HomeMy WebLinkAboutPreliminary Environmental Analysis of the Unalaska Geothermal Power Project 1986
UNA
046
Preliminary
Alaska Energy Authority
LIBRARY COPY
PRELIMINARY .ENVIRONMENTAL ANALYSIS OF
THE UNALASKA GEOTHERMAL POWER PROJECT
by
Kimbal A. Sundberg, Brad L. Hahn,
Len J. Vining, and C. Wayne Dolezal
State of Alaska
Department of Fish and Game
Habitat Division, Region IV
Lance L. Trasky, Regional Supervisor
Submitted to
Alaska Power Authority
December 1986
UNA OY STATE OF ALASKA /rne ove i
DEPARTMENT OF FISH AND GAME 333 RASPBERRY ROAD ANCHORAGE, ALASKA 99502-2392
December 5, 1986
Mr. David Denig-Chakroff
Unalaska Geothermal Project Manager
Alaska Power Authority
P.O. Box 190869
Anchorage, AK 99519-0869
Dear Dave:
The Alaska Department of Fish and Game is pleased to provide
ten copies, of our report entitled, "Preliminary
Environmental Analysis of the Unalaska Geothermal Power
Project" to the Alaska Power Authority (APA). In the
preliminary report we have addressed several potential
project alternatives, knowing that the alternatives will be
narrowed down as the feasibility study proceeds. We will
need your continued guidance and suggestions to ensure that
we address the most appropriate project features in our
final report.
We have enjoyed working with both you and Brent Petrie on
the Unalaska Geothermal Power Project and hope that our
participation has helped the APA in assessing the
feasibility of this project. Please contact Kim Sundberg
(267-2334) if you have any comments. or questions concerning
this report.
Sincerely,
bang L. asky
Regiohal 6upervisor
Region IV
Habitat Division
Enclosures
cc: Norman A. Cohen
PRELIMINARY ENVIRONMENTAL ANALYSIS OF
THE UNALASKA GEOTHERMAL POWER PROJECT
by
Kimbal A. Sundberg, Brad L. Hahn,
Len J. Vining, and C. Wayne Dolezal
State of Alaska
Department of Fish and Game
Habitat Division, Region IV
Lance L. Trasky, Regional Supervisor
Submitted to
Alaska Power Authority
December 1986
TABLE OF CONTENTS
Section Page
INTRODUCTION... ccc ec eee c cece ccc r ccc ccc ccccccccccccceeee lL
PART I: FISH HABITAT SURVEY
I-1.0 Executive Summary......... Swen esses sw sapeccsse cess
I=-2.0 Methods... cece ccc ccc cere cece ccc cece ccc ese rscecees
I-3.0 Results and Discussion..... os cic eo cee s eee se esse ces
3.1 Makushin Valley......... cc ccc cece cee cee ee eee o
3.1.1 Pink Salmon... cc cece wee cece cee ween
3.1.2 Coho Salmon...... cece eee cece cece eee eee
3.1.3 Chum Salmon........ cece ec eee eee eee wees
3.1.4 Dolly Varden....... 2... cece eee eee ee eee eee Ll
3.2 Driftwood Valley...... wcrc ccccccccccsccccoscces LI
3.2.1 Pink Salmon......... cece eee ee eee eee eee 11
3.2.2 Coho Salmon... ... cece eee ee ee eee eee eeee 14
3.2.3 Dolly Varden.............. eo ceceescone -. 14
3.3 Glacier Valley... cc cece eee eee ce ee eee reece 14
3.3.1 Pink Salmon....... ccc cece cece ec eee seen 14
3.3.2 Dolly Varden... .... cee cece eee eee eee eeee LS
Nateekin Valley.......... cece eee e cece eee eee eee LS
Water Quality. .cwcereeevecceseeveceseeseccseees 15
Human USC... cece cc cccccc ccc cccccc ccc cc cccecccce 20 WUWONDANNN WWW oe an PART II: POTENTIAL EFFECTS OF UNALASKA GEOTHERMAL POWER
PROJECT ON FISH AND WILDLIFE
II-1.0 Executive Summary............ccceecceees wieocsoece 23
TI-2.0 Methods... cece ccc ccc cc cc ccc ccccccccccccceeee 24
II-3.0 Development Scenario..... ccc cece cece cree cesecee 25
II-4.0 Potential Effects... cccccccccrcccccccccccscese 25
4.1 Direct Physical Effects............cce eee eeeeeee 25
4.1.1 Stream Crossings.......... og ees os oss ccs 26
4.1.2 Surface Drainage Patterns............... 27
BEOSIGH 6 eho oc ok teres cece cts sbeceecseesscoes 27
Surface Water EffectS......... cece ees ccecces “ee. 28
4.3.1 Temperature... .... ccc cee ee ce eee eee eee ee 29
4.3.2 AYSENIC.... cece ce ec cece rece c rece eeevee 30
4.3.3 Hydrogen Sulfide..............02e eee eee 31
4.3.4 Supersaturated Gases..........-22222---- 31
4.3.5 Lead, Mercury, and Cadmium..... ee csasees 32
Ground Water Effects... ..... cece eee cece rece ecee 32
Air Pollution... ...ccccceccccccccccsccrccvcs eee. 33
Noise......... cece ccc cee c cc eccccenes beescsescoce 33
Human PresSence...... cece cccecccces iste ew Gecsss 3S
AcCIideNtsS. coc ere ccc ccc cere cc ccecccces eececene -. 34 > > ee Wn PPP PL ee ONIHDWN eee ii
Table
LIST OF TABLES
Results of Minnow Trapping, Electrofishing,
and Observations in Makushin, Driftwood,
and Glacier Valley Streams (September 2-5,
1986)... ccc cccccvcccvccccces eee c ccc ccccscccce
Pink Salmon Escapement Estimates for
Makushin Valley...............
Pink Salmon Escapement Estimates for
Driftwood Valley.......... 2. cee cece cece eens
Pink Salmon Escapement Estimates for
Glacier Valley......... ccc cece cece ce ee wees
Salmon Escapement Estimates for Nateekin
River...... tlolelelcllelsle a6 oe lols so & ole lalolels co 4 eo wlelels oi |e
Water Quality at Fish Sampling Sites in
Makushin, Driftwood, and Glacier Valleys
(September 3, 1986) ....... ce eee cece cence eens
Pink and Coho Salmon Commercial Catch for
Unalaska Bay and Makushin Bay Statistical
Aveas, 1979=86. 2... cc cee cece ccc ccs ec ese sews cs
List of Environmental Permits That May Be
Required for Construction and Operation of
the Unalaska Geothermal Power Project........
iii
13
16
17
19
21
Figure
LIST OF FIGURES
Page
Length Frequency Histogram for Juvenile
Coho Salmon Captured in Makushin Valley
(September 2-3, 1986).......... aes eles! al ellelsllerelie's 10
Length Frequency Histogram for Dolly Varden
Char Captured in Makushin Valley (September
2-3, 1986) . cee cwecrcccccccccesccccccccccesces bf
iv
Appendix
LIST OF APPENDICES
Scale Analysis of Coho Salmon Collected from
Makushin and Driftwood Streams
‘Fish Collected by Electrofishing and Minnow
Trapping in Makushin Valley (September 2-3, 1986)
Fish Collected by Electrofishing in Driftwood
Valley (September 2-3, 1986)
Fish Collected by Electrofishing and Minnow
Trapping in Glacier Valley (September 2-4, 1986)
ADF&G Culvert Installation Guidelines
LIST OF PLATES
Plate Location
bt Makushin Valley Area................... Map Pocket
2 Driftwood and Glacier Valley Areas..... Map Pocket
vi
INTRODUCTION
In September, 1986 the Alaska Power Authority (APA)
contracted with the Alaska Department of Fish and Game
(ADF&G), Habitat Division to assist in identifying potential
impacts, mitigation, and permitting requirements for six
rural energy development projects in southwestern Alaska,
including the Unalaska Geothermal Power Project. The scope
of work for Unalaska Geothermal Power Project includes:
conducting limited field surveys as necessary to obtain
. information on fish and aquatic resources to evaluate the
potential effects of the proposed geothermal project,
identifying project-related fish and wildlife issues,
determining how geothermal fluids may affect important
aquatic resources, reviewing and commenting on appropriate
project documents, summarizing literature, and developing
contacts with persons familiar with similar projects outside
of Alaska.
This preliminary report is divided into two parts. Part I
contains the results of a fish and aquatic habitat survey
conducted during September 2-5, 1986 in the Makushin,
Glacier and Driftwood valleys and summarizes salmon
escapement data for Nateekin Valley. Part II contains a
preliminary discussion of the potential effects of the
Unalaska Geothermal Power Project on the fish and wildlife
resources of Unalaska Island. Recommendations for
mitigating project impacts and further study are also
provided.
At present, neither the retrieval of literature nor the
evaluation of potential effects is completed. However, this
preliminary report provides a clear indication of the
direction and scope intended for the final report.
PART I
FISH HABITAT SURVEY
I-1.0 Executive Summary
The distribution and relative abundance of salmonids were
evaluated in the Makushin, Glacier, and Driftwood valleys.
Juvenile fish were sampled by electrofishing and minnow
trapping. Helicopter surveys were flown to enumerate adult
salmon and to determine salmon spawning areas. Weather and
visibility conditions were favorable during the survey which
allowed the entire study area to be examined.
Makushin Valley contained pink, chum, and coho salmon and
Dolly Varden char. Both chum and coho’ salmon were
previously undocumented for this valley. Spawning by salmon
was observed in the lower 5.3 miles of the main stem and
side tributaries. Spawning by char was observed in the
vicinity of River Mile (RM) 6.3.
Driftwood Valley contained pink and coho salmon and Dolly
Varden. Spawning by pink salmon was observed in the
vicinity of the lower road crossing and up to approximately
RM 2.5. Young-of-year juvenile coho salmon and Dolly Varden
were found in the vicinity of the lower road crossing. No
fish were found in the vicinity of the upper road crossing.
Glacier Valley contained pink salmon and Dolly Varden. The
largest number of pink salmon were found in the lower 1.5
miles of a tributary on the east side of the valley. Dolly
Varden were found in spawning colors and in suitable
spawning habitat in the vicinity of RM 5.3.
I-2.0 Methods
During September 2-5, 1986 aerial surveys of fish habitat in
the Makushin, Glacier, and Driftwood valley streams were
‘conducted using a Bell 206-B helicopter. The Nateekin River
was not surveyed because it has not been identified for
geothermal project impacts and because of time limitations.
The objectives of the survey were to: (1) determine adult
salmon distribution and abundance (escapement) ,
(2) determine streams and portions of streams used for
spawning by resident and anadromous fish, and (3) identify
potential rearing areas for juvenile fish.
Based on visual assessments during aerial surveys, eight
sampling sites were selected in potential salmon rearing
areas (i.e., side sloughs, pools, and spring fed
tributaries). Sampling sites are shown on Plates 1 and 2.
-2-
At each sampling site, an effort was made within the time
allowed to sample sufficient areas to determine the general
distribution and upper limits of salmon in the valley
streams. :. The sites were sampled using a backpack
electrofisher (Smith & Root Model 11-A) and minnow traps
baited with cured salmon eggs. All captured fish were
identified to species and their fork length was measured to
the nearest millimeter (anterior extremity to fork in tail).
Juvenile salmon from each sampling site were sacrificed and
preserved in 75 percent propanol for later scale analysis.
The remaining fish were returned to the stream.
Water quality parameters including temperature,
conductivity, pH and dissolved oxygen were measured in situ
using a Hydrolab Digital model 4041 portable water sampler.
The water sampler was calibrated prior to field data
collection.
Aerial surveys were conducted from both a helicopter and a
Grumman Goose. From the helicopter, streams were surveyed
from approximately 100 feet (ft) above ground level (AGL),
with two observers wearing polarized glasses. Escapement
estimates for the Driftwood and Makushin valleys were made
from the helicopter flying at approximately 50 knots and
counting individual and groups of fish with a hand tally
counter. Escapement estimates for Glacier Valley were made
-by a single observer flying in a Grumman Goose at
approximately 400 ft AGL and 100 knots.
Aerial survey data is an estimate of actual adult salmon
numbers. Widely varying survey conditions including
weather, type of aircraft, ambient light, stream
transparency, sinuosity, and differences between observers
all affect the accuracy of counts. Comparisons of data
between different streams and different survey years can be
useful for determining relative abundance and trends but
conclusions should be qualified in light of the survey
conditions noted in the remarks.
I-3.0 Results and Discussion
Survey conditions were favorable during September 2 and 3.
Adequate light and mild weather allowed for electrofishing,
minnow trapping, and stream observations in the Makushin,
Driftwood, and Glacier valley streams. However, minnow
traps that were set in Glacier valley streams on September 3
could not be retrieved until September 5 because high winds
on September 4 prohibited use of the helicopter. The
results of electrofishing, minnow trapping, and stream
observations are shown in Table 1.
Table 1. Results of Minnow Trapping, Electrofishing, and Observations in Makushin, Driftwood, and Glacier Valley
Streams (September 2-5, 1986).
Sampling 1/
Site Sampling Method Catch CPUE=
Makushin
M1 Electrofish (5.3 min) 27 DV- 5.1
M1 Minnow Trap (2 traps, 10 DV
each fished 20 hrs)
M2 Electrofish (11.6 min) 88 DV 7.6
M2 Minnow Trap (2 traps, 19.-DV.
each fished 20 hrs)
M3 Electrofish (18.0 min) 79 DV 4.4
5 CO 0.3
M3 Minnow Trap (2 traps, 41 DV
each fished 19.5 hrs) 7 CO
M3 Ground Observation 100 P adults
3 CH adults
1 CO adults
M4 Electrofish (6.0 min) 13 DV 2.2
13 co 2.2
M4 Minnow Trap 22 DV
(2 traps, each 18 CO
fished 17 hrs)
M4 Ground Observation 50 P adults
M-A . Aerial Observation 7,800 P adults
Driftwood
D1 Electrofish (8.7 min) 7 DV 0.8
3 CO 0.3
D2 Electrofish (1.8 min) No fish 0.0
D-A Aerial Observation 1,000 P adults
Glacier
Gl Electrofish (1.7 min) 8 DV 4.8
Table 1 continued.
Sampling : 1/
Site Sampling Method Catch CPUE =
Gl Minnow Trap 22 DV
(2 traps, each fished
43 hrs)
G2 Minnow Trap 27 DV
(2 traps, each fished
45 hrs)
G2 Ground Observation 200 P adults
G-A Aerial Observation 43,000 P adults
1/ =" Catch Per Unit Effort (CPUE)
= Number of fish caught divided by number of minutes of
shocking.
P = Pink salmon
CO = Coho salmon
CH = Chum salmon
DV = Dolly Varden char
3.1 Makushin Valley
Makushin Valley streams contained pink (Oncorhynchus
gorbuscha), coho (O. kisutch), and chum (0. keta) salmon and
Dolly Varden char (Salvelinus malma). Chum and coho salmon
have not previously been documented in the Makushin Valley.
During this sampling period, salmon were distributed in the
main stem and side tributaries from tidewater up to RM 5.3.
Dolly Varden were distributed throughout the main stem and
tributaries from tidewater up to at least the mouth of
Makushin River Canyon (RM 7.2). A previous study (Dames &
Moore, 1983) documented Dolly Varden in the canyon up to a
point below the ST-1 well site (Plate 2) where a fish
passage barrier exists.
3.1.1 Pink Salmon
Pink salmon were observed spawning in the main stem, side
channels, and tributaries of the Makushin River. Additional
pink salmon were schooled and moving upstream during the
survey. Small numbers of carcasses and moribund fish were
also seen indicating that the spawning period had already
commenced. Historical information indicates the period for
pink salmon spawning in the Unalaska Bay area is between
July 20 - September 30. The most concentrated spawning
activity appeared to be in the main stem and side
tributaries below RM 3. The upper limit of concentrated
spawning activity in the Makushin Valley was approximately
delineated by the remains of a wooden bridge that was part
of the road linking Broad Bay and Driftwood Bay during World
War II. Moderate spawning activity was noted in side
channels and tributaries up to approximately RM 4.5. Light
spawning activity was observed between RM 4.5 and RM 5.3.
Based on past aerial surveys, ADF&G biologists have noted
that the upper limit of salmon spawning is near to a lone
spruce tree at approximately RM 5.3. However, suitable
spawning habitat appears to occur upstream of this tree to
the mouth of Makushin Valley Canyon. Whether salmon use
this upper valley habitat for spawning is probably dependent
on the magnitude of escapement.
Table 2 summarizes adult pink salmon counts for the Makushin
Valley from 1961-1986. On September 2, 1986, a detailed
helicopter survey of all the waters within the Makushin
Valley produced a total estimated escapement of 7,800 pink
salmon. In recent years, the largest runs of pink salmon
have occurred during the even-numbered years. The peak
recorded escapement for the Makushin Valley occurred in 1960
when 100,000 pinks were estimated. The decline in even-year
escapements since 1982 cannot be explained from existing
data. However, pink salmon escapements are affected by many
-6-
Table 2.
Date
8-12-61
8-09-62
7-26-63
8-13-64
7-19-67
7-31-67
8-02-68
8-10-68 8-18-68
7-30-69 8-05-69
8-08-70 1 mp Wr ‘ SN 9-11-72
8-14-73
8-09-74
8-02-75
8-08-75
7-28-77
9-07-77
7-28-78
Pink Salmon Escapement Estimates for Makushin Valley. .
Count2/
7.0 - 8.0
0.0
9
15.0
NA NA
100.0
25.0
60.0 - 75.0
NA NA
10.0
NA NA
0.15
NA
2.0 - 3:0
NA NA
NA 0.05
0.5 - 0.7
Davenport
Hennick
Hennick
Davenport
Wienhold
Davenport
Davenport
Davenport
Davenport
Davenport
Davenport
Tamburel1
Davenport
Shaul
Davenport
Davenport
Davenport
Davenport
Davenport
Nelson
Observer(s)
Lall & Hennick
i
Remarks=/
Fair escapement
Muddy, fish in lst 2 mile
Glacial, visibility nil
Too muddy for survey
Too muddy for survey
Most in 1st 1.5 mile
Muddy, nothing new in
Poor light, dark bottom
Very muddy
Too muddy for survey
Estimate - counted only
2,300 because water murky
Water murky - no fish seen
Muddy water, no fish
evident, fish utilize
stream to where road
switches back up
mountains and probably up
left fork above road
Poor visibility, dark
bottom, probably more
fish
Muddy, no sign of fish
anywhere
Estimate, murky, counted
only 200, channel
unstable
Too muddy for survey
Muddy but no sign of fish
Too muddy for survey
All spawnouts, very turbid
All 1/3 - 1/2 mile up
Table 2 continued.
Date Count2/
8-06-78 0.3 - 0.4
9-05-79 62.0
7-30-80 NA
8-06-80 NA
8-12-80 3.0
8-19-80 2.8
9-09-80 34.0
8-10-81 2.0
8-22-81 3.2
9-09-81 3.3
7-23-82 0.7
8-02-82 8.0
8-12-82 71.0
9-03-82 37.0
9-19-82 13.5
+ 10,000
carcasses
8-20-83 NA
9-04-83 NA
8-07-84 21.0
8-31-84 31.0
9-02-86 7.8
1/
Observer(s)
Griffin
Shaul
Shaul
Shaul
Shaul
Shaul
Shaul
Shaul
Malloy
Shaul
Griffin
Shaul
Malloy
Shaul
Holmes
Griffin
Shaul
Shaul
Shaul
Shaul
Remarks2/
Very murky
Too muddy for count
Too muddy for count
Very clear, 3 boats
300 in upper portion
7 boats
All in clear tributary,
main stem muddy
Good visibility
Helicopter survey, some
spawning
Helicopter survey
Helicopter survey,
lower stream only
Stream murky
Nothing in stream or at
mouth
Many spawning
Helicopter survey, good
visibility
2/ Estimated escapement in thousands of pink salmon.
=’ Unless otherwise noted, all counts are from fixed wing aircraft.
NA = Not attempted.
Source: ADF&G, 1979-1985 and this survey.
factors including egg survival, ocean survival, and harvest.
Pink salmon have a two year life history with no freshwater
rearing phase. The juvenile .fry/smolts are believed to
outmigrate from Makushin Valley between February 21 -
April 15 (Arnie Shaul, pers. comm.).
3.1.2 Coho Salmon
Except for one adult coho salmon observed at sample site M3,
all of the coho salmon observed or captured were juveniles.
Coho salmon were found in clear water tributaries in the
Makushin Valley below RM 5.
Based upon information from Unalaska Creek, the spawning
period for coho salmon in this area occurs from July 15 -
January 15. The densities of rearing coho salmon appeared
to increase in the lower portions of the valley. The Catch
Per Unit Effort (CPUE) for coho salmon was seven times
higher at sample site M4 than at site M3. A length
frequency analysis for 32 juvenile coho salmon collected
from the Makushin Valley is shown in Figure 1. This
analysis shows a strong maxima in the 50 mm range, and a
weak maxima in the 90-100 mm range which suggests that two
age classes of juvenile cohos may be present in the system.
However, scale analysis (Appendix A) failed to confirm a
definitive second year age class. Scales from fish over
80 mm in length- did not exhibit a growth check, which is
typically caused by slow growth during the winter months.
The absence of a winter check in the larger size range of
fish may indicate either: (1) extraordinary growing
conditions in the Makushin Valley, or (2) very stable water
temperatures which allow fish to remain active and feeding
throughout the winter. One possible explanation for the
second hypothesis is that groundwater contributes
appreciable temperature and flow stability to coho rearing
habitat in the Makushin Valley. Winter stream temperature
data and fish sampling are needed in order to test this
hypothesis.
The time of emergence and outmigration timing is not known
for coho salmon in this area. Because of the extended
spawning period, emergence is likely extended over a long
period of time, perhaps from April - July. Outmigration of
coho smolts may occur during late spring and early summer,
perhaps May - June.
3.1.3 Chum Salmon
Three adult chum salmon were observed at sample site M3.
The fish were lying under a deep overhang cutbank and could
not have been observed from the air. Chum salmon are known
to spawn in streams that have groundwater upwellings.
-9-
for Juvenile Coho Salmon Captured equency Histogram in Makushin Valley (September 2 - 3, 1986). Figure 1. Length Fr
Makushin Valley Coho
LENGTH FREQUENCY Peniegqo sequinu -10-
Although no census of chum salmon has been performed in
Makushin Valley, it is probable that small numbers spawn in
streams below about RM 5. Their spawning timing is believed
to be similar to pink salmon (i.e., July 20 - September 30).
Like pink salmon, chum salmon have no freshwater rearing
phase; the fry/smolts outmigrate to the estuary soon after
hatching. The timing for chum salmon outmigration is not
known for the Makushin Valley but it is likely to be similar
to pink salmon (i.e., February 21 - April 15).
3.1.4 Dolly Varden
Dolly Varden char were found at all sample sites within the
Makushin Valley. The stream appears to have both resident
and anadromous populations. Several large (300-400 mm)
Dolly Varden were captured in bright spawning colors at
sample site M2. The large size is indicative of anadromous
fish. Dolly Varden are fall spawners and migrate upstream
to spawning grounds during August and September. The CPUE
indicates a trend of increasing densities towards the upper
end of the valley. A length frequency analysis for Dolly
Varden (Figure 2) suggests five to seven size classes are
present in the system. However, additional growth data and
scale analysis would be required in order to determine the
age and residence time of Dolly Varden in the Makushin
Valley.
3.2 Driftwood Valley
Streams in Driftwood Valley contained pink and coho salmon
and Dolly Varden char. These species were previously
documented in these streams by ADF&G and Dames & Moore.
Dolly Varden, coho and pink salmon were found at the lower
road crossing (sample site Dl). No fish were found at the
upper road crossing (sample site D2).
3.2.1 Pink Salmon
Pink salmon were observed in small numbers in the main stem
and side tributaries from the mouth up to approximately
RM 2.5. Although some spawning was occurring, most pink
salmon were still. concentrated in schools in the lower 0.5
mile of the main stem. Time did not allow for a detailed
helicopter survey of all waters within the valley. However,
the main stem and the major (east) tributary were surveyed
and an estimated 1000 pink salmon were present in these
streams. Table 3 summarizes six years of escapement records
for adult salmon in Driftwood Valley. The record peak
escapement occurred in 1982 when 6,800 pink salmon were
estimated. The decline in escapement since 1982 follows a
similar trend in the Makushin Valley data. Several pink
salmon were found at sample site Dl in the vicinity of the
-11-
Length Frequency Histogram for Dolly Varden Char Captured in
(September 2 - 3, 1986).
Makushin Valley Dolly Varden
Makushin Valley
Figure 2. ee SN nO a om en i 35 50 65 80 95 110 125 140 155 170 185 200 215 250 245 260 275 290 305 320 335 350 Pesiesqgo sequinu =] 3=
length in 5 mm Increments
Table 3. Pink Salmon Escapement Estimates for Driftwood
Valley.
1/ 2/ Date Count= Observer (s) Remarks—
8-12-61 0.2 Lall & Hennick Two forks
7-19-67 0 Davenport
9-11-72 0.01 Shaul
7-30-80 NA Shaul Nothing
9-03-82 6.8 Shaul Helicopter
+2,000 carcasses survey
9-19-82 1.5 Holmes
+400 carcasses
9-03-86 1.0 Sundberg & Helicopter
Dolezal survey .
3 Estimated escapement in thousands of pink salmon.
Unless otherwise noted, all
fixed-winged aircraft.
NA = Not attempted.
Source: ADF &G, 1979-1985 and this survey.
-13-
counts are from
lower road crossing indicating that spawning likely occurs in this area. The stream in this area is cutting through an old garbage dump left from World War II and numerous metal debris are spread throughout the streambed. This dump should be stabilized or preferably removed to a location out of the floodplain to prevent hazardous materials from entering the stream.
3.2.2 Coho Salmon
Juvenile coho salmon were collected at sample site Dl. The small size of these juveniles (36-38 mm) suggests that they
had recently emerged from a spawning bed close by or had
moved down stream from spawning beds upstream of the site.
No adult coho salmon were seen at the site. However, the substrate appears favorable for spawning and it is likely
that they spawn in this area.
3.2.3 Dolly Varden
Juvenile Dolly Varden char were collected at sample site Dl.
Dames & Moore, found Dolly Varden at the same location
(their sample site DW) in 1982. No fish were collected at sample site D2 above the valley floor. It is probable that Dolly Varden occur in all stream systems within the valley
but upstream migration is limited by physical barriers
(i.e., falls). As in Makushin Valley, both anadromous and
resident forms of Dolly Varden probably occur in Driftwood
Valley, although our survey did not confirm an anadromous
population.
3.3 Glacier Valley
Glacier Valley streams contained pink salmon and Dolly
Varden. Pink salmon were found at sample site G2 and in
clear water side tributaries up to approximately RM 2.5.
Dolly Varden were found at both sampling sites Gl and G2.
3.3.1 Pink Salmon =
Forty-three thousand adult pink salmon were estimated to be
present in Glacier Valley. The major concentration of pink
salmon occurred in the lower 1.5 miles of a clear water
tributary on the east side of the valley. Less than 1,000
occurred in a clear water tributary on the west side of the
valley. Several hundred pink salmon were seen in the
glacially turbid main stem; however, visibility was limited.
Spawning was observed at sample site G2. However,
20,000-30,000 pink salmon were still schooled in the lower
river near the ocean and were moving upstream.
“-14-
Table 4 summarizes eight years of escapement records for
pink salmon in Glacier Valley. The 1986 estimate was the
second highest escapement on record for Glacier Valley and
was the highest pink salmon escapement this year for the
four major stream systems: Makushin, Driftwood, Nateekin,
and Glacier. The highest estimate of 50,000 pink salmon was
recorded in 1984, the parent year for these fish. The
escapement has not significantly declined since 1982 as has
been the trend in both Driftwood and Makushin valleys.
Historically, the east side tributary stream has been the
major spawning area for pink salmon in Glacier Valley and a
major pink salmon producer for Makushin Bay commercial
fisheries.
3.3.2 Dolly Varden
Dolly Varden char were found up to RM 5.3 (sample site Gl)
in both the glacially turbid main stem and clear water
tributaries. Adults were captured in spawning colors at
sample site Gl indicating that spawning by resident Dolly
Varden was occurring at this time. It is likely that Dolly
Varden occur throughout Glacier Valley streams up to the
point where physical barriers (i.e., falls) block upstream
migration.
3.4 Nateekin Valley
The Nateekin Valley is documented to contain pink and coho
salmon and Dolly Varden char. Table 5 summarizes 21 years
of record for salmon escapement estimates in the Nateekin
Valley. The peak spawning escapement occurred in 1982 when
242,000 pink salmon were estimated. The Nateekin River is a
major salmon producer in the Unalaska Bay area. The current
plans for the Unalaska Geothermal Power Project are not
expected to affect the Nateekin Valley. If plans were
changed in a way that would affect this drainage basin,
additional fish habitat studies would be required to define
and protect fish resources.
3.5 Water Quality
Table 6 contains water quality data for the Makushin,
Driftwood and Glacier Valley sampling sites on September 3,
1986. Stream temperatures ranged from a low of 5.9° C in
upper Glacier Creek (sample site Gl) to a high of 8.7° C in
lower Glacier Creek (sample site G3). The temperature in
the east side tributary where most pinks were spawning was
about one degree celsius cooler than the glacially turbid
main stem. Stream temperatures in the Makushin = and
Driftwood valleys ranged from 6.3° C to 7.3° C. There was
no apparent gradient of temperature by elevation in these
-15-
Table 4. Pink Salmon Escapement Estimates for Glacier
Valley.
Date Count+/ Observer (s) Remarks=/
8-21-61 2.0 Lall & Hennick
8-09-62 9 Davenport Glacial
7-26-63 9 Hennick No fish in stream
8-13-64 9 Hennick Stream appears
glacial - no fish
9-09-80 25.0 Shaul All in clear right
tributary
8-12-82 0.3 Malloy East fork only
9-03-82 17.5 Shaul Helcopter survey,
13,700 in east
fork
9-19-82 24.0 Holmes Helicopter survey,
+ 3000 carcasses
7-29-84 NA Malloy Nothing
8-31-84 50.0 Shaul + 3000 pinks at
mouth spawning
in clear :
tributary
9-02-86 43.0 Shaul
1/ Escapement estimates in thousands of pink salmon.
2/ = Unless otherwise noted, all counts are from
fixed-winged aircraft.
NA = Not attempted.
Source: ADF&G 1979-1985 and this survey.
-16-
Table 9.
Date
8-12-61
8-09-62
7-26-63
8-13-64
7-19-67
7-31-67
8-02-68
8-10-68
8-18-68
7-30-69
8-05-69
8-08-70
8-03-71
8-02-72
8-13-72
8-23-72
9-11-72
8-14-73
8-09-74
8-02-75
8-08-75 won os on TP NN NN 7-28-78
8-06-78
Salmon Escapement Estimates for Nateekin River.
Co
25
75.
10.
12.
2.
7.
40. 40.
75.
17.
N
106
14 1
0
0
3
1
3
8
20
20
10. 80.
0.
15
1/ unt—
3
0
-45.0 Oo ooo oO oO oO A
0
-0-
5.0
-025- 0.05
+25 0
75
25
-5-10.0
0
.0-23.0
0 0
2
-0
Observers
Lal] & Hennick
Davenport ~
Hennick
Hennick
Davenport
Wienhold
Davenport
Davenport
Davenport
Davenport
Davenport
Davenport
Davenport
Tamburel 1i
Tamburel1i
Davenport
Shaul
Davenport
Davenport
Davenport
Davenport
Davenport
Tate
Nelson
Griffin
-17-
Results=/
Good escapement
Large schools of pinks
All fish in first two miles of
stream
Boat fishing along beach with
skiff, moderate size schools
Most all in first mile
Estimate
Fish along beach, fish fresh
and moving up, none above
4 miles
Too turbulent to fly
Most in first 2.5 miles
Scattered up 5 miles, most .5
to 1 mile up
Just entered river, moved
upstream fast
Just inside mouth of river
Scattered up 2 miles, 4 skiffs
in creek with one seine aboard
Pinks spawning mostly in lower
portion, a few carcasses
Estimate
Most in lower end, additional
pinks at mouth
Fish up 3 miles, most in lower
1 mile
Fish slowly moving up in lower
1.5 mi
Additional 2,000 pinks at mouth
Includes many carcasses,
distribution heavy in 2/3,
moderate in upper 1/3
Scattered schools in lower 1/2
mile, additional 300 at mouth
Count might be conservative,
50 additional at mouth
Table 5 continued.
Date
8-23-78
2/
Count//
40.0-50.0
122.0
90.0
8.0 12.0-15.0
75. 132. 131.
69. oooo°o 50. 48.
22.
30. 103. 222.
243.
150. 40 ooo°o°o Oo oom on wo . oo °o => °o NA
78.0
151.0 145.0
12.0
11.5
+ 200 coho
NA = Not available.
Source: ADF&G@ 1979-1985.
Observers
Nelson
Shaul
Shaul
Shaul
Shaul
Shaul
“Shaul
Shaul
Shaul
Shaul
Shaul
Malloy
Shaul
Griffin
Griffin
Shaul
Malloy
Tyler & Gallis
Vinyard
Shaul
Griffin
Malloy
Shaul
Shaul
Griffen
Shaul
-18-
Results</
Estimate from foot survey,
pinks concentrated at mouth up
to hole by hill approximately
1 mile up, bright pinks in
lower stream
Most in lower end, additional
12,000 at mouth
Some still schooled
Lower 2 miles
More in lower 200-300 yards
Looks good
Only surveyed lower 2 miles,
probably 30,000 above, many
schooled
Very murky, count low
No boats
Probably another 10,000 above
where survey ended
All spawning
Looks tremendous
Foot survey
Foot survey, didn't count pinks
200-300 pinks at mouth, but
stream too murky
Many in lower end, looks good
very poor
Escapement estimates in thousands of pink salmon.
Unless otherwise noted, all counts are from fixed-wing aircraft.
Table 6. Water Quality at Fish Sampling Sites in Makushin,
Driftwood, and Glacier Valleys (September 3, 1986).
Dissolved
Sample Temperature Oxygen Conductivity
Site (°C) pH (mg/1) (umho/cm*)
Makushin
M1 7k 6.5 10.6 77
M2 - - - -
M3 6.3 5.3 10.8 102
M4 7.3 5.8 935 193
Driftwood
D1 6.7 6.1 t2—1 39
D2 6.8 6.4 11.3 73
Glacier
Gl 5.9 6.6 22-5 60
G2 7.8 5.9 10.9 80
@32/ rs 6.0 cia 140
27. No fish were sampled at this site.
-19-
valleys. Two sample areas where salmon were spawning varied
in temperature by one degree celsius.
The pH for all sample sites was slightly acidic ranging from
5.3 to 6.6. Dissolved oxygen (DO) for all sampling sites
was below 100 percent saturation levels. The lowest DO
occurred at site M4. Conductivity ranged from a low of 39
umho/cm” at the, lower Driftwood Valley site (Dl) to a high
of 193 umho/cm” at the lower Makushin Valley site (M4).
Site M4 had visible orange colored staining in the water and
on the streambed, presumably from mineralized iron. The
high conductivity and low DO at sample site M4 supports
speculation that this tributary is largely groundwater fed.
Conductivity decreased with higher elevations in both the
Makushin and Glacier valleys.
3.6 Human Use
Aquatic habitats within the Makushin, Glacier, Driftwood,
and Nateekin valleys produce fish resources of importance to
commercial, sport, and subsistence fisheries on Unalaska
Island. Unalaska Island is the major salmon producing area
in the Aleutian Islands (ADF&G, 1982). Table 7 presents the
past eight years of commercial pink and coho salmon catches
for two ADF&G statistical areas on Unalaska Island, Unalaska
Bay and Makushin Bay. ADF&G catch statistics do not break
down catches by individual streams. Unalaska Bay catch
figures contain production from both Makushin and Nateekin
valley streams which are both felt to contribute
significantly to statistical area 302-31. Broad Bay, at the
mouth of the Makushin River supports three to four seine
boats during an average even-year pink salmon fishery.
During an exceptionally large run in 1982, up to twelve
seining vessels were observed fishing in Broad Bay (Arnie
Shaul, pers. comm.). Makushin Bay catch figures contain
Glacier Valley streams which are felt to produce
approximately 50 percent of the pink salmon catch in
statistical area 302-24. The low catch in 1986 has been
attributed to a poor even-year return of pink salmon to
Unalaska Island streams. The reason for the poor return is
not known but may include poor ocean survival for the
1984-85 cohort.
In addition to commercial fisheries, subsistence and sport
fisheries occur in Makushin and Nateekin valley streams.
Coho salmon are the principal target species for subsistence
and sport fisheries although Dolly Varden are also taken.
Because of difficult access, the subsistence and sport catch
of coho salmon in the Makushin River is low compared to
catches from streams along the Unalaska-Dutch Harbor road
system. The number of fishing parties using the Makushin
Valley area on any day during the peak of the coho run is
-20-
Table 7. Pink and Coho Salmon Commercial Catch for Unalaska
Bay and Makushin Bay Statistical Areas, 1979-86.
Catch (in numbers of fish)
Year Areat/ Pink Coho
1979 302-31 511,982 0
302-24 . 25,004 0
1980 302-31 554,049 1
302-24 2,028,421 1
1981 302-31 237,630 188 302-24 65,152 0
1982 302-31 551,419 28 302-24 767,790 0
1983 302-31 NA NA 302-24 1,890 : 0
1984 302-31 914,310 0 302-24 1,166,605 23
1985 302-31 0 0 302-24 0- 0
2/ 302-31 20,709 10 1966 302-24 17,494 6
1/ = 302-31 includes all of Unalaska Bay.
302-24 includes all of Makushin Bay.
z Preliminary data.
NA = Not Available.
Source: ADF&G 1979-1985, 1986 data from Arnie Shaul, pers.
comm.
-21-
generally less than three (Ken Griffin, pers. comm.). There
is no known subsistence or sport fishery in either Driftwood
or Glacier valleys although fishing may occasionally occur
in these streams. Access to these areas from Unalaska-Dutch
Harbor is significantly more difficult than the Makushin
Valley area.
Hunting and trapping also occur within the project area.
Waterfowl including mallard and pintail are hunted during
the fall in the side sloughs and wetlands along the Makushin
River. Emperor geese are taken along the beaches of Broad
Bay. Ptarmigan are hunted during winter along the side
slopes of the Makushin Valley. Red fox are hunted and
trapped in both Makushin and Driftwood valleys. Razor clams
attract clam diggers from Unalaska-Dutch Harbor to Broad Bay
beaches during spring tides. Broad Bay contains the only
significant razor clam resource in Unalaska Bay.
At the present time, overall human use levels in Makushin
Valley could be described as low, primarily because of
difficult access. Improved access would more than likely
increase the human use of the area.
-22-
PART II
POTENTIAL EFFECTS OF UNALASKA GEOTHERMAL POWER
PROJECT ON FISH AND WILDLIFE
II-1.0 Executive Summary
The ADF&G, Habitat Division conducted a preliminary
evaluation on the potential effects of the proposed Unalaska
Geothermal Power Project on the fish and wildlife resources
on Unalaska Island. This evaluation was conducted by
synthesizing information from: published literature,
federal and state water quality standards, and contacts with
appropriate agency personnel. For purposes of the analysis,
it was assumed that a 12 MW generating facility will be
constructed near Fox Canyon Creek. Operation of the
facility would require construction of several miles of new
road, the upgrading of an existing road, and_ the
installation of a buried transmission line. Geothermal
effluent was also projected to be discharged into Fox Canyon
Creek at a rate of 5 cfs.
Although the analysis is incomplete, it appears that the
potential effects on surface waters pose the greatest
environmental concern, with direct physical effects posing
significant, but lesser concerns. Potential environmental
effects resulting from noise, air pollution, and increased
human presence are, at this point, judged to be of least
concern.
In terms of water quality variables, the potential for
increased water temperatures to reduce the incubation period
of salmonids is a major concern. Even a one degree rise of
water temperature over the incubation period can result in
accelerating the development of salmonids by approximately
one month. If fry emerge prematurely, availability of food
may be limited resulting in significantly reduced survival
rates. Two other potentially harmful components, arsenic
and hydrogen sulfide, are also of major concern, because
even after considering a dilution rate of five to one they
exceed current U.S. Environmental Protection Agency (EPA)
water quality standards by 12 and 170 times, respectively.
Further investigation and analyses are required to determine
the potential for harmful effects resulting from increases
in total gas pressure and increased concentrations of lead,
mercury, and cadmium.
Based on the analysis to date, the most environmentally
preferable approach for mitigating potential surface water
impacts is to reinject the geothermal effluent into a
hydrologically isolated underground formation. Other
-23-
alternatives to mitigate potential surface water effects
could include: (1) piping the geothermal effluent to the
coast where it could be discharged into the ocean, or
(2) constructing cooling towers, chemical treatment
facilities, and possibly gas-stripping towers to reduce
effluent temperatures and remove hazardous contaminants from
the geothermal effluent. The first alternative would
potentially make the heat from the effluent available for
other projects including aquaculture and agriculture.
II-2.0 Methods
Four sources of information are being used to evaluate the
Unalaska Geothermal Power Project: (1) a literature review
of potential geothermal development impacts, (2) a
description of fish and wildlife resources in the affected
area, (3) the chemical composition of the geothermal
reservoir fluid, and (4) an assumed project scenario.
Specific methods used to collect each of these sources of
information are summarized below.
Literature was obtained from ADF&G's Habitat Division
Library in Anchorage, and through a computer-assisted search
of the DIALOG data-base. As a result of the DIALOG search,
147 literature items were requested from other libraries.
Also, a letter of inquiry was sent to Dr. Don Forsythe of
the Department of Scientific and Industrial Research in
Taupo, New Zealand requesting information related to the
Wairakei and proposed Ngawha geothermal projects undertaken
in---that*> country. Personal contacts were made with
Mr. Haukor Tomasson, Dr. Hakon Adolsteinsson, and Mr. Ulfar
Antonsson to discuss environmental effects of geothermal
power plants in Iceland. Also the Hitaveita Sudurnes, a
geothermal power and heat cogeneration project was visited
in Svartsengi, Iceland. Additional requests for literature
were made to several government agencies in Alaska including
the EPA and the U.S. Fish and Wildlife Service.
A description of the aquatic resources in the Unalaska area
was primarily derived from Part I of this report.
Background water quality data for the Makushin Valley area
was obtained from the Department of Natural Resources' (DNR)
Engineering Geology Technical Feasibility Study (DNR, 1986).
Composition of the geothermal effluent was obtained from the
1985 Republic Geothermal Inc. Phase III Final Report. The
project scenario was developed through personal contact with
David Denig-Chakroff, APA. Additional technical information
was obtained from Thomas Krzewinski, Dames & Moore; Don
Michels formerly with Republic Geothermal Inc.; and Stan
Carrick, Division of Geology and Mining, DNR.
-24-
II-3.0 Development Scenario
Because the development scenario for the Unalaska Geothermal
Power Project is currently evolving under the APA feasibility study, we considered several scenarios for the plant site, road access, and waste water disposal. One
development scenario used in this analysis calls for a 12
megawatt (MW) generating facility to be constructed on the
bench near the existing geothermal resource well, ST-1
(Plate 2). Access to the site would be gained by repairing
and upgrading the existing road from Driftwood Bay. An
alternate road access would parallel the transmission line
in the Makushin Valley. Final access would either be via a
road constructed across Fox Canyon or by helicopter from a
road accessible staging area. An alternative scenario would
place the generation facility on the north side of Fox
Canyon Creek. This configuration would eliminate the need
to develop road access across Fox Canyon but would require
directional drilling in order to reach the reservoir. The
transmission line would be buried from the generation
facility to Broad Bay where it would go by submarine cable
to Unalaska - Dutch Harbor. Waste geothermal water would be
discharged into Fox Canyon Creek in the upper Makushin
Valley at a rate of 5 cfs. An alternative disposal scenario
would reinject the waste geothermal water into a
hydrologically isolated formation on the north side of Fox
Canyon Creek or pipe the waste geothermal water to Driftwood
Bay for ocean disposal.
II-4.0 Potential Effects
Based upon our initial literature review, we have identified
eight potential effects of geothermal energy development on
fish and wildlife resources. These effects include:
(1) direct physical (construction) effects on habitat,
(2) erosion, (3) surface water effects, (4) groundwater
effects, (5) air pollution, (6) noise, (7) human presence,
and (8) accidents. Additional literature review is
currently ongoing to obtain more specific information on
these potential geothermal development effects. Following
is a summary of the information we have assimilated to date.
4.1 Direct Physical Effects
Direct physical effects on habitat would primarily result
from site clearing activities (e.g., power plant, staging
area, road and transmission line right-of-way (ROW)) during
the construction phase of the project. Site clearing for
the power plant and staging areas is not believed to present
a significant impact for fish and wildlife habitat at this
time because: (1) the area to be cleared is relatively
small compared to the habitat available to fox, ground
-25-
squirrels, and birds that inhabit the area; (2) no unique
aquatic or wetland habitats occur at the plant site; and
(3) no sensitive or critical habitats are believed to occur
at the plant site. However, the construction of roads and
burial of the transmission line is likely to present
significant potential impacts to fish and wildlife habitats.
These activities will disturb significant amounts of acreage
and may result in several stream crossings, substantial
erosion, and alteration of surface water drainage and
groundwater flow patterns.
4.1.1 Stream Crossings
The impact from stream crossings is a concern, because it
can directly affect the migration of fish as well as the
quality of spawning and rearing habitats. Where stream
crossings must be located within spawning areas, it is
important to minimize alteration of streambed materials,
flow characteristics, and water levels in order to maintain
conditions that provide for successful spawning and
incubation. In rearing areas, the goal is to avoid removing
important cutbanks and streamside vegetation which supply
protective cover for juvenile salmonids. It is also
important to ensure that water velocities within stream
crossings are low enough to allow for unrestricted upstream
migration by fish. Culverts which accelerate stream flows
above the swimming capabilities of fish or destabilize the
stream bed causing scour and perching can block fish
migration.
Mitigative measures for minimizing stream crossing impacts
are similar for both spawning and rearing areas. Clear span
bridges are the preferred stream crossing structure in
either of these areas. Open bottom culvert designs (e.g.,
bottomless arch and box) may be approved where they do not
constrict the active stream channel or lead to unacceptable
changes in the stream bed. Round or elliptical culverts are
generally not approvable in spawning areas and significant
rearing areas because they can produce undesirable changes
in the channel bed and flow characteristics. ADF&G has
developed culvert installation guidelines that should be
followed to minimize impacts from culverted crossings in
fish habitat (Appendix E).
Available information for the Makushin and Driftwood valleys
indicates that salmon spawning and rearing habitat are
coincident in both streams and that cutbanks provide
important rearing habitat. Therefore, road crossings within
portions of Makushin valley streams including side
tributaries below RM 5.6 and portions of Driftwood Valley
streams including side tributaries below RM 3_ should
incorporate either bridge or open bottom culvert designs to
-26-
Maintain the existing bed and bank morphology. Above the
upper limit of salmon habitat and within portions of streams
that support Dolly Varden, round or elliptical (CMP)
culverts would be approvable. However, bridges or open
bottom culverts are preferable below the Makushin River
Canyon (RM 7.2) where Dolly Varden spawning was observed and
potential salmon spawning habitat occurs. Where road
construction or installation of the transmission line is
required in spawning areas, the instream work should be
timed to avoid disturbing fish eggs and alevins which may be
present in spawning beds (i.e., the instream construction
window is July 1-20). Additional precautions must be taken
to minimize sedimentation downstream and to restore the
streambed to a stable and productive condition when the
installation is completed.
4.1.2 Surface Drainage Patterns
Alterations to surface drainage patterns are of concern
because they can adversely affect wetland areas, create
impoundments in areas containing springs and seeps, and
increase sediment transport into streams. General
mitigative measures to minimize impacts from alteration of
surface drainage patterns include: (1) minimizing
excavation, filling, grading, channelization, or removal of
vegetation in wetlands, such as those located in the lower
Makushin Valley; (2) grading construction areas to ensure
that the flow of surface waters is along natural drainage
courses; (3) providing adequate cross drainage especially in
areas containing springs or seeps; and (4) directing run-off
waters with high sediment loads thru vegetated areas to
allow filtration and settling of suspended solids prior to
their discharge into streams.
There may be potential for improving waterfowl habitat in
the Makushin Valley through the creation of additional
ponds. However, this type of mitigation would need to be
carefully planned to be compatible with fish resources
(i.e., to ensure that needed flows were not disrupted).
4.2 Erosion
Erosion of land surfaces in the project area may be caused
by wind, water, gravity, and freeze-thaw. Disturbed land
surfaces, including cuts and fills, work pads, and roads,
are particularly vulnerable to erosion. The volcanic soils,
steep slopes, numerous springs, heavy rainfall and high
winds in the project area may compound erosion problems if
they are not carefully considered when facilities are
designed and constructed.
-27-
Erosion control will be required to maintain the stability of permanent structures placed in aquatic habitats and to protect disturbed lands and earth structures that could introduce’ sediments into important aquatic habitats. Streams that are particularly sensitive to erosion include clear water tributaries in the Makushin Valley. Engineering standards applied to structures placed in flood plains should incorporate erosion control measures including scour protection, drainage, and filter blankets to ensure that they remain stable under extreme flooding conditions. An erosion control plan including measures to capture and treat sediment laden water and to stabilize and revegetate disturbed soils, particularly adjacent to aquatic habitats should also be developed before the project is constructed. The APA Best Management Practices Manual for Erosion and Sedimentation Control provides a good basis for developing an erosion control plan for the project.
4.3 Surface Water Effects
Surface water effects on aquatic habitats may occur from
direct sources, such as the discharge of geothermal fluids
into surface waters, and indirect sources, such as drainage from the plant, roads, and staging areas, including hazardous materials spills. The indirect sources can be controlled to minimize impacts by incorporating procedures ‘discussed under the Erosion and Accident sections of this report. Controlling direct sources to minimize adverse impacts may be more complex if geothermal effluents are discharged to surface waters.
We are currently investigating the potential effects to fishery resources from discharging geothermal effluent into the Makushin River. Based upon our initial review, we have identified the following geothermal effluent components which may present a significant threat to Makushin River fish populations: (1) temperature, (2) arsenic, (3) hydrogen sulfide, (4) supersaturated gases, (5) lead, (6) mercury, and (7) cadmium. Each of these components are briefly discussed below.
In terms of mitigating potential surface water effects, our preliminary analysis clearly indicates that reinjecting the geothermal effluent into a hydrologically isolated formation
would be the most environmentally preferable approach. Other alternatives might include: piping the geothermal
effluent to the coast where it could be discharged into the
ocean, or constructing cooling towers, chemical treatment facilities, and possibly gas stripping towers to reduce
effluent temperatures and remove hazardous contaminants from
the geothermal effluent.
-28-
4.3.1 Temperature
Temperature is a component of paramount concern because fish
and aquatic life are . temperature dependent. Water
temperature requirements play an important role in the
salmon life cycle and encompass an extremely wide range of
temperatures, 0 to 25° C. The ability to survive within
this temperature range and specific requirements, however,
vary by: life stage (i.e., egg, alevin, juvenile, and
adult), the temperature to which the fish have been
acclimated, and adaptions that specific stocks have made
over the course of their evolutionary history. The period
of time needed for salmon eggs to incubate and hatch is
dependent upon the stream temperature. Normally, 850-950
Temperature Units (TU) are required for salmon egg and
alevin incubation until the fry emerge from the gravel (Each
°c of the average daily water temperature equals one TU.
TUs are accumulated daily). Even a one degree rise of water
temperature in a spawning bed over the incubation period can
result in significantly accelerated development. For
example, at an average daily stream temperature of 5° C
(41° F) the development period for pink salmon is about 190
days. At 6° C (42.8° F), the development period is 158
days, a difference of 32 days.
Various stocks of wild salmon have evolved to take advantage
of optimum conditions in the environment where they spawn,
rear, and feed. Timing changes in one portion of the life
cycle can significantly affect other portions of the life
cycle. In pink salmon, the fry outmigrate to the estuary
shortly after emerging from the gravel. Through years of
evolution within a particular fish stock, the emergence is
timed to take advantage of seasonal plankton blooms which
provide the necessary food when the smolts reach the
estuary. For example, if emergence is accelerated by four
weeks, fry could conceivably arrive at the estuary during a
low level in the plankton cycle and the smolts could
subsequently perish.
Juvenile salmon are also very sensitive to rapid temperature
changes, such as might occur if a geothermal plant
discharging heated water were shut-down for repairs and then
restarted. Temperature shock can be induced with
instantaneous water temperature changes of as little as two
degrees celsius. The rate of change of temperature
determines the degree of temperature shock. Generally
salmon can tolerate water temperatures up to about 16° C
(61° F) without suffering ill effects so long as the
temperature changes are gradual. The current water quality
standards for the State of Alaska identify two measures of
water temperature for freshwater environments: (1) maximum
water temperatures, and (2) weekly average temperatures
-29-
(DEC, 1984). Twenty degrees celcius is the maximum
allowable water temperature, not to be exceeded at any time.
Fifteen degrees celcius is identified as the maximum
temperature for fish migration routes and rearing areas, and
13° C for spawning and incubation areas (egg and fry).
Weekly average temperature criteria are also applied to
Alaska waters and are based on site-specific requirements
needed to preserve normal species diversity or to prevent
nuisance organisms. To date the site-specific requirements
for the affected area have not been established. In the
final report, the State of Alaska water temperature criteria
will be evaluated in light of current EPA criteria and
recommendations specific to the proposed project will be
presented.
4.3.2 Arsenic
Arsenic is identified as one of EPA's priority pollutants
and is highly toxic to aquatic fauna. Arsenic
concentrations in the Makushin geothermal effluent were
reported to be 11.2 mg/L which exceeds EPA's’ chronic
exposure criterion for freshwater organisms (190 ug/L) by 59
times.
Under normal practices, EPA applies water quality criteria
to end-of-pipe discharges, however upon request a mixing
zone variance may be incorporated into a National Pollution
Discharge Elimination System (NPDES) permit. Under this
approach, EPA would apply the national water quality
exposure criteria at the end of the mixing zone. The length
or size of this mixing zone is generally determined by a
computer generated discharge plume model (Dan Robison, pers.
comm.) . We do not anticipate being able to accurately
determine how far downstream this mixing zone might extend.
However, for preliminary planning purposes, we _ have
evaluated two mixing zone scenarios. The first would only
include the Fox Canyon Creek drainage which has an
approximate low winter flow of 10 cfs (Stan Carrick, pers.
comm.). The second scenario would extend the mixing zone
downstream to include the junction of the Makushin River and
Fox Canyon Creek, which would produce a low winter flow rate
of approximately 25 cfs. If we assume a 5 cfs geothermal
effluent discharge rate, these two mixing zone scenarios
could provide a two-fold or five-fold dilution factor,
respectively. Both of these potential dilution rates are
clearly insufficient to meet water quality standards for
arsenic concentrations.
Treatment technologies for aqueous arsenic removal fall into
three major categories: ion exchange, activated alumina
absorption, and precipitation or absorption by metal
hydroxides (prominently ferric hydroxide). Ferric hydroxide
-30-
floc appears to be the most cost effective and efficient
method of arsenic removal (Krapf, 1983).
4.3.3 Hydrogen Sulfide
Hydrogen sulfide a soluble, highly poisonous,
gaseous compound exniticing a characteristic odor of rotten
eggs. The degree of hazard exhibited by hydrogen sulfide to
aquatic fauna is dependent on the pH, dissolved oxygen, and
temperature. The EPA has established an exposure criterion
of 2 ug/L undissociated H,S for both fresh and marine
waters. The geothermal effluent is reported to contain 1.7
mg/L of H4S which exceeds the EPA criterion by 850 times.
However, this concentration of H,S will rapidly decline once
the geothermal water is discharged into freshwater streams.
To assist in determining the persistence of hydrogen sulfide
after discharge, Don Michels, formerly with Republic
Geothermal Inc., suggested modelling the chemical reactivity
and gas equilibrium shift of H,S under the expected
conditions to determine its approximate half-life.
Discussions concerning this approach are currently on-going.
Preliminary investigations indicate that gas stripping
towers or possibly cooling towers could remove hydrogen
sulfide from the geothermal effluent prior to discharge.
Additional research will be conducted to more fully evaluate
the potential problems associated with the high hydrogen
sulfide concentrations.
4.3.4 Supersaturated Gases
Only preliminary investigations have been made on the
potential for supersaturated gas conditions to result from
discharging geothermal effluent into local streams. Two
factors must be assessed when evaluating this potential
problem. The first factor involves the level of gas
saturation and the composition of the gases in the effluent
proposed for discharge. Geothermal fluids are commonly
supersaturated with total dissolved gases, however, there
appears to be insufficient data with which to determine the
level of gas saturation in the Makushin geothermal fluid.
The second factor is that temperature indirectly affects
dissolved gas concentrations by changing the solubilities of
dissolved gases. Because gas solubility decreases with an
increase in water temperature, the heating of cold water
will result in an increase in the total dissolved gas
concentration. Since Makushin Valley streams have high
levels of gas saturation (DNR, 1986), heating of these
waters from geothermal discharge may result in aé gas
supersaturated condition.
-31-
Supersaturation can cause gas bubble disease in a wide
variety of fish and invertebrate species. The disease is
the result of a noninfectious, physically induced process
where gases may form emboli in the blood resulting in
blockage of blood vessels, tissue damage, and eventual death
(Bouck 1980). Susceptibility to the disease varies with
species, life-stage, size of fish, duration of exposure, and
the ability of the fish to change water depths. In general,
alevin and fry stages appear to be relatively more sensitive
to the disease than the egg or adult stages (Weitkemp and
Katz, 1980). Gas bubble disease has been observed in
hatchery alevins and fry at total gas pressures in the range
of 101-105 percent, resulting in the general recommendation
that total dissolved gas pressure in hatchery water supplies
should not exceed 103 percent (SIGMA Environmental
Consultants LTD 1983).
Initial review and discussions suggest that gas saturation
problems could be mitigated through the installation of gas
stripping towers or possibly water cooling towers.
Additional research will be conducted to assess the
potential for supersaturated gas conditions to occur and to
evaluate possible mitigative measures.
4.3.5 Lead, Mercury, and Cadmium
Lead, mercury, and cadmium are also classified as priority
pollutants by EPA, and are of particular concern due to
their extremely high toxicity and bioconcentration
characteristics. The EPA freshwater four-day average
exposure criterion for lead, mercury, and cadmium is 3.2
ug/L, 0.012 ug/L, and 9.3 ug/L, respectively. We have been
unable to determine whether the concentration of these
elements in the geothermal effluent exceeds the EPA exposure
criteria, because the detection limits in Republic
Geothermal's water quality analyses exceed the respective
EPA criteria. The detection limits for lead, mercury, and
cadmium were 244 ug/L, 0.2 ug/L, and 61 ug/L, which exceed
the respective EPA criterion by approximately 76, 17, and
seven-times. Additional water chemistry tests for these
elements will need to be conducted to determine the
potential threat of these compounds to fish populations and
to meet permitting requirements.
4.4 Ground Water Effects
In terms of aquatic life, groundwater effects are similar to
surface water effects except they are more diffused. Some
of the spawning areas in the Makushin, Driftwood, and
Glacier valleys (i.e., the clear water tributaries) appear
to be groundwater fed. Contamination of groundwater in the
reservoir area could eventually resurface in aquatic
39-
habitats downstream. Of perhaps greater concern, roads or a
buried transmission line could disrupt groundwater flow into
important spawning and rearing habitats by intercepting,
rechanneling, or contaminating springs. These spring fed
streams appear to be important to fish populations in the
area both as spawning and rearing habitats. Formation of
aufeis by intercepting groundwater and exposing it to
surface cooling (e.g., along trenches and road cuts) may
also disrupt groundwater movement.
4.5 Air Pollution
Geothermal plants can emit gases and vapors containing
carbon dioxide, hydrogen, methane, hydrogen sulfide,
ammonia, carbon monoxide, hydrogen flouride, hydrogen
bromate, mercury, radium, radon and arsenic (Woodward Clyde
Consultants, 1978). The condensed components of air
emissions enter the environment through runoff and should be
considered when determining surface water effects. Fall-out
of components in air emissions can also affect vegetation
and soils, particularly in the local area. However, the
high precipitation in the plant area would probably help to
dilute the pollutants and slow their buildup in the soil.
At this time, it is not felt that air pollution from
construction or operation of the plant would pose a
significant impact to fish and wildlife.
4.6 Noise
Geothermal power plants emit an intense level of noise,
particularly in the higher audible frequencies. Initially,
noise could be a factor in affecting the distribution of
wildlife (e.g., ground squirrels, fox, birds) in close
proximity to the plant. However, it is expected that most
species would become habituated to certain types of noise
(for example, fox frequent many industrial sites in Alaska)
and in time it may not play a significant factor in their
distribution. Noise levels also decline exponentially with
distance. Because no particularly sensitive wildlife
habitat has been identified in the plant area, noise is not
expected to create a significant impact on wildlife.
4.7 Human Presence
Increased human presence in the Makushin and Driftwood
valleys is expected to affect fish and wildlife because
human presence is currently limited by difficult access.
Access improvements will allow more people to hunt, trap,
and fish in the area.
Presumably the greatest influx of people will occur during
the construction phase of the project. Many construction
-33-
workers will undoubtedly participate in recreational fishing
for salmon and Dolly Varden. Workers may also engage in
waterfowl and ptarmigan hunting and shooting or trapping
fox. Harvest activities are likely to decline as
construction workers leave the area.
During the operation of the project, it is likely that
Maintenance and operation personnel will continue to hunt,
trap, and fish in the area. Depending on access
improvements (e.g., a road from Broad Bay), the use of the
area by Unalaska - Dutch Harbor residents will also likely
increase.
It is not expected that increased harvest either during the
construction or operation phase of the project will deplete
any fish or wildlife species in the area. However,
additional management attention by ADF&G may be needed to
ensure that harvest restrictions are adequate to protect
sustainable populations of fish and wildlife.
Increased -human presence both within and outside of the
project area may also cause some disturbances of sensitive
fish and wildlife (e.g., waterfowl, bald eagles, hawks,
falcons, spawning salmon). These disturbances would be most
frequent during the construction phase of the project as a
result of increased aircraft traffic, equipment operation,
and workers on the ground. However, the disturbances should
be temporary and should not be expected to significantly
affect fish or wildlife use of the area. Areas of
_particular sensitivity such as raptor nests and spawning
areas should be identified and posted to protect them from
disturbance. Some wildlife in this area (e.g., fox, ravens,
magpies, gulls) may be attracted to humans in order to
obtain food. Fortunately, fox in this area are not believed
to be infected by rabies. Proper disposal of garbage and an
environmental training program for workers could reduce the
overall impact of human presence on fish and wildlife in the
area.
4.8 Accidents
Accidents associated with this type of project which could
significantly impact fish, wildlife, and aquatic habitats
include: (1) a catastrophic spill of fuel or other toxic
substance which enters marine waters or a stream; (2) a
blowout of a well or failure of control systems that
releases large volumes of geothermal fluids into a stream,
or (3) a landslide that introduces a large quantity of
sediment into important fish habitat. The handling and
storage of all significant quantities of fuels, explosives,
and toxic substances should be covered by a hazardous
materials plan. The plan should address the siting of bulk
-34-
storage facilities, procedures for handling hazardous
materials, and contingency plans for reporting, containing,
and cleaning up spills. The APA Best Management Practices
Manual for Fuel and Hazardous Materials provides a good
basis for the preparation of such a plan.
Blowouts of geothermal wells are infrequent but can occur
when unexpected formation pressures or faults are
encountered in drilling or when equipment such as mud
systems or blowout preventors malfunction. Other equipment
and systems malfunctions that may occur during operation of
the project include broken pipes or valves, containment
failure of a reservoir such as a cooling pond, pump
failures, and breakdowns in the water treatment system. The
type of impacts to fish and wildlife would depend upon the
severity of the accident, but would include those described
previously under surface water and groundwater effects. The
chances of accidents of this type occurring can be minimized
by employing experienced well drillers and competent
operations and maintenance personnel for the project.
Contingency plans (e.g., blowout prevention plan) and
Management procedures should be in place to reduce risks and
solve problems before they develop into accidents.
Landslides may occur as a result of the steep slopes and
unstable soils in the area (DNR, 1986). The clear water
tributaries and springs in the Makushin Valley are
particularly vulnerable to impacts from landslides and other
slope failures. These impacts are discussed under erosion
effects. Accidents of this type can be minimized by routing
the road and transmission line ROW to avoid areas of slope
instability as well as incorporating high levels of
engineering and construction standards in the project.
II-5.0 Permitting Requirements
Based upon our preliminary analysis, it appears that the
environmental protection permits identified in Table 8 will
be required for the project to be constructed and operated.
This list is preliminary and, other than the ADF&G Fish
Habitat Permit, does not officially represent any other
agency's permit jurisdiction. Individual agencies should be
contacted to determine their permitting authorities and
requirements.
-35-
Table 8. List of Environmental Permits That May Be Required for
Construction and Operation of the Unalaska Geothermal Power
Project.
Federal Agency
U.S. Environmental
Protection Agency
U.S. Army Corps
of Engineers
U.S. Fish and
Wildlife Service
State Agency
Office of
Management
and Budget*
Department of
Fish and Game
Permit
NPDES
New Source
Performance
Standards
404 Wetlands
Protection
Section 10
Navigable
Waters
Refuge Permit
Permit
Coastal
Consistency
Determination
Fish Habitat
Permit
-36-
Activity
Wastewater Discharge
Air Emissions
Construction of
roads, fills, and
transmission line in
wetlands and streams
Construction of
docks, landings, and
submarine cable in
navigable (marine)
waters
Any surface
disturbing
activities on Alaska
Maritime Refuge
lands
Activity
Consistency of the
project with
Standards of the
Alaska Coastal
Management Program
Construction
activities
(e.g., stream
crossings, bank
stabilization,
transmission line)
and equipment
fording in fish
streams
Table 8 continued.
State Agency
Department of
Environmental
Conservation
" " "
" " "
Permit
Air Quality
Control
Wastewater
Discharge
Hazardous
Materials
Solid Waste
Activity
Air emissions
Geothermal Effluent
and Sewage Disposal
Fuel and Other
Hazardous Materials
Storage and Handling
Disposal of garbage,
construction wastes,
and drilling muds
Department of Tidelands Placement of docks,
Natural barge landings, and
Resources submarine cable on
tide and submerged
lands
: i tt Water Withdrawal and use
Appropriation of surface or
groundwater
* Because this project is located within the coastal zone, the
Division of Governmental Coordination within OMB will be the
coordinating agency for all state permits.
-37-
REFERENCES CITED
Alaska Department of Fish and Game (ADF&G).
Finfisheries Annual Report,
1979-1985.
Islands Areas 1979-1985.
Alaska Peninsula-Aleutians
State of Alaska, Department
of Fish and Game Commercial Fishery Division.
Alaska.
Juneau,
ADF&G. 1982. Aleutians
Study:
Islands Salmon Stock Assessment
Special Report to the Alaska Board of Fishery.
Patrick B. Holmes, auth. State of Alaska, Department of
Fish and Game, Anchorage, Alaska. 83 pages.
ADF&G. 1985. Alaska Habitat Management Guide,
Region, Volume I:
Southwest
Fish and Wildlife Life Histories,
Habitat Requirements, Distribution, and Abundance, 545
pages; Volume II: Human Use of Fish and Wildlife, 639
pages; Map Atlas, 66 maps. State of Alaska, Department
of Fish and Game, Habitat Division. Juneau, Alaska.
Bouck, G.R. 1980. Etiology of gas bubble disease. Trans.
Am. Fish. Soc., 109:703-707.
Carrick, S. 1986. Personal Communication. ADNR, Division
of Geological and Geophysical Surveys, Eagle River,
Alaska.
Dames and Moore. 1983. 1982 Environmental Baseline Data
Collection Program Final Report. Prepared for Republic
Geothermal Inc., Alaska Power Authority, Anchorage,
Alaska. 55 pages.
Denig-Chakroff, D. 1986. Personal Communication. Alaska
Power Authority. Anchorage, Alaska.
Department of Environmental Conservation (DEC).
Chapter 70
1984,
Water Quality Standards.
70.020(c) (5). ,
18 AAC
Department of Natural Resources (DNR). 1986. Engineering
Geology Technical Feasibility Study Makushin Geothermal
Power Project Unalaska, Alaska. Vol. I.
File 86-60. Prepared for
Public - Data
Anchorage, Alaska.
Alaska Power Authority,
Griffin, K. 1986. Personal Communication. ADF&G. Commercial
Fisheries Division. Unalaska, Alaska.
Krapf, N.E. 1983. Commercial Scale Removal of Arsenite,
Arsenate, and Methane Arsonate from Ground and Surface
-38-
Water. In: Arsenic: Industrial, Biomedical,
Environmental Perspectives, W.H. Lederer and R.J.
Fensterheim, eds., Van Nostrand Reihold Co. Inc. New
York, N.Y. pages 269-281.
Michels, D. 1986. Personal Communication. Don Michels
Associates, Los Angeles, California.
National Academy of Sciences, National Academy of
Engineering. 1974. Water quality criteria, 1972.
U.S. Government Printing Office, Washington, D.C.
Republic Geothermal Inc. 1985. Unalaska Geothermal Project
Phase III Final Report. Prepared for Alaska Power
Authority, Anchorage, Alaska. 107 pages.
Robison, D. 1986. Personal Communication. EPA, Anchorage,
Alaska.
Shaul, A. 1986. Personal Communication. ADF&G, Commercial
Fisheries Division, Kodiak, Alaska.
SIGMA Environmental Consultants LTD. 1983. Summary of
water quality criteria for salmonid hatcheries.
Prepared for the Department of Fisheries and Ocean,
Canada.
Weitkamp, D.E., and M. Katz. 1980. A review of dissolved
gas supersaturation literature. Trans. Am. Fish. Soc.,
109:659-707.
Woodward Clyde Consultants. 1978. Impact Prediction Manual
for Geothermal Development. Prepared for U.S. Dept. of
“Interior, Fish and Wildlife Service, Office of
Biological Services, Western Energy and Land Use Team.
FWS/OBS - 78/77, Lccc #78-600108, EPA-IAG-D6-E685,
118 pages.
-39-
Appendix A. Scale Analysis of Coho Salmon Collected from
Makushin and Driftwood Streams.
Fish Location Length (mm ) Circuli Checks
1 M3 46 1 0
2 M3 47 1 0
3 M3 40 nsi/
4 M3 60 4 0
5 M3 45 0 0
6 M3 50 2 0
7 M3 55 4 0)
8 M3 84 12 0
9 M3 58 4 0
10 M3 85 su2/
11 M3 92 10 0
12 M4 50 4 0
13 M4 45 1 0
14 M4 36 NS
15 M4 42 NS
16 -. M4 42 4 0
17 M4 45 NS
18 M4 44 4 0
19 M4 42 3 0
20 M4 39 0 0
5 NS = No Scale.
oa SU = Scale Unreadable.
Appendix A continued.
Fish Location Length (mm) Circuli Checks
21 M4 35 0 0
22 M4 120 14. 0
23 M4 98 12 0
24 M4 104 12 a/
25 M4 70 su
26 M4 75 9 0
27: M4 70 7 0
28 M4 55 6 0
29 M4 51 3 0
30 M4 55 6 0
31 M4 60 6 0
32 M4 45 1 0
33 D1 38 Ns
34 D1 36 NS
35 D1 36 Ns
3/ = A check was found on one scale but other scales from
this fish did not show a check.
aie
Appendix B. Fish Collected by Electrofishing and Minnow
Trapping in Makushin Valley (September 2-3, 1986).
Species and Fork Length (in mm)
Dolly Dolly
Location Varden (E) Varden (T) Coho (E) Coho (T)
M1 254 140
125 120
94 120
53 115
52 110
42 110
105 110
100 90
95 115
123 90
119 110
99 95
110 115
135 110
135 110
115 110
140 110
140 115
134 115
100 140
122 i415
110 135
110
85
85
M2 240 110
135 115
120 120
125 90
230
115
130
102
115
125
115
90
105
115
50
120
95
95
Appendix B continued.
Dolly Dolly
Location Varden (E) Varden (T) Coho (E) Coho (T)
M2 cont. 85
85
80
90
75
95
90
80
80
75
85
80
85
60
55
40
45
50
40 -
50
+ approx. 50 more
+ 2 @ 350 mm in
spawning colors
M3 100 120 47 50
90 115 46 84
85 60 40 2
110 120 60 45
60 70 45 92
70 70 85
60 115 58
100 110
45 115
60 115
80 120
45 135
50 115
65 115
40 110
60 125
50 120
40 95
45 90
40 115
45 85
70 80
60 110
40 120
40 105
40 110
45 110
-B2-
Appendix B continued.
Dolly Dolly
Location Varden (E) Varden (T) Coho (E) Coho (T)
40 85
M3 cont. 35 103
+ approx. 50 more 85
104
65
113
75
76
70
70
65
75
70
62
M4 110 85 42 120 85 100 50 98 85 95 60 104 80 90 42 70 76 7 45 15 77 80 39 60
84 . 95 44 70 79 90 40 50 68 70 49 55
65 110 45 oe
80 75 42 45
50 50 35
45 60 36
85
110
75
80
140
80
85
110
60
(E) (T)
Captured by electrofishing.
Captured by minnow trapping.
-B3-
Appendix C. Fish Collected by Electrofishing in Driftwood
Valley (September 2-3, 1986)
Species and Fork Length (in mm)
Dolly
Location Varden Coho
D1 107 36
52 36
46 38
40
45
48
52
D2 No Fish Found
Appendix D. Fish Collected by Electrofishing and Minnow Trapping in Glacier Valley (September 2-4, 1986).
Species and Fork Length (in mm)
Dolly 1/ Dolly 2/ Location Varden (E)= Varden (T)=
Gl 128 120
135 145
190 100
177 135
135 120
130 135
112 155
100 115 + 2 @ 150 mm 125
in spawning 140
colors 135
115
145
130
135
130
135
95
105
80
115
95
G2 160
110
80
95
115
80
88
58
80
80
75
85
78
80
65
85
67
75
67
65
70
55
65
63
57
55 1/ 88 z/ Captured by electrofishing.
= Captured by minnow trapping.
APPENDIX E
ADF&G CULVERT INSTALLATION GUIDELINES
Culverts should be installed so that at least one-fifth
of the diameter or 18 inches of the diameter, whichever
is less, of each round culvert or at least 12 inches of
the height of each elliptical or arch type culvert, is
set below the streambed at both the inlet and outlet of
the culvert. This guideline does not apply to
bottomless culverts.
Culverts should be installed so that water velocities
do not impede fish passage. Table E-1 represents water
velocities through different culvert lengths which can
be successfully negotiated by several Alaska fish
species. Factors to be considered in the application
of this table include:
ie average cross sectional velocities at the outlet
of the culvert should not exceed the velocities in
the table except for a period not exceeding
48 hours during the mean annual flood;
2. the culvert should be designed to accommodate
upstream movement of the fish group in Table E-1
that includes the slowest swimming fish species
present.
Each culvert should be placed in and aligned with the
hydraulic gradient of the natural stream. The
effective slope of the culvert at any point along its
length should not exceed 1.0 percent for culverts less
than or equal to 80 feet long nor exceed 0.5 percent
for culverts greater than 80 feet long.
Each bank cut, slope, fill, and exposed earth work
attributable to culvert installation in streams, rivers
or lakes, should be stabilized with approved materials
properly installed to prevent erosion during and after
the project.
An alternative drainage structure should be installed
if the requirements of these guidelines cannot be met.
An alternative drainage structure may include a bridge
or a modified culvert.
Culverts should not be installed in fish spawning areas
or significant rearing habitats.
TABLE E-1: MAXIMUM ALLOWABLE
AVERAGE CROSS SECTIONAL VELOCITIES
IN FEET/SECOND MEASURED 1/
AT THE OUTLET OF THE CULVERT —
Length of
culvert in
feet Velocities in feet/second
Group 12/ Group 113/ Group r1r4/
30 4.6 6.8 9.9
40 4.5 5.8 8.5
50 4.0 5.0 7.5
60 3.6 4.6 6.6
70 3.3 4.2 6.0
80 3.0 3.9 5.5
90 2.8 3.7 5.1
100 2.5 3.4 4.8
150 1.8 2.8 3.7
200 1.8 2.4 3.1
200+ 1.8 2.4 3.0
1/ Velocities may not be exceeded for more than 48 consecutive hours during the mean
annual flood.
Group I--Adult and juvenile low performance swimmers: including such species as
grayling, longnose sucker, whitefish, burbot, sheefish, Northern pike, Dolly
Varden/Arctic Char, nine-spine stickleback, slimy sculpin, and upstream migrant salmon
fry.
Group II--Adult moderate performance swimmers: including such species as pink salmon,
chum salmon, rainbow trout, and cutthroat trout.
Group III--Adult high performance swimmers: including such species as chinook salmon,
coho salmon, sockeye salmon, and steelhead.
~E2-
166°50'
Cp"
_PLATE-2-
Topographic Map of
A Portion of
THE NT. MAKUSHIN AREA
UNALASKA, ALASKA
Produced for
THE ALASKA POWER AUTHORITY
REPUBLIC GEOTHERMAL INC.
Map Completion Date: October [982
Contour Interval: 40'
Date of Photography: 8-1- 82
4000.
Magnetic Declination: |5° East S bd 1 / Woy, WE )) ) (US : PE STNG a = = Gy , 7 | Sas 4 " SS yy) a TS J CF S iP 9 n \ hi ENS ot Wai yf & & ‘ Z EN § i iy} Le : KUW 5 f ! Yi 2 t PRINS YB SW (C : 2 \ JI ° ¢ ~ ‘ $ Sy SEL 1 53° 50°
__53°50!
— LAC SRE aN (3
MHZ \\ son9 |
oY iahe.s
53° 55°
A SHH) V\\\)
oo CIO G23: ——————— 20, SN 7a
= —/800 eS oo
=
SS
= SS
WM
FEES
167°
186955"
+166°5¢'
SIT) oT
+ —— aS 8 SIZt O}.00 ; =|/= leo SE (a UNALASKA BAY Sed i S¢2 1 a¢Ee2 Wage eo MAKUSHIN VALLEY & VICINITY
UNALASKA, ALASKA RIIQW
RI8W “ON SAJAYNS TVINaV OslOVd HLYON Aq pasodaig