U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
LAKE BEMIDJI
KLTRAMI COUNTY
MINNESOTA
REGION V
WORKING PAPER No,
PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY
An Associate Laboratory of the
NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON
and
NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA
•fcOPO 697.O32
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REPORT
ON
LAKE BEMIDJI
BELTRAMI CQUM1Y
MINNESOTA
EPA REGION V
WORKING PAPER No, 84
WITH THE COOPERATION OF THE
MINNESOTA POLLUTION CONTROL AGENCY
AND THE
MINNESOTA NATIONAL GUARD
NOVEMBER, 1974
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1
CONTENTS
Page
Foreword ii
List of Minnesota Study Lakes iv, v
Lake and Drainage Area Maps vi, vii
Sections
I. Conclusions 1
II. Lake and Drainage Basin Characteristics 3
III. Lake Uater Quality Summary 4
IV. Nutrient Loadings 9
V. Literature Reviewed 13
VI. Appendices 14
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11
FOREWORD
The National Eutrophication Survey was initiated in 1972 In
response to an Administration commitment to investigate the nation-
wide threat of accelerated eutrophication to fresh water lakes and
reservoi rs.
OBJECTIVES
The Survey was designed to develop, in conjunction with state
environmental agencies, information on nutrient sources, concentrations,
and impact on selected freshwater lakes as a basis for formulating
comprehensive and coordinated national, regional, and state management
practices relating to point-source discharge reduction and non-point
source pollution abatement in lake watersheds.
ANALYTIC APPROACH
The mathematical and statistical procedures selected for the
Survey’s eutrophication analysis are based on related concepts that:
a. A generalized representation or model relating
sources, concentrations, and impacts can be constructed.
b. By applying measurements of relevant parameters
associated with lake degradation, the generalized model
can be transformed into an operational representation of
a lake, its drainage basin, and related nutrients.
c. With such a transformation, an assessment of the
potential for eutrophication control can be made.
LAKE ANALYSIS
In this report, the first stage of evaluation of lake and water-
shed data collected from the study lake and its drainage basin is
documented. The report is formatted to provide state environmental
agencies with specific information for basin planning [ 3O3(e)], water
quality criteria/standards review [ 3O3(c)], clean lakes [ 3l4(a,b)],
and water quality monitoring [ 1O6 and §305(b)] activities mandated
by the Federal Water Pollution Control Act Amendments of 1972.
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111
Beyond the single lake analysis, broader based correlations
between nutrient concentrations (and loading) and trophic condi-
tion are being made to advance the rationale and data base for
refinement of nutrient water quality criteria for the Nation’s
fresh water lakes 0 Likewise, multivariate evaluations for the
relationships between land use, nutrient export, and trophic
condition, by lake class or use, are being developed to assist
in the formulation of planning guidelines and policies by EPA
and to augment plans implementation by the states.
ACKNOWLEDGMENT
ThL if of the National Eutrophication Suivey (Office of
Research & Development, U. S. Environmental Protection Agency)
expresses sincere appreciation to the tlinnesota Pollution Control
Agency for professional involvement and to the Minnesota National
Guard for conducting the tributary sampling phase of the Survey.
Grant J. Merritt, Director of the Minnesota Pollution Control
Agency, John F. McGuire, Chief, and Joel G. Schilling, Biologist,
of the Section of Surface and Groundwater, Division of Water Quality,
provided invaluable lake documentation and counsel during the course
of the Survey; and the staff of the Section of Municipal Works, Divi-
sion of Water Quality, were most helpful in identifying point sources
and soliciting municipal participation in the Survey.
Major General Chester J. Moeglein, the Adjutant General of
Minnesota, and Project Officer Major Adrian Beltrand, who directed
the volunteer efforts of the Minnesota National Guardsmen, are also
gratefully acknowledged for their assistance to the Survey.
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iv
NATIONAL EUTROPHICATION SURVEY
STUDY LAKES
STATE OF MINNESOTA
LAKE NAME COUNTY
Albert Lea Freeborn
Andrusia Beltran’ii
Badger Polk
Bartlett Koochiching
Bear Freeborn
Bemidji Beltrami
Big Stearns
Big Stone Big Stone, MN; Roberts,
Grant, SD
Birch Cass
Bi ackduck Bel trami
Blackhoof Crow Wing
Budd Martin
Buffalo Wright
Calhoun Hennepin
Carlos Douglas
Carrigan Wright
Cass Beltrami, Cass
Clearwater Wright, Stearns
Cokato Wright
Cranberry Crow Wing
Darling Douglas
Elbow St. Louis
Embarass St. Louis
Fall Lake
Forest Washington
Green Kandiyohi
Gull Cass
Heron Jackson
Leech Cass
Le Homme Dieu Douglas
Lily Blue Earth
Little Grant
Lost St. Louis
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V
LAKE NAME COUNTY
Madison Blue Earth
Malmedal Pope
Mashkenode St. Louis
McQuade St. Louis
Minnetonka Hennepin
Minnewaska Pope
Mud Itasca
Nest Kandiyohi
Pelican St. Louis
Pepin Goodhue, Wabasha, MN;
Pierce, Pepin, WI
Rabbit Crow Wing
Sakatah Le Sueur
Shagawa St. Louis
Silver McLeod
Six Mile St. Louis
Spring Washington, Dakota
St. Croix Washington, MN; St. Croix,
Pierce, WI
St. Louis Bay St. Louis, MN; Douglas, WI
Superior Bay St. Louis, MN; Douglas, WI
Swan Itasca
Trace Todd
Trout Itasca
Wagonga Kandlyohi
Wallmark Chisago
White Bear Washington
Winona Douglas
Wolf Beltrami, Hubbard
Woodcock Kandiyohi
Zumbro Olmstead, Wabasha
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940 30’
470 30’
Lav nia
27A.
WOL
LAK
a
BEMIDJI, WOLF, ANDRUSIA
& CASS LAKES
Tributary Sampling Site
Lake Sampling Site
Sewage Treatment Facility
Map Location
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940 55
0
94 45’
nap Location
ilavinia
47° 30’
LAKE BEMIDJI
Tributary Sampling Site
Lake Samplinq Site
Sewage Treatment Facility
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LAKE BEMIDJI
STORET NO. 27C1
I. CONCLUSIONS
A. Trophic Condition:
Survey data show that Lake Bemidji is eutrophic. Of the
60 Minnesota lakes sampled in the fall when essentially all
were well-mixed, 28 had less mean total phosphorus, 36 had
less mean dissolved phosphorus, but only 5 had less mean
inorganic nitrogen. Of the 80 lakes studied, 24% had less
mean chlorophyll a, and 19% had greater Secchi disc transparency.
Marked depression of dissolved oxygen with depth was noted at
station 1 in July and September and at station 2 in July, 1972.
Reportedly, a portion of Lake Bemidji was chemically treated
for algae control in 1971 (Bonnema and Johnson, 1972).
B. Rate-Limiting Nutrient:
The results of the algal assay show that the lake was nitro-
gen limited at the time the assay sample was collected. Lake
data indicate nitrogen limitation at the other sampling times
as well.
C. Nutrient Controllability:
There are no known point sources impacting Lake Bemidji
within the limits of the Survey. The N/P ratio of 28/1 in
the mean annual nutrient loads of the inlet (see page 12)
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2
suggests that point sources in the drainage are not large nutrient
contributors (of course, Lake Irving provides some phosphorus
entrappment, but it is unlikely that It is enough to account for
the N/P ratio observed).
During the sampling year, Lake Bemidji received a total
phosphorus load at a rate less than that proposed by Vollenweider
(in press) as “dangerous” (i.e., a eutrophic rate) but more than
a “permissible” or oligotrophic rate (see page 12).
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3
II. LAKE AND DRAINAGE BASIN CHARACTERISTICS
A. Lake Morphometryt:
1. Surface area: 6,420 acres.
2. Mean depth: 32 feet.
3. Maximum depth: 76 feet.
4. Volume: 205,440 acre/feet.
5. Mean hydraulic retention time: 268 days.
B. Tributary and Outlet:
(See Appendix A for flow data)
1. Tributaries -
Name Drainage area* Mean flow*
Lake Irving outlet 2
(Mississippi River) 584.0 mi 366.3 cfs
Minor tributaries & 2
immediate drainage - 35.5 ml 19.5 cfs
Totals 619.5 mi 2 385.8 cfs
2. Outlet -
Mississippi River 630.0 mi 2 ** 385.8 cfs**
C. Precipitation***:
1. Year of sampling: 22.2 inches.
2. Mean annual: 21.1 inches.
t DNR lake survey map (1967); mean depth by random-dot method.
* Drainage areas are accurate within ±5%; mean daily flows are accurate
within ±10%; and ungaged flows ar accurate within ±10 to 25% for
drainage areas greater than 10 mi ’.
** Includes area of lake; outlet flow adjusted to equal sum of inflows.
See Working Paper No. 1, “Survey Methods”.
Rc9ea h Cc Xe
? 35th Street
0
Corvail1 , Q oqQfl
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4
III. LAKE WATER QUALITY SUMMARY
Lake Bemidji, one of a chain of upper Mississippi River lakes (see
map, page vi), was sampled three times during the open-water season of
1972 by means of a pontoon-equipped Huey helicopter. Each time, samples
for physical and chemical parameters were collected from two stations on
the lake and from a number of depths at each station (see map, page vii).
During each visit, a single depth—integrated (15 feet to surface) sample
was composited from the two stations for phytoplankton identification and
enumeration; and during the last visit, a single five-gallon depth-integrated
sample was composited for algal assays. Also each time, a depth-integrated
sample was collected from each of the stations for chlorophyll a analysis.
The maximum depths sampled were 48 feet at station 1 and 46 feet at station
2.
The results obtained are presented in full in Appendix B, and the data
for the fall sampling period, when the lake was essentially well—mixed,
are sumarized below. Note, however, the Secchi disc summary is based on
all values.
For differences in the various parameters at the other sampling times,
refer to Appendix B.
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5
A. Physical and chemical characteristics:
FALL VALUES
(10/21/ 72)
Parameter Minimum Mean Median Maximum
Temperature (Cent.) 6.1 6.8 6.8 7.4
Dissolved oxygen (mg/i) 10.0 10.7 10.8 11.1
Conductivity (pmhos) 290 295 295 300
pH (units) 8.4 8.4 8.4 8.4
Alkalinity (mg/i) 154 157 156 161
Total P (mg/i) 0.037 0.052 0.050 0.067
Dissolved P (mg/i) 0.028 0.040 0.038 0.055
NO + NO (mg/i) 0.020 0.028 0.030 0.040
Am onia mg/1) 0.030 0.046 0.050 0.060
ALL VALUES
Secchi disc (inches) 69 85 86 100
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6
B. Biological characteristics:
1. Phytoplankton —
Sampling Dominant Number
Date Genera per ml
07/11/72 1. MicrocystiS 2,803
2. Anabaena 940
3. Dinobryon 723
4. Melosira 163
5. Fragilaria 90
Other genera 543
Total 5,262
09/08/72 1. Microcystis 2,355
2. Lyngbya 2,283
3. Anabaena 1,377
4. Dinobryon 399
5. Flagellates 217
Other genera 1 ,231
Total 7,862
10/21/72 1. Melosira 1,747
2. P nabaena 723
3. Fragilaria 602
4. StephanodiscuS 422
5. ChroococcuS 346
Other genera 1 ,52l
Total 5,361
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7
2. Chlorophyll a -
(Because of instrumentation problems during the 1972 sampling,
the following values may be in error by plus or minus 20 percent.)
Sampling Station Chlorophyll a
Date Number ( pg/i )
07/11/72 01 9.2
02 8.3
09/08/72 01
02
10/21/72 01
02
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked —
Ortho P Inorganic N
___________ Conc. (mg/i) Conc. (mg/i ) _____________
0.020 0.047
0.026 0.047
0.032 0.047
0.044 0.047
0.080 0.047
0.080 10.047
0.020 10.047
2. Discussion —
The controi yield of the assay alga, Selenastrum capri—
cornutum , indicates that the potential primary productivity
of Lake Bemidji was moderate at the time the sample was
collected. Also, the lack of significant change in yield
with increasing increments of orthophosphorus, until nitro-
gen was also added, shows that the lake was nitrogen limited.
Note the increase in yield when only nitrogen was added.
Spike (mg/i )
Control
0.006 P
0.012 P
0.024 P
0.060 P
0.060 P + 10.0 N
10.0 N
6.6
6.9
8.9
17.0
Maximum yield
( mg/i-dry wt. )
1.3
1.3
1.2
1.0
1.4
37.1
7.8
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8
The lake data indicate nitrogen limitation at the other
sampling times as well (N/P ratios were 9/1 or less).
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9
IV. NUTRIENT LOADINGS
(See Appendix C for all data)
For the determination of nutrient loadings, the Minnesota National
Guard collected monthly near-surface grab samples from each of the tribu-
tary sites indicated on the map (page vii), except for the high runoff
months of April and May when extra samples were collected. Sampling was
begun in October, 1972, and was completed in September, 1973.
Through an interagency agreement, stream flow estimates for the year
of sampling and a “normalized” or average year were provided by the
Minnesota District Office of the U.S. Geological Survey for the tributary
sites nearest the lake.
In this report, nutrient loads for sampled tributaries were determined
by using a modification of a U.S. Geological Survey computer program for
calculating stream loadings*. Nutrient loadings for unsampled “minor
tributaries and immediate drainage” (“ZZ” of U.S.G.S.) were estimated by
using the means of the nutrient loads, in lbs/mi 2 /year, in streams tribu-
tary to nearby Leech Lake at stations 2746C-i , D-1 , F-l, G-l , H—i , and
J-l and multiplying the means by the ZZ area in mi 2 .
A. Waste Sources:
1. Known municipal - None
2. Known industrial - None
* See Working Paper No. 1.
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10
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs —
lbs P1 % of
Source yr total
a. Tributaries (non-point load) -
Lake Irving outlet
(Mississippi River) 23,120 91.4
b. Minor tributaries & immediate
drainage (non-point load) - 990 3.9
c. Known municipal - None - -
d. Septic tanks* - 190 0.8
e. Known industrial - None -
f. Direct precipitation** - 1,000 3.9
Total 25,300 100.0
2. Outputs -
Lake outlet - Mississippi River 16,290
3. Net annual P accumulation - 9,010 pounds
* Estimated 777 persons residing on lake shore (Holt, et al., 1971);
see Working Paper No. 1.
** See Working Paper No. 1.
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11
C. Annual Total Nitrogen Loading - Average Year:
1. Inputs -
lbsN/ %of
Source yr total
a. Tributaries (non-point load) -
Lake Irving outlet
(Mississippi River) 653,760 85.2
b. Minor tributaries & immediate
drainage (non—point load) -— 44,410 5.8
c. Known municipal - None -
d. Septic tanks* - 7,300 1.0
e. Known Industrial - None -
f. Direct precipitation** - 61,850 8.0
Total 767,320 100.0
2. Outputs -
Lake outlet — Mississippi River 575,490
3. Net annual N accumulation - 191,830 pounds
* Estimated 777 persons residing on lake shore (Holt, et al., 1971);
see Working Paper No. 1.
** See Working Paper No. 1.
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12
D. Mean Annual Non-point Nutrient Export by Subdrainage Area:
Tributary lbs P/mi 2 /yr lbs N/mi 2 /yr N/P Ratio
Lake Irving outlet
(Mississippi River) 40 1,120 28/1
E. Yearly Loading Rates:
In the following table, the existing phosphorus loading
rates are compared to those proposed by Vollenweider (in press).
Essentially, his dangerous” rate is the rate at which the
receiving waters would become eutrophic or remain eutrophic;
his “permissible” rate is that which would result in the
receiving water remaining oligotrophic or becoming oligo—
trophic if morphometry permitted. A mesotrophic rate would
be considered one between “dangerous” and “permissible”.
Total Phosphorus Total Nitrogen
Units Total Accumulated Total Accumulated
lbs/acr /yr 3.9 1.4 119.5 29.9
grams/rn /yr 0.44 0.16 13.4 3.3
Vollenweider loading rates for phosphorus
(g/m 2 /yr) based on mean depth and mean
hydraulic retention time of Lake Bemidji:
‘Dangerous” (eutrophic rate) 0.70
“Permissible” (oligotrophic rate) 0.35
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13
V. LITERATURE REVIEWED
Anonymous, 1948. Lake survey report, Lake Bemidji, Beltrami County.
MN Dept. Nat. Resources, Minneapolis.
Bonnema, Kenneth, and William G. Johnson, 1972. Control of aquatic
vegetation, algae, leeches, and swimmer’s itch. MN Dept. Nat.
Resources, Minneapolis.
Holt, Charles S., Roger A. Schulz, and Curtis M. Hadland; 1971. Patterns
of lakeshore usage around Lake Bemidji. Jour. Minn. Acad. Sd.,
V. 37, Nos. 2 and 3.
Hoekstra, Donald J., 1968. Nitrogen and phosphorus analysis of six
Mississippi headwater lakes. MS, Limnology Inst., Bemidji State
College, Bemidji.
Schilling, Joel, 1974. Personal communication (lake map). MPCA,
Minneapolis.
Vollenweider, Richard A., (in press). Input-output models. Schweiz.
A. Hydrol.
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VII. APPENDICES
APPENDIX A
TRIBUTARY FLOW DATA
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TPIA1JTAPY FLOW INFORMATION FOM MINNESOTA
10/30/74
LAKE CODE 7CI
HEMIOJI LAKE
TOTAL OPAINAGE APEA O LAKE K30.00
51JR-DPAINAGE NOPMALIZED FLOW5
TPIPUTAPY APEA JAN FF9 MAP APP MAY JUN JUL AUG
504.00 290.00 163.00 ?98.00 757.00 763.00 524.00 334.00 263.00 422.00 176.00 138.00 272.00 366.30
630.00 ?7M.01 362.09 ?9?.89 835.25 816.25 560.03 356.43 280.00 446.83 185.70 147.94 276.00 385.86
45.50 8.37 5.04 12.40 49.80 49.40 40.60 19.20 8.95 15.60 9.47 6.46 8.82 39.53
TOTAL D A1NAGE APEA OF LAKE =
SUM OF SUP—1)PAINAGE AREAS =
SUMMARY
10 7? 160.00
II 7 ’ 131.00
12 72 409.00
I 71 308.00
2 73 114.00
1 73 814.00
4 73 236.00
S 73 230.00
K 73 191.00
7 73 145.00
B 73 2 OA.00
0 73 300.00
10 7’ 172.00
I I 72 140.00
12 72 ‘18.00
I 73 303.00
7 73 174.00
1 72 819.00
4 73 ?0S.00
5 73 203.00
4 73 190.00
7 71 180.00
9 73 200.00
9 73 500.00
10 7? 8.67
I l 7 6.10
1? 7? 13.30
I 73 9.21
7 73 5.39
1 13 13.90
4 73 18.90
5 73 18.40
6 73 IS.30
7 73 11.40
9 7 16.20
9 73 175.00
14 211.00
5 131.00
10 397.00
20 268.00
38 174.00
17 2440.00
1 250.00
19 209.00
N 129.00
I I 206.00
16 350.00
14 227.00
5 140.00
10 405.00
20 264.00
19 174.00
17 2460.00
1 217.00
19 195.00
8 160.00
II 200.00
lb 580.00
14 11.00
5 6.30
10 13.00
20 8.00
18 5.40
Il 302.00
20.00
39 17.00
8 30.30
11 16.00
lb 203.00
27C 343
PlC IA?
27(117
MEAN MONTHLY FLOWS AND DAILY FLOWS
TPIHtJIAPY MONTH
SEP OCT NOV DEC MEAN
YEAR MEAN FLOW DAY
630.00 TOTAL
FLOW
IN
629.50 TOTAL
FLOW
OUT
=
4622.39
FLOW DAY
?7C1A 1
?7C1 A?
PlC Ill
FLOW DAY FLOW
14 217.00
1 389.00
34 17.00
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APPENDIX B
PHYSICAL and CHEMICAL DATA
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STOPET RETRIEVAL DATE 74/10/30
27C101
47 28 40.0 094 51 42.0
LAKE BEMIDJI
27 MINNESOTA
11EPALES 2111202
3 0045 FEET DEPTH
00010 00300 00077 00094 00400 00410 00630 00610 00665 00666
DATE TIME DEPTH WATER DO TRANSP CNDUCTVY PH T ALK NO2 NO3 NH3—N PHOS—TOT PHOS—DIS
FROM OF TEMP SECCHI FIELD CACO3 N—TOTAL TOTAL
TO DAY FEET CENT MG/L INCHES MICROHHO St.) MG/L MG/C MG/L MG/L P MGIL p
72/07/11 10 00 0000 87 360 8.30 171 0.040 0.060 0.024 0.00$
10 00 0004 20.9 9.4 350 8.30 174 0.040 0.060 0.019 0.10$
10 00 0015 20.0 8.2 350 8.20 175 0.040 0.050 0.020 0.01$
- 10 00 0040 11.1 0.2 300 7.40 183 0.040 0.370 0.093 0.067
7?/09/08 11 25 0000 84 310 8.10 156 0.040 0.060 0.032 0.1 16
11 25 0004 17.5 7.6 305 8.05 156 0.020 0.040 0.02 ? 0. 512
11 25 0015 17.3 6.1 305 8.00 157 0.030 0.070 0.028 9.017
11 25 0022 17.2 7.3 290 8.00 158 0.050 0.130 0.028 1. 116
II 25 0030 17.2 6.9 310 7.95 157 0.040 0.130 0.S36 l.I$1
11 25 0039 16.4 5.0 310 7.80 158 0.030 0.24$ 0.051 •.S31
11 25 0048 12.7 0.3 355 7.25 182 0.090 0.130 Qr 4
72/10/21 15 20 0000 72 300 8.40 155 0.040 0.060 I.
15 20 0004 6.8 11.1 295 8.40 157 0.020 0.041 0.000 5..
15 20 0015 6.5 10.8 290 8.40 157 0.020 0.040 0.003 I.
15 20 0022 6.5 10.8 290 8.40 161 0.030 0.050 0.037 1.111
15 20 0030 6.5 10.8 300 8.40 160 0.030 0.050 0.046 S.S
15 20 0041 6.4 10.6 300 8.40 160 0.030 0.060 0.155 SIN
32217
DATE TIME DEPTH CHLPPHYL
FROM OF A
TO DAY FEET IJG/L
72/07/lI 10 00 0000 9.2J
72/09/08 11 25 0000 6.6J
77/10/21 15 20 0000 8.RJ
J* VALUE KNOWN TO BE IN ERROR
-------
STi’ -T rr_ii I . .T 1 ./I
27(107
1 00.0 094 51 10.0
LAKE MIi)JI
27 M IN 1WSOTa
1 IE’ALES 2111202
0019 FEET DEPTH
1
•
7/
00410
OO ,30
•
r,
c
. -‘
I
AL (
NO2. N03
J .-43—N
P1-sOS—TOT
‘ -‘
- (--‘I
r It- 1 )
CACO
t J—T0TAL
TOTAL
1
. ./
I
.
4I) r-i1
MC,/L
M(.,/L
MG/L
lG/L P
P46/L
r)ATE A.-
rL) ’ I
I) I)A1 F’- I
77/ 7/II 1 ) “)
1-s ) ‘ -)r
Ifl l(i 5.’) I -
It. - -sr ,
72/-IO II ‘• 1 “fl”.S
I I ‘ • - fl .’—.
IT 1
II •
1) )
72/11/21 14 “t .:n
I-. ,•
14 • ‘ Ii
I L. ‘I .’!
1L.
f.’) —,
I—. 1 (
‘ ) ‘I IT • ‘1-4
1 ) ,A
72/ 17/ I V
I!
72/ I )/2, -
)
‘ 4.4’
174
‘I . ’
.
15’
.4u
171
0.040
0.050
0.014
0.008
2’ •
•
14
. .c
172
0.030
0.050
0.015
0.006
II •
I •
1 si3
7.4()
. 0
176
149
0.07( 5
0.020
0.140
0.080
0.030
0.025
0.021
0.011
I’. .
7.’
Ifl3
.? 1
1L 9
0.0?0
0.070
0.025
0.011
I7.
— .-‘
100
2.15
15 ’ )
0.030
0.080
0.021
0.010
7•
7. ’-
0C
s ’.15
149
0.010
0.080
0.021
0.010
7..
7. - ’
I
‘1fl’
1 u.
- .15
‘.-.e
149
155
0.020
0.020
0.070
0.030
0.020
0.067
0.009
0.055
P. *
I .
0’
‘ •4 5)
154
0.020
0.030
0.041
0.028
7.-
I •
“-)C ’
.4 (
154
0.030
0.040
0.063
0.054
)
1.-
15P
0.030
0.040
0.066
0.051
7.
1 .7
i.43
155
0.030
0.050
0.054
0.042
7.
1’ • 7
-,.40
156
0.040
0.060
0.048
1’ .
41(
c ’.40
1:,5
0.030
0.050
0.040
0.028
‘I
‘ I
J* V LlJ- r0)4rI 1) — 7 j ) - .
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APPENDIX C
TRIBUTARY DATA
-------
ST’)P T PETPTFVAL I)#T Th/l(’/J O
?7CLA1 LS27CIA1
47 28 00.0 094 52 30.0
MISSISSIPPI IVEk
27 7.5 BEMIDJI WEST
1/LAPSE r3FP4IDJI
MiRI)C, .5 M I UPSTREAM
1 1EPALES
DATE
F POP’
TO
T I F
OF
DAY
(‘GE 30
N93-N
TOTAL
00671
P’-iOS-DIS
OR I HO
MG/L P
4
00665
PHOS—TOT
MG/L ‘
LAKE IRVING
2111204
0000 FEET
0ci’ 3J
DEPTH O’ MO3
N— TOT AL
FEET MG/L
0 .070
0.0?5
‘j. O lS
C
‘. 115
O • 170
C .os
• 0 1 1
0 • 0 I ‘3 PS
0.010K
0.0 lOPS
).O 10K
0 • 0 7
7?/I0/ 14
72/11/05 10 10
7?/12/l0 10 05
71/01/20 09 10
73/OP/IP I? 00
71/01/17 0 0
71/04/01 11 30
73/04/i’ 09 00
7l/05/I 09 40
73/06/03 09 15
71/07/OR 08 35
73/OR/il 08 15
71/0 /1 ’ 09 10
DEPTH
oo c
TOT KJEL
N
MG/I
0.610
0 .4R0
O • 540
0 • 480
0 •
O • L Ř
0.580
7.600
0 .540
O • c)q
1.051)
1 • 760
0.044
0.005K
0.030
0.026
0.016
(1.024
0.019
0.005K
0.012
0.130
0.009
0.015
0.154
0.011
0.025
0.115
0.009
0.030
0.028
0.008
0.040
9.03u
0.006
0.032
O. 005 P S
0.010
0.035
0.010
0.006
0.030
0.011
0.011
0.055
0.02S
0.015
0.070
0.056
0.018
0.045
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
ST’)kFT ETPJ VAL
?TC1NI LS27C IN1
47 29 30.0 09” 50 00.0
MISSISSIPPI P1VE
?7 7.5 BEMIDJI EAST
0/LAKE BEMIDJI
HET N BEMIDJI SIP AND PP TRESTLE
1IEPALES 2111204
4 0000 FEET DEPTH
006?5 00610 00671 00665
flATE TIME DEPTH N07 N03 TOT KJEL ‘JH3—N P iOS—D1S PHOS—TOT
FP )M OF J—T’JTAl_ N TUTAI O THO
TO DAY F FT M(,/L ‘ /L .iC,/L MG/L P MG/L P
72/12/101020 3.0 ’ 0.720 0.032 0.009 0.019
73/0I/?0 00 45 0.01.) 0.6 9 O.u3? 0.005K 0.005K
7 /07/1 1? 10 ( .019 0.560 0.030 0.005 1 < 0.010
71/03/17 01 5’ 0.07’ 1.1 70 0.05R 0.00 51< 0.020
71/04/01 11 45 3. Oi Oc 0.540 0.009 0.005K 0.030
71/04/14 09 05 0.016 0.5 O 0.00 51< 0.0051< 0.020
71/05/19 09 0 0.010K 0.500 0.0051< 0.005K 0.030
71/06/01 0915 0.010K 7.103 iJ.026 0 .005K 0.025
71/07/0 0965 0.0131< 0.6 1(J 0.01 ? 0.009 0.020
7 3/OR/ Il O 20 0.025 0.620 0.031 0.0051< 0.025
71/09/1 09 40 0.013 0.’60 3.025 0.017 0.045
K VALUE KNOWN TO BE LESS
THAN INDICATED
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