ML17054A529
| ML17054A529 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 01/31/1984 |
| From: | LAWLER, MATUSKY & SKELLY ENGINEERS |
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| NUDOCS 8403200240 | |
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Text
NIAGARA MOHAWK POWER CORPORATION Syracuse, New York EVALUATION OF THE ANGLEO SCREEN FISH OIVERSION SYSTEM AT OSWEGO STEAM STATION UNIT 6 RESEARCH PROJECT No. EC 104 April 1981 - March 1983 January 1984 LMS/-84/0011IC191/058 Prepared By LAWLER, MATUSKY 5 SKELLY ENGINEERS Environmental Science 5 Engineering Consultants One Blue Hill Plaza Pearl River, New York 10965 8403200240 840315 PDR ADOC5 05000410
'~ ",A PDR
I TABLE OF CONTENTS ont1nue
~Pa e No.
4.7 Dark-Induced Diversion 4.0-21 4.7.1 Methods and Materials 4.0-21 4.7.2 Results 4.0-23 5.0 TOTAL PLANT EFFICIENCY 5.0-1 6.0 POTENTIAL FOR RECIRCULATION 6.0-1 7.0 ASSESSMENT OF PREDATOR POPULATION 7.0-1 8.0 DISCUSSION 8.0-1 REFERENCES CITED I,nwlcr, Mnlnskv O'kcllv I'.nginccrs
e LIST OF FIGURES Fi ure No. Title ~Pe e No.
2.0-1 Location of Intake and Oischarge Structures 2.0-2 2.0-2 Offshore Intake Structure 2.
0-3'.0-5 2.0-3 Plan of Screenwell Layout
~ - ~
2.0-4 Fish Return Pipe 2.0-7 2.0-5 Oswego Steam Station Unit 6, Schematic 2.0-10 4.0-1 Lake Collection and Holding Nets 4.0-17 Lawler, iblatnsky O'kelly 1',ngineers
LIST OF TABLES Table No. Title ~Pa e No.
S-1 Total Diversion Efficiency of Selected S-4 Species S-2 Monthly Total Plant Efficiency by Species S-5 S-3 Diversion System Effectiveness for S-7 Alewife, Rainbow Smelt, and White Perch by Size Class 2.0-1 Trash Rack Velocities, Oswego Steam 2.0-11 Station Unit 6 2.0-2 Velocities at the Two Eastern Impinge- 2.0-12 ment Screens 2.0-3 Velocities at the Two Western Impinge- 2.0-13 ment Screens 2.0-4 Effect of Tempering on Screenwell 2.0-15 Velocities 2.0-5 Velocities at the Secondary Screen 2.0-17 2.0-6 Secondary Screenwell Velocities Under 2.0-18 Various Operating Conditions 3.0-1 Sampling Schedule: 3.0-7 April 1981 - March 1983 3.0-2 Species List of Organisms Collected at 3.0-8 the Oswego Steam Station 3.0-3 Estimated Monthly Impingement 3.0-9 3.0-4 Estimated Monthly Impingement by 3.0-11 Si ze Cl ass 3.0-5 Alewife Impingement Length Frequency 3.0-12 3.0-6 Rainbow Smelt Impingement Length 3.0-13 Frequency 3.0-7 White Perch Impingement Length Frequency 3.0-14 1v Lnwlor, Matxisky O'kolly I',nginoers
LIST OF TABLES onto'ue Table No. Title ~Pa e No.
3.0-8 Relative Impingement on Each of the 3.0-16 Five Vertical Traveling Screens 3.0-9 Estimated Monthly Entrapment Rate 3.0-19, 3.0-10 Primary Diversion Efficiency of Selected 3.0-20 Species 3.0-11 Secondary Diversion Efficiency of 3.0-21 Selected Species 3.0-12 Estimated Monthly Impingement by 3.0-24 Diversion System 3.0-13 Length Frequency of Rainbow Smelt in 3.0-25 Impingement Collections 3.0-14 Length Frequency of Alewife in 3.0-26 Impingement Collections 3.0-15 Length Frequency of White Perch in 3.0-27 Impingement Collections 3.0-16 Total Diversion Efficiency of Selected 3.0-28 Species 3.0-17 Estimated Numbers for Alewife, Rainbow 3.0-30 Smelt, and White Perch Entrapped, Impinged, and Diverted by Size Class 4.0-1 Initial Viability Classification as 4.0-7 Live or Dead Following Diversion 4.0-2 Viability Testing 4.0-9 4.0-3 Alewife, Rainbow Smelt, and White 4.0-10 Perch Long-Term (96-hr) Survival by Size Class 4.0-4 Alewife, Rainbow Smelt, and White 4. 0-11 Perch Survival Corrected for Initial Mortality I,nivlcr, Mutiisky P'kolly I nginoors
LIST OF TABLES ont~nued Title Page No.
Survival Subsequent to Passage Through 4.0-15 the Diversion System Survival Results of Fish Collected at 4.0-19 the Offshore Discharge'lewife and Rainbow Smelt Survival 4.0-24 Subsequent to Dark-Induced Passage Through the Diversion System Survival Subsequent to "Dark-Induced" 4.0-25 Passage Through the Diversion System monthly Total Plant Efficiency by 5.0-2 Species Estimated Numbers of Fish Returned 5.0-3 Alive to Lak Ontario Diversion System Effectiveness for 5.0-5 Alewife, Rainbow Smelt, and White Perch by Size Class Estimated Numbers of Fish Returned 5.0-6 Alive to Lake Ontario Using Dark-Induced Diversion Diversion System Effectiveness for 5.0-7 Alewife and Rainbow Smelt by Size Class Using Dark-Induced Diversion Rainbow Smelt Recirculation Study 6.0-2 Predation Survey Sample Dates for 7.0-2 1982 Fish Collected in 12.7-cm (S-in.) 7.0-4 Stretch-Mesh Gill Net vi Lnivlcr, Matusky 9'kclly I'.nginccrs
EXECUTIVE
SUMMARY
The studies reported herein were undertaken by Lawler, Matusky 5 Skelly Engineers (LMS) for Niagara Mohawk Power Corporation (NMPC) as a two-year research evaluation of the effectiveness of the fish diversion system at Oswego Steam Station Unit 6. The effectiveness of the system is defined by the ability of the system to divert, alive, the fish entrapped in the circulating cooling water from the primary screenwell back to the source water body. The Oswego installation represents the first full-scale application of the angled screen technology in an operating electric generating sta-tion. Concurrent investigations of an angled screen diversion system are now under way at Central Hudson Gas E Electric Company's Oanskammer Generating Station.
The fish diversion and transport system installed at Oswego Unit 6 is based on simulations and biological testing of the system com-ponents conducted over several years at Alden Research Laboratories by Stone and Webster Engineering (S5W). Unit 6 is an oil-fired steam qenerator with a rating of 816 MWe and a maximum gross output of 890 MWe. Cooling water (20.5 m /s [724 cfs]) is taken from Lake Ontario via a submerged velocity cap inlet, circulated through the condensers, and returned to the lake through a submerged jet diffuser. Fish entering the screenwell with the cooling water flow pass through trash racks and encounter four flush-mounted traveling water screens angled toward a bypass (Figure 2.0-3).
The bypass flow from the primary screenwell enters the suction side of the primary jet pump. This pump discharges into a secondary screenwell where the fish encounter a single flush-mounted traveling screen angled toward another bypass. The secondary bypass leads to the secondary jet pump, which in turn discharges either to the sam-pling basin or to a pipe embedded in the roof of the intake tunnel.
S-1 l.nwlor, hintnsky 8 Bkc:lly 1',nginoors
The secondary diversion system, consisting of the secondary screen-well and secondary bypass, serves to minimize the volume of -water used to transport the diverted fish back to the lake.
The transport pipe extends offshore for a distance of approximately 300 m (1000 f t) where it rises vertically and terminates as a horizontal discharge approximately 2 m (6 ft) off the bottom of Lake Ontario.
Fish that failed to divert across tHe screens and into the bypass were collected from the vertical traveling screens creens (impingement),
( tj, while those diverting were collected downstream of the bypass from the sampling basin. The relative numbers of fish impinged vs diverted provided an estimate of diversion efficiency. Lonq-term (96-hr) viability observations were conducted on a subsample of the diverted fish to estimate the proportion of diverted fish that would survive upon return to the source water body. Viability obser-vations were primarily conducted prior to transport offshore but limited viability observations conducted offshore provided results consistent with the larqer data base from onshore sampling. The integration of the total entrapment rate, the diversion efficiency 7 and the estimated survival provided an estimate of the total number of fish returned alive to the lake.
The fish entrapment rate demonstrated a definite seasonal pattern in species composition and population dynamics. Spring collections were dominated by adult alewife and rainbow smelt; fall collections were dominated by young-of-the-year (YOY) rainbow smelt, alewife, and gizzard shad. While the same species dominated in both years, their abundance differed widely. Adult alewife entrapment was high
()118 fish/hr) in the spring of 1981, while that of adult rainbow smelt was low ((15 fish/hr). In the fall and early winter of 1981, YOY rainbow smelt predominated, with a mean monthly abundance in S-2 I.awlor, M:iLitskv 6" Bkc:lly I',nginoors
December exceeding 160 f i sh/hr. The spring of 1982 saw smal 1er numbers of adult alewife compared to the previous spring, but abundances of adult rainbow smelt were substantially higher than the previous spring. The fall of 1982 relative to the fall of 1981 produced very low abundances of all YOY fish except smallmouth bass.
The effectiveness of the diversion system (total diversion effi-ciency [TDE]) is defined as the ratio of the number of fish entering the secondary diversion bypass (diversion rate) to the number of fish entering the primary screenwell (entrapment rate).
Alewife TOE varied widely, from zero to 97.8X. The primary vari able affecting alewife diversion was the condition of the population when entrapped. The difference between the 91.0-97.85 TOE in spring of 1981 and the 40.9-80.3X TDE in spring of 1982 can be attributed to
'the poor condition of the alewife stock (Section 3.5.2).
Rainbow smelt TOE also varied over the duration of the study. The lowest TDE (43.8X) was reported, in the summer of 1982, while the highest value was in the early spring of 1981 when the prespawn adults were diverted at a TOE of 98.8X. Like the alewife, rainbow smelt diversion was related to condition of the entrapped popula-tion.
The remaining eight species showed TOEs ranging from 49.8X for mottled sculpin to 100K, for smallmouth bass (Table S-1).
Long-term survival observations (96-hr) were applied to the TDE to estimate the number of diverted fish that subsequently survived or the total plant efficiency (TPE). Differential TPE results were observed for YOY and adult alewife, rainbow smelt, and white perch.
Typically, the YOY survivals were lower than the corresponding adult survivals (Table S-2).
S-3 I,nwlor, illatnsky O'iknlly )'.nginoors
TABLE 5-1 TOTAL DIVERSION EFFICIENCY OF SELECTEO SPECIES Oswego Steam Station Unit 6 - April 1981 - Harch 1983 Apl 1981 97.8 98.8 88.1* 94.8* 92.3* 94.1* 92.6* 100* 70.4>> 49.8*
Hay 91.0 91.8>>
Jun 75.7 91.8*
Jul 83.6 91.8*
Aug 36.7 91.8>>
Sep 49.1 76.7 Oct 80.7 73.0 Nov 85.6 64.3 Oec 95.4 74.4 Jan 1982 0 72.5 Feb 40.9* 60.2 Har 40.9* 77.4 88.1>> 94.8>> 92.3* 94.1* 92.6* 100* 70.4* 49.8>>
Apr 40.9* 82.3* 84.4* 79.3* 71.9>> 82.7* 83.3* 88:8* 80.1* 71.8*
Hay 80.3 82.3*
Jun 87.6 43.8*
Jul 88.6 43.8*
Aug 66.9 55.4 Sep 66.0 76.4 Oct 72.2 82.6 Nov 88.3* 87.7 Oec 88.3* 85.5 Jan 1983 88.3>> 68.5>>
Feb 88.3>> 68.5*
Har 65 F 6 77.2 84.4* 79.3* 71.9>> 82.7* 83.3* 88.8* 80.1* 71.8*
a As a percent.
- Composited across month AX - Alewife STSH - Spottail shiner RSH - Rainbow smelt SHB - Smallmouth bass EMSH - Emerald shiner TSB - Threespine stickleback GSD - Gizzard shad YP - Yellow perch MP - Mhite perch HOTS - Hottled sculpin
TABLE -2 HONTHLY TOTAL PLANT EFFICIENCY BY SPECIES Oswego Steam Station Unit 6 - April 1981 - March 1983 HONTH Apr 1981 13.3 22.6 23.8 64.6 45.7 57.2 80.1 76.4 52.0 90.5 88.2 6.6 38.0 May 1.0 1.6 22.1 0 Jun 1.9 7.4 22.1 20.4 Jul 2.7 25.7 18.4 20.4 Aug 1.2 2.5 18.4 20.4 Sep 1.9 5.5 12.2 17.0 Oct 15.8 45.2- 23 7 32.3 Nov 16.1 27.4 11.7 20.6 Oec 13.8 26.6 5.0 20.7 Jan 1982 0 0 4.2 44.7 Feb 3.0 7.4 3.1 38.3 Har 3.0 3.4 5.0 46.3 45.7 57.2 80.1 76.4 52.0 90.5 88.2 6.6 38.0 Apr 0 6.0 /.b 57.8 43.8 54.8 62.4 67.2 43.5 81.4 78.3 7.5 54.8 Hay 0 5.9 7.1 32.7 Jun 0.7 3.1 3.8 17.4 Jul 0.7 4.3 3.8 14.1 Aug 1.1 4.2 4.8 17.8 Sep 0.9 7.5 6.1 24.6 Oct 0.4 11.8 7.8 20.4 Nov 2.0 55.8 11.1 21.7 Oec 1.4 55.8 20.4 21.1 Jan 1983 1.4 55.8 16.4 16.9 Feb 1.4 55.8 16.4 16.9 Har 1.0 41.5 18.5 19.1 43.8 54.8 62.4 67.2 43.5 81.4 78.3 7.5 54.8 As a percent.
AM - Alewife GSO - Gizzard shad RSH - Rainbow smelt YP - Yellow perch MP - Mhite perch SHB - Smallmouth bass EMSH - Emerald shiner TSB - Threespine stickleback STSH - Spottail shiner HOTS - Hottled sculpin XCombined across months during periods of low abundance.
A total of 448,870 alewife were entrapped during the two-year period, with an estimated 50,481 of these being returned offshore alive. TPE for the 12,240 YOY alewife was 8.4X as compared to 12.6X for the 38,241 adult alewife (Table S-3).
Using the same procedures for rainbow smelt, a total of 433,862 smelt were entrapped during the two-year period, with 74,807 .
of these bein e urned alive.
return System effectiveness for the 36,442 YOY smelt was 10.0X as compared to 54.3X for the adult smelt (Table S-3). More than 80K of the yellow perch and smallmouth bass
'ntrapped during the study period were returned alive.
The conclusions of the studies of the Oswego Steam Station Unit 6 angled screen diversion system can be summarized as follows.
- 1. Mechanically and hydraulically the sys syst em is n'
functiioning as designed with minimal operational problems.
- 2. Oiversion of fish across the angled scree ig y dependent upon species, their condition (i.e., physiological and/or reproductive state),
and their age or size class.
- 3. The fragile species (alewife, gizzard shad, juve-nile smelt) are more susceptible to impingement than are the hardy species (salmonids, smallmouth bass, rock bass, yellow perch).
- 4. Unless weakened by recent spawning activities, adults of a species typically exhibit a higher diversion efficiency than the younq.
- 5. Survival following diversion was also dependent upon species, their condition, and their
'ize ir aagee or class.
- 6. Survival results based on offshore collections indicated that in-plant collections provided a good estimate of ultimate survival upon on diisc h arge off-shore.
7 The condition of the alewife population at -the time of entrapment and the stresses applied to the S-6 I.nervier, Xilntnsky 8'kelly 1'.ngineers
TABLE S-3 DIVERSION SYSTEH EFFECTIVENESS FOR ALEMIFE RAINBSI SHELT AND WHITE PERCH BY SIZE CLASS Oswego Stean Station Unit 6 - April 1981 - Harch 1983 No. Entrapped 145,266 303,604 363,166 70,696 12,423 6,385 No. Impinged 39,686 53,072 107,741 4,380 1,319 445 Ko. Oiverted 105,580 250,532 255,425 66,316 11,104 5,940 No. Surviving 12,240 38,241 36,442 38,365 5,584 3,622 X Effective (TPE) 8.4 12.6 10.0 54.3 50.0 56.7 Estimate based on average monthly collection rates (No./hr) over the period April 1981 through March 1983.
b Heasured in centimeters.
population upon transport to the screenwell most likely account for the substantial differences in survival results observed in laboratory studies and the actual installation.
- 8. Overall TPE varied from 6.6 to 17.8X for the fragile species (threespine stickleback, alewife, and rainbow smelt) to 73.5 to 87.05 for the. hardy species (spottai 1 shiner, emerald shiner, small- .
mouth bass, and yellow perch).
- 9. The angled screen diversion system is an appli-cable and proven technology that will operate with minimal additional maintenance beyond that re-quired for the traditional vertical traveling screens. Its effectiveness as a mit<igation device will depend upon the species of interest, their age or size class, and the condition in which the individuals are delivered to the system.
S-8 I,nervier, hlatnsky lY Skelly I',ngineers
CHAPTER
1.0 INTRODUCTION
This report summarizes the 'results of a two-year research program to evaluate the effectiveness of the fish diversion system at Niagara Mohawk Power Corporation's (NMPC) Oswego Steam Electric Generating Station Unit 6 (OSS-6). The unit began commercial operation in July
~
with a once-through cooling water system outfitted with a fish
- 1. 80 wl 19S diversion and return system based on laboratory studies conducted by Stone and Webster Enqineering Corporation (1977).
The effectiveness of the diversion system was determined relative to a conventional once-through cooling waterr sys s t em consisting of a screenwell with vertical traveling screensn . A f is entering the screenwell of a conventional system either 'swims out against the entrapping flow (virtually impossible in an offshore intake system) or is impinged and removed by the vertical traveling screen. The principle of the diversion system is to induce the fish entering the screenwell to divert across the traveling screens and enter a bypass that wi 11 lead back to the source water body. In an effective diversion system, this process occurs with minimal harm or damage to the diverted fish.
The total plant effectiveness (TPE) of the OSS-6 diversion system is defined as the ahility of t he system to reduce or eliminate impinge-ment and to divert alive the fish entrapped in the cooling water flow from the screenwel 1 back to the source water body. Angled d' '
screens have been used at hydro stations t o iver f ish (primarily trout and salmon) from turbine intakes (Farr 1974; Marquette and Long 1971) or into a fish passage (Gunsolus and Eicher 1950. Eicher 1960; Bates and VanDerwalker 1970). The Oswego installation is 'the first full-scale application of the angled screen technology in an I,nwlor, Mntnsky lY hknlly I'.ngincor8
operatinq electric generating station. Concurrent investigations of an angled screen di version system are now undei way at Central Hudson Gas 8 Electric Company's Danskammer Point Generating Station.
To determine the effectiveness of the system, the effectiveness of the screens in diverting the organisms entrapped in the screen-well (diversion efficiency) and the mortality associated with the diversion process (survival) were,investigated. The studies con-centrated on su'rvival subsequent to passage through the diversion system but prior to transport back to the source water body. A less intensive sampling effort evaluated the ultimate survival observed upon release offshore and compared these results to the survival results based on in-plant sampling.
Chapter 2.0 of this report describes the angled screen system as well as the important hydraulic char'acteristics. Chapter 3.0.
presents the estimates of the efficiency of the primary and sec-ondary diversion systems as well as the overall efficiency of the angled screen system in diverting fish. Chapter 4.0 provides the viability data and a discussion of the observed trends. Chapter 5.0 integrates the diversion efficiency results with the viability results to estimate the total plant efficiency for selected species.
Chapters 6.0 and 7.0 summarize the results from two special studies.
Chapter 6.0 evaluates of the potential for reentrapment of diverted fish, and Chapter 7.0 summarizes the data from a study to assess predator species adjacent to the offshore fish diversion discharge relative to a control location 0.8 km (0.5 mi) away..
Chapter 8.0 summarizes the results in the previous chapters and discusses these results relative to other studies.
I.aivlor, iliatnsky O'>kolly 1'nginoors
CHAPTER 2.0 SYSTEM DESCRIPTION 2.1 SYSTEM DESIGN The design of the Oswego Unit 6 fish diversion system is based on the results of hydraulic and biological testing of the system components conducted over several years at Alden Research Labora-tories by Stone and Webster Engineering (S5W 1977).
Unit 6 is an oil-fired steam generator with a rating of 816 MWe and a maximum gross output of 890 MWe. Cooling water is taken from Lake Ontario via a submerged inlet, circulated through the condensers, and returned to the lake through a submerged jet diffuser. The intake structure is a hexagonally shaped velocity cap located approximately 370 m (1200 ft) from the existing shoreline (Figure 2.0-1). At the low water datum of 74.1 (243 ft) (International Great Lakes Datum 1955), the water is 6.7 m (22 ft) deep and the clearance between the top of the intake structure and the water surface is 3.7 m (12 ft). A 1-m (3-ft) sill at the bottom minimizes silting of the intake. Each side of the hexagonal intake has a 1.5 m high by 6.5 m wide (5 x 21,ft) aperture (Figure 2.0-2). Intake apertures are outfitted with heated bar racks to prevent the forma-tion of frazil ice. The intake is designed such that the horizontal approach velocity .is approximately 30 cm/sec (1.0 fps) at maximum circulating water flow.
The circulating water flow (cooling water, service water, and fish diversion flow) is delivered to the plant through an 11.2-m (121-ft 2 ) tunnel . The design 'circul ating water pump flow rate is 20.5 m 3 /sec (724 cfs). Since some of the pump flow is recirculat-ed through the diversion system to the screenwell, the velocity in I,nwlor, b,lalcisky 6 .>kully 1':ttginoors
SHORE LINE UNIT 6 DISCHARGE UNIT 5 INTAKE T'p UNIT 5 DISCHARGE o
/'+
(i') 7
/ EX I STI:"39
<<is@ 0g INTAKE TUNNEL UNIT 6 INTAKE 0$ 'O'E 80 HA R'808 'FIGURE 2.0-1 LOCATION Or INTA,KE AiND 0 6l l22 DlSCHARGE STRUCTURES I
SCALE: METERS
MEAN LOS WATE R Z.7 t.5 A
l.O
/il~i//~W/ Q //$///~b/p7 f~g ~( ~ i/ i~ ~~pug YA' tg YAK E SOAPY I ) OVER BORD EN I i l RO C tel E LE V AT I 0 N 6.6 SECTION A"A 0 6 F t GUR E 2.0-2 I
SCALE: tAETERS OFFSHORE INTAKE STRUCTURE UNIT NO.G OGV/EGO 8 i EAM SIAl'ICi<
ALL DIMENSlONS IH METERS N IA6ARA f~tQ(lAV'K'O'",tEI'QRF'Oi<ATION 2.0-3
the tunnel is less than 182 cm/sec (6.0 fps). The circulating water flow enters the intake screenhouse through a vertical intake shaft rising approximately 30 m (100 ft) in approximately 20 sec. From ~
there the water flows into two screenbays in the primary screenwell, each 5.2 m (17 ft) wide, with a water column depth that varies from 7.3 to 10.1 m (24 to 33 ft).
Fish entering the screenwell pass through trash racks with 7.6-cm (3-in.) clear spacings, and encounter flush-mounted traveling screens angled toward a 15-cm (6-in.) wide bypass. Each bay is I
sized to accept three 3-m (10-ft) wide traveling screens separated by 1-m (39-in.) wide concrete piers. At present, each bay is equipped with two screens, and the third opening is blocked off with stop gates for a possible future screen. The screens are angled 25 to the direction of flow, with their downstream ends converging but separated by a 1.5-m (5-ft) wide pier (Figure 2.0-3).
Two dry-pit circulating water pumps draw the flow through the screenwell. Each pump suction opening is on the centerline of a screenbay and level with the bottom of the screenwell. The bypass suction flow is designed such that the ratio of the average screen-well approach velocity to the average bypass entrance velocity is 1: 1. Each 15-cm (6-in.) wide bypass slot extends the full depth of the water column, The two slots converge in the horizontal plane as well as the vertical plane at a 45'ngle to two 0.6-m (24-in.)
diameter pipes. The two pipes become a single 0.8-m (32-in.)
diameter pipe that becomes the suction pipe of the primary peri-pheral jet pump. The mixing tube of the primary jet pump is 0.9 m (36 in.) 'in diameter, resulting in an area ratio of driving nozzle to mixing tube of 0. 18. The primary jet pump discharges to a 1.6-m (5.4-ft) wide secondary screenwell.
The secondary screenwel 1 contains one angled traveling screen identical in design to the main screens except for its depth.
2.0-4 I,nwl<<i, bxutiisl< v 8',>kc.llv I:nginoors
PRIMARY iIET !
SERVICE WATER P"MP BAY SECON ARY DIVERSION CO'IDAPY !SH PUMP SAY SCR EEH WELL ~ S DIVER..!Otl DU" rpe ir'rre~"J. g,'i DP.IVliIG FLOW ~PRIMARY qSECOtICARY JET SUPPLY PIPE FROM QI) )~JET PUMP C. W. PUMPS r' M DRI V? NC I FLOW a ~.- DRIVING FLOW I INLE'Iit I' SUCTION PIPE G STOP ATE
~. Ue'ap ~ r( ~ ~ ~ ~ ~ ~
COLL ECTION BASIN TRAvEL>NG
-c'3S CR
~ PR I I I A RY DIVERSION AAS'g M
Cl RCULAT I4G
J';TR PUMP g Wv:
' eYPJSS(TYP)
SCREEN-WELL RZCK'-
IH TAK:
~
rJS r~lp TUN il E L
~ rFI
~ lo r%
/~el, TRAVELING SCREEHS TR<<"8'8 INTAKE
@3 r
I DUCT'TOP PRIMARY FISH DIVERSION GATE RACK S LUICE GATE SHAFT
>~~ P> r.
I I
~ 4s ~ 1'i TEMPER IHG F LOW FIGURE 2 0-3 0 IP2 5.?
PLAN OF SCREENWELL LAYOUT SCALE: tAETERS UNIT NO.G- OSWEGO STEAM STATION
The water depth in the secondary bay varies from 2.4 to 4.6 m (8 to 15 ft), depending on lake elevation and the number of operatin :ing pumps. Most of the water discharged from the primary jet pump flows through the secondary screen and is returned to the primary screen-well through a 1. 1-m (42-in.) diameter pipe. The fish move across the secondary screen into another 15-cm (6-in.) wide bypass slot.
The secondary bypass slot converges in the vertical plane to a 46-cm (18-in.) diameter pipe. At the secondary jet pump, this pipe reduces to a 43-cm (17-in.) diameter suction pipe. The mixing tube of the secondary pump is 51 cm (20 in.) in diameter, yielding an area ratio of driving nozzle to mixing tube of 0.22. The ratio of the average secondary bay approach velocity to the average secondary bypass velocity varies from 1:1 to 1: 1.3. The secondary.
jet pump discharges into a 76-cm (30-in.) diameter discharge pipe embedded in the roof of the intake tunnel for a distance of approxi-mately 280 m (925 ft) off shore where it rises vertically and terminates as a horizontal discharge approximately 2 m (6 ft) off the bottom and 83 m (270 ft) from the intake (Figure 2.0-4).
Downstream of the secondary jet pump and prior to leaving the screenhouse, the discharge flow can be diverted into a 2.4 x 2.4 m (8 x 8 ft) sampling basin. A pair of electrically driven gate valves direct the flow either off shore during normal operation or H
into the basin during sampling. A description of the sampling basin is provided in Section 3. 1.1.
2.2 PHYSICAL PERFORMANCE TESTING As part of the evaluation of the system operation, a study was conducted to evaluate the physical performance of the diversion system relative to the design parameters discussed in Section 2. 1.
This performance testing was divided into three tasks: (1) documen-tation of velocity distributions, (2) verification of flow through 2.0-6 I awvlc'r ill ctctskv 6" '>k('lly I'nginoors
OFFSHORE INTAKE
>L F>SN OlSCNAROE H022LC INTAKE TUNNEL
+e SS'i24 20>> g
,) N Q S RCENWCLL YO t
Q I>l KQY PLAN CIRC V(ATER INTAKE TUNNEL IIO SCALE.
FL'CL 226 0 I>OTTO>,I OF LAiC ~
~FISH O>SC><ARGE LL 22>ii" + ROE ZL E
~~
.i)4~4.
IN> AiE S)>AF I WP EI.
FISH I2I 0 RETURN S>>AI T
'o 78 A> PI P E PEL 3 '-6 WP EL l>S .0 EL >0>.8 SLOPE OCTIOII >NTAKC TUNNEL 0 5 IO l5 20 25 30 35 FEET I
0 I 2 3 4 5 IO METERS J
FiGuRE 2.0-4 FISH RETURIV PIPE UNIT NO. G " OSWEGO STEAM SSATION 2.0-7
the jet pumps and t~ ansport pipe, and (3) determination of the flow rate into the fish sampling basin relative to the discharge to the lake.
2.2.1 Velocity Distributions Velocity measurements were taken at the trash racks and at each of the five traveling screens - four, in the primary diversion system and one in the secondary. Measurements were conducted under two-pump operation with the tempering gates open or closed. All valves on the jet pumps were opened completely and the total discharge flow was directed to the lake.
The velocity measurements were made with a Marsh-McBirney Model 511 electromagnetic water current meter. This instrument senses the two orthogonal components (two channels) of flow in a plane normal to the longitudinal axis of the probe.
Measurements made at the trash racks were conducted by mounting the probe on a specially designed frame that maintained proper probe orientation, i.e., one channel perpendicular to the bar racks and the other tangent to it. The frame and probe were then lowered to the desired depth and measurements were recorded.
Measurements performed at thy traveling screens were conducted by mounting the probe directly on the face of the screen and rotating the screen in reverse unti 1 the probe was at the desired depth.
The probe was located 25 cm (10 in.) in front of the trash rack or screen.
Because of the limited space between the traveling screens and the concrete floor, the velocity probe had to be mounted on the screen from inside the screenwell. This was accomplished by LMS personnel 2.0-8 I.nwlv.r, 51;iliiskv FK P>k<:lly I',nginoors
positioned in a boat within the screenwell. The size of the boat and the difficulty of operating it, under these conditions pre-cluded measuring at the downstream extremities of the screens where the primary screenwell tapered to the 15-cm (6-in.) bypass. The same factors allowed for the measurement of only one lateral loca-tion within the secondary screenwell.
At each location of the probe, five measurements and the veloc-ity range (at a 1-sec time constant) observed over a 45-60 sec interval were recorded for each channel. A schematic showing the screen numbering system is provided in Figure 2.0-5. The mean velocities for each set of measurements at a given location are used for presentati'on'urposes. Velocities at the trash racks (Table 2.0-1) typically decrease with depth. Velocities in the upper 4 m
( 13 ft) of the water column exceeded 20 cm/sec (0.65 ft/sec), while those in the lower half were less than half those found near the surface. Non-uniform flow was evident. Velocity measurements could not be performed under tempering conditions becai se of excessive turbulence. Ouring tempering, water shoots from the northeast side of the primary screenwell across the bottom of the screenwell, impacts on the northwest wall of the primary scruenwell, and re-hounds across the screenwell to the surface. ') high observed surface current runs across the screenwell from no~ thwest to south-east.
The results of the measurements performed on the four screens located in the primary screenwell (Tables 2.0-2 and 2.0-3) indicate flow perpendicular to the screens between 7.0 and 19.8 cm/sec (0.22 to 0.65 ft/sec), with most measurements falling between 12 and 13 cm/sec (0.39 to 0.42 ft/sec). There are no areas of reverse flow and the velocities are within the range of variations expected in large open channels.
2.0-9 I,nwlor, i>latcisky 9>k~:lly linginoers
FIGURE 2.0-5 OSWEGO STEAM STATION UNIT 6 Schematic LAKE SAMPLING BASIN (SB) PRIMARY SCREENWELL INTAK E SECONDARY ET PUMP E$ T fA$ Rf(jK EAST BA R ACK SCREEN No. 5 PRIMARY JET PUMP SCREEN No. 4 SCREEN No. 1 SCREEN No. 3 SCREEN No. 2 WEST PUMP (2) EAST PUMP (1)
NOT TO SCALE 2.0-10
0 TABLE 2.0-1 TRASH RACK VELOCITIES (cm/sec)
Oswego Steam Station Unit 6 OEPTH (m) CHANNEL WE WEST TRASH RACK ME N W T,,
EAST TRASH RACK N N 0.2 -25.8 -16. 0 -40.8 -27.5 -24.8 -31.0 -30.0 -28.6
-23. 6 -35.0 9.4 + 3.2 +18.0 +21.2 0.6 -30.6 -21.4 -29.0 -27.0 -20.2 -27.6 -27.4 -25.1
-11.2 -22.2 -13.4 5.4 +16.0 + 7.6 2.1 -29.8 -19.0 -22.4 23 ~ 7 -27.6 -25.2 -29.4 -27.4
- 1.2 + 8.4 + 1.0 - 8.6 +10.4 + 7.2 4.3 -22.4 -24.4 -24.8 -23.9 -25.6 -20.0 -17.2 -20.9
+15.0 +15.8 + 8.6 - 9.2 -13.2 - 2.2 6.4 - 3.8 -12. 2 -17.4 -11.1 -19.2 -13.4 - 9.6 1
+ 7.0 +12.8 + 3.4 - 3.6 6.6 - 1.6 8.5 + 3.6 - 2.6 - 2.0 - 0.3 - 5.6 + 6.8 + 8.8- + 3.3
+ 7.6 - 3.6 + 3.6 + 4.2 + 2.8 0.8 Channel 1 - Velocity perpendicular to the trash rack: (+) South to north (outflow)
(-) North to south (inflow) 2 - Velocity parallel to the trash rack: (+) East to west
(-) West to east See Figure 2.0-5.
TABLE 2.0-2,:
VELOCITIES (cm/sec) AT THE TWO EASTERN IMPINGEMENT SCREENS Oswego Steam Station Unit 6 SOUTHEAST SCREEN NORTHEAST SCREEN (No. 2) (No. 1)
OEPTH M N MEAN (m) CHANNEL SOUTH CENTER NORTH RESULTANT SOUTH CENTER NORTH RESULTANT 0.5 NA -13.6 -12.8 39.3 -13.4 -19.8 -17.6 39.1 NA -33.4 -40.6 -32.0 -30.4 -42.8 1.9 NA -13.0 -14.4 38.7 -12.6 -16.0 -13.2 37.5 NA -33.8 -38.6 -30.0 -33.8 -40.6 4.3 NA -13.8 -13.8 38.4 -12.8 -17.2 -12.8 35.3 NA -32.8 -38.8 -23.4 -35.0 . -38.2 6.1 NA -14.2 -12.4 37.3 -12. 8 -15.4 -12.6 35.4 NA -31.8 -37.8 -27.6 32 ~ 2 -38.2 7.9 NA -16.4 -16.6 36.9 -j.2. 0 -14.6 -13. 0 34. 8 NA -32.8 33 ~ 2 -27.2 -33.2 -36.2 a
See Figure 2.0-5 b
Channel 1 - Velocity perpendicular to the screen: (-) Through the screen (inflow)
(+) Away from. the screen (outflow) 2 - Velocity parallel to the screen: (+)
( Away from the bypass Toward the bypass c
Mean resultant represents vector sum of both channels.
NA - Not accessible.
TABLE z. -3 VELOCITIES (cm/sec) AT THE TWO WESTERN IMPINGEMENT SCREENS Oswego Steam Station Unit 6 NORTHWEST SCREEN SOUTHWEST SCREEN DEPTH (No. 4 (No. 3 AN MEAN (m) CHANNEL NORTH CENTER SOUTH RESULTANT NORTH CENTER SOUTH RESULTANT 0.5 -12. 6 -16.0 -13.8 37.0 -13.0 -12.4 NA 41.9
-37.8 -37.8 -26.8 -42.6 -37.2 NA 1.8 -11.8 -15.4 -11.6 32.5 -12.2 -10.8 NA 36.9
-35.4 -30.4 -23.4 -40.6 -29.4 NA 4.3 - 8.0 -13.6 -13.6 33.6 -12.2 -11.0 NA 33.6
-38.4 -32.0 -23.0 -33;2 -29.8 NA 6.1 - 9.2 -15.0 -11.8 36.5 -13.2 -11.4 NA 36.1
-43.6 -34.0 -25.2 -35.2 -32.6 NA 7.9 - 7.0 -12.6 -10.6 49.4 -14.8 -11 ' NA 37.8
-65.0 -51.6 -27.8 -35.0 -35.8 NA See Figure 2.0-5.
b - Velocity perpendicular to the screen:
Channel 1 (-) Through the screen (.inflow)
(+) Away from the screen ('utflow) 2 Velocity parallel to the screen: (+) Away from the bypass
(-) Toward the bypass c
Mean resultant represents the vector sum of both channels.
NA - Not accessible.
The velocity parallel,to the screen was between 23.0 and 65.0 cm/sec (0 .75 to 2 .1 ft/sec), with most measurements between 29.0 and 38.6 cm/sec (0 .95 and 1.24 ft/sec). With the exception of the high velocities (65.0 and 51.6 cm/sec [2.13 and 1.69 ft/sec]) measured along the bottom of the northwest screen (No. 4), the velocities recorded parallel to the screens are near the 30 cm/sec (1.0 fps) design criteria set by SEW. The resultant velocity, or the vec'tor sum of the perpendicular and tangent velocity components, averaged between 32.5 and 49.4 cm/sec (1.07 and 1.62 ft/sec). This repre-sents the actual approach velocity to which a fish is subjected in the near field of the screen.
The actual water depth in the screenwell during the survey was 9.6 m (31.7 ft) and the maximum depth at which a measurement was taken was 7.9 m (25.9 ft). A protective plate or boot on the bottom of the vertical traveling screens provided a quiescent area 1 to 1.5 m (3 to 5 ft) deep from the bottom of the screenwell to the top of the protective plate where the water started pa~sing through the screen. The piping system servicing the high-pressure sand-wash system also contributed localized disruptions to the uniform flow f
patterns within the screenwell. Several 20-mm (8-in.) diameter pipes extend vertically along the center wall from above the water
, surface to the bot'tom of the screenwell and across the screenw'll floor. Their position, approximately 1.5 to 2.4 m (5 to 8 ft) upstream of the bypass, undoubtedly produced localized turbulence that could not be documented by the velocity measurements ("ee Section 3.4.2).
Table 2.0-4 illustrates the effect that tempering has on the velocity observed at the screens. Two screens, one at the apex (No.
3), and the other at the upstream end of the screenwell (No. 1),
were chosen to show the effect. The measurements were made at the centerline of each screen. Tempering created a lesser effect on the 2.0-14 I,nwler, ihlntnskv K< P>kelly I'.ngineers
TABLE 2.0-4 EFFECT OF TEMPERING ON SCREENWELL VELOCITIES Oswego Steam Station Unit 6 NORTHEAST SCREEN SOUTHWEST SCREEN No.1 No. 3 fCEH'f= Cfe DEPTH TEMPERING TEMPERING m CHANNEL L 0.3 -17. 7 -14.0 -15.2 -20.1
-30.8 -32.9 -39.3 -67.1 1.5 1 -17.7 -10.4 ND ND 2 -32.0 -21.3 ND ND 2.7 -17.7 -12.8 1 -12.5 -17.7
-34.1 -23.8 .2 -32.6 -51.2 5.2 -16.2 - 9.1 -12.8 -17.7
-30.5 -24.4 -36.6 -49.4 6.4 -15.5 - 9.1 -13.7 -21.3
-30.5 -18.3 -35.0 -44.2 7.6 -16.5 -15.2 -12.2 -18.9
-32.0 -14.6 -35.7 -38.7 Figure 2.0-5.
Channel" 1 - Velocity perpendicular to the screen:
(+) Away from the screen (outflow)
(-) Through the screen (inflow) 2 - Velocity parallel to the screen:
(+) Away from the bypass
(-) Toward the bypass ND - Not determined.
2 '-15
through-screen velocity than on the parallel velocity component.
Higher velocities were recorded near the bypass than at the up-stream screen.
Because of the limited access in the secondary screenwell, only one vertical velocity profile could be measured at the single secondary diversion screen. The data collected in April 1981 indicate a high level of turbulence with flow through the screen reversing direction (Table 2.0-5). Near the surface and bottom, flow passes into the screen, while at mid-depth the flow reverses and moves out through the screen.
The high surface velocity along the screen (61.2 cm/sec [2.0 ft/
sec]) exceeds the capacity of the bypass and produces a reversal of flow or countercurrent along the bottom of the screen. The irregular flow distribution was produced by the introduction of flow into the secondary screenwell from the primary jet pump at a 30 angle off the bottom of the screenwell toward the screen and bypass.
A ruptured liner in the exit port from the jet pump pipe into the secondary screenwell caused a constriction in the flow pattern that created the high velocities and resulting turbulence. This condition was identified and corrected in August 1981. The velocity measurements were repeated in April 1982. While a vertical velocity'radient was observed, the turbulence previously observed was greatly reduced (Table 2.0-6). Tempering had little effect on the velocity distribution across the secondary screen but increased water depth, created by partially closing the gate valve between the secondary and primary screenwells, reduced the velocities slightly (Table 2.0-6).
2.0-16 l.nwler, Matnskv O'ik~:lly I',ngineers
TABLE 2.0-5 VELOCITIES (cm/sec)
AT THE SECONDARY SCREEN Oswego Steam Station Unit 6 KC6NDICRY YfRlXN DEPTH (No. 5) m CHANNEL CENTER 0.5 1 -13.0 2 -61.2 2.4 + 8.2
-32.2 3.0 +12.4
+ 5.8 3.6 - 8.4
+29.6 a
See Figure 2.0-5.
b - Velocity perpendicular to the screen:
Channel 1
(+) Away from the screen (outflow)
(-) Through the screen (inflow) 2 - Velocity parallel to the screen:
(+) Away from the bypass
(-) Toward the bypass 2.0-17
TABLE 2.0-6 SECONDARY SCREENWELL VELOCITIES UNDER VARIOUS OPERATING CONDITIONS Oswego Steam Station Unit 6 DEPTH
~m CHANNEL 0 PERCENT TEMPERING IY
~s mmmmi.
GATE VA.VE 50K CLOSED; OX TEMPERING 0.3 -40.2 -38.4 -20.1
-62.8 -42.7 -39.6 0.9 -28.0 -15.2 - 9.1
-54.9 -49.4 -40.8 1.5 -17.1 - 9.1 -12.1
-60.4 -51.2 -34.7 2.1 7~3 -11.0 - 2.1
-59.1 -45.7 -29.9 2.7 + 7,9 + 7.9 + 4.3
-3203 -29.9 -17.1 Secondary screen- 4.11 4.66 4.53 well water depth (m)
See Figure 2.0-5.
b - Velocity perpendicular to the screen:
Channel 1
(+) Away from the screen (ou:flow)
(-) Through the screen (inflow) 2 - Velocity parallel to the screen:
(+) Away from the bypass
(-) Toward the bypass 2.0-18
2.2.2 Verification of Flows The second task included in the physical performance testing program consisted of evaluating the operation of the jet pumps and transport pipe relative to the initial SEW design criterion.
Based on the 1978 design calculations, the primary jet pump flow ratio is 0.83 and the secondary ratio is 0.47. In November 1979, SAW derived the orifice plate and elbow flowmeter calibration curves and made measurements through the system. True lake level was not determined for the series of measurements, and therefore the head loss associated with passage through the intake tunnel and the transport head loss from the secondary jet pump to the lake could not be calculated. It appears though th'at the tunnel head loss was less than the predicted 1.3 m (4.4 ft). ,Based pn water levels in the primary and secondary screenwells, the primary jet pump was providing a lift of only 0.38 m (1.25 ft). The flow rates, however, were near those used in the design calculationp. The remainder of the lift for the transport flow to the lake was provided by the 3
secondary jet pump; the flow rate to the lake (0.52 m /sec )17 cfs]) was slightly lower than that used in the design calculations 3
(0.54 m /sec [19 cfs]).
The observations by LMS in March 1981 were generally consistent with those made by SEW in November 1979. LMS also measured a lift between the primary and secondary screenwell of 0.38 m (1.25 ft),
although the flows measured differ. We are in agreement with S&W that the primary jet pump is running with a flow ratio near 0.9; however, the secondary jet pump is running with a flow ratio near 3
0.7. The lake transport flow (0.40 m /sec [14 cfs]) measured by LMS is well below the design value and the secondary jet pump seems to be providing most of the lift for the system.
2.0-19 l,nwlor, b,lnlsislcv tY',>kc'.Ilv I iigiocors
2.2.3 Sampl in Basin Flow Rate The final task included in the physical performance testing program consisted of evaluating the flow rate into the fish sampling basin.
Under two-pump operation, with the basin gate valve fully open and the lake discharge gate valve completely closed, the flow rate into the basin was 0.65 m /sec (23 cfs), with a basin water level of 74.98 m (246 ft). As previously mentioned, the flow rate to the lake with the sampling basin gate valve closed and the lake dis-3 charge gate valve open was 0.40 m /sec (14 cfs).
By closing down the sample basin drain valve 30K, the water level with the basin gate valve open and the lake discharge gate closed was raised to 75.26 m (246.9 ft) and the flow into the basin was 3
reduced to 0,40 m /sec (14 cfs). This operating condition pro-vides a sampling condition representative of normal plant operation.
factorilyy Our conclusion is that the overall system is functioning satis-but that under tempering conditions the turbulence in the primary screenwell most likely contributes to the observed mortality during these periods. Flow to the primary screens is reasonably uniform and the, entry velocity to both the primary and secondary bypasses is on the order of 30 cm/sec (1.0 ft/sec,). The lifts being provided by the two jet pumps are below the design conditions, however, especially in the case of the primary jet pump.
2.0-20 l.owl<:r, Mataisky 8',>k(:lly I'.ngincors
CHAPTER 3.0 DIVERSION EFFICIENCY 3.1 EXPERIHENTAt DESIGN The .biological testing program was designed with three distinct study objectives. These were to determine:
- 1. The efficiency of the angled screen
- 2. The effectiveness of the fish bypass
- 3. The viability of fish that enter the bypass system and are eventually returned to Lake Ontario The first two objectives are discussed in this chapter followed by a discussion of the viability results in Chapter 4.0. The fol lowing definitions are used throughout this report:
o The efficiency of the angled screen (primary diversion efficiency, PDE) is determined by com-paring the proportion. of fish entering the pri-mary diversion bypass with the number entering the screenwell. The difference between these numbers is the number collected on the primary traveling screens.
o The effectiveness of the fish bypass (secondary diversion efficiency, SDE) is defined as the proportion of the fish entering the secondary diversion bypass to the number entering the pri-mary diversion bypass. The difference between these numbers is the number collected on the secondary traveling screen.
e The overall effectiveness of the diversion sys-tem (total diversion efficiency, TDE) is defined as the proportion of fish entering the secondary diversion bypass to the number of fish entering the primary screenwell.
l.nwvlor, Matctskv 8'.ikc.lly I nginoors
During the two years of study, impingement on the five vertical traveling screens was monitored over a specific duration (8- or 24-hr periods). During this time, samples of the diverted fish were collected. Typically, two diversion abundance samples were col-lected over an 8-hr impinqement period and three over a 24-hr period. The samples were spaced across the impingement duration to reflect any potential diurnal periodicity.
Abundances of impinged and diverted fish were converted to number impinged or diverted per hour for comparison purposes.
The primary diversion efficiency (POE) is defined as the proportion of fish entering the primary diversion bypass in comparison to the number entering the screenwell.
The number of fish entering the screenwell (ER, the entrapment rate) is calculated as the sum of the total impingement rate (Screens 1-5) and the diversion rate:
ER IMP1 4 + IMP5 + 0 IV where:
IMP1 4 = impingement rate on Screens 1-4 (No. collected/hr)
IMP5 = impingement rate on screen 5 (No ~ collected/hr)
DIV = collection rate from the sampling basin (No. collected/hr)
The number of fish entering the primary bypass (PB , the primary bypass rate), is calculated as the sum of the impingement rate of the secondary diversion system (Screen 5) and the diversion rate:
3.0-2 I.nwlor, Matnsky 6" hknlly I'.nginoors
0 PBR = IMP5 + OIV Therefore:
PBR, IMP5 + DIV E fHP> < + INP5 + DIV The monthly PDE is calculated by summing the individual bypass rates and the entrapment rates:
Z PBR i=1 monthly n Z
i=1 where n = number of surveys conducted in the month The secondary diversion efficiency (SDE) is defined as the propor-tion of fish entering the secondary diversion bypass as compared to the number of fish entering the primary diversion bypass. The number of fish entering the primary bypass (PBR) as previously described is the primary bypass rate and the number of fish entering the secondary diversion bypass is synonymous with the diversion rate. Thus:
DIV OIV w R 5 The monthly SOE was calculated using the same procedure previo'usly described for calculating the monthly PDE.
3.0-3 I. iwlor, Matc>skv 6'.>k~.llv I'.rishi>toor8
When small numbers of fish were present in any given month, the interval was extended for two or more months. The entire two-year study period was composited for most of the species that were collected in low abundances.
3~2 SAMPLING AND ANALYSIS PROCEDURES An impingement collection period was initiated upon completion of one full wash cycle (prewash). Collection nets were then installed to sample either each of the five screens individually (April 1981-.
March 1982) or Screens 1-4 and Screen 5 separately (April 1982-March 1983) ~ The nets were checked upon completion of each. screen wash cycle to prevent debris overload; At the completion of the sample duration (8 or 24 hrs) the collection nets were removed and all organisms separated from the debris. All impinged fish were identified to species if possible, enumerated, recorded, and frozen for subsequent analysis.
Diversion abundances were determined from collections taken from the sampling basin, a 2.4 x 2.4 m (8 x 8 ft) pit in the northwest corner of the screenhouse. Routine diversion abundance collections conducted during an 8-hr impingement collection included one 30-, or 60-min sample taken during the first and last hour of the impinge-ment survey. Durinq a 24-hr survey, three 30- or 60-min collections were taken across the duration of sampling. Viability collec-tions of diverted fish were also used for diversion abundance estimates. Typically six 15- or 30-min viability collections were made concurrent with an impingement survey and sandwiched between the diversion abundance collections.
To initiate a sample basin collection, the lake discharge flow was switched into the sampling basin. Piezometer tubes were monitored to assure that the water flow into the sampling basin equaled the previous lake discharge flow. At sample termination, the gate valve 3.0-4 l.nwlor, i11;iliiskv FK P>kolly I'.nginoors
I was again switched, diverting the flow back to the lake. The basin was then slowly drained to a depth of approximately 0.3 m (1 ft).
A fish crowder was lowered along the inclined screen and moved manually across the basin floor to gently crowd the collected fish to one side of the basin for sorting purposes. All fish were classified as live (swimming normally), stunned (exhibiting some locomotion but not swimming normally), or dead (showing no signs of life), identified to species if possible, enumerated by life condi-tion (live, stunned, or dead), recorded, and frozen for subsequent analysis.
All fish collected from impingement or the sample basin during a survey and not tested for latent survival were preliminarily analyzed 'before being composited for secondary analysis. Pre-liminary analysis consisted of species identification, enumeration, tag checks, and biomass determination. No damaged or decomposing fish were included in biomass measurements or composited for second-ary analysis.
Secondary ynalysis consisted of individual length and weight mea-surements. If a composite contained more than 100 individuals per species, a random numbers table was used in the selection of a nonbiased subsample.
3.3 SAMPLING SCHEDULE The April 1981 - March 1982 sampling was conducted as the first year of the two-year program to evaluate the effectiveness'f the angled screen diversion system. It included seasonal intensive sampling and routine sampling. At the beginning of the spring, fall, and winter seasons, an intensive three-day, 24-hr/day survey was conducted to determine .the diel trends in fish distribution.
Based on these results, a routine survey was performed three times 3.0-5 I.nwlor; Pv1;ilissky 6" '.>kolly I',>spine.ors
per week in the spring, fall, and winter and once per week in the summer. The effort was reduced durinq the summer because of the low numbers of fish present. Each routine survey was 8 hrs long and was performed coincident with the diel period of highest fish abundances (as determined from the intensive survey). During each intensive and routine survey there was a specific program of impingement, diversion abundance, and survival sampling. Table 3.0-1 summarizes the scheduled sampling effort for each month. Because sampling
. concentrated on the periods of highest abundances, caution should be used when evaluating the yearly estimates of impingement abundance from these data.
The second year (Apri 1982 - March 1983) of '.he evaluation of 1
the diversion system was conducted with the first year of the required State Pollution Discharge Elimination System (SPOES) monitoring program. Surveys were performed on a variable schedule, depending upon fish abundance. SPOES impingement sampling required sixteen 24-hr impingement collections in April, twenty in May, six in August, and four in each of the remaining months. Diversion abundance was determined during each impingement survey. Table 3.0-1 summarizes the sampling schedule.
3.4 IMPINGEMENT 3.4.1 Yearl Im in ement Abundances Thirty-one species of fish were represented in the 203 impingement collections (Table 3.0-2). Dominant species were rainbow smelt and alewife, with lesser numbers of white perch, emerald shiner, gizzard shad, and spottail shiner. The estimated monthly impingement of these species is presented in Table 3.0-3. These estimates are calculated from monthly impingement rates (No./hr) based on the average impingement rate from all impingement sampling conducted within the month. As the intent of this program was to evaluate the 3.0-6 I.nwlc:r, i~1utiisky G~'kolly I'.itgiooors
0, TABLE 3.0-1 SAMPLING SCHED'jLE: APRIL 1981 - MARCH 1983 Oswego Steam Station Unit 6 DIVER%ION STUDY PERIOD REGIME IMPINGEMENT ABUNDANCE VIABILITY Apr 1901-Mar 1982 Intensive 36 continuous 18 30-min 3 surveys-b 2-hr collections collections concurrent Apr,Oct,Jan concurrent with with impinge-impingement ment a b Routine 3 8-hr collec- 1 survey per 1 survey per Spring tions per week impingement impingement Fall survey survey Winter Summer 1 8-hr collection 1 survey per 1 survey per per week impingement impingement survey survey Apr 1982-Mar 1983 Routine a b April 16 24-hr col lec- 1 survey per 3 surveys tions impinqement per week survey a b May 20 24-hr col lee- 1 survey per 3 surveys tions impingement per week survey a
June-July 4 24-hr collec- 1 survey per I survey tions impingement per week survey August 6 24-hr collec- 1 survey per 1 survey tions impingement per week survey a b September, 4 24-hr col 1 ec- 1 survey per 1 survey January- tions impingement per week March survey a b October- 4 24-hr collec- 1 survey per 3 surveys December tions impingement per week survey 2 8-hr collec-tions per week a
bA survey represents 2 or 3 30- or 60-min collections depending upon fish abundances.
A survey represents 6 15- or 30-min collections depending upon fish abundances.
3.0-7
TABLE 3.0-2 SPECIES LIST OF ORGANISHS COLLECTEO AT THE OSftEGO STEAH STATION April 1981 - Harch 1983 COHHON NAHE SCIENTIFIC NAME OIVERTEO Amer f can burbot Lota iota American eel ~uiHa XP- rostrata Alewife .osa pseuuuo aran es Black bullhead ~cta urus me as Brown bullhead ~cta urus hneuTosus Brown trout ~amo trutta Bowfin %~i a c~ava Bluegill sunfish Lepom>s macrochirus Brook silverside Walidest~es s>ccu us Brook stickleback ~uaea >econ~sans Chinook salmon Vncorhynchus ~tsha>> scha Central mudminnow ~ra > '.ll I Creek chub ~emotiTus atromaculatus Cormon shiner iiotrop>s cornutus Cnp Emerald shiner ~Notrop s ether>noides CD Fantail darter Eilie~os omaaaae are CO Freshwater drun npnnod notus runn>ens Goldfish Morass>us aura us Gizzard shad Oorosoma ceped>anum Johnny darter Et1~eos orna n>qrum Lake chub Zouesius pl~um eus Largemouth bass yi::-rooter~>; sa moides Longnose dace Logperch Lake trout Nyiin icon erc>na canto y>
Knave >nut nneaycush s caTaarac es ae Hadtom 'ylotnrus s pp Hottled sculpfn ~otus airdi X Punpkinseed Kepomi s iiiosus X Rainbow smelt Usmerus mor ax X Rainbow trout ~amo air>meri X Rock bass %Glop i es rupestrfs X Sea lamprey yet>>norton mar>nus X Smallmouth bass M>cropterus>ioaom 'eui X Stonecat i>oturus iiavus X Spottail shiner Hotropi s~usonf us X Trout-perch percopsss om>sccma us X Threespine stickleback X White bass Morone ~chr sops X White perch Horone amer>cana X White sucker Zatosto.;us commersonf X Yellow perch parce itavescens X
TABLE 3.0-3 ESTIMATED MONTHLY IMPINGEMENT Oswego Steam Station Unit 6 MONTH SMELT ALEWIfE PERCH SHAD SHINER SHINER Apr 1981 94 1,088 22 0 0 0 May 261 7,938 7 0 ,7 0 Jun 65 10,188 14 0 0 0 Jul 0 3,125 15 0 0 0 Aug 0 469 0 0 0 97 Sep 1,844 10,944 0 144 50 .44 Oct 21,003 16,093 402 558 201 74 Nov 28,303 1,073 259 187 151 7 Dec 31,300 44 7 7 104 7 Jan 1982 10,326 .379 22 156 74 89 feb 2,271 54 7 61 155 0 Mar 1,949 126 112 97 260 45 Apr 9,446 23,515 360 58 194 79 May 179 3,772 7 14 0 0 Jun 1,037 1,440 0 0 7. 0 Jul 60 3,229 0 0 0 0 Aug 469 849 394 0 15 67 Sep 1,339 4,018 43 0 36 245 Oct 424 1,429 37 0 37 156 Nov 633 151 0 21 0 0 Dec 253 30 14 0 0 0 Jan 1983 417 7 0 60 7 0 Feh 128 0 20 7 7 0 Mar 320 2,797 22 0 0 0 Total 112, 121 92, 758 1, 764 1,370 1,305 910 Based on monthly mean impingement rate (No./t r) from all impingement collections.
3.0-9
0 fish diversion system, the sampling effort was intensified during periods of heaviest fish abundance. The sampling was not conducted on a random design, and therefore the derived estimates should not be assumed to be statistically valid estimates of total impingement but rather a tool for evaluative'purposes.
Fish impingement demonstrated a definite seasonal pattern (Table 3.0-3). Spring collections were dominated by adult or subadult alewife (total length > 10.0 cm) and lesser numbers of rainbow I
smelt; fall collections were dominated by young-of-the-year (YOY) rainbow smelt, alewife, and gizzard shad (total length ( 10.0 cm).
While the same species dominated in both years, their impingement abundance differed widely (Table 3.0-4). Alewife impingement was high in the spring of 1981, while that of rainbow smelt was low. In the fall and early winter of 1981, YOY rainbow smelt predominated, with an estimated monthly impingement in December exceeding 31,000 fish. The spring and early suraner of 1982 saw smaller numbers of alewife compared to the previous spring and early summer; impinge-ment of rainbow smelt was substantially higher than during the previous spring. Lower abundances of all fish except spottail shiner and YOY smallmouth bass were seen in the fall of 1982 rela-tive to the fall of 1981.
Size distribution of the impinged alewife, rainbow smelt, and white perch followed the same general pattern during both years of the study. Most of the impinged alewife during the spring were from 15 to 20 cm in total length, while the majority of those impinged in September were less than 5.0 cm. Throughout the fall, 5- to 10-cm alewife dominated the alewife collections (Table 3.0-5). Rainbow smelt followed a similar distribution but few adults relative to YOY were impinged (Table 3.0-6). White perch adults (>20 cm) were predominant during the spring, while young from 5 to 10 cm were most often impinged during the fall (Table 3.0-7).
3.0-10 l.nwlor, ivluti>skv 6" ',>kolly I iiginoors
TABLE 3.0-4 FSTIMATED MONTHLY IMPINGEMENT BY SIZE CLASS Oswego Steam Station Unit 6 - April 1981 - March 1983 MONTH TOTAL >10 <10
~E TOTAL >10 <10 TOTAL
<<E
>13 <13 Apr 1981 94 65 29 1,088 947 141 '2 0 -
22 May 261 188 73 7,938 4,922 3,016 7 7 0 lun 65 21 44 10,188 8,864 1,324 14 14 0 Jul 0 0 0 3,125 3,094 31 15 7 8 Aug 0 0 0 469 234 235 0 0 0 Sep 1,844 74 1,770 10,944 0 10,944 0 0 0 Oct 21,003 0 21,003 16,093 161 15,932 402 0 402 Nov 28,303 283 28,020 1,073 0 1,073 259 0 259 Dec 31,300 0 31,300 44 0 44 7 0 7 Jan 1982 10;326 103 10,223 379 189 190 22 4 18 Feh 2,271 23 . 2,248 54 27 27 7 7 0 Mar 1,949 175 1,774 126 126 0 112 69 43 9,446 2,739 6,707 23,515 22,104 1,411 360 295 65 179 50 129 3.772 3,734 38 7 0 Jun 1,037 0 1,037 1,440 1,426 14 0 0 "0
,lu 1 60 0 60 3,229 3,229 0 0 0 0 Aug 469 14 455 849 611 238 394 35 359 Sep 1,339 0'1 1,339 4,018 563 3,455 43 0 43 Oct 424 373 1,429 29 1,400 37 0 37 Nov 633 32 601 151 0 151 0 0 0 Dec 253 38 215 30 15 15 14 0 14 Jan 19A3 417 259 158 7 0 7 0 0 0 Feh 17.A 115 13 0 0 0 20 0 20 Mar 370 150 170 2,797 2,797 0 22 0 22 Total 112,121 4,380 107,741 92,758 53,072 39,686 1,764 445 1,319 Based on monthly mean impingement rate (No./hr) from all impingement collections.
h Measured in centimeters.
3.0-11
TABLE 3.0-5 ALEWIFE IMPINGEMENT LENGTH FREQUENCY Oswego Steam Station Unit 6 - Apri 1981-March 1 1983 PERCENT OF TOTAL MEASURED WITHIN LENGTH INTERVAL LENGTH INTERVAL APR MAY JUN UL AUG EP OC NOV D AN 3.1- 5.0 0 0 b 0 74 17 0 0 0 5.1-10.0 13 38 13 1 26 82 100 100 0 10.1-15.0 21 17 12 12 0 2 0 0 15 15.1-20.0 65 45 73 87 0 0 0 0 85
>20.1 1 b 1 0 0 0 0 0 0 Mean 15.4 13.3 15.8 16.6 4.9 5.9 6.8 6.9 16.8 n 407 629 472 68 0 62 309 25 4 0 0 13 P RCENT F OTAL MEA URED WITHIN LENGTH INT RVAI LENGTH 98 9 3 INTERVAL APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR 3.1- 5.0 5.1-10.0 10.1-15.0 11 0
6 32 0
1 38 1,0 0 0 44 25 6
3 54 32 1
10 88 0
14 86 0
0 50 50 100 0
0 0
0 0
15.1-20.0 82 66 61 55 63 13 2 0 0 0 100
>20.1 1 2 0 1 3 0 0 0 0 0 0 Mean 16.6 16.2 15.9 15.5 13.7 6.6 6.1 6.2 8.5 9.7 - 17.2 n 328 447 105 114 71 71 41 7 2 1 0 26 a
bMeasured in centimeters.
Less than 0.55.
TABLE 3.0-6 RAINBOW SMELT IMPINGEMENT LENGTH FREQUENCY Oswego Steam Station Unit 6 - April 1981-March 1983 PERCENT OF TOTAL MEASUREO WITHIN LENGTH INTERVAL LENGTH 98 98 INTERVAL A R C NC 3.1- 5.0 3 0 0 38 10 16 17 12 9 14 5.1-10.0 28 28 67 58 89 83 83 87 90 77 10.1-15.0 64 24 0 4 b 1 0 1 1 7 15.1-20.0 6 48 33 0 b 0 0 1 1 2
>20.1 0 0 0 0 0 0 0 0 0 0 Mean 10.9 13.2 9.7 - - 5.6 6.1 5.8 5.6 6.0 5.9 6.7 n 36 25 3 0 0 24 429 571 1599 733 135 125 TAL A URE W TH N EN H N R AL LENGTH 98 9 INTERVAL APR C 0 C 3.1- 5.0 4 0 0 0 2 50 19 6 0 0 0 0 5.1-10.0 67 72 100 100 95 50 69 89 85 38 10 53 10.1-15.0 18 15 0 0 2 0 12 3 10 50 50 47 15.1-20.0 10 13 0 0 0 0 0 3 5 12 40 0
>20.1 1 0 0 0 0 0 0 0 0 0 0 0 Mean 87 90 65 73 79 60 7.0 7.0 8.2 11.5 13.4 10 '
n 321 39 35 4 41 . 28 26 36 20 24 10 15 a
bMeasured in centimeters.
Less than 0.5X.
TABLE .0-7 WHITE PERCH IMPINGEMENT LENGTH FREQUENCY Osweao Steam Station Unit 6 - April 1981-March 1983 LENGTH INTERVAL APR PER ENT F TOTAL MEA URED WI E C HIN LENG H NT RV L EC ~MA 9 3.1- 5.0 0 0 0 34 0 0 0 0 0 5.1-10.0 100 0 0 66 100 100 80 0 38 10.1-15.0 0 0 0 0 0 0 0 0 15 15.1-20.0 0 0 0 0 0 0 0 0 15
>20.1 0 100 100 0 . 0 0 20 100 31 Mean 8.1 35.0 25.8 - - - 5.6 6.8 7.8 10.4 26.5 14.7 n 18 1 1 0 0 0 44 10 1 5 1 13 HIN LENG IN ERVAL
<<J PER ENT F OTAL MEA U ED WI H LENGTH 98 983 INTERVAL A R 0 E 3.1- 5.0 0 0 32 20 0 50 0 0 5.1-10.0 18 0 59 80 100 50 100 100 10.1-15.0 14 50 0 0 0 0 0 0 15.1-20.0 4 0 3 0 0 0 0 0
>20.1 64 50 6 0 0 0 0 0 Mean 19.9 23.2 - - 7.5 5.9 7.0 5.3 - 7.6'.1 n 162 2 0. 0 34 5 4 2 0 2 3 MeasUred in centimeters.
3.4.2 Differential Impin ement by Screen Impingement, rates for each of the five vertical traveling screens were compared to identify whether differential r ~tes existed and what, if any, parameters contributi.d to the observed differences.
Table 3.0-8 provides the relative iiipingement rates for each of the five screens for five select spe~,.les: alewife, rainbow smelt, emerald shiner, spottail shiner, an~ white perch. The data for the two dominant species, alewife and r ~inbow smelt, are presented as a yearly average as well as broken drwn into three-month increments.
The smaller increments permit evaluation of the distinct age class differences between spring and fall collections of alewife and rainbow smelt. The remaining species were not impinged in high enough numbers to allow this type of analysis.
Typically, higher numbers of fish were impinged on the screens closest to the bypass (Screens 2 and 3) than by those located upstream. Screen 3 generally impi n( ed more fish than Screen 2, but ahundances vary hy species and season. Observations during screen rotation indicate that most impingeiient occurs on the third of the screen closest to the bypass. This phenomenon was also observed by Schuler ( 1973) in his experiments aad was attributed to the higher velocity that existed near the apex )f his test apparatus. Although limited access precluded making me<<surements just upstream of the bypass of the OSS-6 diversion system, velocity measurements made along other sections of the screens (Section 2.2) showed no signifi-cant nonuniform flow distributions along the face of Screens 2 or 3.
If the impingement process were related to the ability of fish to divert along a given width (distance) of screen, then impingement on the individual screens would increase as the distance diverted is 3.0-15 l,nivlor, iIIulissky K< V>kelly I'.nginoors
I TABLE 3.0-8 RELATIVE IMPINGEMENT ON EACH OF THE FIVE VERTICAL TRAVELING SCREENS Oswego Steam Station Unit. 6 - April 1981-March 1982 PUBERTY'~OTAL NP fÃCEiKVT SPECIES PERIOD SCRI.EN No. 1 2 3 4 5 Al ewi fe Tot al Ye ar 4 10 30 4 52 Apr-Jun 3 5 8. 6 79 Jul-Sep 6 19 48 3 25 Oct-Dec 5 12 44 3 36 Jan-Mar 6 23 70 0 1 Rainbow smelt Total Year 5 19 48 24 Apr-Jun 3 -9 15 6 67 Jul-Sep 4 21 62 8 5 Oct-Dec 4 16 51 5 24 Jan-Mar 8 36 32 4 21 Emerald shiner Total Year 3 38 44 5 10 Spottail shiner Total Year 3 44 18 9 26 White perch Total Year 8 16 25 4 48 a
Refer to Figure 2.0-5 3.0-16
increased. Observations of the screens during rotation and wash indicate that the distribution of fish on Screens 1 and 4 appears random, while the high percentage of fish collected on Screens 2 and 3 are on the third of the screen closest to the bypass. This suggests that the impingement process is not related solely to the swimming ability of the fish but rather is a function of its behavior. To open-water pelagic fish ( alewife and rainbow smelt),
the constriction at the bypass possibly elicits an avoidance response that reduces the potenti al for successful diversion. By attempting to maintain themselves just upstream of the constriction to the bypass, the fish are subjecting themselves to a greater potential for impingement. This would explain the observed elevated impingement rate at Screens 2 and 3.
An additional factor possibly contributing to the observed impinge-ment on Screens 2 and 3 may be the presence of several 20-cm (8-in.)
diameter pipes extending vertically along the center wall from above the water surface to the bottom of the screenwell. Their position approximately 1.5 to 2.4 m (5 to 8 ft) upstream of the bypass may produce a localized eddy in the area of the bypass that elicits an avoidance response II from some fish. Studies conducted by Schuler (1973) indicated that test specimens moved into and through the bypass only i f the flow in the bypass was free from turbulence.
Lddy currents or backwel ings significantly reduced the passage of 1
fish into the bypass channel.
The impingement rate on Screen 5 relative to Screens 1-4 differs widely by species ~ This variability is discussed in terms of.
the effectiveness of the primary and secondary diversion system in Section 3.5.1.
3.0-17
3.5 DIVERSION EFFICIENCIES 3.5.1 Primar and Secondary Diversion Efficiency 3.5.1.1 Relative Efficienc . The monthly mean entrapment rates (the sum total of the impingement and diversion rates) for 10 selected species are presented in Table 3.0-9. These rates were used to calculate the primary diversion efficiency (PDE) and the secondary diversion efficiency (SD'.) (Tables 3.0-10 and 3.0-11).
Only alewife and rainbow smelt were numerous enough for seasonal trends in diversion efficiency to be identified. The PDE data (Table 3.0-10) indicate a consisteit decrease in diversion effi-sultss. for most of the species during the two years sampled (April ciency 1981 March 1982 and April 1982 - March 1983). This trend is most clearly demonstrated in the spring alewife and rainbow smelt re-Spring of 1981 saw a major nearshore migration of adul t alewives that was reflected in a h~gh entrapment rate of predomi-nantly subadult and adult alewife f"om April through July. Little natural mortality was observed in the area, and diversion rates (Table 3.0-10) were high. The following sprinq (1982), lake water temperatures remained below normal and large numbers of alewives were observed floating dead in Osweg Harbor and along the shoreline at the time of the annual onshore alewife migration. This high natural mortality was reflected in low diversion efficiencies. The low abundances of YOY alewife in tl e fall of 1982 relative to the fall of 1981 is a further indicati(n of the poor condition of the
~
spring 1982 alewife spawning stock.
Whi l e natural mortal i ty of rainbow smel t was not observed during April of either 1981 or 1982 (month of peak entrapment of adult smelt), the same environmental stress that contributed to the alewife mortality may have contributed to the decreased diver-sion efficiency during the spring of 1982 relative to 1981.
3.0-18 I.nivlor, i%1;itusk v Ft'.","ik(.llv I'irtginoors
TABLE 3.0-9 ESTIHATEO MONTHLY ENTRAPHENT RATE Oswego Stem Station Unit 6 - April 1981 - March 1983 HONTM A' RSH EHSM GSO STSH . SHB TSB YP NOTS TOTAL Apr 1981 74. 5 12.5 0.4 1.2 1.0 0.5 0 0 0.4 0.2 94.0 Hay 118.7 4' 0.1 0 1.0 0.4 0 0 0.4 0.6 128.9 Jun 58.2 0.8 0.3 0.3 0.2 0.3 0 0 0.3 0 63.6 Jul 25.6 0.3 0 0 0.1 0.7 0.3 0.1 0 0 27.4 Aug 1.5 0 0 0 0 2.0 1.6 0 0.4 0.1 5.6 Sep . 29.9 16.6 10.0 3.0 0 0.5 0 0 0.2 1.0 62.5 Oct 112.1 104.8 8.3 19.3 8.9 5.5 0.2 0 0.5 2.2 267 '
Nov 10.4 110.1 3.6 6.6 2.6 0.7 0 2.4 0.3 1.1 141.7 Oec 2.0 164.1 1.1 1.2 0.2 0.2 0 6.3 0 0.4 178.6 Jan 1982 2.8 50.4 0.7 0.8 0.4 0.6 0.2 0.2 0.4 5.0 63.8 Feb 0.4 8.5 1.4 0.2 0.4 0 0.4 0.1 0 0.7 12.9 Har 0.4 11.6 0.9 0.4 2.5 0.2 0.2 0.2 0.2 0.4 19.4 Apr 55.3 75.0 1.1 0.2 4.3 0.8 C. 0.4 0.6 0.6 143.6 May 25.7 0.8 0.5 c 0.1 0.2 0.2 0 0.2 0.2 29.8 Jun 16.1 2.2 0.2 0 0.2 0 0 0 0.2 0.1 20.9 Jul 38.0 0.9 0.4 0 0.4 0.4 0.4 0 0.2 0.3 42.2 Aug 3;4 1.7 0.2 0 1.7 0.7 1.9 c 0.5 0.4 12.6 Sep 16.4 9.8 1.0 0.3 0.4 2.1 0.4 0 . 0 0.2 32.3 Oct 6.9 3.3 0.3 0.4 0.1 1.0 2.0 0 0 0.9 15.6 Nov 1.9 7.1 0 1.1 0.3 0.4 0.7 0 0.2 0.5 14.9 Oec 0.4 2.3 0.2 0.2 0.4 0 0 0 0 0.3 4.0 Jan 1983 0.2 2 1 0.2 0 0 c 0 c c 3.0 Feb 0 0.3 c c 0.3 0 0 0 0 c -
0.8 Mar 10.9 1.9 0.2 0.2 0.1 0 0 0 0 0.8 14.6 bNo./hr (sun total of impingement, diversion, and viability studies).
All s'pecies collected; includes small numbers of other species.
<0.1.
N - Alewife STSM - Spottail shiner RSM - Rainbow smelt SMB - Smallmouth bass ENSH - Emerald shiner TSB - Threespine stickleback GSD - Gizzard shad YP - Yellow perch KP - White perch HOTS - Mottled sculpin
TABLE 3.0-10 SECONDARY DIVERSION EFFICIENCY OF SELECTED SPECIES Oswego. Steam Station Unit 6 - April 1981 - Harch 1983 Apr 1981 99.2 99.7 93.8>> 97.3>> 93.2>> 95.9>> 92.6>> 100>> 84.5* 62.0>>
Hay 97.6 97.3>>
Jun 96.8 97.3>>
Jul 95.4 97.3>>
Aug 100 97.3>>
Sep 51.5 77.9 Oct 87.7 78.5 Nov 91.0 70.2 Dec 99.0 82.4 Jan 1982 1.8 80.3 Feb 62.5 Har 78.8 Apr 83.5>> 3* 82.7>> 75.6>> 87.1>> 83. 3>> 91. 1>> 81. 2>> 77. 5>>
Hay 81.1 83.5*
Jun 90.9 80 4*
Jul 93.0 80.4*
Aug 73.8 58.3 Sep 74.8 86.5 Oct 87.2 90.6 Nov 95.6>> 90.1 Dec 95.6* 91.2 Jan 1983 95.6 68.5*
Feb g5 6*
Har 65.9 77.2 Progl am ~
Composite Hean 83.3* 79.8* 90.3* 96.9* 91.8* 93.3* 87.0* 92.2* 84.4* 64.5>>
'mpos>te across mont s As a percent (X)
AM - Alewife STSH - Spottail shiner RSH - Rainbow smelt SHB - Smallmouth bass EMSH - Emerald shiner TSB - Threespine stickleback GSD - Gizzard shad YP - Yellow perch MP - Mhite perch HOTS - Hottled sculpin
TABLE 3.0-11 SECONOARY DIVERSION EFFICIENCY OF SELECTEO SPECIES Oswego Steaa Station Onit 6 - April 1981 - Harch 1983 Apr 1981 Hay 98.6 93.2 99.1 94.3>>
93.9'7.4'9.0 98.1>> 100 100 '83.3>> 80.3>>
Jun 78.2 94. 3>>
Jul 87.6 94.3>>
Aug 36.7 94.3*
Sep 95.4 98.4 Oct 92.1 93.1 Nov 94.1 91.6 Dec 96.4 90.2 Jan 1982 0 90.2 Feb 96.2 Har 98.2 Apr 98.6>> 99.0 95.9 95.1>> 94 .9>> 100 97 .5>> 98.6>> 92 ~ 7*
Hay 99.0 98.6*
Jun 96.3 54.5*
Jul 95.3 54.5*
AU9 90.6 95.1 Sep 88.3 88.3 Oct 82.7 91.2 Nov 92.3* 97.4 Oec 92.3>> 93.7 Jan 1983 92.3* (>oo Feb 92.3*
Har 99 ' .100 Program Composite Hean 93.0>> 93.0>> 95.9 97.4>> 98.7* 97.3* 100 99.8>> 84.0>> 82.8>>
- pos> e across mon s As a percent (X)
AW - Alewife STSH - Spottail shiner RSH - Rainbow smelt SHB - Smallmouth bass EWSH - Emerald shiner TSB - Threespine stickleback GSO - Gizzard shad YP - Yellow perch WP - White perch HOTS - Hottled sculpin
The remaining species typically exhibited lower PDEs in the second year of study, but this could be related to their peak period of occurrence and plant operating conditions. 'During the first year of study, entrapment was greatest for most of these species during October. Much less entrapment was seen during the second year, and most of this occurred during April. In October 1981, the plant did not temper the intake flow with heated discharge water, as it did the following April. Besides the thermal stress applied to the entrapped fish, tempering creates turbulence in the primary screenwell that contributes to impingement.
The low PDE values for mottled sculpin are indicative of the de-mersal habitat preferred by this species. These fish commonly sit on the screens, and are not diverted along the screen. Threespine stickleback behave similarly, but not to the extent of the sculpin.
Seasonal variation in PDE was most evident in the spring entrapment of primarily subadults and adults and the fall entrapment of young-of-the-year. As previously discussed, PDE values varied between years based on the relative condition of the fish stock entrapped; however, the subadult/adult alewife and rainbow smelt typically had higher diversion efficiencies than did the corresponding young-of-the-year.
The SDE values varied much less than the PDE values. Values charac-teristically exceeded 90K. Low SDE values (54.5X) for rainbow smelt during June and July 1982 were probably a function of the small sample size available for te: ting.
3.5 ' 2 Relative Im in ement Abundance.
~ The effectiveness of the primary and secondary system was discussed in Section 3.5. 1.1 in terms of percent diversion. Table 3.0-12 relates these data to the entrapment rate by providing the estimated monthly impingement for 3.0-22 l.nmlor, bl:<husky fa',ik(.lly I i<gine(:rs
the primary vs the secondary diversion system. Over the two-year period, an estimated 112, 121 rainbow smelt and 92,758 alewife were impinged at Unit 6, and 78 and 69K, of these, respectively, were collected on Screens 1-4. The primary diversion system accounted for 56K of the gizzard shad impingement and 85K of the emerald 3313 ~t.
shiner impingement (Table 3.0-12').
-1 1 1 collected in the primary diversion system was indistinguishable from that found for fish collected from the secondary diversion system.
1 11 Length-'frequency data for rainbow smelt, alewife, and white perch collected on Screens 1-4 and Screen 5 are presented in Tables 3.0-13 through 3.0-15, respectively. Both the adult (primarily spring) and juvenile (primarily fall) demonstrate the same distribution between screens.
3.5.2 Total Diversion Efficienc The overall effectiveness of the diversion system (total diversion ef f ic i ency, TOE) i s def ined as the rat i o of the number of f i sh entering the secondary diversion bypass (diversion rate) to the number of fish entering the primary screenwell'(entrapment rate).
Thus:
TOf
'IV DIV R 1 4 5 or TOE = POE x SOE Table 3.0-16 provides the TOE for the 10 dominant species. Alewife and rainbow smelt were abundant enough to permit ident'ification of 3 ~ 0-23 I.nwl<.r, iiv1utiisk v fi'.>kolly I',<cginoor8 I
0 1
0-
TABLE ESTIHATEO MONTHLY IHPINGEIKNT BY OIYERSIPI SYSTEM Oswego Stean Station Unit 6 - April 1981 - Harch 1983 Apr 1981 29 65 418 670 0 22 0 0 0 0 0 0 Hay 97 164 2>120 5,818 0 7 0 7 0 0 0 0 Jun 0 65 1,332 8,856 0 14 0 0 0 0 0 0 Jul 0 0 878 2,247 15 0 0 0 0 0 0 0 Aug 0 0 0 469 0 . 0 0 0 0 0 97 0 Sep 1,750 94 10,440 504 0 0 50 0 94 50 22 22 16,777 4,226 10,282 5,811 179 223 164 37 171 387 37 37 Hov 23,609 4,694 670 403 122 137 122 29 86 101 0 7 Dec 21,435 9,865 7 37 0 7 97 7 0 7 0 7 Jan 1982 7,380 2,946 372 7 7 15 52 22 149 7 67 22 Feb 2,137 134 54 0 7 0 128 27 54 7 0 0 Har 1,830 119 126 0 112 0 260 0 97 0 45 0 Apr 8,899 547 23,479 36 353 7 180 14 58 0 79 0 Hay 112 67 3,616 156 7 0 0 0 7 7 0 0 Jun 353 684 1,051 389 0 0 7 0 0 0 0 0 Jul 30 30 1,994 1,235 0 0 0 0 0 0 0 0 Aug 439 30 670 179 387 7 15 0 0 0 52 15 Sep 763 576 2,981 1,037 14 29 7 29 0 0 187 58 Oct 231 193 655 774 0 37 7 30 0 0 37 119 Rov 511 122 50 101 0 0 0 0 14 7 0 0 Oec 156 97 15 15 7 7 0 0 0 0 0 0 Jan 1983 417 0 7 0 0 0 7 0 30 30 0 0 Feb 128 0 0 0 20 0 7 0 7 0 0 0 Har 320 0 2,775 22 22 0 0 0 0 0 0 0 Total 87.403 24,718 63,992 28,766 1,252 512 1,103 202 767 603 623 287 SUH TOTAL 112,121 92,758 1,764 1,305 1,370 910 a
Based on monthly mean impingement'rate (No./hr) fran all impingement collections.
1' Primary diversion system (screen 1-4) 2' Secondary diversion system (screen 5)
AM - Alewife RSH - Rainbow smelt EHSH - Emerald shiner GSO - Gizzard shad NP - Mhite perch-
0 l
TABLE 3.0-13 LENGTH FRE UENCY OF RAINBOM SHELT IN IMPINGEHENT COLLECTIONS Oswego Stean Station Unit 6 - April 1981-Harch 1982 SCREEN LENGTH Screens 3.0- 5.0 3 0 39 7 17 21 16 9 14 1-4 5.1-10.0 27 30 57 92 82 79 81 ,89 76 10.1-15.0 67 20 4 b b 0 1 1 8 15.1-20.0 3 ~
50 0 1 0 0 1 1 3 20.1-25.0 0 0 0 0 0 0 0 0 0 I
col Hean 10.7 13.4 5.5 6.2 5.8 5.6 5.9 5.9 6.8 N 33 10 0 0 0 23 363 462 939 458 133 115 Screen 3.0- 5.0 0 0 0 0 27 13 12 4 0 10 5 5.1-10.0 33 27 67 100 71 85 88 96 100 90 10.1-15.0 33 27 0 0 2 2 0 0 0 0 15.1-20.0 33 47 33 0 0 0 0 0 0 0 20.1-25.0 0 0 0 0 0 0 0 0 0 0 12.4 13.1 9.7 6.3 5.6 6.1 5.8 6.0 5.8 5.7 3 15 3 0 1 66 109 660 275 2 10 Total length in cm.
Less than 0.5%
TABLE 3.0-14 LENGTH FRE UENCY OF ALEWIFE IN IMPINGEMENT COLLECTIONS Oswego Stean Station Unit 6 - April 1981-March 1982 L U 0 NLN SCREEN LENGTH Screen 3.1- 5.0 0 0 0 0 75 16 0 0 1-4 5.1-10.0 12 31 9 25 ~ 25 83 100 0 10.1-15.0 24 18 19 0 0 1 0 15 15.0-20.1 62 50 68 75 0 0 0 85 20.1-25.0 2 0 4 0 0 0 0 0 Mean 15.4 14.0 16.1 15.0 4.9 5.9 6.8 16.8 N 317 157 74 4 0 61 276 20 0 0 13 Scr een 3.1- 5.0 0 0 b 0 0 24 0 0 5 5.1=10.0 13 41 14 0 100 70 100 100 10.1-15.0 13 16 11 13 0 6 0 0 15.1-20.0 73 43 74 87 0 0 0 0 20.1-25.0 0 b 1 0 0 0 0 0 15.6 13.1 15.7 16.7 5,2 6.4 6.8 6.9 90 472 398 64 0 1 33 5 4 0 0 Total length in cn.
less than 0.5$
TABLE 3.0-15 LENGTH FRE UENCY OF WHITE PERCH IN IMPINGEMENT COLLECTIONS Oswego Steam Station Unit 6 - April 1981-March 1982 SCREEN LENGTH ~
Screen 3.1- 5.0 0 21 0 0 0 0 1-4 5.1-10.0 100 79 100 50 0 38 10.1-15.0 0 0 0 0 0 15 15.1-20.0 0 0 0 0 0 15
> 20 0 0 0 50 100 31 Mean 8.1 6.1 7.6 - 13.7 26.5 14.7 N 17 0 0 0 0 0 19 4 0 2 1 13 Screen 3.1- 5.0 0 0 0 44 0 0 0 5 5.1-10.0 100 0 0 56 100 100 100 10.1-15.0 0 0 0 0 0 0 0 15.1-20.0 0 0 0 0 0 0 0
> 20 0 100 100 0 0 0 0 Mean -8.5 35.0 25.8 - - - 5.3 6.4 7.8 8.2 N 1 - 1 1 0 0 0 25 6 1 3 0 - 0 Total length in cm.
0 0
TABLE 3.0-16 TOTAL DIVERSION EFFICIENCY OF SELECTED SPECIES Oswego Steam Station Unit 6 - April 1981 - Harch 1983 N AX RSH MP G 0 EH N T N YP Apr 1981 97.8 98.8 88.1* 94.8* 92.3* 94.1* 92.6* 100* 70.4* 49.8*
Hay 91.0 91.8*
Jun 75.7 91.8*
Jul 83.6 91.8*
Aug 36.7 91.8*
Sep 49.1 76.7 Oct 80.7 73.0 Nov 85.6 64.3 Dec 95.4 74.4 Jan 1982 0 72.5 Feb 60.2 Har 77.4 Apr ~ 4* 79 .3* 71.9>> 82 ~ 7* 83 .3* 88 .8* 80 .1* 71 8*
Hay 80.3 Jun 87.6 Jul 88.6 Aug 66.9 55.4 Sep 66.0 76.4 Oct 72.2 82.6 Nov 88.3* 87.7 Dec 88.3*
Jan 1983 88.3>>
Feb 88.3* 68.5*
Har 65.6 77.2 Program Hean 77.5* 74.2* 86.6* 94.4>> 90.6* 90.8* 87.0* 92.0* 70.9* 53.4*
ompos te across mon AM - Alewife STSH - Spottail shiner RSH - Rainbow smelt SHB - Smallmouth bass EMSH - Emerald shiner TSB - Threespine stickleback GSD - Gizzard shad YP - Yellow perch MP - Mhite perch HOTS - Hottled sculpin
seasonal variations in diversion efficiency while the remaining species were presented as a yearly and program average.
Alewife diversion efficiency varied widely, from zero to 97.8X, with a program mean of 77.5X. The primary variable affecting alewife diversion was the condition of the population when entrapped. The difference between the 91.0-97.8X TOE in spring of 1981 and the 40.9-80.3X TOE in spring of 1982 can be attributed to the poor condition of the alewife stock (Section 3.4.1). Typically, the alewife TOE also dropped during the post-spawn period when the adults were emaciated and in poor condition.
Rainbow smelt TOE also varied over the duration of the study. The lowest TOE (43.8X) was reported in the summer of 1982, while the highest value was in the early spring of 1981 when the pre-spawn adults were diverted at a TOE 'of 98.8X. Like the alewife, rainbow smelt diversion was related to condition of the entrapped popula-tion.
Si ze or age of the entrapped f i sh al so contributed to their abi 1 i ty to avoid impingement and divert through the system. Table 3.0-17 provides the total estimated alewife, rainbow smelt, and white perch entrapment over the two-year study period, the total number esti-mated to be diverted, and the total number estimated to be impinged, broken down by young-of-the-year and adult or subadult. These estimates are based on the average monthly impingement and diversion rates (No. /hr) and are therefore subject to certain biases in sampling (see Section 3.3.1).
The majority of the entrapped alewife (68K) were subadult or adult (total length > 10 cm) while the majority of entrapped rainbow smelt (84K) were young-of-the-year. Oiversion efficiency was greater for the larger size class of all three species reported in Table 3.0-17.
3.0-29 Lawlcr, i~latnsky K Skclly I',nginccxs
TABLE 3.0-17 ESTINTEO NINBERS FOR ALEMIFE, RAINBOM S)ELT, AND MHITEbPERCH ENTRAPPEO INPINGEO AND DIVERTEO BY SIZE CLASS Oswego Steam Station Unit 6 - April 1981 - Harch 1983 No. Entrapped 145,266 303,604 363,166 70,696 12,423 6,385 No. Impinged 39,686 53,072 107,741 4,380 1,319 445 No. Oiverted 105,580 250,532 255,425 66,316 11,104 5,940 X Effective (TOE) 73 83 70 94 89 93 Estimate based on average monthly collection rates (No./hr) over the period April 1981 through Narch 1983.
b Heasured in centimeters.
0 Totals of 83, 94, and 93K of the entrapped adult alewife, rainbow smelt, and white perch were diverted through the system. Only 73, 70, and 89K of the young-of-the-year alewife, rainbow smelt, and white perch that were entrapped avoided impingement.
The remaining eight species presented on Table 3.0-16 showed program mean TDEs ranging from 53.4X for mottled sculpin to 94.4X for gizzard shad. Except for threespine stickleback and mottled sculpin, the TDEs were lower in the second year of the program than in the first.
3.0-31 Lail er, Matnsky O'kelly 1'.ngineers
CHAPTER 4.0 SURVIVAL SUBSEQUENT TO DIVERSION 4.1 SAMPLING PROCEDURE Vi abil i ty col 1ections were made from the sampling basin located downstream of the screenwel1s and jet pumps and just prior to return offshore. Figure 2.0-5 provides a schematic of Unit 6.
The sampling basin consists of a 2.4 x 2.4 m (8 x 8 ft) pit in the northwest corner of the screenhous (Figure 2.0-3). A 76-cm (30-in.) intake pipe enters vertically through the floor of the pit (4.9 m [16 ftj) below screenhouse elevation. A 46-cm (18-in.)
discharge pipe returns the flow to the primary screenwell. A hinged counter-weighted trap door over the inflow pipe opened when flow was diverted into the basin and closed when the flow ceased. The 46-cm (18-in.) exit port was covered by a 0.3-cm (0.13-in.) mesh screen of approximately 3.0-m 2 (32-ft 2 ) surface area inclined at a 45'ngle to the wall and floor. A fish crowding deyice was used to facili-tate fish sorting and reduce handling. It is designed to slide down the drain screen and across the basin floor, maintaining a tight seal with the basin wall, and was used to qently crowd the collected fish to one side of the basin to permit identification and sorting.
A sample was initiated by switching the lake discharge flow to the sampling basin by closing the gate valve on the discharge pipe and opening the gate valve on the sampling basin entrance pipe.
Piezometer tubes on the discharqe pipe were monitored to ensure that the water flow into the smapling basin equalled the previous lake dischai ge flow. At sample termination (after 15 okr 30 min), the gate valves were switched, returning the lfow to the lake, and the basin was slowly draiined to a depth of approximately 0.3 (1 ft).
4.0-1 Lawlcr, iliatnsky K<~ Bkclly I nginccrs
The fish crowder was lowered along the inclined screen and manually slid across the basin floor. Live (swimming normally) and/or stunned (exhibiting some locomotion but not swimming normally) fish of the selected species were sorted into labeled transFer buckets full of ambient basin water and iranediately transferred to numbered latent observation tanks. Sorting was conducted under subdued light and with minimal handling to reduce shock.
If large numbers of a select species were collected, random sub-sampling of both live and stunned fish was performed to select test organisms. Test fish were transferred to either 570-liter (150-gal) or 18-liter (5-gal) containers, depending on their size and numbers.
Holding capacity of each tank was based on 5 g (0.01 lb) of fish weight per liter (1.0 qt) of water.
Test fish were segregated by life conditions (live or stunned) and by predators and prey. Initial chemistry parameters were determined for each holding tank. The fish not held for latent survival were recorded by species and life condition (live, stunned, or dead) and frozen for subsequent analysis.
Latent survival observations were conducted at 0, 12, 18, 36, -84, and 96 hrs following collection. At each observation, the holding tanks were checked for dead organisms. Any dead fish were removed, recorded, and frozen for subsequent analysis. At termination (96 hrs), all fish were sorted by life condition, recorded, bagged separately, and Frozen. At the initial and final (96-hr) observa-tions, temperature, dissolved oxygen, pH, and conductivity measure-ments in the holding tanks were recorded. At all other observations, temperature measurements were recorded.
All fish collected from the sample basin during a given survey and not tested for latent survival were identified to species, enumer-ated, and weighed. No damaged or decomposing Fish were included in 4.0-2 Lawler, b,tatusky O'kelly Engineers
biomass measurements. Individual length and weight measurements, a visual examination of sex and gonad development, and visual examina-tion for parasites was performed on selected species. All fish that were tested for latent survival received individual length and weight measurements.
4.2 SAMPLING SCHEDULE The April 1981-March 1982 sampling was the first year of the two-year program to evaluate the effectiveness of the angled screen diversion system. It included seasonal intensive sampling and routine sampling. At the beginning of the spring, fall, and winter seasons, an intensive three-day survey, including eighteen 15- or 30-min viability collections, was conducted. A routine survey was performed three times per week in the spring, fall, and winter and once per week in the summer. Each 8-hr routine survey consisted of six 15- or 30-min collections performed coincidently with the diel period of highest fish abundances (as determined from the intensive survey). Table 3.0-1 provides a summary of the scheduled sampling effort for each month.
The second year (April 1982-March 1983) of, the evaluation of the diversion system was modified slightly based on the first year results and was conducted with the first year of the required SPDES monitoring program. Surveys were performed on a variable schedule, depending upon fish abundance. Three routine viability surveys were conducted per week during April, May, 'and October through December.
One survey per week was conducted during the remaining seven months.
Table 3.0-1 summarizes the sampling schedule.
4.3 EXPERIMENTAL DESIGN One of the difficulties encountered in survival studies is the low concentration of test organisms. Many of the species enter the 4.0-3 Lawler, b iatasky O'kelly I'.ngineers
intake at rates less than one fish per hour. The volume of water and the time sampled in a survival study are limited by the need to collect the organisms at low velocity and over a short duration to minimize organism stress in the collection area. To weight all collections equally when estimating survival is not advisable since proportions based on only a few fish are extremely variable.
Therefore, where low numbers were collected, test organisms col-lected for each species (and age group) within a block were com-posited. The survival for any block or group of similar data are determined as follows:
K g No. live* in ith sample PS
= Proportion Surviving = i=1 K
g i=1 Total no. caught in ith sample where K = No. of samples in the block (month, season, or year depending upon organism density);
P (1-P )
95K CI for PS PS + 1'96 S S n
K where n = No. of test fish in the block =
g Total no. caught in ith sample 1
When only a few organisms are collected, this formula is used to calculated the precision of the survival estimate; it also defines the maximum number of fish needed for any degree of precision in the survival estimate.
When sufficient numbers of test fish were present, a block was further described by the two variables: age or size class and time interval (month, season, or year). Some species demonstrated multiple age classes that were distinctly season-specific. Adult
- "Live" refers to those alive after 96 hrs.
4.0-4 La>vier, i%1atuskv K< 8kclly lingineers
alewife, rainbow smelt, and white perch predominated in the spring while juvenile alewife, rainbow smelt, gizzard shad, white perch, and smal lmouth bass predominated in the fal . 1 Emerald shiner, spottail shiner, threespine stickleback, mottled sculpin, and johnny darter showed seasonal distribution based on numbers, but were not distinct in their size class or age distribution. In some cases a block for juvenile fish extended over a different time frame than a corresponding block for the adults of the same species.
Since viability observations were conducted on live and stunned fish and since not all fish that diverted were alive, the results of the viability observations had to be adjusted for the proportion initally classified as live, stunned, or dead. The corrected survival was determined for alewife, rainbow smelt, white perch, emerald shiner, spottai1 shiner, and gizzard shad according to the following formulae:
SUR IL IL96 + IS IS96 where SUR = the corrected survival estimate c
IL = the proportion initially classified as live IL = the percent of the initially alive 6
that survived through 96 hrs IS = the proportion initially classified as stunned IS96 the percent of the initially .
stunned that survived through 96 hrs Because of the smaller number of fish tested for the remaining species, the fish initially classified as live and stunned were combined into a single live classification. The corrected survival then was the proportion of the total initial alive (live and stunned) that survived for the 96-hr test period:
4.0-5 Lawlor, Xiiatiiskv 5" Bkvllv I',nginoors
SURV = (TL) (TL c 6 where TL = the total proportion initially classi-fied as live ( live and stunned)
TL 6
= the percent of the total alive that survived through 96 hrs 4.4 INITIAL SURVIVAL The fish present in each viability or abundance collection were initially classified as live (swimming normally), stunned (exhibit-ing some locomotion but not swimming normally), or dead (exhibiting no locomotion even upon gentle prodding). Either all or a randomly selected portion of the live and stunned fish were then transferred to the holding facility and observed for latent mortality effects.
Each life condition was maintained separately to identify differen-tial mortality for the initially live vs the initially stunned fish.
The dead fish were identified, enumerated, and saved for subsequent analysis.
Table 4.0-1 summarizes the results of the initial viability obser-vation following diversion for six species. These results include all fish collected in the sampling basin, a total of 33,834 spec-imens for these six species.
As described in Section 4.3, sample blocks (a group of samples conducted over a defined interval of time) were used to describe survival of individual species. Since length-frequency analyses were not performed in conjunction with initial classification, the blocks could not be used to segregate by age class, but since 4.0-6 Lnwlcr, Matnskv 6'kclly 1'.ngineers
TABLE 4.0-1 (Pag )
INITIAL VIABILITYCLASSIFICATION AS LIVE OR DEAD FOLLOMING DIVERSION Oswego Steam Station Unit 6 - 1981-1983 0~ 0~ No.
HONTH OBS LIVE STUNNEO DEAD OBS LIVE STUNNEO DEAD OBS LIVE STUNNEO DEAD Apr 1981 47 5 55.6 22.3 22.1 Hay 527 14.4 48.2 37.4 36 41.7 30.6 27.8 Jun 1166 33.2 28.5 38.3 Jul 301 55.8 14.3 Aug 171 12.3 2.3 85.4 0 Sep 95 31.6 0 68.4 Oct 5,204 63.1 7.4 29.5 3,517 61.0 4.6 34.4 Nov 246 59.3 15.4 25.2 2,017 40.5 11.7 47.8 Dec 70 42.9 37.1 20.0 5,849 31.3 18.8 50.0 Jan 1982 2,541 38.1 23.5 38.3 Feb 270 16.3 47.4 36.3 Har 443 49.0 10.8 40.2 Apr 1,033 77.5 18.3 4.2 2,674 71.8 8.9 19.3 Hay 1,517 42.6 45.3 12,1 96 40.6 12.5 46.9 Jun 418 29.7 55.7 Jul 1,086 41.5 40.5 Aug 79 53.2 17.7 Sep 392 45.4 8.2 46.4 180 20.6 5.0 74.4 Oct 151 19.2 17.9 62.9 81 24.7 3.7 71.6 Nov 84 73.8 9.5 16.7 286 32.9 13.6 53.5 Oec 51 52.9 33.3 13.7 79 62.0 7.6 30.4 Jan 1983 51 21.6 13.7 64.7 Feb Har o separate y n t a i e c assi cat on.
) Combined across months during periods of low abundance.
TABLE 4.0-1 (Page 2 of 2)
INITIAL VIABILITYCLASSIFICATION AS LIVE OR DEAD FOLLOWING DIVERSION Oswego Steam Station Unit 6 - 1981-1983
- o. No.
HONTH OBS LIVE STUNNEO DEAD OBS LIVE STUNNEO DEAD OBS LIVE STUNNEO DEAD Apr 1981 Hay 0 0 0 Jun 0 289 92.7 21 52 0 Jul 0 0 Aug 0 0 T Sep 83 92.8 0 7.2 22 63.6 13.6 22.7 Oct 425 94. 1 3. 3 2.6 1,043 80.9 9.6 9.5 Nov 106 86.8 6.6 6.6 7 86.0 5.3 8.8 188 59.6 27.7 12.8 Oec 51 74.5 17.6 7.8 54 33.3 51.9 14.8 Jan 1982 35 71.4 17.1 11.4 41 4.9 87.8 7.3 Feb 41 87.8 9.8 2,4 Har 20 65.0 20.0 15.0 Apr 26 73.1 19.2 7.7 0 Hay 25 40.0 8.0 52.0 0 Jun 0 Jul 21 71.4 9.5 19.0 0 Aug 0 Sep JO 55.0 5.0 40.0 45 82.2 6.7 11.1 Oct 36 77.8 0 22.2 Nov Dec Jan 1983 0 Feb 0 Har 0 o separa e y n a e c ass ca on.
f Combined across months during periods of low abundance.
seasonal trends were predominantly composed of single age groups, i.e., young-of-the-year (YOY) in the fall and adults in the spring, the blocks typical.ly represent single age groups of fish.
As demonstrated by the data, a significant proportion of some species were dead at initial sorting and classification. During August 1981, 85K of the diverted alewives were dead at collection while during April 1982 only 4X were collected dead . The ranges for rainbow smelt, gizzard shad, and white perch were 19 to 74K, 7 to 23K, and 2 to 57K, respectively. In each case, the periods of highest initial mortality were associated with entrapment of YOY while the periods of lowest initial mortality were associated with entrapment of adults of the species. Control tests run in July 1982 on alewife (one of the most sensitive species) placed directly into the sampling basin during a collection indicated an initial mor-tality associated with the collection process of less than 4X (4 initially dead out of .110 test fish). Thus, the initial mortalities observed in the collection basin were most likely a manifestation of stresses that occurred before the fish reached the sampling basin rather than from stresses occurring during the collection process.
4.5 LONG-TERM SURVIVAL Long-term survival observations (96-hr) were conducted on 7905 fish representing 34 species (Table 4.0-2). Ten of these species were represented by more than 40 specimens. Two species, alewife and rainbow smelt, were represented by enough individuals to describe their survival by age class and season, while white perch were described by age class (Table 4.0-3). When corrected for initial mortality (Section 4.3), the trends remained essentially the same but the final survivals seen through the system decreased (Table 4.0-4).
.4.0-8 I.aivlcr, iWIatxisk v K< Piki.lly I'.nginoors
TABLE 4.0-2 VIABILITYTESTING Oswego Steam Station Unit 6 - April 1981 March 1983 TOTAL SPECIES SCIENTIFIC NAME TESTED Alewi fe Rainbow smelt
~h Osmerus mordax 3599 2846 Emerald shiner Notrop>s aataerinoides 367 Gizzard shad 249 White perch Morone americana 229 Mottled sculpin Lottus ~a>r > 125 Spottai shiner 1 Notre iseeu sonius 119 Smallmouth bass >cropterusuuo om>eui 69 Threespine stickleback 63 Yellow perch 43 Rock bass 34 Logperch 31 Johnny darter EEtEeostoma n> rum 23 Bluegill sunfish 16 Trout-perch percopsis om>scomaycus 13 Brown trout ~amo trutta 12 American burbot Lota iota 11 White bass Moroneec ir sops 8 Rainbow trout Yaamo air ner> 8 Pumpkinseed Lepomis i osus 6 Longnose dace fKin~c t s cataractae 6 White sucker atostomus commersoni 4 Stonecat 4 Common shiner Notrop>s cornutus 4 Lake trout Salvelinus ~nama cusb 3 Central mudminnow 2 Lake chub I
~ouesius plumbeus 2 Brown bullhead ~cta urusnennuosus 2 American eel ~n ui a rostrata 2 Largemouth bass acro ter~us sa moides 1 Chinook salmon Oncorh nc us tshawytscha 1 Goldf i sh arassius auratus 1 Black bullhead ~cta urus ~me as 1 Sea lamprey 1 Total 7905 Includes initially stunned and initially live specimens.
4.0-9
TABLE 4.0- 1 of 3)
ALEWIFE, RAINBO'W SMELT, A[0 WHITE PERCH LONG-TERM 96-hr SURVIVAL BY SIZE CLASS Oswego Steam Station Unit 6 - 1981-1983 I. Alewife MONTH o. o. oo 0~
Apr 1981 69 21.7 NT 805 36.9 NT May 201 7.5 17 525 12.6 14 0 Jun 160 28.8 142 0.7 Jul NT NT 80 55.0 17 0 Aug NT NT Sep 339 30.7 56 3.6 81 85.2 10 30.0 Oct Kov 65 49.2 11 18.2 Oec Jan 1982 NT NT NT NT Feb NT NT NT NT Mar NT NT 116 19.0 4 0 Apr 9 1 0 Hay 102 15.7 70 1.4 Jun NT NT 84 11.9 121 0 Jul NT NT Aug 65 3.1 9 Sep NT NT Oct 7 85.7 4 0 Nov Oec Jan 1983 NT NT NT NT Feb NT '
NT NT NT Mar NT NT NT NT a
Percent alive at 96-hr observation.
NT Not tested.
TABLE 4.0-3 (Page 2 of 3)
ALEWIFE, RAINBOW SHELT, A50 WHITE PERCH LONG-TERH 96-hr SURVIVAL BY SIZE CLASS Oswego Stean Station Unit 6 - 1981-1983 II. Rainbow Smelt HONTH o. o. No. Ho. U V Apr 1981 42 33.3 MT 199 90.4 HT Hay NT 25 0 NT Jun NT NT NT Jul HT HT NT MT Aug NT NT NT NT Sep 175 50. 3 38 36.8 NT NT Oct 64 70.3 13 30.8 Hov 157 35.0 23 34.8 Oec 580 12 ' 141 14.9 Jan 1982 301 14.0 179 2.2 170 100 1 100 Feb 2 11.9 29 6.9 Mar Apr 272 97.8 1 0 Hay NT HT Jun Jul NT NT NT NT NT i
NT Aug NT NT NT NT Sep 83 38.6 7 0 NT NT Oct 3 100 1 0 Hov NT NT Oec NT Jan 1983 T NT NT NT Feb NT NT NT NT Har NT NT NT NT Percent alive at 96-hr observation NT Not tested.
0 TABLE 4.0-3 (Page 3 of 3)
ALEWIFE> RAINBOW SMELT, A$D WHITE PERCH LONG-TERN 96-hr SURVIVAL BY SIZE CLASS Oswego Stean Station Unit 6 - 1981-1983 III. White Perch HONTH 0~ o. o.
Apr 1981 38 71.1 9 55.6 152 84.2 May Jun Jul Aug Sep Oct Nov Dec Jan 1982 Feb Har Apr Hay Jun Jul Aug Sep Oct Nov Dec Jan 1983 Feb Har a
Percent alive at 96-hr observation
TABLE 4.0-4
. ALEWIFE, RAINBOW SMELT, AND WHITE PERCH SURVIVAL CORRECTED FOR INITIAL MORTALITY Oswego Steam Station Unit 6 1981-1983 MONTH Apr 1981 13.6 23.1 24.1 65.4 51.9 64.9 May. 1.1 1.8 24.1 0 Jun 2.5 9.8 24.1 NT Jul NT 30.7 NT NT Aug NT 6.8 NT NT Sep 3.9 11.2 15.9 NT Oct 19.6 56.0 32.4 44.3 Nov 18.8 32.0 18.2 32.1 Dec 14.5 27.9 6.7 27.8 Jan 1982 NT NT 5.8 61.6 Feh NT NT 5.2 63.7 Mar NT 8.2 6.5 59.8 Apr 0 14.7 9.2 70.2 May 0 7.3 NT 39.7 Jun NT 3.5 NT 39.7 Jul NT 4.9 NT NT Aug 1.6 6.3 NT NT Sep 1'. 4 NT 8.0 NT Oct 0.6 16. 4 9.5 24.7 Nov 2.3 63.2 12.7 NT Dec 1.6 NT 23.9 NT Jan 1983 NT NT NT NT Feh NT NT NT NT Mar NT NT NT NT N - None tested or atent surviva o servat>ons.
Percent surviving 96 hr (Section 4.3).
4.0-11
1 Al ewi fe surv i v al results varied widely throughout the year and across the two years of study. The two maximum periods of alewife entrapment at OSS-6 are the early spring-summer period when subadult and adult alewives (>10 cm) predominate and'he fall period when the YOY (<10 cm) alewives predominate. Survival of adult alewife following diversion typically exceeded that of YOY alewife.
During the first year of the study, adult alewife survival ranged from 2 to 56K, with the peak spring period ranging from 2 to
~
23K (Table 4.0-4). Survival during the second year ranged from 4 to 63K, with the peak spring period ranging from 7 to 15K.
At the beginning of their onshore migration (March-April), adult alewife survival through the system was as high as 23K, and dropped to 2-10K during their normal spawning period (May-June). This period was characterized by an increase in water temperature and an increase in the number of emaciated adult alewives collected.
g <<g 1 i<<
Most of the specimens collected during this period had varying i (~S1 i .i. Il survival observed in July 1981 is most likely reflective of the post-spawn recovery that continues through early fall when the adults move offshore and the YOY predominate.
The low survival results reported during the spring and early summer of 1982 were coincident with a major alewife die-off observed in the vicinity (see Section 3.4). As the population recovered either from the stresses of spawning or environmental conditions (tempera-ture, low iodine levels, etc.) contributing to their observed die-off, adult alewife survival increased. Only a few adults were collected in the fall, but a survival of 56K was observed in October 1981 and 63K in November 1982. The reduction in survival in Novem-ber and December 1981 could be related to the decreased water temperatures with the onset of winter and/or the effect of tempering that was also initiated during this period.
4.0-12 Laivlor, iXlatnsky E~'kolly 1'.nginoors
YOY alewife demonstrated similar seasonal responses. YOY alewife were first observed in the cooling water system in late August when the organisms were 2.5 to 3.5 cm in total length. By October the young had grown to 5.0 to 6.5 cm in total length. Survival during October 1981, when most of the entrapment occurred, was 20K.
Survival for the yearlings (8.0-9.0 cm) through May and June (1981) was lower than that reported for YOY in the fall. This pattern agrees with the adult survival and suggests that the late spring mortality commonly observed in alewife populations under natural conditions is not related solely to stresses associated with spawning. Numerous causes for the periodic midwinter, early spring, and summer massive mortalities of alewives have been hypothesized.
They range from failure to adjust to temperature extremes and fluctuations on the Great Lakes, exhaustion of the food supply, failure to osmoregulate, failure to extract sufficient iodine from the iodine-poor Great Lakes, or a combination of one or more of these causes (Brown 1968).
Rainbow smelt survival also varied dramatically by age class and season. Adult (>10 cm) rainbow smelt survival subsequent to diver-sion was closely related to their spawning condition. Throughout the late winter and early spring, rainbow smelt survival ranged between 60 to 70K. By completion of spawning in May, their survival had dropped. Only a few specimens were collected during the summer, and these were typically emaciated and infected with fungus.
Numbers of adults remained low throughout the fall, but those collected were in better condition.
YOY (<10 cm) rainbow smelt survival during the fall was higher than the corresponding alewife YOY survival. Survivals decreased-during December and remained low throughout the winter (January-March). The increased survival observed for the smelt yearlings for the spring-summer period ( 1981) relative to that observed during the winter period ( 1982) was expected because of the moderating water 4.0-13 Lawlcr, hlatnskv O'kelly 1'.ngincers
.temperatures, the termination of tempering, and an increase in planktonic food. It was, however, in contrast to the observed trend for yearling alewife.
White perch were not collected in sufficient abundance to permit breakdown by year, but a difference in survival subsequent to diversion was evident between YOY and adult white perch. YOY white perch (<13 cm) were primarily collected during October 1981 and showed a survival of 52K, while adult white perch (>13 cm) were primarily collected during April 1982 and showed a significantly higher survival of 65K (Table 4.0-4).
The remaining species were either tested in insufficient numbers to enable similar breakdown (gizzard shad, threespine stickleback) or survival across all conditions was so high that further breakdown was unwarranted (emerald shiner, spottai 1 shiner, smallmouth bass, and yellow perch). Table 4.0-5 provides a summary of these spe-cies. Of the 31 species, only four, gizzard shad, trout-perch, threespine stickleback, and central mudminnow, demonstrated a survival of less than 75K. Two of these species, trout-perch and central mudminnow, were tested in insufficient numbers to evaluate their survival results. Since gizzard shad and threespine stickle-back are considered fragile species, the results are not surprising.
Overall, survival of fish specimens following passage through the diversion system is highly species-, age-, and season-specific.
Species can be classified as hardy, intermediate, or fragile based on their ability to survive the stresses associated with passage through the diversion system. In some cases, survival of individual species may vary widely, depending upon age, i.e., YOY vs adult rainbow smelt, or upon season, i.e., early spring vs late spring rainbow smelt. Typically, adult survival was higher than survival of the YOY of the same species. Adult survival was highest immedi-ately preceding the spawning activity and lowest immediately follow-ing.
4.0-14 I.nwlcr, Matnskv 8'kclly I',nginccrs
TABLE 4.0-5 SURVIVAL SUBSEQUENT TO PASSAGE THROUGH THE DIVERSION SYSTEM Oswego Steam Station Unit 6 - April 1981 - March 1983 LONG-TERN VIABILITYRESULTS No ~ No. ALIVE INITIAL SYSTEM TAXON TESTED AT 96 hr SURVIVING SURVIVAL SURVIVAL American burbot 11 11 100 100 100 American eel 2 2 100 100 100 Black bullhead 1 1 100 100 100 Brown bullhead 2 2 100 100 100 Brown trout 12 12 100 100 100 Bluegill sunfish 16 16 100 87.5 87.5 Chinook salmon 1 1 100 100 100 Central mudminnow 2 1 50.0 100 50.0 Common shiner 4 4 100 100 100 Emerald shiner 367, 341 92. 8 93.5 86.8 Gizzard shad 249 152 61.0 '0.0 54.9 Goldfish 1 1 100 100 100 Johnny darter 23 22 95.6 94.7 90.5 Lake chub 2 2 100 100 100 Largemouth bass 1 1 100 100 100 Longnose dace 6 6 100 100 100 Logperch 31 31 100 100 100 Lake trout 3 3 100 100 100 Mottled sculpin 125 117 93.6 81.5 76.3 Pumpkinseed 6 5 83.3 100 83.3 Rock bass 34 32 94.1 94 ' 89.3 Rainbow trout 8 7 87.5 100 87 '
Sea lamprey 1 1 100 100 100 Seal lmouth bass 69 64 92.8 95.1 88.2 Spottail shiner 119 108 90.8 89.4 81.2 Stonecat 4 3 75.0 100 75.0 T~reespine stickleback 63 9 14.3 65.4 9.4 Trout-perch 13 11 84.6 83.9 71.0 W~ite bass 8 6 75.0 100 75.0 W~ite sucker 4 3 75.0 100 75.0 Yellow perch 43 42 97.7 100 97.7 a .
ive and stunned fish combined because of the low numbers of fish in one or both categories.
4.0-15
4.6 OFFSHORE SURVIVAL 4.6.1 Samplinq Procedure A specially designed net consisting of an attachment cone and holding car was constructed and deployed offshore to collect the fish as they were discharged from the diversion return conduit. The net consisted of a 5.2 m (17 ft) long, 1.8 m (6 ft) diameter, modi-fied hoop net that attached by drawstring over the flange on the discharge conduit (Figure 4.0-1). When in the collection mode, the net was oriented horizontally with its apex (attachment cone) attached to the discharge port and the base (holding car) anchored approximately 6.1 m (20 ft) away. The densely woven base produced a stagnant area where fish could reside during the collection period.
Small buoys attached directly to the fiberglass support rings and anchor lines attached to the base of the net were used to maintain its shape and orientation along the axis of discharge flow.
The net was set and retrieved by scuba divers. A 6-8 m (20-25 ft) boat, modified with a boom and gunwale struts designed to hold the net vertically at the water surface, was used as the crew boat. At the designated sample end time, the attachment cone was removed from the discharge port, tied shut, and the net rotated from its hori-zontal orientation to a vertical orientation with the apex end being taken to the crew boat. The net was then raised slowly to enable initial observation of the number of fish and their general condition. Initially dead fish were removed and bagged for later analysis. No effort was made to separate initially stunned from initially live fish (Section 4.1).
The holding car. was then separated from the attachment cone and attached to a flotation platform that allowed in situ holding for between 48 and 96 hrs depending upon weather conditions. Vi-ability observations and removal of dead fish were conducted every 4.0-16 Lnwlor, b,1atiiskv O'kolly I',rtginoers
FIGURE 4.0-1 LAK E COLLECTION AND HOLDING NETS FLOATS 0'llZP SUitFACE
\
I WEIGHTS I
)I"KOOP5 I
G 0.6 CIII NKOM I I
i 5t:I'I PERKS AOLC L KIOOP5 COl.t, AR ORJL'l
~
FLOAT POPE ANCHOR SA K 0 AKCKOII
'i v g /4 HOLDING AND COLLECTION MODE OBSE RVATION MODE
24 hrs. Fish were classified as either initially dead, dead at one of the observations, or alive-at-termination.
4.6.2 Samplin Schedule Lake discharge collections, were collected during April, May, June, September, October, and November 1982 coincident with the periods of highest entrapment. Ouring each sampling month 48 to 120 hrs of sampling was conducted depending upon the numbers of fish and weather conditions. During periods of high abundance, the net was deployed for 1- or 2-hr durations; during the periods of lower abundance, the net was deployed for a 24-hr duration.
4,6.3 Survival Results A total of 10,699 fish representinq 23 species were collected in the offshore sampling effort (Table 4.0-6). The majority (81/) of those were alewife, collected during the three-month period from April through June 1982. The majority of these fish were classified as dead-on-collection. As discussed in earlier sections of this report (Section 3.4 and 4.4), this period was characterized by a massive die-off of subadult and adult alewife in the site vicinity.
Offshore survival of alewife during this period was below 1X (Table 4.0-6) as compared to 4 to 15K survival based on collections from the sampl ing basin (Table 4.0-4) . Both the offshore and pl ant collections were dominated by subadult and adult alewives (>10 cm).
Offshore alewife survival in the late fall increased to 7X while concurrent in-plant sampling provided a 63K survival for adult alewives (Table 4.0-4).
Rainbow smelt survival, based on April 1982 offshore sampling, was 85$ as compared to 70K based on in-plant sampl ing. The 8 to 13K 4.0-18 Lawlcr, iXlatnsky O'kelly 1'.ngineers
0 0
TABLE 4.0-6 SURVIVAL RESULTS OF FISH COLLECTED AT THE OFFSHORE DISCHARGE Oswego Stean Station Unit 6 - April 1981-Harch 1983 JUN SEP OCT NOV GRANO TOTAL SPECIES TESTEO 9 TERH. TESTEO 8 TERH. TESTEO 0 TERN. TESTEO 8 TERN. TESTEO 8 TERN. TESTEO ja TERN. TESTEO 8 TERN.
AM 343 0 5,587 1.0 2,785 1.0 44 2.0 511 1.0 44 6.8 9,314 1.0 RSM 33 84.8 137 3.6 322 1.0 3 0 42 0 39 0 576 6.1 EHSH 3 66.7 1 0 97 40.2 6 16.7 107 40.2 HOTS 7 0 25 68.0 7 71.4 5 0 36 77.8 27 92.6 107 70.1 RB 1 100 87 98.8 4 50.0 13 92.3 1 100 106 96.2 YP 5 100 17 76.5 57 73.7 13 53.8 92 72.8 JD 24 79.2 63 84.1 87 82.8 GSO 11 9.1 65 26.2 76 23.7 STSH 100 3 33.3 8 75.0 4 75.0 37 89.2 2 50.0 60 83.3 SHB 100 1 100 13 84.6 34 82.4 8 87.5 58 84.5 TPER 50.0 13 69.2 16 87.5 31 77.4 MP 37.5 3 66.7 9 55.6 4 0 25 40.0 AE 100 9 100 4 100 5 100 100 20 100 BSF 4 75.0 10 60.0 14 64.3 PS 11 90.9 100 12 91.7 BNB 1 100 3 66.7 4 75.0 ABUR ICO 100 1 100 3 . 100 CHIN 2 100 2 100 BNT 100 1 100 CSH 0 1 0 LHB 100 1 100 LP 100 1 100 KS 100 1 100 Includes initial dead.
- None tested.
0 reported for YOY survival in-plant during the fall sampling (Septem-ber-November) was not reflected in the offshore survival results.
No survival was reported for the 84 rainbow smelt (predominantly YOY) collected offshore in the fall of 1982.
At 40K, white perch survival (predominantly adult), based on off-shore sampling, was substantially lower than the 651 based on in-plant sampling. Insufficient numbers of YOY white perch were collected offshore to enable any type of comparison.
Of the seven remaining species represented by at least 20 organisms from in-plant and offshore sampling, three (spottai 1 shiner, small-mouth bass, and Mottled sculpin) demonstrated similar survival at both locations; three (yellow perch, emerald shiner, and gizzard shad) had higher survival in-plant than offshore; and one (rock bass) demonstrated higher survival offshore than in-plant. Observa-tion of both in-plant and offshore collection procedures suggests that the offshore procedures place a slightly higher stress on the test organism than do the in-plant procedures. Also, predator and prey were not always able to be separated and some mortality was undoubtedly the results of predation. For the hardier species, such as the salmonids, smallmouth bass, and rock bass, the added stress had a minimal effect on the final data. However, the more fragile species such as alewife, gizzard shad, and YOY rainbow smelt did exhibit lower survivals based on the offshore collection.
The incremental increases in stress applied to the organism as it passes through the diversion system will have a cumulative effect until the organism either returns to the lake or succumbs. The transport offshore through the discharge conduit is the last stress applied before the organism is released to the source water body.
This additional stress appears to have minimal effect on the hardy sport fish: smallmouth bass, salmonids, and rock bass.
4.0-20 La~vier, Matusky &'kellyI',ngineers
0)
~
These species are capable of passing through the entire diversio'n system, including the discharge conduit, with survivals in excess of 80K. For the more fragile forage species, namely, alewife, gizzard shad, and YOY rainbow smelt, the additional stress associated with F
the offshore transport appears to have reduced their survivals slightly. Based on the low in-plant survivals, however, the ob-served reduction is not surprising.
In general, the survival results obtained in-plant provide a good indication of the ultimate survival to be observed offshore. While some additional mortality can be expected to result from the off-shore transport, the magnitude of this mortality will vary by species and age or size.
4.7 DARK-INDUCED DIVERSION 4.7.1, Methods and Materi al s In preliminary studies performed during 1981, it was observed that a sudden reduction of ambient light level in the screenwell to virtual darkness produced a rapid increase in the number of diverted fish. The actual mechanics of the phenomenon are unknown, but it is most likely related to a disorientation in the fish caused by a physiological change from photopic vision (daylight vision that primarily uses the cones of the retina) to scotopic vision (night vision that primarily uses the rods). With this disorientation, it is believed that the fish are displaced downstream in the current and into the bypass. Momentary contact with the screen may occur but increased impingement was not observed concomitant with the increased diversion.
Based on these preliminary observations, a 13-month study was con-ducted from March 1982 to March 1983. Light entered the screenwell 4.0-21 Lawlcr, Matnsky O'kolly I'.nginoors
0 primarily through the steel access grating that made up a con-siderable portion of the screenhouse floor. Since the screenhouse was under constant i lumination, the screenwel 1 1 below was also constantly illuminated. In order to control the light level within
'the screenwell, four 100-watt incandescent lights were positioned under the grating; one each on the east and west side of the screen-well just upstream of the bypass and one each on the east and west side of the screenwell just upstream of the bar racks. 'ach light was controlled by a rheostat and could be turned off simultaneously.
To eliminate background light entering through the grating, heavy gauge black plastic was laid over all the grating and covered by sheets of plywood. Black plastic was also wrapped around the screen housings and any location through which light might penetrate to the screenwell. Thus, the screenwell light condition was controlled solely by the four lamps.
The experimental design required a weekly collection of fish induced to divert by darkening the screenwell (turning off the four lights).
This collection immediately followed the regular diversion abundance and survival collections and thereby enabled comparison of fish survival subsequent to diversion under both normal light conditions and the experimental or "dark-induced" diversion. Sampling was conduct'ed throughout the day to avoid possible diel behavioral cycles that may affect diversion or survival following diversion.
Impingement was monitored throughout the period to identify any effects resulting from the dark cycle.
A dark collection was\ of 15- or 30-min duration depending upon the numbers of fish present. The same procedures were followed for the dark viability collections as were previously outlined for the standard (light) collections (Section 4.1). As soon as flow into the sampling basin was stabilized, the light in the screenwell was turned off and remained off until this sample was complete. Once 4.0-22 I.awlor, Matnsky K~ Sl<ollv I'.nginoors
0 0
the bypass flow was returned of fshore and the basin was closed, the lights were turned on and remained on until the next dark collection (typical ly, one week).
t 4.7.2 Results A total of 54 collections were conducted simultaneously with the screenwell darkening. Typically, the diversion rate (number of fish collected/hr) measured during the dark collection was 5 to 10 times greater than the diversion rate measured during the preceding light collections. This was most evident during periods when alewife or rainbow smelt were abundant.
Table 4.0-7 provides the survival results for alewife and rainbow smelt subsequent to dark-induced diversion. Adult alewife survival in the spring (Narch-Hay) of 1982 under light conditions ranged from 7.3 to 14.7X, while under dark conditions the range was 27.4 to 48.7$ (Table 4.0-7). Likewise, YOY alewife dark-induced survival during late summer-fall ranged from 0 to 40.5X as compared to the 0.6 to 2.3X range observed under light conditions. Survival of adult alewives following dark-induced diversion during this period was also higher than the corresponding diversion under light condi-t lons.
Rainbow smelt survival following dark-induced diversion reflected the same improvement in survival as observed for alewife.
Table 4.0-8 provides the results of the remaining seven species that, were represented by a minimum of 20 test organisms. In each case, survival following dark-induced diversion was higher'han under the 1
light conditions. The more hardy the species or the higher the survival under light conditions, the less the obser'ved improvement.
The fragile species, alewife, gizzard shad, and juvenile rainbow 4.0-23 La>glor, Matcssl<v O'kolly I'.nginoors
TABL ALE14IFE AND RAINBOW SMELT SURVIVAL SUBSEQUENT TO DARK-INDUCED PASSAGE THROUGH THE DIVERSION SYSTEH Oswego Steam Station Unit 6 cm
'x INITIAL SYSTEH SYSTEM x INITIAL SYSTEH SYSTEM b
b MONTH No. SURVIVAL SURVIVAL SURVIVAL SURVIVAL No. SURVIVAL SURVIVAL. SURVIVAL SURVIVAL ALEWIFE Mar 1982 0 0 Apr 0 155 27.7 98.8 27.4 14.7 Hay 1 0 76 48.7 100 48.7 7.3 Jun I NT 118 31.4 95.9 30.1 3.5 Jul 1 NT 372 28.0 98.6 27.6 4.9 Aug 39 40.5 100 40.5 1.6 179 36.3 100 36.3 6.3 Sep 52 0 89.7 0 1.4 62 17.7 89.7 15.9 NT Oct 340 8.3 97.1 8.1 0.6 179 48.4 97.1 47.0 16.4 Nov Oec Jan 1983 j 2.3 1.6 j 63.2 NT Feb Har RAINBOM SMELT 59.8 Har 1982 Apr May
, 0 0
0 23 0
j 92.9 92.9 70.2 Jun 0 0 Jul 0 0 Aug 74 12.2 96.7 11.8 NT 1 NT Sep 53 58.5 84.8 49.6 8.0 1 NT Oct 1 9.5 50 67,8 96.2 65.2 24.7 Nov 8 12.7 5 NT Dec 18 42.9 57.9 24.8 23.8 0 NT Jan 1983 I NT 1 NT Feb 0 1 NT Mar 0 0 Corrected for initial mortality.
+Composited over interval due to low abundance.
Taken from Table 4.0-4.
NT - None tested
TABLE 4.0-8 SURVIVAL SUBSEQUENT TO "DARK-INDUCED" PASSAGE THROUGH THE DIVERSION SYSTEM Oswego Steam Station Unit 6 LONG-TERN VIABILITYRE ULTS DARK LIGHT No. No. ALIVE INITIAL SYSTEM SYSTEM b
SPECIES TESTED 8 96 hr SURVIVING SURVIVAL SURVIVAL SURVIVAL Spottail shiner 439 396 90.2 99.2 89.5 81.2 Emerald shiner 63 57 90.5 100 90.5 86.8 Trout-perch 44 37 84.1 97.8 82.2 71.0 Johnny darter 39 37 94.9 100 94.9 =
90.5 Gizzard shad 32 28 87. 5 100 87.5 54.9 Rock bass 29 29 100 100 100 89. 3 Mottled sculpin 23 23 100 - 96.0 96.0 76.3 a
Corrected for initial mortality.
b Taken from Table 4.0-5.
smelt, showed the most marked increase in survival as a result of dark-induced diversion.
The most obvious effect of the dark diversion is the significant reduction in initial mortality at collection. In general, the fish in the sampling basin during the initial classification (see Section 4.1) appeared much more lively and fewer stunned and dead fish were recovered following a dark-induced diversion than during the previ-ous regular collections. Initial alewife survivals for dark-induced diversion ranged from 89.7 to lOOX (Table 4.0-7) while the initial survivals for the corresponding regular diversion ranged from 37 to 96K (Table 4.0-1). Rainbow smelt ranges were 57.9 to 96.5X (Table 4.0-7) and 26 to 81K (Table 4.0-1) respectively for dark-induced and regular light diversion.
The increased survival observed subsequent to dark-induced diversion relative to that observed under continuous light conditions could be the result of a decrease in residence time within the screenwell.
Schools of alewife have been observed to swim in the screenwell for up to several weeks at a time. It is anticipated that weaker members of the school break off, are swept downstream, and are either impinged or (more likely) diverted into the bypass. Since the size of the school (or at least that part of the school observed from the surface) appears to remain fairly stable over the period, entrapment into the screenwell must approach or equal the number diverted. If in fact the weaker fish are the ones diverted, then survival of these fish would be expected to be lower than for fish diverted in good condition. By shutting off the lights, the integ-rity of the school is lost and a portion of these fish are displaced downstream and induced to divert. Thus, a regular routine of light and dark cycles may reduce the potential for the formation of schools and thereby reduce fish residence within the screenwell.
4.0-26 I.awlcr, Matnsky E< Skelly I'.ngineers
CHAPTER 5.0 TOTAL PLANT EFFICIENCY Total plant efficiency (TPE) is a function of the TDE and the long-term survival. The total efficiency by month was determined for the 10 prevalent species according to the following formula (Table 5.0-1):
TPE = (TDE) x (SURV where TDE = proportion diverting SURV = 96-hr survival corrected for initial mortality TPE for alewife and rainbow smelt are presented by size class and month, white perch by size class for each year, and the remaining seven species for each year only. The TPE values varied widely by species, size, and season or month. TPE for juvenile and adult alewife ranged from 0 to 165 and 0 to 56K, respectively, while juvenile and adult rainbow smelt ranges were slightly higher (3 to 24K juveniles, 0 to 65K, adults).
Table 5.0-2 integrates the monthly TPE values, and the estimated entrapment rates (Table 3.0-9) over the two-year study period to provide an estimate of the number of fish, by species, returned alive to the source water body. This number then, when compared to the total number of fish entrapped, indicates the total system effectiveness for each particular species.
A further breakdown of these data (Table 5.0-3) indicates that for some species, particularly rainbow smelt, the degree of effective-ness differed significantly for different size classes. The Oswego 5.0-1 I.awlor, Matnsky 8'kolly Iinginoors
TABLE 5.0-1 HONTHLY TOTAL PLANT EFFICIENCY BY SPECIES Oswego Steam Station Unit 6 - April 1981 - Harch 1983 HONTH Apr 1981 13.3 22.6 23.8 64.6 45.7 57.2 80.1 76.4 52.0 90.5 88.2 6.6 38.0 Hay 1.0 1.6 22.1 0 Jun 1.9 7 ' 22.1 20.4 Jul 2.7 25.7 18.4 20.4 Aug 1.2 2.5 18.4 20.4 Sep 1.9 5.5 12.2 17.0 Oct 15.8 45.2 23.7 32.3 Nov 16.1 27.4 11.7 20.6 Dec 13.8 26.6 5.0 20.7 Jan 1982 0 0 4.2 44.7 Feb 3.0 7,4 3.1 38.3 Har 3.0 3.4 5.0 46.3 45.7 57.2 80.1 76.4 52.0 90.5 88.2 6.6 38.0 Apr 0 6.0 7.6 57.8 43.8 54.8 62.4 67.2 43:5 81.4 ,78.3 7.5 54.8 Hay 0 5.9 7.1 32.7 Jun 0.7 3.1 3.8 17.4 Jul 0.7 4.3 3.8 14.1 Aug 1.1 4.2 4.8 17.8 Sep 0.9 7.5 6.1 24.6 Oct 0.4 11.8 7.8 20.4 Nov 2.0 55.8 11.1 21.7 Oec 1.4 55.8 20.4 21.1 Jan 1983 1.4 55.8 16.4 16.9 Feb 1.4 55.8 16.4 16.9 Mar 1.0 41.5 18.5 19.1 43.8 54.8 62.4 67.2 43.5 81 ' 78.3 7.5 54.8 AH - Alewife GSD - Gizzard shad RSH - Rainbow smelt YP - Yellow perch NP - Mhite perch SHB - Smallmouth bass EHSH - Emerald shiner TSB - Threespine stickleback STSH - Spottai 1 shiner HOTS - Hottled sculpin X
- ~Combined across months during periods of low abundance.
TABLE 5.0-2 ESTIHATEO NUHBERS OF FISH RETURNEO ALIVE TO LAKE ONTARIO Oswego Steam Station Unit 6 - April 1981 - Harch 1983 Apr 1981 11732 5265 364 231 292 449 261 0 0 57 Hay i269 124 368 59 228 0 235 0 0 175 Jun 2975 127 71 173 165 112 195 0 0 27 Jul 4895 41 37 0 398 0 0 197 5 0 Aug 28 0 0 0 1137 0 270 1050 0 0 Sep 581 1454 0 5767 275 1142 130 0 0 274 Oct 17961 19764 3033 4941 3126 7479 357 111 0 608 Nov 1852 9883 912 2087 396 2482 195 0 112 309 Oec 361 6371 70 650 142 452 0 0 311 116 Jan 1982 0 1789 129 423 358 306 303 131 12 1419 Feb 21 213 138 775 0 63 0 237 4 181 Har 10 2319 1050 537 125 155 135 131 12 113 Apr 2262 24987 1699 490 372 60 346 23 24 225 Hay 1113 106 37 232 100 13 121 117 0 98 Jun 358 125 79 67 0 0 117 0 0 47 Jul 1216 34 163 186 175 0 121 233 0 114 Aug 84 61 544 93 340 0 321 1118 2 163 Sep 137 432 126 467 1016 94 0 208 0 59 Oct 131 222 36 158 525 113 0 49 0 367 Nov 113 584 113 0 194 335 117 16 0 205 Dec 357 117 93 0 65 0 0 0 135 Jan 1983 3 252 0 19 0 55 24 23 0 16 Feb 0 34 88 17 0 12 0 0 0 15 Har 33Z5 263 32 93 0 65 0 0 0 306 No. Returned 50481 74807 9206 17558 9364 13452 3248 3644 482 5029 Alive Total Estimated 448870 433862 18808 22598 12744 26173 3735 4389 7262 11827 Entrapment Percent 11.2 17.2 48.9 77.7 73,.5 51.4 87.0 83.0 6.6 42.5 Returned Alive AM - Alewife GSO - Gizzard shad RSH - Rainbow smelt YP - Yellow perch MP - Mhite perch SHB - Smallmouth bass EMSH - Emerald shiner TSB - Threespine stickleback STSH - Spottai shiner 1 HOTS - Hottled sculpin
diversion system effectively returned 54K of the rainbow smelt greater than 10 cm while only 105 of those 10 cm or less were returned alive to the lake. Individual size or age class was of less importance to the ultimate effectiveness of the system on alewife and white perch (Table 5.0-3).
Section 4.5 indicates that the system effectiveness could be improved by using a light/dark cycle to induce fish diversion and reduce fish residence in the screenwell. Table 5.0-4 provides the estimated results that would be expected from such a dark-induced diversion scheme. Using a study period from March 1982 through March 1983, the system effectiveness for alewife would be improved from 7 to 20K while rainbow smelt system effectiveness would be increased from 34 to 49%%d. Table 5.0-5 indicates that the dark-induced diversion is especially effective for adult rainbow smelt, providing a system effectiveness for this species/life stage of 84$ .
Thus, the use of a light/dark cycle to induce fish diversion appears to improve the effectiveness of the diversion system, especially for the adults of a given species.
5.0-4 I.awlor, iblatnskv 5" ~>knllv I'.nginoers
TABLE 5.0-3 DIVERSION SYSTEM EFFECTIVENESS FOR ALEWIFE, RAINBOW SMELT, AND WHITE PERCH BY SIZE CLASS Oswego Steam Station .Unit 6 - April 1981 - March 1983 LEWIF RAIN OW SMELT WHIT PERCH
<0 >0 <0 >0 <3 >3 No. Entrapped 145,266 303,604 363,166 70,696 12,423 6,385 No. Impinged 39,686 53,072 107,741 4,380 1,319 445 No. Diverted 105,580 250,532 255,425 66,316 11,104 5,940 No. Surviving 12,240 38,241 36,442 38,365 5,584 3,622 I Effective (TPE) 8.4 12.6 10.0 54.3 . 50.0 56.7 a
Estimate based on average monthly collection rates (No./hr) over the period April 1981 through March 1983.
b Measured in centimeters.
TABLE 5.0-4 ESTIMATED NUMBERS OF FISH RETURNED ALIVE TO LAKE ONTARIO USING DARK-INDUCED DIVERSION Oswego Steam Station Unit 6 - March 1982 March 1983 MONTH LIGHT DARK LIGHT DARK Mar 1982 10 32 23)9 3652 Apr 2262 4579 24987 32986 May 1113 7452 106 168 Jun 358 3067 125 196 Jul 1216 6930 34 55 Aug 84 643 61 82 Sep 137 50 432 2685 Oct 131 569 222 529 Nov 113 153 584 1137 Dec 4 20 357 394 Jan 1983 3 13 252 283 Feb 0 0 34 39 Mar 3375 2505 263 290 No. Returned 8806 26013 29776 42496 Alive Total Estimated 128574 128574 86265 86265 Entrapment Percent 6.8 20.2 34.5 49.3 Returned Alive bTaken from Table 5.0-2.
Estimated numbers of fish returned alive using dark-induced diversion system.
0 TABLE 5.0-5 DIVERSION SYSTEM EFFECTIVENESS FOR ALEWIFE AND RAINBOW SMELT BY SIZE CLASS USING DARK-INDUCED DIVERSION Oswego Steam Station Unit 6 - April 1981 - March 1983 ALEWIFE RAI BOW SMEL No. Entrapped 20,349 108,225 43,557 42,708 No. Impinged 6,729 34,634 13,031 3,623 No. Diverted 13,620 73,591 30,526 39,085 No. Surviving 1,021 24,992 6,816 35,680 X Effective (TPE) 5.0 23.1 15.6 83.5 a
Estimate based on average monthly collection rates (No./hr) over the period March 1983.
b Measured in centimeters.
CHAPTER 6.0 POTENTIAL FOR RECIRCULATION A special study was conducted from 14-21 April 1982 to evaluate the potential for recirculation of fish from the offshore discharge to the offshore intake. The proximity of the discharge to the intake (82.7 m; 271 ft) makes it feasible that a portion of the discharged fish are re-entrained at the intake, thereby affecting the estimated numbers impacted and the anticipated survival for fish subjected to multiple passes through the system.
To evaluate the degree of recirculation, 1103 live tagged adult rainbow smelt were released into the bypass slot of the secondary screenwel 1 on 14 April 1982 coincident with high, naturally occur-ring smel t abundances ~ Impingement and bypass fish were then monitored continuously at Unit 6 for the next seven days. Impinge-ment at Units 1-4 and Unit 5 was. also continuously monitored for I
tagged smelt.
A summary of the release and recovery results is presented in Table 6.0-1. Of the 1103 live tagged smelt that were released only three
((1X) were recovered in Unit 6. None were recovered in Units 1-4 or Unit 5. Since all the recoveries were made within five days of the release (two of the three within the first 29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br />) it is unlikely that additional smelt would recirculate after seven days had elapsed.
The degree of recirculation of adult rainbow smelt from the offshore fish discharge to the offshore intake appears negligible. This is probably the case with other commonly entrapped species, but the lack of sufficient numbers for testing precludes analysis of other species.
6.0-1
TABLE 6.0-1 RAINBOW SMELT RECIRCULATION STUDY Oswego Steam Station Unit 6 21 April 1982 DATE TIME NUMBER RE AP URE 0 T TIME LAP ED RELEASED RELEASED RELEASED LOCATION NUMBER RECAPTURED RECAPTURED TIME 14 Apr 1982 1245 1103 Unit 4 Impingement Unit 5 Impingement Unit 6 15 Apr 1982 1739 28.9 hr Impingement Unit 6 15 Apr 1982 1329 24.7 hr Sample Basin
'000 Unit 6 19 Apr 1982 107.2 hr Sample Basin
CHAPTER 7.0 ASSESSMENT OF PREDATOR POPULATION From April'hrough Nov'ember 1982, 13 gi1 1 net surveys were per-formed to assess the potential for predation of fish exiting the Uni t 6 diversion system (Tabl e 7.0-1) . In order to observe the maximum potential for predator attraction, the surveys were sched-uled to coincide with periods of high fish diversion. Thus, the major sampling effort was expended during the spring of 1982 with lesser effort expended during the subsequent fall.
Gill net samples were collected at the fish discharge nozzle located approximately 300 m (1000 ft) northwest of the Unit 6 screenhouse and at a control site approximately 0.8 km (0.5 mi) west of the fish discharge and 300 m (1000 ft) offshore north of S.U.N.Y.
Oswego. All samples were collected with a 30.8 x 3.1-m (100 x 10 ft) multifilament gill net with 12.7-cm (5 in.) stretch mesh de-ployed on the bottom along the 8 m (25 ft) depth contour. The net was set parallel to shore at each station. Predation surveys were normally overnight sets of 12- to 24-hr duration. When weather conditions on Lake Ontario prevented safe sample retrieval, the collections exceeded 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Upon removal from the net, each potential predator was identified, its condition noted, and it was placed on ice in a labeled cooler for subsequent analysis. All predator species captured received individual length and weight measurements and examination'or general body condition and tags.
The most abundant predator species in the collections were lake trout, =Salvelinus namaycush (59 captured), followed by smallmouth bass, Micropterus dolemieui (20), and brown trout, Salmo trutta 7.0-1 Lawlcr, iIlatnsky E~ Skelly I'.ngineers
TABLE 7.0-1 PREDATION SURVEY SAMPLE DATES FOR 1982 Oswego Steam Station Vicinity 28 Apri 1 30 Apri 1 19 May 24 May 25 May 26 May 15 June 27 June 28 July 9 September 21 September 6 October 17 November 7.0-2
( 14). The remaining species (walleye, Stizostedion vitreum; Ameri-can burbot, Lota iota; Rainbow trout, Salmo Sairdneri; chinook salmon, Oncorhynchus tschawytsch a; and Coho salmon, Oncorhynchus kisutch) were represented by fewer than five individuals each (Table 7.0-2). Salmonids were present in every collection but most abun-dant in late spring and late fall with a peak in May. Smallmouth bass were present from April through October but most abundant in May and September. American burbot were captured only in May and walleye were collected intermittently from April through September.
The total number of predators captured at each site was almost equal (Control-54, Oischarge-52). Of the most frequently encountered predator species, only smallmouth bass seemed to have any preference between sites. In May, six bass were captured at the control site and none at the discharge. This may be more closely related to pre-spawning movements than to feeding habits. There is no evidence of greater predator abundance in the vicinity of the fish discharge than in similar nearby habitats.
- 7. 0-3 l,nwler, Matusky O'kelly Engineers
TABLE 7.0-2 FISH COLLECTEO IN 12.7-cm 5-in. STRETCH-NESH GILL MET Oswego Steam Station Vicinity - 1982 SPECIES Z6HTR~P'STlS~HF UJHTRO~F MTK~" UJHTRO~F MTK6~r Z6RTR6~ZF RUHR~
Smallmouth bass 1 1 6 1 1 2 3 4 1 12 8 Brown trout 3 1 2 1 6 1 6 8 Malleye 1 1 1 1 2 2 2 Chinook salmon 1 I 1 1 Lake trout 15 15 ll 10 3 5 29 3
30 0
American burbot 3 Coho salmon 1 0 1 Rainbow trout 1 1 1 2
. . 3 6 54 52 Total 5 2 25 17 14 12 3 3 3 11 1 1 Hean Temp. 7.2 7.7 7.4 7.2 11.5 12.1 22.2 22.1 17.1 17.0 15.8 15.8 8.2 8.4 (surface) ('C)
CHAPTER 8.0 0 I SCUSS ION The objective of the two-year research program was to assess:
- 1. The efficiency of the angled screen
- 2. The effectiveness of the 'fi'sh bypass
- 3. The viability of any organism that successfully enters the bypass system and eventually returns to Lake Ontario The efficiency of the angled screens and the effectiveness of the fish bypass is discussed in detail in Chapter 3.0. In general, the angled screen system is effective in diverting fish from the primary screenwell, through the secondary screenwell, and back out to the lake. Oegree of effectiveness varied widely by species, size class or age, and season, but overall effectiveness (composite across entire project duration, i.e., size class and season) for the 10 dominant species ranged from 531 for mottled sculpin to 94K for gizzard shad (Table 3.0-16). The distinctive behavior of the mottled sculpin contributed to its low diversion efficiency.
Because of its poor swimming ability and demersal preference, this species typically seek out the bottom or other substrate upon which to rest. In the lake, mottled sculpin were never observed swimminq in the water column. Once in the screenwell, this species rested on the vertical traveling screens and was removed from the water column as the screens were rotated and washed.
At 78 and 74K, respectively, alewife and rainbow smelt diversion efficiencies appeared low. Studies conducted by Taft and Hussalli
( 1978) upon which the Oswego diversion system was designed, indicate I.awlcr, Matusky O'kolly I'.nginoers
I that alewife and rainbow smelt diversion efficiencies in their test flume were typically at or near 100K. However, assuming the 'labora-tory tests used only hardy test specimens under controlled condi-tions, then the laboratory results could legitimately be compared with the upper portion of the range observed in the test results; i e., 98K for alewife and 99K for rainbow smelt (Table 3 0 16).
The results described in Chapter 3.0 indicate that, depending upon the condition of the entrapped population and their age or size, the range of observed diversion efficiencies can approach the range represented by the laboratory study.
Adult alewife in good condition (April 1981) demonstrated a 98K diversion efficiency, while the same age class one year later (coincident with a substantial local alewife die-off) demonstrated only a 41K diversion efficiency (Table 3.0-16). Although condi-tion factor analysis (Everhart et al. 1975) indicated no significant difference in condition (as described by a length-weight relation-ship) between the two populations, the presence of the massive mortality in 1982 (not observed in 1981) indicates that the April 1982 population was, in fact, responding adversely to an environ-mental stress.
An equally important variable in assessing diversion effectiveness was age class. The adults, which typically dominated the spring collections, provided higher diversion efficiencies (83K for alewife and 94K for smelt) than the YOY fish which dominated the. fall and early winter collections (73$ for alewife and 70Ã for smelt) (Table 3.0-17).
The other objective of the study was to identify the viability of the fish following diversion and upon return to the lake. Sampling was conducted primarily in-plant from a sampling point just prior to 8.0-2 Lnwlcr, bIatnskv P'kclly I',nginccrs
f inal transport offshore (Section 4.1) . Addi tional col lections were made offshore to determine if there was any major source of mortality associated with the transport process.
As demonstrated in the diversion efficiency results, variability in the survival results was related primarily to condition of the population and secondarily to the age or size class of the individuals. In turn, condition of the entrapped population was dictated by natural environmental conditions (i.e., water tempera-ture, food availability) and reproductive state (i.e., sexual maturity). Yiability results for the two dominant species, alewife and rainbow smelt, are presented and discussed in detail in Chapter 4.0 (Table 4.0-4). Seasonal trends were related to reproductive state with the highest survivals occurring just prior to spawning and the lowest survivals occurring just after spawning. Adult alewife survivals ranged from 2 to 63K, with YOY survival substan-tially lower, 0 to 20K. Rainbow smelt fared better, with adult survivals ranging from 0 to 70K, and YOY smelt survival falling between 5 and 32K. Taft and Mussalli (1978) reported a mean differ-ential mortality of 35.7 + 13.5$ (survival = 64.3X) for alewife and attributed the low survival to difficulty in handling this fragile species in the model facility. When they combined the diversion test apparatus with the transport system and thereby reduced the handling, their mortality decreased to only 4X (survival = 96K).
Several factors might have contributed to the differences between their laboratory results and the actual findings in the operating system. Based on the results of this study, the condition of the fish at diversion is a primary factor in determining whether or not the test organism will survive passage through the diversion system. In the study reported by Taft and Hussalli, the test fish were collected, transported, and acclimated to the holding appa-ratus. Mortality resulting from this handling culled the weaker individuals from the test population. Testing was conducted 8.0-3 Lawlor, iWutiisl<v 6" Bkvlly I'.nginoors
primarily on subadul t and adult alewife rather than on the more sensitive YOY. Because of time constraints, flume experiments were limited in duration, and the effect of long-term residency was not evaluated.
In contrast, the fish tested in this study are those that were entrapped at the offshore velocity cap intake and transported through the turbulent intake tunnel, approximately 370 m (1200 ft) to the primary screenwell where the flow enters the screenwell through a vertical intake shaft rising approximately 30 m (100 ft) in 20 sec. The fish then encounter the vertical bar racks and the angled screen diversion system. During the period November through April, the organisms also encounter tempering in the primary screen-well, which subjects them to a turbulent boil and an immediate increase in temperatures of from 2 to 8 C.
Thus, while the diversion system may provide high survival results under laboratory conditions for alewives that are in good condition, the components associated with an offshore cooling water intake system may not transport the test specimens to the diversion system in the best of condition. This factor is evident in the results of the fragile species; alewife, gizzard shad, juvenile rainbow smelt, and threespine stickleback. The hardy species, the salmonids, smallmouth bass, and rock bass, appear to be less affected by the intake system and are capable of handling the cumulative stress of the transport to, and the passage through, the diversion system with minimal mortality.
In terms of overall system effectiveness, only 17 and 11K, respec-tively, of the rainbow smelt and alewife entrapped in the OSS-6 cooling water system were returned to the lake and were expected to survive. In contrast, 87 and 835, respectively, of the yellow perch and smallmouth bass were effectively returned to the source 8.0-4 Laivlor, Matusky O'>kolly I',nginoors
water body (Table 5.0-2). Upon further breakdown, 54K of the adult smelt were estimated as survivors but only lOX of the YOY would pass through the system and return offshore in any condition to survive.
Alewife survival of the two size classes differed much less (135 for subadult/adults and 8X for YOY). Fifty-seven percent of the adult white perch survived the diversion system vs 50K of the YOY (Table 5.0-3). These findings are important in terms of impact assessment or differential cropping of vari'ous age classes and the effect on reproductive capacity. They are also critical for estimating potential effectiveness of the angle screen diversion system at other sites.
The total estimated entrapment for the two-year study period is 1,026,812 fish. The 10 species presented in Table 5.0-2 account for 990,268 fish or 96K of the total estimated entrapment at Osweqo Unit
- 6. Of these, 187,271 fish or 185 were returned alive to the lake and were expected to survive. Thus, in the most basic terms, the
-6 angled screen -fish diversion system is reducing the total OSS-6 plant cropping and thus its impact by approximately 18K.
The overall effectiveness of the system on the game species (white perch, rock bass, yellow perch, smallmouth bass, brown trout, white bass, chinook salmon, rainbow trout, and largemouth bass) was approximately 65K. Of the 34,200 estimated game fish entrapped over the two-year period, 18,808 (551) were white perch with a 49K recovery rate. The remai ring 15,392 were primarily smallmouth bass and yellow perch with 83 and 87K recovery rates, respectively.
'Based on the findings of increased survival subsequent to dark-induced diversion (Section 4.7), the overall efficiency of the diversion system can be i ncreased appreciably through regulation of a light and dark cycle. An 'estimate of 128,574 alewives were entrapped during the 13-month period from March 1982 to March 8.0-5 Lawlor, Mntnsky 6" Bkelly 1'.nginoers
1983. Under normal light diversion conditions 8806 (7X) of the entrapped alewife were returned offshore and n were we expected to survive. Based on the dark-induced survival results, the same period would return 26,013 (205) of thee en t rapped alewives safely (Table 5.0-4).
Results for rainbow smelt were not as dramatic i . T o t a 1 p 1 ant effic-iency for smelt, based on light diversion was 34K, as compared to 49K, using a dark-induced diversion Add't' i iona investigations into li the use of a 'g ht//dark regime for improvement of alewife and rainbow smelt diversion and subsequent surviva s is currently being conducted and will be reported in a later report.
The investigations conducted on the Oswe go St earn S tation Unit 6 angled screen diversion system can be summarized as follows:
Mechanically and hydraulically, the system is functioning as designed with minimal o pera t iona 1 problems.
- 2. Oiversion of fish across the angled screens scree is hi'g hl y d ependent upon species, their condition (i.e., physiological and/or reproductive state),
and their age or size class.
- 3. The fragile species (alewife, gizzard shad, juve-nile smelt) are more susceptible to impingement than are the hardy species (salmonids, smallmouth bass, rock bass, yellow perch).
. 4. Unless weakened by recent spawning activities, adults of a species typically exhibit a higher diversion efficiency than the young.
- 5. Survival following diversion was also dependent upon species, their condition, and their age or size class.
- 6. Survival results based on offshore collections indicated that in-plant collections provided a good estimate of ultimate survival upo pon d isc h arge offshore.
8.0-6 Lawler, Matnsky 6" Skelly 1'.ngineers
- 7. The condition of the alewife population at the time of entrapment and the stresses applied to the population upon transport to the screen-well most likely account for the substantial differences in survival results observed in laboratory studies and the actual installation.
- 8. Overall TPE varied from 6.6 to 17.8X for the fragile species (threespine stickleback, alewife, and rainbow smelt) to 73.5 to 87.0% for the hardy species (spottai 1 shiner, emerald shiner, smallmouth bass, and yellow perch).
- 9. The angled screen diversion system is an appli-
'cable and proven technology that will operate with minimal additional maintenance beyond that required for the traditional vertical traveling screens. tts effectiveness as a mitigation device will depend upon the species of interest, their age or size class, and the condition in which the individuals are delivered to the system.
8.0-7 Lawlcr, Matusky O'kelly I',ngineers
REFERENCES CITED Bates, D.W., and J.G. VanDerwalker. 1970. Preliminary designs of traveling screens to collect juvenile fish. U.S. Fish and Wildlife Service. Special Rep. No. 608.
Brown, E.H., Jr. 1968. Population characteristics and physical condition of alewives, Alosa pseudoharen us in a massive die-off in Lake Michigan, 1967. Great La es Fss . Comm. Tech. Rept.
No. 13.
Colby, P.J. 1971. Alewife die-offs: why do they occur? Limnos 4(2):18-27.
Eicher, G.J. 1960. Fish bypass experience at PGS's new hydro projects. Electric Light and Power: 62-64.
Everhart, W.H., A.W. Eipper, and W.D. Youngs. 1975. Principles of fishery science, p. 288. Comstock Publishing Associates.
Farr, W.E. 1974. Traveling screen for turbine intakes of hydro-electric dams, p. 199-203. In L.D. Jensen (ed.), Proceedings of second entrainment and intake screening workshop. Johns Hopkins University Cooling Water Research Project Rep. 15.
Gunsolus, R.T., and Eicher, G.J. 1950. Evaluation of fish passage facilities at the North Fork Project on the Clackamas River in Oregon. The Fish Commission of Oregon and Portland General Electric Co.
Marquette, W.M., and C.W. Long. 1971. Laboratory studies of screens for di verting juvenile salmon and trout from turbine intakes. Trans. Am. Fish. Soc. 100:439-447.
Schuler, V.J. 1973. Experimental studies in guiding marine fishes of Southern California with screens and louvers. Prepared for Southern California Edison Company. Ichthyological Associates Bull. 8.
Schuler, V.J., and L.E. Larson. 1973. Fish guidance and louver systems at Pacific Coast intake systems. Presented at Johns Hopkins University workshop on entrapment and entrainment.
Stone and Webster Engineering Corporation (SINEW). 1977. Studies to alleviate potential fish entrapment at Unit No. 6 - Oswego Steam Station. Prepared for Niagara Mohawk Power Corporation.
Taft, E.P ., and Y.G. Massalli . 1978. Angled screens and louvers for diverting fish at power plants. Proc. Am. Soc. Civ. Eng.,
J. Hydraul. Div. 104:623-634.
R-1 Lawler, Matnsky K Skelly Engineers
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