency
was 61% with 15 mm fish and 95% with HO mm fish. When the
velocity was increased to 1.1 m/s (3,5 fps), efficiency was
35% for 15 mm (0.6 in) fish and 70% for HO mm (1.6 in) fish.
The following conclusions were reached as a result of these
tests. :
51
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Efficiency incre'ases markedly with fish size.
. Efficiency increases with lower channel velocities.
Addition of a center wall improves the efficiency,
giving the fish a wall to swim along if it wishes.
. Very careful design is required to take account of the
many variables, such as bypass ratios„ guide walls,
approach velocity, louver angle, etc. Each application
would most likely reguire extensive model testing to
define suitable design parameters, for the species of
concern at the temperature anticipated.
Individual louver misalignment did not have much effect.
In fact, efficiency even improved with a deviation from
the exact alignment.
Swimming capability is related to the length of the
fish.
The major
following:
disadvantages of the fixed louver system are the
The shallow angle of louvers with respect to the channel
flow requires a rather long line of louvers which will
increase the cost of the intake.
The louver system may not effect satisfactory removal of
trash. A conventional trash rack may be required
upstream and a set of conventional screens would be
required downstream of the louvers for more complete
trash removal. The performance of the louver may be
adversely affected in streams with a heavy trash load
thus possibly necessitating the use of conventional
coarse trash racks upstream to remove heavy debris.
A rather complex fish handling system may be required to
safely return fish to the water source.
Water level changes and flow variations must be kept
small to permit maintenance of the required flow
velocity.
In an attempt to overcome some of these limitations,
additional studies were conducted at a major power station
in Southern California (plant no. 0618). Of the major fish
types studied, the anchovy of about 130 mm (5.2 in) in
length was the most delicate. Another sensitive fish (200
mm (8.0 in) in length) was the queen fish. The strongest
54
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and toughest fish included surf perch and croakers. A
sketch of the test flume is shown in Figure 111-13 and
results reported in Reference 32 were: as'follows:
The louver efficiency increased .with flow up to 0.6 m/s
(2 fps) which was considered optimum.
The bypass design is very important. The optimum bypass
velocity was determined to be 1.1 m/s (3.5 fps).
. A 2.5 cm (1") louver spacing gave good results. In-
creasing the louver spacing to 1.5 cm (1.75") reduced
efficiency significantly.
The louvers should have a 20° or less angle with flow
direction. Increasing „.this angle markedly reduced
louver efficiency.
The louver system worked as well at night as during the
day. ''••.'.-. -'-"•••
The experience gained in these tests is being used to design
a new intake for a major nuclear installation (plant no.
0629). A sketch of this intake is shown in Figure 111-14.
The intake employs the louver principle described above.
The .louvers are mounted on frames similar to the
conventional water screens. Instead of the fixed louver
system, the louvers are rotated in a manner similar to a
traveling bar screen used in municipal wastewater treatment.
A water jet system washes any material from the louvers as
it passes over a standard trash trough. Behind these
vertically traveling louvers is a standard vertical
traveling fine screen similar to "that used at most
powerplant intakes. The louvered frames are so mounted that
the front of the frame is flush with the walls supporting
the entire mechanism so that fish may move unimpeded down
the face of the louver vanes. The' louver vanes serve as
trash racks. :
A very important element/ of the intake is the guide vane
system upstream of the louver faces. These vanes insure
that the flow does not turn before it reaches the louver.
Fish moving down the face of the louvers enter a bypass.
The bypass itself has a unique fish lifting system. Figure
111-15, which lifts the fish up several feet, where they can
be dropped into a channel for their return to the sea.
Supplementary water is also pumped into this channel.
55
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FLUME
15.3M (50')
LONG
ANGLE WAS
VARIED
20° USED
0.3M TO 1.2M/SEC
(VTO47SEC)
2.54 CM
11") BEST
SPACING.
1.45M3/SEC (50 FT3/SEC) MAX
0.61M JO 0.76M (2' TO 2'-6")
WATER DEPTH
11°C-22bC (52°F-72°F) WATER
LOUVER PANEL. ALSO RAN
TESTS WITH MESH SCREEN
IN POSITION
DESIGN OF THIS BYPASS
AREA CRITICAL, FISH MAY
REFUSE TO ENTER
PLAN
FIGURE III-13 TEST FLUME AT PLANT NO. 0618
56
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FLUSHING
FLOW
FISH
BYPASS
V
FISH
HOLDING
AREA & ELEVATOR
CONVENTIONAL
. BAR RACK
RIVER
/
FISH
RETURN
CHANNEL
*V V
V
PLAN
FIGURE 111-14 INTAKE STRUCTURE - PLANT NO. 0629, TO DIVERT FISH BY LOUVER
SCREENS AND RETURN THEM DOWNSTREAM
57
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0.38M
(16")
to
0.91M/SEC
(3VSEC) —
\
ELEVATOR BASKET
2.1M
OUTFLOW
^SCREEN
PLAN
15CM
a
?
CO
FISH SEEK
SAFETY IN
BASKET
0.63CM (%") MESH
BASKET
SECTION
15CM (6")
15CM (6")
0.3M ('Y
BOTTOM DESIGNED TO
OPEN UP WHEN
ELEVATOR DESCENDS,
PICKS UP FISH MILLING
AROUND AREA
FIGURE 111-15 FISH ELEVATOR FOR FISH BYPASS - PLANT NO. 0629
58
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A substantial amount of model testing was required to
develop this intake. The model work included the test
flume, the test set up for the lifting basket and all its
flow mechanisms, the detailed intake structure itself and
the detailed bypass system.
!
While it will be several years before ; performance data on
this intake will be available, its successful operation
would represent a large step forward in intake design. The
louver principle has been demonstrated both in model and in
large prototypes and should have a significant impact , on
future design of intakes. The cost of installing this type
of intake will be substantially higher than those of a
conventional intake.
Velocity Cap Intakes ,
The operation of a velocity cap is shown in Figure 111-16.
It is based on laboratory studies which show that fish do
not respond to vertical changes in direction, whereas they
show a marked ability to avoid horizontal changes in
velocity. By placing a cover over the top of a intake, the
flow pattern entering the pipe is changed from vertical to
horizontal. As shown in the illustration, the cap has a rim
around its edge to prevent water sweeping around the edge
and to provide more complete horizontal flow at the
entrance.
Velocity caps have been used since 1958, when one was in-
stalled at a ocean-sited power station in California (plant
no. 0623) . Many other plants on the Pacific Coast, in the
Caribbean and overseas have adopted the concept since then.
Improvements have somewhat modified the design shown in
Figure 111-16. (Reference No. 40). One problem with the
utilization of the velocity cap is that it is difficult to
inspect, since it is under water. Frequently, the only sign
that "the cap is not working properly is an increase in fish
on the screens.
Other Behavioral Systems
Other behavioral mechanisms have been experimented with in
conjunction with fish diversion. These include sound
barriers, light barriers and several types of fish
attraction systems. The types of experiments conducted in
regard to these systems have generally been more crude than
those discussed earlier. Consequently, the results are
generally less conclusive indicating that considerably more
59
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formal investigation is required before these sytems can be
fully evaluated. i . .
Light Barriers
The same test flume shown in Figure 111-13 and discussed in
Reference 30 was also used to test a light barrier system.
Upon approaching a light barrier placed across the full
width of the flume for the first time during the test, the
fish would mill around for 3 to 5 minutes before passing
through. On subsequent trips around the flume, they would
hesitate less and less until the time for each circuit was
reduced to that which existed without the light source.
This indicates that the fish rapidly become acclimated to
light which renders such a barrier useless. Other ^experi-
ments with the same apparatus using light in conjunction
with a bubble curtain were also unsuccessful. It was con-
cluded from these test that light had no effect from a
practical standpoint. As far as could te determined, there
are no existing intakes where a light barrier is functioning
successfully. Light also has the adverse effect of
attracting fish under certain circumstances and has resulted
in the complete shutdown of plants.
Sound Barriers
Fish have been shown to respond to sound of high intensities
and low frequencies, but become accustomed to constant sound
levels. It has been shown that minnows respond to frequen-
cies up to 6,000 Hz and catfish to 13,000 Hz or only
slightly less than the 15,000 Hz band considered normal for
humans. Other fish respond to frequencies up to only 1000-
2000 Hz and are less sensitive to sound intensity. This
high variability to sound among different species is a major
drawback to this type of system.
There have been many attempts to direct fish around intakes
using sound barriers. A recent installation at a major
nuclear station in Virginia (plant no. 5111) employed rock
and roll music broadcast at relatively high intensities
under water. This type of music was selected because of its
multi-frequency nature and because it is non-repetitive.
The conclusion was that the system appeared to be at least
partially effective. However, due to the many species and
and sizes involved and the diversity of responses, it was
decided to install a mechanical system to reduce the fish
entrapment problem. The sound system will continue in use
while the mechanical system is being installed. A
61
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discussion of the proposed mechanical system is contained in
another section of this report.
Applicability of Behavioral Screening Systems
In summary, none of the behavioral systems have demonstrated
consistently high efficiencies in diverting fish away from
intakes. The systems based on velocity change appear to be
adequately demonstrated for particular locations and
species, at least on an experimental basis. More data on
the performance of large prototype systems at powerplants
will be required before the louver system can be recommended
for a broad class of intakes. The velocity cap intake might
be considered for offshore vertical intakes since it would
add relatively little to the cost of the intake and has been
shown to be generally effective in reducing fish intake to
these systems.
The performance of the electric screening systems and the
air bubble curtains appear to be quite erratic, and the
mechanisms governing their application are not fully
understood at the present. These types of systems might be
experimented with in an attempt to solve localized problems
at existing intakes, since the costs involved in installing
these systems can be relatively, small.
No successful application of light or sound barriers has
been identified. It appears that fish become accustomed to
these stimuli, thus making these barriers the least
practical of the available behavioral systems on the basis
of current technology.
Physical Screening Systems
All cooling water intake systems employ a physical screening
facility to remove debris that could potentially clog the
condenser tubes. Such facilities range from simple
stationary water screens to filter beds. This sub-section
will consider only mechanical screening mechanisms. In
general, these mechanical screens have been developed to
protect the powerplant from debris, rather than to protect
aquatic life.
In other sections intake facilities are reviewed as a whole,
with further consideration of the installation and operation
of some of the mechanical systems discussed here. Also
reviewed in other sections is the important area of fish
repulsion systems based on the behavioral characteristics of
fish.
62
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The following mechanical screening devices are the principal
types which are either in common use or have been suggested
for use in powerplant circulating water systems, both in the
United States and abroad.
1. Conventional vertical traveling; screens
2. Inclined traveling screens
3. Fixed screens
1. Perforated pipe screens
5. Double entry, single exit vertical traveling screens
6. Single entry, double exit vertical traveling screens
7. Horizontal traveling screens
8. Revolving drum screens - vertical axis
9. Revolving drum screens - horizontal axis
10. Rotating disc screens
Most of the types of revolving drum and rotating disc
screens are commonly used in powerplants outside the United
States and have been supplied by European manufacturers.
They have not been used for thermal powerplants in the
United States. :
Conventional Vertical Traveling Screens
By far the most common mechanically operated screen used in
U. S. powerplant intakes is the vertically-rotating, single-
entry, band-type screen mounted facing the waterway. A
catalogue cut of this screen is shown in Figure 111-17.
Figure 111-18 is a schematic drawing showing the principal
operating features.
The screen mechanism consists of the screen, the drive
mechanism and the spray cleaning system which requires a
means for disposal of the waste materials removed from the
screen. The screen is attached to an endless chain belt
which travels in the vertical plane between two sprockets.
The screen mesh is usually supplied in individual removable
panels referred to as "baskets" or strays". A continuous
band screen is also available but is nqt often used. The
entire assembly is supported by two or four vertical steel
63
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Head
terminal
Electrofluid
Motogear
Spray pipes
and nozzles
Head
sprocket
Foot
sprocket
Foot shaft
CONVENTIONAL VERTICAL TRAVELING SCREEN
Figure 111-17
64
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SCREEN DRIVE
SPRAY NOZZLES
FOR CLEAN ING
DEBRIS TROUGH
HIGH WATER
SCREEN BASKETS
(OR "TRAYS")
OPERATING DECK •„
WATER FLOW/
CLEAN
- FLOOR OF SCREEN
STRUCTURE
FIGURE 111-18 CONVENTIONAL VERTICAL TRAVELING SCREEN
65
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posts. Longer and wider screens usually require
stronger four post box structure for support.
the
The screen washing system consists of a line of spray
nozzles operating at a relatively high pressure, 550 to 827
kN/sq m (80 - 120 psi). The washing system may be located
at the front or the rear of the screen, or both. The usual
location is in front as shown in Figure 111-18. The
quantity of water required for spray cleaning is on the
order of 0.372 m/s (98.42 gpm) per meter (3.28') of screen
width. It is supplied either by booster pumps taking
suction from the circulating water pump discharge or by
separate vertical shaft pumps. The disposal of the debris
is usually accomplished by discharging the screen wash
waters from individual screens to a common disposal trough
located at the floor on which the screen is mounted. The
trough drains either to a debris storage compartment or
directly back to the waterway. If a debris storage
compartment is used, the water is allowed to drain from the
bottom of the compartment and the remaining refuse is
periodically removed to a land disposal area. Both the
drive shaft and the screen wash system are enclosed in a
removable housing to protect the drive components and to
contain the high pressure water spray.
The conventional vertical traveling screen has several ad-
vantages. It is a proven off-the shelf item and is readily
available. It performs efficiently over a long service life
and requires relatively little operational and maintenance
attention. It is applicable to almost all water screening
situations. It is available in lengths up to about 30
meters (1001) and 15 cm (6") increment widths up to 4.26
meters (14'). The system adapts easily to changing water
levels. The screen is relatively easy to install. Major
components of the system, including supports, baskets, drive
mechanisms, and spray systems are standardized. Special
materials for corrosion protection and greater durability
are also available.
The system as presently used has several undesirable
features potentially related t6 adverse environment impact.
The most important of these is the fact that any fish
impinged on the mesh of the screen will probably be
destroyed. This effect results from both the design of the
system and the way it is operated. Most traveling water
screens are operated intermittently, not continuously, and
fish can be pinned against the screen during the extended
periods of time while the screens are stationary. When the
screens are rotated the fish are removed from the water and
then subjected to a high pressure spray. Any fish surviving
66
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these hazards will
disposal operations,
waterway.
be destroyed in the subsequent refuse
if the refuse is not returned to the
The above discussion suggests the following possible avenues
for improving this technology i to minimize adverse
environmental impacts. !
a. reduce impingement time by continuous
the screen. '
operation of
b. provide a path for rapid and safe return of fish to
the waterway.
c. mount the screen so as to provide fish escape
passages to either side, a feature discussed in the
section concerning overall intake design.
d. Place screens at an angle to flow to lead fish to a
bypass system.
The current design of traveling water screens and the screen
structures themselves would not require radical changes to
adopt the first two of the possible corrective measures
listed above. Several intake designers and screen
manufacturers have proposed modifications of this type in
past years and at least one major nuclear station (plant no.
5111) is modifying its screen baskets and operational
procedures to provide fish protection. These modifications
are discussed in a subsequent portion of this report.
Inclined Screens !
Hundreds of inclined screens have been in successful
operation at fisheries in Europe, the United States and
Canada since the late 19UO's. Most are inclined downstream
away from the flow, some upstream, and a few are humpbacked
with screen sloping in both directions and a small amount of
water going over the top.3*
One type shown in Figure 111-19, is merely an adaptation of
the conventional vertical traveling screen. It is used at
installations where the debris loading is extremely heavy
and is of a nature that does not readily adhere to the
screen. The downstream inclination of the screen (usually
10° to vertical) allows debris falling off the lip of one
basket to be caught in the following basket rather than
falling back into the waterway. Also, by inclining the
entire screen frame, debris being lifted from the channel is
supported more fully by the ascending basket lips and the
67
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backward tilted screen wire. This type of screen thus might
be advantageous in insuring more rapid removal of fish,
shellfish and jellyfish from the waterway for subsequent
bypass as discussed above. The number of installations
using this screen is relatively small and the system has the
same advantages and disadvantages as the vertical traveling
screen. The cost of this screen would be slightly higher
than that of the vertical screen, due to the longer screen
well required, the use of two rows of spray nozzles and
other minor variations from the conventional vertical
screen.
Another type of inclined screen has been designed specifi-
cally with fish protection in mind and has significantly
different design features than the conventional vertical
traveling water screen. One variation of this type is shown
on Figure 111-20. There are many screens of similar design
in use for irrigation diversions. This type of inclined
screen is being used in the northwestern states at a number
of installations. The City of Tacoma Power and Light
company and the corps of Engineers have model tested this
screen design. At the Portland General Electric Company's
Pelton Dam, the screen was designed for a 7-foot
fluctuation, and at the Corp's Green Peter Dam, the screen
operates over a 100-foot forebay fluctuation. In both
cases, the entire screen moves vertically with water surface
fluctuations.s°
Such screens are still being modified through
experimentation. The screen shown in Figure 111-20 has been
used in Canada to divert downstream migrating fish and its
performance is reported in Reference 21. This system
employs a fixed screen inclined downstream at an extreme
angle to the vertical. The rear portion of the screen is
bent horizontally over the fish collection trough. The
screen is cleaned by a continuous chain flight conveyor
similar to that used in conventional water and wastewater
sedimentation practice. The differences are the orientation
of the collector above the screen and the conveyor flights
which are made of a pliable brush material rather than solid
metal. By orienting the screen and cleaning mechanism in
this manner the fish can be slowly herded up the screen and
kept immersed in water until it is dumped gently into the
bypass trough. This design avoids many of the pitfalls of
impingement on vertical traveling screens. The fish is not
really impinged in the real sense of the word. It never
leaves its normal habitat of water and is not subjected to
the extreme pressures of the conventional system spray
water.
69
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HOIST *~
STRUCTURE !
9
CIRC. WATER
PUMP
----- "FIXED" SCREENS
\ (2 SETS OF 2)
: SERVICE
WATER PUMP
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FUTURE H
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A ' ;
/ TRASH RACK
& STOPLOGS
i
i
i
_
i_
• '
i
•
!
1
k
\ '. '
%
v
j* ~
/ •• • —
i
i
j
i
_.
.
•^
— ALTERNATIVE FIXED
SCREEN FOR RELATIVELY
SMALL PUMPS
FIGURE 111-21 FIXED (STATIONARY) SCREENS (SCHEMATIC ONLY)
73
-------
This particular system has some important limitations. It
is sensitive to fluctuations in water level, since the water
level variation at the horizontal section of screen must be
limited to a few inches; a level control mechanism such as
the slide qate shown in Figure III-20 is thus required.
Some designs"have, however, provided for moving the screens
up and down with the changing water level. Another
disadvantage is that the overall cost of the int;*ke
structure for this type of screen could be increased. The
shallow angle of placement with respect to the incoming flow
causes the length of the intake channel to be several times
longer than that required for the vertical traveling screen
of the same screening capacity.
The application of this type of system, as well as several
others to be discussed, could be limited in many areas
because of the regulations of cognizant water quality
control agencies. Reference here is to the possible
prohibition of the subsequent discharge of debris after it
has been removed from the waterway.
As can be seen from Figure 111-20, the method of diverting
fish to the bypass trough also allows for the discharge of
the debris back to the receiving water. Debris can cause
injury to fish in the bypass system, particularly if it
becomes lodged or if there is excessive turbulence in the
bypass flow. Prohibition of this debris discharge could
also result in the prohibition of safe fish return. It is
apparent that the same comment applies to the discharge from
the conventional traveling screen previously discussed. In
cases where it is required that fish be separated from the
debris some difficulty may be encountered, since the only
known technology for this would involve manuajL separation.
Conceivably gravitational separation techniques could be
employed.
The screen shown in Figure III-20 is a variation of the
humpback. A similar installation of the humpback type has
been in successful use at the Pelton Project on the
Deschutes River in Oregon over the past 16 years. Virtually
the only difference is that the Pelton "skimmer" uses a
perforated stainless steel plate 5.4 m (18 ft) wide by 8.1 m
(27 ft) long instead of screen and has no mechanical
cleaning inasmuch as it is self cleaning except for minor
filamentous algae growth in summer. Passing 200 cfs, it
operates through a 2.1 m (7 ft) range of water levels with
an approach velocity of 4.5 to 5.4 mps (15 to 18 fps) which
assures that most fish and smaller organisms including
larval forms are carried over into the bypass regardless of
71
-------
resistance. It
installation s.3'
Fixed Screens •
is not applicable to deep water
This term is applied to a number of different types of
screens, some of which are permanently anchored below the
waterline of intakes and others, the more common, which can
be moved but are not capable of continuous travel. Taken
together "fixed", screens (or "stationary" screens)
constitute the second largest group of physical screening
devices presently found in powerplant intakes. Examples of
two types of screening systems in this category are .shown in
Figure 111-21. Both types of screens would not be used at
the same intake and are only shown on the same figure for
convenience.
The first type of screen is mounted upstream of the pumps in
vertical guides to allow them to be removed to a position
above the water line. Figure 111-21 shows a relatively
sophisticated installation wherein two rows of screens are
provided to permit one to remain in service while the other
is being changed. In addition, each row is divided into two
sections in a manner which allows removal of the lower
section without removal of the upper section. - Some debris
and fish can be sucked into the pump during the process of
changing screens. The screen guides are sometimes extended
above the deck to hold the raised screens,in place for
cleaning. Figure 111-22 is a sketch showing typical
fabrication details of such a screen.
Another fixed screen type, involves a cylindrical screen
attached to the pump suction bell. The cleaning of this
type of screen is very difficult; it may be done by
dewatering the bay, with the use of divers or by backwashing
through the pump, all methods being unsuited to the
•continuous pump operation required at powerplants.
The bulk of fixed screens are found on smaller and older
plants. Some newer plants located on water bodies that have
small debris loadings have also installed this type of
screen. An advantage over a conventional traveling water
screen is a savings in the cost of the mechanical equipment
and in maintenance costs for the screens, screen drives,
spray wash pumps, etc. Operating costs may be higher if
frequent manual cleaning is required. Often a fixed-screen
structure will require more than twice the total screen area
as a self-cleaning screen due primarily to the infrequency
of cleaning the screen. Thus, cost savings over a self-
cleaning screen cannot always be related to just the
72
-------
-PUMPS
GATES
" BACKWASH
CONNECTIONS
NORMAL LOW WATER LEVEL
SECTION A-A
FIGURE III-22A PERFORATED PIPE SCREEN (IN RIVER CHANNEL)
76
-------
perforation velocity,, size and shape, all specifically to
provide maximum fish protection. Additions to the inside of
the pipe, such as sleeves, may be made to produce equal
velocxties through the perforations. Very low approach
velocities can be achieved with a reasonable total length of
perforated pipe, divided into several individual pipes if
necessary. In this manner large quantities of water may be
handled at what may be substantially less cost and greater
fish protection effectiveness than presently used
conventional screens.
Backwash provisions may be included as shown in Figure III-
22A, but a review of existing installations has indicated
that these provisions have not been extensively needed.
Other Vertical Traveling Screens
Double Entry, Single Exit Vertical Traveling Screens
Figures 111-23, 111-24, and 111-25 show two types of
installations for a vertical traveling screen which takes
water from both sides and passes it out through one end of
the screen, thus doubling the screening area for a given
width of screen. Although this unit appears similar to the
conventional traveling screen there are significant differ-
ences.
Figures III-23 and 111-24 show the most common mounting of
this type of screen. The unit is turned so that the
approach flow is parallel to the faces of the screen, it is
mounted in a concrete screen well. Water enters through
both the ascending side and the descending side of the
screen, thus utilizing both sides for water cleaning. For a
given theoretical mesh velocity the screen will have twice
the capacity of the conventional screen. There is no
possibility of debris carry over to the pump side, since
incomplete cleaning will simply result in returning the
debris to the incoming water for recycling.
There are several drawbacks to this type of installation as
outlined below:
a. The clean screen face is first introduced to the
flow at the water surface. The debris picked up by the
descending baskets must then be pulled down and through
the boot section. Debris thus collected on the
descending run blocks the screen,for the entire cycle.
This is in contrast to the single entry screen which
oresents a clean basket to the flow and usually does hot
77
-------
Guide sprocket
with chain
tensioning
device, adjustable
with screen
running
Wash water
supply
connection
Non-cocrodible
main chains
30,000 Ib breaking
load. Low friction
Nylon rollers
Screen slides
into locating
members
and can be
withdrawn
bodily if
required
OUTLET
Screened
water
DOUBLE ENTRY, SINGLE EXIT
VERTICAL TRAVELING SCREEN
Figure 111-23
Wash water
and debris
chute, tc
drain.
Driving gear
Driving sprocket
— Double row of
wash water
fan-jet nozzles
in splash proof
casing
Main frame 'H'
members, with
guide channels
and wearing
strips for chain
rollers
Non-corrodible
screen panels
witn deep buckets
for lifting debris,
replaceable without
dismantling
main chains
Fabricated steel
supporting feet,
chain-roller guide
paths continued
in large radius
round base
78
-------
CIRC. WATER
PUMPS
VERTICAL / r
TRAVELING
SCREENS :
WATER FLOW
"V\
V
I t
INFLOW
PLAN
- BLANK PLATE
VERTICAL
TRAVELING
SCREENS
SCREEN FACE
JS **
J I
L
1
|
~r-
•' . ^
\ ,-
*:
w. s
f1 1
'
V J
\ SP
-^'_-*l
- 1 Tfi
ILT
A «» «j
—-ft
1
1
1
.,
A
"
A
^
SPRAY SYSTEM
TRASH TROUGH
SCREEN FACE
SECTION A-A
FIGURE 111-24 DOUBLE ENTRY, SINGLE EXIT VERTICAL TRAVELING SCREEN (SCHEMATIC ONLY)
79 :
-------
•^£fe
-- .•• ...
•'•"'' '
DOUBLE ENTRY SINGLE EXIT
VERTICAL TRAVELING SCREEN
OPEN WATER SETTING
Figure IT.I-25
80
-------
encounter the majority of the debris until
it lifts out of the water. "
just before
b. Since head loss increases on an exponential basis
with the degree of blockage of the screen wire, the dual
flow screen will have to be designed to operate under
higher head losses or a higher rate of screen travel.
Higher head loss design requires both a structurally
stronger screen and a higher horsepower drive.
c. The double entry screen mounted as in Figure 111-22
requires abrupt changes in water flow direction as it
passes through the screen. This will result in non-
uniform flow across the screen face, with high localized
velocities, additional system head loss and possibly
enough turbulence to upset pump operation.
d. The common setting shown in Figure 111-22 does not
provide any escape route for fish other than to swim
back out of the channel. Definite fish trap areas
result at both faces of the screen.:
This type of screen is frequently used outside the United
States and ijs also offered as a standard item by one U. S.
manufacturer.
Figure IIi-25 shows an environmentally promising alternative
mounting for the double entry screen. Here the screen is
mpunted on a platform and is surrounded by water on all
sides.
There is no confining concrete structure which might trap
fish. This is potentially a major asset from the point of
view of fish protection. The screen has some of the
mechanical drawbacks of the mounting shown in Figures 111-23
and III-24. In addition, the pump suction piping will cause
non-uniform flow through the screen mesh since abrupt flow
direction changes must take place to get the water to the
pump. Not shown in Figure III-.2 5 are trash racks and
associated structure which will probably be needed to
protect the screen from heavy debris. Even with such added
facilities, however, the total cost of the screen and pump
installation for the open type mounting may well be less
than for an installation using either conventional traveling
screens or the screens mounted as shown in Figures 111-23
and III-2U.
It might be noted here for reference that the principle of
the open type of screen mounting typified in Figure 111-25
is also a feature of one of the alternative mountings of a
81
-------
European drum screen shown in Figure 111-38. The pump
suc-tion piping is similarly attached to the screen frame
itself, allowing open water to surround the screen, thus
avoiding fish trap areas.
Single Entry, Double Exit Vertical Traveling Screens
Figures 111-26 and III-27 show a screen type which reverses
the flow path shown for the double entry screen previously
discussed. Water enters through an opening in one side of
the screen frame and exits to both the right and left
through the ascending and descending screen faces. Debris
is removed from the screen baskets into a trough on the
inside of the screen by both gravity action and sprays.
There is no possibility of carrying debris over into the
"clean" side of the system. None of these European designed
double exit screens is presently in operation in the United
States, but they are on order for at least two major U. S.
powerplants. .
The advantages and disadvantages of this design are similar
to those for the double entry screens previously discussed.
One potential fish protection feature of the screen shown in
Figure III-27 is a substantial debris, water and fish
holding trough for each section of individual curved screen
basket. Fish might be less likely to flip out of the trough
back into the incoming water and thus would not be
"recycled" in the manner which is objectionable on
unmodified conventional traveling screens.
Neither this screen nor any of the other vertical traveling
screens were developed with fish protection in mind. Thus
they have the inherent and obvious potential environmental
drawbacks which have been highlighted in the previous
discussions.
Horizontal Traveling Screens
Figure 111-28 shows the principle of the horizontal
traveling screen, a device specifically developed to protect
fish. It elicits a behavioral response from the fish
similar to the louver diversion system discussed elsewhere
in this report. The horizontal screen, which is still in
the experimental stage, is the single major advance in
mechanical screening technology in the last decade. It was
initially developed by the Bureau of Commercial Fisheries,
now the National Marine Fisheries service. Later financial
82
-------
SINGLE ENTRY, DOUBLE EXIT
VERTICAL TRAVELING SCREEN;
FIGURE 111-26 !
83
-------
n
LLLLLLi iJJ 11 L. >-i-L! J j^.J.1.
A
.111U.LLHLL! .IJJI JJJJ.LJ.I
1 t
PLAN
INFLOW
TRASH TROUGH
HL PRIOR TO
CIRC. WATER PUMPS
EMERGENCY SCREEN
BYPASS GATE
VERTICAL
TRAVELING
SCREEN
/ EMERGENCY
BYPASS GATE
SECTIOJM A-A
FIGURE 111-27 SINGLE ENTRY, DOUBLE EXIT VERTICAL TRAVELING SCREEN
84
-------
TO PLANT
SCREEN
/DIRECTION
HORIZONTALLY
ROTATING SCREEN
WATER FLOW
FISH CHANNEL
PUMP FOR FISH
DIVERSION .
PLAN
SCREEN DRIVE:
FISH RETURN TO RIVER I
PUMPS'
WATER LEVEL VARIATION -i
TRASH
BARS
SECTION A-A
FIGURE 111-28 HORIZONTAL TRAVELING SCREEN (SCHEMATIC ONLY)
85
-------
and technical support has come from several utilities and a
commercial screen manufacturer.
As shown schematically in Figure 111-28, the horizontal
traveling screen rotates horizontally at a sharp angle to
the incoming water flow. The principle is to guide fish to
a point where a bypass channel can carry them to safety. It
has been very effective. Upon sensing the screen, a fish
will orient perpendicular to the screen and attempt to swim
away from it in a direction opposite to the vector VR. This
he is able to do since the component of the channel velocity
opposing his effort (VF) is small.' In this orientation the
fish is swept downstream along the face of the screen by the
component of channel velocity which is parallel to the
screen (VS). When the fish reaches the end of the screening
leg it moves into the bypass channel for safe passage back
to the waterway. The size of fish that is effectively
screened can be reduced by reducing the angle of inclination
of the screen with respect to the channel flow direction,
which increases the total screening area. However, as this
angle is reduced the size of the screen increases for the
same flow rate, increasing the cost of the intake. Some
small percentage of fish will become impinged on the screen,
but they will be released at the bypass and may also not be
pressed as tightly against the screen as they would be in a
vertical screen depending on the dynamic head against each
type of screen.
The latest experimental version of this screen (designated
Mark VII) is shown schematically in Figure 111-29. It is
located on the Grande-Eonde River near Troy, Oregon and was
designed in cooperation with a major commercial screen manu-
facturer. Although this screen and its predecessors have
undergone extensive tests, the manufacturer and
knowledgeable intake designers estimate that it is at least
two generations of experimentation away from installation at
a major steam electric powerplant. Application of this
screen to a large industrial intake at this time would
require extensive and costly research.
Some of the problems are as follows:
a. The screens operate continuously and at very high
rates of speed compared with vertical screens. For the
Mark VII screen the rate of travel is variable from 0.4
to 1.2 m/s (80 - 240 fpm) as compared with a usual
maximum of 0.05 m/s (10 fpm) for the vertical screen.
All components of the mechanism are thus subject to
severe wear. Reliable, long life components have not
been developed.
86
-------
\- M
~ PANELS NORMALLY
' J)PEN ON BACKSIDE^ _
SEAL.
FISH AND
DEBRIS BYPASS
SCREEN WIRE:
0.071 CM DIA.
#8MESH -60% OPEN
NET 35% OPEN FOR
OVERALL SCREEN
& STRUCT. ELEM.
PANELS IN EMERG.
OPEN POSITION
\ \ (TO PASS DEBRIS
\ \ nvi
SCREEN 1.8+M
HIGH, WATER
DEPTH 1.5 M±
RATE OF SCREEN
TRAVEL.V:
Og4 TO 0}7 M/S
10 HP MOTORS
FIGURE III-29 MARK VII HORIZONTAL TRAVELING SCREEN (SCHEMATIC ONLY)
87
-------
b. Water level differential due to clogging must be
limited to avoid collapse of the screen. Either the
pumps must be tripped to stop flow or the screen panels
must be designed to spring open. This latter solution
was used in the Mark VII screen. If the panels thus
open they will release fish and debris and supplementary
conventional traveling screens will be required
downstream of the horizontal screens to protect the
cooling water system.
c. The horizontal screen cannot accommodate significant
variations in water depth in its present stage of
design. Effective performance hinges on suitable
approach water velocities.
d. The maximum screen panel height is about 4.3 meters
(14 feet) due to the same general structural limitations
that control the maximum width of a vertical traveling
screen.
e. Due to the lack of a velocity gradient in the
incoming water screen, it is difficult to obtain
sufficient bypass velocity without the use of
supplementary pumps in the bypass system.
f. Debris as well as fish must be handled on the bypass
system, thus required additional water cleaning
facilities.
g. Screens would have to be redundant to permit con-
tinuous full load operation during screen maintenance
shutdowns. The size of the installation will thus
become very large and costly compared with a vertical
screen facility.
h. Debris and bed load tend to jam lower tracks.
Figure III-3Q is a schematic version of a possible variation
of the horizontal screen setting. This location and
orientation would utilize the velocity of the passing water
to carry the fish to safety and remove trash.
The principle of angling the water cleaning facilities to
the incoming flow is further developed in other sections,
with respect to the louver system of behavioral guidance and
the concept of placing conventional traveling screens at an
angle to the flow.
Revolving Drum Screens
88
-------
.U'.ij/Liif
tRASH BARS
ItD.i.iJ3.i.i'.TEE[ ]
CONTINUOUS
ROTATION
o
o
SPRAY HEADER
FOR TRASH REMOVAL
CIRC. WATER PUMPS
FIGURE 111-30 SCHEMATIC PLAN ADAPTATION OF HORIZONTAL
TRAVELING SCREEN
89
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Revolving Drum Screens -. Vertical Axis
At least two types of vertical axis revolving drum screens
are in use in U. S. water intakes, tut not in facilities
connected with industrial cooling water systems. The
California Fish and Game Department has had in operation for
several years a revolving drum screen-vertical axis equipped
with a fish and trash bypass systems for an irrigation
diversion.so
a. The vertical drum revolving in an opening in front
of the pumps is shown schematically in Figure 111-31.
b. The vertical -drum revolving around the pump
is shown in Figure III-32.
itself
The screen mesh is placed on a vertically revolving drum.
Water level variations can be handled without difficulty. A
vertical jet spray system can be mounted inside the drum to
wash off debris. However, no convenient way has been de-
veloped to move the debris away from the screen face area.
Figure III-31 shows the drums lined up in such a manner that
a passing river flow will carry away debris and would also
carry fish to safety. Obviously the reliable performance of
this system will depend on a strong unidirectional passing
current, which is a feature severely limiting the number of
locations where the screen would be effective. Without such
passing flow the debris would simply pile up in front of the
screens. Fish would be scraped or jetted off only to
possibly impinge again on the same or adjacent screens.
Figure 111-32 shows the screening element encircling the
pump and revolving around the pump. One major screen manu-
facturer has supplied such screens • for relatively small,
0.19 cu m/s (3,000 gpm) , powerplant auxiliary pumps.
Another version has been independently developed and used
for an irrigation water intake by the Prior Land Company of
Pasco, Washington. Although this system is experimental and
has been in operation for only about a year it has served
Prior Land's special needs. The system has had mechanical
difficulties, however, and has required major overhaul
during the non-irrigation season. Modifications and new
designs are underway, A vertical spray washing system has
been installed, but no satisfactory provisions have been
made to carry the debris away once it has been washed from
the face of the screen.
The screen enveloping the pump must be large in diameter
compared with the bell in order to achieve an acceptable low
90
-------
RIVER FLOW
A
L
TRASH BARS
|
"." •' ' ' I CTJ
-------
LU
LLJ
OC
O
CO
or
a
o
UJ
cc
CO
X
O
l-
oc
til
ui
cc
C3
-------
screen velocity. Only a small vertical section of the
screen will be effective since the flow lines into the pump
bell traverse only a limited area of the surrounding
waterway.
The vertical drum screens described here are not suffici-
ently developed to assure protection to fish and appear to
be of marginal effectiveness in handling any but very light
debris loads.
Revolving Drum Screens - Horizontal Axis
Horizontal axis revolving drum screens are widely used
throughout the world. There are many variations functioning
in quite different ways. In the United States, however,
they have had practically no application and are not
supplied as Ja standard design for the water quantities
required in powerplants. The reason revolving drum screens
- horizontal axis, have not been used with cooling water
intakes in the U.S. appears to be that previously, the main
concern has been with the need to remove debris from, the
water for protection of the plant. For the majority of drum
screens, the National Marine Fisheries Service has found
that the flow .through the screen is adequate to remove all
debris on the downstream, side of the screen. If used in
this manner, the plant could require additional trash
removal equipment downstream of the screen.50
A simple drum installation is shown in Figure 111-33. This
type of screen is placed with its longitudinal axis
horizontal across the intake channel. The screening media
is located on the periphery of the cylinder. The screen
rotates slowly with, its exposed upper surface moving
downstream (intake flow) just below the water surface.
Because it operates in this manner it can be used to
separate fish from the water flow with minimum impingement,
if mesh approach velocities are low. Debris is not removed
efficiently.
The important design parameters for the drum screen are mesh
size, drum diameter, drum rotation velocity, and Velocities
through the screen. The velocities through the screen are
difficult to control since portions of the screen are alter-
nately moving with and against the intake flow, although in
the usual case of low drum speed this effect would be minor.
The horizontal drum screen as shown is also sensitive to
water level changes.
Drum Screens - General
93
-------
cc
UJ
>
UJ
ol
- Jn 1
/—i . •-
*T=^
Ul
cc
o
oc
fc
S2
UL
UJ
oc
(9
-------
water screening has not been given much attention.
following types are readily available and often used:
The
a. Figure III-35, single entry cup screen, where the
water enters at the end (side) of a large rotating drum
and passes out through screen mesh on the periphery. It
is limited in size to about 9 m (30•) in diameter
because of the cantilever nature of the shaft support.
b. Figures III-36 and III-37, double entry cup screen,
where the water enters the rotating drum from both ends
(sides) and passes out through the mesh on the
periphery. These screens have been made as large as
18.3 m (60*) in diameter. Efforts have been .made to
provide oversize debris lifting buckets to carry fish in
water up to the debris removal system and trough at the
top .of the drum travel.
c. Figure 111-38, a double entry drum screen where the
screen mesh covers the ends (sides) of the drum and the
periphery is closed. Water enters the sides and also
leaves one side through a pipe around which the drum
rotates. This screen rests on piers without a
surrounding concrete structure, a mounting which permits
water flow around all sides and which thus provides
escape routes for fish. In this respect the setting is
similar to the double entry vertical traveling screen
offered by a u. S. manufacturer and shown in Figure
111-25. Screens of this type cannot be cleaned
efficiently because of the tendency for the debris to
fall back into the raw water as the screen rises.
The structure required to mount drum or cup screens is sub-
stantially larger and more costly than the vertical
traveling screen structure designed to handle the same
quantity of water under the same conditions. They are
reputed to be easier to maintain (the horizontal shaft is
located above normal water level), there are fewer
mechanical parts and there is no possibility of carryover of
debris into the circulating water system.
Rotating Disc Screen •
Figure 111-39 shows a typical rotating disc screen, a type
which is suitable only for relatively small flows and small
water level variations. The screen mesh covers a flat disc
set at right angles to the water channel. The disc rotates
around a horizontal axis, bringing the dirty screen face
above water where high pressure sprays wash the debris into
97
-------
DEBRIS REMOVAL SYSTEM
ROTATION
SECTION ON A-A
SCREENED WATER
f\\ •
DIRECTION OF FLOW
UNSCREENED WATER
SINGLE ENTRY CUP SCREEN
Figure 111-35
98
-------
DEBRIS REMOVAL SYSTEM
ROTATION
DOUBLE ENTRY CUP SCREEN
/Figure III-36
99
-------
DOUBLE ENTRY CUP
SCREEN
SCREEN STRUCTURE WITH
DOUBLE ENTRY CUP SCREENS
Fieure IT.I-37
700'
-------
,-J
MESH SCREEN
SECTION A-A
RUBBISH
HOOD
RUBBISH
TROUGH
UNSCREENED
WATER
SYPHON PIPE
TO PUMPS
SCREENED
WATER
SCREEN MESH
BOTH SIDES
ELEVATION B-B
FIGURE 111-38 DOUBLE ENTRY DRUM SCREEN OPEN WATER SETTING
101
-------
Rotation
Access platform
If required -
Screening panels
ROTATING DISK SCREEN
BASIC ELEMENTS
ROTATING DISK SCREEN
IN OPERATION
Figure 111-39
102
-------
a trough similar to that used for conventional traveling
screens. it has a minimum number of moving parts and is
thus inexpensive to buy and maintain* The circular screen
shape makes relatively inefficient use of available area of
the incoming water channel. No more than about 35% of the
total screen face is being used at any one time.
Such a screen has no general advantage over other common
screens from the fish protection point of view. It also has
most of the drawbacks, including probability of fish
impingement, the need for high pressure sprays to remove
fish and debris and the need for a very large screen
structure to limit screen approach velocities to those now
being considered for fish survival.
Miscellaneous Mechanical Screens
Water treatment plants, sewage disposal facilities and
various industries requiring service water employ many other
configurations of mechanical screens, strainers and filters.
Many are designed for much smaller water flows than are
required for powerplant circulating water systems. As with
most of the screens described in this section they were
designed specifically to produce screened water* not to
protect fish.
Fish Handling and Bypass Facilities
In addition to the screening device, other types of systems
can influence the design of intake structures. The need for
fish bypass systems in conjunction with some of the
screening systems has been discussed in previous sections.
Fish handling and bypass equipment can also be used to
return viable impinged fish back to the waterway.
Relatively little work has been done on developing these
facilities for incorporation into existing industrial
intakes. Most of these types of facilities have been
installed at irrigation diversions operated by the U. S.
Bureau of Reclamation and the States of California, Oregon,
Washington and Idaho,s« A great deal of work has been done
in the Pacific Northwest in diverting salmon around
hydroelectric impoundments. .
Fish bypass and handling facilities of interest include
following:
fish pumps
the
103
-------
- fish elevators
- crowding devices
- bypass conduit
- modifications tq vertical traveling screens
Fish Pumps
Fish pumps have been used for many years. The rotary type
of pump with open or tladeless impellers seem to cause the
least amount of damage to fish. However, all rotary pumps
are not necessarily suitable for pumping all types of fish..
The use of hydraulic eductor pumps was thought to be ideal
for fish pumping. However, fish passing through such
eductors encounter high velocity jets and are evidently more
frequently injured by such encounters than they are by
passage through mechanical pumps »3. Reference HI reports
high mortalities and unsatisfactory performance from eductor
pumps.
Fish Elevators and Crowding Devices
Several types of bucket elevators have been tested in
elevating fish on a batch rather than a continuous basis.
One such system was tested at the Tracey Pumping Station by
the National Marine Fisheries Service in conjunction with
the horizontal traveling screen. This system is shown in
Figure. III-ftO. The fish are first concentrated over the
lower bucket by use of a crowding device and then raised and
dumped into the fish trough for bypass. This type of system
might be quite useful at intakes where fish might congregate
in quiescent zones created by such things as curtain walls
and other intrusions into the screen channel.
A recently patented (U.S. Patent No. 3,820,342) fish ejector
system is planned for incorporation in" the new generating
units at the San Onofre nuclear powerplant (unit 2 and unit
3), a coastal installation. The system has been tested at
the Redondo generating plant. The fish ejector system is
designed to remove fish from a moving stream of water by
attracting or directing fish away from the main flow into a
quiet zone where the fish are trapped and subsequently
removed to another discharge stream for return without
injury. Intermittent removal of fish can be accomplished by
means of the addition of water to the trapping compartment
causing discharge of fish above an overflow weir. A screen
may be raised from the floor of the compartment to cause the
104
-------
6.1 M(20')
BASKET
t
SCREEN
FLOW
FISH TROUGH
2-1 M WIDE
2.1 M DEEP
SCREEN WASH BAR - SINGLE BAR
FIGURE 111-40 FISH BASKET COLLECTION SYSTEM
705
-------
fish
weir.
to rise to the water level adjacent to the overflow
Fish Bypass and Transport Facilities
After being concentrated and removed from the screen well or
by other means of taking the fish away from in front of the
screen (such as providing slot openings on each side of the
screen with flow from in front of the screen going into the
slots giving the fish a means of egress) the fish require a
means of conveyance back to a hospitable environment in the
waterway. The design of the bypass system should minimize
the time that the fish is out of water and insure safe and
rapid return to the waterway at a location sufficiently
removed from the intake to prevent the recirculation of fish
and reimpingement. The bypass of fish into the circulating
water discharge may cause damage because of thermal shock
effects. Once the fish have been raised to an elevation
above that of the waterway they can be discharged to a
trough or pipe for gravity return to the waterway. Care
must be taken in the design of the fittings and elbows of
the discharge conduit to prevent undue stress on the fish,
which may include shock or exhaustion as well as physical
injury. Furthermore, discharge of fish should be made to a
hospitable environment. Considerable experience in
designing and operating long fish bypasses for both upstream
and downstream migrant salmon has .been obtained in the
Pacific Northwest. The technology exists for these types of
systems. Where conditions do not permit direct hydraulic
conveyance, fish can be trucked back to the waterway.
Trucking fish over long distances does not seem to cause
unacceptable mortalities. Both trucking and airlift have
been used for seeding waterways with fish. Reference 13 has
some suggested criteria for trucking fish.
Modification To Existing Traveling Water Screens
The fish bypass facilities described above were intended to
remove fish from the intake structure to prevent
impingement. An interesting example of modifying an
existing traveling water screen to bypass impinged fish is
described below.
The installation is a major nuclear station on the eastern
seaboard (plant no. 5111). The station is located above the
river and 2.7 kilometers (1.7 miles) from the intake. Water
is pumped from the river into the "high level" canal from
which it flows by gravity to the screens located at the
plant. Apparently juvenile fish pass through the pumps and
106
-------
become entrapped in the canal for subsequent impingement on
the screens. The first modification made was to connect the
screen waste flow to the plant discharge canal using a US cm
(18") polyethylene pipe. Tests made on the system in this
condition showed that this transport System minimized
mortality when the screens were operated continuously during
the cold water period but that damage was above acceptable
levels during the summer,, Mortality was primarily caused by
high screen wash water pressure and by recycling of fish at
the air-water interface of the screen front. it was
concluded that "recycling1' was a higher mortality factor in
the summer than in the winter because the more active fish
would flip back into the water after the screen basket
cleared the water surface and be reimpinged. This would be
repeated until the fish were dead or weak enough to remain
on the narrow lip until the basket reached the wastewater
stream.
The modifications are shown schematically in Figure 111-41.
They consisted of bolting a 10 gauge steel trough on the lip
of the conventional screen baskets. The troughs were posi-
tioned to maintain a minimum of 5 cm (2") of water depth
during the time of travel between the water surface and the
head shaft sprocket. The new screens are designed to be
continuously operated, thus reducing the time of any
possible impingement of fish on the screen to two minutes or
less.
The screen wash system was also modified to minimize damage
caused by the standard high pressure jets. As the screen
travels over the head shaft sprocket, the fish will be
spilled onto the screen surface. On further rotation, fish
will slide down the screen and be deposited into a trough of
running water for transport back to the river away from the
intake structure. A low pressure screen wash system has
been incorporated into the design to aid in removing
crustaceans and returning them to the river.
Since these modifications are only now being installed at
the plant, no data on the performance of these modifications
are available. No prior model testing was performed and a
prototype will be used to verify the capabilities of the
system. If reasonable efficiencies in bypassing fish safely
are obtained, this type of system might be utilized to
modify other intakes where impingement is a problem. The
system could be installed on most existing conventional
intakes, and the cost is roughly 3056 of the intial screen
cost plus the cost of the bypass line. The intake is not
substantially changed.
107
-------
LOW PRESSURE JETS
69-140 KIM/M2
,:OR FISH REMOVAL
TWO DISCHARGE . J_J
TROUGHS S i
\_7
Ir
C
C
t:
^? +
•*~~
~
i
j.. „
"1 .— • ' LJI/^LJ DDCCCIIPP IPTQ
i— • " nlori rnboQUISt Jt lo
550 KN/M2
FOR DEBRIS REMOVAL
3 (BEING LEFT OUT AT SURREY
1 WHICH HAS OTHER SCREENS
,j DOWNSTREAN)
^ I-LUW
i c~^
H, ..
.
r — FISH FALL
\ SCREEN
SECTION
\V -.,
SCREEN FACE
FRONT OF BASKET
HIGH TO KEEP
FISH IN
10.5 CM
(A POOR FEATURE)
FISH REMOVAL
DETAIL
BASKET DETAIL
FIGURE 111-41 MODIFIED VERTICAL TRAVELING SCREEN
108
-------
One disadvantage of this system may be a lack of acceptance
on the part of some of the regulating agencies. A problem
was previously noted regarding discharge of debris after it
has been removed from the waterway. As can be seen from the
figure, there is no way to avoid discharging a portion of
the debris in the fish bypass channel. Stringent
restrictions on the discharge of debris may prevent the use
of this system at many locations.
Intake Designs
In addition to special biological considerations, the size
and shape of an intake structure should be determined to a
large extent'by the following factors:
The quantity of intake flow
The type and amount of debris
The type of screening system used and
approach velocity
allowable water
The relationship of the intake to the water source
Miscellaneous factors such as need for storm protection,
avoidance of excess sedimentation, ice control
Since most existing powerplant intakes employ the
conventional traveling water screen they will be referred to
as "conventional" intakes, implying that they are equipped
with such a screen.
Conventional Intakes
There are three general classifications of conventional in-
takes based on the relationship of the intake to the water
source. These are as follows:
Shoreline intake
Offshore intake
Approach channel intake
Shoreline Intake
The most common intake arrangement is the combination of
inlet, screen well and pump well in a single structure on
109
-------
the edge of a river or lake. The best designation for this
installation is "pump and screen structure", to clearly dis-
tinguish it from individual structures also commonly used.
A plan view of this type of structure is shown in Figure
III-12. A cross section of the shoreline structure is shown
in Figure 111-43. Note that the water passes (in order) the
trash rackr the stop log guide and the traveling water
screens on its way to the pumps. This type of arrangement
is used where the slope of the river bank is relatively
steep and there is relatively little movement of the water
line between high and low water. A variation of shoreline
intake design is shown in Figure III-14. Here a wall is
used to insure drawing in of cooler lower strata waters.
Walls used primarily to protect trash racks and screen from
logs and ice can also be used to draw in cooler water.
Offshore Intake
.The offshore design separates the inlet from the pump well.
This type of intake is used where there is a significant
lateral movement in the waterway between high and low water
and where there is a particular technical or environmental
reason for utilizing the water supply at a distance from
shore. Figure 111-45 and 111-46 show two similar concepts
of such an intake. The design shown in Figure 111-46
employs a siphon. The term siphon here refers to a gravity
pipe placed above the level of the water and thus flowing at
less than atmospheric pressure. The provision of fine
screening facilities at the conduit inlet offshore is often
impractical because of construction difficulties, because of
•the navigational hazards it presents or because of
difficulty of access- for operation and maintenance.
Therefore, the fine screens are usually located on shore as
shown in both Figure 111-45 and 111-46. Flow velocities are
commonly rather high (about 1.5 to 3.0 mps) in the inlet
pipeline to reduce its cost. Most species of fish would not
be able to escape entrapment in the system after entering
it. Since offshore intakes can have screens onshore,
diversion weirs or crowders can be used as a second line of
control to remove fish prior to possible interaction with
the screen.
Approach Channel Intake
In this type of intake, water is diverted from the main
stream to flow through a canal at the end of which is the
screening device. This type of intake is shown in Figure
III-47. Channel intakes have often been used to separate
no
-------
HORELINE
LAKE
OR RIVER
V
r
\
PUMPS
PIPELINE
WATER SCREENING
FACILITY
PLAN
Figure 111-42 SHORELINE PUMP AND SCREEN STRUCTURE
111
-------
ii 1111 in i mi am
' i'' i'
UJ
cc
a
cc
01
01
cc
a
1
a.
1
g
H
01
>
O
a
Ol
cc
D
O
-------
ROTATING SCREEN y
TRASH BARS _, /
H.W.
v
L.W.
XT-
SKIMMER WALL ;£n-
: LOW LEVEL -
; INTAKE ~-
/ .
v ^^/^
7 /
/
/ ^ «*''•*.. C
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77>VAV7 VW y^f- •' 'I
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t
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z
_
PUMP
TO PLANT
-d
-EC
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* *' < V,'-i x*-.f» •>•'«
6
4
J
i'
^^iTj
£
>-&-
FIGURE 111-44 PUMP AND SCREEN STRUCTURE WITH SKIMMER WALL
773
-------
CIRC. WATER
PUMP
ROTATING SCREEN
TRASH BARS
TO PLANT
HE AD LOSS IN
INLET PIPE
FISH CAP
(VELOCITY CAP)
i
*•
7P-
' FIGURE 111-45 PUMP AND SCREEN STRUCTURE WITH OFFSHORE INLET
174
-------
01
a.
O
a.
DC
111
X
O
O
cc
X
UI
u.
O
cc
Q.
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•<*
111
cc
D
O
LL
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115
-------
OUTFALL
GENERATING
PLANT
LAKE
^SlLliLkl^
^^^
\
,'
• /
'/
' /
f /
V-
\
/
/ ~
'/
'/
'/
t*
'/
//
V
APPROACH CHANNEL INTAKE
A
APPROACH CHANNEL INTAKE
FIGURE 111-47
116
-------
the plant intake and outfall for i the control of
recirculation effects, to permit location of the pump
structure where it can more easily be constructed or to
reduce total system friction losses and costs by replacing
high friction, high cost pipe with low friction, low cost
canals. It may also be used to remove,the intake from the
shoreline for aesthetic reasons, which are discussed
elsewhere. However, fish will tend to congregate in these
approach channels and thus increase the possibility of
entrapment and predation at the screens. A modification of
the approach channel concept is shown in Figure 111-48,
where the screen structure has been placed at the entrance
to the channel and becomes essentially a shoreline intake,
without the fish entrapment hazards inherent in the channel
scheme. However, care must be taken with the shoreline
intake to avoid velocities which could increase impingment.
In certain cases approach channels may be helpful to
achieving uniform approach velocities.
Conventional Intake Design Considerations
In addition to special biological considerations, other
important considerations in the design of conventional pump
and screen structures are the following:
Water level variations
Inlet design
Screen placement
Screen to pump relationships
Flow lines to the pump
configuration
Ice control provisions
and the pump chamber
Access to the structure for operation and maintenance
Inlet safety design considerations will be different for
each of the three classifications of conventional intakes.
For the shoreline intake an important consideration is to
avoid significant protrusions into the waterway. This is
shown diagramatically in Figure III-49. The top sketch
shows an example of undesirable intake design where the side
walls of the intake protrude into the waterway and create
eddy currents on the downstream side of the intake. Fish
are sometimes found concentrated in these areas, a situation
117
-------
Lake (
- r
River I
Water Screen Facility
(Example 2)
"IChannel
O-
O-
Pump Well
SCREEN LOCATION - CHANNEL INTAKE
FIGURE TIl-48
JIB
-------
RIVER FLOW
SCREENS
- PROTRUDING
WALL
SHORELINE
AREA OF WATER EDDIES
POOR DESIGN
RIVER FLOW
PUMPS
GOOD DESIGN
FIGURE 111-49 SHORELINE INTAKE
119
-------
which may increase the possibility that they will become
entrapped in the intake. The bottom sketch shows a more
suitable design with no portion of the intake protruding
into the flow. Of course, this would not be significant at
intakes drawing water from a lake shore location where cross
flow velocities are negligible.
Screen Placement
Most conventional intakes are designed with the traveling
water screens set back away from the face of the intake
between confining concrete walls. As shown in the top
sketch of 111-50, this creates a zone of possible fish
entrapment between the screen face and the intake entrance.
Small fish may not swim back out of this area. The bottom
sketch of the same figure shows an alternative screen place-
ment with screens mounted flush with their supporting walls.
The trash rack facility is so designed that there is an open
passage to the waterway directly to both left and right of
the screen face. In this design, there is no confining
screen channel in which the fish can become entrapped.
Figures 111-51 and 111-52 show two recent designs of "flush"
mounted screen structures. The first is the screen and pump
for a major fossil-fueled powerplant in the Northeast (plant
no. 3601). Figure 111-52 is the pump and screen structure
for a major fossil-fueled powerplant on the west coast
(plant' no. 0610). Note that the screens are mounted flush
with the shoreline in each case and that fish passageways
are provided in front of the screens. In these designs
there is no provision for stop logs to permit dewatering the
screen wells. Extending the screen support walls to provide
stop log guides would defeat the "flush" mounting principle.
Where channel sections leading to the screens cannot be
avoided due to some unusual condition, proper design of the
screen supporting piers can reduce the fish entrapment po-
tential of the area. This design consideration is shown in
Figure I11-53. In Figure III-53A an example of incorrect
pier design is shown. The pier which protrudes into the
flow presents a barrier to fish movement. They cannot make
the turns required to escape the screen. Figure III-53B
shows a much more suitable design. With the extended
portion of the pier eliminated, the fish can move sideways
and rest in the relatively still water near the face of the
pier.
Maintaining Uniform Velocities Across the Screens
120
-------
TRASH BARS
SHORELINE
TRASH BARS
SHORELINE
SCREEN WELLS
: (FISH ENTRAPMENT AREAS)
j: -r
i -;TR/
!- sc
TRAVELING"
SCREEN !;
PUMPS
CONVENTIONAL SCREEN SETTING
"f^'Q---'!
.-"FLUSH" MOUNTING OF SCREEN
r
-
V
•--•
i
— i-— _...
ris
. .
-_\
-•
Q^,,^,,,,,^^,,^^^
FISH PASSAGE / • -h- >
/ •'
/ '
>f
TRAVELING
< SCREEN
PUMPS
MODIFIED SCREEN SETTING
Figure 111-50 FLUSH MOUNTED SCREENS - MODIFIED
AND CONVENTIONAL SCREEN SETTINGS
127
-------
SCREEN
t
/HNC
- PIER
UNDESIRABLE
FISH CANNOT
MAKE TURN IN
THIS AREA
FIGURE A
UNSATISFACTORY DESIGN
v-
-.-4r'
SCREEN r
J
1
*
• * ~;
-4,.,
t
FISH REST
IN THIS AREA
t
FIGURES
IMPROVED DESIGN
FIGURE IN-53 PIER DESIGN CONSIDERATIONS
124
-------
It is essential in good screen structure design for
environmental protection to maintain uniform velocities
across the entire screen face. When flow is not uniform
across the screen, the potential for fish impingement is
increased.
Figure 111-54 tabulates a typical run of a model test series
made for a major plant in the Northeast (plant no. 3601).
The variation in velocities is evident. Flow distribution
in many existing intakes is much less uniform than indicated
in Figure 111-54.
There are several ways in which a non-uniform screen
velocity can be created. Figure 111-55 illustrates some of
the factors which create non-uniform velocities in the
screen area. Sketch A of Figure III-55 shows the condition
when water approaches the screen structure at an angle.
Flow tends to concentrate at the downstream side of the
water passage entrance and in some cases may even flow
backwards on the upstream side. Sketch B shows the effects
of walls projecting into the water passage. Walls similar
to that shown here are frequently used to reduce the intake
of surface debris or to confine the entering water to a
lower and normally cooler strata. The result is not only
the creation of non-uniform velocity conditions at the
screens, but also the creation of a dead area where fish may
become entrapped. They will not usually swim back to safety
under the wall. Sketches C and D show the effects of pumps
or downstream water passages so located that water is drawn
from a limited horizontal or vertical strata as it passes
through the screens. Pumps or gravity exit pipes may be too
close to the screen or may be offset from the screen^center.
Hydraulic Institute standards recommend a minimum distance
from screen to pump, but this distance is established for
suitable pump performance, not for best utilization of the
screen area.
The obvious result of the non-uniform distribution of flow
through the screens is the creation of local areas of flow
velocities much higher than the calculated average design
velocities* Entrapment of fish is thus potentially
increased.
One basic consideration in initial layout of the intake is
the matching of the pumps to the screens. Figure 111-56
illustrates four intake variations to accommodate pumps of a
wide range of sizes. Sketch A is an intake for several
small pumps served by one screen. This type of arrangement
is dictated when the individual pump capacities are smaller
than the minimum sized screen employed . Sketch B is a one
125
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VELOCITY MEASUREMENTS (IN FT/SEC) AT ENTRANCE
OF PUMP BAY NO. 3 FOR THE FOLLOWING CONDITIONS:
PUMPS 1,2 AND 3 IN OPERATION: 2FT/SEC RIVER
FLOW WITH THE WATER LEVEL OF 0', AND FULL WALL
OPENINGS.
FIRST CROSS-SECTION (UPSTREAM FROM THE TRASH-RAKE)
NEAR BOTTOM
MID-DEPTH
NEAR SURFACE
(a) (b) (c) (d) (e) (f)
0.34| 1.06\ 1.12/ 0.74\ 0.95\ 0.75*
0.454 0.93 f 1.02\ 0.89\ 0.75^t 0.83/
0.57\ 0.674 0.33/ 041* 0.31/ (NIL)
SECOND CROSS-SECTION (IN THE FISHWAY)
NEAR BOTTOM
MID-DEPTH
NEAR SURFACE
(a) (b) (c) (d) (e) (f)
0.391 0.57t 0.994 (NIL) 0.754 0.734
(NIL) 0.574 0.951 (NIL) 0.90J 0.804
0.624 0.68/ 0.87-*-0.77-^0.95-*-0.72-*
THIRD CROSS-SECTION (DOWNSTREAM FROM THE SCREEN)
NEAR BOTTOM
MID-DEPTH
NEAR SURFACE
(a) (b) (c) (d) (e) .(f)
0.68f 0.844 0.80J 0.60f 0.744 0.67 4
0.804 0.954 1.064 0.674 0.804 0.81 4
1.20f 1.01J 0.47f 0.634 0.634 (NIL>4'
•?1 H
. WATER
JMP
' f ,»».••» iO,
L^«t,l.-*.\i*.#
BAY* 3
:V*,t ^ I-'.*/
TRAV.
SCREEN
1 *".*< \*»- • '
i
i
• \
\
i
;, i LU
* •* CD
T3 - ,w
111
u
fa
E
FIGURE 111-54 SCREEN AREA VELOCITY DISTRIBUTION
126
-------
PUMPS
FISH ENTRAPMENT
AREA
ij
A
. V
B
TO PUMPS AT PLANT i
........2._ '• v
i
s'Z
' • oi
: HI
DC
z
LJJ
•8
UJ
8, - j .
Ull i ,.
•• g s ^ —
o S
'
!
\
1
U. lil j
u- z
1 UJ _ _
<7-;^,-.//..-
"-'TO PUMPS!
i
FIGURE 111-55 FACTORS CONTRIBUTING TO POOR FLOW DISTRIBUTION
127
-------
Screen
Pumps
Screens
O
Pumps
B
Screens
O
umps
O
Screens
PUMP/SCREEN RELATIONSHIPS
FIGURE 111-56
O
I
O
Pumps'
128
-------
pump - one screen arrangement common for medium size pumps
up to about 100,000 gpm. Beyond this pump size the physical
limitations on the screen size (14 foot trays or baskets are
the maximum commercially available) requires the use of
multiple screens per pump. Sketches C and D illustrate
possible combinations. Care must be taken to locate the
screen with respect to the pump in a manner which will
properly utilize the entire screen surface. If a very low
screen velocity is required for a very large pump
installation, the length of structure required for the
screens may be greater than that which will be hydraulically
suitable for the pumps. Such a requirement could result in
the configuration shown on Figure III-57.
Pump Runout and the Effect on Screen Settings
Sketch A of Figure 111-58 shows a typical one screen per
pump intake. If the screen is sized for the design flow of
the pump, the screen velocities will substantially increase
during periods when only one pump is in operation. This is
the result of the "runout" characteristics of the pump which
tends to pump more water as the total system flow and head
losses decrease. As much as HQ% flow increase might be
expected. Operation in this manner is common in those areas
where winter water temperatures are much lower than summer
temperatures. We may then expect an increase in screen
velocity during those cold water periods when lethargic fish
might be least able to resist the flow. Consequently, if
this type of setting is used, the screens must be designed
for the expected runout flow of the pump.
An alternative to the individual bay setting shown in Sketch
A is to place the pumps as shown in Sketch B of Figure III-
58. In this case, an open chamber is located in the side
wall between the pumps and the screens. The operating pump
may thus utilize a part of the screen area normally used for
an adjacent pump. Field and laboratory tests show that only
a small part of the adjacent screens are effectively
utilized in this situation, but that a small part will be
sufficient to compensate for the increase in pump flow if
the screens and pump are properly located.
An intake of the latter type will be larger and more costly
than the former. Maintenance procedures may be complicated
by the fact that the central bay cannot be dewatered and
also the dewatering of individual screen and pump bays be-
comes more complex.
Design of Ice Control Facilities
129
-------
SCREENS
CO
CO LL)
s *
CM ^
s .8
_ cc
S ui
in j-
1 I
CO
PUMPS
3 BAYS© 3.66 M
<—«-..- • .._ i
PLAN
FIGURE 111-57 PUMP AND SCREEN STRUCTURE FOR LOW INTAKE VELOCITIES
130
-------
o
B
EFFECT OF PUMP RUNOUT
FIGURE Hi-58
131
-------
Most powerplant intakes located in the northern latitudes
must have some provision for ice control during the winter
months. Sheet ice and "frazil" ice ("needle" ice) can cause
flow blockage at the intake. The system most frequently
used to control the ice problem is the recirculation of a
portion of the warmed condenser water back to the intake.
Figure 111-59 shows a cross section of a powerplant intake
with the ice control header and discharge ports located up-
stream from the screens. The sketch shown is for a major
nuclear plant located on the Mississippi (plant no. 3113).
A variation of this method would be to recirculate only
intermittently to minimize retention of fish "attracted" to
the intake area by the warmer water used for ice control.
Other ice control systems that have been tried have been
less successful. In particular, several attempts to use an
air bubble curtain (similar to that described in the section
on behavioral screening) to control ice have not been
completely effective. Other methods of ice control are to
place the intake well below the water surface, or, for sheet
ice, to agitate the water surface with propellers or similar
devices.
The problem with the use of the recirculation system for ice
control is that it has been shown that fish concentrate in
warmer water in the winter time, thus increasing their
possible interaction with the screen. It has also been
shown that fish are lethargic in the cold water periods and
cannot swim well against the intake flow. These two factors
can combine to make the traditional warm water recirculation
system less than desirable from an environmental standpoint.
NonrConventional Intakes
Non-conventional intakes involve the use of methods for
separation of water and debris other than the screening
devices and/or screen mountings previously mentioned. The
non-conventional intakes described in this section include
the following.:
- Open setting screen
- Filter type intake
- Perforated pipe intake
- Radial well intake
132
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133
-------
Behavioral Intakes
Open Setting Screens
Figures III-25 and 111-38 show two screens which have been
mounted on platforms and connected directly with the pumps
which they serve. One is the double entry, single exit
vertical traveling screen, the other the double entry drum
screen of European design. Both of these screening systems
have open water completely around them, thus eliminating to
a large degree possible fish entrapment areas. A second
advantage of these systems, and the original purpose for
which they were developed, is the elimination of costly
concrete screen wells. Most • such installations would
require some type of trash rack protection which is not
shown in the figures.
Flow distribution through the screen faces may not, however,
be suitably uniform. The areas nearest the inlet to the
pumps will tend to have higher flows and velocities and may
therefore result in undesirable fish impingement. This ob-
jection might be overcome with internal dividers and
increased screen sizes, but no information is available that
indicates that such measures have been utilized.
A similar system is being used at plant no. 1229 located on
the Southeast coast. The system has performed reliably for
several years.
Filter Type Intake
Many types of filter intakes have been developed on an
experimental basis and some have been installed in
relatively small scale applications for powerplants. The
essential feature of all these schemes is the elimination of
mechanical screens. The water is drawn through filter
media such as sand and stone. Such an intake is capable of
being designed for extremely low inlet velocities and can be
effective in ' eliminating damage even to small fish.
Planktonic organisms can also be protected to some extent.
Figure III-60 is a sketch of a stone filter in use since
late 1971 to screen makeup water for a large powerplant in
the Northeast (plant no. U222). The sketch shows the
original filter. It has since been modified several times
in attempts to improve its performance. It still has a
tendency to clog and cannot yet be considered reliable.
Figure 111-61 is a somewhat more complex design developed
134
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FILTER CAPACITY 25,000 GPM
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3 PUMPS 12,5000 GPM EACH
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PUMP STRUCTURE
DISTRIBUTION
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FIGURE 111-61 INFILTRATION BED INTAKE - PLANT NO. 5309
136
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but not used for the makeup water of a large
the Northwest (plant no. 5309).
powerplant in
A preliminary filter design has been developed for the
21 «S f?;rculatin9 water flow to serve a major powerplant in
crltfJn^f - This system employsprecLrcon-
««»M J Km?dule? Xn Seven ^P^ate filter sections, each
capable of being isolated for maintenance. The entire
filter complex would be about (450 x 260 feet) in plan.
Another filter system concept which has been used with some
success in relatively small intakes is the "leaky dam" which
consists simply of a stone and rock embankment surrounding
™^HP^P structure- Water must flow through the "dam" to
reach the pumps. The dam thus acts as a screen. Very low
water passage velocities can be achieved and the danger of
fish impingement is reduced. Very small fish can, however
pass through the openings in the stone. A major proSemlSr
2£L-nYS 5 in. waters containing suspended matter would be
SiSSi^i Practical backwashing facilities have not been
developed. An intake system of this type has been operated
at powerplant no. 5506 since late 1972. It haT beSn
reported be 70-75* effective in screening out fish.
Although these filter intakes would appear to be ideal from
an environmental point of view, they have mny
SJiSl antages. The clogging problem is foremast, in turbid
waters such clogging would rule out the filter use
Backwashing facilities will be needed in even relatively
clear water. The backwashing procedure will temoorarilv
«!? -^ tT^ia^y.°f ^s^earn waters and ttus ma^S ll
conflict with limitations on turbidity. To date no laroe
scale filter system has been developed and proved rlliablS
in operation. The cost of such a system will be
* COI«Parabll convStiona?
Perforated Pipe Intake
^T Perforated pipe intake is shown in Figure 111-61
and 111-62. This concept has been discussed in detail under
"fixed screens" elsewhere in this report. The figures ^hSw
a preliminary design being considered at this time for the
IS 6£P ?Kter SYStem °f a major steam electric powerplant in
to hanST^f hJPl!?ti?0- 53°9)- The ^ncept c^n bePexpanded
2? onn ™ substantially greater quantities of water than the
25,000 gpm to be passed through the illustrated intake. The
137
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previous discussion includes a review of the advantages and
disadvantages of this scheme.
Radial Well Intake
The radial well intake is an infiltration type utilizing
£?£?~i. H*-Place Pervious material as contrasted with the
artificially prepared filter beds discussed above. Slotted
pipes are jacked horizontally into sand and gravel aquifers
beneath the river bed. These pipes are connected to a
common pump well. This is an intake which has been
frequently used for obtaining highly filtered industrial and
municipal water. The radial well intake is shown in Figure
111-63. This type of intake can only be successful where
suitable water bearing permeable material is found It
provides a degree of screening which far exceeds the
requirements for cooling water supplies. it has the
advantage of being the most environmentally sound intake
system because it does not have any direct impact on the
waterway. it would be competitive in cost with conventional
small intakes of the same capacity. However, for very large
capacity requirements, several individual widely scattered
cells would be required and the cost would be substantially
greater than for a conventional intake. Radial well intakes
rel? blSen in Service for over 35 vears an<3 have been
Behavioral Intakes
The wide variety of behavioral intakes has been discussed
elsewhere in this report. They represent a substantial
departure^ from "conventional" screen facilities. Such
intakes include horizontal screens, louvers, air bubbles,
sound, etc., and combinations of these features with each
other and with more conventional facilities.
Conventional intakes themselves can be modified to take
advantage of fish behavior. For example, angling
conventional screens to the incoming water flow can guide
tish to bypasses in the same manner as the horizontal screen
and the louvers. Figure 111-64 is a sketch of such an
installation. The total facility would be substantially
more costly than the more conventional setting due to the
orientation of the screens and the need for providing fish
bypass facilities (possibly including fish pumps and
auxiliary water cleaning equipment). Hydraulic studies can
be made to develop guide walls both in front of and behind
139
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Plan
Pumps
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Ground
Water Level:
Reinforced
Concrete
Caisson
River ... :
Sand and Gravel Aquifer
Perforated Screen
' Pipe Jacked into Aquifer
^—"-^ -------- - --—-;->
Section
Figure 111-63 RADIAL WELL XNTAKE
140
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TRASH BARS
, ... . 1 , -, , j ......... , , . ,;-,.;
"
i;
CONVENTIONAL TRAVELING •
SCREEN ("FLUSH"MOUNTED);
\ \\/^ FISH MOVEMENT "J
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FISH PUMP —
FIGURE 111-64 ANGLED CONVENTIONAL TRAVELING SCREENS
141
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the screens to assure
screens.
Circulating Water Pumps
a reasonably uniform flow through
Mechanical stress of circulating water pumps can be the
primary contributor to mortality of organisms withdrawn from
the cooling water source. High mortality has been observed
in cooling water systems operating during periods of no heat
load.f9
Pumps used in condenser cooling water systems of steam-
electric plants typically range in capacity from about
20,000 gpm to 250,000 gpm, and there are usually two to four
pumps for each generating unit. Circulating water pumps
normally have axial or mixed flow impellers and are of
either the wet pit or the dry pit type. Smaller pumps used
in steam electric plants may be of the centrifugal type.3*
Rotating speeds may normally range from 150 rpm for the
large, low head pumps to 900 rpm for the lower capacity
range. In once-through systems, total dynamic head may
range between 20 and 50 feet. In closed-loop systems with
cooling towers, higher pumping heads are required. The pump
setting and design must be such as to avoid cavitation for
all operating conditions. Water velocities at the pump
discharge may range between 8 and 12 ft/sec.3*
Existing Structures
Many existing intake water structures fall under the
definition of a cooling water intake structure.
Consideration of the factors discussed in this document will
be required for existing as well as new structures. It is
possible, however, that the cost of modifying an existing
intake structure to comply with all of the best technology
discussed in this document may exceed the cost of designing
and constructing a new intake structure to comparable
standards.
In determining the "best technology available" that is
applicable to an existing structure^ the degree of adverse
environmental impact should be considered. An existing
structure may be acceptable despite the fact that it does
not conform in all details to the criteria recommended in
this document if, as a result, environmental damage is
minimal. Such an evaluation .also is to be on a case-by-case
basis and, as in the case of a new structure, the burden of
proof is on those owning the structure. An existing intake
structure is a structure that was in operation or upon which
142
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o?nn^^?.!!a^C°^e2fed as °f December 13, 1973, the date
New structures can be expected to incorporate the most
SnvfJonl^0?^1091031 meth°ds Bailable to miniSle adverse
environmental impacts. Thus, new structures are expected to
conform to the criteria discussed in this W
143
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SECTION IV
CONSTRUCTION
Introduction
The adverse environmental impact associated with the
construction of cooling water intake structures results from
three factors. The first of these is that the intake
structure may occupy a finite portion of the bed area of the
source water body. To the extent that this occurs, there
will be a loss of potential habitat and a displacement of
the aquatic populations that reside at that location. In
addition, modifications to a larger area surrounding the
specific intake location resulting from construction
activities and changes in existing topography can create
permanent disruptions in the biological community.
The second factor is the impact on the ecosystem of
increased levels of turbidity resulting from the
construction of the intake structure and any associated
inlet pipes and approach channels. Turbidity levels can
also be increased as the result of erosion of inadequately
protected slopes of excavations and fills created during the
construction operations.
The third factor concerns the location of disposal areas for
the materials excavated during construction. If spoil dis-
posal areas are located within the confines of the source
water body, further permanent disruptions of the existing
aquatic species can result. If these spoil banks are not
adequately stabilized, increased levels "of turbidity may
persist for an indefinite period. Adequate protection and
stabilization of spoil areas located above the waterline are
als© required to prevent long term erosion of these
materials which can contribute to increased turbidity
levels.
Of the three factors mentioned above, the first will not
significantly impact the environment in most cases . The
remaining two factors can create serious short term and long
term problems if hot properly controlled.
Displacement of Resident Aquatic Organisms
The impact of the physical size of the intake structure on
the displacement of the resident biological community is a
function of the size of the intake. Offshore intakes which
require long conduits placed in the waterbody or wetlands
145
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will be more disruptive to the resident species than
shoreline intakes. The species that will normally be most
effected by the construction of the intake structure are the
benthic organisms. The impact of construction activities in
this regard is expected to be small since in no case will
the intake structure occupy more than a small percentage of
the total area of the source. All water sources should be
able to adjust rapidly to the loss of habitat area and to
reproduce the small portions of the important organisms
lost. If the locational guidelines proposed are followed,
the impact of this aspect of intake structure construction
will be minimized.
Turbidity Increases
Increased turbidity can result from the construction of
intake structures in several ways. First, increased
turbidity can result from physical construction activities
conducted below the water level of the source. Such
activities as dredging, pipe installation and backfilling,
and the installation and removal of coffer dams and related
facilities can create significant increases in turbidity
unless these activities are carefully controlled. The
turbidity created by the physical construction of intake
structures will normally be limited in duration to the
extent of the construction schedule. The impact of this
type of turbidity increase on the source ecology is
dependent upon the particle size distribution of the
sediment, the sediment transport characteristics of the
source, and the location of the important organisms with
.respect to the intake structure construction activities.
There are a number of construction techniques that can be
employed to reduce the turbidity increases associated with
these activities. Excavation and dredging activities can be
conducted behind embankments or coffer dams to contain
potential sediment discharges. Care can be exercised to
limit the turbidity increases due to the construction and
removal of these facilities. Onshore construction can be
performed with natural earth plugs left in place to prevent
the discharge of material to the source. Construction can
be scheduled to take advantage of low water periods and
periods of reduced biological activity in the source. Some
sources will expose a large portion of the flood plain under
low water conditions allowing much of the intake structure
to be constructed in the dry area. Construction can also be
scheduled around important spawning periods, feeding periods
and migrating periods to reduce impact to these functions.
146
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The control of dewatering activities can also be important.
The dxscharge of soil materials from dewatering activities
can be limited by the use of holding ponds or filtration
equipment prior to discharge of this water to the stream.
All material excavated or dredged in the construction of
intakes should be placed above the water line where
possible. The laying of conduit can be scheduled to
minimize the amount of time that the trench is open As
soon as the conduit is placed, the trench can immediately be
backfilled and the surface of the trench smoothed over to
prevent erosion of the trench materials.
Long term turbidity increases can result from the
entrainment of material from spoil areas located either
below the waterline or erosion of material placed above the
waterline. in addition, erosion of excavations and fills
that are permanent parts of the intake can also add
turbidity that will persist long beyond the completion of
construction activities. Adequate stabilization of these
i 1i?11 may necessitate rip-rap slope protection and seeding
of fill areas. ^
Disposal of Spoil
The disposal of spoil within navigable waters is controlled
by the U.S. Army Corps of Engineers. The disposal of spoil
from excavation and dredging activities can displace and
destroy important benthic organisms. The disposal of spoil
in known fish spawning, nursery, feeding areas, shellfish
beds and over important benthic populations can cause
permanent loss of important biological species.
147
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SECTION V
CAPACITY
Introduction
Any damage to organisms caused directly or indirectly by the
withdrawal of water for cooling purposes constitutes an
environmental concern pending the determination of the
significance of the damage with respect to the aquatic
ecosystem. The death rate of sensitive forms of aquatic
biota that pass through a cooling water intake structure can
approach 100 percent. However, if the cooling water flow is
small relative to the total stream flow, the 100 percent
death rate may not result in an adverse environmental
impact. Where significant numbers of critical aquatic
organisms are destroyed, the adverse impact must be
minimized. Thus, the effect of capacity with regard to
adverse environmental impact should be placed in the context
of the significance of the loss and therefore the degree of
adverse impact that results.
Since the environmental risk associated with entrainment is
related, in large part, to the volume of the stream flow
passing through the cooling water intake structure,
reduction of intake volume of flow (capacity) is one of the
most effective methods that can be used to reduce the
adverse environmental impacts of cooling water structures.
Adverse environmental impacts resulting from damage to
organisms withdrawn from the water body and directly
attributable to the capacity (volume of flow) of cooling
water intake structures may be caused by the following:
1) interaction with the intake structure
2) interaction with the cooling system
3) interaction with the discharge structure
U) interaction with the receiving water environment at
the outfall
5) exposure to chemicals added between the intake
the outfall
6) exposure to elevated temperature levels during
after passage through the cooling system
and
and
149
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These types of adverse impacts with the exception of (1) ,
can be termed "entrainment11 effects. Interaction with the
intake structure is discussed at length in Sections III and
VI of this document. All of the remaining adverse impacts
listed above, with the exception of interaction with the
receiving water environment at the outfall and temperature
effects beyond the outfall, can be termed "inner-plant"
impacts.
Additional types of adverse environmental impacts related to
the capacity of cooling water structures are those involving
damage to aquatic habitats, as discussed in Section I of
this document,,
Inner-plant or entrainment impacts affect forms of life
small enough to pass through the intake screens intact,
e.g., plankton, small invertebrates washed from the nekton,
fish larvae, pre-juveniles, and small fishes. Inner-plant
damage that may be incurred is due to velocity and pressure
differentials, temperature changes, changes in dissolved
oxygen concentrations, and the presence of biocides and
other chemicals.
The velocity of water flow increases at certain points as it
passes through a cooling system. The high velocity can
cause organisms to strike against various parts of the
system, particularly the ends of the heat exchanger (e.g.,
condenser) tube head boxes and thereby to suffer impact and
abrasion damages and shock. Velocity gradients within
system also
organisms.3S
the
can exert strong shearing forces on entrained
In an operating plant, the cooling water temperature
increases suddenly as it passes through the heat exchangers
tubes, thereby exposing entrained organisms to the potential
hazard of thermal shock. Dissolved oxygen also may be
reduced adding further stress. Chlorine may produce some
mortality or suppression of metabolic acitivity to organisms
that pass through the plant cooling system. Some mortality
of entrained organisms may result from mechanical, thermal
and osmotic stresses as the discharge plume mixes with the
receiving water environment.
Fishes
While entrainment effects also may occur in plants with
once-through cooling located on oceans and fresh water
bodies, the problem is especially important with high volume
intakes in estuaries. In these unique waterbodies a
substantial number of critical aquatic organisms are
150
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vulnerable to inner-plant and screen kills. Estuarine
species typically have 'suspended young stages that are
vulnerable to entrainment and are concentrated in limited
areas within the estuary.as It ^s the high productivity of
estuaries that supports many commercially valuable fishes
and invertebrates. For example,-it has teen estimated that
63 percent of the Atlantic commercial catch of fishes and
invertebrates is made up of estuarine dependent species.3'
Inner-plant damage may be the most serious impact of
estuarine-sited power plants with once-through cooling.3s
The potential of estuarine plants for massive kills is well
demonstrated by a study of the U.S. Environmental Protection
Agency at plant No. 2525. in 1971, EPA scientists,
estimating inner-plant kills, found that: larval menhaden
were killed on passage through the plant and that
hydrostatic, mechanical shearing forces appeared to be the
cause. The highest calculated kill was 164.5 million
menhaden in one -day—July 2, 1971. On other days in 1971,
the kills (which also involved some river herring) ranged
from seven to 28 million per day."
In most estuaries, a high proportion of important fish
species are vulnerable to entrainment and inner-plant damage
when they are young and swim weakly and are living a pelagic
or planktonic life suspended in the water. For example, 19
fish species of the James River estuary have been identified
as being subject to entrainment at plant No. 5111.3s
Calculations made of the significance of the inner-plant
kills in plants located on estuaries show a high proportion
of the total population to be affected. For example, at
Plant No. 0904, it was found that: "An impressive number of
these larvae were entrained through the plant so that by
mid-June, a total of 2.5 million or almost one-half of the
maximum larval population in (Niantic) Bay had been
entrained. If the survival of entrained flounder larvae is
low, then it is apparent that Unit 1 may do considerable
damage to the flounder, population in the area around
Millstone Point."*3
The U.S. Atomic Energy commission staff analysis for Plant
No. 3608 (Reference 8h) showed that: "...during June and
July of most years from 30 to 50 percent of the striped bass
larvae which migrate past Indian Point from upstream
spawning areas are likely :to be killed by entrainment....
In addition, large numbers of older striped bass will be
killed by impingement. The combined effect of these two
sources of mortality will decrease recruitment to the adult
population of striped bass which depend upon the Hudson
151
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Biver for' spawning. As a result, there is high probability
that there will be an initial 30 to 50 percent reduction in
the striped bass fishery which depends upon the Hudson for
recruitment."
The staff later refined the estimates using simulated rates
of flow for various years, included the effects of other
power plants on the Hudson Estuary that would entrain young
striped bass and found that as high as 6H percent of the
year's production of young bass would be killed (8h).
The striped bass (or rockfish) is threatened throughout its
range by power plants. In every major breeding area there
is now a power plant or one is proposed or probable—the
Hudson, Upper Chesapeake-Delaware, Potomac, James, Patuxent,
Sacramento-San Joaquin.35
The striped bass is among the most valuable of Atlantic
coast species of fishes, each year supplying a commercial
catch of five to ten million pounds*5 and recreational
fishery valued at around $150 -million. It is also of great
value on the. Pacific coast, particularly in the San
Francisco Bay area where it furnishes the most important
sport fishery.*s
• • • jn-
Because of the peculiarities of its life cycle, the striped
bass is especially vulnerable to damage from power plants
sited in estuaries. Throughout its range of occurrence the
species is vulnerable not only to direct damage but to
undermining of the complex web of life that provides its
food resources.35
Microbiota
All planktonic life of the water, all the suspended
microflora and microfauna, are potentially subject to the
same impacts from passage through a plant cooling system
that have been described above for fish larvae and
juveniles. However, research shows that planktonic plants
(algae or phytoplankton) and invertebrate animals
(zooplankton) are more resistant to damage than the fishes
because, with some exceptions, their populations appear to
be less affected by the shocks of plant passage. It is
important to protect the planktonic microbiota because it
supplies the foundation of nourishment for the whole chain
of life in the estuary and because it includes the young,
the larvae and juvenile stages, of valuable species of
shellfish.35 A more detailed discussion of entrainment
impacts on microbiota is given in Reference 35 and a portion
152
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of that discussion is given in the Appendix of this
document.
Reduction of Cooling Water Intake Volume
Reduction of cooling water intake volume (capacity) should,
in most cases, reduce the number of organisms that are
subject to entrainment in direct proportion to the
fractional flow reduction.35, 46 Figure V-l shows the
beneficial effect of reduced intake water volume on fish
impinged or entrained on the intake screens (8g 35) .
Intake flow volume reduction can be achieved by two basic
means: (a) maintain a non-recirculating (once-through)
cooling system but reduce flow through the system; and (b)
adapt a'recirculating (closed-cycle) cooling arrangement.
These means can be applied simply or in combination, and
continuously or interchangeably throughout the year.
In particular, the EPA Development Document for Effluent
Limitations Guidelines and New Source Performance Standards
for the Steam Electric Power Generating Point Source
Category (October 1974) should be referred to in determining
the methodology, efficacy and cost of 'a recirculating
cooling arrangement. (Reference 38.)
Since cooling systems must accept a predetermined amount of
waste heat, reduction in once-through flow volume must of
necessity be accompanied by a corresponding proportional
increase in coolant temperature rise through the system.
Figure V-2 shows the cooling water requirements for fossil-
fuel and nuclear powerplants as a function of the coolant
temperature rise. For example, the highest design
temperature rise for a powerpiant is 45°F (Plant No. 3306).
In this particular case, the relatively low cooling water
intake flow volume design for this once-through system was
created to economize on the size of pipes and pumps needed
to transport cooling water over two miles from the water
source to the plant. The intake water volume corresponding
to a «I5°F temperature rise could be about 20 to 50 percent
of the intake water volume required for power plants with a
temperature rise in the normal range (about 10 to 20°F).
Offsetting the environmental benefits of intake capacity
reduction by this means are the possible adverse
environmental impacts of the.higher temperature rise through
the cooling system with respect to inner-plant impacts and
effects of the discharge on the receiving water environment.
"Helper" cooling means are employed at some power plants to
reduce cooling water discharge temperatures to meet
153
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154
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Figure V-2 ;
COOLING WATER REQUIREMENTS FOR
FOSSIL AND NUCLEAR POWER PLANTS 48
- — NUCLEAR, • - FOSSIL,
* 33 % T * 40%
IN-PLANT LOSSES
= 5%
IN-PLANT AND
STACK LOSSES
= 15%
0 1000 2OOO 3000
COOLING WATER FLOW (Q), cfs
AT = CONDENSER TEMP. RISE
= PLANT THERMAL EFFICIENCY
155
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limitations based on protection of aquatic life in the
receiving water. Examples of cooling means that are or
could be employed as "helpers" are cooling towers,
unaugmented and augmented (spray) ponds and canals.
Dilution pumping also can be used to reduce discharge
temperatures. However, cooling towers, ponds and canals
have potential non-water quality environmental impacts such
as noise, fogging and drift, which are discussed in detail
in Reference 38.
The reduction in damage to aquatic organisms is in
proportion to the reduction in intake cooling water flow
volume (capacity) and closed-cycle cooling systems generally
require 2 to 4 percent of the intake cooling water flow of
once-through systems. Although all organisms withdrawn may
be killed in typical closed-cycle cooling systems, there is
strong evidence that a high proportion of fish that go
through open-cycle power plants are also killed. For
example, studies have shown that 80 percent of the fish
going through power plants with once-through cooling are
killed by abrasion, turbulence, shock and other mechanical
effects while the other 20 percent are killed by the high
temperature., as. Damage to organisms due to intake screen
effects could be significantly less for closed-cycle systems
than for once-through systems.
Combination cooling systems have been employed to operate in
open-cycle (once-through) and closed-cycle modes
interchangeably. Reference See describes the various modes
of circulating water and cooling tower operation for the
power plant as follows:
Open cycle - The open cycle operation does not utilize
the cooling tower system. Water is withdrawn from the
river, passed through the main condenser system and
returned to the river via the discharge canal.
Helper cycle - In this mode, all or a portion of the
circulating water is diverted to the cooling tower
system after passing through the main condenser. The
remainder of the water is discharged directly. All of
the water withdrawn is returned to the river with the
exception of the evaporative losses that occur in
cooling tower operation.
Recirculation cycle - In this mode, it is necessary to
withdraw from the river only a portion of the total
circulating water flow. The balance of the circulating
water flow is provided by an inventory of water
maintained and recirculated through the system. The
156
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water withdrawn, less the cooling water evaporative
losses* is returned to the river.
Closed cycle - In this mode of operation, the maximum
quantity of water is recirculated through the system.
Some withdrawals from the river are still required to
replace that lost by evaporation and that required by
blowdown. The blowdown water is returned to the river.
It is known that in at least one case the owners of a large
nuclear powerplant have agreed to backfit an offstream
(closed-cycle) cooling system on a plant originally designed
for once-through cooling in order to minimize adverse
environmental impacts caused by the high cooling water flow
volume (capacity) required by the once-through system.
157
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SECTION VI;
OPERATION AND MAINTENANCE
Introduction
The environmentally related performance characteristics of a
cooling water intake structure will be primarily established
by the location, design and capacity characteristics
discussed in the previous sections. Relatively little can
be done by the application of appropriate intake operational
measures to significantly reduce adverse environmental
impact. This results from the fact that during operation
the intake is the passive portion of the cooling water
system, which sinrply supplies the water demand of the plant.
The only portions of the intake structure that can be
"operated" are the pumps and the screens.
The development of a continuing performance monitoring
program might be of some value in determining desirable
operating conditions.
Maintenance is an aspect of intake structure operation
which can reduce adverse environmental impacts. Good
maintenance will require an effective program of preventive
maintenance for both above water and below water portions of
the intake.
Operation
Many conventional traveling screens are operated once during
each eight hour shift. During periods of high debris
loading in the water source, screens may be operated more
frequently and in some cases continuously. Pump operation
is directly controlled by the water demand from the plant.
.Little flexibility in the operation of either of these
systems is possible.
Screen Operation
The data available on screen operation suggest that, under
certain conditions, continuous operation of the screens can
reduce impingement effects. This is due to the fact that,
with continuous screen operation, fish would be impinged for
a shorter period of time. One of the primary reasons for
this is that fish typically tend to fight a situation which
they recognize as perilous such as being impinged on a
159
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screen or being lifted out of water. The longer a fish is
allowed to fight such a situation, the more likely it is to
damage itself.
Continuous screen operation to reduce impingement effects is
only effective where fish separation and bypass systems are
available. The number of installations having this
capability is small. Continuous screen operation will
shorten screen life and increase maintenance costs to some
degree.
Pump Operation
Control of pump operation has been used at certain
powerplant once-through cooling water intakes (plant no.
3608) in the northern latitudes to reduce impingement
effects during the winter months. This type of control
involves the reduction of the volume of water pumped during
these cold water periods. Pump flows can be reduced
without detrimental effect on plant performance if water
temperatures are low enough to compensate for the reduced
volume of cooling water.
Since fish swimming ability for many species is drastically
reduced at low water temperatures, a flpw reduction in the
winter period can effectively reduce fish impingement. The
best way to reduce water flow is to reduce the pump speed.
This can only be done where pumps have variable speed
drives. Unfortunately, most circulating water pumps do not
have variable speed capability. Other methods of flow
control include valve throttling, shutdown of one or more
pumps in multiple pump installations and bypassing some of
the pump discharge back into the pump well via suitable
bypass piping.
On new structures the effects of a reduced number of pumps
operating in winter should be evaluated and considered in
the overall initial design.
Recirculation
In this method each pump is operated at its normal capacity,
however, a percentage of the pump discharge is recirculated
through a pipe loop to a point in the intake bay just behind
the screen. Thus, flow through the screen to the condensers
is reduced. Recirculation can be employed only during
periods of anticipated need, however, the results of the
increased discharge temperature should be considered. 3*
Performance Monitoring
160
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The development of a continuing performance monitoring
program in conjunction with the operation of intake
structures would be helpful. The data developed on the
performance of various intake systems under different
regional conditions could be used to develop a base on
intake performance. This would allow the effectiveness of
individual intake structure characteristics to be determined
and facilitate the periodic updating of the documented
state-of-the-art.
The following type of data might be included:
- Source water temperatures
- Stream flows (where applicable)
- Screen operaton schedules
- Cooling water flow
- Number, types and condition of important
organisms impinged, entrained, and bypassed. .
Maintenance
An effective preventive maintenance program can be developed
for both below water and above water portions of the intake
structure.
The maintenance of the above water portion of the intake
will basically consist of the maintenance of the mechanical
equipment associated with the intake. This equipment
includes primarily the screens and screen drives, the trash
racks and supporting equipment.
Suggested preventive maintenance procedures are normally
supplied by the manufacturer of the various systems. This
program consists of regular lubrication schedules for all
moving parts and a firm inspection program to check key wear
points, particularly screen basket lugs, headshaft lugs,
carrying chains, etc. Inspection of the spray wash system
can be made on a regular basis with particular emphasis on
the condition of the spray nozzles. The water screen can be
tested for binding and misalignment on a monthly basis by
operating the screen for several revolutions with the test
shear pin left in place. Adequate maintenance procedures
also require the stocking of a spare parts inventory because
of- long lead times which generally exist on spare parts
deliveries. The suggested list of spare parts will
generally be supplied by the equipment manufacturer.
Preventive maintenance of the portion of the intake below
the water line is important and often neglected because it
161
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usually requires the dewatering of the individual intake
bays and/or use of divers. Below water maintenance can
include visual inspection of footwells and footwell bushings
on an annual basis. This may require a diver if the well
cannot be dewatered or the screen cannot be raised. In
addition, periodic below water inspection of the intake can
reveal the extent of the following adverse conditions as
noted in Reference 4:
- Silt accumulation in front of the structures which can effect
intake hydraulics.
- Undermining of the base of the structure which might cause
subsequent collapse of the structure.
- Deterioration of stop log and screen guides.
- Spalling concrete which may expose reinforcing bars and
weaken the structure.
- Damage to pump impeller and fittings which can lead to pump
failure.
162
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SECTION VII
COST
Introduct ion
This section contains cost data relating to cooling water
intake structures. The section is organized to first
present current costs for the construction of the several
types of conventional intake structures commonly used by
industrial establishments. This is done to establish a
baseline against which the additional costs associated with
the implementation of the environmental control measures can
be compared. Following the development of this baseline
cost data, estimates are made of the costs associated with
certain intake structure environmental control measures.
The cost data contained in this section are capital costs
associated with intake structure construction only. No
consistent data on operation and maintenance of cooling
water intakes are available. Records of these costs are not
routinely kept by either the users or the manufacturers of
intake structure equipment. The magnitude of costs
associated with operation and maintenance of cooling water
intake structures are estimated to be small compared to
capital costs.
A further gualification of the data contained in this
section is required. The scarcity of detailed datci on the
constructed cost of intake structures was a major problem
area in the development of this document. This lack of data
results from the fact that most intake .structures are con-
structed as part of a larger general contract which includes
other structures on the site, and in some cases, the
complete plant. It is difficult in these cases to separate
the portion of the costs that are directly associated with
the intake structure either from the bid package or from
field records of the cost of construction put in places I.±.
was necessary therefore to synthesize the cost da'ta
available from several sources. In doing this, the costs of
intakes constructed at different dates and in different
geographical areas of the country are combined without
normalization of the data with respect to either
inflationary factors in the construction market or well
established regional cost differences. The cost data
presented must therefore be considered to be order of
magnitude costs and should be used in this context only.
163
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Cost: of Construction of Conventional Intake Structures
The cost of conventional intake structures is influenced by
both the type of intake and the size of the intake facility.
The cost of the major piece of mechanical equipment in the
intake, the traveling water screen, contributes a relatively
small portion of the total intake structure cost.
Screen Costs
The costs of furnishing and installing intake water screens
are readily available from any of the leading screen manu-
facturers. Table VII-1 is a tabulation of the cost of 16
conventional traveling water screen installations provided
by a leading screen manufacturer during 1971. These costs
have been converted to a unit flow basis and the results
tabulated in the next to the last column of the table. The
approach velocity for each installation is recorded in the
last column. The factors that most directly affect the cost
of the screens are the approach velocity and the size of the
plant. The total range of screen cost was from $2,000/cu
m/s ($0.13/gpm) to $37,400/cu m/s ($2.36/gpm). The effect
of approach velocity was pronounced with the average unit
cost for installations where approach velocity exceeded 0.3
m/s (1 fps) being $5,200/cu m/s ($0.33/gpm) compared to a
cost of $16,600/cu m/s ($1.05/gpm) for installations where
the approach velocity was less than 0.3 m/s (1 fps). The
variation with the size of flow was even more significant.
The cost of large screening units (greater than 6.3 cu m/s
(100,000 gpm) per screen) averaged $3,200/cu m/s ($0.20/gpm)
as- compared to $17,UOO/cu m/s ($1.10/gpm) for smaller units
(less than 3.2 cu m/s (50,000 gpm) per screen).
Intake Structure Costs
Estimated cost data for the three different types of intake
structures are shown in Figure VII-1. These data were taken
from Reference 11 for small powerplants and from estimated
costs of individual large powerplants from various sources.
The base year for these cost data is 1971. The figure
demonstrates the two important cost impacting factors in
conventional intake construction. The first of these is the
type of intake used. The offshore intake will cost
significantly more, in all size ranges, than either the
shoreline intake or the channel type. The basic reason for
this is the cost of excavation and laying of offshore
conduit. The cost differences between the channel type of
intake and.the shoreline intake appear to be small except in
the lower size ranges.
164
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OFFSHORE INTAKE 975 M LONG
CHANNEL INTAKE 127,7000 M3 DREDGED
OFFSHORE INTAKE
CHANNEL INTAKE
SHORELINE INTAKE
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Figure VII-1 COST OF INTAKE SYSTEMS
166
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The other significant cost factor is the size of the plant.
The cost of construction of all three types of intakes-are
shown to be significantly higher for smaller plant sizes
than for larger powerplants. For instance, the costs of
offshore intakes are shown in Figure VII-1 to vary from as
low as $3/kw of installed electrical generating capacity for
a 1000-Mw plant to as high as $90/kw for plants under 10 Mw.
The data contained in the figure have been standardized on
the basis of significant cost factors. The length of pipe
used in the development of the curve for offshore intakes
was 975 m (3200 ft). Likewise, a constant 127,700 cu m
(167,000 cu yds) of excavation was assumed for all channel
intakes. The amount of these items and their costs can vary
significantly. Reference 24 shows the costs of three off-
shore intakes constructed between 1955 and 1958. The cost
of installation of the offshore piping for these powerplants
varied from as low as $2.16 to $4.70 per kw installed.
Caution is therefore suggested in the use of this figure.
Costs of each type of intake can vary considerably from the
curves shown.
Additional data on the cost of shoreline intakes are
contained in Table VII-2. The table contains cost data on
five cooling water intake structures and four makeup water
intake structures constructed after 1965. With the ex-
ception of three makeup water structures the cost data con-
tained in the table represent construction actually put in
place. The costs of the three makeup water intakes are
detailed, cost estimates since these plants are now still
under construction. The cost data contained in the table
are substantially the same as in Figure VII-1. The cost of
shoreline intakes ranges between $l-$4/kw for the larger
size powerplants. The cost differences between makeup water
systems and circulation water systems do not appear, from
the table, to be as great on a $/kw basis as the difference
in intake flow volume would indicate. The cost data, on a
flow basis, appear to range from $40 to $90 per gpm of flow
for makeup water intakes and from $6 to $30 per gpm of flow
for circulating water intakes. For both these types of
systems the upper cost ranges are for nuclear powerplants.
The nuclear service intakes, although pumping much smaller
volumes of water, are becoming as large as the circulating
water intakes in order to accomodate backup equipment,
provide missile protection and insure operation under
maximum probable storm water flood and drawdown levels. The
data presented in Table VII-2 can be compared to the screen
cost data on the basis of $/cu m/s ($/gpm). It can be seen
that the cost of the screens is a relatively small portion
(less1 1-2%) of the intake structure cost. The bulk of the
167
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168
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cost of intakes is associated with structural features, and
is relatively independent of equipment costs, at least for
conventional intakes.
Typical rule of thumb estimating guides for intakes are
following:
the
- Water screens cost approximately $ll/sq m ($1.00/sq ft)
based on screen surface with a range of $5.50 to
$24.22;sq m ($.50 to $2.25/sq ft).
- The cost of construction of offshore pipeline per unit
length can vary from as low as $500/m ($150/ft) for
small makeup water lines to as much as $6,600/m ($2,000/ft)
for large makeup water lines.
- The cost of shoreline intakes will average approximately
$ll,000/sq m ($l,000/sq ft) based en the cross-sectional
area of the screens.
- Shoreline intakes will also vary from between $140 to
$U24/cu m ($U to $12/cu ft) of structure enclosed beneath
the operating deck with a mean of $212/cu m ($6/cu ft).
Implementation Costs
Locations! Measures
IiOcational measures could potentially have a significant
cost impact. In particular, where locational measures
involve extensive offshore piping, the intake cost can
increase significantly. Costs of offshore piping have been
detailed above, and it is shown that the cost of this work
can increase the intake cost significantly.
The choice of intake location, while a potentially available
technology to some degree for all industrial sources for
controlling the number and types of interaction with the
intake, could be more costly in the case of relocating an
existing intake, than applying a recirculating cooling
system to minimize or eliminate cooling water flow. In
general, the incremental costs associated with choice of
intake location or application of recirculating ' cooling
systems to control the number and types of organisms
interacting with the intake would be less for a new source
than for a similar existing source.
Design Measures
169
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The design measures that will increase costs significantly
are those that involve a reduced approach velocity and
flush mounting of the screens. The changes that could be
involved are shown in Figures VII-2 and VII-3. Figure VII-2
is based on the design of a hypothetical shoreline intake
structure without the modifications required to reduce the
approach velocity and incorporate flush mounting of the
screens. The unmodified design provides an approach
velocity of 0.6 m/s (2 fps) with screens set back from the
front face of the intake. The modified design (Figure VII-
3) employs an approach velocity of 0.15 m/s (0.5 fps) with
screens set at the front of the intake and fish passageways
provided between the screens and the trash racks. The total
intake flow-per-bay is approximately 10.1 cu m/s (160,000
gpm) at maximum pump runout conditions. The intake would
draw an average of 15.8 cu m/s (250,000 gpm) using two bays
with the third bay acting as a spare. This flow is
equivalent to the circulating water flow for a fossil-fired
plant with a capacity of approximately 300 Mw.
The major changes involved include the increasing of the
volume of the intake structure below the operating floor
from approximately 1190 cu m(42,000 cu ft) as shown in
Figure VII-2 to approximately 20UO cu m (72,000 cu ft) as
shown in Figure VII-3. The cost increase involved in making
these changes are shown in Table VII-3.
The total cost increase involved in making these changes is
shown in the table to be approximately $182,000 or roughly
10% of the cost of the unmodified intake.
In addition, the larger structure requires more dredging and
the construction of a sheet pile retaining wall upstream and
downstream of the intake to provide continuity to the
"flush-face" intake, and to facilitate flow through the fish
passage between the trash rack and traveling screens. The
estimated cost for . the additional work (dredging and
retaining wall) is $90,000.
The estimated cost of modifying the traveling water screens
to incorporate fish handling and bypass systems as discussed
in the design section of this portion of the report is be-
tween $15,000 and $20,000 per bay depending on the screen
size. An equivalent amount could be required to provide the
additional screen wash systems and bypass systems required.
Capacity Measures
170
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17.5m (58')
L.
0.6mps(2/fpsl
Screens
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PLAN.
Total Flow
' ft» 60m3/S
(160,000 gpm)
ELEVATION
froximate Volume
ow tne^gperating
Loor: ,1189 m^
• (42,000 cubic feet)
DESIGN OF CONVENTIONAL INTAKE
Figure VII-2
171
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Figure VII-3 DESIGN OP MODIFIED CONVENTIONAL INTAKE
172
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Costs for reducing the capacity (flow volume) of cooling
water intake structures increase in relation to the
magnitude of the capacity reduction imposed. The available
technology for achieving significant capacity reductions for
steam electric powerplant main condenser cooling water
includes the use of closed-cycle external cooling means such
as cooling towers, ponds, etc. The capabilities,
limitations and costs of employing external cooling means at
steam electric powerplants are described in detail in
Reference 38.
Costs - Other Measures
There will be additional costs for measures related to
construction and performance monitoring. The costs of these
measures are indeterminable at this time, but are not
believed to be significant.
Nonwater Quality Impacts
Energy requirements of available control technologies would
be significant in individual cases, only in relation to the
extent that certain types of recirculating cooling water
systems were employed to minimize or eliminate the use of
cooling water. For recirculating cooling water systems, the
energy and non-water quality impacts are discussed in detail
in reference 38.
Energy requirements and nonwater quality environmental
impact of all other available technologies are not known to
be significant.
174
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SECTION VIII
SUMMARY
Introduction
This section summarizes the findings of the previous
sections on background, location, design, construction,
capacity and operation and maintenance of cooling water
intake structures. The variations of available technology,
intake conditions, site location, and plant capacity are
large and the best technology available must be decided on
a case-by-case basis. The format for this section
summarizes some of the various factors involved. The
technologies discussed herein were prepared to assist in the
evaluation, on a case-by-case basis, of the best technology
available for minimizing environmental impacts.
Adverse Environmental Impacts
Adverse environmental impacts that could occur from cooling
water intakes relate to the damage or destruction of
benthos, plankton and nektonic organisms by interaction
with the industrial cooling system. Important aspects of
the intake which relate to adverse environmental impact are
the intake volume, the number and types of organisms which
interact externally with the intake or which interact
internally with the industrial cooling system, the
configuration and operational characteristics of the intake
and plant cooling system, the thermal characteristics of the
cooling system, and the chemicals added to the cooling
system for biological control.
The above impacts are highly site-specific. Therefore,
adequate biological data would be needed in each case to
determine the specific need and control strategy related to
minimizing environmental impact.
Available Technology
The range of technologies corresponding to the control of
the* number and types of organisms which interact externally
with the intake is comprised of two factors - the choice of
the location of the intake relative to the location of the
organisms; and the full array of process modifications
including the use of recirculating cooling water systems
employing offstream means to transfer process heat directly
175
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•to the atmosphere to minimize or in some cases eliminate the
use of cooling water. The technology for controlling the
number and types of organisms which interact internally with
the cooling system is comprised of an additional factor,
i. e. , the degree to which the configuration and operation of
the intake means prevents the entry of these organisms into
the cooling system. The technology for preventing the entry
of these organisms while minimizing damage due to external
interactions with the organisms is diverse, including a
multiplicity of physical and behavior barriers and including
various fish bypass and removal systems.
Damage due to internal interactions with process cooling
systems relates to the design and operation of these systems
with respect to mechanical, thermal, and chemical
characteristics. For example, the presence of a cooling
tower in a nonrecirculating cooling system could affect th,e
amount of organism damage due to the pumping, temperature"
changes, and possible chemical additives employed with the
tower.
The extent of the known present application of these
technologies to industrial cooling water intakes is
extremely limited, and is largely confined to steam electric
powerplants. However, some technologies potentially
applicable to industrial point sources have been applied to
irrigation and other flows.
Some information is available concerning the performance and
costs of various intake devices in specific applications
both at steam electric powerplants and elsewhere. However,
the reliability of predictions of performance at one site
based on performance at another site is low in many cases.
Best Technology Available
Owing to the highly site specific characteristics of
available technology for the location, design, construction
and capacity of cooling water intake structures for
minimizing adverse environmental impact, no technology can
be presently generally identified as the best technology
available, even within broad categories of possible
application. Within this context, a prerequisite to the
identification of best technology available for any specific
site should be a biological study and associated report to
characterize the type, extent, distribution, and significant
overall environmental relation of all aquatic, organisms in
the sphere of influence of the intake, and an evaluation of
available technologies, to identify the site specific best
technology available for the location, design, construction
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and capacity of cooling water intake structures for
minimizing adverse environmental impact. All plants should
be studied initially at least to determine if further
studies are necessary. Small size does not warrant
exemption from 316 (b). Further, if costly intake structure
technology would be shown to be required, expenditures
beyond the cost of recirculating.cooling water systems would
generally not be prudent since that option would remain to
significantly reduce the intake volume of cooling water.
The term "best technology available" infers the use of the
best technology available commercially at an economically
practicable cost. Consideration of the economic
practicability of employing the best technology available
also must be done on a similarly individualized basis. When
determinations concerning cooling water intake structures
for a specific point source within a particular industrial
category are being made, the Development Document
accompanying effluent limitations and new source performance
standards for that category should be referred to for
specific factors that may be relevent i:o the consideration
of economic practicability.
A summary of the available technology to be considered on a
case-^by-case basis is given below.
Acquisition of Biological Data
Data should be provided on the biological community to be
protected. Data requirements should be justified by a
reasonable potential for minimizing adverse environmental
impact commensurate with the costs for data collection. For
new steam electric powerplants withdrawing water from
sensitive water bodies, the following data should be
provided as a minimum to develop an assessment of the
biological community in the environs of the existing or
proposed intake system, including predictive studies where
needed:
- The identification of the major aquatic and other species
in the water source. This should include estimates of
population densities for each species identified, preferably
over several generations to account for variations.that may
occur.
- The temporal and spatial distribution of the identified
species with particular emphasis on the location of spawn-
grounds, migratory passageways, nursery areas, shellfish
beds, etc.
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- Data on source water temperatures for the full year.
- Documentation of fish swimming capabilities for the species
identified, and the temperature range anticipated under
test conditions that simulate as close as possible the
conditions that exist at the intake.
- Data relating the location or proposed location of the
intake with concern for the seasonal and diurnal spatial
distribution of the identified aquatic species.
Location
Plant siting and the location of the intake structure with
respect to the environment can be the most important
consideration relevant to applying the best technology
available for cooling water intake structures. Care in the
location of the intake can significantly minimize adverse
environmental impacts. Drawing water from main channels of
large streams or from biologically deficient areas and using
multilevel intakes are among the many factors that can be
considered in locating the intake structure to minimize
adverse environmental impacts. Other factors include:
- Avoidance of important spawning areas, fish migration paths,
shellfish beds or any location where field investigations
have revealed a particular concentration of aquatic life.
- Selection of a depth of water where aquatic life is
minimal if multilevel intakes are not considered.
- Selection of a location with respect to the river or tidal
current where a strong current can assist in carrying aquatic
life past the inlet area or past the face of screens.
- Selection of a location suited to the proper technical
functioning of the particular screening system to be used.
It will be diffcult and perhaps impossible in certain cases
to offset the adverse environmental impact of improper
intake location by subsequent changes in either design or
operation of the intake structure short of significantly
reducing the intake volume and/or the development of an
effective fish recovery or diversion system.
Intake location With Respect to Plant Circulation Water
Discharge
The potentially adverse effects of the recirculation of
water from the discharge back to the intake have been
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discussed. Most powerplants will prevent this to maximize
plant thermal efficiency.
Technology - Prevention of Warm Water Recirculation
All intakes should be located with respect to the plant dis-
charges in a manner that will prevent, to as great an extent
as possible, the recirculation of warm water from the dis-
charge back to the intake.
Plan and Vertical Location of the Water Inlet
The location of the water inlet with respect to the temporal
and spatial distribution of the resident and migratory
aquatic populations is • extremely important. Intake
configuration can be selected to withdraw water from any
point in the source water body. Inlets can be located to
draw water from any elevation in the source.
Technology - Location and Elevation of Water Inlet
Water inlets should be designed to withdraw water from zones
of the source that are the least productive biologically and
contain the lowest population densities of the critical
aquatic organisms. This includes both the plan and location
of the inlet and the vertical location in the source water
body.
In addition, inlets should be located to avoid spawning
areas, nursery areas, fish migration paths, shellfish beds
or any location where field investigations have revealed a
high concentration of aquatic life.
The location of the intake should also be Selected to take
advantage of river or tidal currents which can assist in
carrying aquatic life past the inlet area or past the face
of the screens.
Intake Location With Respect to the Plant
The impact on entrained organisms is directly related to the
transit time between the intake and the condenser, and the
transit time (and elevated temperature level) between the
condenser and the outfall. Therefore, the intake should be
located close to the plant.
Technology - Location of Intake With Respect to the Plant
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For nonrecirculating cooling water systems the intake
structure (as well as the outfall structure) should be
located as close to the plant as practicable.
Design
The basic conclusion related to the design section is that
there is no generally viable alternative to the conventional
traveling water screen available at the present time. Some
new screen types have recently been developed that might
prove to have generally superior environmental
characteristics following an adequate period of testing.
Certain of these designs might be superior today at certain
sites. It is noted that this is one area in which research
and development have not kept pace with the need. Research
projects directed toward the development of more effective
screening systems could have valuable results. Furthermore,
since the configuration of the intake is largely determined
by the screening system employed, the conventional intake
structure will probably remain substantially unchanged in
the near future.
Therefore, most of the design recommendations contained
herein are based on the configuration and physical design
features of conventional intake structures as previously
defined in Section III. It is anticipated that new intake
designs will emerge that may have more positive
environmental design features than the conventional intake.
One of the express overall recommendations is the
encouragement of this positive evolutionary process in the
technology. As discussed in Section III, some of the new
technologies that will influence intake design have already
been partially explored. These include the increased use of
behavorial barriers such as the louvered intakes; the
development of new types of physical screening systems such
as the horizontal traveling screen; and the increased use of
bypass systems. The present status of these technologies
and their very limited use at existing cooling water intake
structures does not justify separate recommendations for
these types of systems at the present time. However,
certain features of the following recommendations may be
applicable to these new intake concepts, as well as to
conventional intake structures.
Approach Velocities
Typical approach velocities to the traveling water screens
at existing intakes fall within the range of about 0.2«» to
0.33 mps (0.8 to 1.1 fps).
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Technology - Design Approach Velocities
The design approach velocity to the intake water screens
should be measured in the screen channel upstream from the
screens and be based on the effective portion of the screen
face. The velocity measurement should further be based on
consideration of the low water levels anticipated. The
design approach velocity should be conservatively based on
data specific to the design organism(s) at the intake
location. These data should include,as a minimum:
- The spatial and temporal distribution of the fish by size
for each species identified.
- The annual temperature range anticipated at the intake.
- The demonstrated avoidance capability, including behavior
considerations, of these species over the full range of
temperatures experienced.
Uniform Approach Velocities and Effective Screen Areas
The maintenance of uniform velocity profiles across the
screen face is an important feature in effective screen
performance. Many factors can influence the velocity
gradient at the screen face and it is not a simple task to
eliminate non-uniform velocities. Another important
consideration is the determination of the effective area to
be used in determining the approach velocity. In many
cases, the effective area is significantly less than the
full submerged area of the screen. Regular cleaning of the
intake streams should be required to assure that uniform
approach velocities are maintained.
Technology - Uniform Approach Velocities
The discharger should document that effectively uniform
velocities will be maintained over the face of the screen at
the design conditions. The discharger should also indicate
the effective screen area used in the approach velocity
calculation. Where there is reason to question this
information, hydraulic model testing, as well as velocity
-profile measurements taken at the intake should be required
of the applicant.
Selection of Screen Mesh Size '•
The selection of screen mesh size is generally based on
providing a clear opening of no more than one-half of the
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inside diameter of the condenser tubes. The powerplant
industry has generally standardized on 0.95 cm (3/8") mesh
size. While this criteron may be adequate for keeping
foreign objects out of the cooling system, it may not be
adequate for proper protection of all aquatic species. A
rational design approach for screen mesh selection based on
the design organism(s) is contained in the design portion of
the report. The data used in this approach are not
considered extensive enough for development of a firm
recommendation on screen mesh size.
However, this approach may be used in lieu of better data.
More information on this aspect of screen design should
become available in the future as the biological data
required above are developed.
Behavorial Screening Systems
None of the available behavorial screening systems have
demonstrated consistently high efficiencies in diverting
fish away from powerplant or other industrial intake
structures. The behavorial screening systems based on
velocity change appear to be adequately demonstrated for
particular locations and species, at least on an
experimental basis. More data on the performance of large
prototype systems at industrial plants will be required
before the louver system can be recommended for a broad
class of intakes. The "velocity cap" intake can be
recommended to be considered for all offshore vertical
intakes since it would add "relatively little to the cost of
the intake, and has been shown to be generally effective in
reducing fish intake tq these systems.
The performance of the electric screening systems and the
air bubble curtain appears to be erratic, and the
mechanisms governing their application are not fully
understood at the present. These types of systems might be
experimented with in an attempt to solve localized problems
at existing intakes, since the costs involved in installing
these systems are relatively small.
No successful application of light or sound barriers has
been identified. It appears that fish become accustomed to
these stimuli, thus making these barriers the least
practical of the available behavorial systems on the basis
of current technology.
Technology - Velocity Cap Intakes
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All offshore intakes should be fitted with a velocity cap
designed to minimize the intake of the design organism(s)
that are resident at the individual intake location.
Alternative designs that provide horizontal intake
velocities may provide similar results. The design approach
velocity measured at the face of the intake opening should
conform to the design approach velocities previously
discussed.
Physical Screening Systems
It is concluded that the conventional traveling water screen
will continue to be widely used at powerplants for the near
term, although this system may have some potentially
significant adverse environmental features at some
locations.
Furthermore, the fixed screening systems currently installed
at powerplant intakes, potentially have even more damaging
environmental characteristics. These systems invariably
involve longer impingement periods between cleaning cycles
and increased damage to the fish because of greater local
velocities across the more completely clogged screen. The
crude methods employed to clean fixed screens are also
damaging to fish.
Technology - Limitation of the Use of Fixed Screens
The replacement of fixed or stationary screening systems by
other types of screening systems should be considered at
high-volume intakes. The cost impact of this would be
relatively small, since the higher initial cost of rotating
equipment will be offset by the reduced labor required for
manual cleaning of the screens over the lifetime of the
intake.
Fish Handling and Bypass Facilities
There is evidence to conclude that all new intakes should
incorporate a fish handling and/or bypass system which will
allow for safe return of fish to the water source.
Unfortunately, the case of fish handling and bypass systems
in conjunction with cooling water intakes is not a highly
developed technology at the present time. Therefore, a
blanket recommendation, requiring these systems at all new
intakes cannot be made, but this technology should be
considered.
The use of fish bypass facilities at existing intakes where
fish impingement has been documented may improve the
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performance of these intakes. These types of facilities may
also be desirable in those new intakes where it is not clear
that impingement can be avoided. One type of bypass system
can be incorporated in the conventional intake using the
traveling water screen. This system assumes impingement but
minimizes its effect in the following manner:
- Impingement time is reduced by continuous operation of the
screens
- It provides a means for a gentle separation of the fish
from the screen mesh
- It provides a passageway for safe return of fish to the
water way
One installation of this type is presently being installed
on a major powerplant intake (Plant No. 5111) and was
described in detail in the design section of this report.
The basic features of this system are shown in Figure III-
41. It is believed that this type of system might have a
positive impact on the impingement problem if the
performance of this initial installation is successful.
However, this system is not sufficiently developed at
present to provide a basis for a formal general
recommendation. The progress of this type of facility
should be closely followed in the future because the system
appears to have attractive environmental features.
Control of Fouling and Corrosion
Biological fouling of the cooling water system downstream of
the intake is usually controlled by the addition of chlorine
to the cooling water. The point of application is often the
intake structure. The application of chlorine at the intake
can adversely affect any subsequent fish bypass system that
may be installed. It is, therefore, important that if
chlorine is to be administered at the intake it should be
added immediately downstream of the point(s) in the cooling
system where it is actually needed. The addition of
chlorine may seriously affect the survival chances of all
entrained organisms, and its use should be carefully
monitored and controlled.
Corrosion protection of the screening system is not a design
factor of intakes that directly affects the environment. It
will be to the advantage of the owner to insure the
integrity of screening systems by providing adequate
materials for the type of use and water quality of the
source.
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Intake Configuration . '
Of the three conventional intake structure types discussed
in the design section of this report, the approach channel
type of intake generally has sufficient potential for
environmental impact to warrant careful evaluation prior to
its use. This type of intake is shown in Figure III-U7.
Technology - Use of Approach Channel Intakes
The use of lengthy approach channel intakes should be
avoided where at all possible, except where they are
required as an integral part of the fish bypass system.
Where they are used, the 'screening facility should be
located as close as possible to the shoreline while
maintaining a satisfactorily uniform velocity distribution.
An arrangement is shown in Figure III-H8. The velocity in
the approach channel should be limited to the design
approach velocity.
An exception to the above limitation may be desirable for
the site employing a fish guidance and bypass system. The
proper functioning of a louver system, for example, requires
a controlled flow of uniform velocity. An approach channel
may be needed in order to create the hydraulic conditions
which produce the guiding effect of louvers.
There are further considerations in the .design of a shore-
line intake. In some cases at nuclear powerplants, it may
not be practical, for safety reasons, to locate the screen
structure or intake on the shoreline. Also the placement of
the intake with respect to the shoreline shoyld be such as
to limit the protrusion of the intake into the stream,
except in the case of an ocean site. Protuding intakes
cause localized eddy currents that can affect the travel of
fish to the intake. An example of this type of design is
shown in Figure 111-49.
Technology .- Limitation of Protruding Shoreline Intakes
Intakes should be designed to limit the protrusion of the
intake sidewalls in the stream.
Another important design consideration for shoreline intakes
is the location of the screens. within the confining
sidewalls of the intake. Most conventional intakes have the
screens set back from the face of the intake between
confining sidewalls. This type of setting can create
undesirable entrapment zones between the trash racks and the
screens. The recommended setting is to mount the screens
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flush with the front face of the intake as shown in Figure
IIT-50. In this type of design, it is also desirable to
design the trash racks to allow fish passage in front of the
screens. This type of intake is most suited to locations
where there is sufficient current in the source to wash the
fish past the intake. Two examples of this type of design
incorporated in existing powerplants are shown in Figures
111-51 (Plant No. 3601) and 111-52 (Plant No« 0610).
Technology - Screen Settings for Shoreline Intakes
The screen settings for all shoreline intakes should provide
for mounting the screens flush with the upstream face of the
intake. In addition, provisions should be made for fish
passageways located between the screens and the trash racks.
Use of Walls
Walls are often used to select water from the coldest
portion of the source. The use of a wall is shown in
Figure III-4. . Walls not only create non-uniform velocity
conditions at the screens, but also create a dead area where
fish can become entrapped. Fish will not usually swim back
under the wall to safety. It is recommended that the
avoidance of this type of construction be ^considered.
Technology - Limitation on the Use of Walls
The use of walls for the purpose of selecting cold water
should be avoided. Walls may be used where required to
prevent the recirculation of warm water or to select water
from biologically safe areas of the source. Both of these
factors are contained in previous guidelines..
Pier Design
Many intakes utilize a pier which protrudes upstream of the
screens and serves as a dividing wall between adjacent
screen channels. This type of design, shown in Figure III-
53r is not consistent with the concept of flush mounting of
screens and should therefore not be used.
Pump to Screen Relationships
The relationship of the pump capacity to the screen area
provided is an important design factor at intake structures.
Several intake variations to accomodate pumps of a wide
range of sizes are shown in Figure 111-56. Care must be
taken to locate the screen with respect to the pump in a
manner which will properly utilize the entire screen
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surface. Any mismatch between screen :size and pump size can
result in undesirable velocity distribution across the
screen. Hydraulic Institute Standards recommend minimum
distances from screen to pump as well as lateral dimensions
of the screen and pump wells. However, these
recommendations are based on pump performance criteria and
not best utilization of the screen area.
Another important design consideration is the effect on
screen velocities under pump run-out conditions. This
condition exists where one pump is removed from service and
the total dynamic head on the remaining pumps is reduced.
Flow through the remaining screens may be increased by as
much as 40% above average design conditions.
It is impossible to establish a uniform recommendation that
would reflect the different problems that might arise
because of the several pump-screen relationships that exist.
However, dischargers should be required to show how their
designs have allowed for these factors.
Ice Control Facilities
Most intakes located in the northern latitudes employ a
partial recirculation of warm condenser discharge back to
the intake to control ice buildup in front of the intake.
The potential adverse environmental effects of warm water
recirculation have been well documented. Fish will be
attracted to the intake in the winter months. At the low
water temperatures their swimming capability will be greatly
reduced and the possibility of their entrapment in the
intake will be increased.
Unfortunately, there is no alternate ice control technology
currently available to replace hot water recirculation.
Submerging the intakes can create another problem as noted
in an earlier section. Air bubble systems have not been
proven on large cooling water intakes, although they may
become acceptable following a further period of development.
The development of alternate technology for the control of
ice at intake structures is one area in which further
research should be undertaken. However, until such
technology is available the use of hot water recirculation
cannot be prohibited. These systems perform an important
function at intake structures. For this reason, the
recommendation for ice control must be qualified in a manner
that does not prohibit this system but encourages the
development of alternate technology.
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Technology - Ice Control at Intakes
The use of warm water recirculation for the purposes of con-
trolling ice at intake structures should be limited to those
installations where no other means of ice control are avail-
able. Where such a system is employed, close control of the
quantity of water recirculated and timing of its use
(intermittent if possible) should be practiced. The point
of application of the hot water should be located to
minimize the potential adverse environmental impact that can
result from the application of these systems. The applicant
is encouraged to seek alternate solutions to the ice control
problem. Intermittent operation of ice control could
prevent fish accumulations which might occur with a
continuous ice control using warm water recirculation.
Aesthetic Design
Where the intake structure and the balance of the plant are
separated by great distances, the intake structure can have
an obJectionable physical presence. This will be
significant in .wilderness areas and in natural and historic
preserves. There are various techniques available to blend
•the intake structure with its surroundings. The intake may
also be lowered to reduce its impact. However, this latter
approach can increase costs significantly especially where
rock excavation is required. Where the plant and intake are
located close together, the intake will be dominated by the
plant and various architectural treatments can be applied to
create an attractive grouping of structures. This latter
factor is another reason for locating intakes close to the
balance of the plant. Since aesthetic impacts are governed
by location conditions, a general measure for aesthetic
design is not recommended.
Noise Control
The sound level of large circulating water pumps can be
quite high. The noise level emanating from an intake
located close to the plant will be dominated by the noise of
the plant. Current practice, however, is to construct
intakes, in milder climates, without enclosures. Where
intake noise level is a factor, they should be enclosed.
Enclosed intakes would not have significant sound levels.
A uniform measure is not recommended.
Construction
The adverse environmental .impact of the construction of
cooling water intake structures consists almost entirely of
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the effects of the aquatic population of the turbidity
increases created by the various construction activities.
The U.S. Army Corps of Engineers already is responsible for
construction in navigable waterways and all intake
construction will have to conform to the Corps' guidelines
for dredging, disposal of soil, etc.
Dredging, Excavation and Backfilling
These activities can cause significant short term increases
in the turbidity of the source water. Depending on the
particle size, distribution of the excavated materials and
the hydrology of the source, the impact of the turbidity
increase will be local or widespread. It is believed that a
two-fold approach for the control of turbidity increase is
required. First, a limit should be considered for the level
of turbidity increase resulting - from these operations.
Second, typical requirements, as follows, should be utilized
to reduce the impact of individual construction operations.
Technology - Turbidity Increase Resulting From Dredging
Excavation and Backfilling
The limit on the turbidity increase resulting from
contruction operations at cooling water intake structure
sites should reflect the magnitude of adverse environmental
impacts that are likely to occur. This acceptable level of
turbidity should be based, as a minimum, on existing water
quality standards for the classification of the particular
water body.
Technology - Typical Requirements for Dredging, Excavation
and Backfilling
- Excavation in low lying areas in the vicinity of the water
body should be conducted with natural soil plugs or berms
left in place. When these soil plugs are removed, the one
furthest away from the stream should be removed first.
- Where excavations are dewatered during construction, no
discharge from the dewatering pump should be made to the
waterbody unless it conforms to the turbidity limit
described above.
- Materials excavated should be placed above the water line.
Suitable slope protection for excavated materials should
be provided.
- Underwater excavations for conduit should be scheduled to
allow placing of the conduit and the closing of the
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excavation to be completed as rapidly as possible.
Backfill over conduit below the water line should be
leveled to prevent sediment transport.
- Where large excavations and dredging operations are
required it may be desirable to conduct these operations
behind a retaining structure such as an earth embankment
or a coffer dam. Care must be taken in the construction
and removal of these facilities so that the turbidity
limits established above are not exceeded.
The applicable outline specifications contained above should
be incorporated in all intake construction where required.
The discharger should indicate that these specifications
shall be incorporated into the contract documents for the
construction of the intake.
Construction Scheduling
The construction of intakes ' can often be scheduled in a
manner that can reduce adverse environmental impact. In
many waterbodies there are significant water level
variations during the year. It may be possible to schedule
much of the intake construction during low water periods
when it can be done above . water level. In addition,
construction should be scheduled to avoid spawning seasons
and migration periods where turbidity increase can harm
these functions. The ability to schedule in this fashion
requires that the appropriate biological data be made
available.
Technology - Construction Scheduling
The scheduling of intake structure construction should
consider low water periods to undertake certain construction
work above the water level. Scheduling should also consider
known periods of fish spawning and migration.
Disposal of Spoil
The disposal of spoil within navigable waters is controlled
by the U.S. Army Corps of Engineers. In addition to any
requirements that the Corps establish, it is necessary to
prevent the disposal of spoil in known fish spawning,
feeding areas, shellfish beds and over important benthic
deposits. The disposal of spoil in these areas can cause
permanent loss of important biological species. In
addition, spoil deposits both below the water and above the
water should be adequately stabilized to prevent long term
turbidity increases due to either water currents or erosion.
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Technology - Disposal of Spoil
The disposal of spoil below the water line shouldbe
avoided. In those cases where this cannot be avoided, spoil
should not be disposed of in spawning grounds, feeding areas
and over important benthic deposits. All spoil ^eP°f^s
should be adequately stabilized to prevent long term
erosion.
Slope Protection for Excavation and Fills
The same considerations governing the stabilization of spoil
deposits are also applicable to the protection of slopes of
excavation and fills tha.t are a permanent part of the
intake.
Technology - Slope Protection for Intake Excavations and
Fills
The slopes of all excavations and fills incorporated in the
intake structure shall be adequately protected against
erosion and wave action.
Capacity
Certain potentially significant . adverse environmental
impacts are related to the intake flow volume (capacity) of
Soling water intake structures. These impacts are caused
by damage to organisms while entrained in the J^g.^f
flow and other indirect effects such as damage to habitats.
The Sffect of capacity in relation to entrapment loss
should be considered in terms of the damage to significance
of the organisms and the degree of adverse environmental
impacts that result. Where the adverse impacts cannot be
modified by less costly means, consideration of alteration
of intake volume of flow (capacity) is in order.
some intake flow volume reduction can be achieved by
utilization of a non-recirculating (once-through) cooling
system SJt by reduction through the system^ However, water
Smperature would increased at all points in the
water system downstream from the intake structure.
reductions in flow volume can be achieved by utilization of
pSial or total recirculating (closed-cycle) pooling
modes. Recirculating cooling systems are available for
significantly reducing the intake flow volume for both
existing and new steam electric powerplants as well as for
o£hlr point sources. Detailed discussions of these systems
appear in Reference 38 (for powerplants) and elsewhere.
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Operation and Maintenance
Although most of the environmental impact may occur during
actual intake operation, it will not be possible to affect
intake operation significantly once it is placed in service.
Most of the control of adverse environmental impact of
intake structures would probably be obtained in the
location, design, and capacity criteria. Some degree of
control over entrainment effects might te achieved by proper
screen operational procedures. Pump operation might also be
controlled to reduce environmental impact. It would also be
desirable to develop a program for periodic performance
monitoring of intake structures.
Maintenance is an aspect of intake structure operation
which has only indirect environmental impact. The
discharger should submit in outline form his maintenance
program for the intake system.
Screen Operation
The impact of fish impingement on screens can be reduced by
continuous screen operation to reduce the period of time
that fish are impinged on the scree'ns. This type of
operation to reduce impingement effects is only applicable
where fish separation and bypass streams are available.
Since the number of installations having this capability is
small, no general recommendations on continuous screen
operation are made. However, more of these systems may be
installed in the future. Continuous screen operation in
this manner will shorten screen life and increase
maintenance costs.
Pump Operation
The ability to control pump operation can reduce impingement
effects at certain locations during the winter months. Pump
flows often can be reduced in the colder winter months with
no detrimental effect on plant performance. Since fish
swimming ability is reduced during colder temperatures, such
a flow reduction may be desirable to reduce fish
impingement.
Performance Monitoring
A program of performance monitoring of intakes is
recommended to establish data on the performance of these
systems.
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Technology - Performance Monitoring of Intake Structures
The performance of intakes should be monitored on a
continual basis. The owners of intake structures should
periodically submit performance data consisting of the
following:
- Source water temperatures
- Stream flows (if applicable)
- Screen operation schedule !
- Cooling water flow
- Number, types, and condition of important organisms
impinged, entrained, and bypassed.
Applicability of Intake Structure Technology
Consideration of the factors described in this document will
be required for existing as well as new structures. In
determining the best technology available for existing
structures, the degree of adverse environmental impact
should be considered. An existing structure may conform to
best technology available despite the fact that it does not
conform in all details to criteria recommended in this
document. New structures can be expected to incorporate the
most advanced technology available to minimize adverse
environmental impacts.
Consideration of the economic practicability of installing
available technology should be part of an intake structure
evaluation. The development document accompanying effluent
limitations and new source performance standards for a
particular industrial category should be referred to for
factors specific to point source water for that category
which may be relevant to the consideration of economic
practicability.
In many cases an existing establishment may have reason to
replace the nonrecirculating cooling water system with an
essentially closed recirculating system. The reduction in
intake water quantity by installing the closed cooling
system should significantly reduce adverse environmental
impact resulting from the cooling iwater intake structures.
Furthermore, intake flow could be reduced during certain
time periods to minimize adverse environmental impact.
A stepwise thought process is recommended for cases where
adverse environmental impact must be minimized by
application of best technology available:
193
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The first step should be to consider whether the adverse
impact will be minimized by the modification of the existing
screening systems. The possible modifications that can be
applied are discussed in the design section of this report.
The performance of this type of modification has not been
fully documented because initial installation is presently
under construction. However, the cost of in-place
modifications of this type are not excessive and they can
generally be made while the plant is operating.
The second step should be to consider whether the adverse
impact will be minimized by increasing the size of the
intake to reduce high approach velocities. This will
require additional screen and pump bays and most likely the
replacement of the existing pumps to reduce the flow through
each bay. This type of modification could also be done
while the structure is kept in service but only where extra
screen bays are available.
The third step should be to consider whether to abandon the
existing intake and to replace it with a new intake at a
different location and incorporting an appropriate design in
order to minimize adverse environmental impact. This could
be very costly particularly if an offshore inlet is
required. The recommendation of such a change should be
very carefully considered. However, a particular discharger
may elect to avoid the costs and uncertainties associated
with the first two steps and proceed directly to step three.
The time required for the installation of these changes at a
steam electric powerplant, for example, will vary from as
low as 3-4 months for the modification of an individual
screen bay to as much as two years to completely construct a
new intake.
Finally, if the above technologies would not minimize
adverse environmental impact, consideration should be given
to the installation of a closed cooling system with
appropriate design modifications as necessary.
194
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SECTION IX
ACKNOWLEDGMENTS
The development of this report was accomplished through the
efforts of Burns and Roer Inc., and Dr. Charles R. Nichols
of the Effluent Guidelines Division. The following Burns
and Roe, Inc., technical staff members made significant
contributions to this effort:
Henry Gitterman, Director of Engineering
John L. Rose, Chief Environmental Engineer
Arnold S. Vernick, Project Manager
William A. Foy, Senior Environmental Engineer
Richard T. Richards, Supervising Civil Engineer
The physical preparation of this document was accomplished
through the efforts of the secretarial and other non-
technical staff members at Burns and Roe, Inc., and the
Effluent Guidelines Division. Significant contributions
were made by the following individuals:
Sharon Ashe, Effluent Guidelines Division
Brenda Holmone, Effluent Guidelines Division
Chris Miller, Effluent Guidelines Division
Marilyn Moran, Burns and Roe, Inc.
Kaye Starr, Effluent Guidelines Division
Edwin L. Stenius, Burns and Roe, Inc.
The contributions of Ernst P. Hall, Deputy Director,
Effluent Guidelines Division were vital to the publication
of this report. Ms. Kit Krickenberger, Dr. Raymond Loehr,
and Dr. Chester Rhines of the Effluent Guidelines Division
also assisted in the preparation of this report.
The members of the working group/steering committee, who
coordinated the internal EPA review, in addition to Mr.
Cywin and Dr. Nichols are:
Walter J. Hunt, Chief, Effluent Guidelines Development
Branch, EGD
Dr. Clark Allen, Region VI
Alden G. Christiansen, National Environmental Research
Center, Corvallis
Swep Davis, Office of Planning and Management
Don Goodwin, Office of Air Quality Planning and Standards
William Jordan, Office of Enforcement and General Counsel
Charles Kaplan, Region IV
Steve Levy, Office of Solid Waste Management Programs
195
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Harvey Lunenfeld, Region II
George Manning, Office of Research and Development
Taylor Miller, Office of General Counsel
Ray McDevitt, Office of General Counsel
James Shaw, Region VIII
James Speyer, Office of Planning and Management
Howard Zar, Region V
Also acknowledged are the contributions of Ronald McSwiney
and Anita Dawson, both formerly with the Effluent Guidelines
Division.
Other
are:
EPA and State personnel contributing to this effort
Allan Abramson, Region IX
Ken Bigos, Region IX
Carl W. Blomgren, Region VII
Danforth G. Bodien, Region X
Richard Burkhalter, State of Washington
Gerald P. Calkins, State of Washington
Robert Chase, Region I
William Dierksheide, Region IX
William Eng, Region I
James M. Gruhlke, Office of Radiation Programs
William R. Lahs, Office of Radiation Programs
Don Myers, Region V
Dr. Guy R. Nelson, National Environmental Research
Center, Corvallis
Courtney Riordan, Office of Technical Analysis
William H. Schremp, Region III
Edward Stigall, Region VII
Dr. Bruce A. Tichener, National Environmental Research
Center, Corvallis
Srini Vasan, Region V
Additional comments were received from:
Joel Golumbek, Region II
Dr. William A. Brungs,' National Water Quality Laboratory
Thomas Willingham, Region VIII
Barbara Pastalove, Region II
Don Miller, National Marine Water Quality Laboratory
Howard McCormick, National Water Quality Laboratory
Dr. Joel Fisher, Office of Program Integration
Dale Bryson,- Region V
Dr. Roy Irwin, Office of Enforcement and General Counsel
Effluent Standards and Water Quality
Information Advisory Committee
Other Federal agencies cooperating are:
196
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Atomic Energy Commission
National Marine Fisheries Service, National Oceanographic
and Atmospheric Administration, Department of commerce
Bureau of Reclamation, Department of the Interior
Fish and Wildlife Service, Department of the Interior
Tennessee Valley Authority
Additional comments were received from:
Office of the Secretary, Department of Health,
Education and Welfare
Office of the Secretary, Department of the Interior
Department of the Treasury
Honorable Mike McCormack .
Water Resource Council
Department of Agriculture
Department of Defense
The Environmental Protection Agency also wishes to thank €he
representatives of the steam electric generating industry,
including the Edison Electric Institute, the American Public
Power Association and the following utilities and regional
systems for their cooperation and assistance in arranging
plant visits and furnishing data and information.
Alabama Power Company
Canal Electric Company
Central Hudson Gas & Electric Corporation
Commonwealth Edison Company
Consolidated Edison Company of New York, Inc.
Consumers Power company
Duke Power Company
Florida Power & Light Company
Fremont, Nebraska Department of Utilities
MAPP Coordination Center for the Mid-Continent
Area Power Systems
New England Power Company
New York Power Pool
New York State Electric & Gas Corporation
Niagara Mohawk Power Corporation
Omaha Public Power District
Pacific Gas & Electric Company
Pacific Power & Light Company
Pennsylvania Power & Light Company
Portland General Electric Company
Potomac Electric Power Company
Public Service Company of Colorado
Public Service Electric & Gas Company
Sacramento Municipal Utility District
197
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Southern California Edison Company
Taunton, Massachusetts Municipal Light Plant
Texas Electric Service Company
Virginia Electric & Power company
Acknowledgment is also made to the following manufacturers
for their willing cooperation in providing information
needed in the course of this effort.
Beloit-Passavant
F. W. Brackett & Company, Ltd.
J. Blakeborough & Sons, Ltd.
FMC Corporation, Materials Handling System Division
R. E. Reimund Company
Rexnord, Inc.
Stephens-Adamson
Additional comments were received from:
Union Carbide Corporation
Shell Oil Company
Manufacturing Chemists Association
New York State Department of Environmental Conservation
State of New York Public Service Commission
Indianapolis Power and Light Company
Northern Indiana Public Service Company
Texaco, Inc.
Salt River Project
The Great Western Sugar company
Illinois Power Company
State of Michigan Department of Natural Resources
Natural Resources Defense Council, Inc.
State of New York Department of Law
Otter Tail Power Company
Quirk, Lawler and Matusky, Engineers
Deberoise and Liberman
State of New Hampshire Fish and Game Department
State of California Water Resources Control Board
Atomic Industrial Forum, Inc.
Delaware River Basin Commission
Southern Electric Generating Company
American Electric Power Service Corporation
Southern Services, Inc.
Los Angeles Department of Water and Power
Bechtel Power Corporation
Gulf Power Company
Mississippi Power Company
Georgia Power Company
Tennessee Valley Public Power Association
Detroit Edison
198
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Southwestern Electric Power Comapny
City Public Service Hoard of San Antonio
Hudson River Fishermen's Association
Tampa Electric Company
State of Illinois Environmental Protection Agency
State of Maryland Department of Natural Resources
State of Michigan Department of Natural Resources
State of Ohio Environmental Protection Agency
State of North Carolina Department of Natural ana
Economic Resources
State of Texas Water Quality Board
199
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1.
2.
3.
SECTION X
REFERENCES
Bates, D.W., "Diversion and Collection of Juvenile Fish
with Traveling Screens", U.£L Department of the
Interior, Fishery Leaflet 633, (March, 1970).
Beall, S. E., "Uses of Waste Heat", Research sponsored
by the U.S. AEC under contract with the Union Carbide
Corporation, (November 3, 1969).
"Directory", Public Power, Vol. 31, No.
February, 1973).
1, (January -
*. "Dive Into Those Intakes", Electric Light & Power. E/G
edition, pp. 52-53, (November, 1972).
5. "Electric Power Statistics", Federal Power Commission,
(January, 1972) .
6- Electrical World. Directory of Electric Utilities,
McGraw-Hill Inc., New York, 31st Edition, (1972-1973).
7. "Environmental Effects of Producing Electric Power,
Hearings before the Joint Committee on Atomic Energy
91st Congress, Second Session", Parts 1 and 2, Vol. I &
II, (October, November, 1969 and January and February,
1970) .
8. Final Environmenta1
Licensing;
Statement. USAEC. Directorate of
a) Arkansas Nuclear One Unit 1 Arkansas Power 6 Light
Co., (February, 1973).
b) Arkansas Nuclear One Unit 2 Arkansas Power 6 Light
Co., (September, 1972).
c) Davis-Besse Nuclear Power Station Toledo Edison
Company 6 Cleveland Electric Illuminating Company,
(March, 1973)„
d) Duane Arnold Energy Center Iowa Electric Light &
Power Company central Iowa Power Cooperative Corn
Belt Power Cooperative, (March, 1973).
201
-------
e)
f)
g)
h)
i)
j)
k)
1)
m)
n)
o)
P)
q)
r)
s)
Enrico Fermi Atomic .Power Plant Unit 2 Detroit
Edison Company, (July, 1972).
Fort Calhoun Station Unit 1 Omaha Public Power
District, (August, 1972).
Indian Point Nuclear Generating Plant Unit No. 2
Consolidated Edison Co, of New York, Inc., Vol. 1,
(September, 1972).
Indian Point Nuclear Generation Plant Unit No. 2
Consolidated Edison Co. Of New York, Inc. Vol. II,
(September, 1972).
James A. Fitzpatrick Nuclear Power Plant Power
Authority of the State of New York, (March, 1973).
Joseph M. Farly Nuclear Plant Units 1 and 2 Alabama
Power Company, (June, 1972)«
Kewaunee Nuclear Power Plant Wisconsin Public
Service corporation, (December, 1972).
Maine Yankee Atomic Power Station Maine Yankee
Atomic Power Company, (July, 1972).
Oconee Nuclear Station Units 1, 2 and 3 Duke Power
Company, (March, 1972).
Palisades Nuclear Generating Plant Consumers Power
Company, (June, 1972).
Pilgrim Nuclear Power Station Boston Edison
Company, (May, 1972).
Point Beach Nuclear Plant Units 1 and 2 Wisconsin
Electric Power Co. and Wisconsin Michigan Power
Company, (May, 1972).
Quad-Cities Nuclear Power Station Units 1 and 2
Commonwealth Edison Company and the Iowa-Illinois
Gas and Electric Company, (September, 1972).
Rancho Seco Nuclear Generating Station Unit 1
Sacramento Municipal Utility District, (March,
1973).
Salem Nuclear Generating Station Units 1 and 2
Public Service Gas & Electric Company, (April,
1973).
202
-------
t)
u)
v)
w)
x)
y)
aa)
bb)
cc)
ad)
ee)
9.
surry Power Station Unit 1 Virginia Electric
power Co., (May, 1972).
Surry Power Station Unit
power Co., (June, 1972).
and
2 Virginia Electric &
1 and 2
The Edwin I. Hatch Nuclear Plant Unit
Georgia Power Company, (October, 1972) .
The Fort St. Vrain Nuclear Generating
Public Service Company of Colorado, (August,
Three Mile Island Nuclear Station Units 1 and 2
Metropolitan Edison Company, Pennsylvania Electric
Company and Jersey Central Power and Light Co.,
(December, 1972).
Turkey Point Plant Florida Power and Light Co. ,
(July, 1972).
Vermont Yankee Nuclear Power station Vermont Yankee
Nuclear Power corporation, (July, 1972) .
Virail C. Summer Nuclear Station Unit 1
south Carolina Electric 6 Gas Company,
(January, 1973) .
William B. McGuire Nuclear Station Units 1 and 2
Duke Power Company, (October, 1;?72) .
Zion Nuclear Power Station Units 1 and 2
Commonwealth Edison Company, (December, 1972) .
Brunswick Steam Electric Plant Units 1 and 2
Carolina Power and Light company, (January, 1970) .
Monticello Nuclear Generating Plant
Northern States Power company, (November,
-
Phy toplankton" .
Development Progress Report No
(April
Development Progress Report No. 678,
203
-------
12. Jenson, L.D. and Brady, D.K., "Aquatic Ecosystems and
Thermal Power Plants", Proceedings of the ASCE,
(January, 1971) .
13. Maxwell, W.A., "Fish Diversion for Electrical Generating
Station Cooling Systems - A State of the Art Report",
for Florida Power & Light Co., (March, 1973).
14. Mayo, R.D. and James -W.T., "Rational Approach to the
Design of Power Plant Intake Fish Screens using both
Physical and Behavioral Screening Methods", Technical
Reprint No. 15, Kramer, Chin & Mayo, (September, 1972).
15. "Metric Practice Guide", (A Guide to the Use of SI - the
International System of Units), American Society for
Testing and Materials, Philadelphia, Pennsylvania.
16 Peterson, D.E., Sonnichsen, J.C., Jr., et al, "Thermal
Capacity of Our Nation's Waterways", ASCE Annual' &
National Environmental Engineering Meeting, (October,
1972) .
17. "Report on Best Intake Technology Available for Lake
Michigan, Preliminary Draft", Cooling Water Intake
Technical Committee, (May, 1973).
18. Richards, R.T., "Fish Protection at Circulating Water
Intake", Burns and Roe, Inc., unpublished research
paper, (May, 11, 1967).
19. Richards, R.T., "Intake for the Makeup Water Pumping
System WPPSS Nuclear Project No. 2", Prepared for
Washington Public Power Supply System, (March, 1973).
20. Richards, R.T., "intake for the Makeup Water Pumping
System, Hanford No. 2", Burns and Roe, Inc., (January.
1973) .
21. Riesbol, H.S. and Gear, R.J.L., "Application of
Mechanical Systems to Alleviation of Intake Entrapment
Problems", Presented at the Atomic Industrial Forum,
Conference on Water Quality Considerations, Washington,
D.C., (October, 2, 1972).
22. Schreiber, D.L., et al, "Appraisal of Water Intake
Systems- on the Central Columbia River", for Washington
Public Power Supply System, (March, 1973).
204
-------
23. Skrotzki, E.G.A. and Vopat, W.A., Power Station
Engineering and Economy, McGraw Hill Book Co., N.Y. ,
(1960).
24. Sonnichsen, J.C., Jr., Eentley, B.W. , et al, "A Review
of Thermal Power Plant Intake Structure Designs and
Related Environmental Considerations", Prepared for the
U.S. Atomic Energy Commission, Division of Reactor-
Development and Technology.
25. "Statistics of Privately Owned Electric Utilities of the
U.S. 1970", Federal Power Commission, (December, 1971).
26. "Statistics of Publicly Owned Electric Utilities of • the
U.S. 1970", Federal Power Commission, (February, 1972).
27. "Steam Electric Plant, Air and Water Quality Control,
Summary Report", Federal Power Commission, (December,
1969).
28. "Steam Electric Plant Construction Cost and Annual
Production Expenses", Twenty-Second Annual Supplement,
Federal Power Commission, (1969).
29. "The Electricity Supply Industry", 22nd Inquiry, The
Organization for Economic Co-operation and Development
(1972).
30. Bibko, P., et al, "Effects of Light and Bubbles on the
Screening Behavior of the Striped Bass", Westinghouse
Environmental Systems, Paper presented at the
Entrainment and Intake Screening Workshop, The John
Hopkins.University, (February 8, 1973).
31. Skinner, J.E., California Department of Fish and Game,
"Evaluation of Large Functional Louver Screening Systems
and Fish Facilities, Research pn California Water
Diversion Projects", Paper presented at the Entrainment
and Intake Workshop, The John Hopkins University,
(February 8, 1973).
32. Schuler, V.J. and Larson, L.E,, Ichthyological
Associates and Southern California Edison Company, "Fish
Guidance and Louver Systems at Pacific Coast Intake
Systems", Paper presented at the Entrainment and Intake
Workshop, The John Hopkins University, (February 8,
1973) .
33. "Beloit-Passavant Corporation Bulletin 1100".
205
-------
34. "Engineering for Resolution of the Energy - Environment
Dilemma", Committee on Power Plant Siting* National
Academy of Engineering, Washington, D.C. , (1972).
35. Clark, John and, Brownell, Willard, "Electric Power
Plants in the Coastal Zone: Environmental Issues",
American Littoral Society Special Publication No. 7,
(October, 1973) .
36. "Comments on the Environmental Protection Agency's
Proposed Guidelines and Development Document for
Proposed Best Technology Available for Minimizing
Adverse Environmental Impact of Cooling Water Intake
Structures," Submitted on behalf of the New York Power
Pool, (May, 1974) .
37. "Comments on Development Document for Proposed Best
Technology Available for Minimizing Adverse
Environmental Impact of Cooling Water Intake
Structures," Submitted by Edison Electric Institute,
(May, 1974) .
38. "Development Document for Effluent Limitations
Guidelines and New Source Performance Standards for the
Steam Electric Power Generating Point Source Category",
"U.S. Environmental Protection Agency, (October, 1974) .'
39. Beck, A.D. and. Miller, D.C., "Analysis of Inner Plant
Passage of Estuarine Biota", Paper to be presented in
Proceedings of American Society of Civil Engineers Power
Division Special conference. Boulder, Colorado, (August
12-14, 1974).
40. Schuler V.J. and Larson, L.E. "Expermental Studies
Evaluating Aspects of Fish Behaviour as Parameters in
the Design of Generating Station Intake Systems",
Paper presented in ASCE, Los Angeles Meeting (January,
1974) .
41. U.S. Atomic Energy Commission, Atomic Safety and
Licensing Board, Docket Nos. 50-324, 50-325, (July 8,
1974) .
42. "Proceedings in the Matter of Pollution of Mount Hope
Bay and its Tributaries", U. S. Environmental Protection
Agency, (1972).
43. Carpenter, E.J., Anderson, S.J. and Peck, B.B.
"Entrainment of Marine Plankton through the Millstone
Unit 1", Woods Hole Oceanographic Institute, (1972).
206
-------
44. Koo, Ted S.Y., "The Striped Bass Fishery in the Atlantic
States", Chesapeake Science,,2f 73-93, (1970).
45. Delisle, Glenn, "Preliminary Fish and Wildlife Plan for
San Francisco Bay Estuary", San Francisco Bay
Conservation and Development Commission, (1966).
46. coutant, Charles C., "Biological Aspects of Thermal
Pollution I. Entrainment and Discharge Canal Effects",
CRC Critical Reviews in Environmental Control, 341-381,
(November, 1970) .
47. Kerr, James E., "Studies on Fish Preservation at the
Contra Costa Steam Plant of the Pacific Gas and Electric
Company", California Department of Fish and Game, Fish
Bulletin No. 92, (1953).
48= "Reviewing Environmental Impact statements-Thermal Power
Plant Cooling Systems", National Environmental Research
Center, U.S. Environmental Protection Agency. (October
1973) .
49. "Review of Development Document for Location, Design,
Construction and Capacity of Cooling Water Intake
Structures", U.S. Department of Commerce Memo,
(September 18, 1974).
Additional documents currently in preparation, or recently
made available, which may be useful in the evaluation of the
best available technology for the location, design,
construction and capacity of cooling water intake structures
for minimizing adverse environmental impact are the
following:
a0 "Entrainment: Guide to Steam Electric Power Plant
Cooling System Siting, Design and Operation for
Controlling Damage to Aquatic Organisms", American
Nuclear Society Committee 18.3.
b. "Entrapment/Impingement: Guide to Steam Electric
Power Plant Cooling System Siting, Design and
Operation for Controlling Damage to Aquatic
Organisms and Intake Structures", American Nuclear
Society Committee 18.3.
c. "Proceedings of the Second Workshop on Entrainment
and Intake Screening", Electric Power Research
Institute Report No. 15 in the Cooling Water
Discharge Project RP-49.
207
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d. "Bibliography on Swimming Speeds of Fishes", Great
Lakes Fishery Laboratory, U.S. Fish and Wildlife
Service, Ann Arbor, Michigan.
e. "316 (a) Technical Guidance - Thermal Discharges".
U.S. Environmental Protection Agency.
SO. Clay, C.H., Design of Fishwavs and other Fish
' Facilities, The Department of Fisheries of CanadaT
Ottawa, 1961. '
208
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SECTION XI
GLOSSARY
Brackish Water
Water having a dissolved solids content, between that of
fresh water and that of sea water* generally from 1,000 to
10,000 mg/1.
Brine
Water saturated with a salt.
CFM ''...'
Cubic foot (feet) per minute.
Circulating Water Pumps
Pumps which deliver cooling water to the condensers of a
powerplant.
Circulating Water System
A system which conveys cooling water from its source to the
main condensers and then to the " point of discharge.
Synonymous with cooling water system.
Closed Circulating Water System
A system which passes water through the condensers, then
through an artificial cooling devi.ce, and keeps recycling
x t • . • ••'*•',''
Cooling Canal
A canal in which warm water enters at one end, is cooled by
contact with air, and is discharged at the other end.
Cooling Tower
A heat exchange device which transfers reject heat from
circulating water to the atmosphere.
Cooling Water System , , -
See Circulating Water System. |
209
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Crib
A type of inlet.
Critical Aquatic Organisms
Aquatic organisms that are commercially or recreationally
valuable, rare or endangered, of specific scientific
interest, or necessary to the well-being of some sxgnificant
species or to the balance of the ecological system.
Curtain Wall
A vertical wall at the entrance to a screen or intake
structure extending from above, to some point below, the
water surface.
Discharge
To release or vent.
Discharge Pipe or Conduit
A section of pipe or conduit from the condenser discharge to
the point of discharge into receiving waters or cooling
device.
Entrainment
The drawing along of organisms due to the mass motion of the
cooling water.
Entrapment
The prevention of the escape of organisms due to the cooling
water currents and forces involved.
Fixed or Stationary Screen
A nonmoving fine mesh screen which must usually be lifted
out of the waterway for cleaning.
FPS
Foot (feet) per second.
Foot (feet) - Designated as 11, 21, etc.
Impingement
210
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Sharp collision of organism with a physical member of the
int.ake structure.
ID
Inside diameter
Inch (inches)
Designated as 1", 2", etc.
Infiltration Bed
A device for removing suspended solids from water consisting
of natural deposits of granular material under which a
system of pipes collect the water after passage through the
bed.
Inlet Pipe or Conduit
See Intake Pipe or Conduit.
Intake Pipe or Conduit
A section of pipe or conduit from the pump discharge to the
condenser inlet; also used for the pipe leading from the
inlet to the screens or pumps.
!
kN
Kilo Newton.
MPS
Meters per second.
that lost by
Makeup Water Pumps
Pumps which provide water to replace
evaporation, seepage, or blowdown.
Mean Fork Length
The length of a fish measured from the head to the point
where the tail begins to fork.
Mine-mouth Plant
211
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A steam electric powerplant located within a short distance
of a coal mine and to which the coal is transported from the
mine by a conveyor system, slurry pipeline or truck.
Nominal Capacity
Name plate - design rating of a plant, or specific piece of
equipment.
Once-Through Circulating Water System
A circulating water system which draws water from a natural
source, passes it through the main condensers and returns it
to a natural body of water.
Powerplant
Equipment that produces electrical energy, generally be
conversion from heat energy produced by chemical or nuclear
reaction.
Pump and Screen Structure
A structure containing pumps and facilities for removing
debris from water i
Pump Chamber - :
A compartment of the intake or pump and screen structure in
which the pumps are located.
Pump Runout
The tendency of a centrifugal pump to deliver more than its
design flow when the system resistance falls below the
design head.
Recirculation System
Facilities which are specifically designed to divert the
major portion of the cooling water discharge back to the
cooling water intake.
Recirculation
Return of cooling water discharge back to the cooling water
intake.
Saline Water
212
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Water containing salts.
Sampling Stations
Locations where several flow samples are taken for analysis.
Screen Chamber
A compartment of the intake of pump and screen structure in
which the screens are located.
Screen Structure
A structure containing screens for removing debris from
water.
Sed imentation
The process of subsidence and deposition of suspended matter
carried by a liquid.
Service Water Pumps
Pumps providing water for auxiliary plant heat exchangers
and other uses.
Station
A plant comprising one or several units for the generation
of power.
Stop Logs
A device inserted in guides at the entrance to a waterway to
permit dewatering. It can be made up of individual timber
logs, but more commonly of panels of steel, timber, or
timber and concrete.
Total Dynamic Head (TDK)
Total energy provided by a pump consisting of the difference
in elevation between the suction and discharge levels, plus
losses due to unrecovered velocity heads and friction.
Trash Rack, Trash Bars, Grizzlies
A grid, coarse screen or heavy vertical bars placed across a
water inlet to catch floating debris.
Trash Rake
213
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A mechanism used to clean the trash rack.
Traveling Screen
A device consisting of a continuous band of vertically or
nearly vertically revolving screen elements placed at right
angles to the water flow. Screen elements are cleaned
automatically at the top of the revolution.
Turbidity
Presence of suspended matter such as organic or inorganic
material, plankton or other microscopic organisms which
reduce the clarity of the water.
Unit
In steam electric generation, the basic system for power
generation consisting of a boiler and its associated turbine
and generator with the required-auxiliary equipment.
Utility (Public Utility)
A company, either investor-owned or publicly owned which
provides service to the public in general. The electric
utilities generate and distribute electric power.
Velocity Cap, Fish Cap
A horizontal plate placed over a vertical inlet pipe to
cause flow into the pipe inlet to be horizontal rather than
vertical.
Wet well (Pump Chamber)
A compartment of the pump structure in which the liquid is
collected and to which the pump suction is connected.
214
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APPENDIX A
ENTRAINMENT IMPACT ON MICBOBIOTA
The following text appears in Clark, John and, Brownell,
Willard, "Electric Power Plants in the Coastal Zone;
Environmental issues", American Lii-toral Society Special
Pubication No. 7, pages V-18 through V-24 (October, 1973).
This text is presented as being illustrative of the types of
impact entrainment can have or is thought to have on
microbiota. It is included for this purpose only and should
not be construed as Agency policy with respect to specifics
cited within the text. Some editorial remarks have been
made by EPA and these are enclosed in parentheses.
Generally, it would appear that phytoplankton (can) survive
higher temperatures than zboplanktori. The whole of the
suspended microflora of estuaries--diatoms, green algae,
etc., are usually considered en masse and the analysis of
power plant impact focuses more on overall reduction of mass
productivity (photosynthetic capability) than on the number
killed of each species. Immediate and pronounced damage to
productivity is done by heat in warm seasons and by
chlorination of the plant cooling system at all times. But,
because of fast regeneration (times of many algae species,
the populations of these species) may be restabilized to
normal production within several hours after passage through
the plant and return to the source water body. In cool
seasons (ambient temperature less than 60 to 65°F) the
photosynthetic rate may be improved somewhat by increased
temperature. *
The matter is complex and must be studied and resolved
separately for each case. For purposes of our present
argument, it must be emphasized that the natural mechanisms
of estuaries and the patterns of estuarine life are such
that potential adverse impacts from inner-plant damage of
microflora are normally higher at estuarine plant sites than
open coastal sites. For example, studies in North Carolina
showed the warm season productivity of estuarine waters to
be about three times as high per unit of water (volume or
area) as the adjacent oceans and suggest, therefore, that
inner-plant damage would be heavier in terms of total
reduction of productivity for water drawn from the ocean.
For zooplankton the picture is different. zooplankton
species have longer generation spans than phytoplankton and
individual (species) appear to suffer more harm in plant
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passage. There is considerable scientific literature on
effects of inner-plant damage (with once-through systems) to
estuarine zooplankton—both the permanently suspended
species, holoplankton, and the temporarily suspended species
that usually spend only a larval stage in suspension,
meroplankton. Some species appear to alternate on a daily
basis between suspended (night) and bottom life (day) .
In a recent review of the literature, the AEC staff found
that losses of zooplankton in power plant cooling systems
range from 15 to 100 percent, but suggested that a 30
percent loss of zooplankton "may be more representative." 3
This rate seems to apply to ocean sites as well as
estuaries—the mean kill- at the Huntingtbn Plant in
California was 28.U percent. * The rate of inner-plant kill
depends upon a great number of variables of plant design and
operation, season and water temperature, and the hardiness
and the life patterns of the species involved.
(Particularly susceptible species of zooplankton are those
with appendages which can be damaged mechanically as well as
those with low thermal tolerances.)
The most valuable shellfish species have planktonic larval
stages.(meroplankton) that are vulnerable to entrainment and
to the hazards of passage through cooling systems. For
example, (a proposed power station which is to be situated
in a marsh), would do massive damage to clam populations.
Although the plant would draw water for cooling from the
bottom of the ocean just outside the inlet, the ocean water
in this area has proved to be strongly estuarine because the
estuary flushes out 85 percent of its high tide volume on
each ebb tide. Clam larvae, which transit to the ocean and
back with each change of tide, are exposed in high
concentration to entrainment by the offshore intake because
they are nonbuoyant and tend to sink toward the bottom once
they pass through the inlet and out in the ocean. All
larvae entrained would be killed in passage through the
plant because of a high delta T (U5°F) and long transit time
(period for passage through the cooling system). If
abundance is dependent upon reproductive success, as it
appears to be, the total yearly loss to the clam population
in the proposed estuary because of inner-plant kill would be
36 to 48 percent. s Lowered by this amount, it would not be
able to support increasing recreational demand. More than
15,000 citizens are already licensed for recreational
clamming, most of which occurs ' in this area, and over-
harvesting is already in evidence.
The most important zooplankton in the estuarine and food
chain are among the most vulnerable. Examples of such
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important zooplankton are: gammarids (tiny shrimplike
amphipods that live on estuarine seabeds, but whose young
are planktonic), mysids (small shrimplike creatures with
planktonic young), and copepods (tiny crustacean plankton
that provide the basic food for estuarine fish larvae).
These sensitive organisms are the foundation of nourishment
for important estuarine species.
Copepods (holoplankton) are susceptible to damage from
passage through cooling systems and their death rates appear
to be controlled by temperature of the cooling water. A
detailed study of copepods in relation to the Northport
Plant on Long Island Sound shows: "...essentially 100
percent mortality for temperatures exceeding 34 °C
(93.2°F)." « Because of a high design delta T (li»-17°C) , the
discha-rge temperature of this plant would be 34°C when Long
Island Sound temperatures reached 10°G (66°F). * It may be
concluded, therefore, that Northport kills "essentially 100
percent" of the copepods transitting its once-through
cooling system from July to early October because Long
Island Sound temperatures are above 19°C (66°F) for this
period.
Other studies at Northport showed that cop'epod kills dropped
off to 33 percent in the fall and four percent in the
winter. 7 This confirms that copepod inner-plant mortality
is dependent on characteristics of the power plant (e.g.
delta T) and seasonal temperatures in the source water body.
Further confirmation comes from work at the Brayton Point
Plant on Mt. Hope Bay, Fhode Island, Where kills of 36 to 71
percent of two copepod species were associated with summer
effluent temperatures of 26 to 30°C (79-86°F). 8
The gammarids ( important for nourishment to young fishes in
the upper estuary) do not survive plant passage as well as
the copepods. Temperature mortality curves for estuarine
species typical of Chesapeake Bay 9 show that 100 percent of
gammarids are killed by temperature alone at about 32°C
(90°F) and that significant kills begin at about 30°C
(86°F). It is apparent that, in the combination of
mechanical, chemical, and thermal impacts, virtually 100
percent of gammarids that pass through the cooling system of
estuarine-sited power plants are killed in the warm season.
By temperature alone, significant kills would start when
estuary temperatures reach 72°F for a plant with a delta T
of 1U°F or higher. Mysids are even more sensitive to themal
shock. (Time-temperature mortality) curves show that
virtually 100 percent mortality (long-term exposure) is
reached at 27«C (81°F). By temperature alone, a near 100
percent kill would occur when estuary temperatures reach
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19°C (66°F) and the cooling system delta T is 15°F (8.3°C)
or higher. Studies of a California estuarine species (name
- Neomysis Americana) showed a similar pattern with lethal
temperatures of about 78°F (25.6°C) for long-term exposure
and about 87 and 88°F (30.6-31.1°C) for short-term, or
shock, exposure (four to six minutes). *o
In attempting to generalize about inner-plant effects on
zooplankton in order to make practical recommendations, one
confronts a bewildering variety of species, experiments, and
data collections. There is by no means a consensus of
agreement among researchers on the application of the
results presented above, nor does it appear likely that any
uniform interpretation could be reached. However, these
examples serve to show that the more sensitive of the
important planktonic estuarine species can be severely
damaged by a combination of inner-plant impacts. We
conclude that damage to zooplankton is inherent in once-
through cooling, and that damage is heaviest in the warm
season because the increased temperature is synergistic with
most other impacts and is itself a mortality factor. It
appears that the following general guidelines are applicable
to estuaries of the mid-Atlantic:
Discharge
temperature
80 °F
85°F
900
95°F
Effect on
zooplankton
Death or damage to an appreciable
proportion of the more sensitive
species.
Mortality and damage high to
more sensitive species;
significant but lower for more
resistant species.
Widespread high mortality and
damage to all but the more
resistant species.
Nearly complete kill of most
important species.
The above visualizes a "typical" plant, designed for once-
through cooling with a moderate temperature rise across the
condensers and a discharge channel of moderate length. It
includes the idea that mortality factors, other than temr
perature, operate year round but that damage is greatly
accelerated in summer due to thermal shock and the
synergizing effect of temperature to mechanical or chemical
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factors involved. These guideline temperatures would not
apply to northern or southern latitudes where different
species are of different ecological races and where even the
same species are of different ecological races. For
example, Biscayne Bay (Florida) natural temperatures reach
86 to 88°F (30 to 31°C) in summer when local zooplankton are
living at temperatures that would be damaging to many of
their mid-Atlantic counterparts. These natural temperatures
are so close to stress levels that only small increases in
temperature can;have serious'effects. For example, about 10
percent of Biscayne Bay invertebrate zooplankton died in
experiments at a temperature of 91.4°F (33°C) , only a few
degrees above the natural summer maximum. For this reason,
estuarine zooplankton in southern estuaries are more
susceptible to damage from a given delta T than those in
northern estuaries.
The major unresolved question about the impact of inner-
plant damage on plankton concerns the effect on food chain
productivity and on the overall ecological balance of
estuarine systems. It is clear that some proportion of the
plankton are killed in passage, that some species are more
resistant than others, that the kill is higher in warm
seasons, and that some recovery is probable for species with
rapid reproductive power. We conclude that, in general,
power plant induced plankton kills have significant adverse
impacts in the vicinity of power plants, and these impacts
are best minimized by proper site selection and by reducing
the cooling water requirements; specifically, by the
installation of closed-cycle cooling systems, such as
cooling towers or spray ponds. We further conclude that
plants located in vital areas have adverse effects that
extend far beyond the vicinity of the power plant.
Therefore, closed-cycle cooling systems, even though they do
reduce ,the extent of damage, do not offer sufficient
protection to estuarine' life to allow them to be built in
vital areas.
REFERENCES CITED
Morgan, R.P., III and R.G. Stress, 1969. Destruction of
a phytoplankton in the cooling water supply of a steam
electric station. Chesapeake Science, Vol. 10, Nos.
364: 165-171.
Thayer, Gordon W. 1971. Phytoplankton production and
the distribution of nutrients in a shallow unstratified
219
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estuarine system near Beaufort,
Science, Vol. 12, No. U:2UO-253.
N.C. Chesapeake
3. AEC Final Environmental Statement—Shoreham Nuclear
Power Station, U. S. Atomic Energy Commission.
a. AEC 1972. Draft Environmental Statement—San Onofre
Nuclear Generating Station, Units 152. U.S. Atomic
. Energy Commission.
5. Clark, John R. 1973. The environmental impact of the
proposed Seabrook Nuclear Power Plant. Testimony before
N.H. Bulk Power Supply Site Evaluation Committee.
February 8, 1973: 88p.
6. Suchanek, T.H., Jr. and Grossman, C. 1971. Viability of
zooplankton. in: Studies on the effects of a steam
electric generating plant on the marine environment at
North Port, New York. S.U.N.Y., Stony Brook, Marine
Sci. Res. Ctr., Tech. Report Ser. No. 9:61-74.
7. AEC Final Environmental Statement—Shoreham Nuclear
Power Station. U.S. Atomic Energy Commission.
8. Gonzalez, J.G. 1972. Seasonal variation in the
responses of estuarine populations to heated water in
the vicinity of a steam generating plant,, Ph.D. thesis,
U. of R.I.: 142p.
9. Mihursky, J.A. and U.S. Kennedy. 1967. Water
temperature criteria to protect aquatic life. Trans.
Am. Fish. Soc., Vol. 96 (suppl.): 20-32.
10. Hair, James R. 1971. Upper lethal temperature and
thermal shock tolerances of the opposum shrimp, Neomysis
awatschensis, from the Sacramento-San Joaquin Estuary.
California, Calif. Fish and Game, Vol. 57, No. 1:17-27.
220
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APPENDIX B
EVALUATION APPROACH
B.
Each proposed and existing cooling water intake should be
evaluated individually in determining the best technology
applicable for that situation. Obviously, a systematic
rational approach should be used in such evaluations.
Identified below are several of the ma^or points which are
discussed in detail in the main body of the document and
that should be incorporated into the evaluation approach.
A. Water Use - If the major portion of the intake water, as
determined over an adequate period of time such as a
year, is not used for cooling purposes, the intake
structure does not meet the definition of a cooling
water intake structure and no further evaluation is
necessary.
Source - information on the location of the intake
structure, flow rate of actual or anticipated intake
water, and flow rate and other pertinent water data
relating to the water source should be provided.
Age - Existing cooling water intake structures need not
Conform to all the technology described in the
development document if environmental damage is minimal.
New intake structures may be expected to incorporate
fully the best technology available.
Economic Conditions of the Industry - The Development
Document accompanying the effluent limitations and new
source performance standards for particular industrial
categories can provide information which may be
relevant.
Engineering, Hvdrologic and Biological Data - Such
engineering information should include details on the
location, design, construction, and capacity of the
intake and on the cooling system that is being or is to
be used. Hydrologic data should help identify the
influent plume and sphere of influence of the plant.
The magnitude of the biological data required in each
case should be related to the actual or anticipated
severity of the adverse environmental impacts. The
information should be adequate to identify and quantify
any adverse environmental impacts. It is not expected
that each case will require the same information.
E.
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The 316(a) Technical Guidance Manual which EPA will
issue in the near future may provide an indication of
the information necessary to permit an evaluation of
adverse environmental impacts associated with intake
screen impingement and inner plant damage. The general
type of engineering hydrologic, and biological
information noted at the end of this Appendix may be
found useful.
F. Magnitude of Impact - The significance of any damage to
organisms or other adverse environmental impacts should
be determined with respect to the total environment in
the "sphere of influence" of the affected point source
(exclusive of pollutant discharge effects).
G.. Alternatives - If a significant adverse environmental
impact is identified, the applicant should be required
to develop a recommended plan of action to minimize the
impact with alternatives along with estimates of the
results anticipated. It is "useful to note that the
statute and the regulations require only that adverse
environmental impacts be minimized and not necessarily
eliminated altogether. In determining which
alternatives are to be permitted, the costs of the
alternatives should be considered.
Biological, hydrological and engineering data are required
to adequately evaluate present or potential impingement,
inner-plant damage, or other adverse environmental impacts.
The type of data that may be useful includes:
Engineering
1.
2.
3.
4.
Quantities of water withdrawn (weekly averages) for the
last 12 months and quantities to be withdrawn (weekly
basis) over the life of the plant; also sources and
points of discharge.
Intake velocity through various parts
channel and screen.
of the intake
Time of passage of water through various segments of the
system from the intake to the condensers or other heat
exchangers to the point of discharge (end of pipe and
end of channel) .
Data showing any differences between ambient temperature
and water temperature at screens through recirculation
or other methods of deicing or from short circuiting.
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6.
7.
8.
5. Specifications on screen mesh sizes, cleaning devices
(physical and chemical), live orgnaism-return devices,
organism diversion systems and other operational
characteristics. :
Capability of variable depth withdrawal and expected
operation modes with seasons.
The points of chlorine addition, the amounts of chlorine
used daily, monthly, and annually, the frequency and
duration of chlorination, and the maximum total residual
chlorine at the pqint of dicharge obtained during each
chlorination schedule.
A list of any other chemicals, additives, or other
discharges that are contained in the cooling water
discharge including the name, points of addition,
amounts (including frequency and duration of application
and concentrations occurring prior to dilution), and
chemical compositions if known.
Biological
1. A map showing the location and times of occurrence, in
areas in the sphere of influence of the point source
(exclusive of pollutant discharge effects), of
reproductive and nursery areas, migratory routes, and
principal macrobenthic populations.
2. Estimates or measurements of redistribution of species
or life stages of species (including those moving
through the bypass structure) from one location to
another with description of habitat changes resulting
from relocation.
3. Qualitative and quantitative impingment data by species
and life stage for the shortest intervals for which data
are available, for each season.
H. Seasonal quantitative densities of principal entrainable
forms of species, i.e., phytoplankton, zooplankton and
important egg and larval phases measured in the cooling
water intake system. Percent of damage during and after
plant passage should be identified for each season or
important time of the year for seasonal forms, i.e.,
seasonal arrival of egg forms or seasonal migration of
juvenile forms. With proposed plants, the percent
damage may be determined using laboratory simulation
with simulated temperature rise, chemical input and
mechanical stresses to simulate anticipated .plant
223
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conditions. Absent sound data on percent damage, 100%
entrainment mortality should be assumed.
5. Determination of the seasonal standing crop of important
entrainable species in the area of influence of the
plant is that area of the water body that contains
entrainable life forms which are subject to entrainment
by the plant. The area of influence is specifically
designed to protect spawning grounds, zones of
migration, coves, lakes or river sections where
entrainment might act as a large cropping mechanism in
the ecosystem. A minimum of three years of data is
desirable to propoerly describe the yearto-year
variation of this standing crop in freshwater habitats.
A more-lengthy period may be needed for marine habitats.
6. Determination of the percent of damage due to the plant
in the zone of influence or habitation of the organism.
Tripak 11/29/74 percent damage should be estimated on a
species-by-species basis before intake, after screens,
and after discharge. A damage level of more than
average year-to-year variability over the area of
influence should be considered unreasonable and
alternate technology should be investigated. If more
than one plant is present in an area of influence, the
total cumulative cropping should not exceed the annual
average variation over a minimum of three years for
freshwater inhabitats. A more=lengthy period may be
needed for marine habitats.
7. Available information on the cruising speeds (as
individuals and as schools or herds) of representative
important species of fish (juvenile stage) at summer and
winter temperatures.
The available data should be summarized in a tabular or
graphical form that simplifies the evaluation of damage
and its significance to the aquatic ecosystem. Wherever
possible species-specific data should be provided.
The foregoing is a skeletal outline of the type of approach
required for such a study. This will be supplemented by a
more detailed 316(b) guidance manual which will be published
shortly by the Agency.
224
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APPENDIX C
TOPICAL BIBLIOGRAPHY
SUPPLIED BY THE
NATIONAL MARINE FISHERIES SERVICE
225
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ACCELERATI 0 N
FISH PASSAGE RESEARCH PROGRAM
The accelerated Fish Passage Research Program
U. S. Bureau of Commercial Fisheries - Seattle, Wash., 5 vols., Dec. 1964
(See attachment) .
AIR B: U *B B L E S
Andrew, F. J. and G. H. Green
1960. Sockeye and p.ink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada
Bibko, P., et al
1973. Effects of Light and Bubbles on the Screening Behavior of the
Striped Bass, Westinghouse Environmental Systems, paper presented
at the Entrainment and Intake Screening Workshop - John Hopkins Univ.,
Feb. 8, 1973. . :
Brett, J. R., and D. MacKinnon
1952. Experiments using lights and bubbles to deflect migrating young
spring salmon. Progress Reports of the Pacific Coast Stations,
Fish. Res. Bd., Canada, No. 92, 14-15.
Brett, J. R., and D. MacKinnon
1953. Preliminary experiments using lights and bubbles to deflect
migrating young spring salmon. J. Fish. Res. Bd.. Canada, 1953,
10, 548-559.
Mayo, R. D. and W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
U. S. Environmental Protective Agency
1973. Development document for proposed best technology available fot
minimizing adverse Environmental Impact of Cooling.Water Intake
Structures, U. S. Environmental Protective Agency, December 1973.
226
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BAR
Bureau of Fisheries Bulletin
1939. Fish Screens in Irrigation Diversions, Rotary and Parallel
Bar Screens, Bulletin No. 69710, July 1939. U.S. Dept. of Int.
Bur. of Fisheries, Wash., D.C. '.
Goodier, R. D.
1956. Reclamation pioneers in fish conservation techniques.
The Reclamation Era, 1956. 42. 21-22.
Greenland, Donald C.
1968. Design considerations for construction of bar screens - Aug. 5, 1968,
memo report to Fish Facilities Section, Col. Fish. Program Office,
BCF, Portland, Oregon.
Leitritz, Earl
1952. Stopping Them: The Development of Fish Screens in California
Rotary Bar, Electric and Perforated Plate Screens, Calif.
Fish and Game, Vol. 38 No. 1 - Jan. 1952.
Reimers, Norman
1966. A low-maintenance Fish Barrier with free-flow characteristics,
horizontal bar screen - The Progressive Fish-Culturist, Apr. 1966.
Rounsefell, Ph.D George A. and W. Harry Everkart, Ph.D
1953. Fishery Science, Chap. 12, John Wiley.and Sons, Inc., New York.
Spencer, John
1935. Report of Fish Screen Installations; F. P. 39, Letter report to
E. Riggins, Chief, Div. gf Scientific Inquiry, U.S. Bureau of
Fisheries, Wash., D.C. May28, 1935. 24 pp.
U. S. Patents
(See attached list)
Wales, J. H.
1948. California's Fish Screen, Bar and Rotary Screens,
Calif. Dept. of Fish and Game, Vol.34, No. 2, April 1948.
227
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CHAIN FENCE
U. S. Patents
(See attached list)
CHAIN. MOVING
Fields, P. E., G. L. Finger and L. A. Verhoeven
1954. The use of a chain barrier to guide young salmon. Univ. of Wash.
School of Fisheries, Tech. Kept. 1, 1-11.
Fields, P. E., G. L. Finger, R. J. Adkins, R. E. Carney, and R. A. Pyke
1955. A factorial study of the response of steelhead trout, chinook -
and silver salmon fingerlings to chain barriers in moving water.
Univ. of Wash. School of Fisheries, Tech. Rept. 13. 1-7. June 1955.
CHUTE. BY" PASS
Higgins, David T.
1956. The fish chute, a part of the downstream migrant system, City of
Tacoma, Dept. of Public Utilities, Oct. 23, 1956.
C L 0 S E DC 0 0 L IN G S Y S T E M
Mayo, R. D. and W. T. James
1972. Rational 'Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
DISC
U. S. Environmental Protective Agency
1973. Development document for'proposed best technology available
for minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protective Agency, Dec. 1973.
U. S. Patents
(See attached list)
Rex Chainbelt, inc.
1968. Rex water screening equipment, Bull. No. 316-068, Rex. Chainbelt, Inc.
228
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DRUM
American Consolidated Mfg. Co.
1957. Correspondence w/drawing on proposed production of Rotary
Fish Screen to Fish and Wildlife Service, Dept. of the Interior,
Portland, Oregon- Aug. 50
Andrew, F. J.
1951. The Head-Discharge Relationships for Wire Screen in Plane and
Cylindrical Forms. International Pacific Salmon Fisheries
Commission, New Westminister, Canada.
Andrew, F. J. and G. H. Green " .
1960. Sockeye and pink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada.
Baker, S. and U. B. Gilroy
1928. The Investigation of Methods and Means of Conserving Fish Life
by Means of Proper Fish Screens and Fish Ladders, Preliminary
Report to Henry 0'Mai ley, Commissione'r of Fisheries, Wash., D.C,
Nov. 30, 1928.
Baker, S. and U. B. Gilroy
1930. The Investigation of Methods and Means of Conserving Fish Life
by Means of Proper Fish Screens and Fish Ladders, Progress Report
to Henry 0'Mailey, Commissioner of Fisheries, Wash., D. C. Jan.22,1930,
Baker, S. and U, B. Gilroy _
1932. The Investigation and Methods and Means of Conserving Fish Life
by Means of Proper Fish Screens and Fish Ladders, Progress Report
for 1931 to Henry O'Malley, Commissioner of Fisheries, Wash., D,C.
Jan. 29, 1932.
Baker, S. and U. B. Gilroy
1933. Problems of Fishway Construction, Fish Ladders, Elevators,
Mechanical Screens, and Electrical Fields at. Dams and Intakes,
Civil Engineering, Dec. 1933, pp 671-675.
Bureau of Commercial Fisheries
1958. Fishery Development Program of the Columbia River, Bureau of
Comm. Fisheries, Dept. of Interior, Progress Report through
fiscal year 1958. p. 80.
Bureau of Fisheries Bulletin
1939. Fish Screens in Irrigation Diversions, Rotary and Parallel
Bar Screens, Bulletin No. 69710, July 1939. U. S. Dept. of Int.
Bur. of Fisheries, Wash., D.C.
229
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DRUM (Contrd)
Clay, C. H.
1961. Design of Fishways and Other Facilities, Chap. 6, Queen's Printer,
Ottawa, Canada.
Department of Fisheries, State of Washington
1958. Screening program, 68th annual report, State of Washington,
D.ept. of Fisheries, pp. 16-17.
Erickson, D. M.
1940. Observations and experiments with fish screens in the Wenatchee
River System. Unpublished report, Washington State Fisheries
Dept. , .
Goodier, R. D.
1956. Reclamation pioneers in fish conservation techniques.
The Reclamation Era, 1956. 42. 21-22.
Greenland, Donald C.
1962. Operation of Temporary Downstream Migrant Facilities, Roza Dam,
Yakima River, Washington, Draft Report, Fish Facility Section
Col. Fisheries Program Office, Bureau of Commercial Fisheries,
March 21, 1962.
Hard,er, James A, . .. , .
1958. , Hydraulic Losses in a Cylindrical Fish Screen Model, Hydraulic
Lab., Univ. of California.
Heckerpth, p.. N.
1961t . Umatilia District, miscellaneous, Oregon State Game Commission,
Fishery Division, annual report 1961, ppl 307-308.
Hewkin, J. A.
1961. John Day District, spring chinook salmon and rotary screen
bypass trapping, Oregon State Game Commission, Fishery Div.,
annual report 1961 :pp. 210, 218-219. '
Kabel, C. S.
1971. Banta-Carbona Fish Screen Construction, final report, anadromous
fish project, Calif. Dept. of Fish and Game.
Kabel, C. S.
. 1974. Glenn-Colusa Fish Screen Construction, annual performance report,
Anadromous Fish Conservation Act Program, Calif. Dept..of Fish and
Game.
230
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D RUM (Cont'd)
Leitritz, Earl
1952. Stopping Them: The Development of Fish Screens in California
Rotary, Bar, Electric and Perforated Plate Screens, Calif. Fish
and Game, Vol. 38, No. 1 - Jan. 1952.
Leitritz, Earl
1952. A new mechanical fish screen for hatchery ponds, drum screen
Calif. Fish and Game, Vol. 28, No. 3 - July 1952.
Mayo, R, D. and W. T. James
1972. Rational Approach to the Design of Power Plate Intake Fish Screens
'using both Physical and .Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1962).
McKernan, D, L.
1940. A progressive report of experiments on the downstream migrating
chinook salmon fingerlings at the Dryden Ditch Screens. Unpublished
report, Wash. State Fisheries Dept., 1940.
Oregon State Game Commission
1921. Drawing - type of mechanical fish screen developed and adopted by
the Oregon Game Commission in 1921.
Oregon State Game Commission, Fishery Div,
1957. Annual Report, Salem, May 1958. 298 pp.
Pollock, Robert D.
1969. Tehama-Colusa Canal to Serve as Spawning Channel, U. S. Fish and
Wildlife Service, The Progressive Fish-Culturist, Vol. 31, Mo. 3,
July 1969. ,
Rex, Chainbelt, Inc.
1968. Rex water screening equipment, Bull. No. 316-168, Rex Chainbelt, Inc.
Rounsefell, Ph.D. George A. and W. Harry Everkart, Ph.D.
1953. Fishery Science, Chap. 12, John Wiley and Sons, Inc., New York.
Spencer, John •
1935. Report of Fish Screen Installations; F. P. 39, letter report to
E. Riggins, Chief, Div. of Scientific Inquiry, U. S. Bur. of
Fisheries, Wash., D.C. May 28, 1935. 24 p.
State of California
1974. Fish Facility Program, State of Calif., Dept. of Fish and Game and
Dept. of Water Resources, Bay-Delta Fishery Project, Monthly
Progress Reports - April 1974, p. 4 —May 1974, pp. 3 & 4 -
June 1974, pp. 5-8 - July 1974, pp. 3-5 - August 1974, pp. 4-6 -
Sept. 1974, pp. 6-8 - Oct. 1974, p. 6.
231
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DRUM (Cont'd)
Tsipliaev, A. S.
1973. Fish protective screening devices with water diversions.
Leningrad Polytechnic Institute, Dept. of Hydraulics,
USSR 166 pp.
U. S. Environmental Protection Agency
1973. Development document for proposed best technology available for
minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protection Agency, Dec. 1973.
U. S. Fish and Wildlife Service, Bureau of Commercial Fisheries,.
1964. Columbia River Fishery Program, Circ., 192, Nov. 1964.
U. S. Patents
(See attached list)
Wales, J. H.
1948. California's Fish Screen Program, Bar and Rotary Screens,
Calif. Dept. of Fish and Game, Vol. 34, No. 2, April 1948.
232
-------
E L E . C T JR. I C
Andrew, F. J. and G. H.Green
1960f Sockeye and pink salmon production ;in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada
Andrew, F. J., P. C. Johnson and L. R. Kersey
1956. Further experiments with an electric screen for downstream
migrant salmon at Baker Dam, progress report, International
Pacific Salmon Fisheries Commission, New Westminister, B.C.
Baker, S. and U. B. Gilroy . •
1928. The Investigation of Methods and Means of Conserving F~isn Life
by Means of Proper Fish Screens and Fish Ladders, Preliminary
Report to Henry O'Malley, Commissioner of Fisheries, Wash*, D.C.
Nov. 30, 1928.
Baker, S. and U. B. Gilroy
( 1930. The Investigation of.Methods and Means of Conserving Fish Life
by Means of Proper Fish Screens and Fish Ladders, Progress Report
to Henry O'Malley, Commissioner of Fisheries, Wash., D.C. Jan.22,1930.
Baker, S. and U. B. Gilroy
1932. The Investigation and Methods and Means of Conserving Fish Life
by Means of Proper Fish Screens and Fish Ladders, Progress Report
for 1931 to Henry O'Malley, Commissioner of Fisheries, Wash., D.G.
Jan. 29, 1932.
Baker, S. and U. B. Gilroy
1933. Problems of Fishway Construction, Fish Ladders, Elevators,' Mechanical
Screens and Electrical Fields at Dams and Intakes, Civil Engineering
Dec. 1933, p. 671-675. ' '
Burrows, R. E; .
1957. Diversion of Adult Salmon by an Electrical Field, U. S. Fish and
Wildlife Serv., Spec. Sci. Report No. 246.
Fish-Passage.Research Program
1964. The Accelerated Eiahpassage Research Program * U.S. Bur. of
Commercial"Fisheries - Seattle, Wash., 5 vols. Dec. 1964
(See attachment) r •-.....
Hoard, G, L. and C. Giese '
1956. Determination of the material most .suitable for electrodes in
fish-guiding. Univ. of Wash., School of Fisheries, Tech.,
Rept. 32, 1956.
Holmes, H. B.
1948. History, development and problems of the electrical fish screen,
U. S. Fish and Wildlife Service, Special Science Report, 1948,
53, 1-62.
233
-------
E L E C T R I C (Cont'd)
Kuroki, Toshiro
1951. Studies on the electric fish-screen II. On the effects of
1952. stimuli by A. C., F.R.C., and H.RcC. (In Japanese with an
English summary) Bulletin Japanese Society of Scientific
Fisheries, 1951, 17 (5), 128-31. (Also abstracted in
Biological Abstracts, 1952, 26, (12), entry 33829.)
Leitritz, Earl
1952. Stopping Them: The Development of Fish Screens in California
Rotary, Bar, Electric and Perforated Plate Screens, Calif.
Fish and Game, Vol. 38 No. 1 - Jan. 1952.
Lethlean, N. G.
1951- An investigation into the design and performance of electric
1953. fish-screens and an.electric fish counter. Transactions of the
Royal Society of Edinburgh, 1951-53, Vol. LXII, 479-526...
Mason, J.
1956. The status of field scale electrical fish guiding experiments,
N. Pac. Div.,-Corps of Engr., progress report of Fisheries-
Engineering Research Program, Nov. 1956.
Mayo, R. D. and W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
, • using both Physical and Behavioral Screening Methods, Technical
--, - Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
McMillan, F.O,
1928. Electric fish screen, Bull. U.S. Bur. of Fisheries 44.
Smith, Ph.D, E. ,D.
1966. Electric Shark Barrier Research (South Africa's)
Geo-Marine Technology Circular for Nov. 1966, Vol.2, No. 10
• 10-14 .pp. :
Tsipliaev, A. S.
1973. Fish protective screening devices with water diversions.
Leningrad Polytechnic Institute, Dept. of Hydraulics,
USSR 166 pp.
U. S. Environmental Protective Agency
1973, Development document for proposed best technology available for
minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protective Agency, Dec. 1973.
U. S. Patents
(See attached list)
234
-------
E L E C T R I C (Cont'd)
Verhoeven, L. A. and G. L. Hoard
Electro-guiding experiments on young salmon. I. Repulsion vs.
attraction. Univ. of Wash., School of Fisheries, Tech. Rept. 37.
(unpublished).
Verhoeven, L. A. and G. L. Hoard
Electro-guiding experiments on young salmon. II. Relationship
to guiding efficiency of electrode arrangement, voltage gradient
and velocity. Univ. of Wash., School of Fisheries, Tech. Rept. 38.,
(unpublished).
Verhoeven, L. A. and G. L. Hoard
, Electro-guiding experiments on young salmon. III. Relative guiding
efficiency of a.c., fullwave rectified a.c., halfwave rectified a.c.,
interrupted fullwave rectified, a.c., and d.c. Univ. of Washington,
School of Fisheries, Tech. Rept. No. 39 (unpublished)
Volz, C. D.
1962., Ignitron-pulsed electric fence guide migrating salmon.
Electronics, Vol. 35, No. 16 p. 50-52.
F I L T E R
DeVries, J. J.
1973. Sand filters for screening at water diversions a feasibility
study, Water Science and Engr. Papers No. 1053, Dept. b£
Water Science & Engr. Univ. of Calif., Davis, Nov. 1973,
Mayo, R. D. and W. TV James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening. Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
Richards, R. T.
1973. Intake for the Makeup Water Pumping System WPPSS Nuclear Project
No. 2 prepared for Washington Public Power Supply System,
(March 1973). .
Stober, Q. J., E. 0. Salo, and P. B. Swierkowski •
1971. Model of a rapid sand filter for excluding small fishes from
thermal power plant cooling water, Fisheries Research Institute,
Univ. of Wash., Dec. 22, 1971.
235
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INC L I N E D
Andrew, F. J.
1951. The Head-Discharge Relationships for Wire Screen in Plane and
Cylindrical Forms. International Pacific Salmon Fisheries
Commission, New Westminister, Canada.
Clay, C. H.
1961. Design of Fishways and Other Facilities, Chap. 6, Queen's
'Printer, Ottawa, Canada
Corps of Engineers
1962. Green Peter Fingerling Separator Plate Model, 8 progress reports
on hydraulic model study on inclined screen, Corps of Engineers,
Bonn. Hyd. Lab.
Corps of Engineers
1962. Green Peter Project, Middle Santiam River, Oregon Inclined-plane
screen, Design Memo No. 13, Fish Facilities, March 1962.
Corps of Engineers
1962. Fall Creek Reservoir, Fall Creek, Oregon, Inclined Plate Screen,
Design Memo No. 10, Spillway, Outlet Works and Fish Facilities,
May 1962.
Eicher, George J.
1960. Fish-Bypass Experience at PGE's New Hydro Projects, General
Description of the inclined screen and vertical mechanical
screen placed at an angle to flow, March 1960, Electric Light
and Power.
Erho, M. W.
1967. Evaluation of floating traps for collecting downstream migrating
salmonids from the upper end of a reservoir, State of Washington
Department of Fisheries, Jan. 1967.
Fish-Passage Research Program
1964. The accelerated Eish Passage Research Program, U. S. Bur. of Comm.
Fisheries - Seattle, Wash.^ 5 vols. Dec. 1964. (See attachment)
Gerhardt, Paul
1904. FISCHWEGE UND FISHTEICHE, Leipzig, Germany, Verlag Von Wilheim
Engelmann.
Gunsolus, Robert T. and George J. Eicher
1962. Evaluation of the fish passage facilities at Pelton Project
on the Deschutes River in Oregon, Fish Commission of Orego^
Mayl962.
236
-------
INCLINED (Cont'd)
Hamilton, J. A. R. and F. J. Andrew
1954. An investigation of the effect of Baker' Dam on downstream migrant
salmon. International Pacific Salmon Fisheries Commission, 1954,
Bulletin VI, 1-73. ;
Hulen, Bill
1967. New trapping device, boon to fish study, inclined screen,
Oregonian, Apr. 2, 1967.
Ingram, P. and L. Korn
1969. Evaluation of fish passage facilities at Cougar Dam on the South
Fork McKenzie River in Oregon, Fish Commission of Oregon, Jan. 1969.
Kabel, C. S.
1971. El Solya Fish Screen Construction, final.report, anadromous
fish project, Calif. Dept. of Fish and Game.
Kupka, K. D.
1966. A downstream migrant diversion screen. The Department of Fisheries
of Canada, The Canadian Fish Culturist, Issue 37, Aug. 1966.
Leitritz, Earl
1952. Stopping Them: The Development of Fish Screens in California
Rotary, Bar, Electric and Perforated, Plate Screens, Calif.
Fish and Game, Vol. 38 No. 1 - Jan. 1952.
Richey, Eugene P.
1956. The Skimmer, a part of the downstream migrant system, Mayfield
Fish Facilities Hydraulic Model Study of Inclined Screen, City of
Tacoma, Dept. of Public Utilities, Sept. 14, 1956.
Smith, E. M. and L. Korn
1970. Evaluation of Fish Facilities and Passage at Fall Creek Dam on
Big Fall Creek in Oregon, Fish Commission of Oregon, Oct. 1970.
Sonnichsen, J. C., Jr. B. W. Bentley, et. al.
1973. A Review of Thermal Power Plant Intake Structure Designs and
Related Environmental Considerations prepared for the U.'S. Atomic
Energy Commission, Div. of Reactor Development and Technology,
May 1973. ;
U. S. Environmental Protective Agency :
1973. Development document for proposed best technology available for
minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protective Agency, Dec. 1973.
237
-------
ING-LINED (Cont'd)
U. S. Patents
(See attached list)
Univ. of Wash. Hydraulic Laboratory
1954. Length of flow over inclined screens, Univ. of Wash. Hyd. Lab.
experiment, unpublished memo report, 1954.
Wagner, E. and F. Ingram
1973. Evaluation of Fish Facilities and Passage at Foster and Green Peter
Dams on the South Santiam River Drainage in Oregon.
238
-------
L I G H T S
Andrew, F. J. and G. H. Green
1960. Sockeye and pink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada.
Bibko, P., et. al.
1973. Effects of Light and Bubbles on the Screening Behavior of the
Striped Bass,Westinghousej Environmental Systems, paper presented
at the Entrainment and Intake Screening Workshop - John Hopkins Univ,
Feb. 8, 1973.
Brett, J. R., and Di MacKinnon
1952. Experiments using lights and bubbles to deflect migrating young
spring salmon. Progress Reports of the Pacific Coast Stations,
Fish. Res. Bd., Canada, No. -92, 14-15.
Brett, J. R., and D. MacKinnon ;
1953. Preliminary experiments using lights and bubbles to deflect
migrating young spring salmon. J. Fish. Res. Bd., Canada, 1953,
10, 548-559.
Craddock, D. R.
1956. A review of studies in guiding downstream migrating salmon with
light, N. Pac. Div., Corps of Engr, progress report on
Fisheries Engr. Research Program, Nov. 1956.
Fields, P. .E., G. L. Finger, R. J. Adkins and R. Pyke
1954. Factors influencing the efficiency of light barriers in the
guidance of young salmonidae. Univ. of Wash. School of
Fisheries, Tech. Rept. 8. 1-25.
Fields, P. E., G.L. Finger, R. J. Adkins, R. E. Carney, and R. A. Pyke
1955. A factorial study of the response of steelhead trout, chinook
and silver salmon fingerlings to light barriers in moving water.
Univ. of Wash. School of Fisheries^ Tech. Rept. 11. 1-11. June 1955.
Fields, P. E., R. J. Adkins, R. E. Carney and G. L. Finger
1955. The reaction of young silver salmon and steelhead trout to
infrared light barriers. Univ. of Wash. School of Fisheries,
Tech. Rept. 14. 1-8. Feb. 1955.
Fields, P. E., R. J. Adkins, R. E. Carney and G. L. Finger
1955. The effect of four light conditions upon the impingement of
year plus steelhead trout, silver and chinook salmon. Univ. of
Wash. School of Fisheries, Tech. Rept. 18. 1-9. Aug, 1955.
239
-------
LIGHTS (Cont'd)
Fields, P. E., D. E. Johnson, G. L. Finger, R. J. Adkins, and R0 E. Carney
1956. A field test of the effectiveness of two intensities of shaded
and unshaded lights in guiding downstream migrant salmon.
Univ. of Wash. School of Fisheries, Tech. Kept. 21. 1-33. March. 1956.
Fields, P. E. and G. L. Finger
1956. The effectiveness of constant and intermittently flashing light
barriers in guiding silver salmon. Univ. of Wash. School of
Fisheries, Tech. Rept. 22. 1-23. March 1956..
Fields, P. E. and A. K. Murray
The response of young silver salmon to a light barrier after
three levels of light adaptation. Univ. of Wash. School of
Fisheries, Tech. Rept. 27. (Unpublished).
Fields, P. E.
1956. Guiding downstream migrant salmon and steelhead trout:
A research summary. Univ. of Wash. School of Fisheries,
August 15, 1956.
Fields, P. E.
1956. Guiding downstream migrant salmon and steelhead trout.
A research summary. N.Pac. Div. Corps of Engineers,
Progress report on Fisheries Engr. Research Program.
Nov. 1956.
Fields, P. E., A. K. Murray, D. E. Johnson, and G. L. Finger
1958. Guiding migrant salmon by light repulsion and attrac-
tion in fast and turbid water. 1958, 44 pp.
Fields, P. E., D. E. Johnson, and Sayed Z. El-Sayed
. 1959.' The 1958-59 McNary Dam light guiding studies. 1959, 25 pp.
Fields, P. E.
1964. Migrant Salmon Light-Guiding Studies at Columbia River Dams.
Final Report to the U. S. Army Corps of Engineers .Under
Contract No. DA-45-108-CIVENG-63-29. 247 pp.
Fields, P. E.
1966. Migrant salmon light-guiding studies at Columbia River Dams,
N. Pac. Div., Corps of Engr., Progress Report of Fisheries
Engr. Research Program, March 1966.
University of Washington
1960. Guiding downstream migrant salmon and steelhead trout, No.Pac.
Div., Corps of Engineers, ProgressReport on Fisheries-Engineering
Research Program, July 1960.
Fry, D. E. •
1950. Moving lights lure fish past diversion channels.
Electrical World, 1950, 133. No.15, 112.
-------
LOUVERS
Andrew, F. J. and G. H. Green
1960. Sockeye and pink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada.
Babbe, A. F.
1966. Effects of Structural Geometry on the Velocity Distribution
Patterns in the Delta Fish Protection Facilities - Hydraulic
Model Studies on Louvers - 2 volumes - Water Science .and
Engr. papers 1012, Dept. of Water Resources, State of Calif.
May 1966. .
Bates, D. W. and R. Vinsonhaler
1957. Use of louvers for guiding fish - Transaction of the'American
Fisheries Society, Vol. 86 p. 38-57.
Bates, D. W., P. Logan and E. A. Personen.
1960. Efficiency Evaluation Tracy Fish Collecting Facility,
Central Valley Project California, U. S. Bureau of
Reclamation, Reg. 2, Sacramento,^California.
Bates, E. W. and S. G. Jewett, Jr. •
1961. Louver Efficiency in Deflecting Downstream Migrant Steelhead
Transaction of the American Fisheries Society, Vol. 90., No. 3,
p. 335-337.
Clay; C. H. ,
1961. Design of Fishways and Other Facilities, Chap. 6, Queen's Printer,
Ottawa, Canada.
241
-------
LOUVERS (Cont'd)
Cornell, Rowland, Hayes and Merryfield
1962. Engineering Study - Downstream Migrant Fish Screening Facility
for Willamette Falls Area, Oregon City, Oregon, Oregon State Game
Commission, Portland, Oregon, June 1962.
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bur. of Coramer.
Fisheries - Seattle, Wash., 5 vols. Dec. 1964. (See attachment)
HolubetE, T. B.
1967. Evaluation of a Louver Guidance Facility used to Sample Salmon
and Trout Emigrants, State of Idaho, Fish and Game Dept.
Federal Aid Project F49-R-4, June 1967.
Pollock, Robert D.
1969. Tehama-Colusa Canal to Serve as Spawning Channel, U. S. Fish and
Wildlife Service, The Progressive Fish-Culturist, Vol. 31, No. 3,
July 1969.
Richards, R. T.
1973. Intake for the Makeup Water Pumping System WPPSS Nuclear Project
No. 2 prepared for Washington Public Power Supply System,
(March 1973). .
Rothfus, L. and J. S. Thompson
1964. Preliminary report - Mayfield Dam Downstream Migrant Fish
Facility Evaluation Program, State of Washington Dept. of
Fisheries, Dec. 18, 1964.
Rothfus, L. and J. S. Thompson
1966. Preliminary report - Mayfield Dam Downstream Migrant Fish
Facility Evaluation Program, State of Washington Dept. of
Fisheries, Jan. 11, 1966.
Ruggles, C. P. and P. Ryan .
1964. An Investigation of Louvers as a Method of Guiding Juvenile
Pacific Salmon, The Dept. of Fisheries of Canada, The Canadian
Fish Culturist, Issue -33, Nov. 1964.
Schuler, V. J. and L. E. Larson
1973. Ichthyological Associates and Southern California Edison Co.,
Fish Guidance and Louver Systems at Pacific Coast Intake Systems,
paper presented at the Entrainment and Intake Workshop, The
John Hopkins University (Feb. 8, 1973).
Skinner, J. E.
1973. California Dept. of Fish and Game, Evaluation of Large Functional
Louver Screening Systems and Fish Facilities, Research on Calif.
Water Diversion Projects, paper presented at the Entrainment and
Intake Workshop, The John Hopkins Univ., (Feb. 8, 1973).
242
-------
L 0 U V E R S (Cont'd)
Sonnichen, J. C., Jr., B. W. Bentley, et. al. ;
1973. A Review of Thermal Power Plant Intake Structure Designs and
Related Environmental Considerations prepared for the U. S. Atomic
Energy Commission, Div. of Reactor Development and Technology,
May 1973.
Strausser, H. S. and E. P. Richey
1960. Downstream migrant separation facilities, hydraulic model studies
of louvers, City of Tacoma, Dept. of Public Utilities, Feb. 1960.
Strausser, H. S. and Nece, R.E. ;
1961. Bypass entrance study, hydraulic model study of louver bypass,
City of Tacoma, Dept. of Public Utilities, April 1961.
Thompson, J. S. and G. J. Paulik
1967. An evaluation of louvers and bypass facilities for guiding seaward
migrant salmonids past Mayfield Dam in Western Washington, State of
Wash., Dept. of Fisheries, Sept. 1967.
Thompson, J. S. and L. Rdthfus
1969. Biological observations of salmonids passing Mayfield Dam
State of Wash. Dept. of Fisheries, March 1969.
U. S. Department of the Interior, Bufeau of Reclamation, Sacramento, Calif.
1957. Fish Protection at the Tracy Pumping Plant, Development of a
Fish Salvage Facility. Feb. 1957.
U. S. Enviromental Protective Agency
1973. Development document for proposed best technology available for
minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protective Agency, Dec. 1953.
State of California
1973. Evaluation Testing Program Report for Delta Fish Protective
Facility, State Water Facilities, California Aqueduct, North
San Joaquin Division, Dept. of Water Resources and Dept. of
Fish and Game, memorandum report, 1973.
243
-------
NET
Andrew, F. J. and G. H. Green
1960. Sockeye and pink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program, U. S. Bur. of
Commercial Fisheries - Seattle, Wash., 5 vols., Dec. 1964.
(See attachment)
Graban, J. R.
1964. Evaluation of fish.facilities, Brownlee and Oxbow Dams,
State of Idaho, Fish and Game Department, May 1964.
Haas, James B.
1965. Fishery problems associated with Brownlee, Oxbow, and Hells Canyon
Dams in the Middle Snake River. Investigational report No. 4,
Fish Commission of Oregon, Jan.' 1965.
Tinney, Roy E. and H. D. Copp
1958. Mathematical analysis and model studies of the downstream migrant
fish barriers, Brownlee Hydro. Development, Div. of Industrial
Research, State College of Washington, R. L. Albrook Hyd. Lab.
Nov. 1958.
244
-------
p E R P o R;A TED PIPE
Alam, S., Parkinson, F. E.,., Hawsser
1974. Air and Hydraulic Model Studies of the .Perforated Pipe Inlet
and Protective Dolphin, Washington Public Power Supply System,
Lasalle Hydraulic Laboratory, Ltr., Feb. 1974.
Richards, R. T. . -
1973.. Intake for the Makeup Water Pumping System WPPSS Nuclear Project
No. 2 prepared for Washington Public Power Supply System.
(March 1973). :
U. S. Environmental Protection Agency
1973. Development document for proposed best technology available
for minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protection Agency, Dec. 1973.
PERFORATED P LATE
U. S. Environmental Protection Agency
1973. Development.document for proposed best technology available for
minimizing adverse Environmental Impact of Cooling Water Intake
Structures, U. S. Environmental Protection Agency, Dec. 1973.
Wales, J. H., E. W. Murphy and John Handley
1950. Perforated Plate.Fish Screens, Calif. Dept. of Fish and Game,
Vol. 36, No. 4, Oct. 1950.
P U M ? S. 'F I .S H
Dokukin, M. M. . •» . .
1972. Examination of fish pumps after pumping juvenile fish, Bybroe
Khozyaistvo, No. 9, Moskva, Sept, 1972, p. 35-37.
. Kovalev, V. M. ,
1971. The effect of fish concentration of hydraulic resistance in a
fish air lift at low. air content, Proceeding of the All-Union
Research Institute of Marine Fisheries and Oceanography, No. 5
96-103, :
Robinson, John B.
1969. Effects of Passing Juvenile King Salmon through a pump,
Anadromous Fisheries Administrative Report No. 69-1 (March 1969)
State of Calif., Dept. of.Fish arid Game.
Robinson, John B.
1971. -Effects of Passing Juvenile Steelhead, Rainbow Trout and a
Hatchery Strain of1 Rainbow Trout through a volute pump.
Anadromous Fisheries Administrative Report No. 72-3,
State of Calif., Dept. of Fish and Game, June 1971.
245 ' ! . - - •
-------
P U M P S F I S H (Cont'd)
Soil Conservation Service
1967. An Investigation of pumping effects on salmonids, French Creek
Pumping Plant, Snohomish County, Wash., Febe-Mar. 1967,
Preliminary Draft Report 4/14/67.
Summers, F.E.
1951. Fish pumping experiment, conducted at Coleman Station Hatchery,
July 30, 1951, Bur. of Sport Fish, and Wildlife 6 pp.(unpublished).
State of California
1974. Fish Facility Program, State of Calif., Dept. of Fish and Game and
Dept. of Water Resources, Bay-Delta Fishery Proj. Monthly Progress
Repts, Apr. 1974, p.'4 - May 1974, p. 3&4 - June 1974, pp 5-8 -
July 1974, pp 3-5, Aug. 1974, pp 4-6 - Sept. 1974, pp 6-8 - Oct.1974,p.6.
SOUND
Andrew, F. J. and G. H. Green
1960. Sockeye and pink salmon production relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC. Canada
Burner, C. J. and' H. L. Moore
1953. Attempts to guide small fish with underwater sound.
Spec. Sci. Rept.: Fish., U.S. Fish and Wildlife Service,
No. 11, 38 pp.
Corthuys, H. J.
A brief summary of the Literature on Subaqueous sound prepared
for U. S. Fish and Wildlife (not published).
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bur. of
Comm. Fisheries - Seattle, Wash., 5 vols. Dec. 1964.
(See attachment) .,
Mayo, R. D. and W. T. James
1972.- Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept-. 1972).
Moore, H. L. and H. W. Newman
1956. Effects of sound waves on young salmon. U. S. Fish and Wildlife
Service, Special Science Report, 1956, 172, 1-19.
State of California
1965. Fish Screens, Delta Fish and Wildlife Protection Study, State of Calif.
Dept. of Fish and Game and Dept., Water Resources Report No. 4,
June 1965, pp 8-10.
U. S. Patents
(See attached list)
246
-------
T HE R M A L
Mayo, R. D. And W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
TRAVELING. HORIZONTAL
Bates, D. W.
1970. Diversion and Collection of Juvenile Fish with Traveling Screens,
U. S. Bureau of Commercial Fisheries, Fishery Leaflet No. 633,
March 1970.
Bates, D. W., E. W. Murphey and E. F. Prentice
1970. Design and Operation of a Cantileyered Traveling Fish Screen
(model V). In Preliminary designs of traveling screens to
collect juvenile fish, p. 6-15. U. S. Fish and Wildlife Service,
Spec. Sci. Rep. Fish. 608.
Bates, D. W., and J. G. Vanderwalker
1970. Traveling screens for collection of juvenile salmon (models I and II).
In Preliminary designs of traveling screens to collect juvenile fish,
p. 1-5. U. S. Fish and Wildlife Service, Spec. Set. Report .
Fish. 608.
Bates, D. W., E. W. Murphy, and M. G. Beam
1971. Traveling Screen for Removal of Debris from Rivers, U. S. Dept. of
Commerce, NOAA Technical Report NMFS SSRT-645.
Beck, R. W. and Associates
1966. Traveling Cantilevered Fish Screen and Suspension Structure,
Sept. 1966.
Farr, W. E. and E. F. Prentice
1973. Summary Report - Mechanical Operation of Horizontal Traveling
Screen Model VII, NOAA, NMFS, Northwest Fisheries Center,
Seattle, Wash., Sept. 1973.
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bureau of
Commercial Fisheries - Seattle, Wash., 5 vols., Dec. 1964.
(See attachment)
Mayo, R. D. and W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
247
-------
TRAVELING, H. 0 R I Z 0 N T A L (Cont'd)
Prentice, E. F. and F. J. Ossiander ;
1973. Summary Report - Biological Investigation of Horizontal Traveling
Screen Model VII, NOAA, NMFS, Northwest Fisheries Center,
Seattle, Wash., Sept..1973.
Rex
1974. Rex screening equipment, Envirex, Waukesha, WI 53186, Bull, No.
316-300, 19,74.
Richards, R. T. . •
1973. Intake for the Makeup Water Pumping System WPPSS Nuclear Project
No. 2 prepared for Washington Public Power Supply System,
(March 1973).
Sonnichsen, J.C., Jr. B. W. Bentley, ejt..al.
1973. ,, A Review of Thermal Power Plant Intake Structure Designs and
Related Environmental Considerations prepared for the U. S. Atomic
Energy Commission, Div. of Reactor Development and Technology,
May 1973.
State of California ,
1965. Fish Screens, DeltajFish and Wildlife Protection Study,
"State of California Departs of Fish and Game and Dept. of
Water Resources, Report No. 4, June 1965. p. 8-10.
U. S. Patents .,
(See attached list)
248
-------
: T RAVELING. INCLINE
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bureau of
Commercial Fisheries - Seattle, Wash., 5 vols. Dec. 1964
(See attachment)
Jewett, Stanley G., Jr.
1965. Memorandum on proposed design of an inclined plane traveling
screen to Program Dir., Col.Fish Program Office, BCF, Portland,
Oregon, April 27, 1965. "
Long, C. W., R. F. Kroma
1969. Research on a System for Bypassing Juvenile Salmon and Trout Around
Low-Head Dams. U.S. Fish and Wildlife Service, Commercial
Fisheries Review. June 1969.
Mayo, R. D. and W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods» Technical
Reprint No. 15, Kramer, Chin & Mayo, (Sept. 1972).
Mueller, A. C. and J. R. Orsborn
1969. Hydraulic Model Studies of a Fish Guidance Screen, Albrook Hyd.
lab., Wash. State Univ., Research Report No. 69/9-75.
U. S. Patents
(See attached list)
TRAVELING, VERTICAL
Andrew, F. J. and G. H. Green . . .
1960. Sockeye and pink salmon production in relation to proposed dams
In the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BC, Canada
Campbell, H. Jo .
1958. Fish escapement study, Marmot screens, Oregon State Game
Commission, Fishery Civ., Annual Report 1958, p. 276-277.
Corps of Engineers
1958. Fish passage facilities, Bonneville Dam, screens for aux.-water
supply systems, Information Bull., Bonn. Hyd. Lab., Uc S. Army
Engineer Dist., Portland, OR, Report No. 66-1 - April 1958
pp. 50-51, Fig. 4, Plates 4, 5, 6, 7, 14 & 20.
Cornell, Rowland, Hayes and Merryfield
1962.' Engineering Study - Downstream Migrant Fish Screening Facility
for Willamette Falls Area, Oregon City, Oregon, Oregon State Game
Commission, Portland, Oregon, June 1962.
Clay, C. H.. » .
1961. Design of Fishways and Other Facilities, Chap. 6, Queens Printer,
- Ottawa, Canada.
249
-------
• TRAVELING, VERTICAL (Cont'd)
Eicher, George J.
1960. Fish-Bypass Experience at PGE's New Hydro Projects, General
Description of the inclined screen and vertical mechanical
screen placed at an angle to flow, March 1960, Electric Light
and Power.
Holmes, Harlan B.
1964. Rehabilitation of Savage Rapids Fish Screens, Rogue River,
Bur.of Sports Eish and Wildlife, Region 1, Dept. of Interior,
June 1964.
Kerr, J. E.
1953. Studies of Fish Preservation at the Contra Costa Steam Plant of the
Pacific Gas and Electric Co., State of Calif., Dept.of Fish and
Game, Bull. No.. 92, 1-66.
FMC Corporation
1974. No-Well Traveling Water Screen, Link-Belt, F.M.C. Corporation
Catalog 6940.
Mayo, R. D. and W. T. James
1972. Rational Approach to fee Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods, Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
Oregon State Game Commission
1956. The Control of Downstream Migrants by means of Mechanical Screens,
(Rex Traveling Water Screen) N.Pac. Div., Corps of Engr., progress
report on Fisheries-Engineering Research Program, Nov. 1956.
Oregon State Game Commission '
1960. The Control of Downstream Migrants by Means 'of Mechanical/Screens,
North Pac. Div., Corps of Engineers, Progress Report on
Fisheries-Engineering Research Program, July 1960.
Rex
1974. Rex screening equipment, Envirex, Waukesha, WI 53186, .
Bull. No. 316-300, 1974.
Rex Chainbelt, Inc. .
1968. Rex Water Screening Equipment, Bull. No.. 316-068, Rex Chainbelt, Inc.
Richards, R. T.
1967. Fish Protection at Circulating Water Intake, Burns and Roe, Inc.,
unplublished research paper, May 11, 1967.
250
-------
TRAVELING, VERTICAL (Cont' d)
Richards, R. T.
1973. Intake for the Makeup Water Pumping System WPPSS Nuclear Project
No. 2 prepared for Washington Public Power Supply System,
(March 1973).
Riesbal, H. S. and R. J. L. Gear
1972. Application of Mechanical Systems to Alleviation of Intake
Entrapment Problems, presented at the Atomic Industrial Forum,
Conference on Water Quality Considerations, Wash., B.C. Oct. 2, 1972.
Rounsefell, Ph.D George A. and W. Harry Everkart, Ph.D
1953. Fishery Science, Chap. 12, John Wiley and Sons, Inc., New York
Schreiber, D. L., et. al.
1973. Appraisal of Water Intake Systems on the Central Columbia River
to Washington Public Power Supply System (March 1973).
Sonnichsen, J. C., Jr., B. W. Bentley, et. al.
1973. A Review of Thermal Power Plant Intake Structure Designs and
Related Environmental Considerations prepared for the U. S. Atomic
Energy Commission, Div. of Re'actor Development and Technology,
May 1973.
U. S. Environmental Protection Agency
1973. Development document for proposed best technology available for
minimizing adverse Enviromental impact of Cooling Water Intake
Structures, U. S. Environmental protection Agency, Dec. 3.973.
VonGunten, G. H., H. A. Smith, Jr., and B. M. Maclean
1956. Fish Passage Facilities at McNary Dam, Auxiliary Water Supply
System, A.S.C.E. Power Division Journal, Paper No. 895,
• Feb. 1956, pp 17-18.
TT
Wagner, Harry H. .
1959. The size and location of escape ports for bypassing salmonid fish
at a screened diversion canal. Master's thesis, Corvallis, Oregon
State College, 1959. 76 numb, leaves.
251
-------
VELOCITY
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bureau of
Commercial Fisheries - Seattle, Wash., 5 vols., Dec. 1964
(See attachment)
V'ELOCITY CAP
Sonnichsen, J. C., Jr., B. W. Bentley, et. al.
1973. A Review of Thermal Power Plant Intake Structure-Designs and
Related Environmental.Considerations prepared for the U. S. Atomic
Energy Commission, Div. of. Reactor Development and Technology,
May 1973.
Spencer, R. W. and John Bruce . '
1960. Cooling Water for. Steam Electric Stations on Tidewater,
A.S.C.E. Journal of Power Division, No. 2503, June 1960.
U. S. Enviromental Protection Agency
1973. Development document for proposed best technology available for
minimizing adverse Environmental Protection Agency, Dec. 1973.
Weight, Robert H. "'''",
1958. Ocean Cooling Water System for 800-MW Power Station^ A.S.C.E.
Power Division Proceeding Paper Np. 1888, Dec. 1958.
WELL POINT
Johnson Screens '..""'
1969. John Screens, catalog 169, Universal Oil Products Company,
Johnson Div., St. Paul, Minn.
Johnson Screens
1972. Johnson Screens Modernize Water-Intake Design - Universal Oil
Products Co., Johnson Div., St. Paul, Minn. Bull. No. 10/1, March 1972.
252
-------
W I R E SCREEN
Fingado, R. P.
1971. The Sacramento River Debris Study, State of Calif., Dept. of
Water Resources, Central District, Memorandum Report
Tsipliaev, A. S.
1973. Fish protective screening devices with water diversions
Leningrad Polytechnic Institute, Dept. of Hydraulics,-
USSR 166 pp.
U. S. Patents
(See attached list) •
Schreiber, D. L., et. al.
1973. Appraisal of Water Intake Systems on the Central Columbia River
to Washington Public Power Supply System (March 1973).
B I 0 L 0 G I GAL
(Swimming Ability, Size, Behavior, Etc.)
Adkins, R. J. and P. E. Fields
1957. The conditioning of yearling steelhead (Salmo gairdneri)
to colored lights. Univ. of Wash., School of Fisheries,
Tech. Report 33.
Andrew, F. J. and G. H. Green
1960. Sockeye and pink salmon production in relation to proposed dams
in the Fraser River System, International Pacific Salmon
Fisheries Commission, Bull. XI, New Westminister, BQ> Canada
Aserinsky, E., G. L. Hoard, R. E. Nakatani and L. A. Verhoeveh
1954. Factors in pulsated direct current which cause electrotaxis
; and side effects in young salmon. Univ. of Wash., School of
Fisheries, Tech. Rept. No. 5.
Baranyak, G. F. and Tichomerov |
1969. Observations on Water Intake and Discharge Installations of
Ali-Bairamlinsky Thermal Station in Relation to the Problem
of Fish Protection - US.SR
Bell, M. C.
1973* Fisheries Handbook of Engineering Requirements and Biological
. Criteria, U. S. Army Engr. Division, North Pacific Corps of Engr.
Portland, Oregon - Feb. 1973.
Brett, J.R., D. MacKinnon, and D. F. Alderdice »
1954. Trough experiments on guiding sockeye salmon fingerlings.
Progress Reports of the Pacific; Coast Stations, Fish. Res. Bd.
Canada, 1954, No. 99, 24-27.
253
-------
BIOLOGICAL (Cont'd)
(Swimming Ability, Size, Behavior, Etc.)
Bull, H. 0. .
1928. Studies on conditioned responses in fishes. Part I.
J. Mar. Biol. Assoc. U. K., 15(2): 485-533.
Bull, H. 0.
1930. Studies on conditioned responses in fishes. Part II."
J. Mar. Biol. Assoc. U.K., JL6(2): 615-637
Burner, C. J.
1949. Vertical distribution of downstream migrating chinobk salmon
fingerlings in the Bonneville forebay, with a note upon the
rate of migration. Unpublished data U. S. Fish and Wildlife
Service memorandum of Dec. 16, 1949 to J. T. Barnaby from
C. J. Burner.
Carney, R. E. and R. J. Adkins
1955. Reactions of young silver salmon in ten velocity combinations.
Univ. of Wash. School of Fisheries, Tech. Rept. 23, 1-15, Aug.,1955.
Clancy, Dan W. .
1958. -Report on swimming ability of chules,- squawfish and suckers
in a rotating circular tank, Washington Water Power Co., July 1958
(unpublished)
Clay, C. H.
1961. Design of FishWays and Other Facilities, Chap. 6, Queen's Printer,
Ottawa, Canada
Collins, G. B. and C. H. Elling
1966. The Accelerated Fish Passage Research Program of the U. S. B.C.F. -
Summary of Progress through 1964, No. Pac. Div., Corps of Engr.
third progress report on Fisheries Engineering Research Program
March 1966'.
Delacy, A. C., S. P. Felton, and G. J. Paulik . .
1956. A study to investigate the effects of fatigue and current
velocities on adult salmon and steelhead trout. Progress Rpt.
on Fisheries Engineering Research Program, N. Pac. Div.,
Corps of Engineers, U. S. Army, Nov. 1956 pp. 126-138.
Denil, G.
1936. The mechanics of the river Fish Annalex dea Travaux Publics
Belgique, Vol. 37 Nos. 4 &• 5, Vol. 38 Nos. 1, 2, 3, 4,5 and 6;
Vol. 39, Nos. 1, 2, 3 and 4. » - •
254
-------
B I PL O G I C A L (Cont'd)
(Swimming Ability, Size, Behavior, Etc.)
Fields, P. E. and G. L. Finger
1954. The reaction of young salmonidae to light. Univ. of Wash.
School of Fisheries, Tech. Rept. 2. 1^20.
Fields, Paul E., G. L. Finger, and L. A. Verhoeven
1954. Effect of electric shock upon the light avoiding behavior of
young silver and blueback salmon. University of Washington,
School of Fisheries, Tech. Rept. No. 2, 1954. .
Fields, P. E., G. L. Finger, and L. A. Verhoeven
1954. The effect of electric shock upon the light avoiding behavior of
young silver and blueback salmon. Univ. of Washington School of
Fisheries, Tech. Rept. 3, 1-19, 1954.
Fields, P. E. and G. L. Finger
1954. The reaction of five species of young Pacific salmon and steelhead
trout to light. Univ. of Wash. School of Fisheries, Tech. Rept. .7
1-24.
Fields, P. E., R. J. Adkins, and G. L. Finger' ,
1954. The swimming ability of immature silver salmon (Oncorhynchus
kisutch) measured in an experimental flume. Univ. of Washington
School of Fisheries^ Tech. Rept. 9. 1-22.
Fields, P. E.
1954. The effect of electric lights upon the upstream passage of
spawning sockeye salmott (Oncorhynchus nerka) through the
Univ. of Wash, fish ladders. Univ. of Wash. School of:
Fisheries, Tech. Rept. 10 1-11 ';
Fields, P. E., D. E. Johnson, G. L. Finger, R. J. Adkins and R. E, Carney
1955. The effect.of various electrical treatments upon equilibrium,
swimming ability and light avoidance of silver salmon, Univ. of
Wash. School of Fisheries, Tech. Rept. 20. 1-46. Dec. 1955.
Fields, P. E.
1964. Vertical Distribution of Downstream Migrant Salmonids at the
McNary Dam, Oregon, Intake Structure. Univ. of Wash.9. Coll. of
Fisheries, Tech. Rept. 53. p. 11-42.
Fields, P. E.
1964. Diverting Downstream Migrants from the McNary Dam Turbines into
the Trash Sluiceway and Emergency Gate Slots. Univ. of Wash.,
Coll. of Fisheries, Tech. Rept. 55. p. 81-110.
Fields, P. E.
1964. Effect of Powerhouse Lights on Salmonid Tow Net Catches at McNary
Dam. UniVi of Wash., Coll. of Fisheries, Tech. Rept. 56. p. 111-136.
255
-------
BIOLOGICAL (Cont' d)
Fields, P. E. .
Nature of the Downstream Migrant's Response to Light Patterns at
The Dalles Dam. Univ. of Wash., Coll. of Fisheries, Tech. Rept. .57.
p. 137-153.
Fish-Passage Research Program
1964. The Accelerated Fish Passage Research Program - U. S. Bureau of Commercial
Fisheries - Seattle, Wash., 5 vols., Dec. 1964. (See attachment)
Greenland, Donald C.
1969. Fish Eggs and Spawning Habits Pertinent to the design of fish
screening facilities, information tabulated for Fish Facilities
Section, BCF, Col..Fisheries Program Office, Portland, Oregon
Greenland, D. C. and A. E. Thomas
1969. Swimming speed of fall chinook salmon fry, Bur. of Commercial
Fisheries, Col. Fish Program Office, Portland, Oregon (unpublished)
Hoar, W,.' S,
1951. The behavior of chum, pink and coho salmon in relation to their
seaward migration. J. Fish. Res. Bd. Canada, 1951, 8, 241-263.
Hoar, W. S. . '
1954.' The behavior of juvenile Pacific Salmon with particular reference
to the sockeye (Oncorhynchus nerka). J. Fish Res. Bd. Canada, 1954,
11, 69-97.
Hoard, G. L.
1956. Effects of electrode geometry and water conductivity on the shock
received by fish in an electrical field. Univ. of Washington,
School of Fisheries, Tech. Rept.. 24. (unpublished).
Jensen, L. D. and D. K. Brady
1971. Aquatic Erosystems and Thermal Power Plants. Proceedings of the
ASCE, Power Div., Jan. 1971.
Johnson, D. E., P. E. Fields., P. S. Karekar and G.' L. Finger
1958. Conditions Under which light attracts and repels premigratory
salmon in clear and turbid, still and running water. 1958, 15 pp.
Johnson, D. E., R. E. Nakatani and.S. P. Felton
1956. The effects of electroshock (A.C.) upon tissue content of inorganic
phosphate and lactic acid in yearling silver salmon. .1956, 6 pp.
256
-------
B I 0 L 0 G.I C A L (Cont'd)
(Swimming Ability, Size, Behavior^ Etc.)
Johnson, D. E. and P. E. Fields
1959. The orientation of sexually mature male salmon to simulated
star patterns, 1959, 9 pp.
Johnson, D. E., R. E. Nakatani, and S. P. Felton
The effects of electroshock (A.C.) upon tissue content of inorganic
phosphate and lactic acid. Univ. of Wash. School of Fisheries,
Tech. Rept. 26. (Unpublished)
Johnson, D. E. and P. E. Fields
The application of conditioning techniques to the problem, of
guiding downstream migrant salmon. Univ. of Wash. School of Fisheries,
Tech. Rept. 35. (Unpublished) : .
MacPhee, C. and F. J. Watts
1973. Swimming Performance and Migratory Behavior of Arctic Grayling,
Alaska, Progress Report to Bur. of Sport Fisheries and Wildlife,
Dec. 21, 1973.
Mayo, R. D. and W. T. James
1972. Rational Approach to the Design of Power Plant Intake Fish Screens
using both Physical and Behavioral Screening Methods. Technical
Reprint No. 15, Kramer, Chin & Mayo (Sept. 1972).
Moyer, Stanley and E. C. Raney
1969. Thermal Discharges from Nuclear Plant, A.S.C.E., journal of Sanitary
Engr. Division, No. 6983, Dec. 1969.
Murray, A. K and P. E. Fields .
1957. Response of ;steelhead trout (Salmo gairdneri) to continuous
fixed interval and fixed ratio reinforcement schedules. 1957, 10 pp..
Nakatani, R. E.
1954. The average specific electrical resistance of some salmonids.
Univ. of Wash*, School of Fisheries, Tech. Rept. Noe 4, 1954.
Nakatani, R. E.
1955. Effects of electroshock on some blood constituents of salmon;
I. Inorganic phosphate and hematocrit values of the blood I
of young silver salmon. Univ. of Wash., School of Fisheries,
Tech. Rept, No. 15, 1955.
Newman, H. W.
1956. Study of the effects of magnetic fields on salmon, N.Pac.Div.,
Corps of Engr. progress report on Fisheries-Engineering Research
Program, Nov. 1956.
257
-------
B I 0 L 0 G I GAL (Cont'd)
(Swimming Ability, Size, Behavior, Etc.
Pavlov, D. S.
1970. Optomotor Reaction and Peculiarities of Orientation of Fish in
Flowing Water, Moscow, USSR 1970.
Pavlov,- D. S. and A. M. Pakhorukov
1973. Biological basis of protecting fish from entry into water intake
structures. Pishchevaya Promyshennost', Moscow, 1973," 208 pp.
Rees, W. H.
1956. Determination of the vertical and horizontal distribution of
seaward migrants, .Baker Dam, N.Pac. Div., Corps of Engrs.
progress report on Fisheries-Engineering Research Program,
' Nov. 1956.
Robbins, T. W.
1970. Studies of Fishes in the Muddy Rnn .Pumped Storage Reservoir and
Connecting Waters - Summary - Ichthyological Associates,
Misc. Report No. 4, May 1, 1970, 35 pp.
Skinner, J. E.
1969. Considerations for the development of fish facilities and
operational criteria related to the Peripheral Canal, Internal
Rept., Calif. Dept. of Fish and Game, Nov. 1969 (unpublished),
Sonnichsen, J. C., Jr., B. W. Bentley, etc. al.
1973. A Review of Thermal Power Plant Intalse Structure Designs and
Related Environmental Considerations prepared for the U. Sc Atomic
Energy Commission, Div. of Reactor Development and Technology,
May 1973.
Spindler, John C.
1955. Loss of game fish in relation to physical characteristics of
irrigation-canal intakes, the Journal of Wildlife Management,
Vol. 19, No. 3, July 1955.
State of California
1974, Fish Facility Program, State of Calif., Dept. of Fish and Game and
Dept. of Water Resources, Bay-Delta Fishery Project, Monthly
Progress Reports - April 1974, p. 4; May 1974, pp 3 & 4; June 1974
pp. 5-8; July 1974, pp 3-5; August 1974, pp 4-6; Sept. 1974, pp 6-8;
Oct. 1974, p. 6.
Thomas, A. E., J. L. Banks and D. C. Greenland
1969. Effect of yolk sac absorption on the swimming ability of
fall chinook salmon, American Fisheries' Society Transactions
Vol. 98, No. 3 - July 1969.
258
-------
BIOLOGICAL (Cont'd)
(Swimming Ability, Size, Behavior, Etc.)
Esipliaev, A. S.
1973. Fish protective screening devices with water diversions
Leningrad Polytechnic Institute, Dept. of Hydraulics,
USSR 166 pp.
U. S. Environmental Protection Agency ', '
1973. Development document for proposed best technology available for mini-
mizing adverse Environmental Impact of Cooling Water Intake-Structures,
Ue S. Environmental Protection Agency, Dec. 1973.
University of Washington
I960. A study to determine the effects of electricity on salmon and *teal-
head trout, N.Pac. Div., Corps of Engr., Progress Report on
Fisheries-Engineering Research Program, July 1960.
Verhoeven, L. A., G. L. Hoard, and R. E. Nakatani
1955. A summary report' on research accomplished to date and future plans
related to the contract between the Univ. of Wash, and the Corps.
of Engineers "For conducting a study to determine the effects of
electricity on salmon and steelhead trout," presented to the
Technical Fisheries Engineering Advisory Committee on Jan. 17, 1955.
Univ. of Wash., School of Fisheries, 6 pp. (hectograph).
Verhoeven, L. A. and G. L. Hoard
1956. A study to determine the effects of electricity on salmon and steel-
head trout. Progress Report on Fisheries Engineering Research
Program, N. Pac. Div., Corps of Engineers, U. S. Army, Nov..1956,
pp. 139-153.
Verhoeven, L. A. and G. L. Hoard
Effects on young salmon of electric shocks composed of direct
current superimposed. Univ. of Wash., School of Fisheries
(manuscript) '
Verhoeven, L. A., G. L. Hoard, and R. E. Nakatani
Injurious and mortal effects of electric currents on young salnon.
Univ. of Wash., School of Fisheriesj Tech. Report. No. 16.
Verhoeven, L. A., G. L. Hoard and R. E..Nakatani
1956. Effects of low-frequency-pulsated-square-wave direct current'on
young salmon. University of Wash., School of Fisheries, Technical
Report No. 19, 1956.
Wunder, W.
1950. Die Seitenline, ein besonders wassersirihesorgan der fishe.
Allgemeine Fischeri - Zeitschrift, Bd. 75, No. 4, pp. 97-99.
259
-------
FISH-PASSAGE RESEARCH PROGRAM
1964 - The Accelerated Fish-
Passage Research Program
U. S. Bureau of Commercial
Fisheries - Seattle, Wash.
Five volumes, December 1964.
Contains the following list of
papers as related to screening
of fish by author:
Exploratory Research on Guiding Juvenile Salmon - Bates
Exploratory Experiments on the Deflection of Juvenile Salmon by
Means of Water and Air Jets - Bates, VanDerwalker
Preliminary Tests With Louvers in the Troy Laboratory on the
Grande Ronde River - Bates, Vinsonhaler, Sutherland
A Preliminary Study on the Maintenance of an Inclined Screen - Bates
Velocity-Matching Traveling Screens for Juvenile Migrant Collection -
Bates, VanDerwalker
Activity Cycles of Juvenile Salmon - Blahm
A Report on a Preliminary Engineering Study of a Downstream Migrant
Fish Screening Facility on the Snake River - Cornell, Kowland,
Hayes and Merryfield Consulting Engineers.
Fish Handling Methods Employed for Fingerling Mortality Studies in
Kaplan Turbines - Duncan, Jensen, Long,Marquatte
The Vertical Distribution of Cbho Smolts in the Forebay of Merwin Dam
in 1964- Erho.(Washington Department of. Fisheries)
A Fish-Sanctuary Barge for Research in Turbines - Farr, Marquette
Effects of Water Temperature on Swimming- Performance of Eingerling
Sockeye Salmon (Summary) - Groves
Comparative Response of-: Blinded and Non-Blinded Fingerling Salmon
to a Louver Barrier and to a Sharp Increase in Water Velocity -
Gerold, Niggol
Comparison of Alternative Fish Hauling Costs,JMiddle Snake River Basin -
Lane (Consulting Services Corp., Seattle, Wash.)
260
-------
Guiding Salmon Fingerlings With Horizontal Louvers - Larsen
Day-Night Occurrence and Vertical Distribution of Juvenile Salmonids
and Lamprey Aomocoetes in Turbine Intakes (Summary) - Long
Effect of Lighted Conditions at a Surface Bypass on the Vertical
Distribution of Fingerling Salmonids in a Turbine Intake (Summary) -
Long - .
Increasing the Percentage of Fingerlings Entering Intake Gatewells —-
A Proposal - Long
Evaluation of Equipment for Recovering Fish Passed Through,Kaplan
Turbines - Marquette, Duncan, Jensen, Long
Timing, Composition, Quantity, and Vertical Distribution of Debris
in the Snake River Near Weiser, Idaho—Spring 1964 - McConnell,
Monan
A Field Test of Electrical Guiding and Louver Deflection Combined
Into a Single Guiding System - Monan, Pugh
Horizontal and Vertical Distribution of Downstream Migrants,
Snake River, Spring 1964 - Monan
Response of Juvenile Migrants to Flow Accelerations - Niggol
Effect of Water Velocity on the Fish Guiding Effectiveness of an
Electric Field - Pugh, Monan, Smith
Horizontal and Vertical Distribution of Yearling Salmonids in the
Upper End of Mayfield Reservoir - Pugh, Smith
Guiding Juvenile Salmonids With Long Lead Nets at the Upper End of
Brownlee Reservoir - Pugh, Monan
Porous Plate Studies 9Summary) - Richey, Murphy (Univ. of Washington
Hydraulics Laboratory)
A Funnel Net for Recovering Fish Below Turbines - Snyder, McNeely
Passage of Downstream Migrating Salmonids Through an Orifice in a Turbine
Intake Gatewell at Bonneville Dam - Snyder '
Exit Rate of Chinook and Coho Salmon Yearlings From a Turbine Intake
Gatewell at Bonneville Dam - Snyder
Responses of Juvenile Chinook Salmon to Pressure Changes - Tarrant
Studies on the Responses of Fish to Low Frequency Vibrations -
VanDerwalker
Exploratory Tests of Velocity Selection as a Means of Guiding
Juvenile Fish - Vinsonhaler, Sutherland
261
-------
u.
Partial List
Of
S. Patents on Fish Screens
'Patent No.
630,769
648,505
886,797
916,570
951,635
971,492
988,033
992,563
993,074'
997,157
1,002,208
1,007,630
1,011,119
1,012,500
1,038,087
1,054,566
1,063,316
1,063,344
1,064,335
1,065,724
1,076,483
1,080,415
1,080,488
1,095,434 '
1,095,697
1,095,698
1,098,489
1,121,075
1,132,041
1,143,147
1,143,496
1,147,301
1,166,628
1,178,428
1,180,564
1,185,188
1,195,988
1,215,781
1,215,817
1,225,160
1,232,794
Drum Screen
Electric Fishing Apparatus
Drum Screen
Bar Screen w/Mechanical Cleaner
Drum Screen
Drum Screen
Screen Panels - Self Cleaning
Slightly Inclined Vertical Belt Screen
Drum Screen
Drum Screen
Drum Screen
Drum Screen
Drum Screen
Drum Screen
Drum-Panel Combination
Drum Screen
Drum Screen
Inclined Belt Screen
Drum Screen
Drum Screen
Inclined Belt Scre'en
Drum Screen
Rotating Screen Panels
Drum Screen
Chain Fence Fish Guide
Chain Fence Fish Guide
Inclined Belt Screen
Rotating Screen Panels
Fish Trap Screen
Horizontal Traveling Screen
Bar Screen With Cleaner
• Hexagon Drum Screen
Drum Screen
Plate-Fish & Barrier w/Special Baffles
Disk Screen
Drum Screen
Square Drum Screen
Double Plate Perforated Screen
Rotating Vertical Paddles
Fish Gate - Bar Screen
Bar Screen
262
Date
August 8, 1899
May 1, 1900
May 5, 1908
March 30, 1909
March 8, 1910
September 27, 1910
March 28, 1911
May 16, 1911
May 23, 1911.
July 4, 1911
August 29, 1911
October 31, 1911
December 5, 1911
December 19, 1911
September 10, 1912
February 25, 1913
June 3, 1913
June 3, 1913
June 10, 1913
June 24, 1913
October 21, 1913
December 1\ 1913
December 2, 1913
May 5, 1914
May 5, 1914
May 5, 1914
June 2, 1914
December 15, 1914
March 16, 1915
June 15, 1915
June 15, 1915
July 20, 1915
January 4, 1916
April 4, 1916
April 25, 1916
May 30, 1916
August 29, 1916
February 13, 1917
February 13, 1917
May 8, 1917
July 10, 1917
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Patent No.
Date
1,234,894 Drum Screen
1,241,708 Rotating Panel Screen
1,243,525 Vertical Belt Screen '-.--;-
1,252,617 Vertical Belt Screen
1,254,602 Bar Screen
1,255,741 Bar Screen |
1,262,007 Bar Screen :
1,263,691 Vertical Screen Panels w/Automatic Cleaning
1,265,251 Flap Gate Screen
1,265,508 . Vertical Belt Screen
1,266,331] Bar, Drum Type Screen
1,269,058 Bar Screen
1,276,374 Vertical Drum Screen
1,302,839 Horizontal Bar Screen
1,346,881 Rotating Panel Screens
1,420,508 Drum Screen
1,451,394 Skimmer, Noise [
1,468,320 Noise w/Bells
1,486,034 Panel - Drum Screen i
1,493,405 Fish Screen Gate
1,551,967 Screen Panel
1,554,442 Drum Screen
1,596,310 Bar - Noise Screen
1,658,875 Bar Screen
1,663,398 Drum Screen
1,692,451 Inclined - Vertical Belt Screen
1,804,989 Screen Panels on Water Wheel
1,825,169 Inclined Screen (Slope Downstream)
w/Flow Control
1,875,790 Belt Screen
2,010,601 Electric Fish Screen
2,056,445 " Drum Screen
2,074,407 - Square Drum Screen •
2,095,504 Inclined Belt Screen w/Hinged Panels
2,162,325 Inclined Belt Screen
2,240,642 Drum Screen
2,309,472 Inclined Shaker Screen
2,324,296 - Drum Screen
2,328,297 Drum Screen
July 31, 1917 '
October 2, 1917
October 16, 1917
January 8, 1918
January 22, 1918
February 5, 1918
April 9, 1918
April 23, 1918
May 7, 1918
May 7, 1918
May 14, 1918
June 11, 1918
August 20, 1918
May 6, 1919 .
July 20, 1920
June 20, 1922
April 10, 1923
September 18, 1923
March 4, 1924
May 6, 1924
September 1, 1925
September 22, 1925
August 17, 1926
February 14, 1928
March 20, 1928
November 20, 1928
May 12, 1931
September 29, 1931
September 6, 1932
August 6, 1935 ,
October 6, 1936
March 23, 1937
October 12, 1937
June 13, 1939
May 6, 1941
January 26, 1943
July 13, 1943
August 31, 1943
263
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