U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
SILVER LAKE
MONOOTIY
CALIFORNIA
EPA REGION IX
WORKING PAPER No, 759
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
-------
RlPORT
ON
SILVER LAKE
MONO COUNTY
CALIFORNIA
EPA REGION IX
WORKING PAPER No, 759
WITH THE COOPERATION OF THE
CALIFORNIA STATE WATER RESOURCES CONTROL BOARD
AND THE
CALIFORNIA NATIONAL GUARD
JUNE, 1978
-------
CONTENTS
Page
Foreword ii
List of California Study Lakes iv
Lake and Drainage Area Map v
Sections
I. Introduction 1
II. Conclusions 1
III. Lake and Drainage Basin Characteristics 2
IV. Water Quality Summary 3
V. Literature Reviewed 7
VI. Appendices 8
-------
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)], water
quality criteria/standards review [§303(c)], 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.
-------
m
Beyond the single lake analysis, broader based correlations
between nutrient concentration (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.
ACKNOWLEDGEMENT
The staff of the National Eutrophication Survey (Office of
Research & Development, U.S. Environmental Protection Agency)
expresses sincere appreciation to the California State Water
Resources Control Board and the nine Regional Water Quality
Control Boards for professional involvement, to the California
National Guard for conducting the tributary sampling phase of
the Survey, and to those California wastewater treatment plant
operators who voluntarily provided effluent samples and flow
data.
The staff of the Division of Planning and Research of the
State Water Resources Control Board provided invaluable lake
documentation and counsel during the Survey, coordinated the
reviews of the preliminary reports, and provided critiques
most useful in the preparation of this Working Paper series.
Major General Glen C. Ames, the Adjutant .General of Cali-
fornia, and Project Officer Second Lieutenant Terry L. Barrie,
who directed the volunteer efforts of the California National
Guardsmen, are also gratefully acknowledged for their assistance
to the Survey.
-------
IV
NATIONAL EUTROPHICATION SURVEY
STUDY RESERVOIRS
State of California
Name
Amador
Boca
Britton
Casitas
Crowley
Don Pedro
El si nore
Fallen Leaf
Hennessey
Henshaw
Iron Gate
Lopez
Mary
Mendocino
Nicasio
Lower Otay
Pillsbury
Santa Margarita
Shasta
Shaver
Silver
Tahoe
julloch
Lower Twin
Upper Twin
County
Amador
Nevada
Shasta
Ventura
Mono
Tuolumne
Riverside
El Dorado
Napa
San Diego
Siskiyou
San Luis Obispo
Mono
Mendocino
Marin
San Diego
Lake
San Luis Obispo
Shasta
Fresno
Mono
El Dorado, Placer, CA;
Carson City, Douglas,
Washoe, NV
Calaveras, Tuolumne
Mono
Mono
-------
SILVER LAKE
X Lake Sampling Site
i 2 3 Km.
i
1/2
11/2 Mi.
Scale
37°50'
Map Location
-------
SILVER LAKE
STORE! NO. 0623
I. INTRODUCTION
Silver Lake was included in the National Eutrophication Survey as
a water body of interest to the California State Water Resources Control
Board. Tributaries and nutrient sources were not sampled, and this re-
port relates only to the lake sampling data.
II. CONCLUSIONS
A. Trophic Condition*:
Survey data indicate that Silver Lake is oligotrophic. It
ranked third in overall trophic quality among the 24 Cali-
fornia lakes and reservoirs sampled in 1975 when compared using
a combination of six water quality parameters**. Two of the water
bodies had less and one had the same median total phosphorus,
one had less and two had the same median dissolved orthophos-
phorus, eight had less median inorganic nitrogen, three had
less mean chlorophyll a_, and five had greater mean Secchi disc
transparency. No depression of dissolved oxygen with depth
occurred at any of the three sampling times.
B. Rate-Limiting Nutrient:
The algal assay results are not considered representative
of conditions in the lake at the times samples were collected.
The lake data indicate nitrogen limitation in early June but
phosphorus limitation at the other two sampling times.
* Trophic assessment is based on levels of nutrients, dissolved oxygen, and
chlorophyll a; photoplankton kinds and numbers; and transparency (Allurn
et al,, 19777.
** See Appendix A.
-------
III. LAKE AND DRAINAGE BASIN CHARACTERISTICS1"
A. Morphometrytt:
1. Surface area: 0.45 kilometers2.
2. Mean depth: 10.5 meters.
3. Maximum depth: Unknown.
4. Volume: 4.737 x 106 m3.
B. Precipitation*:
1. Year of sampling: 8.1 centimeters.
2. Mean annual: 14.5 centimeters.
t Table of metric equivalents—Appendix B.
tt Dendy, 1974.
* See Working Paper No. 175, "... Survey Methods, 1973-1976",
-------
IV. WATER QUALITY SUMMARY
Silver 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 a
number of depths at one station on the lake (see map, page v). Dur-
ing each visit, a single depth-integrated (4.6 m to surface) sample
was collected for phytoplankton identification and enumeration, and
a similar sample was taken for chlorophyll a_ analysis. During the
first and last visits, a single 18.9-liter depth-integrated sample
was collected for algal assays. The maximum depth sampled was 14.6
meters.
The sampling results are presented in full in Appendix C and are
summarized in the following table.
-------
PARAMETER
TEMP (C)
OISS 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)
CHLRPYL A (UG/L)
SECCHI (METERS)
A. SUMMARY OF PHYSICAL AND
1ST SAMPLING < 6/10/75)
1 SITES
CHEMICAL CHARACTERISTICS FOR SILVER LAKE
STORET CODE 0623
2ND SAMPLING ( 6/30/75)
1 SITES
RANGE
4.9 -
8.0 -
32. -
7.5 -
18. -
0.012 - 0.013
0.009 - 0.015
0.030 - 0.040
0.030 - 0.040
0.200 - 0.200
0.060 - 0.080
0.230 - 0.240
1.5 -
3.2 -
3RD SAMPLING (ll/ 5/75)
1 SITES
7.4
9.6
33.
7.7
23.
013
015
040
040
200
080
240
1.5
3.2
MEAN
5.9
9.1
32.
7.6
20.
0.012
0.013
0.034
0.032
0.200
0.066
0.234
1.5
3.2
MEDIAN
5.8
9.4
32.
7.6
20.
0.012
0.014
0.030
0.030
0.200
0.060
0.230
1.5
3.2
RANGE
5.6
8.4
25.
7.5
23.
0.010
0.002
0.020
0.020
0.200
0.040
0.220
2.2
4.1
8.0
8.6
41.
7.7
26.
- 0.013
- 0.004
- 0.050
- 0.040
- 0.200
- 0.070
- 0.250
2.2
4.1
MEAN
7.3
8.5
31.
7.6
25.
0.011
0.003
0.028
0.026
0.200
0.054
0.228
2.2
4.1
MEDIAN
7.5
8.6
30.
7.5
26.
0.010
0.003
0.020
0.020
0.200
0.050
0.220
2.2
4.1
RANGE
6.1
8.6
61.
7.5
22.
0.010
0.002
0.020
0.020
0.200
0.040
0.220
1.7
6.2
9.2
63.
7.5
23.
- 0.014
- 0.002
- 0.020
- 0.020
- 0.200
- 0.040
- 0.220
1.7
MEAN
6.1
8.8
62.
7.5
23.
0.011
0.002
0.020
0.020
0.200
0.040
0.220
1.7
MEDIAN
6.1
8.8
62.
7.5
23.
0.010
0.002
0.020
0.020
0.200
0.040
0.220
1.7
»«»»«« .»««»«»««»»««««*»««««««
-------
B. Biological characteristics:
1. Phytoplankton -
Sampling
Date
Dominant
Genera
Algal Units
per ml
06/10/75
1. Chroomonas (?) sp.
2. Dinobryon sp.
3. Asterionella sp.
4. Cryptomonas sp.
5. Synedra sp.
Total
343
115
38
38
38
572
06/30/75
1. Chroomonas (?) sp.
2. Dinobryon sp.
3. Synedra s£.
4. Asterionella sp.
Total
228
114
114
76
532
11/05/75
1. Chroomonas (?) sp.
2. Cryptomonas sp.
3. Dinobryon sp.
57
45
11
Total
113
-------
2. Chlorophyll a^ -
Sampling Station Chlorophyll a^
Date Number (yg/1)
06/10/75 1 1.5
06/30/75 1 2.2
11/05/75 1 1.7
C. Limiting Nutrient Study:
The algal assay results are not considered representative
of conditions in the lake due to significant changes in nu-
trients in the samples during shipment from the field to the
laboratory. However, the lake data indicate nitrogen limi-
tation in early June and phosphorus limitation in late June
and in November. The mean inorganic nitrogen/orthophosphorus
ratios were 5/1 in early June and 18/1 or greater at the other
sampling times.
-------
V. LITERATURE REVIEWED
Allum, M.O., R.E. Glessner, and J.H. Gakstatter, 1977. An evalua-
tion of the National Eutrophication Survey data. Working Paper
No. 900, Corvallis Env. Res. Lab. Corvallis, OR.
Dendy, William B., 1974. Personal communication, (waterbody in-
formation and morphometry). CA Water Res. Contr. Bd., Sacra-
mento.
-------
VI. APPENDICES
APPENDIX A
LAKE RANKINGS
-------
LAKE DATA TO rtE USED IN BANKINGS
LAKE
COOE LAKE NAME
ObOl AMADOU RESERVOIR
0602 BOCA LAKE
0603 LAKE flPlTTON
060<> CASITAS RESERVOIR
060S CROWLEY-LAKE
0606 DON PEORO RESERVOIR
0607 LAKE ELSIMORE
060H FALLEN LEAF RESERVOIR
0609 LAKE HENNESSEY
0610 LAKE HENSHAri
0611 IRON GATE RESERVOIR
0614 LOPEZ LAKE
0615 LAKE MARY
0616 LAKE MENOOCINO
0617 N1CASIO RESERVOIR
0618 LOWER OTAY RESERVOIR
0619 LAKE PILLSBURY
0620 SANTA MARGARITA LAKE
0621 SHASTA LAKE
0622 SHAVER
0623 SILVEK LAKE
0624 TULLOCK RESERVOIR
0625 UPPER TWIN LAKES
0626 LOWER TWIN LAKES
MEDIAN
TOTAL P
0.040
0.012
0.067
0.029
0.04*
0.013
0.469
0.007
0.027
0.138
0.184
0.371
0.010
0.020
0.055
0.058
0.022
0.037
0.021
0.014
0.012
0.025
0.015
0.014
MEDIAN
INORG N
0.390
0.040
0.115
0.050
0.045
0.060
0.120
0.040
0.060
0.070
0.690
0.090
0.040
0.050
0.345
0.180
0.060
0.070
0.060
0.060
0.055
0.060
0.040
0.04Q
500-^
MEAN SEC
408.667
372.833
446.500
400.250
374.750
381.733
489.214
24.357
416.000
461.000
440.333
372.000
296.000
436.500
482.778
447.250
466.667
400.000
381.542
346.400
356.000
433.000
300.200
24B.OOO
MEAN
CHLOHA
22.383
1.700
4.811
3.192
5.800
3.564
70.572
0.786
4.525
26.783
6.217
8. 658
2.550
3.100
6.633
15.933
6.389
9.122
4.087
1.700
1.800
13.878
3.340
2.900
15-
MIN 00
14.600
6.800
11.200
14.000
12.200
11.400
8.000
8.800
15.000
9.800
13.800
15.000
10.600
9.400
9.800
15.000
B.200
14.800
9.000
7.400
7.000
7.400
7.400
11.400
MEDIAN
DISS OHTHO P
0.020
0.003
0.047
0.014
0.034
0.004
0.092
0.005
0.012
0.073
0.124
0.343
0.002
0.008
0.013
0.013
0.008
0.014
0.015
0.004
0.003
0.009
0.004
0.003
-------
PERCENT OF L4KES wlTri HIGHER VALUES (NUMBER OF LAKES <*ITti HIGHER VALUES)
LAKE
COOE LAKE NAME
0601 AMAOOR RESERVOIR
0602 BOCA LAKE
0603 LAKE BPITTON
060* CASITAS RESERVOIR
0605 CROWLEY LAKE
0606 DON PEO»0 RESERVOIR
0607 LAKE ELSINORE
0608 FALLEN LEAF RESERVOIR
0609 LAKE HENNESSEY
0610 LAKE HENSHAW
0611 IRON GATE RESERVOIR
061* LOPEZ LAKE
0615 LAKE MARY
0616 LAKE MENOOCINO
0617 NICASIO RESERVOIR
0618 LOWER OTAY RESERVOIR
06i<» LAKE PILLSBURY
0620 SANTA MARGARITA LAKE
0621 SHASTA LAKE
0622 SHAVER
062J SILVER LAKE
062* TULLOCK RESERVOIR
0625 UPPtR TWIN LAKES
0626 LOWER TWIN LAKES
MEDIAN
TOTAL P
35
89
17
43
30
83
0
100
48
13
9
4
96
65
26
22
57
39
61
78
89
52
70
74
( 8)
( 20)
( 4)
( 10)
( 7)
( 19)
( 0)
( 23)
( ID
( 3)
( 2)
( 1)
( 22)
( IS)
( 6)
( 5)
( 13)
( 9)
( 14)
( 18)
(20)
( 12)
( 16)
( 17)
MEDIAN
INORG N
4
98
22
74
78
54
17
b7
54
33
0
26
87
70
9
13
41
33
54
41
65
54
98
87
( 1)
( 22)
t 5)
( 17)
( 18)
( 11)
( 4)
( 19)
( ID
( 7)
( 0)
( 6)
( 19)
( 16)
( 2)
( 3)
( 9)
( 7)
( 11)
( 9)
( 15)
( 11)
( 22)
( 19)
500-
MEAN SEC
43
70
17
48
65
57
0
100
39
13
26
74
91
30
4
22
9
52
61
83
78
35
87
96
( 10)
( 16)
( 4)
( 11)
( 15)
( 13)
( 0)
< 23)
( 9)
( 3)
( 6)
< 17)
( 21)
( 7)
( 1)
< 5)
( 2)
( 12)
( 14)
(. 19)
( 18)
( 8)
( 20)
( 22)
MEAN
CHLORA
9 i
91
48
7C i
43
61 i
0 i
100 i
52 I
4 1
39.1
26 1
83 1
74 1
30 1
13 1
35 1
22 (
57 (
96 1
87 (
17 (
65 <
78 <
( 2)
t 21)
I 11)
( 16)
( 10)
I U)
[ 0)
1 23)
1 12)
1 1)
( 9)
I 6)
! 19)
1 17)
1 7)
I 3)
I 8)
I 5)
I 13)
: 22)
20)
4)
15)
18)
1S-
MIN 00
17
100
43
22
30
37
78
70
4 i
54
26
4 I
48 I
61 I
54 i
4 1
. 74 1
13 1
65 1
87 (
96 1
87 (
87 (
37 (
( 4)
< 23)
( 10)
( 5)
( 7)
I 8)
( 18)
( 16)
( 0)
( 12)
( 6)
1 0)
1 .11)
I 14)
t 12)
I 0)
I 17)
t 3)
I 15)
! 19)
: 22)
! 19)
: 19)
8)
MEDIAN
OISS ORTHO P
26
91
17
37
22
78
9
70
52
13
4
0
100
63
46
46
63
37
30
78
91
57
78
91
( 6)
( 20)
( 4)
( 8)
( 5)
( 17)
( 2)
( 16)
( 12)
( 3)
( 1)
( 0)
( 23)
( 14)
( 10)
( 10)
( 14)
( 8)
( 7)
( 17)
( 20)
( 13)
( 17)
( 20)
INDEX
NU
134
539
164
294
268
370
104
527
249
130
104
134
505
363
169
120
279
196
328
463
506
302
485
463
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LAKES RANKED BY INDEX NOS.
RANK LAKE CODE LAKE NAME INDEX NO
1 060? BOCA LAKE 539
2 0608 FALLEN LEAf RESERVOIR 527
3 0623 SILVER LAKE 506
4 0615 LAKE MARY 505
5 0625 UPPER THIN LAKES 485
6 0626 LOWER TWIN LAKES 463
7 0622 SHAVER 463
8 0606 DON PEDRO RESERVOIR 370
9 0616 LAKE MENDOCINO 363
10 0621 SHASTA LAKE 328
11 0624 TULLOCK RESERVOIR 302
12 0604 CASITAS RESERVOIR 294
13 0619 LAKE PILLSBURY 279
14 0605 CROtfLEY LAKE 268
15 0609 LAKE HENNESSEY 249
16 0620 SANTA MARGARITA LAKE 196
17 0617 NICASIO RESERVOIR 169
18 0603 LAKE 6RITTON 164
19 0614 LOPEZ LAKE 134
20 0601 AMADOR RESERVOIR 134
21 0610 LAKE HENSHArf 130
22 0618 LOWER OTAY RESERVOIR 120
23 0607 LAKE ELSINOrtE 104
24 0611 IRON GATE RESERVOIR 104
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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 ~4 = 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
-------
STORE! RETRIEVAL DATE 76/09/24
062301
37 46 44.0 119 07 33.0 3
SILVER LAKE
06051 CALIFORNIA
11EPALES 751126 2111302
0045 FEET DEPTH CLASS 00
DATE
FROM
TO
75/06/10
75/06/30
75/11/05
DATE
FROM
TO
75/06/10
75/06/30
75/11/05
TIME DEPTH
OF
DAY FEET
09 00 0000
09 00 0005
09 00 0020
09 00 0031
09 00 0041
11 00 0000
11 00 0005
11 00 0015
11 00 0025
11 00 0045
14 15 0000
14 15 0005
14 15 0024
14 15 0048
TIME DEPTH
OF
DAY FEET
09 00 0000
09 00 0005
09 00 0020
09 00 0031
09 00 0041
11 00 0000
11 00 0005
11 00 0015
11 00 0025
11 00 0045
14 15 0000
14 15 0005
14 15 OC24
14 15 0048
00010
WATER
TEMP
CENT
7.*
5.9
5.8
5.5
4.9
8.0
7.9
7.5
7.3
5.6
6.2
6.1
6.1
6.1
00665
PHOS-TOT
MG/L P
0.013
0.012
0.012
0.012
0.012
0.010
0.010
0.010
0.013
0.012
0.014
0.010
0.011
0.010
00300
DO
MG/L
8.0
9.4
9.6
9.6
8.8
8.6
8.6
8.6
8.4
8.4
8.6
8.8
9.2
8.8
32217
CHLRPHYL
A
UG/L
1.5
2.2
1.7
00077 00094
TRANSP CNDUCTVY
SECCHI FIELD
INCHES MICROMHO
126 32
33
32
32
33
162 25
29
30
31
41
63
62
61
61
00031
INCDT LT
REMNING
PERCENT
00400
PH
SU
7.70
7.60
7.50
7.60
7.70
7.50
7.50
7.70
7.60
7.50
7.50
7.50
7.50
7.50
00410
T ALK
CAC03
MG/L
20
18
20
19
23
26
26
26
26
23
23
23
22
23
00610
00625
NH3-N TOT KJEL
TOTAL
MG/L
0.030
0.030
0.030
0.040
0.030
0.020
0.020
0.020
0.040
0.030
0.020K
0.020K
0.020K
0.020K
N
MG/L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.200K
.200K
.200K
.200K
.200K
.200K
.200K
.200K
.200
.200
.200K
.200K
.200K
.200K
00630
N02S.N03
N-TOTAL
MG/L
0.030
0.030
0.030
0.040
0.040
0.050
0.020K
0.020K
0.030
0.020
0.020K
0.020K
0.020K
0.020K
00671
PHOS-OIS
ORTHO
MG/L P
0.015
0.014
0.014
0.009
0.014
0.004
0.003
0.003
0.002
0.002K
0.002
0.002
0.002K
0.002
K V/SLUE KNO'vN TO dE
•LESS THAN INDICATED
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