U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
:V\LfE»L LAKE
POPE COIMY
EPA REGION V
UORKING PAPER ilo, 109
PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY
An Associate Laboratory of the
NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON
and
NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA
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REPORT
ON
'VMJEEAL LAKE
POPE COUNTY
,'ILflESJTA
EPA REGION V
PAPER iJo, 1D9
WITH THE COOPERATION OF THE
MINNESOTA POLLUTION CONTROL AGENCY
AND THE
,'llNNEoOTA NATIONAL GUARD
OCTOBER, 1974
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CONTENTS
Page
Fnreword ii
List of Minnesota Study Lakes iv, v
Lake and Drainage Area Map Vi
S e Ct ion s
1. Conclusions
II. Lake and Drainage Basin Characteristics 3
III. Lake Water Quality Sumary 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
reservoirs.
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 [ lO6 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. 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
The staff of the National Eutrophication Survey (Office of
Research & Development, U. S. Environmental Protection Agency)
expresses sincere appreciation to the Minnesota 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
Al bert Lea
Andrusia
Badger
Bart] ett
Bear
Bemidji
Big
Big Stone
Birch
Bi ackduck
Bi ackhoof
Bu dd
Buffalo
Cal houn
Carl os
Carri gan
Cass
Cl ea iater
Co k a to
Cr an berry
Oar] inq
El bow
Emb a r as s
Fall
Forest
Green
Gui 1
Heron
Leech
Le I-{omme Dieu
Lily
Little
Lost
COUNTY
Freeborn
Bel trami
Po 1 k
Koochiching
Freeborn
Beltrami
Stearns
Big Stone, MN; Roberts,
Grant, SD
Cass
Be] trami
Crow Wing
Mart in
Wright
Hennepi n
Do u 91 as
Wright
Bel trami , Cass
Wright, Stearns
Wright
Crow Wing
Dougl as
St. Louis
St. Louis
Lake
Washington
Kandiyoh i
Ca s s
Jackson
Ca s S
Douglas
Blue Earth
Grant
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, rIN; Douglas, WI
Superior Bay St. Louis, MN; Douglas, WI
Swan Itasca
Trace Todd
Trout Itasca
Wagonga Kandiyohi
Walimark Chisago
White Bear Washington
Winona Douglas
Wolf Beltrami, Hubbard
Woodcock Kandiyohi
Zumbro Olrnstead, Wabasha
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v i
9532’
—4542’
c
--
...f .
— 45•4)
J
N
.2
(
1
S
Map Location
\ —
9530
: : A1 ... .
¶ ,:
-
)
)
C’
S
-> .
)
(
MALMEDAL LAKE
0 Tributary Sampling Site
X Lake Sampling Site
Sewage Treatment Facility
IDirect Drainage Area Limits
Indirect Drainage Area Mi.
Scale
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MALMEDAL LAKE
STORET O. 2752
I. CONCLUSIONS
A. Tropnic Condition:
It is concluded that flalmedal Lake is eutrophic. Survey
limnologists noted the prevalence of rooted aquatic vegetation
and extreme turbidity.
Uf the 60 Minnesota lakes sampled in the fall iheti essen-
tially all were well-mixed, 33 had less rican total pnosphorus
and 41 had less mean inorganic nitrogen. For all 80 lakes
sampled, 84% had greater transparency, and 75% had less nean
chlorophyll a.
B. ate-Limiting 1utrient:
The algal assay results sho i that Malmedal Lake was phosphorus
limited at the time the sample was collected, but the lake data
indicate nitrogen limitation in July and Septenber, 1972.
C. Nutrient Controllability:
Because of the estimations and assumptions nade in the
assessment of loadi 1 ig rates, it is not realistic to riake
further estimations and assumptions as to loading rata or
nutrient controllability, particularly in view of the fact
that during the sampi ing year the amount of phosphorus riea-
sured leaving the lake was 1.5 times the estimated total load
to the lake.
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2
It appears there may nave Leen sorie mislabeled samples from
the tributaries. The mean total .osphorus in the inlet stream,
below the Lowry wastewater pond was about 0.19 mg/i but tile rtiean
total phosphorus in t ie outlet of the lake was over 0.25 rng/l
(note that the total P concentrati n in the October, 1972, outlet
sample was nearly two times the P concentration measured in the
lake at about the same time).
Now, phosphorus wash-out could have occurred, particularly if
point-source contributions had been reduced or eliminated recently;
however, as far as is known, no such reduction occurred.
A need for a more detailed study of the 1almedal Lake system
is indicated.
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II. LAKE AND DRAINAGE BASIN CHARACTERISTICS
A. Lake Morphometry*:
1. Surface area: 195 acres.
2. Mean depth: 6** feet.
3. Maximum depth: 8 feet.
4. Volume: 1,170 acre/feet.
5. Mean hydraulic retention tine: 1.3 years.
B. Tributary and Outlet:
(See Appendix A for flow data)
1. Tributaries -
Name Drainage area [lean flow
County Ditch No. 7 4.2 mi2 O.G cfs
Minor tributaries & 2
immediate drainage - 3.8 mi 0.6 cfs
Totals 8.0 mi2 1.2 cfs
2. Outlet -
Unnamed Stream 8.3 mi 1.2 cfs
C. Precipitation :
1. Year of sampling: 24.8 inches.
2. ilean annual: 17.9 inches.
* DNR lake survey map (1971).
** Anonymous, 1972.
t Drainage areas are accurate within ±5%; mean daily flows are accurate
within ±10%; and ungaged flows are accurate within ±10 to 25% for drainage
areas greater than 10 mi2.
tt Includes area of lake.
ttt See Working Paper No. 1, "Survey Methods".
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4
III. LAKE tIATER QUALITY SUMMARY
Flalmedal Lake ias 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
depths at one station on the lake (see map, page vi). During each
visit, a single depth-integrated (near bottom to surface) sample was
collected for phytoplankton identification and enumeration; and during
the last visit, a single five—gallon depth—integrated sample was col—
1 ected for algal assays. Also each time, a depth-integrated sample
was collected for cMorophyll a analysis. The maximun depth sampled
was 4 feet.
The results obtained are presented in full in Appendix 3, and the
data for the fall sampl ing period, when the lake was essentially well -
mixed, are summarized 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 ppendix B.
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5
A. Physical and chemical characteristics:
FALL VALUES
(10/25/72)
Parameter Minimum Ilean Median Maximum
Temperature (Cent.) 4.4 4.4 4.4 4.4
Dissolved oxygen (mg/i) 12.4 12.4 12.4 12.4
Conductivity (ijmhos) 600 600 600 600
pH (units) 8.7 8.7 8.7 8.7
Alkalinity (mg/i) 180 180 180 180
Total P (mg/l) 0.060 0.062 0.062 0.065
Dissolved P (mg/l) 0.021 0.023 0.023 0.025
NO + NO (mg/i) 0.100 0.105 0.105 0.110
Am onia mg/1) 0.330 0.330 0.330 0.330
ALL VALUES
Secchi disc (inches) 13 15 15 16
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6
1. Pnytoplankton -
Sanipling
Date
07/06/72
Domi nant
Genera
1 . 1icrocystis
2. Oscillatoria
3. Closterium
4. ilelosira
5. Cyclotella
Other genera
£1 umber
per ml
2,651
2,440
2 , 1 99
1 ,566
1 ,084
6,385
1 6 ,325
1 . Melosira
2. ilicrocystis
3. Lyngbya
4. Oscillatoria
5. Flagellates
Other genera
1. Oscillatoria
2. Anabaena
3. 1licrocystis
4. Dinobryon
5. Lyngbya
Other genera
16,061
11,364
4,848
4,545
4,394
16,212
57,424
1 ,973
1 ,732
1 ,611
422
271
2,093
B. Biological characteristics:
Total
09/01/ 72
10/25/72
Total
Total 8,102
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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 (i.ig/fl_______
07/06/ 72 01 49.8
09/01/72 01 o3.5
10/25/72 01 9.7
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked -
Ortho P Inorganic N flaximum yield
pike (mg/l) Conc. (mg/i) Conc. (mg/i) ( mg/i—dry wt.. )
Control 0.014 0.376 7.4
0.005 P 0.019 0.376 8.5
0.010 P 0.024 0.376 9.2
0.020 p 0.034 0.376 9.3
0.050 p 0.064 0.376 9.9
0.050 p ÷ 10.0 N 0.064 10.376 29.8
10.0 N 0.014 10.376 6.2
2. Discussion —
The control yield of the assay alga, Selenastrum pri-
cornutum , indicates that Ilalmedal Lake had a high level of
potential primary productivity at the time the sample ‘ ias
collected. Also, the increased yields with increased levels
of orthophosphorus (up to about 0.024 mg/i) show that the
lake was phosphorus limited. Note that addition of only
nitrogen resulted in a yield not significantly different
from the control yield.
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8
The lake data also indicate phosphorus limitation in
October (N/P ratio of 19/1) but nitrogen limitation in
July and September (N/P ratios of 4/1 and 10/1 , respectively).
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9
IV. NUTRIENT LOADINGS
(See Appendix C for 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 vi), except for the high runoff
months of April and May, when two samples were collected, and the colder
months of the year when ice cover prevented sampling. 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 Minne-
sota District Office of the U.S. Geological Survey for the tributary sites
nearest the lake.
In this report, nutrient loads for sampled tributaries were calculated
using mean concentrations and the mean monthly flows for the sampling year .
Nutrient loadings for unsampled “minor tributaries and irrniediate drain-
age” (“ZZ” of U.S.G.S.) were estimated by using the means of the nutrient
loads, in ibs/mi 2 /year, in Fish and three unnamed creeks tributary to nearby
Big Stone Lake (see Working Paper No. 85) at stations 2709G-l, D-i, E—l,
and F-i (19 lbs P and 369 lbs N/m1 2 /yr) and multiplying the means by the
Malmedal Lake ZZ area in mi 2 .
During the sampling year, the phosphorus load measured in County
Ditch No. 7 at station B-i was 380 lbs. This is less than the amount
that would have been estimated for the Village of Lowry on a per—capita
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10
basis (1970 Census = 257 x 2.5 lbs P/capita/yr = 640 lbs P/yr.) Therefore,
in the loading tables that follow, the phosphorus load attributed to Lowry
is the load measured at station B-i minus the estimated non-point source
load of 19 lbs P/mi 2 /yr (4.2 mi 2 x 19 = 80 ibs).
A. Waste Sources:
1 . Known municipal -
Pop. Mean Receiving
Name Served Treatment Flow (mgd) Water
Lowry 257* Pond 0.026** County Ditch #7
2. Known industrial — None
* 1970 Census.
** Estimated at 100 gal/capita/day.
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11
B. Annual Total Phosphorus Loading - Sampling Year :
1. Inputs —
lbs P / % of
Source yr total
a. Tributaries (non-point load) -
County Ditch No. 7 80 16.7
b. Minor tributaries immediate
drainage (non-point load) — 70 14.6
c. Known municipal -
Lowry 300 62.5
d. Septic tanks - None known
e. Known industrial - None
f. Direct precipitation* - 30 6.2
Total 480 100.0
2. Outputs —
Lake outlet 1 ,200
3. Net annual P loss - 720 pounds
* See Working Paper No. 1.
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12
C. Annual Total Nitrogen Loading - Sampling Year :
1 . Inputs —
lbs NI % of
Source yr _____
a. Tributaries (non—point load) —
County Ditch No. 7 4,270 51.2
b. Minor tributaries & imediate
drainage (non—point load) — 1,400 14.9
c. Known municipal -
Lowry 930 11.2
d. Septic tanks - None known
e. Known industrial — None — -
f. Direct precipitation* - 1,890 22.7
Total 8,490 100.0
2. Outputs —
Lake outlet 7,350
3. Net annual N accumulation - 1 ,140 pounds
* See Working Paper No. 1.
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13
V. LITERATURE REVIEWED
Anonymous, 1972. Survey questionnaire. MPCA, Minneapolis.
Anonymous, 1973. Wastewater disposal facilities inventory. MPCA,
Minneapol is.
Schilling, Joel, 1974. Personal comunication (lake map). riPci,
f•linneapol is.
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VII. APPENDICES
APPENDIX A
TRIBUTARY FLOW DATA
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IPIMiT6wY FLC)W I.NFO 1MAu10N FO 105r’,OTA 10/30/74
LA F row ‘c ‘AL’IF”AI LAV
TOTAL fl2AI’OAGE A4f A OF LA Y
,OPI-4AL I/ F) FL ()
T IWUTAPY APFA JA) F!r ’ A”H MAY JO JUL AU ), SEP OCT NOV DEC MEAN
2 752 43 4. 31 u.. ‘ 3.”l 0.13 1.66 1.24 1.1 ’ 0.7-, 0.35 0.70 0.27 0.15 0.14 0.62
?75?CI 0.1w 1.12 3.’.9 2.50 7 I ) 1.53 0.15 1.34 0.56 0.35 0.26 1.24
775271 4 32 0..,’- ‘.‘I J•6Q 1.6? 1.21 1.15 0.17 0.38 0.13 0.28 0.17 0.14 0.62
S J’.14-4 A’. Y
TOTAL DOAINA(,E APLA OF LAKE = €‘.29 TOTAL FLOW IN 14.8 ?
Stiw OF S JH_1’L)AIrJAr.F APEAS = 8.29 TOTAL FLOW OUT = 34. 143
MEAN MONTrILY FLOWS At) ’) uAILY FLOWS
TPI.-)UTAQY IONT- YFA).1 ‘IFI’J FLOW nAY FLOW OAY FL)’W DAY FLOW
I I 1? 0.13 IS 0. 80
I i 7 ? (4.44 10 0.60
I , 7? 0.” = 0.0
I 13 O.? 7 0.0
73 O. ’ 4 0.20
3 13 1.2° lu 2.10
4 1 1 1.61 IS 1.60 30 1.20
5 7 ’ 1.36 ?C 0.90 30 I. ’O
6 13 0.4-1 ii 0.70
7 73 0.’3 I i 0.16
73 0.”. 7 0. 14
1 3 (‘.‘ 5 10 0.45
7 75?rI 10 7 ? 1.07 1 2.00
1 1 77 I. ’ ? I C 1.60
I 77 I. ’ 1. 1 40
73 r c c 7 0.60
7 13 0.77 4 0.30
1 73 l— -)3 I ” 4.50
4 f l “.‘6 16 4.10 30 3.10
5 7 ’ 3.wl 20 2.40 30 3.6 )
74 1. 1 6 II
7 /3 u.” ) I l 0 .40
O 74 C.h4 7 0.47
I. .-’ 30 1.10
I ) , 7 ’ 0.77 1-’
II 7 ’ 0.’.” 3)’ -0.50
I ’ 1 ’ M
f l C. ”. 7 0.30
7 0.34- 4 0.20
1 75 1.7 ’ II 1.80
4 13 I. ” ’ IS l.W0 30 1.10
5 7 1.4C 2 1.0) 30 1.1),
6 1 ’ “. ‘ - II 5.7’)
1 1 3 .7 , I l 0.16
7 ,.-“. 7 u.I
73 )) .7 It, 4.67
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APPENDIX B
PHYSICAL and CHEMICAL DATA
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STO ET RFTPIEVAL DATE 74/10/30
DATE
FROM
TO
TIME DEPT 1
OF
DAY FEET
32217
Cp-lL PHYL
A
IJG/L
275201
45 40 25.0 095 31 38.0
MAL’IEDAL LAKE
27 MINNESOTA
1 IEPALES
3
72/07/OA
72/09/03
72/ 10/25
16 20 0000
15 10 0000
14 30 0000
49. 8J
63. SJ
9. 7J
2111202
0006 FEET DEPTH
00010
00300
00077
00094
00400
00410
00630
00610
00665
00666
DATE
TIME
DEPTM
WATER
DO
TRANSP
CNDLJCTVY
PH
1 ALK
N02 NO3
NH3—N
PHOS—TOT
PHOS—DIS
FROM
OF
TEMP
SECCHI
FIELD
CACO3
N—TOTAL
TOTAL
TO
DAY
FEET
CENT
MG/I
INCMES
MICROMHO
SU
MG/L
MG/L
MG/L
MG/L P
MG/I P
72/07/06
36 ?0 0000
21.0
11.0
16
520
8.10
188
0.040
0.060
0.147
0.027
16 20 000?
23.0
5.4
520
8.00
193
0.040
0.120
0.209
0.034
72/09/01
15 10 0000
20.0
13
550
8.40
157
0.140
0.220
0.134
0.040
15 10 0004
19.9
11.7
575
8.30
155
0.150
0.280
0.117
0.038
72/10/25
14 30 0000
600
8.70
180
0.110
0.330
0.060
0.021
14 30 0004
4.4
J7 4
600
8.70
180
0.100
0.330
0.065
0.025
J VALUF KNOWN TO 13E IN ERROR
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APPENDIX C
TRIBUTARY and WASTEWATER
TREATMENT PLANT DATA
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ST’)QFT FT- T VA1 •‘Ar. 7 / ) / ‘
LS275 7 1
.5 ‘+1 00.0 0 5 32 00.0
Str 1 i)r NG TO SWAMP NW EDGE OF LK
7.5 LO lRY
T/MALMEOAL LAKE
C ) HWY 3 XING -WLO LOwRY STP
11r AL S 2)11204
0000 FEET DEPTH
OOfR5 0 ’ )0 OOf,71
DATE TIME DEPTH NO?&N03 TOT JEL NH3—N R iOS—DIS riO —TOT
FPOM OF N—TOTAL N TOTAL OPTHO
TD DAY FEET 1G/L 1r,/L Mf /L P MG/L
7?/10/15 09 53 1.500 1.555 0.071 0.044 0.0b4
72/11/10 11 17 1.370 l.c40 0. OOM 0.040
71/01/10 11 00 3.500 ?.40f, 0.1MG 0.370 3.413
73/04/15 11 05 1.700 7.200 .05f ’ 0.029 0.051
71/04/30 1? 30 .40O ?.510 0.06 0.026
71/05/20 1? 30 .400 p.100 0.024 0.027 0.040
71/05/30 12 30 ?.7 0 0 3.700 0.072 0.027 0.045
11/06/11 11 35 4.303 1.R )0 0.035 0.042 0.055
71/07/17 11 50 p.000 0.051 0.07
7i/o /io 150? .5’J0 4.400 .04? 0.105 1.u5U
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ST’) ET QE1PTEVAL r).!tTF 7./1u/3 0
?7 ?C1 LS?752C1
‘.5 ‘.0 30.0 0Q5 31 00.0
ST’ M ‘)RNG SWAMP AT E END OF LAKE
2? 7.5 LOWRY
T/MAL iFDAL LAKE
ST rIWY 114 2 M I S OF LOWRY
1IEPALES 2111204
4 0000 FEET DEPTH
fl O ’ .10 00 71 00f,f 5
)ATE Tp - ‘) T-I iO? ’O3 TOT PcJEL t1r43—N PrIOS—DIS h’JS-TOT
OF J—TflTAL N TOTAL IJPTH()
TO DAY F T rM/L ‘1’,L i ( /L iG/L P MG/L
72/10/15 IJQ 45 0.730 .(,50 0.370 0.014 .u15
7?/11/1 L I I’ “.15 ‘.f’O( ( 1.021 0.010 0.135
7 /flh/10 10 0 o.Th) 4.c O O 2.500 O.3 0 0,410
71/04/1 ii 00 O.0’.O 7.1 10 o.32e 0.017 0.140
73/04/30 1? ‘0 3.0 2 5 7.500 0.300 0.030 0.150
71/0S/2 ) 1? 20 Q ,fl27 3.400 t).736 0.0?R 0.13)
r /0c/3o 12 70 0.030 ?. 00 0.35( 0.030 0.137
71/0 /1L I’ 10 0.03’ 1.700 0.350 0.0S 0.145
71/07/17 11 445 7. 530 3.3)5 0.200 0.f 0
73/0 /07 11 40 C.01u 1 .f O” 1. 0 fl.?10 0.530
71/0 /10 14 5 3. - 10 3. 115 0.043 0.230
K VALUE KNOWN TO dE LESS
T9AN I(’JDICATFD
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