U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
LAHONTAN RESERVOIR
CHURCHILL AND LYON COUNTIES
NEVADA
EPA REGION IX
WORKING PAPER No, 807
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
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REPORT
ON
LAHONTAN RESERMIR
CHURCHILL AND LYDN COUNTIES
NEVADA
EPA REGION IX
WORKING PAPER No, 807
WITH THE COOPERATION OF THE
NEVADA ENVIRONMENTAL PROTECTION SERVICE
AND THE
NEVADA NATIONAL GUARD
SEPTEMBER, 1977
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REPORT ON LAHONTAN RESERVOIR
CHURCHILL AND LYON COUNTIES, NEVADA
EPA REGION IX
by
National Eutrophication Survey
Water and Land Quality Branch
Monitoring Operations Division
Environmental Monitoring & Support Laboratory
Las Vegas, Nevada
and
Special Studies Branch
Corvallis Environmental Research Laboratory
Corvail is, Oregon
Working Paper No. 807
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
September 1977
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1
CONTENTS
Page
Foreword ii
List of Nevada Study Lakes iv
Lake and Drainage Area Map v
Sections
I. Conclusions 1
II. Lake and Drainage Basin Characteristics 4
III. Lake Water Quality Summary 6
IV. Nutrient Loadings 12
V. Literature Reviewed 17
VI. Appendices 18
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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 freshwater lakes and
reservoirs.
OBJECTIVES
The Survey was designed to develop, in conjunction with state
environmental agencies, information on nutrient sources, concen-
trations, 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 nonpoint source pollution abatement in lake water-
sheds.
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
watershed 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)j, 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.
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111
Beyond the single lake analysis, broader based correlations
between nutrient concentrations (and loading) and trophic
condition 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 the U.S. Environmental Protection Agency and to augment
plans implementation by the States.
ACKNOWLEDGMENTS
The staff of the National Eutrophication Survey (Office
of Research and Development, U.S. Environmental Protection
Agency) expresses sincere appreciation to the Nevada State
Environmental Protection Service for professional involvement,
to the Nevada National Guard for conducting the tributary
sampling phase of the Survey, and to those Nevada wastewater
treatment plant operators who provided effluent samples and
flow data.
The staff of the Department of Conservation and Natural
Resources, Division of Environmental Protection, State Environmental
Protection Service 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 Floyd L. Edsall, the Adjutant General of
Nevada, and Project Officer Major Harold E. Roberts, v/ho directed
the volunteer efforts of the Nevada National Guardsmen, are
also gratefully acknowledged for their assistance to the Survey.
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IV
NATIONAL EUTROPHICATION SURVEY
STUDY LAKES
STATE OF NEVADA
LAKE NAME
Lake Mead
Lahontan Reservoir
Rye Patch Reservoir
Lake Tahoe
Topaz Reservoir
Upper Pahranagat Lake
Washoe Lake
Wildhorse Reservoir
Wilson Reservoir
Walker Lake
COUNTY
Clark (Mohave in Arizona)
Lyon, Churchill
Pershing
Washoe, Carson City,
Douglas (Placer,
El Dorado in CA)
Douglas (Mono in CA)
Lincoln
Washoe
Elko
Elko
Mineral
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LAHONTAN RESERVOIR
Tributary Sampling Site
Lake Sampling Site
20 30
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REPORT ON LAHONTAN RESERVOIR, NEVADA
STORE! NO. 3202
I. CONCLUSIONS
A. Trophic Condition:*
Survey data indicate that Lahontan Reservoir is eutrophic,
i.e., nutrient rich and highly productive. Whether such nutrient
enrichment is to be considered beneficial or deleterious is
determined by its actual or potential impact upon designated
beneficial water uses of the lake.
Chlorophyll a_ values in the reservoir ranged from 1.3 yg/1
to 14.7 yg/1 with a mean of 4.6 yg/1. The potential for primary
productivity as measured by algal assay control yields was high.
Of the 10 Nevada lakes sampled in 1975, 2 had higher median
total phosphorus levels (0.198 mg/1), none had higher median
inorganic nitrogen values (0.350 mg/1), and 2 had higher median
orthophosphorus levels (0.148 mg/1) than Lahontan Reservoir.
Survey limnologists did not report any problem algal blooms
or macrophytes during their visits to the lake. However, it
was noted that the lake was highly turbid on all sampling occasions,
and low Secchi disc visibility (range 0.3 - 1.6 m) suggests that
primary productivity in the lake may be light limited.
*See Appendix E.
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B. Rate-Limiting Nutrient:
The algal assay results indicate that nitrogen was the primary
limiting nutrient in Lahontan Reservoir during the sampling year.
The mean inorganic nitrogen to orthophosphorus (N/P) ratios in the
sampled waters of 2/1 or less on the three sampling dates further
suggest primary limitation by nitrogen,
C. Nutrient Controllability:
1. Point Sources -
There were no known point sources directly impacting
Lahontan Reservoir during the sampling year. However, there
are a number of municipal sources that did not participate
in the 1975 Survey and most of which are further upstream than
40 stream-km (25 miles) from the reservoir. Although not in-
cluded in the lake nutrient budget on pp. 13-14 because of
their distance away these plants probably do contribute some
nutrients to the lake. These sources include: Minden-
Gardnerville Sanitation District, Douglas County Sewer Improve-
ment District #1, Incline Village General Improvement District,
Stewart STP, State of Nevada Medium Security STP, and Carson City
STP (F. Luchetti, personal communication). Further investiga-
tion is needed to access the actual impact of these facilities
on Lahontan Reservoir.
2
The present phosphorus loading of 9.53 g P/m /yr is over
nine times that proposed by Vollenweider (1975) as "eutrophic".
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However, Vollenweiner's model is probably not applicable to
lakes in which epilimnetic light penetration is severely reduced
by the presence of suspended materials in the water columns.
In lakes of this nature, phytoplankton levels may not develop
to potential as a result of light limitation.
2. Nonpoint sources -
The Carson River contributed 69.5% of the total phosphorus
load to Lahontan Reservoir during the sampling year, the Truckee
Canal was estimated to contribute 17.0% of the total, and minor
tributaries and immediate drainage contributed an estimated
13.2%. The Carson River Basin Council of Governments (1974)
reports that pollution problems in the surface waters of the
Carson River above Lahontan Reservoir are severe with phosphorus
levels exceeding the State water quality standards. Sources of
nutrient enrichment in the basin include effluent exported from
Lake Tahoe, agricultural runoff, municipal and industrial point
source contributions and mining discharges. It should be also
noted that estimations of annual nutrient loadings contributed
by septic tanks around Lahontan Reservoir may have been under-
estimated in this report. Additional study to obtain a more
accurate picture of the complete budget for this lake is recommended.
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II. LAKE AND DRAINAGE BASIN CHARACTERISTICS
Lake and drainage basin characteristics are itemized below.
Lake morphometry data were provided by James B. Williams, Jr.
(personal communication). Tributary flow data except for Truckee
Canal (B-l) were provided by the Nevada District Office of the U.S.
Geological Survey (USGS). Outlet drainage area inculdes the lake
surface area. The difference between the Carson River drainage
area plus the lake surface area versus the outlet drainage area is
p
equal to the drainage of the Truckee River (4.325 km ). Much of
the Truckee is diverted to Lahontan Reservoir via the Truckee Canal;
The USGS (L. Bohmer, personal communication) states that in 1975,
113,400 acre-ft of water flowed through the canal past Hazen. From
this volumetric figure it can be calculated that the average annual
flow for the canal in 1975 was 4.35 m3/sec (153.69 cfs). Nutrient
loadings to Lahontan Reservoir for the canal, based upon this
estimated flow value, are included in the lake nutrient budget on
pp. 13-14. Mean hydraulic retention time was obtained by dividing
the lake volume by mean flow of the outlet. Precipitation values
are estimated by methods as outlined in National Eutrophication
Survey (NES) Working Paper No.175. A table of metric/English con-
versions is included as Appendix A.
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A. Lake Morphometry:
2
1. Surface area: 19.69 km .
2. Mean depth: 6.7 meters.
3. Maximum depth: 31.7 meters.
4. Volume: 131.161 x 10b m3.
5. Mean hydraulic retention time: 91 days.
B. Tributary and Outlet:
(See Appendix B for flow data)
1. Tributaries -
Drainage Mean Flow
Name area (km2) (nvVsec)
A-2 Carson River 4,229.5 12.41
B-l Truckee Canal — 4.35
Minor tributaries and
immediate drainage - 801.3 0.20
Total 5,030.8 16.96
2. Outlet - A-l Carson River 9,375.8 16.62
C. Precipitation:
1. Year of sampling: 8.4 cm.
2. Mean annual: 12.0 cm.
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III. LAKE WATER QUALITY SUMMARY
Lahontan Reservoir was sampled three times during the open-water
season of 1975 by means of a pontoon-equipped Huey helicopter. Each
time, samples for physical and chemical parameters were collected
from four stations on the lake and from one or more depths at each
station (see map, page v). During each visit, depth-integrated
samples were collected from each station for chlorophyll a_ analysis
and phytoplankton identification and enumeration. During the first
and last visits, 18.9-liter depth-integrated samples were composited
for algal assays. Maximum depths sampled were 24.4 meters at Station
01, 21.3 meters at Station 02, 13.1 meters at Station 03, and 7.6
meters at Station 04. For a more detailed explanation of NES methods,
see NES Working Paper No. 175.
The results obtained are presented in full in Appendix C and
are summarized in III-A for waters at the surface and at the maximum
depth for each site. Results of the phytoplankton counts and chloro-
phyll a^ determinations are included in III-B. Results of the limiting
nutrient study are presented in III-C.
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LU-1UA , W S - t »£.-•» V ' .
STO»ET CODE 3?02
PHYSICAL AND CHEMICAL CHARACTERISTICS
( 3/17/7S ) ( 7/ 9/75 )
( ll/ 7/75 )
PA^.ETEP
TEMPERATURE (OEfi
O.-l.S M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN
0.-1.5 M DEPTH
MAX DEPTH**
CONDUCTIVITY ((("H
O.-l.S M. DEPTH
MAX DEPTH**
»*
CFNT)
a
4
("G/LJ
8
4
0*1
8
4
<;***
&ANGE
5.8- «.4
5.7- ft.f,
10.0- 10.6
10.4- 10.4
220.- 327.
217.- 327.
= 4
7.0
6.7
10. <•
10.4
?4A.
?46.
DEPTH
0.0-
4.6-
0.0-
4.6-
n.o-
4.6-
1.5
24.4
1.5
24.4
1.5
24.4
p.
4
7
3
8
4
S**»
WANGE
20.0-
14.0-
6.8-
4.6-
7.-
*>•-
24.0
17.0
6.4
5.8
30.
14.
= 4.
MEDIAN
22.0
15.3
8.0
5.2
14.
11.
MAX
DEPTH
(METEP.S)
0.0- 1.5
7.6- 24.4
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 24.4
N»
7
4
7
4
7
4
PANGF
11.7- n.3
11.7- 13.9
8.2- 9.*
7.4- 9.4
139.- 169.
137.- 169.
= 4
MEOUN
12.5
12.3
8.6
8.4
141.
1*3.
MAX
DEPTH
RANGE
(METERS)
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 20.7
PH (STANDARD UNITS)
O.-l.S M DEPTH
MAX DEPTH**
TOTAL ALKALINITY
O.-l .5 M DEPTH
MAX DEPTH**
TOTAL P (MG/L>
O.-l.S M DEPTH
MAX DEPTH**
DISSOLVED OPTHO P
O.-l.S M DEPTH
MAX DEPTH**
N02*N03 (Mfi/L)
O.-l.S " DEPTH
MAX DEPTH**
AMMONIA (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
KJELOAHL N (MG/L)
O.-l.S M DEPTH
"AX DEPTH**
8
4
(MG/L)
8
4
8
4
(MG/L)
8
4
8
4
8
4
ft
4
7.8- 8.7
8.0- 8.6
88.- 123.
93.- 113.
0.143-0.323
n. 188-0. 231
0.136-0.216
0.121-0.198
0.0*0-0.600
0. 080-0. &00
0.020-0.030
0.020-0.030
0.200-0.400
0.300-0.300
B.I
B.I
104.
I'M .
O.?l i
0.212
0.186
0.174
0.40Q
0.480
0.030
0.030
O.?00
0.30H
0.0-
4.6-
0.0-
4.6-
0.0-
4.6-
0.0-
4.6-
0.0-
4.6-
0.0-
4.6-
0.0-
4.6-
1.6
24.4
l.S
24.4
1.5
24.4
l.S
24.4
1.5
24.4
l.S
24.4
1.5
24.4
8
3
8
3
8
3
H
3
fl
3
8
3
8
3
8.0-
7.5-
63.-
54.-
0.092-0
0.167-0
0.068-0
0.112-0
0.030-0
0. 130-0
0.030-0
0.030-0
0.300-0
0.300-0
8.7
7.7
86.
75.
.143
.290
.096
.161
.050
.190
.070
.080
.400
.500
8.4
7.6
76.
68.
0.134
0.320
O.OH9
0.119
0.025
0.140
0.040
0.060
0.300
0.300
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
0.0- 1.5
7.6- 21.3
7
4
7
4
7
4
7
4
7
4
7
4
7
4
7.3- 7.8
7.6- 7.8
73.- 90.
69.- 91.
0.181-0.220
0.189-0.264
0.130-0.157
0.120-0.160
0.120-0.360
0.120-0.360
0.020-0.020
0.020-0.040
0.200-0.400
0.200-0.400
7.7
7.7
85.
90.
0.196
0.212
0.149
0.142
0.340
0.360
0.020
0.020
0.200
0.200
0.0- 1*5
0.0- 20.7
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 30.7
0.0- 1.5
0.0- 20.7
0.0- 1.5
0.0- 20.7
SECCHT DISC
0.5- 0.8
0.?
0.7- 1.6 0.9
0.3- 0.6 0.3
* N = NO. OF SAMPLES
«* MAXIMUM DEPTH SAMPLED AT tACh SITE
»«* S = NO. OF SITES SAMPLED ON TH!<: DATE
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B. Biological Characteristics:
1. Phytoplankton -
Sampling
Date
03/17/75
07/09/75
11/07/75
Dominant
Genera
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
Centric diatom
Nitzschia
Chroomonas?
Chlamydomonas
Dactylococcopsis
Other genera
Total
Fragilaria
Chroomonas?
Melosira
Asterionella
Schroederia
1.
2.
3.
4.
5.
Other genera
Total
Nitzschia
Centric diatom
Chroomonas?
Navicula
Melosira
Other genera
Total
Algal
Units
Per ml
684
650
308
171
68
103
1,984
3,646
413
413
69
69
4,610
316
158
158
158
105
264
1,159
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2. Chlorophyll a_ -
Sampling Station Chlorophyll
Date Number (yg/1 )
03/17/75 01 2.7
02 2.5
03 4.7
04 14.7
07/09/75 01 5.1
02 6.8
03 3.0
04 . 4.2
11/07/75 01 1.7
02 1.3
03 2.2
04 6.4
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10
C. 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/1-dry wt.)
a. 03/17/75
Control 0.155 0.360 10.6
0.05 P 0.205 0.360 10.3
0.05 P + 1.0 N 0.205 1.360 32.3
1.00 N 0.155 1.360 31.0
b. 11/07/75
Control 0.135 0.255 8.4
0.05 P 0.185 0.255 8.6
0.05 P + 1.0 N 0.185 1.255 24.1
1.00 N 0.135 1.255 24.3
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11
2. Discussion -
The control yields of the assay alga, Selenastrum capri-
cornutum*, indicate that the potential for primary productivity was
high during both sample collection times (03/17/75, 11/07/75).
The addition of nitrogen alone and in combination with phosphorus
produced a significant increase in yield over that of the control
indicating nitrogen limitation. Spikes of only phosphorus did not
stimulate growth significantly beyond control yields.
The mean N/P ratios in the lake data were 2/1 or less on the
three sampling occasions also suggesting primary limitation by
nitrogen (a mean N/P ratio of 14/1 or greater generally reflects
phosphorus limitation).
*For further information regarding the algal assay test procedure
and selection of test organisms, see U.S. EPA (1971).
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12
IV. NUTRIENT LOADINGS
(See Appendix D for data)
For the determination of nutrient loadings, the Nevada National
Guard collected monthly near-surface grab samples from each of the
tributary sites indicated on the map (page v), except for the high
runoff months of May and June when two samples were collected. Samp-
ling was begun November 1974, and was completed in November 1975.
Through an interagency agreement, stream flow estimates for
the year of sampling and a "normalized" or average year were provided
by the Nevada District Office of the USGS for the tributary sites
except for Truckee Canal (B-l), nearest the lake.
In this report, nutrient loads for sampled tributaries, except
Truckee Canal (B-l), were determined by using a modification of a
USGS computer program for calculating stream loadings. Nutrient
loads indicated for tributaries are those measured minus known point
source loads, if any. Nutrient loads for the Truckee Canal were
calculated by multiplying the average annual flow times the respective
mean total phosphorus and mean total nitrogen (N02 - NO., + Kjel)
levels in the canal.
Nutrient loadings for unsampled "minor tributaries and immediate
drainage" ("ZZ" of USGS) were estimated by using the mean annual
2
nutrient loads, in kg/km /year, in Carson River at Station A-2 and
2
multiplying the means by the ZZ area in km .
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13
A. Waste Sources:
1. Known municipal - None
2. Known industrial - None
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs -
% of
Source kg P/yr total
a. Tributaries (nonpoint load) -
A-2 Carson River 130,470 69.5
B-l Truckee Canal 31,965 17.0
b. Minor tributaries and immediate
drainage (nonpoint load) - 24,840 13.2
c. Known municipal STP's - None
d. Septic tanks* - 5 <0.1
e. Known industrial - None
f. Direct precipitation** - 345 0.2
Total 187,625 100.0%
2, Outputs - A-l Carson River 97,485
3. Net annual P accumulation - 90,140
*Estimate based on 3 campgrounds.
**Estimated (See NES Working Paper No.175).
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14
C. Annual Total Nitrogen Loading - Average Year:
1. Inputs -
% of
Source kg N/yr total
a. Tributaries (nonpoint load) -
A-2 Carson River 548,245 64.2
B-l Truckee Canal 180,530 21.1
b. Minor tributaries and immediate
drainage (nonpoint load) - 104,170 12.2
c. Known municipal STP's - None
d. Septic tanks* - 210 <0,1
e. Known industrial - None
f. Direct precipitation** - 21,255 2.5
Total 854,410 100,0%
2. Outputs - A-l Carson River 749,840
3. Net annual N accumulation - 104,570
*Estimate based on 3 campgrounds.
**Estimated (See NES Working Paper No. 175).
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15
D. Mean Annual Nonpoint Nutrient Export by Subdrainage Area:
2 2
Tributary kg P/km /yr kg N/km /yr
Carson River 31 130
E. Mean Nutrient Concentrations in Ungaged Streams:
Mean Total P Mean Total N
Tributary (mg/1) (mg/1)
B-l Truckee Canal 0.233 1.316
C-l Unnamed Creek 0.438 2.500
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16
F. Yearly Loadings:
In the following table, the existing phosphorus annual loading
is compared to the relationship proposed by Vollenweider (1975).
Essentially, his "eutrophic" loading is that at which the receiving
waters would become eutrophic or remain eutrophic; his "oligotrophic"
loading is that which would result in the receiving water remaining
oligotrophic or becoming oligotrophic if morphometry permitted. A
"mesotrophic" loading would be considered one between "eutrophic"
and "oligotrophic".
Note that Vollenweider's model may not apply to lakes with
short hydraulic retention times or in which light penetration is
severely restricted by high concentrations of suspended solids in
the surface waters.
Total Yearly
Phosphorus Loading
(g/irl/yr)
Estimated loading for Lahontan Reservoir 9.53
Vollenweider's "eutrophic" loading 1.00
Vollenweider's "oligotrophic" loading 0.50
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17
V. LITERATURE REVIEWED
Bohmer, L. 1977. Personal communication (flow for Truckee Canal).
U.S. Geological Survey, Carson City, Nevada.
Carson River Basin Council of Governments, 1974. Regional Water
Quality Plan, Phase I, Existing Conditions, Carson River Basin.
Carson City, Nevada.
Luchetti, F. 1977. Personal communication (sewage treatment
plants). Nevada Environmental Protection Service, Carson City,
Nevada.
U.S. Environmental Protection Agency. 1971. Algal Assay Procedure
Bottle Test. National Eutrophication Program, Corvallis, Oregon.
U.S. Environmental Protection Agency. 1975. National Eutrophica-
tion Survey Methods 1973-1976. Working Paper No. 175. National
Environmental Research Center, Las Vegas, Nevada, and Pacific
Northwest Environmental Research Laboratory, Corvallis, Oregon.
Vollenweider, R. A. 1975. Input-Output Models With Special
Reference to the Phosphorus Loading Concept in Limnology.
Schweiz. Z. Hydrol. 37:53-84.
Williams, James B., Jr. 1974. Personal communication (lake mor-
phometry). Department of Human Resources, Carson City, Nevada.
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18
VI. APPENDICES
APPENDIX A
CONVERSION FACTORS
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CONVERSION FACTORS
Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
Cubic meters x 0.107 x 10"^ = acre/feet
Square kilometers x 0.3861 - square miles
Cubic rnoters/sec x 35.315 = cubic feet/sec
Centimeters x 0.3937 = inches
Kilograms x 2.205 r- pounds
Kilograms/square kilometer x 5.711 - Ibs/squarc mile
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APPENDIX B
TRIBUTARY FLOW DATA
-------
TKlfclUTAHY FLOW INFORMATION FOrt NEVADA
LAKE CODE 3202 L.AHONTAN RESEKVOik
TOTAL DRAINAGE AREA OF LAKE
-------
APPENDIX C
PHYSICAL AND CHEMICAL DATA
-------
STORET RETRIEVAL DATE 77/01/26
NATL EUTrtOPHICATJON SURVEY
EPA-LAS VEGAS
320201
39 27 25.0 119 04 06.0 3
LAHONTAN RESERVOIR
32001 NEVADA
1501^1
/TYPA/AMBNT/L«KE
11EPALES
04001002
0087 FEET DEPTH CLASS
DATE
FROM
TO
75/03/17
75/07/09
75/11/07
DATE
FROM
TO
75/03/17
75/07/09
75/11/07
TIME DEPTH
OF
DAY FEET
10 35 0000
10 35 0005
10 35 0015
10 35 0035
10 35 0055
10 35 0080
11 30 0000
11 30 0005
11 30 0015
11 30 0035
11 30 0055
11 30 0080
09 50 0000
09 50 0005
09 50 0015
09 50 0035
09 50 0068
TIME DEPTH
OF
DAY FEET
10 35 OOOn
10 35 0001
10 35 0005
10 35 0009
10 35 0015
10 35 0035
10 35 0055
10 35 0080
11 30 0000
11 30 0005
11 30 0015
11 30 0035
11 30 0055
09 50 0000
09 50 0005
09 50 0015
09 50 0035
09 50 0068
00010
MATER
TEMP
CENT
5.9
5.8
5.9
5.9
5.8
5.7
22.0
21.0
20.0
17.0
16.0
14.0
12.6
12.5
12.5
12.6
12.5
00665
PHOS-TOT
MG/L P
0.216
0.217
0.223
0.223
0.226
0.231
0.092
0.107
0.101
0.132
0.148
0.196
0.181
0.184
0.189
0.189
00300
DO
MG/L
10.6
10.4
10.6
10.4
10.4
10.4
8.0
8.0
5.6
8.6
8.6
8.6
8.6
8.6
32217
CHLRPHYL
A
UG/L
2.7
5.1
1.7
00077 00094
TRANSP CNDUCTVY
«;£CCHI FIELD
INCHES MICHOMHO
33 225
221
221
223
220
217
64 20
20
20
18
16
14
24 139
139
137
137
137
00031
INCDT LT
RFMNING
PERCENT
50.0
1.0
00400
PH
su
7
7
7
8
8
8
8
8
8
8
7
7
7
7
7
7
.90
.85
.95
.05
.10
.10
.70
.70
.70
.00
.80
.30
.50
.60
.65
.70
00410
T ALK
CAC03
MG/L
97
103
88
98
89
96
84
86
85
85
85
76
73
71
68
69
00610
NH3-N
TOTAL
M6/L
0.030
0.020
0.020
0.030
0.020
0.020
0.040
0.030
0.020
0.040
0.040
0.0?0
0.020
0.030
0.030
0.040
00
00625
TOT KJEL
N
MG/L
0.200
0.200K
0.200K
0.200K
0.200K
0.200K
0.400
0.400
0.400
0.300
0.300
0.400
0.300
0.300
0.200
0.200
00630
N02&N03
N-TOTAL
MG/L
O.fcOO
0.^00
0.^90
O.iSOO
O.S90
o.froo
0.020K
0.0?OK
0.020K
0.080
0.140
0.350
0.350
0.350
0.350
0.360
00671
PHOS-DIS
OUTHO
MG/L P
0.204
0.216
0.193
0.214
0.189
0.187
0.068
0.076
0.080
0.099
0.114
0.156
0.157
0.156
0.163
0.160
K VALUE KNOWN TO BE LESS
-------
STOHET RETRIEVAL DATE 77/01/26
NftTL EUTROPHlCATION SURVEY
EPA-LAS VEGAS
/TYPA/AM8NT/LAKE
32030*
39 25 42.0 119 05 12.0 3
LAHONTAN RESERVOIR
32001 NEVADA
11EPALES 04001002
007* FEET DEPTH CLASS 00
DATE
FROM
TO
75/03/17
75/07/09
75/11/07
DATE
KROf
TO
75/03/17
75/07/09
75/11/07
TIME DEPTH
OF
DAY FEET
11 25
11 25
11 25
11 25
11 25
11 25
12 30
12 30
12 30
12 30
12 30
12 30
09 25
09 25
09 25
09 25
09 25
0000
0005
0015
0035
0055
0070
0000
0005
0015
0030
0050
0070
0000
0005
0015
0035
005B
TIME DEPTH
OF
DAY FEET
11 25
11 25
11 25
11 25
11 25
11 25
11 25
11 25
11 25
12 30
12 30
12 30
12 30
12 30
12 30
09 25
09 25
09 25
09 25
09 25
0000
0001
0004
0005
000ft
0015
0035
0055
0070
0000
0005
0015
0030
0050
0070
0000
0005
0015
0035
0058
00010
MATER
TEMP
CENT
6.3
6.7
6.7
6.7
6.7
6.2
22.5
22.0
19.0
17.0
16.0
15.5
13.3
13.1
13.1
13.1
12.9
00665
PHOS-TOT
MG/L P
0.22?
0.223
0.226
0.218
0.216
0.222
0.123
0.131
0.113
0.125
0.157
0.220
0.196
0.182
0.201
0.261
0.264
00300
00
MG/L
10.4
10.4
10.4
10.6
10.6
10.4
8.4
7.8
6.8
6.0
4.6
8.6
8.6
8.2
8.4
7.4
32217
CHLRPHYL
A
UG/L
00077 00094
TRANSP CNDUCTVY
SECCHI FIELD
INCHES MKROMHO
33 224
220
225
224
224
220
36 14
14
16
16
14
12
14 141
141
143
141
158
00031
IMCDT LT
PF.MNING
PFKCENT
00400
PH
su
8.10
8.10
8.10
8.10
8.00
8.00
8.50
8.50
8.60
8.60
7.80
7.70
7.70
7.70
7.70
7.70
7.60
00410
T ALK
CAC03
MG/L
88
90
92
91
93
93
74
77
96
87
85
75
84
86
86
86
91
K VALUE KNOWN TO BE
2.5
6.8
1.3
50.0
5.0
1.0
THAN
INDICATED
00610
NH3-N
TOTAL
MG/L
0.020
0.020
0.030
0.040
0.040
0.030
0.040
0.040
0.030
0.040
0.050
0.030
0.020K
0.020K
0.020K
0.020K
0.020K
LESS
00625
TOT KJEL
N
MG/L
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.300
0.300
0.300
0.300
0.300
0.300
0.200
0.200
0.200
0.200
0.400
00630
NO?kN03
N-TOTAL
MG/L
0.590
0.590
0.600
0.600
O.f 00
0.590
0.020
0.020K
0.020K
0.060
0.130
0.190
0.320
0.310
0.300
0.310
0.360
00671
PHOS-DIS
0«THO
MG/L P
0.188
0.187
0.212
0.197
0.198
0.198
0.090
0.089
0.078
0.092
0.108
0.161
0.146
0.145
0.148
0.127
0.137
-------
STOKET RETRIEVAL D«TE 77/01/26
NATL EUTSOPhlCATIOW SURVEY
EPA-LAS VEGAS
/TYPA/AM8NT/LAKE
DATE
FROM
TO
75/03/17
75/07/09
75/11/07
TIME
OF
DAY
12 00
12 00
12 00
12 00
12 00
11 25
11 25
11 25
11 25
09 00
09 00
09 00
09 00
DEPTH
FEET
0000
0005
0015
0030
0043
0000
0005
0015
0030
0000
0005
0015
0030
00010
tfATER
TFMP
CENT
7.4
7.3
7.1
7.1
7.1
22.0
20.0
17.0
15.0
12.5
12.5
12.4
12.2
320203
39 24 30.0 119 09 57.0
LAHONTAN RESERVOIR
32019 NEVADA
150191
11EPALES
04001002
00*7 FEET DEPTH CLASS
00300
DO
MG/L
10.4
10.4
10.4
10.4
10.4
8.0
7.4
6.6
5.8
8.2
8.2
8.0
8.2
00077
TWANSP
SECCHI
INCHES
21
36
11
00094
CNDUCTVY
FIELD
MICROMHO
267
267
262
271
272
18
14
12
10
163
165
165
167
00400
PH
su
8.20
8.25
8.20
fl.20
8.20
8.30
8.00
7.70
7.60
7.70
7.70
7.70
7.70
00410
T ALK
CAC03
MG/L
115
123
127
116
113
80
68
68
68
85
86
89
90
00610
NH3-N
TOTAL
MG/L
0.030
0.030
0.030
0.030
0.030
0.040
0.060
0.060
0.060
0.020K
0.020K
0.020K
0.020K
00
00625
TOT KJEL
N
MG/L
0.200K
0.200*
0.200K
0.200K
0.200K
0.300
0.300
0.200
0.200
0.200
0.300
0.300
0.200
00630
N02&.N03
Kt-TOTfiL
MG/L
0.390
0.380
0.370
0.170
0.370
0.030
0.050
0.090
0.140
0.140
0.360
0.360
0.360
00671
PHOS-DIS
ORTHO
MG/L C
0.186
0.186
0.199
0.177
0.162
0.090
0.096
0.104
0.112
0.150
0.149
0.150
0.148
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/03/17 12 00 0000
12 00 0005
12 00 0006
12 00 0015
12 00 0030
12 00 0043
75/07/09 11 25 0000
11 25 0005
11 25 0015
11 25 0030
75/11/07 09 00 0000
09 00 0005
09 00 0015
09 00 0030
0665
S-TOT
/L P
0.208
0.207
0.205
0.200
0.202
0.138
0.141
0.136
0.167
0.212
0.220
0.214
0.220
32217
CHLRPHYL
A
UG/L
4.7
3.0
2.2
00031
INCDT LT
RFMNING
PFRCENT
1.0
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/26
NATL EUTROPHICATION
EPA-LAS VEGAS
/TYPA/AM8NT/LAKE
DATE
FROM
TO
75/03/17
75/07/09
75/11/07
TIME DEPTH
OF
DAY FEET
12 45 0000
12 45 0005
12 45 0015
14 00 0000
14 00 0005
14 00 0015
14 00 002S
08 45 0000
00010
WATER
TEMP
CENT
8.4
8.1
8.0
24.0
22.0
18.0
17.0
11.7
00300 00077
DO TRANSP O
SECCHI FIELD
MG/L INCHES Ml
10.4
10.0
10.4
7.0
6.8
5.8
5.2
9.4
24
28
11
320204
39 22 07.0 119 08 40.0 3
LAHONTAN RESERVOIR
32019 NEVADA
1S0191
11EPALES 04001002
0017 FEET DEPTH CLASS 00
94
TVY
MHO
327
327
327
8
7
6
5
169
00400
PH
su
8.70
8.70
8.65
8.40
8.00
7.60
7.50
7.80
00410
T ALK
CAC03
MG/L
104
113
105
63
62
61
54
00
00610
NH3-N
TOTAL
MG/L
0.020
0.020
0.030
0.050
0.070
0.110
0.080
0.020K
00625
TOT KJEL
N
MG/L
0.400
0.400
0.300
0.400
0.300
0.400
0.500
0.200
00630
N02&N03
N-TOTAL
MG/L
0.040
0.050
0.080
0.030
0.040
0.100
O.)30
0.120
00671
PHOS-OIS
OSTHO
MG/L P
0.126
0.126
0.121
O.OS9
O.OS8
0.097
0.119
0.120
00665
DATE TIME DEPTH PHOS-TOT
FROM OF
TO DAY FEET MG/L P
75/03/17 12 45 0000 0.194
12 45 0001
12 45 0004
12 45 0005 0.183
12 45 0007
12 45 0015 0.188
75/07/09 14 00 0000 0.142
14 00 0005 0.149
14 00 0015 0.160
14 00 0025 0.290
75/11/07 08 45 0000 0.205
32217
CHLRPHYL
A
UG/L
14.7
00031
INCDT LT
PF.MNING
PERCENT
50.0
s.o
4.2
6.4
1.0
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
APPENDIX D
TRIBUTARY AND WASTEWATER
TREATMENT PLANT DATA
-------
Kh r«It~\/A,L U
•..T-".^r-ICiTI.j
A "> •/1 o A ^
T I "it
ro
OAV
20
75/01/H 09 50
07 25
0^ 40
U
10
1'+
75/07/12 11
7^/'>-Tn CLASS 00
NU?sNO?
N-TdTflL
Mf,/l_
I..24*.
0.3^?
|>.3S?
0.360
IU410
u .540
J . 2 5 n
O./'nO
•1. t P"^
n . o c, ^
0.140
O.fi^c
M . 1 1 =,
(1.3 on
T:jT KjtL
.4
M,-,/L
O.«00
0.900
1.200
2. 100
u.ttSO
1 .050
2.000
1 .300
1 .250
0.550
0.500
0.^00
0.400
0.500
OOnlO
•Jr. 3-!v
TiiTftL
•'Ci/1.
0.040
0.155
(i . U 4 b
0.0*5
ft . 0 2 0
0.02-5
0.045
0.070
O.»i77
0 . (I 1 u
0.035
0.040
O.OOs
0.030
00671 00665
^HOS-niS °i~ir>S-TOT
O-iTnO
iMr,/L k
0.155
0.160
0.167
0 . 1 (•• 0
0.1 P5
0. lc«5
0.165
0.160
0.1 15
0.115
0.115
n . 1 1 5
0.150
x
-------
A?
/TYP A/A '-' T/«T-€ 4--
OOf 10
OcTf
f-'C, '
10
74/11/23
74/12/19
75/01/11
7S/02/02
7S/1J/08
75/nfc/04
7-5/OS/17
?'?/f!5/26
75/06/0^
7^/Ofi/2?
75/07/lt
fs/nn/in
7s/0-*/l 3
75/1 1/2?
Tit.
ii*
'-J4'
10
10
111
09
16
1<>
10
13
14
IS
09
H>
11
14
••E OEPT-
•• *•; 1 1
OS
oo
?0
53
00
20
s^
0')
on
00
2b
4S
00
31
,M(lPi..N(l 3
M-Ti.Ti(.
M,-,/L
'•.144
o . 2 ^ a
0 . 4 1 «,
O.SIO
0.41')
•.>."! 7S
• i.l«n
>!. ia^
0 • " S S
U.0»0
0 . 1 1 b
'..010
0.020
o.?so
TOT KJEL
N
Mfi/L
O.liOu
1.900
l.7"0
1.^00
O.'ibO
1.200
2.100
0.6t>0
0.4^0
U.55.0
1.100
0.300
0.300
\n H-t^
TOT iL
MI-/L
O.U20
0.04s
0. 144
0.1 ?5
0.0?0
1 .0 1 'i
0. 1^0
O.!'?0
0.045
0 . 0 1 0
O.Olo
0.0 ?b
0.005K
0.003
PnOS-iiIS
ij^T-iu
MG/L H
n.lSS
•I. 145
0. IvO
0.230
0.1*b
o. IKS
0.07S
O.OhO
?. f30
0 . 0 a 0
0.160
0.120
0.135
0.165
PrlOS-T'iT
f«G/L »
0.200
0.250
0.300
0 . .1 1 0
0.310
o.26 03.0 4
Ui/Fw
1-S CHWCHLL -iJTTt
U*'TaN -UHI
(ll\i US HT Sib .h MI St ')H -JCT M»tY
LtS 040010n'»
FtST OEHlh CL4SS 00
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
i.if-
/ T Y •• .1 / i, . r,. : T / S f J ? J •'
J -'• T r T I H E '
rJ.fl .'>
CM ufll f
'' 4 / I I / 2.1 'i--> 3 ?
nw 0*1
<)9 40
09 is
7c/r, 3/OH a1* 1 J-
7 s /, i <» / 0 4 09 3 S
7H/'!-,/! / 11 4",
13 2n
14 Vi
f. 7/1,- 11 07
7S/14/1-. 11 1^
75/OV/13 11 40
7S/H/22 IS In
0 0 h '' 1 1
.NO?. \>03
N-T'-TM.
M(,/L
;i .t.i?
i.b^?
n . o o i-
(.."'7^
O.b7^
0.010
•) . OSc,
".OSO
.i.l/ 1 -
•«.? M
0.017
,..?:I1
• 1. UD
o . o l o
(1 0 6 7 h
TOT KJ£L
-\
'•»b/L
0.700
2.400
1.900
0.800
2.701'
O.QO'J
0.300
O.?b0
0.44 i
0.6^.1
O.-^OO
1 .TOO
0.700
1.700
00610
MMT-.V,
TOT^L
*v/L
0.110
0.230
0.2«^
n.3no
0. 130
0 . 0 1 0
O.'j?il
O.n?3
0 . 0 0 S
o.oob
0 . I) 1 3
0.020
0.012
0 . 0 1 0
00»571
PHOS-OIS
OwTHO
M(i/L P
0.220
0.240
0.220
0.220
0.210
0.120
O.OSQ
0. 17h
0.11^
0.145
n.iis
0.200
0.10S
jv 2M m.n i iv o j bO.o 4
TwnCKFr CA^AL
3? 1 -> SlLVfw so**GS
0/L*hONTAN KtSfcHVUI*' 1^
MhiiR OM oS -T bn .3 MI N OF
HtKuLt? 0400100
0000 FEET HFMTH CLASS nn
OOf *,S
ot-OS-TOT
Mfi/L i^
0.220
0.270
0.3VO
0.310
0.270
0.24*
0.0-»0
0.0«0
0.21S
0.170
0.240
0.210
0.360
0.130
-------
/ T Y P A / A •-• y fvi T / M '-• f.'
TO
l)Gf>30 OO&aS 00610
TIME JtPT-i <-Jf)?vN03 TOT KJtL Mh3-\
OP Ni-r-'.TflL N TOTAL
HAY FKET MG/L
1 n is
7S/04/Q4 11 10
0.900
0.8SO
1.950
0.360
ot. is. a 1 1 •> ^3 oo.o
tU C^-Et",
15 CU'-H/
" >i« Of- JCT
0
0000 FEET OEt-TM CLflSS 00
MG/L
0.480
0.396
-------
APPENDIX E
PARAMETRIC RANKINGS OF LAKES
SAMPLED BY NES IN 1975
STATE OF NEVADA
Mean or median values for six of the key parameters evaluated
in establishing the trophic conditions of Nevada lakes sampled are
presented to allow direct comparison of the ranking, by parameter,
of each lake relative to the others. Median total phosphorus, median
inorganic nitrogen and median dissolved orthophosphorus levels are
expressed in mg/1. Chlorophyll a_ values are expressed in yg/1. To
maintain consistent rank order with the preceding parameters, the
mean Secchi disc depth, in inches, is subtracted from 500. Similarly,
minimum dissolved oxygen values are subtracted from 15 to create
table entries.
-------
LAKE DATA TO BE USED IN RANKINGS
LAKE
CODE LAKE NAME
3201 LAKE MEAD
3202 LAHONTAN RESERVOIR
3204 RYE PATCH RESERVOIR
3205 LAKE TAHOE
3206 TOPAZ RESERVOIR
3207 UPPER PAHRANGAT LAKE
3203 WASHOE LAKE
3209 WILD HORSE RESERVOIR
3210 WILSON RESERVOIR
3211 WALKER LAKE
MEDIAN
TOTAL P
0.016
0.19S
0.094
0.005
0.057
0.173
0.403
0.114
0.049
0.602
MEDIAN
INORG N
0.340
0.350
0.050
0.040
0.165
0.125
0.130
0.320
0.120
0.080 .
500-
MEAN SEC
266.565
472.083
467.750
-3.269
376.000
470.000
494.555
439.400
197.333
405.333
MEAN
CHLORA
3.111
4.608
4.938
0.571
7.517
—
11.633
75.530
10.033 .
3.422
15-
MIN DO
11.400
10.400
10.000
10.200
14.600
3.600
7.200
14.600
11.400
15.000
MEDIAN
DISS ORTHO P
0.005
0.148
0.039
0.003
0.041
0.026
0.268
0.065
0.016
0.574
-------
PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES)
LAKE
CODE LAKE. HAI1E
3201 LAKE MEAD
3202 LAHONTAN RESERVOIR
3204 RYE PATCH RESERVOIR
3205 LAKE TAHOE
3206 TOPAZ RESERVOIR
3207 UPPER PAHRANAGAT LAKE
3208 HASHOE LAKE
3209 WILD HORSE RESERVOIR
3210 WILSON RESERVOIR
3211 WALKER LAKE
MEDIAN
TOTAL P
89 (
22 (
56 (
100 (
67 (
33 (
11 (
44 (
73 (
0 (
8)
2)
5)
9)
6)
3)
1)
4)
7)
0}
MEDIAN
I.NORG N
11 (
0 (
89 (
100 (
33 (
56 (
44 (
22 C
67 .{
78 (
1)
0)
8)
9)
3)
5)
4)
2)
6)
7)
500-
MEAN SEC
78 (
22 t
44 (
100 (
67 (
33 (
0 (
11 (
89 (
56 (
7)
2)
4)
9)
6)
3)
0)
1)
8)
5)
flEAN
CHLORA
88 (
63 C
50 (
100 (
38 (
13 (
o C
25 (
75 (
7)
5)
4)
8)
3)
1)
0)
2)
6)
15-
MIN DO
39 (
56 C
78 (
67 (
17 (
89 (
100 (
17 (
39 (
0 (
3)
5)
7)
6)
1)
8)
9)
1)
3)
0)
MEDIAN
DISS ORTHO P
89 (
22 (
56 (
100 (
44 (
67 (
11 (
33 (
78 (
0 C
8)
2)
5)
9)
4)
6)
1)
3)
7)
0)
------- |