EPA/600/3-85/005
January 1985
Site-Specific Water Quality Studies of the Straight River, Minnesota:
Complex Effluent Toxicity, Zinc. Tpxicity, and Biological Survey Relationships
by
Anthony R. Carlson and Thomas-H. Roush.
U-S. Environmental Protection Agency
Environmental Research Laborator.y-Duluth
6201 Congdon Boulevard
Duluth, Minnesota 55804
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO
EPA/600/3-85/005
3 RECIPIENT'S ACCESSION NO.
5 U0703
4 TITLE AND SUBTITLE
Site-Specific Water Quality Studies of the Straight
River, Minnesota: Complex Effluent Toxicity, Zinc
Toxicity, and Biological Survey Relationships
5 REPORT DATE
January 1985
6 PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
A.R. Carlson and T.H. Roush
8 PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency
Environmental Research Laboratory-Duluth
6201 Congdon Boulevard
Duluth, Minnesota 55804
10 PROGRAM ELEMENT NO.
11 CONTRACT/GRANT NO
12..SPONSORING AGENCY NAME AND ADDRESS
Office of Research and Development
Environmental Research Laboratory
U.S. Environmental Protection Agency
Duluth, Minnesota 55804
13 TYPE OF REPORT AND PERIOD COVERED
14 SPONSORING AGENCY CODE
EPA-600/03
15 SUPPLEMENTARY NOTES
16 ABSTRACT
comparative laboratory toxicity tests using Ceriodaphnia reticulata and the fathead
minnow Pimephales promelas were conducted to establish relationships between the
toxicity of a sewage treatment plant effluent containing high concentrations of zinc,
toxicity of the effluent in the receiving water, toxicity of zinc added to the
receiving water and a reference water, and receiving water biota survey data. Water
and biota were sampled under summer (3 times), fall (once) and winter (once)
conditions over a one year period. The relationships were used in evaluating the
protectiveness of a site-specific water quality criterion derived for zinc. A
strong correlation between the effluents toxicity to daphnids was established,
however, toxicity correlation with adverse impact on river biota could not be
established r
It was concluded that the effluent did not adversely affect taxa composition and
abundance at 2 miles (3.2 km) below the discharge to the river. At 2 miles the
zinc concentrations ranged from 100 to 154 g/1 and averaged 144 g/1 on 3 of 4
sampling dates indicating that a site-specific criterion average concentration of
145 g/1, approximately 3 times greater than the national average concentration,
would be protective of river biota.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b IDENTIFIERS/OPEN ENDED TERMS
c COS AT I Field/Croup
8 DISTRIBUTION STATEMENT
19 SECURITY CLASS (ThaReport)
Unclassified
21 NO OF.P.AGES
[59~ ^
2O SECURITY CLASS (Tha page/
Unclassified
22 PRICE
EPA Fotm 2220-1 (R«». 4-77) PREVIOUS EDITION is OBSOLETE
1
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NOTICE
This document has been reviewed ir. accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
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INTRODUCTION
The physical and/or chemical characteristics of water in'a natural
/ t 7 '
system may alter the biological availability and/or toxicity of a material
such as zinc. Guidelines for deriving site-specific water quality criteria
which take these factors into account have been published by the U.S.
Environmental Protection Agency (hereafter referred to as the site-specific
guidelines) (U.S. EPA, 1983A). One guideline approach is to simply test a.,.
' ' " c
prescribed number of resident species in site water to meet minimum data
requirements from which a site criterion is calculated. Another approach is
to test sensitive" "indicator or surrogate species" from the same population
in both clean reference water, hereafter referred to as laboratory water, "and
i *
site water at the same time (except for water characteristics) under similar
. conditions. The ratio of site water toxicity value/lab water toxicity value
is used to modify the national criteria value to a site-specific value.v Both
of these criteria derivation approaches are based on the assumptions: (1)
that differences in the toxicity values of a specific material determined in
laboratory water and site water may be attributed to chemical (e.g.,
complexing ligands) and/or physical '(e.g., adsorption) factors that alter the
biological availability and/or toxicity of a material and (2) that selected
i
test species directly integrate differences in the biological availability
and/or toxicity of the material and provide a direct measure of the capacity
of a site water to increase or decrease toxicity values relative to values
t
obtained in laboratory water. Such single chemical criteria address effects
r,
of pollutants on aquatic life in the absence,of other pollutants in the water
column, a condition which seldom occurs. A chemical of interest is usually
one component of many components in an effluent which may affect the
f
chemicals biological availability and/or toxicity.
1
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The objectives of this research project were (l)"to evaluate the use of
- . i- > *
sublethal toxicity test endpoints (effects on survival, growth, and' ,
1 <
reproduction of selected species) obtained in effluent dilution and- receiving
I * -k rt »
water tests for predicting impacts on resident biota; and (2) to determine if
« . ' A
site-specific water quality criteria are protective under complexed ambient
conditions caused by a point source effluent.- vx _, ,'
l % - ' * i _ ,
The objectives were,approached by. conducting aquatic toxicity tests to
establish relationships between the toxicity of a sewage plant'effluent (STP)
N 1
' ; *"
containing high concentrations of zinc, toxicity of the effluent in the ,
receiving water, toxicity of zinc added to receiving water and a -laboratory
water, and biological survey data.
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MATERIALS AND METHODS
'Site Selection
'The Straight River near Owatonna, Minnesota, was selected for study
because site monitoring data (Minnesota Pollution Control Agency, 1979)
indicated that zinc concentrations below the Owatonna STP discharge were in
excess of the national water quality criteria average concentration of 47
lig/1 (U.S. EPA, 1980). The Owatonna STP receives both municipal and
industrial wastes. The industrial wastes include effluents from several
metal plating operations.
\ ' *' «
The Straight River is a part of the Cannon River watershed.' Approxi1-
- ' i
oately 465 square miles (1,200 knr) of south central Minnesota are' drained .,
by this river and its tributaries.- The specific river reach .studied was from^
1 ' f' *--.'
just upstream of the city of Owatonna STP outfall at river mile 24/8 '(43.1 ' *
km) downstream to river mile 20.1 (32.3 km). Water and b£ota sampling
" , ^ * * r '
stations were established within this reach of the river: station*! f
* '
(reference station) was located 100 yds (91.4 m) upstream from the STP
.*' - . '"
outfall (bridge on North Street), station 2 at river"mile-23.6/(38.0 Ion)
(bridge on Steele County Highway 34), station 3 at river'mile 22'.1 (35.6 km)
(bridge on Clinton Falls Township'road in sections 28 and 23, T108N R20W),
and station 4 at river mile 20.1 (bridge on Steele County Highway 9). These
stations correspond to those used by the State in a previous "Load Allocation
Study" of the river (Minnesota Pollution Control Agency, 1979). Not all of
the stations were sampled on each date, also, several stations in addition to
station 1 through 4 were sampled. Station 1A, located approximately 5 miles
(8.0 km) upstream from.station 1 off county highway 18, was sampled on
\ '
7-27-83. "Station IB, located approximately 1 mile (1.6. km) upstream from
station 1, was sampled on 2-15-83. This station,was located several hundred
3
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yards downstream from a small reservoir. Station 1C was located about 20
feet (6.1 m) upstream from the STP effluent discharge to the river and
station 2A was downstream about 20 ft in the discharge plume. Both 1C and 2A
were sampled on September 10, 1982. Station 2B was located approximately 3/4
mile (1.2 km) downstream from the discharge and was sampled only for fish on
7-28-83. Station 5 was approximately 5 miles downstream from station 1 and
was sampled only for plankton on 7-27-83.
Effluent and Stream Water Sampling
Grab samples of the effluent and receiving water were collected in 19
liter polyethylene jugs and transported within 5 hr to the Environmental
Research Laboratory-Duluth (ERL-D) where they were used immediately in
toxicity tests or stored at ~10 C prior to use in toxicity tests. Samples
for testing were collected on 8-17-82, 9-10-82, 2-16-83, 6-27-83 and 7-28-83.
An exception was that a 7 hr composite sample of the effluent was collected
between 9:00 a.m. and 4:00 p.m. on 7-28-83.
Toxicity Testing
Several toxicity tests were conducted for criteria development and
comparative purposes. Daphnids Ceriodaphnia reticulata and larval fathead
minnows Pimephales promelas were exposed to zinc added to clean laboratory
water (Lake Superior), upstream water (station 1), and downstream "no effect"
water (station 3). Effluent dilution and receiving stream water toxicity
tests were also conducted to acertain whether or not the effluent was toxic
and if it had a measurable impact on biota in the stream after mixing.
Toxicity endpoints measured were effects on survival and growth of fathead
minnow larvae and survival and reproductive effects on the daphnids.
Test waters were usually warmed on a hot plate or in a water bath to
room temperature and then aerated to bring dissolved oxygen concentration to
4
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or near air saturation. The effluent dilution concentrations were made by '
measuring effluent and stream water (from station 1) using graduated
cylinders of various sizes and mixing each concentration in.one-gallon (3.'8
liters) polyethylene or glass .beakers. Enough was mixed for both the fathea'd
minnow and daphnid test at one time. All samples were at or near dissolved
oxygen saturation when solutions were made up.
The daphnids, from the ERL-D culture unit maintained in Lake Superior
water, were usually placed one animal to each of ten 30-ral glass beakers for
each effluent concentration, receiving water sample, or zinc addition sample
tested. Test duration was usually 7 days. Fifteen ml of test water were
placed in each beaker and a daphnid, less than 6 hr old, was added. One drop
of water containing 250 ug of yeast was added to each beaker daily. When
young were present, they were counted and discarded. Temperatures were
maintained at 23-25 C. In tests using water collected on 9-10-82 and 2-16-82
the animal was moved on day 2 and 4 of the test to a new 15 ml volume with an
eye dropper and yeast again added* In tests using water, samples collected on
9-10-83, only 5 daphnids were used per treatment and the tests were ended
after four days of exposure. - In tests using water~collected on 6-27-83 and
i ,
7-28-83 the animals were moved daily. For details of the procedures used see
Mount and Norberg (1984). .
The 7 day fathead survival and growth tests were started by placing 40
larvae (>24-hr-old), from the ERL-D culture unit maintained in Lake Superior
water, to glass tanks containing, 2.5 liters of water attach treatment.
The larvae were equally divided among 4 compartments of the tanks. Each
i i i
compartment was separated by a screen on one side which allowed the draining
and renewal of test solution. Approximately 2 liters of the solutions was
changed daily. Larvae were offered food 3 times a day and tanks
5 -
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were cleaned after the last feeding. Temperatures -were maintained at 23-25
^ *** ' f
C. For details of the procedure used see Norberg and Mount (in press).
Acute toxicity tests were conducted using daphnids (<6-hr-old) and
fathead minnows (<24-hr-old) at 23-25 C. Ten animals were tested at each
concentration. t Five animals were placed into duplicate,test containers/at
: ' '
each treatment. Daphnids were tested in 30 ml glass beake'rs containing 15 ml
of water and exposed for 48 hr under static water conditions. Fa'thead ""
minnows were tested in 500 ml glass beakers containing 200- m-1 of water and
exposed for 96 hr under static or daily renewal water conditions.
Chemical-Physical Conditions
Selected physical and chemical characteristics of the test water samples
are presented in Tables 1 and 2.
Methods of analysis used for total hardness, total alkalinity, conduc-
tivity, pH, dissolved oxygen, chlorine, ammonia, nitrate, nitrite, total
solids and suspended solids are described by the American Public Health
Association et al. (1980). Dissolved oxygen concentrations of the water in
selected treatments of all tests were measured at the end of a test or Just
t
before a water change 'in order to estimate minimum occurring values. Minimum
dissolved oxygen concentrations in the daphnid and fathead minnow tests were
'greater than 6 or 5 mg/1, respectively. An exception was in fathead minnow
test tanks containing 100 and 30% effluent collected on 6-27-83. ' Dissolved
oxygen concentrations of 4.8 mg/1 in 100% effluent and 4.5 mg/1 in 30% were
t
measured oh the fourth day of the test and lower concentrations of 2.9 in
100% effluent and 4.0 in 30% effluent were measured the fifth day.
Procedures for sampling and flame and flameless atomic absorption
spectrophotometry analysis of zinc, chromium, copper, lead and cadmium were
6
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taken from "Methods for Chemical Analyses of Water and Wastes (U.S. EPA,
1979).
The zinc exposure stock solutions were prepared using Fisher reagent
grade zinc-chloride dissolved in deionized water.
The trimmed Spearman-Karber Method (Hamilton et al., 1-977) was used for
estimating median lethal concentration (LCSOs). One way analysis of variance
and Dunnett's procedure (Steel and Torrie, 1960) for comparing all treatments
with a'control (P=0.95) was used to identify significant differences in
endpoints measured in the 7 day daphnid and fathead minnow tests.
Biological Survey Methods
Surveys of the Straight River biota were conducted in the immediate
* '
vicinity of the water sampling stations. They were completed within 24 hrs
of the time water samples were withdrawn for toxicity testing. These surveys
were designed to determine the distribution of aquatic organisms in
relationship' to the Owatonna STP effluent for correlation with effluent
dilution and receiving- stream water toxicity test results. Only macroinver-
tebrate populations were sampled on 8-17-82 and 9-10-82. On 2-15-83 plankton
sampling was added and on 6-27-83 and 7-28-83 fish sampling was added.
Plankton were sampled by holding a Wisconsin type sampler (80 \i mesh) in
the stream for 2 minutes. Two samples were taken at each location. The rate
of stream flow was estimated by timing the passage of a floating object over
a distance of 10 feet (3.05 m) during the 7-27-83 sampling. Plankton were
T
identified to the lowest convenient taxon using a Sedgewick-Rafter counting
cell and a compound microscope at lOOx. The 2-15-83 and 6-27-83 sample
results are reported as total numbers collected per sample and the 7-27-83
results are reported as density (mean number/liter).
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Benthie macroinvertebrates were sampled (one sample at stations 1 and 2)
with a Surber sampler (1024 \i mesh) on 8-17-82. Sampling, on 9-10-82 was
qualitative and was done with-a hand held dip net (508 u mesh). On 6-27-83
(3 replicates at each station) and 7-27-83 (5 replicates at each.station)
quantitative sampling was done with a standard Hess sampler (800 x 900 y.
mesh) and qualitative sampling was done with dip nets. The dip nets were
used in an attempt to sample as many habitats as possible at each station.
All samples were preserved in 10% formalin and later sorted- using sugar
flotation and magnification. Identification was generally made to genus.
The quantitative Hess samples are reported as the mean number per square ,
meter. The qualitative dip net samples and Surber samples are reported as
total number collected at each station.
On 6-27-83 and 7-28-83, shoreline seining using a 15' (4.6 m) x 4' (1.2
m) seine with 3/16"' (0.88 cm) mesh and a backpack electrofishing unit were
used to collect fish. The fish were either identified on site and released
or preserved in 10% formalin for later identification. On 7-28-83 an
intensive fish seining effort was, undertaken between the effluent discharge
and station 2. Periodic seine hauls were made as the collectors moved down
,i i
the river from station 2B which was established-approximately 1/4 mile (0.4
km) upstream from station 2.
Quality Assurance ' ,
*.~ * "
Coordination of the various studies was completed by the authors.
Details of sampling, transfer of samples, storage of samples, specific
i
sampling sites, dates of collections and measurements, to be'^made on each
sample was delineated. We were responsible for all quality assurance related
decisions onsite or in the laboratory.
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All instruments were calibrated by methods provided by the
manufacturers- Methods in the referenced published reports were followed.
For quality control data see Appendix 1.
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RESULTS AND DISCUSSION
E ffluent _Toxicl_ty
Daphnid All STP effluent samples were toxic to the daphnids. On
8-17-82, all of the daphnids died within 24 hr of exposure to 100% .effluent
collected before and after chlorination. The chlorinated and non-chlorinated
samples contained 4,565 and 4,765 ug/1 zinc, respectively. At the 25%
effluent concentrations, with nominal zinc concentration of 1,141 in
chlorinated samples'and 1,191 ug/1 in the non-chlorinated samples, all
daphnids were dead within the 48 hr test period., At 1% effluent concentra-
tions, the chlorinated sampl'e, (nominal 46 ug/1 zinc) killed all of the
daphnids while 90% survived in the non-chlorinated sample (.nominal 48 ug/1
zinc). Also, 90% survived in a 1% effluent^concentration of.^aerated
.',' \ ' » '
subsample of the chlorinated effluent.' Apparently,'chlorination contributed
, V -. "
to the effluents toxicity. Survival of daphnids1 for 48 hr was not affected
* t f *' * (
in upstream control water'(<44 ug/1 zinc) (station 1), however, no daphnids
1
survived in downstream water containing effluent. (300- ug/1 zinc) and
collected from station 2. Daphnids responded similarly when exposed in water
samples collected on 9-10-82. No daphnids survived in 100% effluent (2,850
ug/1 zinc). Survival was not affected in' station 1 water (<10 ug/1 zinc) and
each test animal produced young (1 brood). Survival and young production was
affected in water collected downstream from the effluent discharge. No
daphnids survived to produce young in water (100 ug/1 zinc) from station 2,
and 60% survived but did not reproduce in water (<100 ug/1 zinc) collected
from station 3. Exposure to a 3% effluent concentration of the STP sample
(192 ug/1 zinc) collected on 2-16-83 killed 100% of the daphnids (Table 3).
Survival for 7 days and young production were not affected at a 1% effluent
concentration when compared to the control (12 ug/1 zinc) (station 1 water).
10
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All daphnids survived in the control, water from station 1 (Table' 4);, fy>,
" s > '".,'' r 1 '
daphnids survived in the water from station 2 (211 jig/1 zinc) and .only {20% ,
'
survived in the water from station 3 ,(136 iig/1 zinc) resulting an a* 'large' >
' «. I" x i L *
, '*,,.. v. - ». , ' ir a ' ' »
reduction in1 the young produced per original, female when compared "to.1 thej _
*r "
* *
control (Table 4).' Exposure to 10% effluent concentrations *bf the STP \ *.
" - ./,' * - » » ')
\ - ' - .»{*'. -*.",'
samples collected on 6-27-83 (nominal' 282 ug/1 zinc) and 7-28-83 (223 tyg/T
' jf , l'- ' " ' « ? '
v . ' , i .,, K. '
zinc) killed 100% of the daph'nids (Table 3). Survival and young .production
^ .",..*'
were not affected at 3 and 1%' effluent concentrations (< nominal, 85 ug/1 "- -
~ ~* ' l . /'
zinc) when compared to the control. 'No differences in daptinid- survival* and .
3V - ' _ , '- .^ _'.',,-'''
young production were evident between upstream (4-6 mg/1 zinc)- and 'downstream
,f" * ' *
(107-200 ug/1 zinc) water exposures (Table 4).
r
Based on percentage effluent, the 2-16-83 effluent , sample, was the most-
t r i
toxic to the daphnids when compared 'to the 6-27-83 and 7-28-83 samples- This''.
' > ' '
difference in toxicityappears to be related to the zinc component of the
. ' <
effluent (Table 3'). The range between tlie highest non-eff,ect and lowest
effect effluent dilutions in the 7 day tests on 2-16-83, 6-27-83; and 7-28-83-
were 1T3Z (43-192 yg/1 zinc), 3-10% (nominal 85-282 vig/1 zinc), and 3-10%
(68-225 ug/1 zinc), respectively. .Although less of the effluent collected on
* > k " .
2-15-83 was needed to cause a toxic response, noneffect and effect zinc , >
concentration determined for the effluent overlapped those" determined >for
samples collected on the other date's. This difference in effluent tbxicity
and similarity , in effect zinc concentrations are also reflected in the acute
toxicity values calculated from the data obtained in the first 48 hr of the 7
day tests (Table 5) .
- Fathead Minnow ; Survival and growth data (Table 6) for the fathead
f *
minnows exposed for 7 days to the STP effluent samples collected on 6-27-83
and 7-28-83 demonstrated that the fathead minnows were not ''as sensitive as
J . v
11
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the daphnids to the STP effluent. The range betwen the highest non-effect
and lowest effect effluent dilution was 30-100% in each test for the fatheads
compared to 3-10% for the daphnids. Specifically, no fish~survived in the
6-27-83 100% effluent sample (2,825 ug/1 zinc). Survival at this
concentration may have been affected by the effluents biological oxygen
' demand which resulted in low dissolved oxygen concentrations in the test
chamber during the last 3 days of testing. Survival was not affected but
mean weight was reduced by 30% in the 7-28-83 100% effluent,'sample (2,395
yg/1 zinc) when compared to the control (6 ug/1 zinc) (station 1 water). For
both dates at 30%- (nominal 847 ug/1 zinc) or less effluent dilutions, mean
survival and weight values were similar to that obtained in the controls.* No
differences in 7 day survival or growth were evident between upstream (4-6
' ' ' * l ',
ug/1 zinc) and downstream (107-200 ug/1 zinc) water exposures (Table 7);. -
- ' ' *
The.STP effluent sample collected on 8-27-82 was toxic to fathead
* ' +"
minnows at the 100% effluent concentration. .In the chlorinated sample, fish
i.
died within the first 2 hr of exposure. 'In the non-chlorinated sample all '
I ' r * > ' '
were alive within this time frame but were dead when checked 12 hr later.
t
This difference in time to death indicates that the chlorine was contributing
to toxicLty. No effluent dilution of this effluent sample were tes'ted,
\
, B \
however, in tests conducted using upstream' control water (station 1) and
downstream-(station 2) water containing the effluent, all'fish'.survived.
Zinc Addition, ', * '' ' > ''",' ' '
Daphnid -In 'zinc addition tests using dilution wa'ter -collected from
, . " ' . ..-; - - -', i, " , . ." , ,
J , " ', , ' ' ' .- -n
not affected at zinc concentrations ranging from 24 to 58 ug/-l (Table"'8,V. 'At '
' III s ' * 1
,; the 101- ng/1 zinc concentration, .a 45%. reduction in the mean'-number of'young
per original femalelvwhen compared to the control was observed.-'," No.ne survived
' ' 12
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-,to produce young' at the,198 ug/1 zinc exposure. In a similar test with water
collected oh 7-28-83 (Table 8) survival and growth were not demonstrably *
affected at zinc concentrations ranging from 18 to 140 ug/1., At 618 iig/1
none survived to produce young. Unexplained control mortality was observed
near the end of the test resulting in reduced-young production. Such
mortality was not observed in the 18 to 140 ug/1 treatments and in a
replicate control set-up at approximately the same time for the STP effluent
and receiving water tests. The ranges between the highest non-effect and
lowest effect zinc concentrations of 58-101 yg/1 and 140-618 ug/1 for water
collected on,2-16-83 and 7-28-83, respectively, indicate that zinc was less
biologically available and/or toxic in water collected on 7-28-83 than in
water collected on 2-16-83. Acute toxicity values obtained for daphnids
during the first 48 hr of these tests differed by two-fold and support this
trend (Table 9). '
The toxicity of receiving water collected at station 3 on 2-16-83 was
directly attributed to the zinc component of the effluent. The range of
58-101 ug/1 zinc between the highest non-effect and lowest effect zinc
concentrations using water collected from station 1 (.Table 8) was within the
43-192 yg/1 range determined for zinc in the effluent dilution test (Table
3). Similar acute toxicity values (48 hr LC50) of 114 and 91 ng/1 were
calculated from the zinc addition and effluent tests, respectively (Tables 9
and 5). In both of these treatments -water collected from station 1 served as
dilution water and the control. This control water contained 12 pg/1 zinc
* i
and was not, toxic to the daphnids. Station 2 water, which contained 211 ug/1
directly attributable to the effluetnt, killed all of the exposed daphnids "
(Table 4) within the first 48 hr of the 7 day test period. Station 3 water.
i "i '
i ' *
which contained 136 yg/1 zinc killed only 60% of the daphnids within the
,13
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first 48 hrs (Table 4).' This mortality in station 3 water is essentially
k
equivalent to the 50% mortality predicted based on the zinc addition and
effluent dilution LC50 values (Tables 9 and 5).
The zinc component of the effluent sample collected on ,6-27-83
apparently was not as biologically available and/or toxic to daphnids as was
* « * ' *
the zinc added to station 1 water.( A nominal 48 hr LC50 of 134 ug/1 .zinc
(Table 5) was calculated 'from the effluent test results. Station 2, 3, and
water which contained 107, 150, andsl49 ug/1 were not toxic. All of these
, % i.
zinc concentrations are higher than the 48,hr LC50 of 96 U8/1 (Table 9)
resulting from zinc addition to station 1 water. In station 3 water, to
which zinc was added, a 48 hr LC50 of 195 ug/1 was obtained and indicates a
two-fold reduction in zinc biological availability and/or toxicity when
compared to the station 1 LC50 value (Table 9). This value is directly
comparable -to the station 1 LC50 value because it was obtained from a test
conducted at the same time under similar conditions.
The zinc component of the effluent collected on 7-28-83 appeared to be
more biologically available and/or toxic when diluted with station 1 water
than zinc added to station 1 water. Although the ranges-"of zinc concentra-
tions between the highest non-effect ,and lowest effect concentration in the 7,
day daphnid tests overlapped, the 48 hr LC50 of 134 calculated from the
effluent dilution data was about two-fold less than the zinc addition 48 hr
i «
LC50 of 264 us/1 (Tables 5 and 9). The station 2 and 3 samples were not'
toxic but contained 200 and 150 mg/1 zinc, respectively...(Table 3). Both of
/ t
'» -
these zinc concentrations were in excess of the effluent dilution LC50 value
but less than the zinc addition LC50 value. These data indicate that another
component(s) of the effluent may have been contributing'to the toxicity of
14
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the effluent, and that toxicity of the componentCs) did not persist but was
ameliorated by river conditions by the time the effluent reached station 2.
. Site Water vs. Lab Water
Acute toxicity data obtained in concurrent zinc addition tests in Lake
Superior (lab water) and Straight River water (site water) indicate that zinc
was less biologically available and/or toxic'in site-water (Table 9).
Daphnid water effect ratios (site water LC50/lab water LC50) of 5.5 and 3.0
were calculated from tests on site water collected from station 1 on 8-17-82
and 6-27-83. A daphnid water effect ratio of 6 was calculated for station 3
water collected on 6-27-83. For site waters collected on 6-27-83 the data
indicates that the fathead minnow water-effect ratio was greater than 6.7.
Tests of each species at the same time in lab and site water collected on
7-28-83 were unsuccessful because of procedural problems in the lab water
tests, however, site water tests were completed. These tests differed from
. the previous tests in that the daphnids were fed and the fathead minno.w test
solutions were renewed daily. If the previously measured lab LC50 values for
s»
these species determined for water collected on 6-27-83 are used in
:
calculating zinc water effect ratios, ratios of 8.2 for daphnids and 5.5 for
\
fathead minnows result.
Biological Survey
Macroinvertebrate A 50% reduction in benthic macroinvertebrate taxa
composition was evident between stations 1 (reference station) and 2 on
8-17-82 (Table 10). No marked difference in taxa composition was evident in
samples collected from stations 1, 2, and 3 on 9-10-82. The greatest
difference in composition was between station IB and station 1. Taxa
compositions of samples collected on 2-15-83 were more diverse (Table 11) .
Total taxa in each sample ranged from 17 to 19. Station IB and 3 samples
15
-------
(station 2 was ice covered) contained only 11 taxa each in common with the
station 1 sample. Taxa composition of station 1 and 2 samples collected on
6-27-83 differed markedly (Table 11). Station 1 -samples contained 27 taxa
while station 2 samples contained only 15 with 8 of them in common with
station 1. Six taxa (Satis, Ephron, Hydropsyche, Stenelnus, and Chironomid
pupae) with densities greater than 10 per square meter at station 1 were not
found at station 2. At station 3 a more diverse taxa was evident; 39 taxa
were identified in the samples, of which 18 were in common with those found
at station 1. Five of the six taxa not found in station 2 samples were
present in station 3 samples at approximately the same or greater density
than at station 1. The mayfly taxon Ephron was absent. Total organism
density was 11.6 times less at station 2 and 3.1 times greater at station 3
when compared to station 1. On 7-27-83 the differences in macroinvertebrate
taxa composition between stations 1, 2 and 3 were not as evident as in June,
however, a similar'trend in organism density was evident- When compared to
station 1, total organism density was 2.3 times greater at station 1A, 3.4
i' - ' ."
times less at station 2, 7.2 times,greater at station 3 and 2.4 times greater
at station 4. - .
i * t * * *
Plankton Zoo plankton', taxa were, found-in" low Cumbers at each station
'*',''<
(Tables 12 and 13). Phytoplankton were more numerous but present mostly as
diatoms which were not identified to lower taxa. Stations IB and 3 samples
collected on 2-15-83 each contained 7 taxa with 5 and 4 respectively in
common with the station 1 sample. On 6-27-83 station 1 samples contained 12
taxa all of which were found in station 2 samples which contained 14 taxa.
On'this date markedly less taxa were found'in'station 3 samples which
contained only 3 taxa in common with station 1 samples. This trend in taxa
composition at stations 1, 2 and 3 was not evident on 7-27-83. Stations 1, 2
16
-------
and 3 samples contained 13, 14 and 12 taxa, respectively, with station 2 and
v ; ,
3 samples containing 12 and 10 taxa, respectively,' in common with station 1
) j
samples. Station 1A samples (5 miles upstream) contained 7,taxa all' found at
station 1. The difference in station 1A taxa>when compared to station 1 is
thought to be reflective of the reservoirs influence on taxa composition.
For example, daphnids were not found above the reservoir but were present
below the reservoir. Station 4 samples contained 11 taxa of which 10 were in
common with station 1. Station 5 (5 miles downstream) contained 8 taxa with
only 4 in common with station 1.
Fish Fish species composition differences at stations 1,2 and 3 are
apparent in the data obtained from collections made on 6-27-83 (Table 14).
Thirteen species were collected at station 1 while 7 and 11 were collected at
station 2 and 3, respectively. The station^ and 3 samples contained 5 and 8
species, respectively, in common with the station 1 sample. Species
t
composition differences between samples collected at stations 1, 2 and 3 on
7-28-83 were evident but less diverse when compared to samples collected at
these stations on 6-27-83. Station 1^samples contained 12 species while
station 2 samples contained '-only 8 species, 7 of which were in common with
^ "' , ' " , . t
the station 1 sample, however,''the station 2B sample contained 11 species, 10
in common with the statio'n' 1 sample. On'this date periodic seine hauls, made
.-,- - , <
as the collectors moved down' the river from station 1 to a point
' >l "
approximately 1/4 mile above station 2,'produced only^a few fish (sand
shiners). Most hauls were empty.' 'Sampling station'2^8 was established at
j ft.
this point and approximately- the same seining effort was expended as at a
A " "" **
regular station. The station 3 samples contained 12 species with 8 in common
with the station 1 sample. Station 4 samples contained 14 species with 10 in
17
-------
common with the station 1 sample. The station 1A (located 5 miles upstream)
sample diverged the most from station 1 composition, it contained 9 species ,
-^
with only 4 in common with the station 1 sample. This sample also contained
larval catostomids which were not found at any other station.
j\
Toxicity and Effluent Impact
Under the conditions of this study strong correlations between the
Owatonna SIP effluent toxlcity to daphnids and adverse impacts on the
Straight River biota could not be made, however, the biological survey data
indicates that the effluent at times may affect taxa distribution and'
abundance. The daphnid tests indicated that water at station 2 was toxic on
8-17-82. Based on zinc concentration the station 2 water sampled was
approximately 5% effluent by volume. Concurrent benthic macroinvertebrate
sampling indicated a marked reduction in taxa composition at this station
when compared to reference station-1. This data is of limited use in making
toxicity vs impact correlations because only a small area of the stream was
sampled. However, the mean water discharge of the river was 49 cf-s on this
date and had been declining from 451 cfs on 7-17-83 (Appendix 2) indicating
that prior exposure of resident biota to effluent concentrations toxic to the
daphnids was possible. River discharge increased from 42 cfs on 8-21-82 to
553 cfs on 9-2-82 from which it declined to 152 cfs on 9-10-82. On 9-10-82,'
water sampled at station 2 was estimated to be 3% effluent by volume based on
zinc concentration. Intensive qualitative sampling with di'p nets on this
date indicated that there was very little difference between taxa composition
at stations 1, 2 and 3 even though the daphnid tests indicated that the water
was toxic at stations 2 and 3: Also at'this time very little difference in
taxa composition was evident between 3 upstream stations and a station
f "*
located within the effluent plume. On 2-15-83 station 3 water,, estimated to
18
-------
be 4% effluent by volume based on zinc concentration, was also toxic to
daphnids. Toxicity to daphnids would have been expected at 3% effluent based
on the effluent dilution toxiclty tests. The mean water discharge of the
river for this date was 138 cfs and had decreased from 205 to 133 cfs over
the previous 40 days indicating long-term exposure at concentrations which
were toxic to daphnids was possible, however, during this period the river
was under winter conditions of low water temperature (1 C on 2-15-83) which
is known to markedly reduce the toxicity of many substances including zinc
(U.S. EPA, 1980) to aquatic life.' At this time station 3 benthic macro-
invertebrate and plankton taxa composition differed markedly from station 1,
however, taxa composition at station IB, located approximately 1 mile
upstream also differed markedly from station 1. This upstream-downstream
variation in taxa composition relative to the reference station indicates
that effluent caused impacts cannot be inferred from this data. Water
collected from station 1, 2, 3 and 4 on 6-27-83 was not toxic to daphnids,
however, macrobenthic invertebrate, zooplankton, and fish populations
appeared to be adversely affected by the effluent. At this time six of- the
most numerous macro-benthic taxa at station 1 were not found at station 2 and
organism density at station 2 was 65 fold less than at station 1. Five of
the six taxa missing at station 2 were found at station 3 where organism
density was 3.1 fold greater than at station 1. The plankton taxa
composition at stations 1 and 2 was similar but markedly different at station
3 where only 3 of 12 taxa common to station 1 were found. Fish species
composition also differed markedly between station 1 and station 2. The zinc
1 ' * i
concentrations at station 2 indicated that the effluent concentration was'
i
about 3.4% of the water volume. This effluent concentration would not be
expected to be toxic to daphnids based on the effluent dilution test results.
19
-------
The mean river discharge on this date was 159 cfs and -had declined from
!
spring'and early summer high flow conditions indicating'that'.exposure to »
' ' i
resident biota to effluent concentrations toxic to the daphnids was even less
probable, however, the occurrence and effects of slug doses 'or zinc cannot be
ruled out and will be discussed in the following zinc site' specific criteria
. *'
section. Stream flow remained relatively stable until 7-1-83. On this day
mean river discharge increased to 4,420 cfs from which it declined to 121 cfs
on 7-28-83. Water collected from the, downstream stations on 7-28-83 again
was not toxic to daphnids. 'The station 2 water sample was approximately 10%
effluent by volume based on zinc concentration and would have been predicted
to be toxic based on the effluent dilution £est results. -Apparently the
effluents toxicity was ameliorated by the river. At this time the
^
composition of the benthic macroinvertebrate taxa, plankton taxa, and fish
species at stations'1, 2, 3 and 4 were not markedly different. Five out of
the six benthic macroinvertebrate taxa not found at station 2 on 6-27-83 were
present at ,this time. The benthic macroinvertebrate densities were 3.3-fold
r
less and 7.2-fold greater at stations 2 and 3, respectively, when compared to
station 1. Comparison of these data to those obtained on'6-27-83 indicated
that the stream was.recovering from an adverse Impact below the STP effluent
i ,
, T.
discharge. The absence of fish encountered in the intensive seining effort
\ T j I
made on 7-28-83 between the STP effluent discharge to the river and station
2A approximately 3/4 mile downstream was also indicative of the STP effluent
' ~ ' , i
"affecting fish distribution.
1 * , . f
The lack of strong correlations between effluent toxicity to, daphnids
J 4 J r
and biological impact in the stream may have teen due ^to not Sampling 'and
i * ' ' ' ', ',"''
testing the effluent and receiving-wa'ter over a sufficientr'number of'days to
.' « ' - * ' , ',>* ""..'"," '* '" ' "
get a measure of the duration of exposure of the resident -biota to" conditions, j
20
-------
toxic to the test animals. Often river flow had been higher prior to
sampling indicating that susceptible biota may not have time to react to
adverse conditions. The higher flow may also have contributed to biota
recolonization which may have masked effluent impact.
Site-Specific Zinc Criteria
To use the indicator species procedure of the site-specific guidelines
to derive a site criterion for zinc, the resident species range of
sensitivity for the chemical of interest should be similar to that for
species in the national criteria document (U.S. EPA, 1980). Daphnia magna
was identified in this document as the most sensitive species tested based on
acute toxicity and among the two most sensitive' species tested based on
chronic toxicity. Because Daphnidae were also found at the study site it was
assumed that the range of resident species sensitivity to zinc was similar to
that for species used to establish national criteria. The indicator species
Ceriodaphnia reticulata used in this study and Daphnia magna have also been
shown to be equally sensitive to zinc in 48 hr toxicity tests (Mount and
<
Norberg, 1984).
A water quality criterion consists of two concentrations: the criterion
maximum concentration and the criterion average concentration. To protect
aquatic life and its uses in the Straight River, in each 30 consecutive days
the site-specific average and maximum concentrations for zinc should not be
exceeded; and the concentration may be between the average concentration and
the maximum concentration for up to 96 hr.
Since daphnids were markedly more sensitive to zinc than the fathead
minnows, the daphnid data was used to calculate a site-specific water quality
criterion. Data for water collected on 6-27-83 was the only set that met all
but one of the requirements of the indicator species procedure of the
21
-------
site-specific guidelines (U.S. EPA, 1983). The exception was that LC50
values used in calculating the daphnid water effect ratio for zinc could' not
be shown to be statistically different using recommended procedures.^ For the.
site water, 96 pg/1 zinc LC50, a 95% confidence ititerval could not be
calculated using the Trimmed Spearman-Karber method because of the nature of
the mortality data; 100% died at" 140 ug/1 zinc, the highest concentration
tested, and none died at 60 ug/1 zinc. However,- for the lab water LC50 of 32
fc * ' " i »
' ' , 4 , I
Ug/1, the 95% confidence interval of 26-40 ug/1 does not overlap the above 60
ug/1 site water no-effect concentration indicating that the>water effect
ratio of 3 calculated from this data is a valid estimate of the difference
"* *
between waters in the biological,,availability and/or toxicity of zinc to the
V f " ,
daphnids. This water effect ratio; was used to calculate a site-specific
!>' s '
maximum concentration for zinc in the^following-equation:
s-
Site-Specific Maximum Concentration = Water Effect Ratio x National Maximum
Concentration (at lab water hardness)
Site-Specific Maximum Concentration = 3 x 145 ug/1 zinc = 435 ug/1 zinc ..
The national maximum concentration used in the calculation and those here-
after discussed were derived according to the revised national guidelines
(U.S. EPA, 1983) using the data presented in the national criteria document
(U.S. EPA, 1980). This site-specific maximum concentration is more restric-
tive than a national maximum concentration of 801 ug/1 zinc derived for the
Straight River at a water hardness of 353 mg/1. The site-specific average
concentration of 145 mg/1 was obtained by dividing the site-specific maximum
concentration by the national acute-chronic ratio of 3. The site-specific
average concentration is less restrictive than the national average
concentration of 47 ug/1 for all waters.
22
-------
Analysis of STP monitoring data for metals as reported to the Minnesota
Pollution Control Agency by the City of Owatonna, U.S. Geological Survey flow
data (Appendix 2), and data obtained in this study demonstrate that zinc
concentrations at and below station 2 exceeded the site-specific average (145
Hg/1) and maximum (435 ug/1) concentration under low flow conditions in the
Straight River during the one year period of this study. For the five water
samples collected at station 2, zinc concentrations averaged 236 ug/1- and
ranged from 100 to 380 ug/1 (Table 1). For station 3, zinc concentrations
ranged from <100 to 154 yg/1 and averaged 14A ug/1 on 3 of 4'sampling d-ates.
On these dates the effluent samples averaged 2.6 mg/1'zinc and'the average^
t '
discharge of the Straight River system was 140 cfs and ranged from 49 cfs o'n-
8-17-82 to 159- cfs on 6-27-83. The average discharges for the months of
August and January were below 140 cfs indicating that even higher'30 day
average zinc concentrations were possible. Relatively high e'ffluent zinc
concentrations of 17.0 and 20.5 mg/1 for samples analyzed on 9-16-82 and
9-30-82, respectively, were reported by the city. The other 21 effluent zinc
concentrations reported within the one year time frame of this^ study ranged
from 0.04 to 5.32 mg/1 and averaged 2.32 mg/1 with a standard deviation of
1.28 mg/1. From 9-26-82 to 9-30-82 the daily average river discharge ranged
from 126 to 158 cfs. High concentration of zinc in the effluent during this
'period of time would undoubtably have resulted in a zinc concentration higher
than the site-specific maximum concentration at and below station 2. This
conclusion is supported by reported measured concentration of 830 ug/1'zinc
in water collected from station 2 on 2-2-78 (Minnesota Pollution Control
<
Agency, 1979).
The apparent adverse effluent impact on biota at station 2 could not be
attributed to the zinc component of the STP effluent. The effluent contained,
23
-------
many other potential toxic components besides zinc, several of which were'
measured (Tabies 1 and 2). Because it contained domestic wastes, it also
contained dissolved and solid forms,of nutrients that contribute to increased
biological activity in the receiving stream. For example, increased
' ^
bacterial nitrification is evident when ammonia, nitrite,_and nitrate
i "
concentrations from station 2 are compared to station 1 (Table 2),. Increased
biological activity at station 2 coupled with seasonal variability -in the
t
flow and other physical, chemical and biological conditions all affect the >
- <
distribution and abundance of the species inhabiting this station.^ Because ,
of this inherent variability it was not possible to sort out.possible
l
intermittant zinc toxicity effects on biota using information obtained from
this study.
Under the conditions of this study the distribution of benthic-
macroinvertebrates and fish did not appear to be adversely impacted by the
STP effluent or its zinc component at station 3. At this station, zinc
concentrations ranged from <100 to 154 ng/1 on the 4 sampling dates and
averaged 144 ug/1 on 3 of 4 sampling dates. The total number of
/
benthic-macroinvertebrate taxa (Figure 1) found at this station were similar
or greater than found at station 1 on the four sampling dates. The total
number of fish species were similar (Figure 2) between station 1 and 3 on the
two dates they were sampled. The total number of plankton'taxa were markedly
less, when compared to station 1, on 1 of the 3 dates they were sampled
(Figure 3). This difference could have been due to upstream effluent impacts
causing plankton death and sedimentation and/or predation. Nevertheless, if
the assumption of the national (U.S. EPA, 1983B) and site-specific guidelines
that the protection of site-species all of the time is not necessary because
aquatic life can tolerate some stress and occasional adverse effects
24
-------
Is taken into consideration, these data indicate that the site-specific-
criterion average concentration of 145 pg/1 would be protective of Straight
River biota.
25
-------
ACKNOWLEDGMENTS
We thank Donald Mount, Nelson Thomas, Scott Heinritz, Dean Hammer-
meister, and Carol Church for their contributions to this study. -
26
-------
LITERATURE CITED
American Public Health Association, American Water Works Association, and
Water Pollution Control Federation. 1980. Standard methods for the
examination of water and waste water. 15th ed. Washington, B.C. 1134
pp.
Hamilton, M. A., R. C. Russo, and R. V. Thurston. 1977. Trimmed Spearman-
Karber method for estimated median lethal concentrations in toxicity
bioassays. Environ. Sci. Technol. 7: 714-719. Correction 12: 417
T. *
(1978).
Minnesota Pollution Control Agency. 1979. Load allocation study for the
Straight River below Owatonna, Minnesota. Division of Water Quality,
Surface and Groundwater Section,'1935 West County Road B2, Roseville,
Minnesota 55113.
Mount, D. I., and T. J. Norberg. (1984). A seven-day life-cycle cladoceran
" toxicitytest. Environ. Toxicol. Chem. 3: 425-434.
Norberg, T. J., and D. I. Mount. (In Press). A new subchronic fathead
minnow toxicity test. U.S. EPA, Environmental Research
Laboratory-Duluth, Duluth, Minnesota 55804.
Steel, R. G. D., and J. H. Torrie. 1960. Principles and procedures of
statistics with special reference to the biological sciences.
McGraw-Hill, New York. 481 pp.
U.S. Environmental Protection Agency. 1983a. Water Quality Standards
Handbook. Guidelines for deriving site-specific water quality criteria.
Office of Water Regulations and Standards, Washington, D.C. 20460.
27
-------
U.S. Environmental Protection Agency.. 1983b. Guidelines for deriving'
numerical national water quality criteria fqr^the protection of aquatic'
-"''' ., \ (
life arid its uses. Draft July 5, 1983. U.S*. EPA, Environmental '
- ' .*, ' , , ; :
. Research Laboratories'at Duluth, 'Minnesota; Gulf-Breeze,'. Florida;
' ' * v
Narragansett, Rhode Island; and Corvallis, Oregon.
i ' . ^ '
U.S. Environmental Protection Agency? L980. Ambient water quality criteria
for zinc. EPA-440/5-80-079. Office of Water Regulations and Standards
Division. Washington, D.C. ,20460. '
U.S. Environmental Protection Agency. 1979. Methods for chemical analysis
of water and wastes. EPA-600/4-79-020. U.S. 'EPA1, Environmental
Monitoring1 and Support Laboratory. Cincinnati, 'Ohio 45268. "*
28
-------
Table 1. Total hardness, total alkalinity, conductivity, and selected metal concentrations ot the Ovatonna STP and receiving water samples used In toxic I ry testing.
Date Total Hardness
Test Water Source Sampled (mg/l as CaCOj)
Station 1 8-17-82
("100 yds above STP) 9-10-82
2-16-83
6-27-83
7-28-83
Station 2 8-17-82
(-1.2 tulles baton STP) 9-1O-82
2-16-83
6-27-83
7-28-83
Station 3 9-10-82
(-2.7 miles balov STP) 2-16-83
6-27-83
t>0 7-28-83
VO
Station 4 6-27-83
(-5 miles balowSTP) 7-28-83
STP Effluent 8-17-82
9-10-82
2-16-83
6-27-83
7-28-83
353
376
394
362
376
-
378
392
376
_
380
380
374
-
374
339
-
359
284
274
Total Alkalinity Conductivity
(mg/l as CaCO-j) (umho)
268
388
320
276 720
_ _
-
428
350
278 825
_
425
350
277 825
340
275 740
_
-
1,400
750
219 1,910
pH
7.9
7.9
7.9
7.7
7.3
-
7.9
7.8
7.6
_
e.o
7.9
7.6
7.9
7.6
7.2
-
-
7.6
7.5
7.2
Total Zn
(ug/l)
<44
-------
Table 2. Turbidity, total solids, total suspended solids, ammonia, 'nitrate, nitrite and .total chlorine
concentrations of .the Owatfdnna STP and receiving water samples' collected on 7-28-83.
Turbidity Total Solids
Test Water Source . (NTU) (mg/1)
Station 1 30 866 -
>' (-100 yds above STP)
Station 2 31 ' 606
(~1.2 miles below STP).
Station 3 31 877
(-2.7 miles below STP)'
Station 4 * 29 554
(~5 miles below STP)
STP effluent 38 902
Total Suspended NH3N N03N ' N02N C12«
Solids (mg/1) (mg/1) ' (mg/1) (mg/1) (mg/1)
51 , 0.10 3.18 <0.025 '<0.020
v * -
46 - 0'.32 t 3.71' 0.025 <0.020
*
47 0.19 3.60 <0.025
.
43 ' 0.04 - 3.64 <0:025
"i *
32 ' 2.5 9.50 <0.025 <0.020a
, , ^ <- , ' 0.190b
a Composite sample.
b Sample collected at the end,of the-discharge pipe..
-------
Table 3. Young production and percentage survival of
daphnidsi Ceriodaphnia reticulata (N=10) in Owatonna STP
effluent and
several dilutions made with receiving
corresponding zinc concentrations.
water, and
STP Effluent
Percentage
Effluent
(v/v)
, 100
30
10
3
1
Control
100
30
10
3
1
Control
Total Zinc
Concentration
Ug/1
Grab Sample
'2,967 '
' ' l;440
267
192
. 43
12 .
Crab Sample
2,825
84 7C
282C
85 c
28C
4
Young/ Female
* r
(2-16-83)
0.0a
X).0a
0.0a
0.0a
9.9 (3.6)b
9.7 (2.3)b
(6-27-83)
I
0.0a
o.oa
o.oa
16.9 (11.4)b
18.2 (12.7)b
20.0 (11.0)b
Composite Sample (7-28-83)
' 100
30
10
,3
1
Control
2,395
665
225
68
-
6
0.0a
0.0a
o.oa
13.6 (5.0)b
19.4 (4.3)b
14.3 (6.2)b
Percentage
Survival
Oa
Oa
Oa
Oa
100
100
Oa
Oa
' Oa
80
80
80
i
<, oa
oa'
oa.
80
100
90
a Significantly different than the control (P-0.95)
b One standard deviation in parenthesis.
c Nominal values.
31
-------
Table 4. Young production and percentage survival of daphnids Ceriodaphnia reticulata (N=10) in
OJ
N>
1
2
3
4
receiving water collected from
Date of
River Water
Station Mile Collection
i
(Above STP) 24.8 J- -2-16-83
.'% ' 6-27-83
7-28-83
(Below STP) 23.6 2-16-83
6-27-83
- ,. " 7-28-83
(Below STP) 22,1 >, 2-16-83
6-27-83
7-28-83
(Below STP) 19.8 6-27-83 .
7-28-83
above and below
Total Zinc
Concentration
(|ig/D
' 12
4
6 "
211
107 ,
200 (90)b'
128
154
150 (95)b
149
86 (29)b
the Owatonna
Young/
Female
9.7
20.0
14.3
Oa
22.7
10.0
1.6a
19.6
12.7
26.1
16.3
STP discharge.
Standard
Deviation
2.2 *
11.0
6.2
5.7
' 2.6
3.4
10.0
5.2
2.5
7.0
Percentage
Survival
100
80
90
Oa
100
70
20a
80
90
100
100
a Significantly different than station 1 (P=0.95).
" Dissolved"zinc concentration (yg/1).
-------
CO
CO
Table 5. Acute toxicity.values (LCSOs) obtained during the first 48 hr ,of the 7 day exposures of daphnid
Ceriodaphnia reticulata and fathead minnow Pimeph'ales promelas in Owatonna STP effluent dilutions.
1 - t
X
.
,
Total
Test Water Date Hardness
Source . Sampled (pg/1)
STP effluent 2-16-83 359
* 6-27-83 .' 380 -"
'
7-28-83 274
. ( * **
Daphnid 4(3 hr'
LC50
-Tbtgl-' Dissolved
% . Zinc ' Zinc
Effluent" J'Xug/1) (ug/1) '
1.7 ' , 91
-
4.7 134a - -
i "
5. '5 124 , 79
Fathead Minnow
96 hr, LC50
Total Dissolved
% Zinc Zinc
Effluent (Ug/1) ' (ug/1)
* *
f
76 <2,148a ' '-
(58-99) (1,653-2,793)
>2,395 >998
a Nominal value based on measured zinc concentrations-in 100% effluent.
-------
Table 6. Survival and growth data for larval fathead minnows
Pimephales promelas exposed to Owatonna SIP effluent and
several
Percentage
Effluent
(v/v) -
100
30
'10
3
1
Control
dilutions made with receiving water, and
corresponding zinc concentrations.
Total Zinc
'" Concentration
(U8/D
Grab Sample
2,825
847b
282b
85b
28b
4
Mean
Percentage'
Survival
(6-27-83)
oa
92
90
97
95
97
Mean Dry
Weight- (mg)
.34 (.06)
.36 (.09)
.36 (.06)
.39 (.05)
.36 (.05)
Composite Sample (7-28-83)
100
30
10
3
1
Control
2,395
665
225
68
-
6
75
75
85
95
92
82
.28 (.03)a
.49 (.14)
.46 (.07)
.44 (.05)
.39 (0.9)
.41 (.10)
a Significantly different than the control (PM).95).
b Estimated zinc concentration based on the measured
concentration in 100% effluent.
34
-------
Table 7~ Survival and growth data for larval fathead minnows Pimephales promelas exposed
in receiving waters collected from above and below the Owatonna
and corresponding zinc concentrations.
River
Station Mile
1 (Above STP) 24.8
2 (Below STP) 23.6
3- (Below STP) .22.1
4 (Below STP) 19.8
Date of Water
Collection
6-27-83
7-28-83
6-27-83
7-28-83 .
6-27-83
7-28-83
6-27-83
7-28-83
^ Total Zinc
Concentration
(ug/D
4
6
107
200 (90)a
, 151
150 (95)a
_
86 (29)a
STP effluent discharge
Mean
Percentage
Survival1
97"
82 ..
92
87
90
87
97
90
Mean Dry
Weight
(«
.36
.41
.40
.50
.37
.54
.40
.43
>g)
(.06)b
(.10)°
(.04)b
(.09)b
(:05)b
(.08)b
(.06)b
(.09)b
a Dissolved zinc concentration.
b~ One standard deviation.
-------
Table 8. Young production and percent survival of daphnids
Ceriodaphnia reticulata (N=10) obtained from 7 day zinc addition
toxicity tests in upstream water (Station 1). Grab samples-of
dilution water were obtained on 2-16-83 and 7-28-83.
Zinc Concentration
(wg/l)
Total Dissolved,
198
101
58
41
24 - , -\
11 -' ;
(Control)
618 , 460 ( r
140 90
59 ' 31
37 9
18 .5
6 8
(Control)
Young/ Female
2-16-83 Dilution Water
* j
8.8a
12.3 - ,
'20.4
^ 45.5, "'
fl
15.8
f '
7-28-83 Dilution Water
' Oa
5.7
11.4
10.7
13.3
9.3 (14.3)b'
i
Standard
Deviation
-
7.7
4.6
6.2
6.8 *
4.9 '
,'
-
5.9
4.0'
3.5 .
5.8 \ '.
8.7 (6.2)b
Percentage
Survival
'
Oa
80 -
90
100
100
100
' -' oa '.
100
- 90
90
100'
j-
50 (90)b>
a Signficantly different than the control (P = 0.95). . .
b Values for daphnids reared under similar conditions as controls in
the effluent dilution tests.
36
-------
Table 9. Acute toxicity values (LC50s) obtained from static tests in which zinc was added to receiving
water (collected from above and below the STP outfall) and Lake Superior water.
Test Water Date
Source Sampled
Station 1 8-17-82
(Above STP)
2-16-83
6-27-83
7-28-83
Station 3 6-27-83
(Below STP)
7-28-83
Lake Superior
Total Hardness
(Ug/1 as CaC03)
353
376
392
362
392
374
45
Daphnid 48 hr LC50
(ug/1 zinc)
Total Dissolved
224a
(146-343)
114b
96C
264b 180
(206-367) (136-238)
195°
(176-216)
41a
(32-52)
32C
(26-40)
Fathead Minnow 96 hr
LC50 (ug/1 zinc)
Total
-
-
<2,660C
2,159d»e
(1,277-3,649) (1
<2,930C
2,000d«e
(1,542-2,592) (1
396
(315-497)
Dissolved
-
-
<1,960
1,857
,091-3,158)
<2,360
1,545
,205-1,983)
a Nominal values obtained in tests conducted at the same time under similar conditions.
b Test organisms were fed. Data obtained during the first 48 hr of the 7 day daphnid tests.
c»d Values for each species obtained in tests conducted at the same time under similar conditions.
e Test water was renewed every 24 hr. In these tests 20% mortality occurred in the controls.
-------
Table 10. Total number of benthic macroinvertebrates sampled. A
Surber sampler was used on August 17, 1982 and a dip net "kick method"
was used on September 10, 1982 to make the collections. , --
Diptera
Rhagionidae - Atherix
Siraulidae
Chironomidae
Tabanidae
Trichoptera
Hydropsychidae
Hyjd_rop_8_y_ch_g_
Cheumatopayche
Ephemeroptera
Heptageniidae
Stenonema
Hep tag en ia
unidentifiable
Baetidae
Isonichia
Baetis
Caenidae
Tricorythodes
Ephemeridae
Ephoron
Po toman thus
Coleoptera
Elmidae (adults)
(larvae)
Megaloptera
Sialidae - Sialis
Other
Clam
Limpet
Snail
Planaria
Oligochaetes
Leech
August
1 2
1
3 1
4 8
4
3
17 3
3
7
3
3
4 1
1 3
8 3
Station
September
IB 1 1C 2A
123
2866
14 5 1
2 1
53 12 "4 3
16
1
10 1 1
57 4 10 10
8 8 3 10
1 1
2
5222
6 17 6 6
1
1
1
1
" 10 1 3
1
"
2 3
3
4 '13
' ' v 2
1
I
19 22
1
2 3
1
2 2
4 3
1
1
3 1
Number of taxa 12 6 14 11 11 11 10
Taxa in common with
Station 1 -69-879
38
-------
Table 11. Results of quantitative (D) and qualitative (Q) benthlc aquatic macro!nvertebrate sampling of the Straight River near Owatonna, Minnesota
on February 15, 1983, June 27, 1983 and July 27, 1983. Quantitative results are expressed as the mean number per m2. Qualitative results are
expressed as total number collected.
Ephemaroptera
Baetls
Ephoron
Stenonema
Heptagon la
1 sonych I a
Tr 1 cory thodes
Caen 1 s
Paraleptophlebla
Plecoptera
Perlesta
Pteronarcys
Acroneur 1 a
Taen lopteryx
Tr 1 choptera
Hydropsyche
Cheuma tops y che
Hydropsyche Pupae
Pycnopsyche
Hydroptllldae
Leptocerldae
Coleoptera
Stenelmls
Optloservus
Dublraphla
Elmldae
LaccophI I us
Hydroporus
DIptera
Probezzla
Atherlx
TIpula
Simul tdae
Hemerodromta
Ch I ronom 1 dae Pupae
Ab 1 abesmy I a
Stations (February) Stations (June)
IB 1 3 123
0 Q D Q D Q D QDO D Q
2 43 49 43 12
65 17
1 15 2 77 7 1 75
118 94 41 22 10
11 20 29
4
2 73
1
2 4
6 7
25 61 21
2 4 6 1 15 2 36 8 47
28 62 39 2 2 1 4 39 1
2 1
11
29 3 57
18
4 29
39 6 34 16 24 1
1
2 2 18
9492 11
11 2
27 71 97
14
4 5 14 5 147 1
41 714 588 1
D
14
79
18
4
7
4
373
18
22
68
43
1A
Q
39
10
19
3
6
10
1
2
4
5
19
1
1
2
1
7
3
Stations
1 2
D Q D
7 39
90 17 50
39 32
4 9
(July)
Q
2
4
17
1
2
7 16 14
1
4 2
90 13 11
4 12 4
1
11
32 611
4
1
4 2
1
6
1
2
2
1
2
1
3
2
2
3
D Q
29 16
7
47 40
4 3
25 3
165 16
11
4 1
215 16
11
39
79 1
36 1
18
1
47 5
4
7
7 1
118 2
D
11
68
11
47
230
25
4
47
36
29
50
4
11
25
4
Q
9
14
6
8
14
1
43
4
6
3
19
4
7
8
-------
Table 11 (continued)
Dlptera (continued)
Pentaneuna
C. (Dlcrotendlpes)
C. (Cryptochlronomus)
C. (Trlbelos)
Polypedi lum
Stenoch 1 ronomus
Tanytarsus
Rheotanytarsus
Mlcropsectra
Cr 1 cotopus
Nanocladlus
Br 1 1 1 1 a
Psectroc 1 ad 1 us
Trlchocladlus
Metrlocnemus
Odonata
Ischnura
Argla
An ax
Other
Corlxldae
Plea
Slalls
1 sopoda
Hyalella
Hlrudlnae
Planerla
Ferrlsslma
Physa
Plecepoda
Nematoda
01 Igochaete
Decapoda
Total
Number of taxa
Stations (February) Stations (June)
IB 1 3 123
D QDQDO D Q D Q D Q
24 7
11
1 18
2 75
11 24 4 25 1
4 36 4 18 75 2
73 50
2 1
86 17 6 12 155 9 373 20 7 1,130
108
1 4 1 28 2 4 1 54 3
4 4 50
25 1
22 4
6 4
2
2
4 4
2 7
61 1
424 4
11 4
' 2 1 4 1 1 41
241 4
11
2 2 4 183 25 22 129
7 1 18 4 22 6
193 145 348 978 85 3,061
17 . 18 19 27 15 39
Stations (July)
1A 1 2 3 4
DQDQDQD QDQ
41 97 1
2 1
29 152
6 31 4 38 72 14 14 37
4
18 2714
4 1
212 3 47 19
497 2 36 20
1 2 2
377 14 18
4
1 1 1
130 2 1
1 1
2 4 1
4 1
4 4
7
4
4 11 71
2
434
11 4141 43 1 1
5 12 13 4 3 3
724 308 92 2,207 727
30 27 25 36 27
Taxa In common with
Station 1 11 - 11 - 8 18 20 - 17 22 20
-------
Table 12. Number of plankton par sample collected from the Straight River, Owatonna, Minnesota, on February
15, 1983 and June 27, 1983.
Station (February)
IB 1 3
C 1 adocera
Bosmlna 1
Copepods 1
Nauplll 12 9 11
Chlronomldae 1
Nematoda 41
Tardigrade
Branchlonus 1 1
Large Branch Ion Idae 2
Small Branch I on Idae 6 2 1
Bdelloldea 1 8
Polyarthra 4 - 1
Keratella 574
Kelllcottla 3
Fed I astrum
Ceratlum
Desmlds
Solitary Diatoms 8,600 14,675 10,375
1
A'
1
1
3
12
1
1
1
1
1
10
5
24,400
Station
B A
2
1
9 2
16 5
2 4
1 32
1 5
6
1 37
6
4 5
23,550 23,350
(June)
2 3
B A ' B
2
2
2
2
1
11
0
2
8
1
1
t
1
5,300 9,350 6,800
Number of taxa 797 12 14
Taxa In common with
Station 1 5 4 12
-------
(able 1.5. Klankton density (mean number/liter) calculated from samples collected from
the Straight River, Owatonna, Minnesota, July 27, 1983.
Station '
L
Cladocera
Bosmlna
Copepods
Nauplll
Chlronomldae
Nematoda
Tardigrada
Branch lonus
Large Branch) on Idae
Small Branchlonldae
Bdel loidea
Polyarthra
Keratel la
Kelllcottla
Pedlastrum
Ceratlum
Desm I ds
So 1 1 tary D I atoms
1A 1
0.15
0.12
0.04 0.54
0.21 0.77
0.05
0.22
0.09
0.09 0.37
0.12
0.30 0.05
0.18 0.12
0.13 0.22
421.3 697.6
2
0.16
0.11
0.16
0.26
0.15
0.18
0.16
0.11
0.22
2.33
' 0.11
0.11
0.17
423.0
3
0.11
0.16
0.60
0.11
0.60
0.11
0.06
0.28
1.46
11
0.22
0.11
282.0
4 5
- ,
0.19
1.34 ' 0.034
0.13 0.06
1.15 0.61
0.13 . 0.17
0.06
0.96 0.56
2.05 0.71
0.06
,
0.13
393.5 390.8
Number of taxa 7 13 14 12 11
Taxa In common with
Station 1 7 12 10 10
-------
Table 14. Fish collected by setne and electro fish Ing from the Straight River, Owatonna,
Minnesota, July 28, 1983. Presence (denoted by x) or absence of specfes was determined In
June and total number of each species In July. Station 26 was sampled only with the seine.
Station (June)
Station (July)
123 1A 1 2B 2 3 4
Northern pike, Esox luclus x x
Brook stickleback, Culaea Inconstans x
Mu dm In new. Umbra 1 Iml x
Black crapple, Pomoxls n I gromacu 1 atus x
Green sunf Ish, Lepotnls cyanellls x
Pumpklnseed, L. glbbosus
Orangespotted sunf Ish, L. huml Us
Rock bass, Amblopl Ites -rupestrls x x x
Iowa darter, Etheostoma exlla
Johnny darter, E, nlgrum x
Blackslde darter, Perclna maculata
Black Bui 1 head, Ictalurus melas x x
Stonecat,'Noturus flavus
3131 2
21 7 6 9 15
2 5 9 11 . 16'
2 '' _
1 , '
1 1
15 \ 19 12 i 1
9 ' 1 ,
It -» 1 ,
\
Tadpol e_ madtom, N. gyrlnus J ,_!
Carp, Cyprlnus earplo x x 1t 4 J ' 1
Creek chub, Semotl lus.atromaculatus x x 10 73 5 " 3 - 3
Bluntnose minnow, Plmephales notatus x x x 4 ' 10 187 10 7 " 15
Fathead minnow, P. promglas x V5 80 3 10
Sand shiner, Notropls stramlneus x x 17 22 23
Emerald shiner, _N. atherlnoldes '6
Redfln shiner, N. umbratl Ms 68 3
Comnon shiner, _N. cornutus x x 7
Spotfln shiner, N. spl lopterus x 2
Blacknose dace, Rhlnlchthys atrat'ulus x x 1
Larval cyprlnlds x 17 42
White sucker, Catostomus commersonl xxx 69682
Hog sucker, Hypentelluin ntgrlcans x 1 . '
Larval catastomlds 8
Number of species 13 7 11 9 12 11 '8 12 14
Taxa In common with Station 1 584 10 7 ' 8 10
4'T >
-------
40r-
30
X
u.
85
m
20
BENTHOS
a
IA IB
j L
STP
STATION
o Aug
Sept
oFeb
June
A July
Figure 1. Number of bentho-macroinvertebrate taxa identified at each sampling station.
-------
15 r
CO
LJ
a
Q.
CO
U.
O
o:
LJ
FISH
(STRAIGHT RIVER)
June
i July
I
1
IA
I \
STP
2B 2
STATION
j
4
Figure 2. Number of fish species identified at each sampling station.
-------
ON
PLANKTON
(STRAIGHT RIVER)
I5r
UJ
U-
O
a:
LU
QD
oFeb
June
A July
IA
IB
* .
\ "«
STP
STATION
Figure 3. Number of plankton taxa identified at each station.
-------
APPENDIX 1
Quality Control Data
47 -?
-------
Quality control values for measurement of selected metals in test
waters- Values are reported as percentage recovery.
Date of Water
Collection Zinc Copper Cadmium Chromium Lead
Recovery of U.S. EPA'Reference Sample'
8-17-82 100 99 105 ' 93 111
9-10-82 94
2-17-82 100, 101 95 98 104
6-27-82 ' 106 94 105 96
Recovery of a Spike
8-17-82 . 97 , 102 101 90 103
-------
Quality control values for measurements of zinc in tests
using water collected on 6-27-83.
Sample
Daphnia //3 (7/1)
Mount #9 - Initial
FHM, LH20 (6/28)
Reference Sample
EPA W476//1 (N=2) .
WP475//3 (N=4)
% Agreement
' of Duplicates
98.0-
i t<
' 100. 0 '
98 .9'
r
Analytlca-1 Mean
' (ug/D '
* '
6.2
200
t'
i '
% Recovery/ Spike
Concentration
, 103.5/200
, 94.1/r,000
100.8/500
«
* f
True Value
*" '
, 6'1
, 200 -
Ug/1
Mg/1
Mg/1
(Ug/1)
-------
Quality control values for selected metals in tests using water collected
on 7-28-83.
Sample
% Agreement
of Duplicates
Fathead minnow, downstream,
control composite
Daphnia effluent dilution, 3%
)
Fathead minnow, effluent dilution,'
30%
none
no,ne
none
CADMIUM - ACID" EXCHANGEABLE
Fathead minnow, downstream control
composite
100
LEAD - ACID EXCHANGEABLE
Fathead minnow, downstr-eam control " 91.4
CHROMIUM - ACID EXCHANGEABLE
Fathead minnow, downstream control
composite
83.3 -
% Recovery/Spike
Concentration
ZINC - ACID
Daphnia metals addition
Daphnia, upstream
Daphnia, upstream
Fathead minnow, upstream
Fathead minnow, upstream
Daphnia, instream, 2A
Daphnia, downstream
Fathead minnow, downstream
Fathead minnow, downstream
Fathead minnow, effluent dilution
Fathead minnow, effluent dilution
Fathead minnow, Lake Superior water
Fathead minnow, Lake Superior water
Fathead minnow, Lake Superior water
EXCHANGEABLE
86.7
91.2
96.7
99.6
84.2
74.0
42.8
87.3
89.8
86.7
88.6,-
94.9
96.4
98.5
88.0/25 ug/1
75.0/124 ug/1
100.8/245 ug/1
87.9/481 ug/1
93.3/481 us/1
84.3/99 ug/1
88.0/50 ug/1
77.0/99 u'g/1
107/99 ug/1
, 103.2/124 ug/1
94.4/124 ug/1
86.1/481 ug/1
84.6/481 ug/1
83.1/1,724 ug/l
COPPER - ACID EXCHANGEABLE
97.9/8.00 ug/1
98.9/8.00 .ug/1
101.2/16.0 ug/1
,119/1.50 ug/1
1 108/18 ug/1
108/7.0 ug/1
-------
Reference
Concentration _(ug/l)
Analytical
x + 1 SD True Values
Zinc /
EPA WP475 #2 (N=4)
WP475 #3 (N=13)
WP475 #6 (N=3)
Cadmium
WP475 #2 (N=l)
Lead
Chromium
11.7 + 1.6
210 + 14.5
414+0.6
Copper
1 '" < >
WP475 #1 (N=3) 40:9+0.7
WP475 #2 (N=2) 8.04 +'o.2
1.49-
WP475 n CN-3) 18.9 +1.2
*^~
WP475 #2 (N=2) 6.64 + o'.3
12.5
200 -,
400
40.0
1.5
18
-------
Quality control values for selected measurements of water samples collected on 7-28-83.
v
EPA Reference
Test x Exp/True Site
Total alkalinity , 1
Effluent
Total hardness , 1
V ' "' ' ", - . *A
Turbidity . ' - 3
Ammonia nitrogen " 2/5 strength , '' 3 -
;,WP 481, ' -'.^ Eff
0.608/6.600 mg/1
Theory/ exp 1^98 .7%
rec
Nitrite nitrogen >
Nitrate-nitrite *WP481 *N=12 1
nitrogen - 0.65/0.64 mg/1
Residue, non-filterable - 4A
Residue, Total 3
% Agreement
of Duplicates
99.6
99.1
100
100
96.9
95
95.1
95.4
97.4
% Recovery/ Spike
Concentration
97/3.00 mg/1
_
90.3(2.00 mg/1
* Samples were analyzed in conjunction with the Connecticut samples. A cumulative value is given
here.
-------
Quality control values for selected metals in tests of water collected
on 7-28-83.
Metal
Zinc
Copper
Cadmium
Lead
Chromium
Deionized Water Blank
Site 4A''
Spike Recovery/Spike % Agreement
Concentration of Duplicates
Total Recoverable
105.2/160 ug/1
102/100 ug/1
96.7/26.0 ug/1
110.8/240 ug/1 st ^
98.1/160 ug/1 ^
Metals
96.5
77.2
97.7'
91.9
96.7 -''
% Recovery/ Spike
Concentration
105.9/160 ug/1
101.4/100 ug/1
115.4/26 ug/1
104.. 9/266 ug/1
96.6/160 ug/1
-------
APPENDIX 2
Provisional Record
U.S. Geological Survey
Cannon River Basin
05353800 Straight River, Near Faribault, MN
LOCATION Lat 44015'29M, long 93°r-3'51", in W'1/2 SE 1/4 sec. 9, T. 109 N.,
R. 20 W.; Rice County, Hydrologic Unit 07040002, on right bank 15
ft (5 m) downstream from highway bridge, 2.8 miX'4.5 km) upstream
from Falls Creek and 3.2 mi (5.1 km) southeast of Faribault.
DRAINAGE AREA 442 rai2 (1,145 km2')'-
PERIOD OF RECORD October 1965 to current year ."
GAGE Water-stage recorder. Datum of gage is 1,034.58 ft (315.340 m)
National Geodetic Vertical Datum of 1929.
REMARKS Records good except those for winter period,' which are fair.
AVERAGE DISCHARGE -- 17 years,~237 ft3/s (6.712 m3/s), 7.28 in/yr.(185
mm/yr).
EXTREMES FOR PERIOD OF RECORD -- Maximum discharge, 5,990 ft3/s (170
m3/s) May 1, 1973, gage height, 11.20 ft
(3.414 m); maximum gage height, 12.74 ft
(3.883 m) Mar. 5, 1974 (backwater from ice);
minimum discharge, 10 ft3/s (0.28 m3/s)
Oct. 27, 1976; minimum gage height, 3.66 ft
(1.116 m) Nov. 27]' 1976.
-------
Discharge, In cubic feet per second, water year October 1981 to September 1962
Mean Values
Day
,
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IB
19
20
21
22
2i
24
25
26
27
28
29
30
31
Total
Mean
Max
Mln
CFSM
In.
Cat Yr
Wtr Yr
Oct
121
109
107
144
155
182
191
191
I7B
173
164
154
152
180
198
210
306
436
456
417
361
319
285
227
258
249
247
247
247
242
223
7129
230
456
107
.52
.60
1981 Total
1982 Total
Nov
205
197
193
190
189
187
183
174
200
203
193
181
175
169
163
158
151
143
155
151
125
127
129
131
133
145
Ul
140
138
136
4905
164
205
125
.37
.41
101622
111369
Dec
134
133
132
130
128
130
130
120
110
109
111
112
113
114
114
113
112
111
108
105
100
97
94
91
88
85
82
79
76
73
70
3304
107
134
70
.24
.28
Mean
Mean
Jan
67
64
62
59
57
55
52
50
48
47 '
45
44
43
42
42
41
41
40
40
40
40
40
40
40
40
40
40
40
40
40
40
1419
45.8
67
40
.10
.12
278 Max
305 Max
Feb
40
40
40
40
40
40
40
40
40
40
40
40
40
40
42
43
45
48
53
56
62
66
69
70
70
70
70
70
1394
49.8
70
40
.11
.12
2900
2600
Mar
69
68
68
67
66
66
66
66
67
70
100
150
300
600
800
900
1200
1400
1640
1580
1440
1220
1 ISO
1430
1320
1210
1010
850
778
826
982
21589
696
1640
66
1.58
1.82
Mln 28
Mln 40
Apr
905
749
709
569
528
456
433
393
388
363
346
406
494
523
554
664
UOQ
1160
988
874
737
621
538
480
428
388
350
325
302
282
17053
568
1160
282
1.29
t.44
CFSM .63
CFSM .69
May
267
249
238
249
466
654
874
862
737
611
499
489
814
1020
1010,
975
975
1260
1100
950
760
714
709
670
595
543
590
616
579
584
2600
23259
750
2600
238
1.70
1.96
In 8.55
In 9.37
Jun
2020
1520
1070
784
632
538
494
442
406
371
338
313
286
264
275
271
215
294
298
275
260
242
228
235
313
271
249
228
207
191
13590
453
2020
191
1.03
1.14
Jul
178
166
166
157
140
143
238
456
325
256
306
282
221
198
201
302
451
380
275
217
194
182
160
140
126
121
115
105
98
93
88
6480
209
456
88
.47
.55
Aug
79
77
75
73
75
73
69
67
63
61
59
55
55
53
51
49
49
48
48
46
42
69
61
103
107
121
95
72
130
171
169
2365
76.3
171
42
.17
.20
Sep
470
553
470
322
227
189
171
154
UO
152
145
202
555
636
652
600
530
438
352
283
235
205
186
169
152
141
134
126
135
158
8882
296
652
126
.67
.75
-------
Discharge, In cubic feet per second. Mater year October 1982 to September 1983
Mean Values
Day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IB
19
20
21
22
23
24
25
26
27
28
29
30
31
Total
Mean
Max
Mln
CFSM
In.
AC-FT
Oct
238
382
492
513
480
457
478
451
418
371
332
304
281
265
252
232
216
209
216
630
962
967
852
720
604
508
442
396
372
340
314
13694
442
967
209
1.00
1.15
27160
Nov
300
282
252
257
244
234
228
219
217
634
1080
1360
1330
1190
999
839
699
590
604
758
772
691
604
529
471
412
389
353
359
346
17242
575
1360
217
1.30
1.45
34200
Dec
310
347
387
398
377
376
386
379
319
310
300
297
280
278
254
250
250
256
204
193
195
199
181
215
761
824
680
415
272
270
262
10425
336
824
181
.76
.88
20680
Jan
238
227
220
215
205
195
190
185
175
172
170
167
163
160
157
152
150
150
150
150
150
150
150
150
147
144
140
135
130
130
130
5147
166
238
130
.38
.43
10210
Feb
130
130
130
130
130
130
130
130
130
130
130
130
130
130
133
138
147
165
180
225
390
650
1000
990
940
920
920
1360
9978
356
1360
130
.81
.84
19790
Mar
1900
2740
2930
2800
2530
2410
2520
2250
1720
1370
1150
954
835
766
739
701
653
646
703
716
629
547
501
477
475
469
454
428
459
484
1100
37056
1195
2930
428
2.70
3.12
73500
Apr
1990
2080
1870
1620
1410
1320
1360
1290
1200
1180
1310
1320
1910
2270
2170
2040
1920
1770
1680
1820
2280
2540
2280
1880
1530
1280
1050
869
766
682
--
48687
1623
2540
682
3.67
4.10
96570
May
622
751
799
745
649
720
1820
1620
1320
1040
837
728
770
731
662
582
526
489
568
691
721
641
553
494
450
414
448
461
475
478
463
22268
718
1820
414
1.62
1.87
44170
Jun
429
396
382
355
333
320
308
298
293
285
273
264
253
265
243
223
204
200
196
198
196
191
179
166
160
158
159
171
198
292
~
7588
253
429
158
.57
.64
15050
Jul
4420
4790
3380
2960
2600
2170
1760
1460
1220
958
731
570
475
405
349
308
280
259
245
243
211
187
170
154
143
132
123
121
117
107
98
31146
1005
4790
98
2.27
2.62
61780
Aug
89
83
81
77
73
69
65
60
59
56
54
51
50
48
47
46
46
45
43
41
46
44
43
42
391
240
323
321
271
415
333
3652
118
415
41
.27
.31
7240
Sep
276
206
160
131
130
126
127
111
108
95
94
88
86
82
110
171
173
159
192
1780
1890
1660
1390
1140
923
755
621
502
408
335
14029
468
1890
82
1.06
1.18
27830
Htr Yr 1983 Total 220912 Mean 605 Max 4790 Mln 41 CFSM 1.37 In 18.59 AC-FT 436200
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