U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
LAKEPEAD
CLARK COUNTY, NEVADA
MDHAVE COUNTY, ARIZONA
EPA REGION IX
WORKING PAPER No, 808
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
-------
REPORT
ON
LAKEPEAD
CLARK COUNTY, NEVADA
MOHAVE OMIT, ARIZONA
EPA REGION IX
WORKING PAPER No, 808
WITH THE COOPERATION OF THE
NEVADA ENVIRONMENTAL PROTECTION SERVICE
AND THE
NEVADA NATIONAL GUARD
SEPTEMBER, 1977
-------
REPORT ON LAKE MEAD
CLARK COUNTY, NEVADA
MOHAVE COUNTY, ARIZONA
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
Corvallis, Oregon
Working Paper No. 808
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
September 1977
-------
CONTENTS
Page
Foreword i i
List of Nevada Study Lakes iv
Lake and Drainage Area Map v-vii
Sections
I. Introduction 1
II. Conclusions 2
III. Lake and Drainage Basin Characteristics 6
IV. Lake Water Quality Summary 8
V. Nutrient Loadings 20
VI. Literature Reviewed 26
VII. Appendices 28
-------
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)], 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.
-------
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, who directed
the volunteer efforts of the Nevada National Guardsmen, are
also gratefully acknowledged for their assistance to the Survey.
-------
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
-------
X Lake Sampling Site
Sewage Treatment Facility
V
-------
NorthLasVegas
Las Vegas*'
Henderson*
Boulder City«Q$*%'
\
LAKE MEAD N
Tributary Sampling Site
Sewage Treatment Facility
o so 100 150Km
25 50 75 Mi .
Scale
-------
36* 10'
LAS VEGAS WASH
- 36 05
+55 +56
+54
+S3 BOULDER BASIN
+52
0 1 2 3 4 km.
HOOVER DAM
36' 00*
-------
REPORT ON LAKE MEAD, NEVADA
STORE! NO. 3201
I. INTRODUCTION
Lake Mead is a deep, warm monomictic lake created by the inter-
state impoundment of the Colorado River by Hoover Dam in 1935.
Located in the Mohave Desert, the lake bed consists mainly of sand,
silt and clay but with some expansive areas of soluble beds of
gypsum and rock salt. In the first decade of Lake Mead, solutions
of gypsum and rock salt from the reservoir bed caused the dissolved
mineral content in the outflowing waters to be substantially greater
than the average in the incoming waters. Presently however, increases
in outflowing dissolved mineral content can be attributed to evapora-
tion, which is about 5-7% of the annual inflow in the hot, arid
climate (Thomas, 1954).
One of the largest man made lakes in the United States, Lake
Mead is used extensively for all forms of recreational sports, and
water for public use in the Las Vegas Valley is removed from an
intake in Boulder Basin. Thermal stratification in the lake develops
in May or June, resulting in a classical thermocline between 10-15m
in July. Lake turnover generally begins in October, and the lake
is completely destratified by January or February. During thermal
stratification a negative heterograde oxygen profile develops,
-------
primarily a result of biological respiration at the metalimnion,
and is found in all reaches of the lake (Deacon, 1976).
II. CONCLUSIONS
A. Trophic Condition:*
Survey data indicate that Lake Mead is borderline between
mesotrophic and oligotrophic throughout, with the exception of
the inner Las Vegas Bay and Las Vegas Wash areas, which are
meso-eutrophic and eutrophic, respectively, in water quality.
Las Vegas Wash is considered eutrophic based upon high
nutrient levels and primary productivity. Chlorophyll a_ values
in the lake sampling sites immediately downstream from the Las
Vegas Wash embayment (Stations 09,58,59 and 60) ranged from
2.5 yg/1 to 19.9 yg/1, with a mean of 11.8 yg/1. Total phos-
phorus levels ranged from 0.048 mg/1 - 0.111 mg/1, with a mean
of 0.067 mg/1, and Secchi disc visibility was generally lower at
these stations than was observed elsewhere in the lake except
at the mouth of the Colorado River.
Las Vegas Bay (as represented by Stations 01, 61, 62, 63,
64, 65, 66, and 67) had chlorophyll a_ levels ranging from 1.8
yg/1 to 10.4 yg/1 during the sampling year with a mean of 5.8
yg/1. Total phosphorus levels in this section of the lake
ranged from 0.019 mg/1 - 0.046 mg/1, with a mean of 0.028 mg/1.
*See Appendix E.
-------
The remainder of the lake appears to be in excellent condition.
Of the 10 Nevada lakes sampled in 1975, all but Lake Tahoe had higher
median total phosphorus levels (0.016 mg/1) and higher median ortho-
phosphorus values (0.005 mg/1) than Lake Mead. Mean chlorophyll a_
for the lake was only 3.1 yg/1, and average lake transparency was in
excess of 584 cm (230 in).
Survey limnologists did not report any problem algal blooms or
macrophyte growths during their visits to the lake. However, other
studies (Sawyer, C. N., 1976; Hoffman, D. A., et. al., 1971; Goldman,
C. R., 1976) have reported extensive algal blooms and associated
objectional water color and odors in the Las Vegas Wash. Hoffman
et. al. (1970) noted that the impoundment of Lake Powell upstream
the Colorado River resulted in a temporary acceleration of water
quality deterioration in Lake Mead as a result of lowered water
levels, but that water quality in the lake has improved since the
elevation of Lake Mead has raised.
B. Rate-Limiting Nutrient:
Algal assay results indicate that Lake Mead is primarily
limited by available phosphorus levels. Inorganic nitrogen to
orthophosphorus ratios obtained from the lake data further suggest
phosphorus limitation (N/P > 18/1) on all sampling dates, all stations,
except for in Las Vegas Wash where low ratios (N/P < 10/1) suggest
nitrogen limitation.
-------
C, Nutrient Controllability;
1. Point sources -
During the 1975 sampling year, sampled point sources
contributed 8.7% of the total phosphorus load to Lake Mead.
The Clark County wastewater treatment plant (2 outfalls) con-
tributed a total of 5.7% and the Las Vegas treatment plant
contributed 3.0%. In addition, there are small treatment
plants in the communities of Henderson and Boulder City which
discharge to land irrigation (U.S. EPA, 1971b). How much, if
any, of this land release eventually reaches Lake Mead through
surface runoff is not known at this time. The city of Mesquite
is also a known municipal discharger to the Virgin River.
However, the plant did not participate in the 1975 survey and
it is not known what annual nutrient contributions impact Lake
Mead from this source.
p
The calculated annual phosphorus loading of 6.23 g P/m /yr
is almost an order of magnitude greater than that proposed by
Vollenweider (1975) as "eutrophic" for a lake with such volume
p
and hydraulic retention time (0.78 g P/m /yr). Lake Mead appears
to be acting as an effective nutrient trap, with over 90% of the
phosphorus loading being retained by the lake. However, most
of the nutrients appear to be deposited very near the inlets of
inflowing tributaries. For example, ambient total phosphorus
-------
and total nitrogen (N02 + N03 + Kjeldahl) concentrations
(Appendix C) are substantially less at Station 15 than
those found in the Colorado River at Station A-2 (Appendix D),
and those at Station 05 are similarly less than concentrations
found at Station D-l on the Virgin River. This effective
loading, after consideration of the Lake Mead sedimentation
rate, is still probably in excess of Vollenwei.der's "eutrophic"
level and a progression towards eutrophic conditions in the
lake can be expected. However, the progression should be
relatively slow under present conditions except in Las Vegas
Wash and Las Vegas Bay, where nutrient levels are many times
higher than elsewhere in the lake and are increasing annually
(Deacon, 1976). Substantial reduction of phosphorus loading
from the known point sources to Las Vegas Wash will be neces-
sary to reduce the occurrence of problem conditions, such
as excessive algal populations, which are regularly reported
in this area.
2. Nonpoint sources -
Nonpoint sources, including precipitation, contributed
approximately 91% of the total phosphorus loading during the
sampling year. The Colorado River contributed 80.2% of the
total load, and ungaged tributaries contributed an estimated
5.3%.
-------
III. LAKE AND DRAINAGE BASIN CHARACTERISTICS
Lake and drainage basin characteristics are itemized below,
Lake morphometry data were provided by James B. Williams, Jr. (per-
sonal communication). Tributary flow data were provided by the
Nevada District Office of the United States Geological Survey (USGS).
Outlet drainage area includes the lake surface area. Mean hydraulic
retention time was obtained by dividing the lake volume by mean flow of
the outlet. Precipitation values are estimated by methods as out-
lined in National Eutrophication Survey (NES) Working Paper No. 175.
A table of metric/English conversions is included as Appendix A.
A. Lake Morphometry:
1. Surface area: 592.88 km2.
2. Mean depth: 59.1 meters.
3. Maximum depth: 179.5 meters.
4. Volume: 35,064.420 x 10^ m3.
5. Mean hydraulic retention time: 1,289 days (3,5 yrs).
-------
Tributary and Outlet:
(See Appendix B for flow data)
1. Tributaries -
Drainage Mean Flow
Name area (km2) (m3/sec)
A-2 Colorado River 378,139.9 370.21
C-l Muddy River 21,238.0 0.40
D-l Virgin River 15,255.1 4.82
Minor tributaries and
immediate drainage - 19,376.0 1.91
Total 434,009.0 377.34
2. Outlet - A-1 Colorado River 434,601.8 314.74
Precipitation:
1. Year of sampling: 9.4 cm.
2. Mean annual: 13.1 cm.
-------
IV. LAKE WATER QUALITY SUMMARY
Lake Mead was sampled as part of the National Eutrophication
Survey four 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 15 stations on the lake
and from one or more depths at each station (see maps, pages v-vi )•
In addition, 22 special interest stations throughout Las Vegas and
Boulder Bay (see map, page vii) were collected during the month of
December (12/08-11/75). During each visit, depth-integrated samples
were collected from each station for chlorophyll ^analysis and phyto-
plankton identification and enumeration. During February, November,
and December visits, 18.9-liter depth-integrated samples were com-
posited for algal assays from the original 15 NES sampling stations.
Maximum depths (expressed in meters) sampled at these 15 stations
and at the 22 special study sites in Las Vegas and Boulder Bays were
as follows:
Station
Number (NES)
01 (=31)
02 (=32)
03 (=33)
04 (=34)
05 (=35)
06 (=36)
07 (=37)
08 (=38)
09 (=39)
10 (=40)
Depth
26.2
65.5*
70.1*
61.0*
16.5
45.7
70.0*
67.0*
12.5
70.1*
Station
Number
51
52
53
54
55
56
57
58
59
60
Depth
49.7
64.0*
64.0*
64.0*
51.2
59.7
57.6
9.1
2.1
19,8
indicates actual depth of station exceeding cable length.
Consequently, data from deeper waters were not collected.
-------
11 (=41)
12 (=42)
13 (=43)
14 (=44)
15 (=45)
70.1*
67.0*
68.9*
9.4
6.4
IV. LAKE WATER QUALITY SUMMARY (continued)
Station Station
Number (NES) Depth Number Depth
61 27.4
62 10.7
63 42.7
64 44.2
65 17.7
66 7.6
67 64.0*
68 15.2
70 65.5*
74 67.0
75 61.0
76 37.8
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
chlorophyll ^determinations are included in III-B. Results of the
limiting nutrient study are presented in III-C.
indicates actual depth of station exceeding cable length.
Consequently, data from deeper waters were not collected.
-------
LAKE MEAD
STOKEr CuDE 3201
PARAMETER
N*
PHYSICAL AND CHEMICAL CHARACTERISTICS
( 2/24/75 ) ( 6/11/75 )
MAX MAX
S*»« = 15 DEPTH S*«* = 14 DEPTH
RANGE RANGE
RANGE MEDIAN (METERS) N* RANGE MEDIAN (METERS)
N*
( 11/20/75 )
MAX
S««» = 3^ DEPTH
RANGE
RANGE MEDIAN (METERS)
TEMPERATURE (DEO CENT)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN
0.-1.5 M DEPTH
MAX DEPTH**
28
15
(MG/L)
27
15
CONDUCTIVITY (UMHOS)
0.-1.5 M DEPTH 28
MAX DEPTH" 15
PH (STANDARD UNITS)
0.-1.5 M DEPTH 28
MAX DEPTH** 15
TOTAL ALKALINITY
0.-1.5 M DEPTH
MAX DEPTH**
TOTAL P (MG/L)
O.-l.b M DEPTH
MAX DEPTH**
DISSOLVED ORTHO P
0.-1.5 M DEPTH
MAX DEPTH»«
N02+N03 (MG/L)
O.-i.b M DEPTH
MAX DEPTH**
AMMONIA (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
KJELDAHL N (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
(MG/L)
28
15
28
15
(MG/L)
28
15
28
15
28
15
28
IS
7.5- 11.9
7.1- 10.9
7.2- 13.9
9.0- 14.2
624. -1154.
622. -1198.
8.1- 8.4
8.1- 8.4
133.- 163.
133.- 166.
0.011-0.111
0. 011-0. Ill
0.003-0.070
0.003-0.070
0.340-0.490
0.340-0.500
0.020-0.060
0.020-0.030
0.200-1.800
0.200-U.400
9.2
8.5
10.6
10.4
789.
766.
b.3
8.3
144.
141.
0.020
0.022
0.010
0.013
0.375
0.370
0.02C
0.020
0.300
0.300
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
bl.O
28
14
28
14
28
14
28
13
28
14
28
14
28
14
28
14
28
14
28
14
15.4- 24.7
9.4- 16.9
7.4- 10.0
7.0- 9.8
920. -1268.
849. -1070.
8.3- d.7
8.1- 8.6
128.- 159.
128.- 156.
0.005-0.029
0.005-0.075
0.002-0.017
0.002-0.075
0.080-0.500
6.120-0.520
0.020-0.150
6.020-0.280
0.200-3.300
0.200-0.400
21.4
10.3
9.0
8.4
1198.
920.
8.5
8.3
144.
144.
0.008
0.009
0.003
0.003
0.305
0.400
0.040
0.030
0.450
0.300
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
0.0-
3.7-
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
1.5
61.0
71
34
70
34
71
34
71
34
71
34
71
34
71
34
71
34
71
34
71
34
8.4- 16.7
8.5- 15.7
5.0- 10.6
3.6- 11.6
561.- 900.
646. -1017.
7.2- b.6
7.2- 8.5
117.- 154.
121.- 156.
0.004-0.054
0.004-0.179
0.002-0.019
0.002-0.157
0.020-0.480
0.130-0.560
0.020-0.040
0.02U-0.060
0.200-0.400
0.200-0.300
14.5
13.6
8.6
8.2
800.
789.
8.0
7.8
131.
135.
0.018
0.019
0.005
0.006
0.230
0.400
0.020
0.020
0.200
0.200
0.0- 1.5
2.1- 70.1
0.0- l.b
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
0.0- 1.5
2.1- 70.1
SECCrtI DISC (METERS)
14
0.9-
5.2
13
0.5- 12.2
6.5
0.5- 15.2
4.3
* N = NO. OF SAMPLES
»* MAXIMUM DEPTH SAMPLED AT EACH SITE
»** S = NO. OF SITES SAMPLED ON THIS UMTE
-------
LAKE MEAD
CODE 3201
PARAMETER
PHYSICAL AND CHEMICAL CHARACTERISTICS
N«
( 12/11/75 )
MAA
S««» = <+ DEPTH
RANGE
RANGE MEDIAN (METERS)
TEMPERATURE (DEG CENT)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN
0.-1.5 M DEPTH
MAX DEPTH**
7
4
(MG/L)
8
4
13.9-
11.5-
a.2-
6.2-
14.3
13.7
9.2
7.4
14.1
11.6
8.6
6.5
0.
37.
0.
37.
0-
8-
0-
8-
1.
67.
1.
67.
5
1
5
1
CONDUCTIVITY (UMHOS)
0.-1.5 M DEPTH
MAX DEPTH**
tt
4
791.-
732.-
820.
795.
799.
790.
0.
37.
0-
8-
1.
67.
5
1
PH (STANDARD UNITS)
O.-l.S M DEPTH
MAX DEPTH**
TOTAL ALKALINITY
U.-1.5 M DEPTH
MAX DEPTH**
TOTAL P (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
DISSOLVED ORTHO P
0.-1.5 M DEPTH
MAX uEPTH**
N02«N03 (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
AMMONIA (MG/L)
0.-1.5 M DEPTH
MAX uEPTH**
KJELUAHL N (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
8
4
(MG/L)
b
4
8
4
(MG/L)
8
*
8
4
B
4
8
4
7.9-
7.7-
12J.-
126.-
0.015-0
0.012-0
0.004-0
0.009-0
0.230-0
0.250-0
0.030-0
0.030-0
0.200-0
0.200-0
8.1
8.0
131.
148.
.021
.021
.008
.012
.260
.440
.040
.060
.200
.400
8.0
7.8
126.
144.
O.J18
0.015
0.006
0.009
0.240
0.430
0.035
0.045
0.200
0.200
0.
37.
0.
37.
0.
37.
0.
37.
0.
37.
0.
37.
0.
37.
0-
8-
0-
8-
0-
8-
0-
8-
0-
8-
0-
8-
0-
8-
1.
67.
1.
67.
1.
t>7.
1.
67.
1.
67.
1.
67.
1.
67.
5
1
5
1
5
1
5
1
5
1
5
1
5
1
SECCHI DISC (METERS)
4.3- 6.7
« N = NO. OF
«* MAXIMUM DEPTH SAMPLED AT EACH SITE
»»« S = NO. OF SIT.,5 SAMPLED ON THIS UATE
-------
12
B. Biological Characteristics:
1. Phytoplankton -
Sampling
Date
02/24/75
06/11/75
11/20/75
12/01/75
Dominant
Genera
1. Chroomonas?
2. Cryptomonas
3. Tetraedron
Other genera
Total
1.
2.
1.
1.
2.
Chroomonas?
Rhoicosphenia
Other genera
Total
-. Raphidiopsis
2. Chroomonas?
3. Anabaenopsis
4. Centric diatom
5. Cryptomonas
Other genera
Total
Chroomonas?
Raphidiopsis?
Other genera
Total
Algal
Units
Per ml
511
46
46
603
110
44
154
1,056
624
240
240
96
96
2,352
170
43
213
-------
13
2. Chlorophyll a_ -
Sampling Station Chlorophyll a_
Date Number (yg/1)
02/24/75 01 1.9
02 1.6
03 1.4
04 2.4
05 1.9
06 2.1
07 0.5
08 0.6
09 9.0
10 1.0
11 1.0
12 0.5
13 0.8
14 1.6
15 0.7
06/11/75 01 2.6
02 2.1
03 1.9
04 1.6
05 1.0
06 0.7
07 0.6
08 0.6
09
10 1.2
11 0.5
12 0.8
13 0.8
14 0.7
15 1.1
-------
14
2. Chlorophyll a_ - (continued)
Sampling Station Chlorophyll a
Date Number (yg/1)
11/20/75 01 8.0
02 4.5
03 3.7
04 4.3
05 l.g
06
07
08
09 2.5
10 1.4
11 1.2
12
13 2.2
14 2.1
15 0.7
12/01/75 01
02 4.1
03
04
05
06 1.0
07 0.9
08 0.9
09
10 1.2
11 1.0
12 1.0
13
14
15
-------
15
2. Chlorophyll a_ - Special Study Stations -
Sampling Station Chlorophyll a_
Date Number (yg/1)
12/04,08-11/75 51 3.8
52 2.8
53 4.2
54 3.7
55 3.2, 4.2
56 3.8
57 5.4
58
59 19.9
60 15.6
61 5.9
62 10.4
63 7.0
64 1.8
65 7.6
66 10.0
67 2.6
68 4.0
70 3.1
74 3.2
75 3.2
76 3.4
-------
16
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked -
Spike (mg/1)
Ortho P
Cone, (mg/1)
Inorganic N
Cone, (mg/1)
a. 02/24
Control
0.05 P
0.05 P + 1
1.00 N
Control
0.05 P
0.05 P + 1
1.00 N
Control
0.05 P
0.05 P + 1
1.00 N
Control
0.05 P
0.05 P + 1
1.00 N
b. 11/20
Control
0.05 P
0.05 P + 1
1.00 N
Control
0.05 P
0.05 P + 1.
1.00 N
,25/75 Stations
0.005
0.055
.0 N 0.055
0.005
Stations
<0.005
<0.055
.0 N <0.055
<0.005
Stations
<0.005
<0.055
.0 N <0.055
<0.005
Station 1
<0.005
<0.055
.0 N <0.055
<0.005
,21/75 Stations
0.005
0.055
.0 N 0.055
0.005
Stations
0.005
0.055
.0 N 0.055
0.005
01-04
0.384
0.384
1.384
1.384
05-08
0.354
0.354
1.354
1.354
10-13
0.369
0.369
1.369
1.369
5
0.446
0.446
1.446
1.446
01-03, 09
0.245
0.245
1.245
1.245
04, 10, 11
0.330
0.330
1.330
1.330
Maximum Yield
(mg/1-dry wt.)
0,3
0.4
0.4
0.4
0.1
0.4
0.6
0.1
0.1
0.5
0.6
0,1
0.2
0.2
0.3
0.1
0.7
9.6
21.0
0.6
0.1
9.2
16.6
0.1
-------
17
C. Limiting Nutrient Study; (continued)
1. Autoclaved, filtered, and nutrient spiked
Spike (mg/1)
Ortho P
Cone, (mg/1)
Inorganic N
Cone, (mg/1)
Stations 12,13
Control
0.05 P
0.05 P + 1.0 N
1.00 N
0.005
0.055
0.055
0.005
0.425
0.425
1.425
1.425
c. 12/01-02/75 Stations 06-08
Control 0.005
0.05 P 0.055
0.05 P + 1.0 N 0.055
1.00 N 0,005
0.350
0.350
1.350
1.350
Stations 08, 11, 12
Control 0.005
0.05 P 0.055
0.05 P + 1.0 N 0.055
1.00 N 0.005
0.405
0.405
1.405
1.405
Maximum Yield
(mg/1-dry wt.)
0.1
10.9
13.7
0.1
0.2
8.4
9.2
0.2
0.3
9.9
12.2
0.2
-------
18
2. Discussion -
The control yields of the assay alga, Selenastrum capri-
cornutum*, indicate that the potential for primary productivity
was generally low at the time the NES samples were taken. In most
of the assays, increases in yield over that of the control with the
addition of phosphorus spikes indicate that Lake Mead was limited
by available phosphorus. The addition of nitrogen alone resulted
in yields which were not significantly different than those of the
controls.
The reservoir data substantiate phosphorus limitation; i.e.,
the mean inorganic nitrogen to dissolved orthophosphorus ratios were
18/1 or greater at all stations on all sampling rounds except for
Stations 09, 58 and 60 where N/P ratios were less than 10/1, indicating
nitrogen limitation in that area. These three stations are located
at the mouth of Las Vegas Wash, where phosphorus levels are substan-
tially higher than elsewhere in the lake as a result of upstream dis-
charges of municipal wastewater. These findings support work by the
U.S. Department of the Interior (1970) which presented bioassay data
indicating inorganic phosphorus was limiting algal growth throughout
most of Lake Mead and the Colorado River below the dam. More recent
authors have also suggested that nitrogen is the primary limiting
nutrient throughout inner Las Vegas Bay as a result of the high phos-
phorus loading to that area (Deacon, J. E., 1976; Goldman, C. R., 1976)
*For further information regarding the algal assay test procedure
and selection of test organisms, see U.S. EPA (1971a).
-------
19
from Las Vegas Wash. Unfortunately there was no assay sample col-
lected separately for either Las Vegas Wash or Las Vegas Bay to
substantiate these results.
Several of the algal assays exhibited little or no response to
addition of nutrients (particularly during the February sampling).
Available data were insufficient to determine the cause of these
anomalous results. However, possible explanations include the
presence of a toxin or primary limitation by some minor nutrient
other than nitrogen or phosphorus. Hoffman, et. al. (1971) report
that micronutrients (such as molybdenum), carbon sources, vitamins
and enzymes may be the key factors limiting primary productivity
rather than phosphorus and nitrogen.
-------
20
V. 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 maps (pages v-vi) except for the
high runoff months of March and April when two samples were generally
collected. Sampling was begun in November 1974, and was completed
in October 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 nearest
the lake.
In this report, nutrient loads for sampled tributaries 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 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 the Colorado River and Virgin River
at Stations A-2 and D-l and multiplying the means by the ZZ area in
km2.
The operators of the Las Vegas and the Clark County (East and
West) wastewater treatment plants provided monthly effluent samples
and corresponding flow data. However, flow data provided were
-------
21
from influent gauging stations, and a substantial portion of the
effluent from both plants is diverted for use in irrigation (golf
courses and farms), and for cooling water in the Las Vegas city
power plants. The Clark County Sanitation District reports that
in 1975, 14.23% of the Clark County plants and 13.2% of the City
of Las Vegas plant effluents were diverted; thus, annual loading
data for 1975 to Lake Mead provided to NES have been reduced these
amounts in the lake nutrient budget on pages 22-23. It should be
noted that these diversions may be increasing substantially. For
the months of July, August and September, 1977, the City of
Las Vegas plant reports monthly effluent diversions ranging from
41-54% of the total inflow to the plant. Further investigation
is needed to determine the true annual nutrient loading from
these facilities to Las Vegas Wash.
-------
22
A. Waste Sources:
1. Known municipal -
Name
Las Vegas
Municipal
Clark County
Municipal
(E. Outfall)
Clark County
Municipal
Pop.*
Served
218,000
56,000
56,000
Treatment*
Trickling
Filter
Trickling
Filter
Trickling
Filter
Mean Flow**
(m3/d x 103)
48.926
53.331
41.350
Receiving
Water
Las Vegas Wash
Las Vegas Wash
Las Vegas Wash
(W. Outfall)
Known industrial -
There were no industrial point sources known to impact Lake
Mead which were sampled by NES in the 1975 sampling year. However,
until recently industrial wastes from seven plants were discharged
into a complex of waste disposal ponds operated by Basic Management,
Inc. (BMI). These disposal ponds are unlined, and in 1971 seepage
into Las Vegas Wash was estimated to average more than 5 mgd and to
be a major source of nitrates and dissolved solids to the lake (U.S.
EPA, 1971b). As of January, 1977, all the BMI plants have contained
their discharges in impermeable ponds on their property. However,
contaminated groundwater seepage into the Wash resulting from per-
colation of past industrial discharges into the upper groundwater
aquifer will probably continue for several years (U.S. EPA, 1971 c;
P. King, personal communication).
*Provided by treatment plant operations
** Flows indicated are at influent, rather than effluent stations.
-------
23
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs -
% of
Source kg P/yr total
a. Tributaries (nonpoint load) -
A-2 Colorado River 2,962,270 80.2
C-l Muddy River 4,525 0.1
D-l Virgin River 199,840 5.4
b. Minor tributaries and immediate
drainage (nonpoint load) - 193,760 5.3
c. Known municipal STP's* -
Las Vegas 110,550 3.0
Clark County 119,510 3.2
(East Outfall)
Clark County 91,995 2.5
(West Outfall)
d. Septic tanks** - 10 <0.1
e. Known industrial - See page 20
f. Direct precipitation*** - 10,375 0.3
Total 3,692,835 100.0%
2. Outputs - A-l Colorado River 247,325
3. Net annual P accumulation - 3,445,510
*Adjusted for known effluent diversions.
**Estimate based on 35 lakeshore residences.
***Estimated (See NES Working Paper No. 175).
-------
24
C. Annual Total Nitrogen Loading - Average Year:
1. Inputs -
% of
Source kg N/yr total
a. Tributaries (nonpoint load) -
A-2 Colorado River 24,139,490 89.9
C-l Muddy River 23,085 0.1
D-l Virgin River 302,070 1.1
b. Minor tributaries and immediate
drainage (nonpoint load) - 813,790 3.0
i,. *
c. Known municipal STP's
Las Vegas 322,675 1.2
Clark County 333,245 1 2
(East Outfall)
Clark County 305,600 1.1
(West Outfall)
d. Septic tanks** - 375 <0.1
e. Known industrial - See page 20
f. Direct precipitation*** - 640,075 2.4
Total 26,880,405 100.0%
2. Outputs - A-l Colorado River 11,996,385
3. Net annual N accumulation - 14,884,020
*Adjusted for known effluent diversions.
*Estimate based on 35 lakeshore residences.
**Estimated (See NES Working Paper No. 175).
-------
25
D. Mean Annual Nonpoint Nutrient Export by Subdrainage Area:
O
Tributary kg P/km /.yr kg N/km^/yr
Colorado River 8 64
Muddy River <1 1
Virgin River 13 20
E. 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 is 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/m?/yr)
Estimated loading for Lake Mead 6.23
Vollenweider's "eutrophic" loading 0.78
Vollenweider's "oligotrophic" loading 0.39
-------
26
VI. LITERATURE
Deacon, James E. 1976. Lake Mead Monitoring Program. Final Report
Submitted to Clark County Sanitation District No. 1, Wastewater
Treatment Physical Development Section. Department of Biological
Sciences, University of Nevada, Las Vegas.
Goldman, C. R. 1976. A Review of the Limnology of and Water Quality
Standards for Lake Mead. Ecological Research Associates, Davis,
California.
Hoffman, D. A., P. R. Tramutt, and F. C. Heller. 1970. Water Quality
Study of Lake Mead. Bureau of Reclamation. Chemical Engineering
Branch, Division of Research, Report No. CHE-70. Denver, Colorado.
Hoffman, D. A., P. R. Tramutt, and F. C. Heller. 1971. The Effect
of Las Vegas Wash Effluent Upon the Water Quality in Lake Mead.
Engineering and Research Center, Bureau of Reclamation Report
#REC-ERC-71-11. Denver, Colorado.
King, Peter. 1977. Personal Communication (Las Vegas Valley Sewage
Treatment Plants). U.S. Environmental Protection Agency, Region IX,
Enforcement Division, Water Branch, San Francisco, California.
Sawyer, C. N. 1976. Report on Wastewater Disposal to Board of County
Commissioners, Clark County, Nevada. Consultant, Sun City, Arizona.
Thomas, H. E. 1954. First Fourteen Years of Lake Mead. United States
Geological Survey Circular 346. Washington, D. C.
U.S. Department of the Interior. 1970. Analysis of Algal Growth
Potential and Possible Discharge Requirements for the Lower Colorado
River. (Technical Assistance Report to the State of Nevada, Depart-
ment of Health, Welfare and Rehabilitation). Federal Water Quality
Administration, Colorado River, Bonneville Basin Office, Denver
Colorado.
U.S. Environmental Protection Agency. 1971a. Algal Assay Procedure
Bottle Test, National Eutrophication Research Program, Corvallis,
Oregon.
U.S. Environmental Protection Agency. 1971b. Inventory of Wastewater
Treatment Facilities. EPA Publication No. OWP-1. Office of Media
Programs, Office of Water Programs, Washington, D. C.
-------
27
U.S. Environmental Protection Agency. 1971c. Report on Pollution
Affecting Las Vegas Mash, Lake Mead, and the Lower Colorado River.
Office of Enforcement, Region IX, San Francisco, California, and
Division of Field Investigations, Denver, Colorado.
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. 1974. Personal Communication (morphometry
of Lake Mead). Department of Human Resources, Carson City, Nevada.
-------
28
VII. APPENDICES
-------
APPENDIX A
CONVERSION FACTORS
-------
CONVERSION FACTORS
Hectares x 2.171 = acres
Kilometers x 0.6211 = 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/s.quarc kilometer x 5.711 - Ibs/squarc mile
-------
TRIBUTARY FLOW INFORMATION FOR NEVADA
1/21/77
LAKE CODE 3201
LAKE MEAD
MEAN MONTHLY FLOWS AND DAILY FLOwS(CwS)
TRIBUTARY MONTH YEAR MEAN FLOW DAY
3201C1
3201D1
3201ZZ
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
74
74
75
75
75
75
75
75
75
75
75
75
74
74
75
75
75
75
75
75
75
75
75
75
74
74
75
75
75
75
75
75
75
75
75
75
0.651
0.481
0.255
0.227
0.311
0.396
0.283
0.227
0.198
0.227
0.425
0.5b6
4.701
4.389
3.511
4.531
5.777
2.633
3.908
0.283
0.008
0.014
0.170
0.311
2.832
2.832
2.549
2.832
2.549
2.832
2.265
1.982
3.398
2.549
2.832
1ft
20
2P
20
23
17
30
31
20
23
16
20
29
2n
?3
17
30
31
20
2fl
FLOW DAY
0.680
0.425
0.198
0.340
0.425
0.283
0.198
0.198
0.198
0.566
4.106
4.106
2.832
6.654
0.396
6.796
0.011
0.011
0.014
0.0
28
2V
FLOW DAY
0.368
0.368
FLOW
28
29
5.663
0.736
-------
APPENDIX B
TRIBUTARY FLOW DATA
-------
TRI6UT6KY FLOW INFORMATION FOR NEVADA
1/21/77
LAKE CODE 3201 LAKE MEAD
TOTAL DRAINAGE AREA OF LAKPISO KM) 434601.8
SUB-ORAINAGE
TRIBUTARY AREA(SQ KM)
JAN
FEB
MAR
APR
MAY
NORMALIZED FLOwS(CMS)
JUN JUL AUG
SFP
OCT
NOV
DEC
MEAN
3201A1
320 1A2
3201C1
3201D1
3201ZZ
434601.8
378139.9
21238.0
15255.1
19968.9
226.53
342.63
0.31
6.82
2.83
280.34
271.84
0.31
6.82
2.55
37"?. 78
317.15
0.37
=i.95
?.27
410.59
484.22
0.45
7.93
1.98
410.59
492.71
0.31
5.21
1.4P
368.12
478.55
0.25
1.64
1.42
370.95
399.27
0.23
0.23
1.13
356.79
404.93
0.31
3.68
1.70
297.33
359.62
0.40
3.23
1.42
24b.36
2BO. 34
0.59
3.45
1.70
218.04
2S8.B3
0.74
•=..13
2.?7
215.21
317.15
0.51
7.84
2.27
314.74
370.21
0.40
4.82
1.91
TOTAL DRAINAGE AREA OF LAKE = 434601.8
SUM OF SUB-DKAINAGE AREAS = 434601.7
MEAN MONTHLY FLO^S AND DAILY FLOwS(CMS)
TRIBUTARY MONTH YEAR MEAN FLOW DAY
3201A1
FLOW DAY
3201A2
SUMMARY
TOTAL FLOW IN
TOTAL FLOW OUT
3774.63
FLOW DAY
FLOW
11
12
12
1
1
?
3
3
4
4
5
6
6
7
1
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
74
74
74
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
74
74
75
75
75
75
75
75
75
75
75
75
239.787
195.811
195.811
237.324
237.324
314.600
344.899
344.899
414.559
0.0
445.990
383.976
383.976
382.277
382.277
370.667
317.715
252.813
368.119
283.168
379.446
311 .485
277.505
254.852
43B.911
481 .386
580.495
495.545
481 .386
0.0
16
13
21
18
2«
17
2«
23
23
17
17
30
18
31
20
2fi
13
1«
17
17
147.248
152.345
151.212
157.442
273.824
353.960
410.594
438.911
487.050
359.624
455.901
399.267
424.753
424.753
441.743
227.951
396.436
263.347
413.426
331.307
16
13
20
18
28
17
28
23
29
17
17
30
)8
31
20
28
103.640
147.248
108.170
158.574
275.240
393.604
552.178
665.446
64b.456
555.010
594.654
509.703
424.753
368.119
339.802
192.555
-------
APPENDIX C
PHYSICAL AND CHEMICAL DATA
-------
RETRIEVAL uATE 77/01/22
NATL EUTROPHICAflON SURVEY
EPA-LAS VEGAS
320131
36 06 51.0 114 47 27.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES 0400100?
0064 FEET DEPTH CLASS 00
OATF
FROM
TO
75/02/24
75/06/11
75/1 1/20
00010
TIME OEPTH WATER
OF TtMP
DAY FEET
10
10
10
10
10
10
13
13
13
13
13
13
14
14
14
14
14
14
30
30
30
30
30
30
00
00
00
00
00
on
15
15
15
15
15
15
000^
0005
0015
0030
0055
ooan
0000
0005
0015
0030
0060
008*
OOOn
0005
0015
OO:K
0000
0086
CENT
7.9
8.4
8.4
8.4
8.4
8.3
23.2
22.9
22.8
20.1
14.4
12.7
15.7
15.7
15.7
15.*,
15. ft
15.4
00300 00077 00094
00 ThAwsP CNDUCTVY
t;Eccni FIELD
MG/L INCHES MICPOMHO
9.6
7.2
10.0
10.2
9.8
9.6
9.0
7.*
9.6
9.8
7.6
7.0
8.6
8.4
8.2
3.4
R.6J
8.2
190 1154
1041
1066
1574
1266
1198
190 1266
1253
1246
1171
1107
1070
84 834
837
R40
S46
849
H40
00400 00410
PH T ALK
CAC03
SH
8.20
8.20
8.20
8.20
8.20
R. 20
8.25
fi.50
8.60
8.50
8.20
8.15
8.35
8.35
8.30
a. 30
8.30
8.30
MG/L
135
133
134
134
135
133
130
131
129
129
140
140
125
12ft
128
129
133
135
00610 00625 00630 00671
NH3-N TOT KJEL N02&N03 PHOS-OIS
TOTAL N N-TOTAL ORTHO
MG/L
0.060
O.OPO
0.030
0.030
0.030
O.OPQ
0.150
0.020
0.030
0.030
0.070
0.070
0.040
0.040
0.040
0.040
0.050
0.040
MG/L
1.700
0.400
0.300
0.300
0.300
0.400
3.300
0.500
0.400
0. 300
O.*00
0.400
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
MG/L
0.350
O.?40
0.340
0.360
0.360
0.340
0.100
O.OBO
O.Q90
0.170
0.360
0.370
0.180
0.160
0.160
0.160
0.160
0.160
MG/L P
0.026
0.019
0.019
0.020
0.022
0.020
0.008
0.003
0.002
0.007
0.071
0.075
0.014
0.014
0.015
0.014
0.014
0.014
00665
DATE TIME DEPTH PHOS-TOT
FROM OF
TO OAY FEET MG/L P
75/08/24
75/06/1 1
75/11/20
10
10
10
10
10
10
13
13
13
13
13
13
14
14
14
14
14
14
30
30
3n
30
30
30
00
00
00
00
no
00
15
15
15
15
15
15
ooon
0005
0015
00 JO
0055
0080
0000
0005
0015
0030
0060
0086
0000
OOOb
1014
0030
006"
0086
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.057
.044
.04T
.043
.039
.043
.029
.01?
.014
.Iil8
.07?
.075
.037
.037
.03*
.037
.03?
.035
32217
CHLRPHYL
A
U6/L
1.9
00031
INCDT LT
.3.0
PFKCFNT
1.0
K VALUE KNOWN TO BE LESS
THAN INDICATED
J VALUE KNOWN TO BE INDICATED
-------
STO«ET RETRIEVAL DATE 77/01/22
MATL EUTROPhlCATIO"' SURVEY
EPA-LAS >/tGAS
/TYDA/AM8NT/LAKE
320132
36 03 47.0 114 48 50.0 3
LAKE MEAD
32003 NEVADA
11EPALES
0999 FEET
04001002
OEHTH CLASS 00
00010
DATE TIME DEPTH WATER
FPO*i OF TEMP
TO DAV FEET CENT
75/02/24 11
11
11
11
11
11
11
11
11
75/0(3/11 13
13
13
13
13
13
13
75/11/20 14
14
14
14
14
14
14
)4
75/l?/ll 10
in
10
10
10
10
10
55
55
55
55
55
55
55
55
55
35
35
35
35
35
35
35
40
40
40
40
40
40
40
40
05
05
05
05
05
05
05
0000
0005
0015
0030
0055
0085
0105
0135
0165
0000
0005
0015
003"
0060
0100
0156
00 DC
0005
0015
0045
0090
0130
Ol4f)
017)
0000 -
0005
0015
0031
OObO
010P
0215
8.6
8.5
8.5
8.4
8.5
8.4
8.4
8.5
8.5
24.?
23.0
22.3
21.5
14.6
12.1
10.7
16. ]
16.1
16.1
16.0
16.0
15.9
13.6
12.^
14.1
!•*.!
13. ^
14.0
13.9
11.6
00300 00077 000t><»
DO TKANS0 CNDUCTVY
=:ECCHI FIELD
MG/L INCHES MIC«OMhO
9.2
9.0
9.0
9.0
9.n
9.0
9.0
9.0
9.0
9.0
9.2
9.0
9.0
8.0
8.6
8.0
7.8
7.8
7.4
7.8
7.8
7.?
4.6
5.0
9.2
8.«
8.4
8.6
8.0
9.0
6.4
196 1122
1088
1132
1 153
12(13
1075
1197
1197
1102
1=50 1260
1250
1231
1210
1045
999
965
180 845
860
653
857
H51
851
810
775
206 791
79H
79d
799
818
h!8
790
00400 00410
PH T ALK
CAC03
SIJ
8.20
8.10
8.10
8.10
8.10
8.10
8.10
8.10
8.10
8.50
ft. 50
8.50
8.30
8.20
8.10
8.15
H.20
8.20
8.20
8.20
8.20
8.00
7.80
7.90
•8.00
7.92
P. 00
7.99
7.99
7.98
7.74
Mfi/L
137
135
135
136
136
136
135
136
135
128
128
127
130
139
137
128
137
131
131
130
130
125
145
136
125
126
126
1^5
12*
125
'140
00610 00625 00630 00671
NH3-N TOT KJEL N028,Nf13 PHOS-OIS
TOTAL N N-TOTAL ORTHO
MG/L
0.030
0.020K
0.020
0.030
0.020
0.020
0.020
0.020
0.0?0
0.030
0.020
0.030
0.030
0.060
0.030
0.030
0.020
0.030
0.030
0.030
0.030
0.020K
O.OPOK
0.020
0.040
0.030
0.040
0.050
0.040
0.050
0.030
MG/L
0.500
0.300
0.300
0.400
0.300
0.400
0.300
0.300
0.400
0.700
0.500
0.400
0.500
0.400
0.400
0.400
0.200K
0.200
0.200K
0.200K
0.200K
0.200K
0.300
0.300
0.200K
0.200"
0.200K
0.200K
0.200K
0.200K
0.200K
MG/L
0.380
0.370
0.370
0.370
0.370
0.370
0.360
0.360
0.360
0.120
0.120
0.130
0.140
O.?50
0.320
0.120
0.?QO~
O.?10
O.?10
O.?10
o.?oo
O.?20
0.420
O.?30
0 . ? 5 0
O.?60
O.?60
O.?60
O.?60
O.?60
0.430
MG/L P
0.020
0.019
0.017
0.02fc
0.022
0.020
0.018
0.017
0.01P
0.006
0.003
0.004
0.003
0.003
0.006
0.003
0.006
0.007
0.006
0.005
0.006
0.007
0.007
0.007
0.006
0.006
0.006
O.OOh
0.006
0.007
0.00^
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STO*ET RETRIEVAL OATE 77/01/22
NATL EUTROHnICATIO<" SURVEY
tPA-LAS VEGAS
/TYPA/AMBNT/LAKE
320132
36 03 47.0 114
LAKE MEAD
32003 NEVADA
11EPALES
0999 FEET
50.0 3
110191
04001002
OEH-TH CLASS oo
UATE
TO
75/02/24
75/06/1 1
75/11/20
75/12/11
00665 32217 00031
TIME DEPTH PHOS-TOT CHLRPHYL IwCDT LT
OF A <-
-------
RETRIEVAL DATE 77/01/2?
NATL RUTPOPnlCATION. S>j>JVtY
FPA-LAS VEGAS
320133
36 01 ?5.0 114 43 40.0 3
LAKE MEAD
32003 .NEVADA
/TYPA/AM.B'IT/LAKE
00010
DATE
rc
75/02/24
75/06/1 1
75/1 1/20
TI"F DEPTH t
OF
DAY FF.tT
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
IS
15
15
15
15
15
15
15
15
30
30
30
30
30
30
30
30
05
05
05
05
05
05
OS
05
IS
15
15
15
15
15
15
15
IS
0000
0005
0015
0030
0060
0090
0125
0160
0000
0005
0015
003P
0060
0100
0150
0200
0000
OOOS
0030
0054
0085
0120
0150
0190
0230
IATER
Tt«P
CENT
9.0
8.9
d.fl
8.7
8.fc
a.5
8.=,
rt.S
23.?
22. -i
22.1
21. s
14.7
11.7
10.7
10.?
16.?
16.?
16.?
lt>.?
16.2
15.9
13.3
12.3
12.3
0030U
DO
9.0
10.0
9.6
9.11
9.0
9. a
9.0
9.2
9.0
9.2
9.0
8.6
8.0
8.0
8.*
B.4
7.2
7.2
7.2
7.2
7.0
6.0
5.0
6.0
7.0
00077 00094
CNOUCTVY
FIELD
INCHES MICROMHO
184
28M
144
1090
1075
1124
1101
1 106
1110
1262
1247
1231
1213
1045
9H8
965
955
rt40
850
850
840
836
«02
768
727
11EPALES
0999
00400
PH
SO
8.20
8.20
8.20
8.20
8.20
".10
H.10
8.10
ft. 55
ft. 50
*.Su
8.30
8.20
B.10
H.10
R.50
H.10
H.10
a. 10
fl.10
fl.10
e.oo
7.60
7.95
H.OO
FEET 01
00410
r ALK
CAC03
MG/L
136
138
137
137
137
13H
138
138
133
131
1 Jl
132
139
139
139
140
131
132
129
128
136
13b
141
141
140
DEF'TH
0400
H CLASS
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.0?OK
0.0?OK
0.020
0.0?0
0.020
O.OPO
o.oso
0.030 =
0.030'
0.040
0.080
0.030
0.030
0.030
o.o?6
0.0?0
0.020
0.020
0.020
0.020
0.020
0.0?0
0.020
1002
00
00625
TOT KJEL
N
MG/L
0.400
0.300
0.400
0.400
0.300
0.300
0.300
0.300
0.900
0.500
n.40o
o.soo
0.400
0.400
0.400
0.300
0.400
0.200
0.200
o.?oo
0.200
o.?oo
0.300
0.300
0.200
00610
N02S.N03
N-TOTAL
MG/L
0.360
O.TSO
0.360
0.3hO
0.3*0
0.360
o.?*.o
0.360
0.1SO
0.140
0.140
o.mo
O.?40
0.360
0.390
0.410
O.??0
O.??0
0.220
O.??0
0.370
0.420
0.420
0.420
0.420
00671
PHOS-OIS
OPTnO
MG/L P
0.017
0.016
0.017
0.017
0.017
0.016
0.017
0.017
0.003
0.00«
0.003
0.008
0.007
0.013
0.020
0.022
0.002K
0.002K
0.002K
0.006
0.005
0.007
0.00*
0.013
0.01 1
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/8?
NATL EUTROPHICATIOM SURVEY
EPA-LAS VEGAS
320133
36 01 25.0 11*
LAKE MEAD
32003 NEv/AOA
43 40.0 3
/TYPA/AMBNT/LAKE
11EPALES
0999 FEET
DEPTH
04001002
CLASS 00
00665
DATE TIME DEPTH PHOS-TOT
FROM OF
TO DAY FEET MG/L p
75/02/24
75/06/11
75/11/20
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
15
15
15
15
15
15
15
15
15
30
30
30
30
30
30
30
30
05
05
05
05
05
05
05
05
15
Ib
15
15
15
15
15
15
15
0000
0005
0015
003P
0060
0090
0125
0160
OOOn
0005
0015
0030
0060
0100
0150
0200
0000
0005
0030
0054
0085
0120
0150
0190
0230
0.041
0.041
0.041
0.040
0.03P
0.036
0.036
0.040
0.011
0.010
0.011
0.01?
0.013
0.012
0.019
0.020
0.016
0.015
0.017
0.014
0.015
0.012
0.011
0.014
n.ou
32217
CHLRPHYL
A
UG/L
1.4
00031
IMCDT LT
PFMNING
PERCENT
1.0
1.9
3.7
-------
STORE! RETRIEVAL DATE 77/01/33
NATL EUTQOPHICATIC^ SURVEY
EPA-LAS VEGAS
320134
36 07 45.0 114 42 25.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
11EPALES 04001002
0154 FEET DEPTH CLASS 00
00665
DATE TIME DEPTH PHOS-TOT
F40M OF
TO DAY FEET MG/L P
75/02/24
75/06/11
75/11/21
15
15
15
15
15
15
15
15
14
14
14
14
14
14
14
14
13
13
13
13
13
13
13
30 OOOfl
30 0005
30 001S
30 0030
30 0060
30 0090
30 0120
30 0150
45 0000
45 0005
45 0015
45 0030
45 0060
45 0100
45 015"
45 0200
15 0000
15 0005
15 0025
15 0045
15 0080
15 0110
15 0150
0.037
0.034
0.03?
0.035
0.033
0.031
0.035
0.036
0.012
0.010
O.OOQ
0.009
O.OOP
0.009
0.016
0.01^
0.012
0 . 0 1 3
0.01?
0.013
0.013
0.01?
0.009
32217
CHLrtPHYL
A
UG/L
2.4
00031
INCDT LT
P.FMNING
PFRCENT
1.0
1.6
4.3
-------
RETRIEVAL uATE 77/01/22
NATL EUTWOPhlCATIO'
EPA-LOS VERAS
320134
36 07 45.0 114 42 25.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMHNiT/LAKF
DATE TIME DEPTH
FROM OF
TO OAV FEFT
75/02/24
lltPALES
0154 FEET
OEPTH
0400100?
CLASS 00
00010
4ATEQ
TtMP
CEMT
75/06/11
75/11/21
00300
00
MG/L
15
15
15
15
15
15
15
15
14
14
14
14
14
14
14
14
13
13
13
13
13
13
13
30
30
30
30
30
30
30
30
45
45
45
45
45
45
45
45
15
15
15
15
15
15
15
0000
OOQ5
001s.
0030
0060
0090
012ii
0150
0000
0 0 0 5
0015
0030
0060
0100
0150
0200
0000
0005
002^>
0045
0080
0110
0150
6
8
8
rt
8
rt
8
8
22
?2
20
20
15
12
in
9
16
16
16
16
16
16
13
.
•
•
9
•
•
•
.
•
•
•
•
•
.
•
•
•
•
•
*
•
•
•
8
5
5
e
5
5
5
•}
?
2
7
0
8
1
u
8
?
?
2
?
1
1
3
10
9
9
9
9
9
9
9
10
8
9
8
8
8
^
7
7
7
7
7
7
5
.0
.4
.4
.4
.0
.2
.4
.4
.0
.8
.0
.8
.6
.4
. ()
.e>
.8
.4
.4
.4
.0
.2
00077
THANSP
^ECCMI
INCHES
2?8
2?8
240
00094
CNOUCTVY
FIELD
MICKOMHO
1103
1100
1100
1130
1129
1106
1116
1108
1229
1227
1187
1168
1052
991
946
92V
807
?94
820
819
«42
811
767
094
CTVY
D
OMHO
1103
1100
1100
1130
1129
1106
1116
1108
1229
1227
1187
1168
1052
991
946
92V
807
794
820
819
«42
811
767
00400
PH
Sll
8.30
8.20
8.20
8.2X)
8.20
3.20
8.20
8.20
8.70
8.60
8.60
8.40
8.40
8.20
a. 10
8.10
8.30
8.20
8.20
8.20
8.20
B.10
7.90
00410
T ALK
CAC03
MG/L
139
140
140
135
135
135
137
136
143
138
140
143
145
140
143
142
141
132
132
131
129
125
139
00610
NH3-N
TOTAL
MG/L
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.0?0
0.030
0.030
0.030
0.040
0.050
0.030
0.030
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00625
TOT KJEL
-N
MG/L
0.300
0.200
0.300
0.300
0.300
0.300
0.300
0.300
0.600
0 . "•* 0 0
0.300
0.300
0.300
0.300
0.200
0.200
0.20 OK
0.200K
0.200K
0.200K
0.200K
0.^00*.
0.200K
006">0
N02S.N03
N-TOTAL
MG/L
0.340
0.3*0
0.350
0.370
0.360
0.360
0.350
0.340
o.?oo
0.170
O.?00
O.?20
0.280
0.320
0.420
0.420
0.300
O.?20
0.220
0.220
O.?10
O.?10
0.420
00671
PHOS-OIS
0»THO
MG/L P
0.011
0.012
0.013
0.014
0.012
0.012
0.018
0.013
0.004
n.ooi
0.002
0.002
0.00?
0.003
0.013
0.015
0.002K
0.002K
0.002K
0.002K
0.004
0.002
0.003
K VALUE KNOVIN TO BE LESS
THAN INDICATED
-------
STOrfET RETRIEVAL
MftTL EUTPOJPHI
EPA-LAS VEGAS
SURVEY
DATE
FRO"
10
75/02/25
75/06/12
75/12/01
OF
DAY
14
14
14
14
14
14
14
10
10
10
10
10
10
09
09
09
09
09
09
35
35
35
35
35
35
35
05
05
05
05
05
05
00
00
00
00
on
00
DEPT*
FEET
0000
0022
0040
0060
0085
01 10
0144
0000
0005
0030
0060
0100
0144
OOOn
0005
002^
005n
0100
015n
00010
WATER
TEMP
CENT
3.1
l'.7
7. ft
7.4
7.3
7.3
7.1
21.3
21.2
19.2
14.2
11.7
10.4
15.7
15.7
15.7
15.7
15.5
15.4
00661
DATt
f 3 0 M
TO
75/02/25
7b/0b/12
75/12/01
TIME
OF
DAY
14
14
14
14
14
14
14
10
10
10
10
10
10
09
09
09
09
09
09
35
35
35
35
35
35
35
05
05
05
05
O1-
05
00
00
On
on
on
00
DEPTH
FEET
0000
0022
0040
0060
0085
01 10
Olf 4
OOOn
0005
003"
0060
01 un
0144
OOOn
000^
002 =
00 = 0
0100
0150
PHOS-TOT
MG/L P
0
0
0
0
0
o
0
0
0
0
0
0
0
0
f)
0
0
0
0
.027
.020
.018
.020
.020
.n,?p
.0??
.00'-
.005
.006
.005
.OOv
.023
.007
.OOf,
.00«:
.f'0?>
.00 -<
.01-5
00300
00
MG/L
10
10
10
10
10
10
10
8
8
8
9
8
M
H
8
y
B
H
H
3221
.6
.8
.6
.4
.0
.2
.4
.6
.b
.6
.0
.0
.4
.0
.6
.6
.2
.4
.6
7
CHLRPHYL
A
UG/L
2
0
I
.1
.7
.0
00077
INCHES
168
336
120
00031
INCDT LT
PFMNING
"FKCE'NT
1.0
00094
CNOUCTVY
FIELD
1045
1038
1019
1043
1009
104H
1060
1216
1211
1136
1020
951
920
861
861
862
H6<»
862
869
32013b
36 23 00.0 114 22 36.d 3
LAKE MEAD
32003 NEVADA
110191
11EPALES
0146
00400
PH
SU
8.30
8.30
8.30
8.30
8.30
8.30
8.30
8.55
8.55
8.40
8.20
8.20
8.30
R.OO
8.00
8.00
8.00
8.00
8.00
FEET 0
00410
T ALK
CAC03
MG/L
143
143
142
142
143
142
143
141
144
143
141
144
144
131
132
133
133
133
131
04001002
H CLASS
00610
NH3-N
TOTAL
MG/L
0.020
0.020K
0.0?OK
0.020K
0.020K
0.020K
0.030
0.060
0.040
0.040
0.040
0.040
0.040
0.020K
0.020K
0.020K
0.020K
O.OPOK
0.020K
00
00625
TOT KJEL
N
MG/L
0.600
0.300
0.300
0.300
0. 300
0.300
0.300
0.400
0.300
0.300
0.300
0.400
0.400
0.200
0.200K
0.200
0.200
0.200
0.200*
00630
N025.N03
N-TOTAL
MG/L
0.370
0.3*0
o.?6o
0.360
0.350
0.3SO
0.360
0.310
O.?90
0.310
0.350
0.400
0.400
O.?70
o.?*so
0.210
0.260
O.P60
0.240
00671
PHOS-DIS
OMTHO
MG/L P
0.004
0.002
0.003
0.003
0.002K
0.002K
0.003
0.005
0.002
0.002
0.002
0.002
0.003
0.002
0.002K
0.002K
0.002K
0.002K
0.002
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL UATF. 77/01/22
MAIL F.UTROPHICATIO'V
EPA-LAS V/t(3AS
320135
36 2a 20.0 11*
LAtvt MEAD
3P003 NEVADA
20 37.0 3
110 191
/TYPA/AM8NT/LAKE
11EPALES
0045 FEET
DEPTH
04001002
CLASS 00
DATE
FPO">
TO
75/02/25
75/06/12
75/11/21
oouin
TIME DEPTH *ATE4
OF T6.MP
DAY FEET
08
08
08
08
08
0«
10
10
10
10
10
15
IS
15
15
15
45
45
45
45
45
45
30
30
30
30
30
10
10
10
in
in
0001
ooos
0015
002?
oo3n
0040
0000
0005
0020
0040
0054
0000
0005
0025
0041
0045
CENT
7.5
7.6
7.3
7.?
?.?
7.1
20.9
20. f,
19.7
Ib.Cy
15.6
14. f
14.7
14.6
14.6
14.6
00300 00077 00094
DO TRANSP CNDUCTVY
SECCHI FIELD
MG/L INCHES MIC^OMHO
10.6
10.?
10. 6
10.6
10.6
10.4
9.2
9.0
8.8
8.2
8.4
10.4
8.6
8.4
8.4
8.6
108 1074
1036
1057
1045
1027
1055
276 1215
1193
1177
1111
1070
120 782
HO 3
800
808
795
00400 004-10
PH T ALK
CAC03
SIJ
8.10
8.15
8.20
8.30
8.30
8.30
8.45
B.45
8.45
».25
8.25
8.30
8.30
8.30
8.30
8.30
MG/L
143
142
142
142
142
141
144
144
141
145
145
140
141
142
Ifl
143
00610 00625 00630 00671
NH3-N TOT KJEL N02&N03 PHOS-DIS
TOTAL N N-TOTAL ORTflO
MG/L
0.0?OK
0.020K
0.020K
O.OPOK
0.020
0.020K
0.040
0.040
0.030
0.040
0.040
0.020K
0.0?OK
0.020K
0.020K
0.020K
MG/L
o.-*oo
0.300
0.4QO
0.400
0.300
0.300
0.600
0.300
0.200
0.300
0.300
0.200K
0.200K
0.200*
0.200K
0.200K
MR/L
0.350
0.340
0.350
0.340
0.350
0.340
O.?ft6
0.?RO
0.280
0.300
0.320
O.?30
0.220
0.220
O.?20
O.?20
MG/L P
0.005
0.003
0.003
0.002
0.003
0.003
0.002K
0.002K
0.002K
0.002K
0.002K
0.002
0.002K
0.002K
0.002K
0.002K
00665
DATE TIME DEPTH PnOS-TOT
FRO'1 OF
TO DAY FEET MG/L P
75/02/25
75/06/12
75/11/21
08
08
08
09
r>6
08.
10
10
10
10
10
15
15
15
15
15
45
45
45
45
45
45
30
30
30
30
30
10
10
10
10
10
0000
0005
0015
0022
0030
0040
0000
0005
0020
0040
0034
0000
ooos
0025
0041
0045
0
0
0
0
0
0
0
0
0
(I
f!
II
0
0
0
0
.025
.023
.021
.021
.020
.022
.00«
.ons
.008
.on*
.Of".
.00^
,00«
.00*3
.008
.014
32217
CHLRPHYL
A
IIG/L
1.0
1 .
00031
IMCDT LT
1.0
K VALUE KNOWN TO BE
LESS THAN INDICATED
-------
RETRIEVAL OATE 77/II1/??
r- ATL
F.KA-LftS VEGAS
/TYPA/AMBNT/LAKE
320137
36 17 37.0 114 23 13.n 3
LAKE MEAO
32003 NEVADA
110191
HEPALES
0240 FEET
DEPTH
04001002
CLASS 00
00665
DuTE TIN-E DEPTH PMOS-TOT
F=0* Of
10 OAY FEET M6/L P
75/02/26
75/06/12
75/12/01
08
08
08
08
08
OH
08
08
09
09
09
09
09
09
09
09
09
09
09
09
09
09
45
4.5
45
45
45
45
45
45
35
35
35
35
35
35
35
45
4S
45
45
45
45
45
0000
0005
001S
0025
0050
0100
0150
OldO
0000
0005
0030
0060
oion
0150
0200
0000
0005
003S
0070
0100
0150
0200
0
0
U
0
n
0
0
0
0
0
0
0
0
1)
0
0
0
U
0
0
0
0
.027
.020
.019
.023
.020
.0?5
.020
.020
.DOS
.00=;
.00^
.005
.005
.OOH
.OOR
.006
.004
.006
.006
.00^
.009
.00«
32217
CHLftPHYL
A
UG/L
0.5
00031
IMCDT LT
RFMMNG
PFhCEiNT
0.6
0.9
-------
STORE! RETRIEVAL DATE 77/01/32
NATL EOTROPHICATIOM SURVEY
EPA-LAS VFGAS
/TYPA/AMBNT/LAKE
DATE
FROM
TO
75/02/26
75/06/12
75/12/01
00010
TIME DEPTH WATER
OF TEMP
DAY FEET
08
OH
08
08
08
08
08
08
09
09
09
09
09
09
09
09
09
09
09
09
09
09
45
45
45
45
45
45
45
45
35
35
35
35
35
35
35
45
45
45
45
45
45
45
0000
0005
0015
0025
0050
0100
0150
0180
0000
0005
0030
0060
0100
0150
0200
0000
0005
0035
0070
0100
0150
0200
CENT
10
10
10
10
10
10
10
10
21
21
20
13
11
10
10
15
15
15
15
15
15
15
.7
.8
.4
.3
.?
.1
.1
.1
. 7
.5
.5
.9
,P
.7
.1
.8
.«
.fl
.8
.8
.7
.7
00300
DO
MG/L
10.2
10.0
10.0
10.n
10.2
10.0
10.4
10.?
8.8
8.8
8.6
8.6
8.6
8.6
8.6
8.2
8.*
8.2
8.6
8.6
7.2
6.8
00077
THANSP
<=ECCHI
INCHES
216
40a
180
00094
CNOUCTVY
FIELD
MICP.OMHO
761
758
757
756
757
758
759
760
1213
1203
1178
991
953
921
914
838
833
843
842
838
839
820
330137
36 17 37.0 114 33 18.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES
0240 FEET
DEPTH
04001002
CLASS 00
094
CTVY
D
OMHO
761
758
757
756
757
758
759
760
1213
1203
1178
991
953
921
914
838
833
843
842
838
839
820
00400
PH
su
8.20
8.25
8.20
8.20
8.30
8.30
8.30
8.30
e.eo
8.60
8.60
8.25
8.20
3.20
8.25
8.00
7.90
7.90
7.80
7.70
7.70
7.60
00410
T ALK
CAC03
MG/L
144
144
144
144
145
146
146
145
142
141
143
142
143
142
143
133
133
131
131
131
135
144
00610
NH3-N
TOTAL
MG/L
0.040
0.0?OK
0.0?OK
0.020K
0.020K
0.020K
0.020K
0.020K
0.040
0.030
0.040
0.040
0.030
0.030
0.040
0.020K
O.OPOK
0.020K
0.020K
0.020K
0.020K
0.030
00625
TOT KJEL
N
MG/L
1.100
0.400
0.300
0.300
0.400
0.500
0.400
0.300
0.400
0.300
0.200
0.300
0.300
0.300
0.400
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200
00630
N028.N03
N-TOTAL
MG/L
0.380
0.370
0.370
0.380
0.360
0.360
0.360
0.360
0.300
O.?90
0.290
0.360
0.390
0.4QO
0.400
0.320
0.320
0.320
0.320
0.320
0.400
0.^00
00671
PHOS-DIS
ORTHO
MG/L P
0.012
0.012
0.012
0.013
0.013
0.017
0.014
0.014
0.002K
0.002K
0.004
0.002
0.002
0.003
0.005
0.019
0.002
0.002K
0.002K
0.002
0.002
0.004
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/2?
NATL EUTQOPHICATION SURVEY
EPA-LAS VEGAS
320140
36 08 30.0 114 35 50.0 3
32003 NEVADA
11EPALES 04001002
0999 FEET DEPTH CLASS 00
DATE TI^iE DEPTH ,
FROM OF
TO DAY FEET
75/02/25 14
14
14
14
14
14
14
14
14
14
14
75/U6/11 15
15
15
15
15
15
15
75/11/21 13
13
13
13
13
13
13
13
75/12/01 10
10
10
10
10
10
10
25
25
25
25
25
25
25
25
25
25
25
20
20
20
20
20
20
20
45
45
45
45
45
45
45
45
45
<*5
fc5
45
45
45
45
0000
0005
0015
0030
0045
0060
0090
0120
0150
0180
0200
oouo
0005
0015
0050
0100
0150
0200
0000
0005
0025
005"
0 lO^
0140
0190
0230
0000
0005
002(1
00«»0
0090
0145
0200
00010
(ATEri
Tt^P
CE^T
11.8
11.?
11.1
11.0
11. n
11.0
11.0
10. P
10.8
10.6
10.7
21.1
20.8
20.2
15.6
12.?
10.5
10.0
16.1
16.)
lfi.1
16.1
15. H
13.7
ll.fi
11.1
16.7
16.7
16. 1
16. h
16.-
16. T
14. S
00300 00077 00094
DO THA"ISP CNDUCTVY
cECCHl FIELD
MG/L INCHES MICROMHO
11.0
11.1
10.3
10.3
10.3
10.4
10.5
10.3
10.2
10.2
9.5
H.6
9.0
9.0
9.0
9.0
6.8
8.9
7.8
7.6
7.4
7.4
7.0
5.8
7.0
6.6
8.8
7.6
7.8
7.4
7.2
7.0
7.2
300 806
795
795
794
794
771
791
771
768
764
766
444 11«0
1170
1155
1031
967
923
913
204 79fc
792
795
815
803
785
708
720
600 871
870
87U
870
871
862
824
00400 00410
PH T ALK
CAC03
SU MG/L
8.20
8.20
8.20
8.20
8.20
8.20
8.20
8.20
8.20
8.20
8.10
«.55
8.55
8.55
6.25
«.?0
8.20
8.60
8.20
8.20
8.25
H.20
8.10
7.95
8.00
8.10
P. 00
8.00
e.oo
7.90
7.90
7.80
7.80
148
147
147
146
136
138
138
141
140
140
141
148
145
147
147
145
145
146
132
136
134
13h
139
144
143
144
139
138
136
138
131
131
135
00610 0062S 00630 00671
NH3-N TOT KJEL N02&N03 PHOS-DIS
TOTAL Ni N-TOTAL ORTHO
MG/L MG/L MG/L MG/L P
0.030
0.020K
0.020K
0.020
0.020
0.0?0
0.020
0.020
0.030
0.0?0
0.020
0.040
0.030
0.030
0.030
0.030
0.030
0.280
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020
0.030
0.020
0.030
0.020K
0.020K
0.020K
0.300
0.300
0.200
0.200K
0.300
0.300
0.300
0.200
0.200
0.200
0.200
0.600
0.200
0.200
0.200*
O.?00;\
0.200*
0.300
0.200K
0.200*
0.200K
0.200K
0.200*
0.200K
0.200*
0.200*
0.200
0.200
0.200
0.300
0.200
0.300
0.200K
0.370
0.360
0.370
0.370
0.360
0.350
0.350
0.370
0.370
0.370
0.380
0.310
0.300
0.310
0.330
0.390
0.4QO
0.390
0.300
0.300
0.300
O.TOO
0.350
0.440
0.420
0.420
0.320
0.340
0.330
0.340
0.340
0.390
0.430
0.01?
0.008
0.006
o.ooe
0.007
0.007
o.ooe
0.006
0.015
0.005
0.006
0.003
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002*
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.00?
0.00?
0.002K
0.002K
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL U^TE 77/01/2?
NATL EUTWOPHICATIO'-'
tPA-LAS VEGAS
/TYPA/AM6NT/LAKE
32013=)
36 07 52.0 114 53 05.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES
0015 FEET
DEPTH
04001002
CLASS 00
DATE
FRO"-'
TO
75/02/24
75/11/20
TI«E DEPTH
OF
DAY FEET
13 20 0000
13 50 0000
13 50 0005
13 50 0015
13 50 0025
13 5n 0041
00010
wATE*
T£M^
CENT
10.9
15.4
15.4
15.3
15.1
14.5
00300
00
MG/L
13.9
S.O
8.6
B.4
8.4
00077
TKAIMSP
<;ECCHI
INCHES
65
000-^4
CNOUCTVY
FIELD
MIC«OMHO
866
82S»
618
927
840
844
Of>400
PH
su
8.40
8.40
8.40
8.35
8.35
8.40
00410
T ALK
CAC03
MG/L
138
117
126
129
130
131
00610
NH3-N
TOTAL
MG/L
0.0?0
0.030
0.030
0.030
0.030
0.030
00625
TOT KJEL
N
MG/L
0.300
O.
-------
STOf-ET P£T^IEv/AL UATE 77/01/22
NATL EUTROPhlCATIO'-
EPA-LflS VEGAS
DATE
TO
75/02/26
75/06/1?
75/12/0?
00010
TIME DEPTH KfATtR
OF TEMP
DAf FEET
09
09
09
09
09
09
09
09
09
09
09
tl9
09
09
09
10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
10
10
10
10
10
10
10
00
00
00
00
00
00
00
00
00
0000
0005
001^
0025
0050
0100
0150
0200
OOOP
00(15
0030
0060
0100
OlbO
0200
0 0 U 0
OOO1^
0015
0040
007->
0110
0150
01*0
o??o
CENT
10.
10.
10.
10.
10.
10.
10.
10.
20.
20.
IB.
16.
12.
4.
s*.
16.
16.
16.
16.
16.
16.
Ib.
14.
13.
9
a
8
«,
H
4
4
4
s
7
4
1
I
9
&
n
n
n
n
n
0
0
4
•J
00300
00
MG/L
10
9
<-i
9
10
9
10
8
9
9
8
8
9
9
8
8
H
a
8
7
rt
b
/
.
.
.
.
9
»
.
a
.
.
.
.
e
.
.
.
.
.
.
o
.
.
.
0
8
6
6
2
P.
2
8
0
0
d
8
?
0
?
6
b
&
A
6
4
2
?
00077
TKAi-JSP C
^Eccrii FIELD
INCHES M
312
444
600
32013b
36 11 50.0 114 25 06.0 3
LAKE MEAD
32003 NEVADA
110191
HEPALES 04001002
0310 FEET DEPTH CLASS 00
094
CTVY
D
OMHO
761
7^9
7b4
756
755
752
752
752
1 164
115b
1103
103*
957
910
905
838
833
834
f 40
637
839
838
810
802
00400
UN
SO
8.30
8.30
8.30
8.30
8.30
8.30
8.30
8.30
8.60
^.60
8.60
A. 30
«. 25
8.20
8.25
8.50
P. 50
8.60
8.50
8.bO
8.50
8. SO
8.20
8.20
00410
T ALK
CAC03
MG/L
142
143
141
142
141
140
140
138
144
143
144
142
143
140
140
137
140
140
139
139
136
13b
143
138
00610
NH3-N
TOTAL
MG/L
0.030
0.0?OK
0.020
0.020
0.030
0.0?0
0.030
0.020
0.040
0.030
0.030
0.030
0.040
0.030
0,030
0.020K
0.020K
0.020K
O.OPOK
0.020K
0.0?OK
0.020K
O.OPOK
0.020K
00625
TOT KJEL
N
MG/L
1.800
0.800
0.800
0.300
0. 300
0.300
0.300
0.300
0.400
0.300
0.300
0.400
0.300
0.400
0.300
0.200K
0.200
0.200
0.200K
0.200K
0.200*
0.?OOK
0.200K
0.200K
00630
N02&N03
N-TOTAL
MG/L
0.380
0.380
0.380
0.380
0.380
0.380
0.380
0.370
0.320
0.320
0.330
0.320
0.380
0.400
0.4QO
0.330
0.330
0.330
0.330
0.330
0.330
0.330
0.420
0.420
00671
PHOS-OIS
OHThO
MG/L P
0.012
0.010
0.012
0.012
0.01?
0.010
O.Olb
0.016
0.002K
0.002K
0.002K
0.002K
0.002K
0.003
0.003
0.00?K
0.003
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOh>ET RETRIEVAL UATt 77/01/22
NATL
EPA-LAS VEGAS
/TYPA/AM8MT/LAKE
36 11 50.0 114 25 06.0 3
LAKE MEAD
32003 NEVADA
11EPALES 04001002
0310 FEET DEPTH CLASS 00
00665
DATE TIME DEPTH PHOS-TOT
F»o< Oi-
TO DAY FEET MG/L P
75/02/26
75/06/12
75/12/0?
09
09
09
09
09
09
°\
os|
09''
09
09
09
09
09
09
10
1 0
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
10
10
10
10
10
10
10
00
00
00
00
00
00
00
00
on
OOQO
0005
0015
0025
0050
0100
0150
0200
0000
oooc
0030
0060
0100
0150
0200
0000
000^
0015
0040
0075
0110
0150
0190
0220
0.
0.
0.
0.
u.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
o.
I).
0.
0.
0.
020
01*
020
020
020
0?0
020
023
006
005
006
00=,
005
005
OOh
006
007
00^
005
005
00^
ons
005
004
32317
CHLPPHYL
A
UG/L
0.6
00031
IMCDT LT
0.6
0.9
-------
STJ-ET PETKlEvAL DATE 77/01/32
waTj. EUrSOPrtlc'ATIvJN SURVEY
tPA-LAS VE6AS
320141
36 08 20.0 114 27 20.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/Lfl<£
DATE
FPOM
TO
75/02/35
HEPALtS
0999 FEET
DEPTH
75/06/12
75/11/31
75/12/03
0001 0
TIME DEPTH WATER
OF TF.MP
DAY FEET
13
13
13
13
13
13
13
13
13
13
08
08
08
06
08
08
06
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
Hi
35
35
35
35
35
35
35
35
35
35
40
40
40
40
40
40
40
45
45
45
45
45
45
4S
45
45
40
40
40
40
40
40
40
40
40
onoo
00 OS
001S
0030
0045
0060
0070
0120
0150
0300
0000
0005
0030
0060
0100
0150
0200
0000
0005
0031
0069
0095
0125
0165
0200
02JO
0000
0005
0015
0040
0075
Olio
0150
0190
0220
CFNT
11. Q
11.3
10.9
10.5
10.7
10.8
10.6
10. *5
10.5
10.5
30.7
20.7
18.8
15.1
11.9
10.5
9.H
15.7
15.7
15.7
15.7
15.7
15.?
13. ft
11."
11.3
16.?
16. •>
16.?
16.?
16.?
16.?
1 6 . .-,
14.=,
14. n
00300
00
1G/L
11.5
11.1
10.8
10.5
11.0
11.2
11.2
11.2
11.2
1 1.2
7.8
9.0
9.0
9.0
6.8
8.8
9.0
8.2
8.0
8.2
a.O
0.0
6.6
6.U
6.4
O.6
a.*
8.4
8.4
8.4
S.4
a.4
7.H
7.2
7 .6
00077
00094
CNOUCTVY
FIELO
INCHES
336
433
310
783
760
773
770
768
764
760
759
758
756
1 174
1 170
1126
1028
953
925
918
751
611
800
600
759
740
710
705
835
849
846
848
846
846
820
810
00400
PH
8.25
8.2S
P. 25
8.25
8.20
8.20
8.25
8.25
8.25
8.25
8.40
e.bO
8.60
8.30
8.30
8.2b
H.25
8.30
8.30
8.35
8.35
8.35
8.10
8.00
8.00
8.00
8.60
8.40
8.50
6.60
6.60
8.60
8.60
8.20
8.20
00410
T ALK
CAC03
HG/L
156
156
155
155
154
154
153
153
153
152
142
145
143
144
141
139
140
135
135
135
135
138
140
148
150
143
140
139
140
13rt
137
138
134
139
139
04001003
M CLASS
00610
NM3-N
TOTAL
I*G/L
0.030
0.020*
0.020
0.030K
0.030
0.020K
0.0?0
0.020
0.020K
0.020K
0.0«0
0.040
0.040
0.040
0.040
0.030
0.030
0.030K
0.0'OK
0.030K
0.0?OK
0.030K
0.030K
0.0?OK
0.030K
0.020K
0.030
0.030
0.030
0.0?0
0.030
0.030
0.020K
0.0?OK
0.020K
OP
00625
TOT KJEL
N
MR/L
0.200
0.200*
0.200*
0.200*
0.200K.
0.300
0.200K
O.?00
0.200K
0.200K
1.100
0.400
0.300
0.300
0.300
0.300
0.300
0.300K
O.?00*
0.300
O.ZOOK
0.300K
0.300K
O.HOOK
0.200*
0.200*
0.300
O.c'OO
O.OOOH
0.300
0.300
O.?00
O.?00*
0.000"
0.200*
00630
IN02&N03
N-TOTAL
*G/L
0.380
0.370
0.380
0.370
o.3°o
0.300
0.390
0.380
0.380
0.390
0.330
0.320
0.320
0.360
0.380
0.390
0.4QO
0.310
0.300
0.300
0.300
0.^00
0.370
0.430
0.420
0.410
0.330
0.330
0.320
0.320
0.320
0.320
0.340
0.430
0.430
00671
PHOS-OIS
MG/L P
0.004
0.003
0.015
0.004
0.013
0.004
0.004
0.011
0.013
0.005
0.007
0.004
0.003
0.003
0.002
0.00?
0.002K
0.003K
0.002K
0.003K
0.002K
0.005
0.003
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
K VALUE KNOWN TO BE LESS
THAN INDICATED
R VALUE INDICATES NO RESULT
REPORTED
-------
STORET RETRIEVAL DATF 77/01/22
NATL £UT»OPiICATIOM
EP&-LAS
380140
36 08 30.0 114 35 50." 3
LAKE MEAO
32003 NEVADA
/TYPA/AMBNT/LAKE
11EPALES 0*001002
0999 FEET DEPTH CLASS 00
DATE
FRO"
TO
75/02/25
75/06/11
'5/11/21
75/12/01
00665 32217 00031
TIME DEPTH PHOS-TOT CHIRPHYL IMCDT LT
OF A RFMNING
DAY FEET
14
14
14
14
14
14
14
14
14
14
14
15
15
15
15
15
15
15
13
13
13
!3
13
13
13
13
10
in
in
10
10
10
10
25
25
25
25
25
25
25
25
25
25
25
20
20
20
20
20
20
20
45
45
45
45
45
45
45
45
*5
45
f 4
45
45
-------
STOHET F^ETPIEtfAL JATE 77/01/22
*'ATL EUTROPHICATIO'M SURVEY
EPA-LAS VEGAS
/TYPA/AMBNT/LAKE
320142
36 04 00.0 114 18 50.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES
0999 FEET
04001002
OE^TH CLASS 00
onoio
DATE TIME DEPTH WATER
F*>OM OF TtMP
TO DAY FEET
75/02/25 10
10
10
10
10
10
10
10
10
10
75/06/12 11
11
1 I
11
11
11
11
75/1P/02 09
09
09
09
09
09
09
09
09
00
00
00
00
on
00
00
00
00
00
in
10
in
10
10
10
10
45
45
45
45
45
45
45
45
45
0000
0005
0015
0030
OObO
ooao
0110
0140
0170
020"
0000
ono^
0030
0061
0100
OloO
0200
0000
0005
00 IS
0040
0075
01 in
0150
0190
0220
CF.NT
11.0
10.9
10.7
10.*
10.^
10.5
10.4
10.4
10.4
10.?
22.1
21.4
2o. 1
15.0
11.4
10. T
9.-^
16.4
16.4
16.4
16.4
16.4
16.4
15.1
14.4
13.9
00300 00077 00094
oo Tr
830
834
835
332
815
795
770
00400 00410
PH T ALK
CAC03
StJ
8.25
8.25
8.25
8.25
8.25
8.25
8.25
8.25
8.25
8.25
8.65
P. 65
8.60
8.35
8.25
8.25
8.20
8.60
P. 60
8.50
8.50
8.50
8.20
8.20
8.20
MG/L
156
155
155
156
156
157
158
158
159
158
154
150
151
154
146
143
148
133
132
133
139
139
139
147
145
149
00610 00625 00630 00671
NH3-N TOT KJEL N02&N03 PMOS-OIS
TOTAL N N-TOTAL ORTHO
MG/L
0.0?0
0.020K
0.020K
0.020K
0.0?OK
0.020K
0.020K
0.020K
0.020K
0.020K
0.050
0.040
0.040
0.040
0.030
0.030
0.030
0.020K
0.020K
0.0?OK
O.OPO
0.020
0.020K
0.020
0.020
0.0?0
MG/L
0.500
0.300
0.200
0.200
0.200K
0.200K
0.200.K
0.200K
0.200K
0.200K
0.600
0.300
0.^00
0.200
0.300
0.200
0.^00
0.?OOK
0.200K
0.?OOK
0.200K
0.200K
0.200K
0.200^
0.200K
0.200K
MG/L
0.390
0.390
0.390
0.390
0.390
0.400
0.390
0.390
0.400
0.390
0.350
0.370
0.360
0.420
0.420
0.410
0.4QO
0.340
0.340
0.330
0.320
0.330
0.330
0.440
0.440
0.440
MG/L f
0.010
O.OOH
0.006
0.005
0.004
0.004
0.004
0.004
0.004
0.005
0.002K
0.017K
0.003
0.003
0.002
0.010K
0.003
0.002K
0.002K
0.00?K
0.002K
0.002K
0.002K
0.002K
0.002K
0.002K
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STQPET RETRIEVAL DATE 77/01/22
NiATL EUTROPhlCftTIOf:
EPA-LAS VEGAS
/TYPA/AMBNT/LAKE
320141
36 08 £0.0 114 ?7 20.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES
0999 FEET
DEPTH
04001002
CLASS 00
DATE
FRQM
TO
75/02/25
75/06/1?
75/11/21
75/12/02
00665 32217 00031
TIME DEPTH PHOS-TOT CHLHPHYL IMCDT LT
OF A PPMNING
DAY FEET MG/L P
13
13
13
13
13
13
13
13
13
13
oa
08
08
08
06
08
08
10
10
10
10
10
10
10
10
1Q
10
10
10
10
10
10
10
10
10
35
35
35
35
35
35
35
35
35
35
40
40
40
40
40
40
40
45
45
45
45
45
45
45
45
45
40
40
40
40
40
40
40
40
40
0000
0005
001^
0030
0045
0060
0070
0120
0150
0200
0000
0005
0030
0060
0100
0150
0200
0000
0005
0030*
0069
0095
0125
0165
0200
0230
0000
0005
0015
0040
0075
0110
0150
0190
0220
0.
0.
0.
0,
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0,
0.
0,
0.
0.
0,
0.
0.
0.
0,
o.
o.
0.
0
0
0
0
0
0
0
,011
,013
017
,013
,012
, 01 t
,01?
,011
,012
.011
,015
,00a
,006
, on s
,00^
, 004
.005
.010
.007
.007
. 006
, OOH
.006
.006
.005
.005
.005
.005
. 0 0 0 ><
. OQft1*
.005
.005
.005
. 0 0 0 U
.004
JG/L PEKCENT
1.0
0.5
1.2
1.0
-------
STO=tT RETRIEVAL QATE 77/(ll/22
NATL EUTHOPnICATIO'v S
cPA-|_AS
-------
STG&ET »ETQIEVAL OATE 77/01/22
NiATL FUT^OPHICATION SURVEY
EPA-LAS VEGAS
DATE TIME DEPTH
FRO* OF
TO DAY FEET
75/02/24 15 20 0000
15 20 0005
15 20 0015
15 20 0025
15 20 0031
75/06/12 15 00 0000
15 00 0005
15 00 001-;
15 00 0024
75/11/21 09 20 0001
09 20 0005
09 20 0015
09 20 0030
36 11 45.0 114 00 50.0 3
LAKE MEAD
04015 NEVADA
110191
11EPALES 04001002
0035 FEET DEPTH CLASS 00
00010
WATER
TEMP
CENT
9.3
8.2
7.9
7.8
7.7
22.6
19.2
17.5
16.9
13.7
13.7
12.6
10.4
00300
DO
MG/L
13.1
12.9
13.1
13.2
12.5
8.8
9.2
9.2
7.0
9.4
9.6
9.6
10.0
00077
THA.MSP
SECChI
INCHES
36
1?U
00094
CNDUCTVY
FIELD
MICROMhO
666
666
660
683
695
1075
1000
961
949
714
719
703
646
004QO
PM
su
8.40
8.40
8.40
ft. 40
8.40
8.45
H. 40
8.40
R.35
8.45
8.550
6.45
8.50
00410
T ALK
CAC03
MG/L
161
163
162
164
166
156
155
156
156
137
134
145
151
00610
NH3-N
TOTAL
MG/L
0.0?OK
0.020K
0.020K
0.020K
0.0?OK
0.040
0.030
0.030
0.030
0.020
0.020K
0.020K
0.020*
00625
TOT KJEL
N
MG/L
0.300
0.300
0.300
0.300
0.400
0.400
0.300
0.400
0.400
0.200*
0.200*
0.200*
0.200K
00630
N02S.N03
IM-TOTAL
MG/L
0.430
0.430
0.450
0.460
0.460
0.4MQ
0.500
0.510
0.520
O.?50
0.230
O.PVO
0.400
00671
PHOS-DIS
ORTHO
MG/L P
0.005
0.008
0.005
0.006
0.007
0.011K
0.013K
0.012K
0.004
0.002
0.002
0.002
0.002K
00665 32217
DATE TIME DEPTH PHOS-TOT CHLUPHYL
FROM OF 4
TO DAY FEtT MG/L P UG/L
75/02/24 15 20 0000 O.Olf, l.b
15 20 0005 0.013
15 20 0015 (1.016
15 20 0025 0.016
15 20 0031 O.Olf,
75/Oh/l?. 15 00 0000 0.00*> 0.7
15 00 0005 0.00*
15 00 0015 0.00«
15 00 0024 0.020
75/11/21 09 20 0000 0.010 2.1
09 20 0005 0.009
09 20 0015 • 0.009
04 20 0030 0.0?Q
00031
IMCDT LT
PFKCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
RET^IEv/AL 'JfiTE 77/01/22
NATL EUT^OPrtlCATTJU SURVEY
E.PA-LAS V/FGAS
320142
36 04 00.0 114 18 50.0 3
LAKE MEAD
32003 NEVADA
110191
11EPALES 04001002
0999 FEET DEPTH CLASS 00
DOTE
TO
75/02/25
75/06/12
75/12/0?
TIME t
OF
00665 32217 00031
)EPT^ PHOS-TOT CHLRPHYL INCDT LT
DAY FEET
10
10
10
10
10
10
10
10
10
10
11
11
11
11
11
11
11
09
09
09
09
09
09
09
09
09
00
00
00
00
00
00
00
00
00
00
10
10
10
10
10
10
10
45
45
45
45
&5
45
45
45
45
0000
0005
0015
0030
0050
OOMO
0110
0140
0170
0200
0000
oooc.
0030
0060
0100
0150
0200
0000
0005
001^
0040
0075
01 10
0150
0190
0220
wG/L P UG/L DFRCENT
0.015 0.5
0.011
0.01 1
0 . U 1 0
0.011
0.010
o.oov
0.013
0.010
0.011
o .O0h o.a
0.005
0.006
0.006
0.007
0.005
0.00 =
0.005 1.0
0.005
0.005
0.006
0.005
0.006
0.005
0.004
0.006
-------
STOPET RtT-?IEVAL DATE 77/01/2?
NATX EUTriOPHlCATIO'v SURVEY
EPA-LAS VEGAS
/TYPA/AMBNT/LAKE
DATE
FPQM
TO
75/03/35
75/06/12
75/11/21
00010
TIME DEPTH wATEW
OF TEMP
DAY FEET
08
08
08
08-
08
08
08
08
14
14
14
14
14
14
14
09
09
09
oy
09
09
09
09
09
45
45
45
45
45
45
45
45
15
15
15
15
15
15
15
45
45
45
45
45
45
45
<*5
45
0000
0005
0015
0060
0095
0120
0165
0195
0000
000s
0030
0060
0100
0150
0195
0000
OOO1^
0025
004P
0090
0120
0145
0190
0326
CENT
11
10
10
10
10
10
10
8
24
24
21
17
13
10
10
15
16
15
15
15
14
14
11
10
.0
.9
.*
.4
.4
.3
.2
.8
.7
.5
.?
.0
.5
.8
.4
.9
.0
.9
.9
.9
.7
.1
.7
.9
00300
DO
MG/L
12
12
12
12
12
12
12
14
9
9
9
8
8
8
8
9
8
H
3
8
8
8
4
3
.8
.8
.9
.0
.1
.2
.4
.2
.0
.2
.0
.b
.2
.0
.0
.0
.6
.4
.4
.4
.4
.2
.6
. 6
330143
36 06 23.0 114 07 05.0 3
LAKE MEAU
33003 NEVADA
110191
1 1EPALES
0999 FEET
04001002
DEPTH CLASS 00
00094
CNOUCTVY
FIELD
MICROMHO
714
710
703
701
700
697
695
667
1206
1143
1077
977
903
853
849
744
780
>53
780
784
711
765
687
672
00400
Pri
Sii
8.30
8.40
8.40
8.40
8.35
8.30
8.30
8.35
8.50
8.50
8.50
8.30
8.20
8.20
8.30
8.50
8.50
8.50
8.50
6.50
b.40
8.30
7.50
7.80
00410
T ALK
CAC03
MG/L
159
162
145
148
150
152
152
160
158
159
156
157
160
154
155
138
137
138
137
136
140
145
150
156
00610
MH3-N
TOTAL
MG/L
0.040
0.020K
0.020K
0.020
0.020K
0.020K
0.020K
0.020K
0.070
0.030
0.030
0.040
0.030
0.030
0.030
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.040
00625
TOT KJEL
N
MG/L
0.800
0.300
0.400
0.300
0.400
0. 300
0.400
0.400
0.700
0.400
0.200
0. 300
0.200
0.300
0.300
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K.
00630
N02&N03
N-TOTAL
MG/L
0.380
0.380
0.390
0.370
0.370
0.370
0.380
0.420
0.410
0.410
0.430
0.480
0.490
0.470
0.450
0.250
O.?40
0.240
0.240
O.?40
0.300
0.320
0.480
0.430
00671
PHOS-DIS
ORThO
MG/L P
0.008
0.006
0.005
0.005
0.006
0.008
0.008
0.008
0.005
0.005
0.004
0 . 0 1 1 K
0.004
0.003
0.005
0.002
0.002
0.002K
0.002K
0.002K
0.002K
0.002K
0.003K
0.002K
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/25
NATL EUTROPHICATION SURVEY
EPA-LAS VEGAS
/TYPA/AMBNT/LAKE
DATE
FROM
TO
75/02/24
75/06/12
75/11/21
TIME DEPTH
OF
DAY FEET
14 30 0000
14 30 0005
U 30 0015
14 30 0021
15 40 0000
15 40 0005
15 40 0012
09 00 0000
09 00 0005
09 00 0015
00010
WATER
TEMP
CENT
7.9
7.Q
7.8
7.8
15.8
15.4
15.3
8.6
8.4
8.5
00300
DO
MG/L
12.9
13.3
13.8
14.0
9.6
9.2
9.8
10.2
10.4
- 10.4
00077
TRANSP
SECCHI
INCHES
36
18
22
00094
CNDUCTVY
FIELD
MICROMHO
624
624
622
622
929
920
919
570
561
736
320145
36 08 30.0 113 58 23.0 3
LAKE MEAD
04015 NEVADA
110191
11EPALES
0025 FEET
DEPTH
00400
PH
su
8.30
8.30
8.30
8.30
8.35
8.40
8.40
8.20
8.25
8.25
00410
T ALK
CAC03
MG/L
154
155
155
155
147
149
149
154
149
151
04001003
H CLASS
00610
NH3-N
TOTAL
MG/L
0.020
0.020K
0.020K
0.020K
0.050
0.020K
0.020
0.030
0.020
0.020
00
00625
TOT KJEL
N
MG/L
0.300
0.200
0.300
0.300
0.600
0.500
0.300
0.200K
0.200K
0.200K
00630
N02&N03
N-TOTAL
MG/L
0.490
0.490
0.490
0.500
0.500
0.490
0.500
0.470
0.480
0.480
00671
PHOS-DIS
ORTHO
MG/L P
0.009
0.008
0.008
0.018
0.004
0.003
0.003
0.009
0.005
0.004
00665 32217
DATE TIME DEPTH PHOS-TOT CHLRPHYL
FROM OF A
TO DAY FEET MG/L P UG/L
75/02/24 14 30 0000 0.018 0.7
14 30 0005 0.021
14 30 0015 0.021
14 30 0021 0.035
75/06/12 15 40 0000 0.013 1.1
15 40 0005 0.015
15 40 0012 0.020
75/11/21 09 00 0000 0.015 0.7
09 00 0005 0.009
09 00 0015 0.025
00031
IMCDT LT
RFMNING
PERCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STO^ET RETRIEVAL U&Tt 77/01/22
NATL PUTHOPHICATION susvev
EPA-LAS VEGAS
320151
36 05 02.0 11*
LAKE MEAD
32003 NEVADA
47 30.0 3
/TYPA/AM8NT/LAKE
1UPALES 760303 04001002
0103 FEET DEPTH CLASS oo
DATE
FROM
TO
75/12/04
7b/12/08
TIME
OF
DA/
10 00
10 00
10 00
10 00
10 00
10 oo
1000
10 00
13 20
13 20
13 20
13 20
13 20
DEPTH
FEET
0000
0015
0020
0040
005n
0060
0060
0100
0000
0015
0050
0100
0163
00010
WATER '
TEMP
CENT
16.2
16.?
16.2
16.?
16.2
16.2
16.?
16.2
14.7
13. *
13.3
1 3 . «
13.7
00300
DO
MG/L
5.0
7.6
5.4
9.0
6.0
7.0
8.2
6.*
8.4
8.6
8.4
8.2
8.0
ooo n
TKANSP O
SECCHI FIELD
INCHES M]
600
236
9*
TVY
MHO
865
904
905
905
905
909
906
900
803
795
799
799
799
00400
PH
SU
8.00
8.VO
H.OO
s.10
8.10
8.10
8.10
8.10
7.70
7.90
7.85
7.80
7.80
00410
T ALK
CAC03
MG/L
127
120
126
121
120
122
123
118
130
131
129
129
132
00610
NH3-N
TOTAL
MG/L
0.020K
0.020
0.020K
0.050
0.0?0
0.030
0.020
0.020
0.020
0.030
0.030
0.040
0.040
00625
TOT KJEL
N
MG/L
0.200K
0.200
0.200K
0.200
0.200
0.200
0.200
- 0.200
0.200K
0.200K
0.200K
0.300
0.200
00610
N02&N03
N-TOTAL
MG/L
0.240
0.240
0.230
0.240
O.?40
O.?40
0.240
0.240
O.?40
0.230
O.?30
p.?30
0.750
00671
PHOS-OIS
OPTHO
MG/L P
0.005
0.004
0,004
0.006
0.004
0.004
0.004
0.004
0.006
0.010
0.010
0.012
0.020
00665
DATE TIME DEPTH PHOS-TOT
FROM OF
TO DAY FEET MG/L P
75/12/04 10 00 0000 0.019
10 00 0015 0.021
10 00 0020 0.021
10 00 0040 0.023
10 00 0051 0.020
10 00 006" O.OHO
10 00 0080 0.020
10 00 0100 0.04?
75/12/08 13 20 0000 0.021
13 20 001
-------
STOHET RETRIEVAL DATE 77/01/22
NATL FUTROPHICATIUN SURVEY
EPA-LAS VEGAS
320152
36 05 23.0 11* 47 20.0 3
LAKE MEAD
32003 NEVADA
11EPALES 760303 04001002
0999 FEET DEPTH CLASS 00
00010
DATE TIME DEPTH WATER
FRO" OF TEMP
TO DAY FEET
75/12/04 H
11
11
11
11
11
11
11
11
11
11
11
75/12/09 13
13
13
13
13
13
on
00
00
00
on
00
00
00
00
00
00
00
20
20
20
20
20
2n
noon
0015
0030
0050
0070
OOB5
0100
0120
0140
0160
OltiO
0210
0000
000^
0015
0050
Oion
0210
CENT
16.3
16.?
16.2
16.2
16.2
16.2
16. 1
If. 1
16.0
16.0
15. f.
14.?
14.2
14.?
14.Q
13. S
13. p
11. T
00300 00077 00094
DO THAMSP CNOUCTVY
SECCMl FIELD
MG/L INCHES MICROMHO
7.3
6.2
6.6
6.6
8.0
5.8
8.2
8.2
8.4
6.2
5.8
5.0
8.8
9.6
9.2
8.4
8.1)
6.4
18 900
898
900
898
898
897
899
905
902
902
908
839
168 785
«00
795
790
790
720
00400 00410
PH T ALK
CAC03
su
8.10
8.10
8.10
7.80
8.00
8.00
8.00
8.00
8.00
ft. 00
7.60
«. 00
7.95
8.00
7.90
V.80
7.50
7.45
MG/L
124
126
128
130
127
130
129
128
130
130
138
133
121
125
124
122
132
129
00610 00625 00630 00671
NH3-N TOT KJEL NOP&N03 PHOS-DIS
TOTAL N N-TOTAL OPTnO
MG/L
0.020K
0.020K
0.020
0.020K
0.020
0.020
0.020
0.030
0.030
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
0.020
0.020K
0.020K
MG/L
0.200K
0.200K
0.200
0.400
0.200
0.200
0.200K
0.200*
0.200K
0.200
0.200K
0.200K
0.200
0.200K
0.200K
0.200
0.200
0.200
MG/L
0.240
O.P30
O.P30
O.?30
O.?30
0.220
0.220
0.230
0.230
0.230
0.450
0.380
"0.230
0.240
0.240
0.230
0.420
0.430
MG/L P
0.006
0.006
0.005
0.007
0.006
0.007
o.ooa
0.012
0.012
0.011
0.017
0.012
0.006
o.oos
0.005
O.OOH
0.009
0.009
0066S
TIME DEPTH PHOS-TOT
OF
TO DAY FEET MG/L P
DATE
75/12/04
75/12/09
11 00
11 00
11 on
1
1
1
1
1
1
1
1
1
00
00
00
on
00
00
00
on
00
13 20
13 20
13 20
13 20
13 20
13 2n
0000
001S
0030
0050
0070
0085
Olon
0120
0140
oi^n
oion
0210
ooon
0005
001-^
OObO
oion
021"
0.017
0.020
0.019
0.020
0.021
0.021
0.0?'--
0.02 =
0.026
O.OP7
n .ii-?.-i
0.01^.
0.01^1
0.0??
G.Olo
n.oia
0.017
0 . 0 1 f
32217
CHLWPHYL
A
U6/L
2.d
00031
IMCDT LT
PFKCENT
K VALUE KNOWN TO BE
LESS THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/22
NATL EUTROPhlCATICK
EPA-LAS VEGAS
320153
36 05 43.0 11*
LAKE MEAD
32003 NEVADA
47 12.0 3
/TYPA/AMBNT/LAKE
DATE TI*>E DEPTH
F30M OF
TO DAY FEET
75/12/09 10 35 0001
10 35 0005
10 35 0015
10 35 0050
10 35 Oion
10 35 0210
DATE TIME DEPTH
FROM Of-
TO DAY FEET
75/12/09 10 35 0000
10 35 0005
10 35 001^
10 35 0050
10 35 0100
10 35 0210-
HEPALES 760303 04001002
0999 FEET DEPTH CLASS 00
ooin
TER
fc.MP
ENT
14.?
14.2
l*.l
14. n
13.8
11.6
0665
S-TOT
/L f
U . 0 1 7
O.Olfl
0.017
0.020
0.019
0.016
00300 00077
DO THAN'''3
cECCHI
MG/L INCHES
8.4 240
8.4
8.4
6.4
6.2
6.4
32217 00031
CHLHPHYL IMCDT LT
A RF^NlNG
UG/L PERCENT
4.2
00094
CNDUCTVY
FIELD
MICROMHU
810
790
765
820
«20
760
00077
T^ ANSP
cECCHI
INCHES
240
00094
CNDUCTVY
FIELD
MICROMHO
810
790
765
820
«20
760
00400
PH
SO
7.70
7.70
7.80
7.60
7.60
7.30
00410
T ALK
CAC03
MG/L
132
129
129
130
124
139
00610
NH3-N
TOTAL
MG/L
0.020K
0.020
0.020
0.020
0.030
0.020K
00625
TOT KJEL
N
MG/L
0.200K
0.200
0.200K
0.200K
0.200K
0.200
006^0
N028.N03
N-TOTAL
MG/L
0.240
0.240
O.P40
0.240
O.?30
0.430
00671
PHOS-OIS
ORTHO
MG/L P
0.005
o.ooa
0.006
0.007
0.009
0.012
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOKET HtTKItVAL
NATL
IrPA-LAS VEGAS
77/01/33
SU-ivEY
320154
36 05 55.0 11* 47 07.0 3
LAKE MEAD
33003 NEVADA
11EPALES 760303 04001003
0999 FEET DEPTH CLASS 00
DATF
FRO*
TO
75/12/09
TIME DEPTH
OF
DAY FEET
10 00 0000
10 00 0005
10 00 0015
10 00 0050
10 on oion
10 00 0310
00010
WATEK
TEMP
CENT
14.1
14.1
14.1
14.1
13.9
11. 6
00300
DO
MG/L
8.6
fl.4
8.4
8.2
3.0
6.4
00077
TRftNSP
<=ECCHI
INCHES
210
00094
CNOUCTVY
FIELD
MICROMHO
7S>0
800
830
790
780
720
00400
PH
su
7.70
7.70
7.70
7.70
7.50
7.40
00410
T ALK
CAC03
Mfj/L
133
131
133
134
134
145
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.020K
0.020
0.0?0
0.020K
00625
TOT KJEL
N
MG/L
0.200K
0.200
0.200K
0.200K
0.200
O.POOK
00630
NO?f,N03
N-TOTAL
"
-------
STOPET RETRIEVAL DATE 77/01/22
NATL EUTROPHICATION SURVEY
EPA-LAS VEGAS
330155
36 06 13.0 114 46 56.0 3
LAKE MEAD
32003 'MEVAOA
/TYPA/AM8NT/LAKE
11EPALES 760303 04001002
0172 FEET DEPTH CLASS 00
DATE
FROM
TO
75/12/06
75/12/09
TIME
OF
DAY
14 15
14 15
14 15
14 15
14 15
09 00
09 00
09 00
09 00
09 00
09 00
DEPTH
FEET
0000
0015
0050
0100
oib3
0000
0005
0015
0050
0100
0140
00010
HATER
TtMP
CENT
14.
14.
14.
13.
13,
14.
14,
14,
14,
13,
13,
00300 00077 00094
DO TKANSP CNOUCTVY
00400
PH
SECCHI FIELD
,2
, )
,0
,9
,7
>n
,1
,0
.0
.9
,q
MG/L
8
8
7
8
8
8
8
8
8
8
ft
INCHES rt]
.8 256
.2
.8
.2
.2
.6 240
.2
.4
.4
.4
.2
!CROMHO
789
800
792
790
789
780
800
805
805
790
800
su
7.90
7.80
7.80
7.80
7.60
7.70
7.70
7.60
7.60
7.80
7.60
00410
T ALK
CAC03
MG/L
132
132
134
133
131
133
136
133
132
133
134
00610 00625 00630
NH3-N TOT KJEL N026.N03
TOTAL
MG/L
0.020K
0.020K
0.020
0.030
0.030
0.020K
0.020K
0.020K
0.020K
0.020
0.020
N N-TOTAL
MG/L
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200*
0.200
0.200
0.200
0.200K
MG/L
0.240
O.?40
0.240
0.230
O.P40
0.230
0.240
0.230
0.230
0.220
0.230
00671
PHOS-DIS
OSTHO
MG/L P
0.005
0.004
0.005
0.008
0.010
0.005
0.005
0.004
0.003
0.008
0.009
TO
OF
DAY FEET
75/12/08 14 15 0000
14 15 0015
14 15 0050
14 15 0100
14 15 016*
75/12/09 09 00 0000
09 00 OOOS
09 00 001S
09 00 OOSO
09 00 0100
09 00 0140
0665
S-TOT
/L P
0.018
0.017
n . o l H
0.020
0.02R
0.016
0.019
0.017
0.01S
0 . 0 I o
0 . U 1 9
32217
CHLHPrlYL
A
UG/L
3.2
4.2
00031
INCDT LT
RFPINING
PFRCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL CMTE 7//oi/?2
NftTL EUTROPHlCATI'J* ->iMVEY
EPA-LAS VEGAS
320156
36 06 13.0 114 46 03.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
00010
QATK TIME DEPTH
FrfO« OF
TO DAY FEET CENT
75/12/OB 15 05 0000 l4.a
15 05 0015 14.?
15 05 0050 14.1
15 05 0100 14.1
15 05 019^ 12.0
8.B
8.4
8.2
6.0
8.2
00300 00077
DO TRANbP O
<=EccHi FIELD
INCHES MI
216
11EPALES 760303 04001002
0201 FEET DEPTH CLASS 00
94
TVY
MHO
634
780
791
780
765
00400
PH
SU
7.85
7.85
7.80
7.60
7.50
00410
T ALK
CACU3
MG/L
13?
136
129
128
140
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.040
0.030
0.020K
00625
TOT KJEL
N
MG/L
O.«»00
0.600
0.200
0.200
0.200K
006.^0
N02i,N03
N-TOTAL
MG/L
O.?50
0.240
O.PftO
O.?50
0.430
00h71
PHOS-DIS
OPTHO
MG/L P
0.005
0.003
0.009
0.006
0.008
00665 32217
DATE TIME DEPTH PHOS-TOT CnLRPHYL
FkO" Or A
TO DAY FEET MG/L P UG/L
75/12/08 15 05 0000 0.017 3.8
15 05 001=. 0.01Q
15 05 0050 0.017
15 05 0100 O.nm
15 05 019^ O.OU
00031
IMCDT LT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOP.ET RETRIEVAL DATE 77/01/22
NATL EUTROPHICATION SURVEY
EFA-LAS VEGAS
320lb7
36 06 36.0 114 45 42.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMSNT/LAKE
DATE TIME DEPTH
FRO" OF
TO DAY FEET
75/12/OK 14 40 0000
14 40 0015
14 40 0050
14 40 0100
14 40 01B9
11EPALES 760303 04001002
0194 FEET DEPTH CLASS 00
010
ER
HP
NT
14.4
14.?
14.?
14.?
12.3
00300
DO
MG/L
8.8
8.6
8.2
8.2
5.8
00077
TRANSP
<;ECCHI
INCHES
192
00094
CNOUCTVY
FIELD
MICKOMHU
805
794
818
792
742
00400
PH
su
7.90
7.85
7.80
7.80
7.60
00410
T ALK
CAC03
MG/L
127
129
130
132
142
00610
NH3-N
TOTAL
MG/L
0.020K
0.020
0.020K
0.020K
0.020K
00625
TOT KJtL
N
MG/L
0.200K
0.200K
0.200K
0.200
0.200
006?0
N02&.N03
N-TOTAL
MG/L
0.230
0.250
O.?50
0.240
0.430
00671
PHOS-DIS
ORTHO
MG/L P
0.005
0.005
0.004
0.005
0.011
00665 32217
DATE TIME DEPTH PhOS-TOT CHLRPHYL
FROM OF A
TO DAY FEET MG/L P UG/L
75/12/06 1* 40 0000 0.015 5.4
14 40 0015 0.014
14 40 0050 0.01»
14 40 0100 0.016
14 40 01H9 0.014
00031
IMCDT LT
PFRCE^T
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORE! RETRIEVAL JATE 77/01/22
NATL EUTSOPrtlCATIO* SURVEY
EPA-LAS VFGA5
320159
3h 07 38.0 114 51 45.0 3
LAKE MEAD
3?.U03 NEVADA
/TYPA/AMBNT/LA>
-------
STORET RETRIEVAL DATE 77/01/22
NATL EUTROPnICATION SURVEY
EPA-LAS VEGAS
320159
36 07 37.0 114 51 16.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AM8NT/LAKE
00010
DATE TIME DEPTH WATER
FRO" OK TEMP
TO DAY FEET CENT
75/12/10 13 35 0000
13 35 0007
13.6
13.6
00300
DO
MG/L
10.6
11.6
00077
FIELD
INCHES MICRO
11EPALES 760303 04001002
0009 FEET DEPTH CLASS 00
94
TVY
MHO
787
776
00400
Ph
su
8.10
8.24
00410
T ALK
CAC03
MG/L
127
127
00610
NH3-N
TOTAL
MG/L
o.oaoK
0.020K
00625
TOT KJEL
N
MG/L
0.200
0.200K
00630
N02&N03
N-TOTAL
MG/L
0.160
0.130
00671
PHOS-DIS
ORTHO
MG/L P
0,007
0.005
00665
DATE TIME DEPTH PHOS-TOT
FRO" OF
TO DAY FEET MG/L P
75/12/10 13 35 0000
13 35 0007
0.051
0.044
32317
CHLRPHYL
A
UG/L
19.9
00031
IMCDT LT
RFMNING
PERCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOPET RETRIEVAL ti^TE 77/01/2?
NATL EUTHOPhlCATION' SURVEY
tPA-i_AS VEGAS
320160
36 07 13.0 114 51 23.0 3
LAK.E MEAD
32003 NEVADA
/TYPA/AMBN'T/LAKE
DATE TIME DEPTH
FPOM OF
TO DAY FEET
75/12/10 0=) 30 0001
09 30 0005
09 30 001^
09 30 0030
09 30 0050
09 30 0065
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/12/10 09 30 0000
09 30 0005
09 30 001^
09 30 003"
09 30 0050
09 30 0065
llEPALtS 760303 04001002
006« FEET DEPTH CLASS 00
0010
TEK
EMP
ENT
13.6
13.6
13.
-------
STORET RETRIEVAL 04TE 77/01/22
MAIL FUTROPhlCATION SURVEY
EPA-LAS VEGAS
330161
36 07 07.0 114 50 58.0 3
LAKE MEAD
33003 NEVADA
/TYPA/AMBNT/LAKE
00010 00300
DATE TIME DEPTH WATER DO
FROM OF TEMP
TO DAY FEET CENT MG/L
75/12/10 10 00 0000 13.6 8.8
10 00 0005 13.6 8.8
10 00 0015 13.6 9.0
10 00 0035 13.6 9.6
10 00 0050 13.6 8.6
10 00 0075 13.6 ' 8.6
10 00 0090 13.5 9.0
00077
FIELD
INCHES Ml
156
11EPALES 760303 04001002
0094 FEET DEPTH CLASS 00
9
-------
STOPET RETRIEVAL DATE 77/01/82
MAIL EUTROPHICATION SUHVEY
EPA-LAS VEGAS
320162
36 06 »8.0 114 50 47.0
LAKE MEAD
32003 NEVADA
/TYPA/AMRNT/LAKE
DATE TIME DEPTH
FRO« OF
TO DAY FEET
75/12/10 13 50 0000
13 50 000^
13 50 0015
13 50 0035
11EPALES 760303 04001002
0039 FEET DEPTH CLASS 00
00010
WATER
TEMP
CENT
13.9
13. R
13.7
13. b
00300
00
MG/L
9.6
9.6
9.0
9.6
00077
TKANSP Cr\
SECCHI FIELD
INCHES MI
130
94
TVY
MHO
788
797
800
793
00400
PH
SU
7.80
7.80
7.80
7.81
00410
T ALK
CAC03
MG/L
127
129
128
123
00610
NH3-N
TOTAL
MG/L
0.020K
O.OPOK
0.020K
0.020K
00635
TOT KJEL
N
MG/L
0.200K
0.200
0.200
0.200K
00610
N02&N03
N-TOTAL
MG/L
0.200
0.210
O.?00
0.220
00671
PHOS-DIS
ORTHO
Mfi/L P
0.005
0.005
0.004
0.004
00665 32217
DATE TI*E DEPTH PHOS-TOT CHLHPHYL
FPO* OK A
TO DAY FF.ET MG/L P UG/L
75/12/10 13 50 0000 0.02? 10.4
13 50 0005 0.0?5
13 50 0015 0.021
13 50 003b 0.021
00031
IMCDT LT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/32
NATL EUTROPi-aCATION SURVEY
EPA-LAS VEGAS
330163
36 07 07.0 114 50 16.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
11EPALES 760303 0400100?
0146 FEET OEPTH CLASS 00
DATE TU'E
FRO"1 OF
TO DAY FEET
75/12/10 10 30 0000
10 30 0005
10 30 0015
10 30 0030
10 30 0050
10 30 0100
10 30 0140
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/12/10 10 30 0000
10 30 0005
10 30 0015
10 30 0030
10 30 005"
10 30 0100
10 30 0140
0010
,TER
•FMR
:ENT
13.3
13.8
13.7
13.7
13.7
13.6
13.0
0665
S-TOT
/L P
0.019
0.021
0.020
0.023
0.02?
00300 00077
00 TKANSP
^ECChl
MG/L INCHES
9.0 156
8.8
8.6
9.0
9.2
8.4
8.4
32217 00031
CHLSPHYL IMCDT LT
a SFMNING
UG/L ^CHCENT
7.0
00094
CNDUCTVY
FIELD
MICROMHO
785
787
795
793
797
792
1017
00400
PH
su
7.30
7.2b
7.25
7.22
7.25
7.28
7.29
00410
T ALK
CAC03
MG/L
128
128
126
127
127
130
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00625 00630
TOT KJtL N02S.N03
N N-TOTAL
MG/L MG/L
0.300
0.200
0.300
0.300
0.200
0.200K
0.200K
0.210
0.220
0.210
O.P10
0.210
0.220
0.230
00671
PHOS-DIS
OHTHO
MG/L P
0.004
0.005
0.005
0.005
0.007
0.018
0.031
0.044
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/32
NATL EUTROPhlCATIOM SURVEY
EPA-LAS VEGAS
330164
36 06 55.0 114 06 55.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
11EPALES 760310 04001003
0150 FEET DEPTH CLASS 00
DATE
FRO'1
TO
TIME DEPTH
OF
DAY FEET
75/13/09 14 45-0000
DATE
F*OM
TO
14 45 0005
14 45 0015
14 45 0050
14 45 0100
14 45 0145
TIME DEPTH
OF
DAY FEET
00010
WATER
TEMP
CENT
14.2
14.0
13.9
13. *
13.7
13.*
00665
PHOS-TOT
MG/L P
00300
DO
MG/L
9.2
9.0
8.6
8.4
8.6
8.8
32217
CHLRPHYL
i
UG/L
00077 00094
THANSP CNDUCTVY
^ECCHI FIELD
INCHES MICROMHO
168
00031
IMCOT LT
OFMNING
PERCENT
795
795
790
790
815
790
75/12/09 14 45 0000 0.0?3
14 45 0005 0.021
14 45 0015 0.020
14 45 0050 0.020
14 45 0100 0.0??
14 45 0145 0.031
1.8
00400
PH
SU
7.80
7.80
7.79
7.75
7.80
7.85
00410
T ALK
CAC03
MG/L
130
131
131
131
130
126
00610
NH3-N
TOTAL
MG/L
0.020
0.030
0.020K
0.020K
0.020
0.020
00625 00630
TOT KJEL N02&N03
N N-TOTAL
MG/L MG/L
0.200
0.200K
0.200K
0.200K
0.200K
0.300
0.220
0.330
O.?20
0.330
0.320
0.320
00671
PHOS-DIS
ORTHO
MG/L P
0.009
0.007
0.006
0.006
0.010
0.011
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOPET RETSIEVAL DATE 77/01/22
NATL EUTPOPhlCATION" SURVEY
EPA-LAS VEGAS
320165
36 06 29.0 114 49 55.0 3
LAKE MEAD
32003 NEVADA
/TYMA/AMBNT/LAKE
11EPALES 760303 04001002
0062 FEET DEPTH CLASS 00
00010
WATER
TEMP
CENT
13.9
13. a
13.8
13.6
13.6
00300
00
MG/L
9.6
9.0
9.0
9.0
9.2
00077
ThANSP
«;ECCMl
INCHES
140
00094
CNDUCTVY
FIELD
MICROMHO
793
795
793
787
788
00400
PH
su
7.86
7.80
7.80
7.73
7.70
00410
T ALK
CAC03
MG/L
123
123
125
124
124
00610
NH3-N
TOTAL
MG/L
O.OPOK
0.020K
0.020K
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200K
0.200K
0.200
0.200
0.200
00630
N02S.N03
N-TOTAL
MG/L
0.220
0.220
0.220
O.?10
0.210
00671
PHOS-DIS
ORTnO
MG/L P
0.006
0.006
0.006
Q.006
0.005
UATE
TO
OK
DAY FEET
75/12/ln 14 00 0000
14 00 0005
14 00 0015
14 00 0030
14 00 OObB
0665
S-TOT
/L P
0.021
0.021
0.0??
0.021
0.02?
32217
CHLRPHYL
a
UG/L
7.6
00031
IMCDT LT
QFMNlNG
PFfcCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 77/01/22
NATL EUTROPHICATIOM
EPA-LAS VEGAS
320167
36 06 18.0 114 46 52.0 3
LAKE MEAO
32003 NEVADA
/TYPA/AMBNT/LAKE
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/12/09 14 10 0000
14 10 0005
14 10 0015
14 10 0050
14 10 0100
14 10 0210
11EPALES 760310 04001002
0999 FEET DEPTH CLASS 00
010
ER
MR
NT
14.
14.
14.
13.
13.
11.
I
3
0
9
9
f*
00300
DO
MG/L
9.2
9.0
8.6
8.4
8.4
7.0
00077
TRANiSP
cECCHl
INCHES
156
00094
CNDUCTVY
FIELD
MICROMHO
790
800
795
795
795
735
00400
PH
SU
7.
7.
7.
7.
7.
7.
80
85
80
75
70
78
00410
T ALK
CAC03
MG/L
118
120
122
119
125
125
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
'0.020
0.020
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200
0.200
0.200K
0.200K
0.200K
0.200K
00630
N02&N03
N-TOTAL
MG/L
0.240
0.240
0.230
0.230
O.?30
0.230
00671
PHOS-OIS
ORTHO
MG/L P
0.005
0.005
0.006
0.006
0.007
0.006
DATE
0066S 32217
TIME DEPTH PHOS-TOT CHLRPHYL
OF A
TO DAY FEET MG/L P UG/L
75/12/09 14 10 0000 0.01Q 2.6
14 10 000*5 0.019
14 in 001^ 0.020
14 10 0050 0.013
14 10 0100 0.01P,
14 10 0210 0.021
00031
IMCDT LT
PFMNING
PFRCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORE! RETRIEVAL DATE 77/01/a?
NATL tUT»()PnICATIOM SURVEY
EPA-LAS VEGAS
380166
36 07 30.0 114 49 33.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AM8NT/LAKE
DATE TIwE
FROM OF
TO DAY
0001 0
DEPTH WATEK
TEMP
FEET CENT
75/12/10
11
11
11
11
05
05
05
05
noon
0005
0015
0025
13.9
13. q
13.R
13.7
00300 00077 0009*
DO THANSP CNDUCTVY
CECCHI FIELD
MG/L INCHES MICROMHO
9.4
9.2
9.2
9.2
132
601
789
787
789
11EPALES 7603U3 04001002
0029 FEET DEPTH CLASS 00
00400
PH
su
7.36
7.40
7.39
7.30
00410
T ALK
CAC03
MG/L
127
128
129
129
00610
NH3-N
TOTAL
MG/L
00625
TOT KJEL
N
MG/L
00630
N02S.N03
N-TOTAL
MG/L
00671
PHOS-DIS
OftTHO
MG/L P
0.020K
0.020K
0.020K
U.020K
0.200
0.200K
0.200K
0.200K
0.200
O.?00
0.200
O.?00
0.005
0,003
0.003
0.003
00665 32217 00031
DATE TIME DEPTH PHOS-TOT CHLRPHYL INCDT LT
TO OAr FEET MG/L P UG/L PFKCLNT
7^/12/10 11 05 0000
11 05 0005
11 05 0015
11 05 0025
0.020 10.0
0.021
0.016
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORtT RETRIEVAL UAT>: 77/01/22
NATL EUTPOPHlCATIO". SIMV/EY
EPA-LAS VEGAS
330168
36 0* 45.0 114 48 06.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
DATE
TO
TIf'E DEPTH
OF
DAY FEET
75/12/10 14 40 0000
14 40 0005
14 40 001S
14 40 003d
14 40 0050
11EPALES 760303 04001002
0055 FEET DEPTH CLASS 00
010
ER
MP
NT
14.
14.
13.
13.
13.
1
0
R
g
rt
00300
DO
MG/L
9.
9.
8.
8.
9.
2
0
6
6
2
00077
THA'viSP
cECCrll
INCHES
120
00094
CNOUCTVY
FIELD
MICROMriO
794
814
796
808
802
00400
PH
SU
7.67
7.59
7.60
7.50
7.5B
00410
T ALK
CAC03
MG/L
119
116
119
120
121
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200
0.200K
0.200K
0.200K
0.200K
00630
N02^N03
N-TOTAL
MG/L
0.220
0.230
0.230
O.?30
0.220
00671
PHOS-DIS
ORTHO
MG/L P
0.006
0.006
0.006
0.006
0.006
00665
OflTE TIME DEPTH PHOS-TOT
FRO" OF
TO DAY FEET MG/L P
75/12/10 14 40 0000 0.0?^
14 40 OOO'1' O.Olv
14 40 001S (J.01
-------
STORET RETRIEVAL DATE 77/01/32
NATL EUTROPlICATIO". SURVEY
EPA-LAS VEGAS
330170
3d 05 00.0 114 46 01.0 3
LAKE MEAD
33003 NEVADA
/TYPA/AM8NT/LAKE
11EPALES 760303 0400100?
0999 FEET DEPTH CLASS 00
DATE
FROM
TO
75/12/11
TIME DEPTH
OF
DAY FEET
10 40 0000
10 40 0005
10 40 0015
10 40 0030
10 40 0050
10 40 0100
10 40 0215
00010
WATER
TEMP
CENT
14.0
14.1
14.1
14.0
14.0
13.9
11.7
00300
DO
MG/L
8.6
8.8
8.6
8.6
8.4
8.2
6.2
00077
TRANSP O
<=ECCHl FIELD
INCHES M]
182
94
TVY
MHO
799
820
fll8
795
800
795
790
00400
PH
su
7.99
8.10
8.04
8.00
8.03
7.98
7.79
00410
T ALK
CAC03
MG/L
131
131
133
136
136
136
147
00610
NH3-N
TOTAL
MG/L
0.040
0.030
0.030
0.040
0.050
0.070
0.050
00625
TOT KJEL
N
MG/L
0.200K
0.200
0.200K
0.200K
0.200K
0.200K
o.aooK
00630
N02&N03
N-TOTAL
MG/L
O.P40
O.?30
O.P30
O.?40
O.?40
0.240
0.430
00671
PHOS-DIS
OP.THO
MG/L P
0.005
0.004
0.005
o.oos
0.005
0.010
O.OOM
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/12/11
10 40 0000
10 40 0005
10 40 0015
10 40 0030
10 40 0050
10 40 0100
10 40 0215
0665
S-TOT
/L P
0.015
0.021
0.010
0.019
0.017
0.018
0.015
32217
CHLRPHYL
A
UG/L
3.1
00031
IN'CDT LT
RFMNilNG
PFRCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOHET RETRIEVAL DATE 77/01/32
NATL EUT«OPHICATION SURVEY
EPA-LAS VEGAS
320174
36 01 bO.O 114 43 20.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AM6NT/LAKE
11EPALES 760310 04001002
0438 FEET DEPTH CLASS 00
OATF
FtfO '*
TO
75/12/11
TIME DEPTH
OF
DAY FEET
13 50 0000
13 50 0005
13 50 0015
13 50 0030
13 50 0060
13 50 0100
13 50 0160
13 50 0180
13 50 0220
00010
WATER
TE. HP
CENT
14.3
14.1
14.0
14.0
14.0
14.0
13.5
12.7
11.5
00300
DO
MG/L
8.6
8.4
8.0
8.0
8.0
8.0
7.2
5.6
6.6
00077
TRA^SP Cf>
-------
STOPET RETRIEVAL DATE 77/01/32
NATL EUTROPMICATIOK' SURVEY
EPA-LAS VEGAS
320175
36 04 08.0 114 47 30.0 3
LAKE MEAD
32003 NEVADA
/TYPA/AMBNT/LAKE
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/12/10 15 10 0000
15 10 0005
15 10 001S
15 10 0030
15 10 0050
15 10 0075
15 10 0100
15 10 0150
15 10 0170
15 10 0180
15 10 0200
11EPALES 760303 04001002
0210 FEET OEPTH CLASS 00
oonio
WATER
TEMP
CENT
14.2
14.1
14.0
14. n
14. n
13. «
13. 8
13. 3
13. S
12. P.
11.9
00300
00
MG/L
8.6
8.6
7.2
8.6
8.2
8.0
8.2
8.2
7.8
S.6
5.8
00077 00094
TKANSP CNDUCTVY
<:ECCHl FIELD
INCHES MICROMHO
120 794
796
796
795
794
793
790
817
787
767
742
00400
PH
su
7.60
7.60
7.55
7.50
7.50
7.49
7.48
7.41
7.39
7.20
7.22
00410
T ALK
CAC03
MG/L
121
123
123
124
122
, 120
121
122
124
129
132
00610
NH3-N
TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020
0.020
0.030
0.030
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
00630
N02S.Nf13
N-TOTAL
MG/L
0.230
O.?30
O.?30
0.230
0.230
O.?20
0.220
0.230
0.270
0.410
0.420
00671
PHOS-DIS
OBTHO
MG/L P
0.006
0.006
0.006
0.006
0.007
0.010
0.011
0.013
0.020
0.019
0.014
OATE TIME DEPTH PHOS-TOT
FRO" OF
TO DAY FEET
75/12/10 15 10 0000
15 10 0006
15 10 001
y.0,29
0.017
00031
IMCDT LT
RFMNING
PFRCtNT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STOWET BE.Taifc.V4L DATE 77/01/32
NATL t'UTWOPHICATIOM SURVEY
VEGAS
320176
36 03 14.0 114 47 56.0
LAKE MEAD
33003 NEVADA
/TYPA/AMPM/LAKE
00010
DATE
TO
75/12/11
TIME DEPTH ,
OF
DAY FEET
09
09
09
09
09
09
09
20
20
20
20
20
20
20
0000
OOOS
0015
0030
0050
0100
0124
(ATE*
TEMP
CENT
13.9
14.0
13.9
13.9
13.9
13. R
13.7
00300
DO
MG/L
8.2
B.2
8.2
8.6
8.2
8.0
7.4
00077
CECCHI FIELD
INCHES MI
168
HEPALES 760303 04001002
0124 FEET DEPTH CLASS 00
94
TVY
MHO
795
800
800
797
797
797
795
00400
PH
SU
7.96
7.91
7.93
7.92
7.90
7.84
7.96
00410
T ALK
CAC03
MG/L
126
126
128
128
129
128
126
00610
NH3-N
TOTAL
MG/L
0.040
0.040
0.040
0.030
0.050
0.050
0.060
00625
TOT KJEL
N
MG/L
0.200K
0.200
0.200K
0.200K
0.200K
0.200K
0.400
00630
N02&N03
N-TOTAL
MG/l.
O.?40
O.?40
O.?40
O.?30
O.?40
O.?40
O.P50
00671
PHOS-DIS
OPTHO
MG/L P
0.005
0.008
0.006
0.005
o.ooe
0.011
0.012
00665 32217
DATE TIME DEPTH PHOS-TOT CHL^iPHYL
FRO* Or" A
TO DAY FEET MG/L P UG/L
75/12/11 09 20 0001 O.Olfl 3.4
09 20 000=. 0.01P
09 20 0015 0.018
09 20 0030 0.016
09 20 0050 0.019
09 20 0100 0.025
09 20 0124 0.021
00031
INGOT LT
PFMNIN6
PFRCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
APPENDIX D
TRIBUTARY AND WASTEWATER
TREATMENT PLANT DATA
-------
STORET RETRIEVAL DATE 77/01/22
NATL EUTPOPHICATION SURVEY
EPA- LAS VEGAS
/TYPA/AM8NT/STREAM
3201A1
36 00 55.0 114 *4 16.0 4
COLORADO RIVER
32 15 HOOVER DAM
0/LAKE MEAD
SAMPLE AT BASE OF HOOVER DAM
11EPALES 04001004
0000 FEET DEPTH CLASS 00
DATE TIME DEPTH N02a.N03
FROM OF
TO DAY FEET
74/11/16
74/12/20
75/01/28
75/03/17
75/03/28
75/04/23
75/04/29
75/05/17
75/06/30
75/07/31
75/08/20
75/10/28
10
11
12
15
09
11
10
10
11
09
09
09
00
30
on
52
30
35
10
50
25
10
15
25
0630
4.N03
OTAL
l(3/L
0.464
0.44fl
0.336
0.340
0.34S
0.170
0.360
0.08^
0.015
0.005
0.410
(1.420
00625
TOT KJEL
N
MG/L
0.900
0.900
0.900
0.400
0.800
1.100
0.650
0.900
1.600
0.600
0.950
1.100
00610
NH3-N
TOTAL
MG/L
0.045
0.015
0.024
0.025
0.025
0.030
0.030
0.055
0.030
0.015
0.020
0.010
00671
PHOS-DIS
ORTHO
MG/L P
0.010
0.010
0.020
0.020
0.020
0.040
0.025
0.005K
0.005K
0.010
0.015
0.015
00665
PHOS-TOT
MG/L P
0.010
0.010
0.030
0.030
0.030
0.077
0.030
0.010K
0.010
0.020
0.030
0.020
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
NATL EUTROPHICATIG"':
EPA- LAS VEGAS
/TYPA/AMBNT/STREA
3201A2
35 47 00.0 114 50 48.0 4
COLORADO FUVEH
32 MOHAVE CO A2 GEN
T/LAKE MEAD 110191
8NK SAMP OFF END OF SEC RD AT PEACH
11EPALES 04001004
0000 KEET DEPTH CLASS 00
DATE
TO
TIME DEPTH
OF
DAY
FEET
74/12/13 10 45
75/02/18 16 45
75/03/17 16 on
75/04/17 14 00
00630
)2kN03
006?5
TOT KJEL
N-TOTAL N
MG/L
0 .
-------
STOPET RETPIEVAL DATE 77/01/22
NATl EUT*OPhICATIO'\i SURVEY
EPA- i_AS VEGAS
/TYPA/AMBNT/STP.EAM
3201C1
36 33 20.0 114 26 30.0 4
MUDDY RIVE*
32 15 OVERTON
T/LAKE MEAD 110191
SEC HD SHOG 1 Ml N OF OVEPTON
11EPALES 04001004
0000 FEET DEHTH CLASS 00
DATE
(•ROM
TO
74/11/16
74/12/20
75/01/?8
75/03/20
75/03/28
75/04/23
75/04/29
75/05/17
75/06/30
75/07/31
75/08/20
75/10/28
00630 00625
TIME DEPTH N02>i,N03 TOT KJEL
OF N-TOTAL N
DAY FEET
13
13
14
18
I'd
13
12
12
13
1?
11
12
00
25
20
00
15
20
00
40
25
15
10
05
MG/L
0
0
n
0
0
n
0
0
0
0
0
0
.336
.336
.335
.250
.410
.34S
.300
.37(1
.300
.360
.300
.580
MG/L
1.
1.
1.
1.
1.
1.
1 .
1.
0.
2.
1.
1.
000
200
225
950
800
200
700
250
550
100
700
700
00610 00671 00665
MH3-N PHOS-DIS PHOS-TOT
TOTAL ORTHQ
MG/L
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
055
030
064
090
0?5
070
0«5
055
0?5
070
035
045
MG/L
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
P
015
030
082
065
075
080
095
060
210
125
080
110
MG/L P
0.250
0.140
0.237
1.100
0.660
0.320
0.270
0.275
0.250
0.360
0.270
0.350
-------
STO-ET RETRIEVAL
NATL
EPA- LAS VEGAS
E 77/Q1/??
3201D1
36 44 05.0 114 13 10.0 4
VIRGIN RIVER
32 15 VIRGIN PEAK
T/LAKE MEAD
SEC HO 541
11EPALES
110491
3RDG 6 MI SW OF BilNKEPVILLE
04001004
0000 FEET DEPTH CLASS 00
DATE
FROM
TO
74/11/16
74/13/20
75/01/29
75/03/20
75/03/2b
75/04/23
75/04/29
75/05/17
75/06/30
75/07/31
75/08/20
TIME OEPT>-
OF
DAY FEET
14
14
15
19
13
14
14
13
14
15
13
on
na
25
IS
25
15
20
40
30
SO
OS
00630 00625
' N02tyN03 TOT KjEL
N-TOTAL N
MG/L
0
0
i)
0
0
0
0
0
0
u
1)
.384
.384
.312
.310
.260
.100
.030
.470
.440
.470
.005
MG/L
1.
0.
0.
4.
2.
1.
0.
2.
1.
1.
0.
500
700
600
300
700
100
600
100
4t>0
000
500
00610 00671 00665
MH3-N PHOS-DIS PHOS-TOT
TOTAL ORTHO
MG/L MG/L P
0.
0.
0.
0.
0.
n.
0.
0.
0.
0.
0.
075
055
056
030
030
040
070
045
no '
155
()?b
0
0
0
0
0
0
0
0
0
.015
.360
.250
.015
.005
.020
.105
.075
.010
MG/L P
0.560
0.220
0.340
4.200
4.200
0.130
0.120
1.000
0.513
0.195
0.040
-------
STORE! RETRIEVAL DATE 77/02/24
NATL EUTBOPHICATION SURVEY
EPA- LAS VE6AS
/AMBNT/STREAM
DATE
FROM
TO
74/11/20
CP(T)-
74/11/21
74/12/11
CP(T)-
74/12/12
75/01/22
CP(T)-
75/01/23
75/02/19
CP(T>-
75/02/20
75/03/19
CP(T)-
75/03/20
75/04/16
CP(T>-
75/04/17
75/05/21
CP-
75/05/22
75/06/18
CP-
75/06/19
75/08/07
cpm-
75/08/07
75/09/10
CP(T)-
75/09/11
75/10/16
CP(T)-
75/10/16
75/11/13
00610
TIME DEPTH N02&N03
OF N-TOTAL
DAY FEET MG/L
06
06
10
06
04
06
08
06
08
06
10
06
10
06
10
06
00
22
08
06
00
22
22
30
30
30
30
30
30
30
30
30
30
30
30
30
30
00
00
00
00
30
30
00
00
00
3
1
0
1
0
1
2
3
0
1
1
1
.680
.740
.«80
.040
.8*0
.750
.000
.300
.600
.650
.600
.800
00625
TOT KJEL
N
MG/L
15
17
23
23
21
21
16
17
18
16
18
23
.000
.000
.000
.000
.000
.000
.000
.000
.500
.800
.000
.000
3201EA TF3201EA P218000
36 08 30.0 115 03 10.0 *
LAS VfcSAS
32 15 LAS VEGAS
T/LAKE MEAD 110191
LAS VEGAS MASH
11EPALES 00001004
0000 FEET OEHTH CLASS 00
00610 00671 00665 50051 50051
MH3-N PHOS-DIS PHOS-TOT FLOW CONDUIT
TOTAL ORTHO RATE FLOw-MGD
MG/L MG/L P MG/L P 1NST MGO MONTHLY
3.900
5.600
8.800 6.000
8.000 5.900
8.100 5.600
4.900 4.700
7.100
12.700 12.300
4.800 5.500 7.400 12.500 12.800
7.300 11.200 12.700
7.400 11.100 12.400
7.300 11.700 12.900
7.600 11.700 13.100
4.800 6.200 6.600 ll.HOO 13.200
!.600 5.700 6.750 12.600 13.200
6.500 12.500 13.000
3.900 5.400 6.350 11.900 13.900
4.700 5.600 8.100 11.300 13.100
6.400 5.600 7.100 11.000 12.500
-------
STORET RETRIEVAL DATE 77/03/24
NATL EUTROPHICATION SURVEY
EPA- LAS VEGAS
/AMBNT/STREAM
DATE TIME DEPTH N026.N03
FROM OF
TO DAY FEET
74/11/20
75/01/10
75/02/11
75/03/11
75/04/15
75/05/31
75/07/02
75/08/08
75/09/18
75/10/17
75/11/13
75/12/12
76/01/09
76/02/22
09 30
09 30
09 00
09 00
10 00
09 00
09 00
09 00
09 30
09 30
09 30
09 IS
09 30
3201£a TF3201EB ^056000
36 07 30.0 115 0? 05.0 4
CLAKK CO. E. OUTFALL
32 15 LAS VEGAS
T/LAKE MEAD 110191
LAS VEGAS WASH
11EPALES 00001004
0000 FEET DEPTH CLASS 00
0630
6.N03
OTAL
G/L
1.120
0.40n
0.080
0.560
0.950
2.00n
1.100
4.400
2.200
1.450
0.725
0.800
0.600
1.100
00625
TOT KJEL
N
MG/L
16.000
23.000
11.000
25.000
18.000
18.500
17.500
19.500
16.500
21.000
22.000
21.000
23.000
15.000
00610
MH3-N
TOTAL
MG/L
6.400
6.500
6. 287
fl.030
2.400
4.000
4.700
0.640
4.600
7.300
2.700
5.200
3.300
00671
PHOS-DIS
ORTHO
MG/L P
6.600
5.800
6.875
8.230
5.700
6.200
5.700
5.400
7.200
6.600
6.300
6.SOO
4.500
00665
PHOS-TOT
MG/L P
7.100
6.600
7.000
8.400
7.700
5.800
6.950
6.800
6.500
7.900
7.700
8.800
8.100
5.200
50051
FLOW
RATE
INST MGD
12.700
12.400
22.200
14.100
10.300
14.600
15.100
13.700
15.400
15.260
15.600
15.670
15.600
17.700
50053
CONDUIT
FLOW-MGD
MONTHLY
10.400
12.400
9.690
13.170
13.440
14.170
14.100
13.410
15.170
15.310
16.070
15.860
16.330
17.720
-------
STORET RETRIEVAL DATE 77/02/24
NATL EUTROPHICATIO. SURVEY
EPA- LAS VEGAS
/AMBNT/STREAM
DATE TIME DEPTH N02S.N03
FROM OF
TO DAY FEET
74/11/20
75/01/10
75/02/11
75/03/11
75/04/15
75/05/31
75/07/02
75/08/08
75/09/18
75/10/17
75/11/13
75/12/12
76/01/09
76/02/22
76/03/12
09 3"
09 30
09 00
09 00
10 on
09 00
09 00
09 00
09 30
09 30
09 30
09 15
09 30
09 30
3201EC TF3201EC M056000
36 07 30.0 115 02 05.0 4
CLAfiiv CO. *. OUTFALL
32 15 LAS VEGAS
T/LAKE MEAD 110191
LAS VEGAS WASH
11EPALES 00001004
0000 FEET DEPTH CLASS 00
0630
S.N03
OTAL
G/L
1.200
0.080
0.400
0.480
1.490
0.350
0.300
0.050
0.925
1.880
o.?on
1 .300
0.450
0.850
0.725
0062b
TOT KJEL
N
MG/L
20.000
29.000
9.500
25.000
20.000
28.000
19.000
25.000
23.000
21.000
30.000
22.500
32.000
19.000
22.000
00610
NH3-N
TOTAL
MG/L
5.HOO
7.500
5.9213
8.330
11.400
13.000
ll.HOO
5.300
3.700
3.100
13.500
5.200
7.700
5.100
5.300
00671
PHOS-OIS
ORTHO
MG/L f
5.500
6.500
6.000
7.760
5.950
6.fOO
5.400
6.300
5.400
5.SOO
6.?00
6.600
6.900
1.500
5.400
00665
PHOS-TOT
MG/L P
7.100
7.900
6.900
7.900
8.000
6.400
7.050
8.100
7.000
6.500
7.250
9.000
8.:ioo
2.400
7.000
50051
FLOW
SATE
INST MGD
10.100
9.500
^.600
10.600
10.250
10.500
11.100
14.200
11.900
11.390
9.620
9.370
9.36D
10.400
25.700
50053
CONDUIT
FLOW-MGO
MONTHLY
11.200
9.04Q
12.600
10.010
10.190
10.500
13.060
13.820
12.260
11.640
10.140
9.420
9.5«5
10.360
9.826
-------
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 DAT,1 TO BE USED IN RANKINGS
LAKE
CODE LAKE NAME
3201 LAKE MEAD
3202 LAHOMTAN RESERVOIR
3204 RYE PATCH RESERVOIR
3205 LAKE TA.HCE
3206 TOPAZ RESERVOIR
3207 UPPER PAHRANSAT LAKE
3203 wASHOE LAKE
3209 WILD HORSE RESERUQIR
3210 WILSON RESERVOIR
3211 '.'.'ALKilK LAKE
MEDIAN
TOTAL ?
0.016
0.19S
0.09*
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
266.555
472.083
467.750
-3.269
376.000
470.000
494.555
439.400
197.333
405.333
MEAN
CHLORA
3.111
4.608
4.933
0.571
7.517
—
11.633
75.530
10.033
3.422
15-
KIN 00
11.400
10.400
10.000
10.200
14.500
3.500
7.200
14.600
11.400
15.000
MEDIAN
DISS GPJHO P
Q.005
0.143
0.039
0.003
0.041
0.026
0.263
0.065
0.016
0.574
-------
PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES)
LAKE
CODE LAKE NAME,
3201 LAKE MEAD
3202 LAHONTAN RESERVOIR
3204 RYE PATCH RESERVOIR
3205 LAKE TAHOE
3205 TCPAZ RESERVOIR
3207 UPPER PAHRANAGAT LAKE
3208 WASHOl 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)
HF.OIAN
I.?JORG. N
11 (
0 (
89 (
100 (
33 (
56 (
44 (
22 (.
67 {
78 (
1)
0)
8)
9)
3)
5)
4)
2)
6)
7)
500-
MEAN SEC
73 (
22 t
44 (
100 (
67 (
33 (
0 (
11 (
89 (
56 (
7)
2)
4)
9)
6)
3)
0)
1)
8)
5)
f'.EAN
CHLORA
88 (
63 (
50 (
100 (
38 (
—
13 (
0 (
25 (
75 (.
7)
5)
4)
8)
3)
1)
0)
2)
6)
15-
MIN DO
39 (
56 (.
78 (
67 (
17 (
89 (
100 (
17 (
39 (
0 (
3)
5)
7)
6)
1)
8)
9)
1)
3)
0)
MEDIAN
DISS ORTHO P
£9 (
22 (
55 (
100 (
44 (
67 (
11 (
33 (
78 (
o C
8)
2}
5)
9)
4)
6)
1)
-j i
7)
0}
------- |