U.S. ENVIRONMENTAL PROTECTION AGENCY
               NATIONAL EUTROPHICATION SURVEY
                        WORKING PAPER SERIES
                                              REPORT
                                               ON
                                            SPIRIT LAKE
                                          DICKINSON COUNTY
                                               IOW
                                           EPAEGIONVII
                                        WORKING PAPER No, 506

     CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
                                 and
    ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
"WTG.P.O. 699-440

-------
                                   REPORT
                                     ON
                                SPIRIT LAKE
                              DICKINSON COUNTY
                                    IOWA
                               EPA REGION VII
                           WORKING PAPER No, 506
      WITH THE COOPERATION OF THE
IOWA DEPARTMENT OF ENVIRONMENTAL QUALITY
                AND THE
          IOWA NATIONAL GUARD
              AUGUST,  1976

-------
                                   CONTENTS

                                                               Page
  Foreword                                                      ii
  List of Iowa Study Lakes                                      iv
  Lake and Drainage Area Map                                     v

  Sections
  I.   Introduction                                               1
 II.   Conclusions                                                2
III.   Lake and Drainage Basin Characteristics                    4
 IV.   Lake Water Quality Summary                                 5
  V.   Literature Reviewed                                        9
 VI.   Appendices                                                10

-------
                                 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 freshwater 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 [§303(e)J, water
quality criteria/standards review [§303(c)L clean lakes [§314(a,b)],
and water quality monitoring [§106 and §305(b)] activities  mandated
by the Federal Water Pollution Control Act Amendments of 1972.

-------
                                 Ill
    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
freshwater 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 Iowa Department of Environ-
mental Quality for professional involvement, to the Iowa National
Guard for conducting the tributary sampling phase of the Survey,
and to those wastewater treatment plant operators who voluntarily
provided effluent samples and flow data.

    The staff of the Water Quality Division of the Department of
Environmental Quality provided invaluable lake documentation and
counsel during the Survey, reviewed the preliminary reports, and
provided critiques most useful in the preparation of this Working
Paper series.

    Major General Joseph G. May, the Adjutant General of Iowa,
and Project Officer Colonel Cleadeth P. Woods, who directed the
volunteer efforts of the Iowa National Guardsmen, are also grate-
fully acknowledged for their assistance to the Survey.

-------
                                    iv
LAKE NAME

Ahquabi
Big Creek Reservoir
Black Hawk
Clear
Darling
Lost Island
MacBride
Prairie Rose
Rathbun Reservoir
Red Rock Reservoir
Rock Creek
Silver
Spirit
Vi king
West Okoboji
NATIONAL EUTROPHICATION SURVEY

         STUDY LAKES

        STATE OF IOWA

                            COUNTY
                            Warren
                            Polk
                            Sac
                            Cerro Gordo
                            Washington
                            Clay, Palo Alto
                            Johnson
                            Shelby
                            Appanoose, Wayne
                            Marion
                            Jasper
                            Worth
                            Dickinson
                            Montgomery
                            Dickinson

-------
                                      MINNESOTA
                      WESTOKOBOJI LAKE
                           &   SPIRIT LAKE
                         X  Lake Sampling Site
                        0	 1234
                              1      2
                                Scale
 s Km.
3Mi.
                                                    43'3tf~
           4320—
9510
      9500'

-------
                               SPIRIT LAKE
                             STORE! NO. 1913

I.  INTRODUCTION*:
    Spirit Lake was included in the National Eutrophication Survey
as a water body of interest to the Iowa Department of Environmental
Quality.  Tributaries and nutrient sources were not sampled, and
this report relates only to the lake sampling data.
    Spirit Lake is one of a chain of natural lakes collectively known
as the Iowa Great Lakes.  Glacial in origin, the lake is quite shallow
but has the largest surface area of any of the natural  lakes in the
state.  Besides being used as a public water supply, it is a valuable
recreational  asset.  Activities such as camping, fishing, and swimming
attract many Iowa residents and out-of-state visitors;  and private
residences, cabins, and commercial establishments ring  the shoreline.
Abundant gamefish present include perch, smallmouth and largemouth bass,
and walleyes.  Some bluegills, crappies, and channel catfish can also be
caught.  The watershed is almost entirely agricultural.
    All of the Iowa Great Lakes have been classified as eutrophic but
in varying degrees.  Nuisance algal blooms are most severe in Lower  Gar
Lake and Lake East Okoboji, although all of the lakes  have summer algae
problems.  There has been an apparent decrease of macrophyte and muolTuscan
species diversity in recent years, as well as an increase in the abundance

* Description of the lake from Bachmann and Jones (1974).

-------
                                      2
         of blue-green algae.  However, sediment core samples indicate
         that the Iowa Great Lakes chain has been eutrophic for several
         thousand years.
             It has been estimated that the lake chain as a whole
         receives only 3% of the total  phosphorus load from urban
         sources with the remainder contributed by agricultural runoff
         and other non-point sources; feedlots contribute about 10%
         of the phosphorus load to Spirit Lake.
II.   CONCLUSIONS
     A.   Trophic Condition:
             Survey data indicate that Spirit Lake is eutrophic.   It
         ranked first in overall trophic quality when the 15 Iowa lakes
         and reservoirs sampled in 1974 were compared using a combination
         of six water quality parameters*.  However, based on their more
         extensive studies, Bachman and Jones (op. cit.)  consider West
         Okoboji Lake to be of better overall trophic quality than
         Spirit Lake.
             None of the other Iowa water bodies had less median  total
         phosphorus and median orthophosphorus, three had less median inor-
         ganic nitrogen and mean chlorophyll a_, and two had greater mean
         Secchi disc transparency.
             Survey limnologists observed some surface phytoplankton during
         the July sampling at all stations.
     B.   Rate-Limiting Nutrient:
             The algal assay results indicate that Spirit Lake was phos-
 * See Appendix A.

-------
                             3
phorus limited at the time the sample was  collected  (04/23/74).
The lake data indicate phosphorus limitation at stations  1  and
2 in April but nitrogen limitation at station 3.   Nitrogen  limi-
tation is indicated at all three stations  in September.

-------
III.   LAKE AND DRAINAGE BASIN CHARACTERISTICS1"
      A.   Lake Morphometry  :
          1.   Surface area:  23.00 kilometers2.
          2.   Mean depth:   5.5 meters.
          3.   Maximum depth:  7.3 meters.
          4.   Volume:  126.500 x 106  m3.
          5.   Mean hydraulic retention  time:   Unknown.
      C.   Precipitation*:
          1.   Year of sampling:   71.8 centimeters.
          2.   Mean annual:   70.5 centimeters.
  t Table of metric conversions—Appendix B.
  tt Harrison,  1975.
  * See Working Paper No.  175,  "...Survey Methods,  1973-1976",

-------
                                      5
IV.   LAKE WATER QUALITY SUMMARY
     Spirit Lake was  sampled three times  during  the  open-water season
 of 1974 by means of  a pontoon-equipped Huey helicopter.   Each time,
 samples for physical  and chemical  parameters were collected  from one
 or more depths at three stations on the  lake (see map,  page  v).   During
 each visit, a single depth-integrated (near bottom  to surface)  sample
 was composited from  the stations for phytoplankton  identification
 and enumeration; and during the first visit, a  single 18.9-liter depth-
 integrated sample was composited for algal  assays.   Also  each time,
 a depth-integrated sample was collected  from each of the  stations
 for chlorophyll  ^analysis.  The maximum depths sampled were 4.6 meters
 at station 1, 4.9 meters at station 2, and  4.6  meters at  station 3.
     The sampling results are presented in full  in Appendix C and are
 summarized in the following table (the July nutrient samples were
 not preserved properly and were not analyzed).

-------
PARAMETER

TEMP (C)

DISS OXY (MG/L>

CNDCTVY (MCROMO)

PH (STAND UNITS)

TOT ALK (MG/L)

TOT P (MG/L>

ORTHO P (MG/L)

N02»N03 (MG/L)

AMMONIA (MG/L)

KJEL N  (MG/L)

INORG N (MG/L)

TOTAL N (MG/L)

CHLBPYL A (UG/L)

SECCHI  (METERS)
A. SUMMARY OF PHYSICAL AND


1ST SAMPLING ( 4/23/74)

      3 SITES
CHEMICAL CHARACTERISTICS FOR SPIRIT LAKE
 STORET CODE 1913

           2ND SAMPLING ( 7/ 9/74)

                 3 SITES
                                                                                                          3RD SAMPLING  ( 9/23/74)

                                                                                                                3 SITES
RANGE
8.5 -
10.0 -
332. -
8.4
186.
0.030
0.002
0.080
0.030
0.900
0.120
0.990
2.3
2.7
-
- 0
- 0


- 1
- 0
• 1
-
8.7
10.6
337.
8.4
193.
.049
• 019
.110
.050
.100
• 160
.210
2.6
3.7
MEAN
8.6
10.3
335.
8.4
191.
0.037
0.007
0.097
0*041
0«967
0.138
1.063
2.5
3.1
MEDIAN RANGE MEAN MEDIAN
8.7 24.1 - 24.9 24.6 24.6
10.3 6.0 - 8.2 7.6 8.0
335. 544. - 555. 549. 548.

0
0
0
0
1
0
1

8.4 8.6 - 8.7 8.6 8.6
.034 «•••»» -««•«•»*>•«»«•*»•«>***•





2.5 13.8 - 15.4 14.6 14.7
3.0 1.5 - 1.5 1.5 1.5

0
0
0
0
1
0
1

RANGE
15.2 -
9.0 -
367. -
8.3
167.
.038
.006
.020
.020
.200
.040
.220
19.5
1.1
-
- 0
- 0
- 0
- 0
- 1
- 0
- 1
-
15.5
9.4
369.
8.4
182.
.058
.013
.030
.040
.400
.060
.420
22.4
1.4
MEAN
15.3
9.2
368.
8.4
174.
0.045
0.009
0.021
0.030
1.278
0.051
1 .299
20.8
1.2
MEDIAN
15.3
9.2
368.
8.4
173.
0.043
0.009
0.020
0.030
1.300
0.050
1.320
20.4
1.2

-------
B.   Biological  Characteristics:

    1.  Phytoplankton -
        Sampling
        Date

        04/23/74
        07/09/74
        09/23/74
    2.   Chlorophyll  a_ -

        Sampling
        Date

        04/23/74
        07/09/74
        09/23/74
Dominant
Genera

1.  Flagellates
2.  Dinobryon sp.
3.  Cryptomonas sp.
4.  Aphanothece sp.
5.  Dinoflagellates
    Other genera

            Total

1.  Aphanocapsa sp.
2.  Aphanizomenon sp.
3.  Schroederia sp.
4.  Anabaena sp.
5.  Cryptomonas sp.
    Other genera

            Total

1.  Aphanothece sp.
2.  Anabaena sp.
3.  Aphanizomenon sp.
4.  Coelosphaerium sp.
5.  Oscillatoria sp.
    Other genera

            Total
Station
Number

   1
   2
   3

   1
   2
   3

   1
   2
   3
Algal Units
per ml	

    912
    240
    144
     96
     48
     97
  1,537

  1,569
    262
    262
    232
    145
    174

  2,644

  1,182
    734
    326
    285
    245
    937

  3,709
Chlorophyll a_
(yg/1)

     2.6
     2.3
     2.5

    15.4
    14.7
    13.8
    22.
    20.
                                                             19.5

-------
                             8
Limiting Nutrient Study:
1.  Autoclaved, filtered, and nutrient spiked -
                     Ortho P          Inorganic N    Maximum yield
    Spike (mg/1)     Cone, (mg/1)     Cone,  (mg/1)    (mg/l-dry wt.)
    Control              0.005             0.109           0.1
    0.050 P             0.055             0.109           3.1
    0.050 P + 1.0 N     0.055             1.109          16.1
    1.0 N               0.005             1.109           0.1
2.  Discussion -
        The control yield of the assay alga,  Selenastrum capri-
    cornutum, indicates that the potential primary  productivity
    of Spirit Lake was low at the time the assay sample was
    taken (04/23/74).   The results also indicate phosphorus  limi-
    tation at that time.  Note the significant increase in yield
    when only orthophosphorus was added and  the lack of yield
    response when only nitrogen was added.
        The lake data indicate phosphorus limitation in April  at
    stations 1 and 2;  i.e., the mean inorganic nitrogen to ortho-
    phosphorus ratios  were 45 to 1 and 33 to  1, respectively.
    However, nitrogen limitation is- indicated at station 3 (the
    mean N/P ratio was 11/1).
        The September lake data indicate nitrogen limitation at
    all stations; i.e., the mean N/P ratios  were 6/1 or less,
    and nitrogen limitation would be expected.

-------
V.   LITERATURE REVIEWED

    Anonymous, 1974.   Management plan  for water  quality—Iowa Great
        Lakes.  E. A.  Hickok and Assoc.,  Wayzata,  Minnesota.

    Bachmann, Roger W., and John R.  Jones, 1974.   Water  quality  in
        the Iowa Great Lakes.  MS,  Dept.  of Zoo. & Ent.,  IA St.  U.,
        Ames.

    Harrison, Harry M., 1975.  Personal  communication  (lake morphometry).
        IA Cons. Comm., Des Moines.

-------
VI.  APPENDICES
                                  APPENDIX A
                                 LAKE RANKINGS

-------
LAKE DATA TO BE USED IN RANKlNGb

LAKE
CODE  LAKE NAME

1901  LAKE ACOUA6I

1902  8IG CREEK RESERVOIR

1903  SLACK HAWK LAKE

1904  CLEAR LAKE

1905  LAKE DARLING

1906  LOST ISLAND LAKE

1907  LAKE MACBPIOE

1908  PRAIRIE ROSE LAKE

1909  RATHBUN RESERVOIR

1910  RED ROCK LAKE

1911  ROCK CREEK LAKE

1912  SILVER LAKE

1913  SPIRIT LAKE

1914  VIKING LAKE

1915  WEST LAKE OKOBOJI
MEDIAN
TOTAu H
0.06?
0.046
0.185
0.059
0.077
0.146
0.061
0.056
0.071
0.180
0.065
0.193
0.041
0.075
0.046
MEDIAN
1NO«G N
0.3J5
6.465
0.130
0.070
1.475
0.065
2.035
0.210
1.170
1.880
1.400
0.565
0.090
0.130
0.060
500-
MEAN SEC
469.333
436.500
488.167
465.125
482.500
421.167
458.444
463.667
475.889
473.400
480.500
482.667
422.667
459.000
380.444
MEAN
CuLOrtA
8.600
16.867
49.740
17.400
13.817
36.100
17.067
17.350
12.039
14.730
18.367
95.300
12.622
26.033
7.722
15-
HIN DO
8.200
14.800
15.000
8.600
9.200
8.400
15.000
8.600
14.000
14.000
8.400
10.000
9.000
14.200
15.000
MEDIAN
DISS OKTrtO P
0.009
0.011
0.020
0.010
0.012
0.021
0.010
0.010
0.008
0.104
0.007
0.034
0.007
0.017
0.017

-------
PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES)
LAKE
CODE  LAKE NAME
1901  LAKE ACOUABI
190?  BIG CREEK RESERVOIR
1903  BLACK HAWK LAKE
1904  CLEAR LAKE
1905  LAKE DARLING
1906  LOST ISLAND LAKE
1907  LAKE MACBRIDE
1908  PRAIRIE ROSE LAKE
1909  RATHBUN RESERVOIR
1910  RED ROCK LAKE
1911  ROCK CREEK LAKE
1912  SILVER LAKE
1913  SPIRIT LAKE
191*  VIKING LAKE
1915  WEST LAKE OKOBOJI
MEDIAN
TOTAL P
57 (
69 (
7 (
71 (
29 (
21 (
64 (
79 (
43 (
1* (
50 (
0 (
100 (
36 (
89 (
8)
12)
1)
10)
4)
3)
9)
11)
6)
2)
7)
0)
14)
5)
12)
MEDIAN
INO*G N
50 (
0 (
foB (
86 (
21 (
93 (
7 (
57 (
36 (
14 (
29 <
43 <
79 (
68 (
100 (
7)
0)
9)
12)
3)
13)
1)
8)
5)
2>
4)
6)
11)
9)
14)
500-
MEAN SEC
43 (
79 (
0 (
50 (
14 (
93 (
71 (
57 (
29 (
36 (
21 (
7 (
86 (
64 (
100 (
6)
11)
0)
7)
2)
13)
10)
8)
4)
5)
3)
1)
12)
9)
14)
MEAN
CHLORA
93 (
57 (
7 (
36 (
71 (
1* (
50 <
43 <
86 (
64 (
29 (
0 (
79 (
21 (
100 (
13)
8)
1)
5)
10)
2)
7)
6)
12>
9)
4)
0)
11)
3)
14)
15-
MIN DO
100
21
7
75
57
89
7
75
39
39
89
50
64
29
7
I 14)
( 3)
( 0)
( 10)
( 8)
( 12)
( 0)
( 10)
( 5)
( 5)
( 12)
< 7)
( 9)
( 4)
( 0)
MEDIAN
DISS ORTHO P
79 (
50 (
21 (
64 <
43 (
14 (
64 (
64 {
86 (
0 (
96 <
7 (
96 (
32 (
32 (
11)
7)
3)
8)
6)
2)
8)
8)
12)
0)
13)
1)
13)
4)
4)
INDEX
NO
422
296
110
382
235
324
263
375
319
167
314
107
504
250
428

-------
LAKES RANKED 8V INDEX NOS.




RANK  LAKE CODE  LAKE NAME               INDEX NO






   1  1913       SPIRIT LAKE                504




   2  1915       WEST LAKE OK080JI          428



   3  1901       LAKE ACOUABI               422




   4  1904       CLEAR LAKE                 382




   5  1908       PRAIRIE ROSE LAKE          375




   6  1906       LOST ISLAND LAKE           324



   7  1909       RATHBUN RESERVOIR          319




   8  1911       ROCK CREEK LAKE            314



   9  1902       BIG CREEK RESERVOIR        296



  19  1907       LAKE MACBRIDE              263




  11  1914       VIKING LAKE                250



  12  1905       LAKE DARLING               235



  13  1910       RED ROCK LAKE              167




  14  1903       BLACK HAWK LAKE            110



  15  1912       SILVER LAKE                107

-------
    APPENDIX B
CONVERSION FACTORS

-------
                CONVERSION FACTORS

Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
Cubic meters x 8.107 x 10   = acre/feet
Square kilometers x 0.3861 = square miles
Cubic meters/sec x 35.315 = cubic feet/sec
Centimeters x 0.3937 = inches
Kilograms x 2.205 = pounds
Kilograms/square kilometer x 5.711 = Ibs/square mile

-------
        APPENDIX C
PHYSICAL and CHEMICAL DATA

-------
STOREf RETRIEVAL DATE 7b/l'J/21
                                                                  191301
                                                                 43 27 21.0 095 06 08.0
                                                                 SPIRIT LAKE
                                                                 19      IOWA
  DATE   TIME DEPTH
  FROM    OF
   TO    DAY  FEET

74/04/23 10 00 0000
         10 00 0005
         10 00 0015
74/07/09 14 ?5 0000
         14 25 0005
         14 25 0015
74/^9/23 14 55 0000
         14 55 0005
         14 55 0014
                                          11EPALES
                                          3
 2111202
0019 FEET
                                                                                                DEPTH
00010
WATER
TtMP
CENT
8.7
8.7
8.7
24.7
24.6
24. 1
15.3
15.3
15.3
00300
00

MG/L

10.4
10.4
6.0
a.o
7.6
9.0
9.4
9.2
00077
TRANSP
SECCHI
INCHES
108


60


54


00094
CNDUCTVY
FIELD
MICROMHO
336
334
337
555
552
553
368
368
368
00400
PH

SU
8.40
8.40
8.40
8.60
8.60
8.60
8.32
8.34
8.39
00410
T ALK
CAC03
MG/L
186
190
192



173
176
173
00610
NH3-N
TOTAL
MG/L
0.040
0.040
0.040



0.030
0.030
0.030
00625
TOT KJEL
N
MG/L
0.900
0.900
1.000



1.300
1.-300
1.400
00630
N02&N03
N-TOTAL
MG/L
0.100
0.110
0.090



0.020K
0.020
0.020
00671
PHOS-DIS
ORTHO
MG/L P
0.002
0.006
0.004



0.006
0.008
0.012
  DATE   TIME DEPTH
  FROM    OF
   TO    DAY  FEET

74/04/23 10 00 0000
         10 00 0005
         10 00 0015
74/07/09 14 ?5 0000
74/09/23 14 55 0000
         14 55 0005
         14 55 0009
         14 55 0014
J665
'b-TOf

i/L P
O.C31
C.043
0.049

•j.03d
0.041
32217
CHLRPHYL
A
'UG/L
2.6


15.4
2?. 4

00031
INCOT LT
REMNING
PERCENT






                      1.0
u.043
          K VALUE KNOWN TO BE
          LESS THAN INDICATED

-------
STORET RETRIEVAL DATE 75/10/21
                                                                  191302
                                                                 43 29 03.0 095 06 18.0
                                                                 SPIRIT LAKE
                                                                 19      IOWA

DATE
FROM
TO
74/04/23


74/07/09


74/09/23



TIME DEPTH
OF
(JAY FEET
10 20 0000
10 20 0005
10 20 0016
14 49 0000
14 49 0005
14 49 U016
14 00 0000
14 00 0005
14 00 0015
00010
•HATER
TEMP
CENT
8.7
8.7
8.7
24.6
?4.b
24.3
15.2
15.2
15.2
                                00300     00077     00094
                                 DO      TRANSP   CNDUCTVY
                                         SECChI   HELD
                                MG/L     INCHES   MICROMHO
                                  10.0
                                  10.0
                                   6.2
                                   7.2
                                   7.2
                                   9.2
                                   9.2
                                   9.2
                                             144
                60
                42
335
335
3J6
550
548
547
367
367
368
11EPALES
3
00^00
PH

ill
8.40
8.40
8.40
8.60
8.60
8.60
8.39
8.40
8.40

00410
T ALK
CAC03
MG/L
190
192
192



182
167
172
211
0020
00610
NH3-N
TOTAL
Mli/L
0.050
0.040
0.040



0.030
0.030
0.030
1202


FEET DEPTH
00625
TOT KJEL
N
MG/L
0.900
0.900
1.000



1.300
1.200
1.200
(JO 630
N02&N03
N-TOTAL
MG/L
0.100
0.090
0.080



0.020K
0.030
0.020K
00671
PMOS-iDIS
URTriO
MG/L P
0.004
0.004
0.004



0.013
0.009
0.012
                      00665
  DATE   TIME DEPTH PHOS-TOT
  FROM    OF
   TO    DAY  FtET   MG/L P

74/04/23 10 20 0000    0.030
         10 20 0005    0.03d
         1U 20 0016    0.030
74/07/09 14 49 0000
74/09/23 14 00 0000    0.05s
         14 00 0005    u.U<*5
         14 00 0009
         14 00 0015    0.0«8
  32217     00031
CHLRPHYL  INCDT LT
   A      REMNING
  UG/L    PERCENT

     2.3
    14.7
    20.4

               1.0
           K VALUE KNOWN TO BE
           LESS THAN INDICATED

-------
STORET RETRIEVAL DATE 75/10/21
                                                                  191303
                                                                 43 29 20.0 095 03 58.0
                                                                 SPIRIT LAKE
                                                                 19      IOWA

DATE
FROM
TO
74/04/23


74/07/09


74/09/23



TIME OEPTH
OF
DAY FEET
10 35 0000
10 35 0005
10 35 0014
15 13 0000
15 13 U005
15 13 0014
14 30 0000
14 30 0005
14 30 OOlb
00010
WATER
TEMP
CENT
8.5
8.6
8.5
24.9
24.8
24.6
15.5
15.4
15.4
                                00300     OOC77     00094
                                 DO      TRANSP   CNDUCTVY
                                         SECCHI   FIELD
                                MG/L     INCHES   M1CHOMHO
                                  1C.2
                                  10.6
                                   8.0
                                   8.0
                                   8.0
                                   9.4
                                   9.2
                                   9.4
                                             120
                       60
                       48
334
334
332
544
544
544
368
368
369
11EPALES
3
00400
PH

SU
8.40
8.40
8.40
8.70
8.70
8.70
8.40
8.37
8.39

00410
T ALK
CAC03
MG/L
193
193
193



173
173
173
211
0018
00610
NH3-N
TOTAL
MG/L
0.050
0.040
0.030



0.030
0.040
0.020
1202


FEET OEPTH
00625
TOT KJEL
N
MG/L
1.100
1.000
1.000



1.300
1.300
1.200
00630
N02&N03
N-TOTAL
MG/L
0.110
0.100
0.090



0.020K
0.020K
0.020K
00671
PHOS-DIS
ORTHO
MG/L P
0.019
0.013
0.006



0.007
0.009
0.008
  DATE   TIME OEPTH
  FROM    OF
   fU    DAY  FEET

74/04/23 10 35 0000
         10 35 0005
         10 35 0014
74/0 7/09 15 13 0000
74/09/23 14 30 0000
         14 30 0005
         14 30 0009
         14 30 0015
D066S
JS-TUT

3/L P
0.033
U.042
0.034

0.040
0.042
32217
CHLRPHYL
A
UG/L
2.5


13.8
19.5

00031
INCDT LT
REMNING
PERCENT


'



                      1.0
).04b
          K VALUE KNOWN TO BE
          LESS THAN INDICATED

-------